Case 9 - Acute Abdomen Flashcards
Name the 3 most common causes of an acute abdomen from the VINDICATE acronym
VIT - vascular, infection/inflammation, trauma
Name 3 gastrointestinal causes of acute abdominal pain
- Appendicitis
- Biliary disease
- Pancreatitis
- Diverticular disease
- PUD
Name 3 genitourinary causes for acute abdominal pain
- UTI
- Nephrolithiasis
- Ovarian torsion
- Ruptured ovarian cyst
- PID
Name 6 common causes of abdominal distension
Fluid, fat, faeces, flatus, foetus, filthy big tumour, organomegaly
What is the significance of rigidity?
Rigidity is the constant involuntary contraction of abdominal muscles in response to an injury.
It is an important sign of peritonism.
Hyperresonant percussion note across a distended abdomen indicates which cause of distension?
Hyperresonance = air
What is the most common cause of hyperactive bowel sounds? What are 2 other causes/DDx?
Most common: bowel obstruction
DDx: gastroenteritis, IBD
What do ‘tinkling’ bowel sounds indicate?
Bowel obstruction
Name 2 causes of absent bowel sounds
- Ileus
- Later stages of intestinal obstruction
Give 2 differentials for each of the following causes of RUQ pain:
- Liver
- Biliary
- Other
LIVER: infectious (acute viral hepatitis, liver abscess), non-infectious (CHF/hepatic congestion, non-infectious hepatitis e.g. alcohol & medication, Budd-Chiari syndrome)
BILIARY: infectious (ascending cholangitis, acute cholecystitis), non-infectious (gallstones, choledocholithiasis)
OTHER: RLL pneumonia, sub diaphragmatic abscess
Name 3 causes of acute abdominal pain that is DIFFUSE / POORLY-LOCALISED
- IBD
- Spontaneous bacterial peritonitis
- Secondary peritonitis (e.g. bowel perforation)
- DKA
What type of abdominal pathology causes pain to radiate to the back?
Pyelonephritis
What type of abdominal pathology causes pain to radiate down the groin?
Nephrolithiasis
What type of abdominal pathology causes pain to radiate to the shoulder?
Hepatic & biliary pathology
What type of abdominal pathology causes pain to radiate straight backwards?
- AAA
- Pancreatitis
https://www.youtube.com/watch?v=_PDOXlVGeuY
Name the 2 layers of peritoneum and the types of pain they cause
PARIETAL PERITONEUM: lines the abdominal cavity and causes SOMATIC (well-localised) pain
VISCERAL PERITONEUM: lines the abdominal organs and causes VISCERAL (poorly-localised, can cause referred) pain
Where does foregut, midgut, and hindgut pain refer?
FOREGUT: epigastric
MIDGUT: umbilical
HINDGUT: suprapubic
What is the most common type of peritonitis?
Secondary peritonitis; other structures are infected, causing the infective organism to be introduced to the peritoneum
Name 4 INFLAMMATORY causes of secondary peritonitis
- ITIS: appendicitis, diverticulitis, acute pancreatitis, cholecystitis
- Small bowel ischaemia
Name 3 PERFORATIVE causes of secondary peritonitis
- PUD perforation
- Appendicitis
- Diverticulitis
Use the ‘I GET SMASHED’ pneumonic to list the causes of pancreatitis
I - idiopathic
G - gallstones
E - ethanol
T - trauma (post-ERCP)
S - steroids M - mumps virus A - autoimmune S - scorpion stings / spider bites H - high cholesterol / calcium levels E - ERCP D - drugs (azathioprine, diuretics)
Outline the pathophysiology of gallstones leading to acute pancreatitis
- Stone lodged in distal common bile duct, blocking the ampulla of Vater
- Increased pressure in the pancreatic duct / bile reflux into the pancreas
- Inflammation & injury to pancreas
List 4 common symptoms of acute pancreatitis
- Rapid onset of epigastric pain (may radiate to the back)
- Nause/vomiting
- Anorexia
- Malaise
The pain of acute pancreatitis may be relieved by what positional changes?
