Acute Abdomen & Surgical Emergencies

 

• Background

  Definition

  Acute (<1 week), new onset, abdominal pain.

  Causes

  • Inflammation: appendicitis, diverticulitis, cholecystitis, gastroenteritis, salpingitis (PID), inflammatory bowel disease, pyelonephritis.
  • Rupture/perforation: spleen, abdominal aortic aneurysm, peptic ulcer, appendix, bowel, gallbladder, ectopic pregnancy, ovarian cyst.
  • Bowel obstruction.
  • Bowel ischaemia.
  • Torsion and strangulation: strangulated hernia, ovarian cyst torsion, testicular torsion.
  • Chest: lower lobe pneumonia, inferior MI.
  • Others: renal colic, endometriosis, adhesions.

• Signs and symptoms

  Visceral (organ) pain:

  • Poorly localised.
  • In the context of an obstructed viscus or lumen, may cause colic as waves of peristalsis push against obstruction.
  • Foregut structures – from lower ⅓ of oesophagus to ampulla of Vater – cause epigastric pain.
  • Midgut structures – up to ⅔ of transverse colon – cause umbilical pain.
  • Hindgut structures – up to proximal rectum – cause suprapubic pain.

  Parietal pain (peritonitis):

  • Somatic innervation so better localised.
  • Patient is lying still, as pain exacerbated by movement.
  • Guarding: involuntary contraction of abdo muscles when palpated.
  • Rigidity: contraction of abdo muscles at rest.
  • Rebound tenderness.
  • If generalised, leads to absent bowel sounds and shock (↑RR, ↑HR, ↓BP).

  Rigors suggest:

  • Cholangitis
  • Pyelonephritis
  • Intra-abdominal abscess.

• Initial management

  General approach

  At least consider all of these:

  • Tests: urine dip, bloods, ABG.
  • Bloods: at least FBC and U&E. Consider coag, group and save, amylase, LFT, βhCG, CRP, lactate.
  • Imaging: US, erect CXR, AXR, CT abdo.
  • Meds: analgesia, antibiotics, IV fluids, nil by mouth (NBM).

  In young women with lower abdo pain, consider US and/or exploratory laparoscopy before CT abdo, due to the radiation risk (including to fetus) and because CT is less useful for many gynae problems.

  In unstable patients with an acute abdomen, always consider ruptured AAA, acute pancreatitis, and ruptured ectopic.

  Right iliac fossa pain

  • Urine dip.
  • Bloods: FBC, U&E, CRP
  • βhCG and US if female.
  • IVT and NBM if appendicitis suspected.

  Left iliac fossa pain

  • US and βhCG in women.
  • Suspect diverticulitis if older → antibiotics, IV fluids, probably CT.

  Right upper quadrant pain

  • Key history questions: previous gallstones or US.
  • Bloods: FBC, U&E, LFTs, amylase.
  • US usually needed, looking for gallstones or CBD dilation.
  • MRCP if US shows dilated CBD and ↑LFTs.

  Epigastric pain

  • Key history questions: previous OGD, peptic ulcer, gallstones, or pancreatitis.
  • Bloods: FBC, U&E, LFTs, amylase.
  • Erect CXR.
  • Pancreatitis risk score: ABG, LDH, AST, Ca2+, glucose.

  Generalised abdo pain

  • Key history questions: bowel habit, features of obstruction, perforation, and ischaemia.
  • Bloods: FBC, U&E, LFT, amylase, CRP, lactate. ABG if suspected lactic acidosis.
  • Urinalysis
  • CXR and AXR.
  • Analgesia, NBM, IV fluids.

• Lower GI bleed

  Causes

  • Diverticular disease.
  • Colorectal carcinoma (5%) or polyps, especially rectal. May also occur post removal e.g. polypectomy.
  • Vascular: haemorrhoids, angiodysplasia.
  • Anal fissure
  • IBD, usually UC.
  • Ischaemic colitis.
  • Gastroenteritis (infective colitis): Campylobacter, Salmonella, Shigella, E. coli.
  • Radiation enteropathy: usually presents within 1 year of treatment.

