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Notes by: Michelle Dos Santos Lecture by: Sahil Misri Page 1 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriAbdominal Pain Assessment of acute abdomen “Acute abdomen” → rapid onset of severe symptoms of abdominal pathology → may indicate a potentially life-threatening condition that requires urgent surgical intervention → common reason for ED attendance Clinical features: • immediate assessment should distinguish patients with true acute abdomen that require urgent surgical intervention from patients who can initially be managed conservatively • access to an experienced surgeon reduces unnecessary admissions • patients with acute surgical pathology may deteriorate rapidly; patients with severe, unremitting symptoms warrant thorough investigation and close monitoring Pain may: • be located in any quadrant of the abdomen • be intermittent, sharp or dull, achy, or piercing • radiate from a focal site • be accompanied by nausea and vomiting • be absent in older people, children, the immunocompromised, and in the last trimester of pregnancy Diagnostic work-up: • an acute abdomen is diagnosed by a combination of history, physical examination, imaging, and laboratory results. • diagnostic laparoscopy can be considered in selected patients Analgesia: • opioid analgesia does not increase the risk of diagnosis/treatment decision error • improves patient comfort Special groups Abdominal pain in older people, the immunocompromised, and pregnant women often presents atypically, which can lead to delayed diagnosis of life-threatening abdominal pathology. Older people • comorbid conditions/medications may affect physiological response • are at higher risk for more severe disease due to decreased immune function • decreased CNS function can restrict an ability to communicate problems • decreased PNS function can alter perception of pain and temperature Pregnant women • many physical and physiological changes • enlarged uterus displaces and compresses intra-abdominal organs • laxity of the abdominal wall makes it difficult to localise pain and can blunt peritoneal signs • may have a mild physiological leukocytosis, so this finding is non-specific in pregnant women presenting with an acute abdomen Page 2 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri • high suspicion for intra-abdominal pathology → further studies are warranted e.g. additional laboratory testing, radiographic testing, serial physical examinations Immunocompromised patients • altered inflammatory response • atypical symptoms and signs • abdominal pain is usually non-specific, and physical examination is often inconclusive • susceptible to opportunistic infections, e.g. cytomegalovirus colitis in AIDS patients • acute abdomen may occur as a result of immunosuppressive therapy; typhlitis (neutropenic enterocolitis) is a complication of chemotherapy that typically presents with fever, neutropenia, and right iliac fossa pain 10 to 14 days after initiation of chemotherapy • a lower threshold for hospital admission and cross-sectional imaging is required Differentials Common Uncommon adhesions, Volvulus, intussusception, perforated duodenal incarcerated/strangulated hernia, ulcer, ovarian torsion, abdominal aortic dissection, cholecystitis, perforated gastric ruptured aortic aneurysm, acute mesenteric ulcer, appendicitis, ectopic ischaemia and infarction, myocardial infarction, pregnancy, pelvic inflammatory Meckel’s diverticulitis, oesophageal perforation disease, acute pancreatitis, acute (Boerhaave’s syndrome), ischaemic colitis, diverticulitis, gastrointestinal ruptured splenic artery aneurysm, Budd-Chiari malignancy, diabetic ketoacidosis syndrome, splenic infarct, typhlitis (neutropenic enterocolitis) ulcerative colitis, Crohn’s disease, Ruptured ovarian cyst, hepatic abscess, psoas cholelithiasis, Mallory-Weiss tear, abscess, tuberculosis, Fitz-Hugh Curtis syndrome, opioid withdrawal, hepatitis, abdominal wall haematoma, uraemia, Addisonian gastroenteritis, infectious colitis, crisis, hypercalcaemia, acute intermittent sickle cell crisis, endometriosis, porphyria, hereditary Mediterranean fever, testicular torsion, kidney stones, radiation enteritis, heavy metal poisoning, spider pyelonephritis bite Aetiology commonest causes of acute abdomen: Likely aetiology varies according to age; • nonspecific abdominal pain →renal colic and appendicitis are • renal colic more common in patients <60 years • biliary colic → gallbladder disease and • cholecystitis diverticulitis are more common in • appendicitis older patients • diverticulitis GI causes: Page 3 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriInflammation causing peritonitis (e.g., appendicitis, diverticulitis, Meckel's diverticulitis), bowel obstruction, perforated viscus, or infection: • bowel obstruction occurs when there is a mechanical interruption to the flow of intestinal contents o intra-abdominal adhesions from previous surgery and incarcerated hernia → small bowel obstruction o colorectal tumour, large bowel volvulus, stricture → large bowel obstruction • causes of perforation: o gastric or duodenal ulcer o untreated inflammation o obstruction • oesophageal perforation (Boerhaave's syndrome) and Mallory-Weiss tear result in oesophageal laceration and GI haemorrhage • Ulcerative colitis and Crohn's disease may present with abdominal pain secondary to the inflammatory process or due to the complication of obstruction • Infective processes include gastroenteritis, infectious colitis, and typhlitis (neutropenic enterocolitis). GU causes: • renal and ureteric • obstructed renal and ureteric stones signs/symptoms = renal colic: stones o severe, acute flank pain that may radiate to the ipsilateral groin o commonly associated with nausea and vomiting • pyelonephritis o rarely accompanied by macroscopic haematuria • testicular torsion o as stones pass and get lodged in the distal ureter or intramural • ectopic pregnancy tunnel, this can lead to bladder irritation manifested as urinary • ruptured ovarian cyst frequency or urgency • ovarian torsion o ipsilateral testicular and groin pain may occur rarely in men • pelvic inflammatory with obstructive stones disease • pyelonephritis signs/symptoms: o acute-onset fever, chills • endometriosis o severe back or flank pain o nausea and vomiting o costovertebral angle tenderness Hepatobiliary and pancreatic causes: • Biliary colic o steady, severe pain in the RUQ o symptoms last between 15 minutes and 5 hours. • Cholecystitis o biliary pain lasting more than 5 hours o accompanied by features of inflammation, e.g., fever, marked RUQ tenderness, leukocytosis • Pancreatitis o sudden onset epigastric or LUQ pain which may radiate to the back o nausea and vomiting o common causes are gallstones and excessive alcohol consumption Infectious causes include: • Hepatitis Page 4 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri • Hepatic abscess • Fitz-Hugh Curtis syndrome o complication of pelvic inflammatory disease o RUQ abdominal pain o associated with perihepatitis Vascular causes: • intra-abdominal haemorrhages: o abdominal aortic dissection o ruptured aortic aneurysm o ruptured splenic artery aneurysm. • ischaemia: o acute mesenteric ischaemia and infarction o ischaemic colitis o splenic infarct (LUQ pain) • Vaso-occlusive episodes in sickle cell crises • Budd-Chiari syndrome: o involves hepatic venous outflow obstruction o may present with hepatomegaly and ascites Metabolic and toxic causes: Metabolic causes: • uraemia Toxic causes: • diabetic ketoacidosis • Heavy metal poisoning • Addisonian crisis o may be caused by • Hypercalcaemia medical/environmental/occupational Inherited disorders: exposure (e.g., mercury, lead, arsenic) • acute intermittent porphyria • Withdrawal from opioids • hereditary