Leaning forward or sitting up
Name 2 scoring systems used to evaluate the SEVERITY of pancreatitis
(note that this is separate from the PAIN severity)
- APACHE
- Modified Glasgow score (PANCREAS: pO2, age, WCC, Ca2+, raised urea, elevated LFTs, albumin, sugar)
- Atlants
Name the 4 components of SIRS (TTTW)
Temperature/Fever (>38 or <36)
Tachycardia (>90)
Tachypnoea (RR>20)
WCC (>11 or <4)
Presence of 2 or more features indicates SIRS
What is the progression of illness when someone has SIRS?
Organ dysfunction –> organ failure –> multiple organ failure (MOF) –> Death
Describe the presentation of acute pancreatitis
- Burning epigastric pain (may radiate to the back, worsen with food and when supine)
- NV
- Fever
- Possible pulmonary complications (chest pain, dyspnoea)
List 3 of the most common causes of acute pancreatitis
- Alcohol
- Gallstones
- ERCP
Describe the Atlanta scoring system for the classification of acute pancreatitis
MILD: no local complications, no organ failure
MODERATE: transient organ failure (<48 hours), +/- local complications
SEVERE: persistent organ failure (>48 hours)
- local complications = acute peripancreatic fluid accumulation, pancreatic pseudocyst, acute necrotic collection, pleural effusion
- organ failure = failure of 3 main organs (cardio, respiratory, renal) + OTHER organ systems
What is shock?
Tissue hypo perfusion
Name the 6 types of shock
- Hypovolemic
- Septic
- Haemorrhagic
- Anaphylactic
- Neurogenic
- Cardiogenic
Metabolic acidosis + abdominal pain should be treated as WHAT CONDITION until proven otherwise?
Bowel ischaemia
Which laboratory studies may be deranged in a patient with small bowel obstruction? Explain why.
Hypokalaemia - due to vomiting
Hypo/hypernatremia - due to vomiting (retention of sodium and discharge of potassium can occur in the later stages of obstruction, leading to HYPERnatremia)
High urea & creatinine - dehydration, kidney hypoperfusion, AKI
Which anatomical feature distinguishes the small intestine on abdominal X-ray?
Valvulae conniventes / plicae circularis
What is the most common cause of small bowel obstruction?
Adhesions (related to previous surgical procedures)
What are the 3 most common causes of small bowel obstruction? (ABC)
Adhesions, hernias, neoplasms
ABC = adhesions, bulge/hernia, cancer
Use the acronym SHAVIING to list the causes of small bowel obstruction
S - strictures H - hernias A - adhesions V - volvulus I - infection (e.g. TB, parasites) I - intussusception / IBD N - neoplasm G - gallstones
Describe the clinical presentation of small bowel obstruction
Abdominal pain in the umbilical area, colicky in nature
Nausea / Vomiting (more severe in proximal SBO)
Constipation/obstipation
Abdominal distension
Possibly: fever, tachycardia
Describe the clinical presentation of small bowel obstruction
Abdominal pain in the umbilical area, colicky in nature
Nausea / Vomiting (more severe in proximal SBO)
Constipation/obstipation
Abdominal distension
Possibly: fever, tachycardia
Passing wind and stool 6-12 hours within symptom onset suggests what type of SBO?
PARTIAL small bowel obstruction (as opposed to complete)
Which investigation is used to diagnose a SBO?
Abdominal X-ray (supine and erect)
What features must be present on the abdominal X-ray in order for a diagnosis of SBO?
- Dilated bowel loops with air-fluid levels !
- Proximal bowel dilation w/distal bowel collapse
- Gasless abdomen
Outline the NON-SURGICAL approach to a SBO. How long are these procedures utilised for?
