09 / Complications
What can go wrong
Organized by when they strike. For each: how it presents, the clues on the chart, and the concept that makes it make sense. Linked from every relevant procedure.
Postoperative bleedingearly
Tachycardia first, hypotension late; falling urine output; a distending abdomen or rising drain output.
Clues: HR trending up across serial observations · Narrowing pulse pressure · Fresh blood in a drain · Falling hemoglobin
The concept: Young patients compensate until they suddenly do not, the trend matters far more than any single reading. Tachycardia after surgery is bleeding until proven otherwise.
Laparoscopic cholecystectomyOpen appendectomySmall bowel resection & anastomosis
Anastomotic leakearly
Day 3–7: tachycardia, fever, abdominal pain, ileus that fails to resolve, or subtle deterioration that 'doesn't add up'.
Clues: Persistent tachycardia after day 3 · New atrial fibrillation · Rising inflammatory markers · Feculent or bilious drain fluid
The concept: The most feared general-surgical complication. Unexplained tachycardia or new AF in a bowel-anastomosis patient is a leak until excluded.
Bile leakearly
Right upper quadrant pain, fever, and bilious drain output, or a patient who is simply failing to thrive after cholecystectomy.
Clues: Bilious drain fluid · RUQ pain and fever after lap chole · Persistently elevated bilirubin
The concept: Usually a cystic-duct stump or duct-of-Luschka leak. The lesson upstream is identification before division: the Critical View exists because this complication does.
Postoperative ileusearly
Distension, absent flatus, intolerance of diet, and quiet bowel sounds in the days after abdominal surgery.
Clues: No flatus by expected recovery · Distension with diffuse discomfort · Bilious vomiting or high NG output
The concept: Some ileus is physiologic after handling bowel. The task is separating expected slowness from mechanical obstruction or a driver like a leak, electrolyte derangement, or opioids.
Atelectasis & pulmonary complicationsearly
Low-grade fever and mild desaturation in the first 48 hours, especially after upper-abdominal incisions.
Clues: Day 1-2 fever · Basal crackles and reduced air entry · Shallow breathing from poorly controlled pain
The concept: Pain that prevents deep breathing collapses lung bases. Analgesia, sitting up, and breathing exercises are respiratory treatments here.
Surgical-site infectionlate
Wound erythema, warmth, discharge, and pain out of proportion, typically from postoperative day 4–7.
Clues: Fever pattern starting around day 4-5 · Spreading wound erythema · Purulent discharge
The concept: Fever timing narrows the differential: day 1–2 favours atelectasis and the respiratory tract; day 3–5 urinary and line sources; day 4–7 the wound itself.
Open appendectomySmall bowel resection & anastomosisLaparoscopic cholecystectomy
Intra-abdominal abscesslate
Swinging fevers, malaise, and localized pain from day 5 onward, classically after perforated appendicitis.
Clues: Spiking (swinging) fever curve · Rising CRP after an initial fall · Diarrhoea with a pelvic collection
The concept: A walled-off collection behaves differently from diffuse sepsis: the fever swings, and drainage, not just antibiotics, is the definitive treatment.
Venous thromboembolismlate
Unilateral leg swelling, or sudden dyspnoea, pleuritic pain, tachycardia, sometimes the only sign is unexplained hypoxia.
Clues: Asymmetric calf swelling · Sudden desaturation with clear lungs · Tachycardia out of proportion
The concept: Surgery is a perfect storm for Virchow's triad: stasis, endothelial injury, hypercoagulability. Prophylaxis is why mechanical and chemical measures appear on every postoperative order set.
Small bowel resection & anastomosisLaparoscopic cholecystectomyOpen appendectomy