Mediterranean fever o may result in abdominal cramping pain Musculoskeletal causes: • Psoas abscess: o due to a tuberculous abscess which has extended from the lumbar vertebra into the psoas muscle • Abdominal wall haematoma may occur: o spontaneously o secondary to trauma, exercise, coughing, or a procedure Other (less common): • radiation enteritis • spider bites Non-specific abdominal pain (NSAP): • abdominal pain of <7 days' duration • when history, examination, and investigation have not revealed a cause • a diagnosis of exclusion • one study found that it was the most common diagnosis in patients who attended the ED with acute abdominal pain • more common in children than adults • often misdiagnosed Page 5 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri • comorbidity, nausea, vomiting, and leukocytosis at the primary admission are associated with a missed significant diagnosis Urgent considerations • Assess systemically using ABCDE: airway, breathing, circulation, disability, exposure • Monitor vital signs and obtain large bore IV access • Hypovolaemia should be corrected with fluids and/or blood products • O-negative blood can be given until cross-matched blood is available • FBC, serum electrolytes, creatinine, and urea are recommended in all patients; additional tests should be guided by the history • Obtain a surgical consultation before further diagnostic testing to avoid unnecessary work-up and determine whether operative management is needed Ruptured AAA/aortic dissection: • require especially careful fluid management • aggressive fluid resuscitation before surgery is associated with an increased risk of perioperative death, independent of systolic blood pressure • lowest systolic blood pressure <70 mmHg is associated with higher 30-day mortality, compared with lowest systolic blood pressure ≥70 mmHg, in patients undergoing open or endovascular ruptured AAA repair (51% vs. 34%, respectively) • systolic blood pressure is maintained between 80 and 90 mmHg Ectopic pregnancy: • Females of childbearing age should have a pregnancy test to exclude the possibility • If suspected, send blood for blood typing and cross-matching and obtain an urgent gynaecological consultation Ovarian torsion: • Urgent gynaecology consultation is important; the longer an ovary is torsed, the less likely that it can be salvaged Testicular torsion: • Urgent urological consultation should be obtained if suspected Hypovolaemic shock with a haemoperitoneum: • Proceed to surgery with a limited preoperative evaluation Suspected ongoing haemorrhage: • consider giving an antifibrinolytic, such as tranexamic acid Prophylactic antibiotics: • recommended for patients with a perforated viscus, diverticulitis, appendicitis, mesenteric ischaemia, or ruptured AAA • can rapidly develop sepsis • take blood cultures and other microbiological samples before starting antibiotics Myocardial infarction: • consider in patients with epigastric pain, particularly if accompanied by sweating • obtain an ECG and serum troponin measurement; consult a cardiologist immediately if either is abnormal History and clinical evaluation Page 6 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriKey components of the history: • a detailed evaluation of the pain (SOCRATES) • type and time of last meal/other oral intake (information required if surgery is indicated) • past medical and surgical history, medication use, and family history Site of pain (can identify the organ involved): common locations of visceral pain sudden and severe pain colicky, crampy, and intermittent pain gradual/progressive pain RUQ pain: Epigastric pain: LUQ pain: → cholelithiasis → gastric → cholecystitis ulcer/perforation Page 7 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri → hepatitis → pancreatitis → indicate splenic infarct → hepatic abscess → perforated oesophagus or ruptured splenic artery → Fitz-Hugh Curtis → Mallory-Weiss tear aneurysm syndrome → cholelithiasis → pyelonephritis → perforation or → myocardial infarction → kidney stones malignancy of the colon → perforation or → pyelonephritis malignancy of the colon → kidney stones → acute appendicitis in pregnant women due to displacement by the enlarging uterus Periumbilical pain: → appendicitis (may radiate to the right lower quadrant) → acute mesenteric ischaemia → leaking or ruptured abdominal aortic aneurysm → small bowel obstruction RLQ pain: LLQ pain: → appendicitis → sigmoid volvulus → kidney stones (typically older patients) → GI malignancy → diverticulitis → psoas abscess → Crohn's disease → an → ulcerative colitis incarcerated/strangulated → kidney stones hernia → GI malignancy → ovarian torsion or cyst → psoas abscess rupture → an → ectopic pregnancy incarcerated/strangulated → pelvic inflammatory hernia disease (PID) → ovarian torsion or cyst rupture → ectopic pregnancy → pelvic inflammatory disease (PID) → situs inversus and midgut malrotation (uncommon) Persistent lateralised pain: → more likely to indicate a condition associated with ascending or descending colon, kidney, gallbladder or ovary Generalised pain: → possibly caused by perforated viscus Onset and time course of pain Page 8 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriElicit: • the time of onset • whether the pain was sudden or gradual • how it is changing over time Sudden onset pain Intermittent pain Persistent pain Recurrent pain = recurrent condition • perforated • bowel • Diverticulitis • Cholecystitis ulcer obstruction • Pancreatitis • oesophageal • Diverticulitis tear or rupture • nephrolithiasis → with increasing • biliary colic frequency and • acute severity indicating cholecystitis disease progression • pancreatitis • appendicitis Character of pain Elicit whether pain is intermittent, sharp, dull, achy, or piercing. • sharp, localised pain → parietal peritoneum irritation • dull, poorly localised pain felt in the midline → visceral pain • severe pain, unable to find comfortable position → kidney/ureteric stones passing down the ureter • intermittent and colicky pain → adhesions and incarcerated/strangulated hernias • severe, sharp, or tearing pain in the thorax or abdomen → abdominal aortic dissection Radiation and referral of pain • flank radiating to groin pain → renal colic • radiation to the back → pancreatitis, abdominal aortic dissection, or ruptured abdominal aortic aneurysm Classic locations for referred pain and its cause: Page 9 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriSolid circle = primary site, dotted circle = referred pain • Right scapula pain → gallbladder disease, liver disease, or irritation of right hemidiaphragm (e.g., right lower lobe pneumonia) • Left scapula pain → cardiac disease, gastric disease, pancreatic disease, splenic disease, or irritation of left hemidiaphragm • Scrotal or testicular pain (usually pain is radiating from either costophrenic angle to the groin) → kidney stones or ureteral disease Associated GI or systemic symptoms • anorexia → appendicitis (most common), obstructive processes, diverticulitis, hepatic abscess, radiation enteritis, and infectious colitis • fever, chills, nausea, and vomiting → cholecystitis, a ruptured duodenal ulcer, gastric ulcer, appendicitis, acute mesenteric ischaemia, PID, acute diverticulitis, hepatic abscess, hepatitis, abdominal wall haematoma, or spider bites • nature of recent stool: diarrhoea, hard stool, acholic (pale) stool, or presence and appearance of blood and/or mucus → patients with an obstructive process may not have had a recent bowel movement or be able to pass flatus, although bowel motility may continue distal to the obstructed site Presence and nature of exacerbating or relieving factors • medications/other attempts to alleviate symptoms? Page 10 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriExacerbating factors: • eating → cholecystitis and cholelithiasis (especially fatty food), gastric ulcer • movement → appendicitis Relieving factors: • eating that worsens after a few hours → duodenal ulcer Medical and surgical history • prior surgery? o increases the likelihood of an obstruction secondary to adhesions • immunocompromised? • inflammatory bowel disease? o helps to differentiate the likely cause of pain; for example, colitis due to inflammatory bowel disease • recent trauma? • for women; last menstrual period, contraception used, and current pregnancy status? o patients with a known or suspected early pregnancy are at risk for an ectopic pregnancy, particularly if they have not had an ultrasound confirming the location of the pregnancy • cardiovascular disease? o can predispose to aortic aneurysm • atrial fibrillation? o can predispose to mesenteric ischaemia Medication history • Any analgesia or other non-prescription medication taken for symptoms, and its effect. • Any immunosuppressive medication, radiation exposure, or chemotherapy. • Any regular opioid use or dependence (withdrawal can cause acute abdominal pain). • NSAIDs increase the risk of gastric ulceration. • Drugs that can trigger pancreatitis, e.g., corticosteroids, oestrogen, sulfonamides, tetracycline. Social history • Excessive alcohol consumption is a risk factor for pancreatitis. • Travel history: ask about visits to areas endemic for amoebiasis (hepatic abscess), or areas that have insanitary conditions (gastroenteritis and infectious colitis). • Environmental or occupational history consistent with heavy metal exposure. Family history • In patients with suspected gastroenteritis, check whether other family members have similar symptoms. • A positive family history may raise suspicion for nephrolithiasis, inflammatory bowel disease, hereditary Mediterranean fever, or acute intermittent porphyria. Inspection General assessment of how ill the patient appears: Page 11 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri • in pain and moving around unable to find a comfortable position → renal colic • still and reluctant to move → peritonitis • abdominal scars → clues to previous and current pathology and the likelihood of adhesions • generalised abdominal distension or local bulges → bowel obstruction, hernia, or mass • skin changes, particularly over hernia sites, can signify strangulation with blanching erythema, discoloration, or even ulceration in late stages • periumbilical discoloration (Cullen's sign) or bruising of the flanks (Grey-Turner's sign) → haemorrhagic pancreatitis Cullen’s sign: Grey-Turner’s sign: Auscultation Abdomen: • Small or large bowel obstruction: o hyperactive 'tinkling' bowel sounds in the early course o reduced or absent bowel sounds & distended abdomen in the late course • perforated viscus, haemoperitoneum, or other conditions with peritoneal inflammation: o bowel sounds possibly absent Chest: • increased vocal resonance and reduced breath sounds; pneumonia • reduced heart sounds and/or a pericardial rub; pericarditis → may be giving rise to the symptoms of an acute abdomen Palpation • rigid abdomen o hallmark sign for an acute abdomen o implies severe peritoneal irritation with reflex involuntary guarding o only encountered with perforated peptic ulcer (with generalised release of gastric acid) • rebound tenderness/evidence of peritoneal irritation o any condition where there is irritation of the parietal peritoneum e.g. appendicitis, diverticulitis o also seen in advanced obstruction and volvulus • false pain o patients may report abdominal pain to try to obtain opioid analgesia o if suspected, subtly distract the patient during the exam to determine the validity and severity of abdominal signs • Murphy's sign o RUQ tenderness with arrest of inhalation during palpation o may be present with cholecystitis • palpable and irreducible hernia o may be detected in patients with incarcerated hernia Page 12 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri o the groin should be examined in all patients with symptoms or signs of bowel obstruction o palpable masses may also be detected in patients with cholecystitis, appendix mass, intussusception, or aortic aneurysm (pulsatile) • Psoas sign, Rovsing's sign, pain on coughing, or pain on hopping o highly specific but not sensitive for paediatric appendicitis Percussion • if percussion induces pain, peritoneal inflammation may be present • also used to detect the presence of shifting dullness Rectal examination May reveal: • blood → acute diverticulitis, volvulus, intussusception (often mixed with mucus, often described as 'currant jelly'); present with acute abdomen → haemorrhoids, upper GI bleeding, lower GI tumours; don’t present with acute abdomen • faecal impaction • tumour • enlarged prostate • pelvic abscess Pelvic examination • indicated for most women with lower abdominal pain • assists the diagnosis/exclusion of ovarian torsion, an ectopic pregnancy, or PID • PID: o cervical motion tenderness and adnexal tenderness will be present o bimanual examination may reveal a tubo-ovarian abscess • Ectopic pregnancy: o often a palpable adnexal mass with or without tenderness o vaginal bleeding on speculum examination • Ovarian torsion: o severe, unilateral adnexal tenderness o palpable adnexal mass Scrotal/testicular examination • tenderness: o can signify epididymitis or testicular torsion o early urology consult is important as the longer the testicle is torsed the less likely that it can be salvaged • inguinal hernia examination: o some inguinal hernias can track down into the scrotum through a patent processus vaginalis o both inguinal canals should be examined even though a hernia may present on only one side Diagnostic tools • diagnostic accuracy may be improved by using algorithms or decision tools • The Appendicitis Inflammatory Response (AIR) score and the Pediatric Appendicitis Risk Calculator (pARC) have been shown to help stratify risk of appendicitis in patients presenting with acute abdominal pain Page 13 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriLaboratory tests • often non-specific • used to support clinical findings and medical expertise Initial tests to order for all patients: • FBC: leukocytosis is often (but not invariably) present in conditions such as appendicitis, cholecystitis, PID, duodenal and gastric ulcer, acute mesenteric ischemia, intussusception, hepatic abscess, pyelonephritis, strangulated hernia, pancreatitis, diverticulitis, and infectious colitis • Serum electrolytes panel that includes sodium, potassium, chloride, bicarbonate, urea, creatinine, and glucose: o hypochloraemia and hypokalaemia may occur in the latter stages of intestinal obstruction o glucose may be elevated in pancreatitis if insulin secretion is compromised o serum urea may be elevated in patients with abdominal aortic dissection or aneurysm if the renal arteries are compromised • Urinalysis: o can identify urinary infection (pyelonephritis) o can rule out renal or urinary source of pain (e.g., kidney stone) o likely to have abnormal results in uraemia • Pregnancy test: o for all women of reproductive age o to rule out ectopic pregnancy o for considering treatments If diagnosis is not definitive from the physical examination, laboratory analysis, or radiographic evaluation, the following tests may be helpful: • Comprehensive metabolic panel o basic electrolytes with liver function tests (aminotransferases, bilirubin, and alkaline phosphatase). • Coagulation studies o patients with suspected vascular causes of abdominal pain, including an aortic dissection, ruptured aortic aneurysm, or acute mesenteric ischaemia, o unstable patients, especially if surgery is indicated • Serum amylase and lipase levels o significantly elevated levels are the hallmark of acute pancreatitis (threshold is >3x normal) o serum lipase testing > serum amylase testing; serum lipase and amylase have similar sensitivity and specificity, but lipase levels remain elevated for longer (up to 14 days after symptom onset vs. 5 days for amylase) o it is important to have a low threshold for admitting and treating patients whose symptoms are suggestive of acute pancreatitis, even if these tests are normal as serum lipase/amylase testing isn’t very sensitive o about a quarter of people with acute pancreatitis fail to be diagnosed as having acute pancreatitis with serum amylase and serum lipase test o about 1 in 10 patients without acute pancreatitis may be wrongly diagnosed as having acute pancreatitis with these tests Page 14 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri o it is important to consider other conditions that may require urgent surgery even if these tests are abnormal o serum amylase levels may also be more modestly elevated in other conditions such as ectopic pregnancy, intestinal obstruction, and perforated duodenal ulcer, although amylase levels are not used to diagnose or monitor these conditions • Serum lactic acid levels o elevated in acute mesenteric ischaemia o exact level depends on the severity of ischaemia and the laboratory used o serial measurement may help as a guide for resuscitation Imaging Plain abdominal x-ray: • often performed but rarely changes management • initial imaging test in suspected bowel obstruction or constipation; a positive result may make subsequent imaging unnecessary. • may reveal radiopaque gallstones, renal stones, or pancreatic stones • abdominal wall calcification may indicate the presence of an abdominal aortic aneurysm • loss of the psoas shadow may be noted in the presence of aortic aneurysm rupture Erect chest x-ray if perforation is suspected: • primarily performed to rule out the presence of free air under the diaphragm secondary to a ruptured viscus • if free air is visible, this may preclude the need for additional studies - urgent surgical consultation is recommended • may also be a useful preoperative test for anaesthetists and is often performed in conjunction with plain abdominal x-rays CT of abdomen: • useful for the evaluation of almost all causes of abdominal pain, including obstruction, diverticulitis, pancreatitis, acute appendicitis, intestinal ischaemia, and abdominal aortic aneurysm • IV contrast is usually given, because it increases the range of detectable pathologies; the patient's renal function and risk of contrast-induced acute kidney injury should be considered before IV contrast is administered • CT angiography is recommended for suspected cases of mesenteric ischaemia • non-contrast CT is performed if renal stones are suspected (one retrospective study found that it’s accurate for the clinical triage of patients >75 years who attend ED with acute abdominal pain) • may have a role in pregnancy if ultrasound findings are non-diagnostic/equivocal and MRI is unavailable Ultrasound: • useful for helping diagnose a number of acute abdomen pathologies • usually the first-line imaging test in pregnant women because it does not involve ionising radiation and is not associated with any fetal adverse effects • RUQ US in patients with cholecystitis can reveal: o gallstones o thickened gallbladder wall (>4 mm) Page 15 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri o pericholecystic fluid • Pelvic US in women with an ectopic pregnancy can reveal: o blood in utero o pseudogestational sac in utero o complex mass in adnexa • Doppler US can reveal: o reduced or absent blood flow into a torsed ovary • Ultrasound can also indicate: o presence and size of an abdominal aortic aneurysm o presence of fluid or blood within the peritoneum → this bedside test can be helpful in assessing unstable patients where transfer for CT might be hazardous • The focused assessment with sonography for trauma (FAST): o a limited US examination directed solely at identifying the presence of free intraperitoneal or pericardial fluid o used principally in trauma situations MRI: • has a comparatively limited role in the evaluation of acute abdominal pain • may be diagnostic for an aortic dissection • can be helpful in the assessment of: o pancreatitis o Crohn's disease o endometriosis o psoas abscess • is highly sensitive and specific for the diagnosis of appendicitis in children • useful second-line imaging test in pregnant women, particularly those with suspected appendicitis • gadolinium contrast crosses the placenta and should not be used in pregnancy Fluoroscopy: • contrast enema using air or water • diagnostic and therapeutic procedure for suspected intussusception • diagnostic for volvulus Endoscopy: • oesophagogastroduodenoscopy, sigmoidoscopy, and colonoscopy permit: o direct visualisation of the GI tract mucosa o acquisition of histological specimens • useful in the investigation of: o suspected gastric and duodenal ulcers o inflammatory bowel disease o malignancy Laparoscopy May be considered if patient: • is clinically stable • has no indication for therapeutic surgical intervention • has no apparent cause for their abdominal pain after non-invasive procedures Page 16 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri • has no relative or absolute contraindication to surgery • is a premenopausal woman • a woman of childbearing age with NSAP and suspected appendicitis in these patients laparoscopy is associated with: o a higher rate of specific diagnoses being made o a lower rate of removal of normal appendices compared with open appendicectomy only o shorter hospital stays → laparoscopy can be both diagnostic and therapeutic e.g.: o acute cholecystitis o perforated duodenal or gastric ulcer o appendicitis o lysis of adhesions → there are data to suggest that early laparoscopy is better than active observation in establishing a final diagnosis of NSAP after A&E admission → lack of uniform information does not allow it to be recommended for use in routine clinical practice Cholelithiasis (gallstones) History Exam 1 investigation Other investigations Symptoms: • RUQ/ • LFTs: may be • ERCP*: demonstrates • constant epigastric normal or stones in the gallbladder RUQ/epigastric pain, tenderness elevated or bile duct lasting >30mins, • jaundice alkaline • MRCP**: demonstrates sometimes associated (uncommon phosphatase stones in the gallbladder with food , except for and elevated or bile duct • pain typically Mirizzi bilirubin • endoscopic ultrasound increases in intensity syndrome) • abdominal (EUS)**: stones in Risk factors: ultrasound: gallbladder or bile duct • increasing age demonstrate • pregnancy test: negative • female sex s stones in • obesity (BMI ≥30) the • diabetes and gallbladder • serum metabolic syndrome • family history lipase and • pregnancy amylase: • exogenous oestrogen elevated (>3 times upper • non-alcoholic liver limit of disease • prolonged normal) in fasting/rapid weight acute loss pancreatitis (serum lipase • total parenteral is the nutrition preferred • certain medications (e.g., octreotide, test if patient glucagon-like reports epigastric peptide-1 analogues, pain) ceftriaxone) • terminal ileum disease Page 17 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri • haemoglobinopathies • Native American/Hispanic ethnicity * recommended in patients with a high risk of choledocholithiasis/one of the following: o common bile duct stone seen on ultrasound/cross-sectional imaging o total bilirubin >4mg/dL and dilated common bile duct o ascending cholangitis ** recommended in patients with an intermediate risk of choledocholithiasis/one of the following: o abnormal LFTs o age >55 years o dilated common bile duct on US/cross-sectional imaging Mrs Pritchard patient history • borderline diabetes, GP asked her to lose some weight • no medications/allergies • 