72 hours:
- NG tube decompression
- Fluid resus
- Analgesia
- Anti-emetics
Continued clinical assessment. If symptoms of SBO persist, surgery is indicated
How are adhesive vs. nonadhesive causes of SBO diagnosed?
ADHESIVE SBO is often a diagnosis of exclusion, as adhesions cannot be visualised by imaging. A past surgical history + absence of other known causes is suggestive of adhesions.
NON-ADHESIVE causes of SBO can usually be diagnosed with imaging studies
When is immediate surgical management indicated for SBO?
- Signs of bowel compromise (ischaemia, perforation, necrosis) which may manifest as systemic signs (e.g. fever, leukocytosis, tachycardia, metabolic acidosis, SIRS)
- Surgically correctable cause of SBO (except adhesions)
When is immediate surgical management indicated for SBO?
- Signs of bowel compromise (ischaemia, perforation, necrosis) which may manifest as systemic signs (e.g. fever, leukocytosis, tachycardia, metabolic acidosis, SIRS)
- Surgically correctable cause of SBO (except adhesions)
During shock, blood redistribution occurs to protect the brain and heart. What are 2 clinical manifestations of redistribution?
- Cool, clammy peripheries (blood diverted away from skin)
- Low urine output (blood diverted away from kidneys)
Shock exceeding compensation is an emergency. List 4 clinical manifestations of this.
- Tachycardia
- Hypotension
- Cool, clammy peripheries
- Low urine output
(septic shock will also present with fever)
Describe the supportive management approach for an acute abdomen
- ESCALATE: MET team, ICU, transfer
- AIRWAY/BREATHING: sigh-flow O2 15/L per hour
- CIRCULATION: 2x large-bore IV cannula (fluid + Abx if needed)
Describe the 7 interventions that should be performed WITHIN 3 HOURS in someone who is suffering from septic shock (https://www.sccm.org)
- Measure LACTATE level
- Blood tests (to be cultured)
- Broad-spectrum Abx (if needed - often will be)
- FLUIDS: 30mL/kg of IV crystalloid fluids for hypotension or lactate >4mmol/L
Critical care territory / less relevant for med students:
- Vasopressors (e.g. noradrenaline)
- If persistent hypotension: more detailed assessment of volume status
- Re-measure lactate if initial lactate was elevated
Which other systems would you consider reviewing in someone who presents with abdominal pain/abdominal pathology?
- GIT
- Gynaecological
- Urological
- Vascular
- MSK
Pyramid of abdominal examination findings in the ACUTE setting
- Soft, non-tender: normal
- Soft, tender: abnormal
- Tender, guarding: local peritonitis
- Tender, rigidity: generalised peritonitis
Increasing levels of abnormality/pathology which will affect your management
What is the pathophysiology behind rebound/percussion tenderness?
Peritonitis –> inflammation of the peritoneum –> percussion or letting go of the abdominal wall quickly –> irritates peritoneum –> pain
Sign of peritonitis
Localised vs. generalised peritonitis?
Localised = signs of peritonism (rigidity, guarding, tenderness) in one section/quadrant of the abdomen
Generalised = signs of peritonism across the entire abdomen
How can a small bowel obstruction lead to bowel ischaemia and infarction?
- Small bowel obstruction
- Accumulation of GI contents (gas, fluid, food) proximal to the obstruction
- Continued accumulation over time and worsening distension proximal to the obstruction
- Increased luminal size & pressure
- Pressure compresses intestinal arteries
- Decreased bowel perfusion –> ischaemia, infarction, necrosis
How can a small bowel obstruction lead to dehydration?
GI contents (salts, active solutes) osmotically draw water out of the vascular system and into the GI tract –> lower effective arterial blood volume –> dehydration
Also they’re probably not eating or drinking much
How does a small bowel obstruction lead to pain?
