Makindo Medical Notes

Related Subjects:Acute Cholecystitis |Acute Appendicitis |Chronic Peritonitis |Abdominal Aortic Aneurysm |Ectopic Pregnancy |Acute Cholangitis |Acute Abdominal Pain/Peritonitis |Assessing Abdominal Pain |Penetrating Abdominal Trauma |Acute Pancreatitis |Acute Diverticulitis

Pain may be absent in elderly, those on steroids, diabetics and may be difficult to assess in the very frail. Are they moribund in extremis then ABC and get help fast and in meantime get IV access, Oxygen, IV Crystalloids, Analgesia and send off bloods including lactate, FBC, U&E, Amylase, cross match if haemorrhage a concern. If bleeding and shocked get in two lines and consider O negative blood. If sepsis then IV antibiotics and fluids.

Acute Abdomen

• Sudden onset of severe abdominal pain of less than 24 hours duration
• Can be a marker of severe potentially lethal pathology
• Needs expert assessment and rapid escalation to decide if surgery needed

Tends to be divided into its embryological origins and their pain radiation

• Foregut pain: Epigastrium
• Midgut pain: Peri umbilicus
• Hindgut pain : Below umbilicus

Background Notes

• Parietal peritoneum is richly innervated with sensory fibres and so any inflammation causes a localised reaction with pain, tenderness, guarding and rigidity
• The best example is appendicitis - the appendix is a midgut structure so causes periumbilical pain.
• When the peritoneum becomes inflamed the pain localises classically to McBurney's point
• Hernial orifices must always be examined to exclude inguinal and femoral and other hernias

Causes of acute abdominal pain

More comprehensive list of Causes of acute abdominal pain

• Surgical causes
  • Acute Appendicitis 30%
  • Acute Cholecystitis 10%
  • Small bowel obstruction 5%
  • Perforated peptic ulcer 3%
  • Pancreatitis 3%
  • Diverticular disease 2%.
  • Biliary Colic, Any Perforation, Acute pancreatitis
  • Peptic ulcer disease, Ruptured Abdominal aortic aneurysm
  • Large bowel perforation, Diverticulitis
  • Bowel obstruction, Urinary retention
  • Ureteric colic, Testicular torsion
• Medical causes of Acute abdominal pain
  • Myocardial infarction, Acute Pneumonia, Pulmonary Embolism
  • Acute Hepatitis, Diabetic Ketoacidosis
  • Familial Mediterranean fever, Variegate Porphyria
  • Acute intermittent porphyria, Hereditary Coproporphyria
  • Tabes Dorsalis, Herpes zoster (Shingles)
  • Irritable bowel syndrome
• Gynaecological
  • Ectopic pregnancy
  • Pelvic inflammatory disease
  • Mittelschmerz
  • Endometriosis
  • Ovarian cyst
• Mixed medical/Surgical - occasionally needing surgery
  • Acute Pancreatitis (mixed medical/surgical), Peptic ulcer disease
  • Diverticulitis, Ulcerative colitis, Crohn's disease
• Cardiac
  • Myocardial infarction (often inferior)
  • Myocarditis, Pericarditis
• Metabolic
  • Variegate Porphyria, Acute intermittent porphyria
  • Hereditary Coproporphyria
  • Diabetic ketoacidosis, Lactic acidosis
  • Familial Mediterranean fever
• Pulmonary
  • Acute Pneumonia/pneumonitis
  • Pulmonary Embolism, Spontaneous pneumothorax
  • Large pleural effusion/pleurisy
• Hepatic
  • Acute Hepatitis, Liver abscess, Budd-Chiari syndrome
• Neurological
  • Syphilis and Tabes Dorsalis
  • Herpes zoster (Shingles) - usually dermatomal and unilateral
  • Abdominal migraine
• Functional
  • Irritable bowel syndrome

Differentials

Diagnostic Clues

Acute Abdomen

Surgical Differential and Clues

Investigations

• FBC, U&E, LFTs, CRP, Calcium, Blood glucose
• Pregnancy test: important to exclude pregnancy and ectopic pregnancy
• Amylase: Any reading x3 greater than the upper limit is diagnostic of pancreatitis. False positives with perforated bowel, ectopic pregnancy, or Diabetic Ketoacidosis.
• Urine dipstick: Blood suggests stones, Acute pyelonephritis, possible tumour
• Sickle tests: do in all at risk patients
• ABG if bleeding or septic. Lactate rapid haemoglobin.
• Group & save (G&S) if the patient is likely to need surgery soon or there is haemorrhage
• Blood cultures if considering infection as a potential diagnosis
• AXR: helpful really when there is perforation or obstruction. Does not help with biliary disease or peptic ulcer disease or appendicitis
• CXR: see causes of free air below - perforation. Can also help identify pneumonia and other lung pathology
• Contrast Radiology: contrast can be given PO/NG or PR and is usually water soluble. It can help diagnose perforation or obstruction.
• ECG: Look for ST elevation as acute MI can masquerade as abdominal pain
• CT Abdomen usually with oral contrast is usually most useful test now to help identify the issue and its cause. Rectal contrast is given for large bowel obstruction. It can help determine mechanical from non mechanical obstruction.
• Contrast enhanced CT can help show free gas in the abdomen and ischaemic bowel, bowel obstruction, and inflammatory conditions such as appendicitis or diverticulitis and pancreatic necrosis.
• CT angiography: for Mesenteric Ischemia and for management of lower Gastrointestinal haemorrhage
• Urinary Porphobilinogen: for acute porphyria
• Laparoscopy: can help surgical decision making especially in older patients and young women

Causes of Free sub-diaphragmatic gas on AXR

• Perforation of an intraabdominal viscus
• Gas forming infection
• Pleuroperitoneal fistula
• Iatrogenic - laparoscopy and laparotomy
• Gas introduced per vaginam post partum
• Interposition of bowel between liver and diaphragm

Specific Diagnostic Management Issues

Acute Management

• Stabilise the patient. ABCS Oxygen and IV access. Keep Nil by mouth/ Nil PO
• Start IV crystalloid at least 3L/day but may need more than this if dry.
• Urinary catheter and close observation of EWS score
• Nasogastric tube if there is obstruction
• Central venous pressure monitoring may be needed in HDU/ITU setting
• Check, Replace and Correct electrolytes.
• Variable rate Insulin infusion if diabetic and high sugars
• Consider IV antibiotics and Group and save or cross match as needed
• Urgent Senior surgical review and anaesthetic if surgery considered
• Question will often be on need for CT and urgency of any laparotomy
• DVT prophylaxis is advised

Surgical management is key

• Delays only to allow resuscitation and achieving volume status
• Antibiotic cover e.g. Tazocin or Gentamicin or Amoxycillin/Metronidazole
• Removal of infarcted tissue or perforated bowel
• Repair of any viscus perforation
• Removal of infective foci or drainage
• Peritoneal lavage is performed.