3-4 bottles of wine a week (30-40 units), sometimes more • doesn't smoke • has had stomach pains on and off for a year, but never as bad as this • sudden abdominal pain started after dinner, has been happening after eating a lot recently • pain still severe after taking paracetamol • laughing exacerbates pain • difficulty sleeping • nausea & vomited in the morning • sharp pain Page 18 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri• umbilical/epigastric region • no diarrhoea, hasn't felt hot/cold/feverish, just general malaise • doctors took some bloods and gave her stronger painkillers task 1: upper abdominal pain differentials organ vs systems-based differentials organs: • thoracic • heart • aorta → unlikely as she doesn't have any chest pain/shortness of breath/cough → lower lobe pneumonias and angina can present as epigastric pain, especially in women who often have atypical MI symptoms (might have abdominal/GI pain instead of crushing chest pain) GI causes: • pancreas • gallbladder • peptic ulcers • bowel obstruction (more likely to be lower abdominal) systemic causes: • DKA/diabetic ketoacidosis • addisonian crisis • lead poisoning • electrolyte abnormalities e.g. hypocalcaemia other: • food poisoning/gastroenteritis -unlikely as she's only vomited once, doesn't have diarrhoea and isn't febrile • pregnancy task 2: Mrs Pritchard’s most likely diagnosis Mrs Pritchard's blood test results: • high BP & slightly tachycardic (possibly due to pain) • mildly raised WCC • mildly raised neutrophils • mildly raised CRP • normal liver function tests AST = made in hepatocytes, when hepatocytes are damaged enzyme is released so AST is elevated ALP = another liver enzyme, more likely to be raised when there's an obstruction of the liver and specifically bile bilirubin = biochemical marker of jaundice, released when RBC's breakdown Page 19 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri• exam shows RUQ tenderness with a normal respiratory and cardiac examination • combined with her history, this raises the suspicion that the source of her pain is from her gallbladder, specifically due to gallstones (cholelithiasis) 3 main diagnoses linked to gallstones: * biliary colic * cholecystitis * ascending cholangitis how to differentiate based on history, examination, and blood tests: biliary colic cholecystitis ascending cholangitis (bile (symptomatic (gallbladder duct inflammation) cholelithiasis) inflammation) pathology • pain caused by • gallbladder • surgical emergency gallbladder inflammation • biliary outflow obstruction muscle spasms • possible infective & infection against a stone component • gallstone causing a blockage that's stuck in the to biliary flow, either from cystic duct/neck the liver or gallbladder of the gallbladder • high morbidity, and can • no inflammatory sometimes kill response history & • dull RUQ pain • severe & • Charcot's triad: examination • nausea and constant RUQ -jaundice vomiting /epigastric pain -rigors & fevers -RUQ pain • symptoms last for • can get nausea & <6 hours vomiting • sepsis signs & symptoms: • colic suggests that • Murphy's sign on -pain pain comes and examination -rigor & fever goes, but in biliary (place hand on -tacchycardic colic, the pain is RUQ, ask patient -hypotensive more likely to be to breathe in, constant liver & • often triggered by gallbladder move fatty foods (fat down, if inflamed stimulates will press on hand and cause cholecystokinin release → pain, check on gallbladder LUQ to confirm contraction) it's just in the • no jaundice RUQ) • mild temperature and tachycardia blood tests • normal • raised WCC and • raised WCC, CRP, ALP obs/blood test CRP • raised bilirubin (→ • normal • sometimes raised jaundice, just looking at skin LFTs/bilirubin ALP is unreliable) • normal LFTs/bilirubin Page 20 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misritask 3: gallstones causes & risk factors • US confirming gallstones (investigation of choice as its non-ionising radiation and 99% of gallstones don't show on plain x-ray) • majority of gallstones are asymptomatic and can just be picked up on imaging for another reason • only a small percent actually become asymptomatic Causes: Your bile contains too much cholesterol. • normally, your bile contains enough chemicals to dissolve the cholesterol excreted by your liver • if your liver excretes more cholesterol than your bile can dissolve, the excess cholesterol may form into crystals and eventually into stones Your bile contains too much bilirubin. • bilirubin is a chemical that's produced when your body breaks down red blood cells • certain conditions cause your liver to make too much bilirubin, including liver cirrhosis, biliary tract infections and certain blood disorders • the excess bilirubin contributes to gallstone formation Your gallbladder doesn't empty correctly. • if your gallbladder doesn't empty completely or often enough, bile may become very concentrated, contributing to the formation of gallstones Types of gallstones: Cholesterol gallstones (more common). • most common type of gallstone • can vary from light yellow - dark green/brown • most common is yellow • are usually relatively large • are composed mainly of undissolved cholesterol but may contain other components • linked to poor diet and obesity due to excess cholesterol Pigment gallstones. • these dark brown or black stones form when your bile contains too much bilirubin • are more numerous • composed primarily of bilirubin breakdown products • can be from excess bile pigment production, haemolytic anaemia Mixed gallstones (combination of cholesterol + bile pigment + bile salts) Risk factors: • female (oestrogen increases biliary cholesterol secretion) • >40 years-old • Native American or Hispanic of Mexican origin • overweight/obesity • sedentary • pregnant • high-fat diet Page 21 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri • high-cholesterol diet (hyperlipidaemia) • low-fibre diet • FHx of gallstones • diabetes • certain blood disorders e.g. sickle cell anaemia or leukaemia • losing weight very quickly • taking medications that contain oestrogen e.g. oral contraceptives or hormone therapy drugs • liver disease • haemolytic anaemia • Crohn's disease (malabsorption of bile products in terminal ileum) • hypercalcaemia (gallbladder stores) bile: • 98% water • other substances: bile salts, bilirubin, cholesterol, normal other electrolytes present in plasma • gallstones arise from super saturation of bile: can vary in size (grain of sand-golf ball) • composition of gallstones affected by age, diet, ethnicity task 4: gallstones complications • asymptomatic gallstones (majority) • biliary colic -gallstones in the neck of the gallbladder/hartman's pouch/cystic duct -muscle contracts against the gallstone • acute cholecystitis -impacted in cystic duct causing gallbladder inflammation • biliary obstruction/ascending cholangitis -when you get a gallstone blocking the common bile duct -causing blockage of flow from the liver and/or gallbladder Page 22 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri-blockage + infection • gallstone pancreatitis -stone blocking pancreatic duct -back up of pancreatic enzymes causes inflammation -can get severe pain, nausea, vomiting, can radiate towards the back (parts of the pancreas are retroperitoneal) -serum amylase and lipase are raised as they're released into the bloodstream • gallstone ileus -ileus = absence of peristalsis -when a large gallstone enters the duodenum and causes a blockage, causing small bowel obstruction -due to chronic inflammation (perhaps due to gallstones), wall of the gallbladder gets eroded, fistula forms between gallbladder and duodenum -happens over a long period of time -if a large gallstone drops into the duodenum → into the small bowel, gallstone can get impacted at the ileocaecal