- Small bowel obstruction
- Accumulation of GI contents (gas, fluid, food) proximal to the obstruction
- Continued accumulation over time and worsening distension proximal to the obstruction
- Continued peristalsis pushes against GI contents
- Colicky abdominal pain, tenderness, guarding, rigidity
Describe the physical exam findings that may be present in someone with acute pancreatitis
- Inspection: possible jaundice, skin changes (e.g. Cullen’s sign, Grey Turner’s sign)
- Palpation: epigastric tenderness, rigidity, distension, guarding
- Auscultation: reduced bowel sounds
VITALS: signs of shock (tachycardia, tachypnoea, hypotension, oliguria)
Which lab tests would you order for someone with suspected acute pancreatitis and WHY?
- CBE: leukocytosis supports the diagnosis
- Iron studies: raised haematocrit indicates haemoconcentration due to third-spacing and/or inadequate fluid resuscitation
- LIPASE: 3x normal limit is diagnostic for acute pancreatitis
- AMYLASE: will rise, but is a bit less sensitive and specific for acute pancreatitis and has a short half-life
- LFTs: may be deranged due to the disease process, but can also indicate aetiology (raised ALP, GGT suggests biliary cause)
Why are calcium levels important in acute pancreatitis?
HYPERcalcemia can cause acute pancreatitis, which THEN causes HYPOcalcemia
Acute pancreatitis can be diagnosed when 2 out of 3 criteria are met. Name these criteria.
- Consistent clinical findings
- Lipase 3x normal
- Supportive findings on imaging
Name the 4 steps taken to evaluating and treating acute pancreatitis
- Evaluate SEVERITY (several scoring systems exist)
- Initiate acute treatment
- Assess local complications
- Assess aetiology
Describe the acute treatment for acute pancreatitis
- Fluid resuscitation w/isotonic crystalloid!!! (fluid replacement is the most important measure)
- Analgesia
- Nutritional support
- Anti-emetics
(if gallstone pancreatitis –> cholecystectomy)
https://www.youtube.com/watch?v=RvYS2RFz4LU
Name 4 local complications of acute pancreatitis
- Pseudocyst
- Abdominal compartment syndrome
- Bacterial superinfection of necrotic tissue
- Pleural effusion
Name 4 SYSTEMIC complications of acute pancreatitis
- SHOCK
- SIRS, DIC
- Hypocalcemia
- Respiratory failure, ARDS
- Paralytic ileus
Gallstones block which structure to cause acute pancreatitis?
Sphincter of odd / hepatopancreatic duct / ampulla of Vater
How does acute pancreatitis lead to SIRS?
Acute pancreatitis –> blockage of pancreatic secretions –> increased pressure –>
tissue ischaemia due to compression of pancreatic blood vessels + activation of enzymes
–> necrosis, digestion of pancreatic tissue –> inflammation –> SIRS
What is the most useful initial test in someone with acute pancreatitis?
Ultrasound
Describe the ultrasound findings of a patient with gallstones
Acoustic shadowing
Dilation of the biliary tract
Use the acronym PANCREAS to list the treatment of acute pancreatitis
P - perfusion (FLUID REPLACEMENT w/electrolytes)
A - analgesia
N - nutritional support
C - clinical observation
R - radiology (imaging)
E - ERCP for gallstones
A - antibiotics (if there is infected necrosis)
S - surgery/cholecystectomy for biliary pancreatitis
What is metoclopramide, and how does it work?
An anti-emetic.
It is a dopamine antagonist and has 2 actions:
1. Dopamine antagonist in the chemoreceptor trigger zone (medulla), inhibiting the chemicals that trigger NV
- Dopamine antagonist in the LOS, increasing tone and antral + SI contractions
What is third-spacing and why does it occur in acute pancreatitis? What are the consequences?
DEFINITION: Third-spacing is the movement of intravascular fluid to interstitial spaces. May manifest as raised haematocrit.
Occurs as a result of:
(a) Altered hydrostatic/oncotic pressure
(b) Inflammation/injury to the epithelium.