  Signs and symptoms

  • Haematochezia: fresh red blood PR. Note that 15% is due to an upper GI cause.
  • Passage of blood may occur with or without passage of stool. If they co-occur, the blood may be mixed into the stool or sit on the outside.
  • Fever in IBD or gastroenteritis.
  • Weight loss in cancer.
  • Abdominal pain, depending on cause.

  Management

  Initial management and investigations:

  • ABC including transfusion if needed.
  • Bloods, including FBC, coag, cross-match.
  • If unstable, CT angiography of abdomen-pelvis. Upper GI endoscopy if no bleed found.
  • If stable, consider inpatient or outpatient lower GI endoscopy (based on risk as per Oakland score).

  Definitive management:

  • Colonoscopy for localisation of source and haemostasis, using adrenaline, thermal coagulation, and/or clipping. Done urgently only if patient unstable.
  • Mesenteric angiography and embolisation by interventional radiology is an alternative to colonoscopy if bleed seen on CTA.
  • Surgery if other measures fail.

• Nasogastric tube placement

  Indications

  • Nasogastric decompression e.g. during bowel obstruction.
  • Feeding
  • Giving drugs.

  Contraindications

  • Basal skull fracture
  • Severe facial or nasal trauma.
  • Caution: oesophageal varices or stricture, coagulopathy.

  Procedures

  1. Check indication, check for contraindications, and gain consent.
  2. Check length needed with NEX (nose to ear to xiphoid) method. Typical length is around 55 cm.
  3. Pass tube into nostril, advancing forward. To help its passage, ask patient to swallow (e.g. water) and/or tilt chin down. Lubricant not needed and may cause cough, but wetting with water may help.
  4. Check placement. 1st line test is pH paper (should be <5.5), 2nd line is CXR. If sending for CXR, leave guidewire in place in case it needs to be moved (the tube is radio-opaque anyway). On CXR, tube tip should bisect the carina, cross the diaphragm in the midline, and the tip should be visible beneath the diaphragm (ideally on the left, as if it's on the right it may be in the duodenum).
  5. If 3 attempts unsuccessful, should be done by XR guidance.

  Complications

  • Local trauma e.g. nosebleed.
  • Tube into lung and aspiration pneumonitis.
  • Oesophagitis
  • Perforation
  • Vocal cord paralysis.

• Complications of abdominal surgery

  Immediate (<24 hrs)

  • Intubation complications e.g. mouth or teeth trauma.
  • Anaesthetic complications e.g. anaphylaxis.
  • Infection
  • Primary haemorrhage during op (vessel trauma) or reactionary haemorrhage post-op as BP rises and poorly ligated vessels are re-perfused.
  • Damage to surrounding structures.

  Early (<1 week)

  Fever:

  • Think the 7Cs: Cut (wound), Chest, Catheter, Cannula, Central line, Collection, Calves (DVT).
  • Early infections (first few days) more likely to be UTI or chest, while later infections are more likely to be wound site (~1 week) or collections (1-4 weeks).

  Respiratory:

  • Pneumonia and/or lobar collapse (atelectasis), secondary to splinting (shallow breathing due to pain) and/or mucous plugs. Atelectasis may present with fever, usually on day 1.
  • DVT and PE.

  GI/GU:

  • Paralytic ileus
  • Reduced urine output: retention, blocked catheter, AKI, pain (e.g. post-hernia), BPH, drugs (opioids, anticholinergics).
  • UTI

  Others:

  • Wound dehiscence.
  • (Secondary) haemorrhage: infective erosion through vessel wall.

  Late (<1 month)

  Often specific to operation.

  Long-term

  • Disease recurrence.
  • Often specific to operation.

  Approach to post op sick patient

  Always think about the following common and serious complications. It's SIMPLE:

  • Sepsis
  • Ileus
  • MI
  • Pneumonia
  • Anastomotic Leak.
  • Embolus: PE or DVT.