valve, this is the narrowest point of the small bowel, causing small bowel obstruction -causes vomiting, severe abdominal pain etc. • gallbladder empyema -gallbladder lumen is filled and distended by purulent material pus • Mirizzi syndrome -common hepatic duct obstruction / obstructive jaundice -caused by extrinsic compression from an impacted stone in the cystic duct or infundibulum of the gallbladder -on imaging, no blockage can be seen in the common hepatic duct Other complications: • jaundice, a yellowish tint to your skin or eyes • sepsis, a blood infection • cancer (in any structure with chronic inflammation) Page 23 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misritask 5: gallstone treatment & valid consent no symptoms → no treatment symptomatic gallstones/acute cholelithiasis → laparoscopic cholecystectomy (keyhole surgery to remove the gallbladder) -this is a surgical procedure so requires a written consent form Valid consent requires: • patient to have capacity o GMC guidelines says to assume everyone has capacity, but can gauge capacity when having a meaningful conversation with the patient informed decision making: • need to know about the procedure in order to answer any questions the patient has o good practise for the person taking consent to be involved in the patient's care to allow continuity of care, sometimes isn't the case, in which case need to inform the patient who will be doing the procedure • explain diagnosis & prognosis (how it will develop over time with/without treatment) • treatment options/ what would happen if nothing was done/ what would happen in response to different treatments • purpose, benefits, and risks of procedure has to be written on consent form • risks o personalised to each patient: what their life involves/what they value most, also changes depending on comorbidities of each patient o explain complications • should give the patient time to reflect & make the decision • can recommend treatment options but need to emphasise that it needs to be the patient's own choice Page 24 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misritask 6: risks and complications of laparoscopic cholecystectomy categorising complications: general (any operation) • wound infection • bleeding • scar won't heal properly • post op pain/pain won't subside • blood clots (PE and DVT) • anaesthetic risks e.g. anaphylaxis, allergy, dental damage endotracheal tube is put in, sore throat, awareness under general anaesthetic specific • can damage surrounding structures e.g. liver, bowel, bladder, ureter etc • can lead to haemorrhage from surrounding vessel damage • bile duct injury • converted into open surgery early • keep wounds dry and clean to prevent infection late • if scar doesn't heal properly: hernias through scarred site (smoking is bad for wound healing) Physiology of the Gallbladder introduction • small hollow organ, size and shape of a pear • part of the biliary system/biliary tree/biliary tract • biliary system = series of ducts within the liver, gallbladder, and pancreas that empty into the small intestine • there are intrahepatic (within the liver) and extrahepatic (outside of the liver) components • gallbladder = component of the extrahepatic biliary system where bile is stored and concentrated • bile is a fluid formed in the liver that is essential for digesting fats, excreting cholesterol, and possesses antimicrobial activity • gallbladder lies in the RUQ of the abdomen affixed to the undersurface of the liver at the gallbladder fossa • it is attached to the rest of the extrahepatic biliary system via the cystic duct • the liver produces bile that is drained into the gallbladder and stored until needed for digestion Page 25 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misriissues for concern dysfunction in the physiology of the gallbladder most commonly results in the • production of gallstones • imbalances in the constituents of bile and biliary sludge secondary to gallbladder hypokinesis can lead to the precipitation of insoluble stones • when these gallstones cause physical blockages in the biliary tree and beyond, pain, inflammation, and infection can result in damage to the gallbladder and a host of other organs • many gallbladder pathologies will ultimately warrant surgical intervention/cholecystectomy (one of the most common surgical procedures performed in modern times) cellular • the liver is a large organ located in the RUQ of the abdomen • it's composed of hepatic lobules which are hexagonally shaped functional units of the liver • these lobules are mostly composed of hepatocytes, or liver cells • hepatocytes have many important functions including the production and secretion of bile • hepatic lobules also contain a central vein and portal triads at the periphery consisting of branches of the bile duct, portal vein, and hepatic artery • epithelial lined sinusoids run between the hepatocytes and connect the peripheral vasculature to the central vein • the bile produced by the hepatocytes is drained in the opposite direction of blood flow to the periphery of the lobule by small channels known as the Canals of Hering Page 26 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri• they are lined by simple cuboidal epithelium and ultimately drain the bile into the bile ductule of the portal triad, which will go on to drain into the bile duct • the gallbladder wall is composed of several layers • innermost mucosal layer is made up of columnar epithelium with microvilli; the microvilli increase surface area which is useful for concentrating bile • beneath the mucosa is a lamina propria, a smooth muscle layer, and an outer serosal layer due to its intraperitoneal location development • the gallbladder and biliary system develop from the foregut end of week 4 of embryogenesis: • hepatic diverticulum appears → goes on to become the liver, extrahepatic biliary system, and a portion of the pancreas • the superior bud of the diverticulum develops into the gallbladder at week 6: • common bile duct and part of the pancreas rotate around the duodenum • the bile ducts undergo plugging with epithelial cells and recanalization of their lumens • common bile duct and cystic duct connect by week 7 by week 12: • the gallbladder is no longer solid and the liver is secreting fluid through the patent bile ducts that now empty into the duodenum The development of the biliary system is extremely complex and can lead to numerous variations in its structure. organ systems involved • related organ systems that affect gallbladder physiology include the small intestine, pancreas, and the liver • bile is formed in the liver which is then stored and concentrated in the gallbladder • stimulation of the small intestine by fatty foods and proteins causes the gallbladder to empty the bile into the duodenum • the cystic duct drains the gallbladder and connects with the common bile duct • the common bile duct continues on to merge with the main pancreatic duct at the ampulla of Vater in the pancreas • a gallstone that becomes lodged in the ducts in the pancreas is a leading cause of pancreatitis Page 27 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri• a cholecysto-enteric fistula, or an abnormal connection between the gallbladder and intestines, can lead to a rare form of small bowel obstruction function • the function of the gallbladder is to store and concentrate bile, which is released into the duodenum during digestion • bile is an alkaline fluid continuously produced by the liver whose primary function is to aid in digestion and absorption of lipids, as they are not soluble in water • it is composed of cholesterol, bilirubin, water, bile salts, phospholipids, and ions • the cholesterol excreted into bile eliminates most of the cholesterol in the body • specialized enteroendocrine