Can result in hypovolemic shock.
Which crystalloid solution is preferred for acute pancreatitis?
Lactated Ringer’s / Sodium lactate / Hartmann’s solution
Contains electrolytes
Ultrasound findings of pancreatitis
- Pancreatic oedema: indistinct pancreatic margins
- Peripancreatic fluid buildup: area corresponding to pancreas will be hypoechogenic /dark
- Maybe evidence of necrosis, abscesses, pseudocysts
Anti-emetics
.
Name 7 parameters that can be used to assess severity of hypovolaemic shock
- Pulse (tachycardia)
- Pulse pressure (weak)
- Systolic BP (hypotension)
- Respiratory rate (tachypnoea)
- Capillary refill
- Cool, clammy skin
- Mental status
- Urine output
Name 4 differentials for RUQ pain
- Biliary colic
- Choledocholithiasis
- Acute cholecystitis
- Acute cholangitis
- R LL pneumonia
Name 4 differentials for EPIGASTRIC pain
- PUD
- Acute pancreatitis
- GORD
- MI
- Gastritis
Name 4 differentials for LUQ pain
- PUD
- Splenic infarct
- Splenic abscess
- Splenic rupture
- LLL pneumonia
Name 3 differentials for flank pain
- Pyelonephritis
- Nephrolithiasis
- Perinephric abscess
Name 5 differentials for umbilical pain
- Early appendicitis
- Gastroenteritis
- PUD
- Bowel obstruction
- Ruptured AAA
- Mesenteric ischaemia
Name 5 differentials for RIF pain
- Appendicitis
- Ovarian torsion
- Testicular torsion
- Ectopic pregnancy
- Ruptured ovarian cyst
Name 5 differentials for LIF pain
- Diverticulitis
- Ovarian torsion
- Testicular torsion
- Ectopic pregnancy
- Ruptured ovarian cyst
Name 3 differentials for suprapubic pain
- UTI
- PID
- Ectopic pregnancy
Why is urinary output measured in acute abdo?
How much urine output is desirable?
Assess hydration status
0.5mL/kg/hour
Name 4 causes of SBO
- Adhesions
- Hernias
- Volvulus
- Intussusception
Name 4 causes of SBO
- Adhesions
- Hernias
- Volvulus
- Intussusception
- Strictures
What is Courvoisier’s law?
In a patient with painless jaundice and an enlarged gallbladder (or RUQ mass), the cause is unlikely to be gallstones and therefore presumes the cause to be an obstructing pancreatic or biliary neoplasm until proven otherwise
What is Murphy’s sign?
Murphy’s sign is elicited in patients with acute cholecystitis by asking the patient to take in and hold a deep breath while palpating the right subcostal area. If pain occurs on inspiration, when the inflamed gallbladder comes into contact with the examiner’s hand, Murphy’s sign is positive.
State the definitions for cholelithiasis, choledocholithiasis, acute cholecystitis, and ascending/acute cholangitis
Cholelithiasis: gallstones in the gallbladder
Choledocholithiasis: gallstones in the common bile duct
Acute cholecystitis: acute inflammation of the gallbladder
Ascending/acute cholangitis: bacterial infection of the biliary tract
State the CLINICAL MANIFESTATIONS of cholelithiasis, choledocholithiasis, acute cholecystitis, and ascending/acute cholangitis
CHOLELITHIASIS: symptomatic biliary colic <6 hours (RUQ pain), but usually asymptomatic
CHOLEDOCHOLITHIASIS: biliary colic <6 hours (RUQ pain), possible jaundice
ACUTE CHOLECYSTITIS: RUQ pain, positive Murphy’s sign, fever
ASCENDING CHOLANGITIS: Charcot’s triad (RUQ pain, fever, jaundice), Reynold’s pentad (Charcot’s triad PLUS hypotension & mental status changes)
Which biliary tract disorders are more likely to have abnormal LFTs? Name the markers which could be raised.
Choledocholithiasis: elevated GGT, ALP, AST, and ALT
Ascending cholangitis: elevated ALP, AST, ALT, and total bilirubin
Describe the pain of acute pancreatitis
- Epigastric
- Burning
- Sudden onset
- Worsens with food and when supine
- Improves on sitting up or leaning forward
Describe the components of the modified Glasgow score (PANCREAS)
Modified Glasgow Score is used for assessing the severity of acute pancreatitis. The components are:
P - (spO2) A - age >55 years N - neutrophils (WCC) >15 C - calcium <2mmol/L R - raised urea >16mmol/L E - LDH >600 A - albumin <32 S - sugar (BGL >10)
3 or more points (1 point each): severe pancreatitis
Outline the initial management of acute pancreatitis
- IV FLUIDS: 250-500mL of isotonic crystalloid solution
- Analgesia: IV morphine or fentanyl
- Anti-emetics if needed
- Oral intake may not need to be ceased if the patient only has mild pancreatitis and is tolerating PO intake
State the following information for metoclopramide:
- Drug class
- Route of administration
- Precautions
- Side effects
- Drug class: dopamine ANTAGONIST
- Route of administration: PO, IM, IV
- Precautions: avoid in patients <20 years, Parkinson’s patients, and when stimulation of GIT is dangerous (e.g. bowel perforation, obstruction)
- Side effects: EPSE (tardive dyskinesia, acute dystonic reaction), akathisia, drowsiness
3 complications of bowel obstruction
- Perforation
- Bowel ischaemia
- Sepsis (either from necrotic cells or bacterial dissemination d.t. perforation)
Most common cause of death in acute pancreatitis?
Acute respiratory distress syndrome
Mechanism of ARDS in acute pancreatitis
Acute pancreatitis –> circulating pancreatic enzymes –> increase in pulmonary vasculature permeability –> transudation of fluid into alveolar space
How does acute pancreatitis lead to diminished bowel sounds?
Acute pancreatitis –> autodigestion of pancreatic tissue –> necrosis –> inflammation / SIRS –> irritation of intestines –> ileus
How does SBO lead to SEPSIS?
SBO –> bowel distension –> compression of intestinal lymphatics & veins –> bowel wall oedema –> compression of intestinal arterioles & capillaries –> ischaemia –> increased permeability –> translocation of intraluminal bacteria –> SEPSIS
How does SBO lead to peritonitis?
SBO –> bowel distension –> compression of intestinal lymphatics & veins –> bowel wall oedema –> compression of intestinal arterioles & capillaries –> ischaemia –> necrosis –> perforation of bowel wall –> PERITONITIS
The presence of which 3 clinical features precludes oral intake in acute pancreatitis?
- Ileus
- Nausea
- Vomiting
Simple vs. complicated vs. red flag bowel obstruction
SIMPLE: no evidence of complications (e.g. bowel ischaemia, bowel perforation, or red flag symptoms)
COMPLICATED: strangulation, ischaemia, necrosis
RED FLAG: pain out of proportion, peritoneal signs, SIRS, haemodynamic instability, lab abnormalities (++leukocytosis, metabolic acidosis, lactate)
What is the 3-6-9 rule for abdominal X-rays?
Transverse diameter greater than the following indicates dilation:
- Small bowel >3cm
- Large bowel >6cm
- Caecum >9cm
Results of the following investigations when complicated SBO is present:
- CBE
- Iron studies
- EUC
- Lactate
- ABG
- CBE: leukocytosis (e.g. due to SIRS)
- Iron studies: raised haematocrit (third-spacing)
- EUC: hyponatremia, hypokalaemia, hypochloraemia d.t. vomiting. Hyperkalemia if there is bowel ischaemia.
- Lactate: raised (bowel ischaemia)
- ABG: metabolic acidosis (bowel ischaemia)