cells called I-cells are located in the duodenum and jejunum • when these cells are stimulated by fatty acids and amino acids released from the stomach, a peptide hormone called cholecystokinin (CCK) is released CCK has two main functions pertaining to the gallbladder: o stimulate the smooth muscle of the gallbladder to contract and release bile into the biliary tree o simultaneously signal the muscular sphincter of Oddi to relax • after leaving the gallbladder, bile flows down the common bile ducts into a confluence with the main pancreatic duct called the ampulla of Vater • from there, it travels through an opening called the major duodenal papilla into the second portion of the duodenum • the flow through the papilla is controlled by the opening and closing of the sphincter of Oddi • when not stimulated by CCK, the gallbladder relaxes and fills with bile • outside of the gallbladder, CCK stimulates pancreatic secretions necessary for digestion and delays further emptying of the stomach • release of CCK is inhibited by the hormone somatostatin which functions to turn off digestion • bile acids are synthesized in the liver from cholesterol precursor • the rate-limiting step of bile acid production is catalyzed by cholesterol 7α—hydroxylase • the bile acids are conjugated to the amino acids glycine and taurine and become soluble bile salts • these bile salts are important in the process of emulsifying lipids in the intestine • as the lipids are metabolised into free fatty acids and monoglycerides in the digestive tract, they are then packaged into micelles made up of bile salts that act as surfactants • bile salts are able to do this because of their amphipathic nature: o their hydrophilic portions interact with water making them soluble, while their hydrophobic portions keep lipids contained in the centre o the hydrophilic portions are also negatively charged, which repels them from other bile salts and keeps the lipids small and easy to digest • cholesterol and phospholipids are also contained in the structure of the micelles • the bile salts are reabsorbed in the distal ileum of the small intestine and recycled back to the liver in a pathway called the enterohepatic circulation • bilirubin is a yellow pigment that is produced as a breakdown product of heme contained in red blood cells • this compound is initially unconjugated/indirect bilirubin and insoluble in water • the unconjugated bilirubin, is taken up by the liver and conjugated with glucuronate via the enzyme UDP-glucuronosyltransferase • the then conjugated/direct bilirubin, is then excreted into the bile in a soluble form Page 28 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri• the bilirubin contained in bile will eventually travel through the GI system and give urine its yellow colour and stool its brown colour via the breakdown products urobilin and stercobilin, respectively • if bile is unable to enter the duodenum, the build-up of bilirubin leads to jaundice, which is the yellowing of the skin, eyes, and mucus membranes, as well as acholic (pale) stools related testing abdominal ultrasound • initial test of choice to diagnose most disorders of the gallbladder • non-invasive • can effectively evaluate the gallbladder for stones, sludge, and signs of inflammation X-ray • less sensitive, as calcified gallstones are only seen on plain abdominal x-rays in about 10% of patients with cholelithiasis CT scan • often done during an ED visit to evaluate abdominal pain • is very accurate when diagnosing gallbladder disease but exposes the patient to radiation hepatobiliary iminodiacetic acid (HIDA) scan/cholescintigraphy • most sensitive and specific diagnostic test to confirm cholecystitis • is a radionuclide scan where a tracer is given intravenously and is taken up by hepatocytes in the liver • tracer then concentrates in the gallbladder if the cystic duct is patent • typically performed in the setting of an equivocal abdominal ultrasound with clinical suspicion of gallbladder pathology CCK can be administered • to test for the ejection fraction (EF) of the gallbladder • an EF <35% is considered abnormal and indicative of functional gallbladder disorder complete blood count (CBC) and complete metabolic panel (CMP) • are likely to be ordered in the setting of suspected acute gallbladder disease • an elevated WBC, or leukocytosis, would be expected in the setting of inflammation • depending on where a gallstone is located, various enzymes can be elevated, this includes: o the liver enzymes aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) o the pancreatic enzymes lipase and amylase if the pancreas is obstructed • additionally, bilirubin may be elevated • if gamma-glutamyltransferase (GGT) is ordered, it is likely to be elevated as it is found in both hepatocytes and epithelial cells of the gallbladder Pathophysiology of Gallstones Page 29 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriCholelithiasis = gallstones in the gallbladder • normally asymptomatic Biliary colic = gallstones in the cystic duct • characterised by RUQ pain in response to fatty meals, as the lipids stimulate the secretion of CCK which causes painful contractions against the stone Choledocholithiasis = gallstone in the common bile duct • the effects of the lodged stone and subsequent changes in laboratory values are determined by the stone’s location • if the stone has not travelled far, liver enzymes such as ALP, GGT, AST/ALT, and bilirubin are likely to be elevated • if the stone has travelled far enough to reach the pancreas, amylase and lipase will become elevated as a result of pancreatitis Cholecystitis = inflammation of the gallbladder • most commonly due to gallstones in the cystic duct, termed calculous cholecystitis • anytime a duct is obstructed, the resulting stasis can lead to inflammation • compared to biliary colic, acute cholecystitis will likely cause prolonged abdominal pain with associated fever and leukocytosis • the feared complication of untreated acute cholecystitis is infection • besides infection, chronic cholecystitis can occur if the gallbladder undergoes repeated attacks of acute cholecystitis • the resultant scarring and calcification increase the risk of cancer acalculous cholecystitis • another type of cholecystitis can be seen in critically ill patients without gallstones • can occur as a result of infection, low perfusion, or biliary stasis Cholangitis = inflammation of the bile ducts • most commonly this refers to ascending cholangitis, which is secondary to infection • if the biliary tree becomes obstructed the resulting bile stasis can lead to bacterial overgrowth • Charcot triad characterises these symptoms: jaundice (due to elevated bilirubin), fever, and right upper quadrant pain • if the patient shows signs of shock and altered mental status, the collection of signs is then called Reynolds pentad Gallbladder Clinical Significance Page 30 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri• gallbladder disease is common and is a significant medical burden • cholecystectomy is one of the most common surgeries performed • knowledge of gallbladder physiology can aid in the prevention, understanding, and treatment of gallbladder disease • in clinical practice, patients can be counselled on weight loss as obesity is a risk factor for gallbladder disease • those who have been discovered to have asymptomatic cholelithiasis can be educated on the importance of low-fat diets to decrease the incidence of biliary colic • there are many drugs that may increase the risk of gallstone formation e.g. o hormone replacement therapy containing oestrogen causes increased levels of cholesterol o somatostatin analogs such as octreotide block the release of CCK and lead to the formation of biliary sludge o fibrates block the rate-limiting enzyme 7-alpha-hydroxylase causing increased cholesterol and decreased bile acid production • some drugs can make a positive impact on a patient’s health e.g. o bile acid sequestrants that prevent reabsorption of bile acids in the ileum and lead to lower cholesterol levels as the body is forced to use it as a substrate to produce new bile acids • in addition to drug side effects, providers treating patients who are undergoing prolonged periods of fasting or receiving total parenteral nutrition now appreciate that their patients are at increased risk biliary stasis due to the decreased stimulation of CCK cholecystectomies: • most are performed laparoscopically as an outpatient procedure • affords a very low complication rate with a fast recovery • expected intraoperative risks such as perforation and bleeding still exist • an uncommon complication termed post-cholecystectomy syndrome can occur postoperatively as persistent abdominal pain despite the surgery Formation of gallbladder stones • the stones form as a result of imbalances in the constituents of bile and in situations of biliary stasis, which is a state where bile is not flowing • gallstones are usually classified as cholesterol stones or pigmented stones Cholesterol stones • approx. 80-90% of stones • consist mainly of cholesterol (70%) in a matrix of bile pigments, calcium salts and glycoproteins • most often associated with the risk factors remembered by the 4 F’s: female, fat, fertile, and forty • this means that oestrogen, obesity, multiparity, and advancing age are all risk factors • Pigmented stones -are broken down into brown and black stones black stones • composed mainly of calcium bilirubinate • more likely to be seen on radiography • often secondary to pathologies that cause haemolysis Page 31 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri• are found in haemolytic anaemia or ineffective haematopoiesis and in patients with cystic fibrosis • metabolised heme from RBCs causes the increased concentration of bilirubin in bile brown stones • occur secondary to infection • associated with infections of the biliary tract (bacterial and helminthic deconjugation of bilirubin glucuronides) are more frequent in Asia Mixed stones • mixture of cholesterol + pigment 3 major mechanisms for cholesterol gallstone formation: 1. Cholesterol supersaturation • cholesterol is only slightly soluble in aqueous media but is made soluble in bile through mixed micelles with bile salts and phospholipids, mainly phosphatidylcholine (lecithin) • precipitation of cholesterol occurs when cholesterol solubility exceeds the cholesterol saturation index >1 • ternary phase diagrams showing molar bile salt-cholesterolphospholipid percentages demonstrate that cholesterol crystals occur at: → low phospholipid : cholesterol ratios → relative low phospholipid and high bile salt concentrations • multilammellar vesicles then fuse and may aggregate as solid crystals 2. Kinetic factors • the formation of microcrystals in supersaturated bile is modulated by kinetic protein factors • mucin, a glycoprotein mixture that is secreted by biliary epithelial cells, is a crystallization promoting protein in gallbladder sludge 3. Gallbladder hypomotility • as supersaturated bile often is found in healthy individuals, it is assumed that microcrystals formed are effectively flushed from the gallbladder during postprandial contractions • in cholesterol gallstone patients, altered interdigestive gallbladder emptying was observed, and patients with incomplete gallbladder emptying were found to have increased total lipid concentrations • impaired gallbladder motility is commonly seen in several risk groups for cholesterol gallstones, e.g. patients with diabetes mellitus, and rapid weight loss. • on the other hand, once gallstones have formed, the risk for developing symptomatic gallstones disease seems to be higher for those patients who have efficient gallbladder emptying (>70% emptying after a test meal) compared to those with sluggish motility (<55% emptying after a test meal, as estimated by ultrasonography) cholesterol crystals: → aggregate in bile supersaturated with cholesterol → nucleate in the presence of pro-nucleating factors such as mucin → grow stones in an enlarged gallbladder with hypomotility Page 32 of 35 Notes by Michelle Dos Santos and Lecture by Sahil MisriSBA questions: 1. A 24-year-old woman is admitted to A&E with right iliac fossa pain so severe that she’s finding it hard to speak. Initial investigations reveal that her temperature is 38.2 degrees and her white blood cells are elevated. What should you do next? a) ask if she has recently had chemotherapy b) ask her to do a pregnancy test c) immediately administer IV antibiotics d) offer her pain relief Page 33 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri 2. Which of the following are all be consistent with periumbilical pain? a) Large bowel obstruction, appendicitis, ruptured abdominal aortic aneurysm b) Small bowel obstruction, mesenteric artery ischaemia, appendicitis c) Small bowel obstruction, mesenteric artery ischaemia, umbilical hernia d) Leaking abdominal aortic aneurysm, non-specific abdominal pain, GI malignancy 3. A 47-year-old man presents to A&E in the afternoon with RUQ pain. He says it started when he woke up and hasn’t gotten better, but that he hasn’t vomited. What is his most likely diagnosis? a) Non-specific abdominal pain b) Crohn’s disease c) Bowel obstruction d) Cholecystitis 4. What does obstructive abdominal pathology commonly present as? a) Sudden and progressive with radiation b) Colicky and intermittent with anorexia c) Severe and constant with distension d) Crampy epigastric pain with nausea and vomiting 5. Which of the following signs are in keeping with cholecystitis? a) Arrest of inhalation on RUQ palpation, pain on percussion b) Patient still and reluctant to move with absent bowel sounds c) female, fat, fertile, and forty d) palpable mass and elevated glucose 6. Why is serum lipase testing used in preference to serum amylase testing? a) Serum lipase testing has a higher true positive b) Serum lipase testing has a higher true negative c) Serum amylase testing has a lower false negative d) None of the above 7. Mrs H, a 63-year-old female, is driven to A&E by her worried daughter. She said that earlier that morning her mother was complaining of right-sided abdominal pain that moved to her groin. She was also feeling nauseous and vomited. Mrs H looks pale on examination and is hypotensive. What should be done next? a) Urgent MRI scan b) Administer careful IV fluids and prophylactic antibiotics c) Aggressive fluid resuscitation to correct hypovolaemia d) Urgent gynaecology consultation 8. Mr R, a 55-year-old gentleman, complains of intermittent left lower quadrant abdominal pain, fatigue, and increased bowel movements -including during the night. He also reports blood in his stool and says he’s a non-smoker. What would be the most appropriate type of imaging to investigate Mr R’s diagnosis? a) Endoscopy b) Fluoroscopy c) Abdominal X-Ray d) Abdominal CT 9. Which of the following statements about biliary colic, cholecystitis and ascending cholangitis is false? a) RUQ pain is consistent with biliary colic, cholecystitis, and ascending cholangitis Page 34 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri b) Fever and positive Murphy’s signs is only present in cholecystitis c) Nausea and vomiting are associated symptoms of biliary colic and cholecystitis d) Jaundice is only a symptom in ascending cholangitis 10.What could gamma-glutamyltransferase, alkaline phosphatase, and amylase enzymes be elevated in? a) Hepatitis b) Ascending cholangitis c) Choledocholithiasis d) All of the above SBA answers 1. d 2. c 3. d 4. b 5. a 6. d 7. b 8. a 9. b 10.d Page 35 of 35 Notes by Michelle Dos Santos and Lecture by Sahil Misri