Postoperative day 4 after open colectomy: tachycardia, oliguria and a reassuring resident
Miriam, 64, is on postoperative day 4 after an open right hemicolectomy with primary anastomosis for stage II colon cancer. She has well-controlled hypertension, BMI 31, and no other major comorbidity. Analgesia is morphine patient-controlled analgesia; she has prophylactic enoxaparin 40 mg subcutaneously daily, last given 8 hours ago, and cefazolin was stopped on day 1. Overnight she tells you 'something is wrong'. HR 118, BP 104/62 (admission 138/82), RR 24, temperature 38.3 °C, SpO₂ 95% on room air. Her abdomen is distended and diffusely tender, pain 8/10 despite PCA boluses, no flatus since surgery, and she has vomited twice. Urine output is 60 mL over 3 hours through a catheter. Lactate 3.2 mmol/L, WBC 15.8, creatinine 1.4 mg/dL (baseline 0.8), glucose 12 mmol/L. The surgical resident says to 'give a litre of fluid and watch her until the morning round'.
1. What is your differential and what are your first-30-minute priorities? State clearly what you would do about the resident's instruction.
Read the worked answer
Differential, in order of danger: anastomotic leak with intra-abdominal sepsis; intra-abdominal abscess or collection; aspiration pneumonia or line infection; hypovolaemia from third spacing or vomiting; opioid-driven ileus with dehydration. The combination of tachycardia, fever, distension, diffuse tenderness, vomiting, oliguria, rising creatinine and lactate 3.2 on day 4 after a fresh anastomosis is leak until proven otherwise - day 4 to 7 is the classic window.
First 30 minutes:
- Full set of observations, repeat BP/HR, urine output, pain score, and a focused examination including the wound and any drain fluid (bilious or faeculent drainage is a red flag).
- Oxygen if saturations fall, continuous monitoring, large-bore IV access, blood cultures, lactate, full blood count, chemistry, coagulation, group and save.
- Fluid challenge is appropriate but not a substitute for escalation: 500 mL balanced crystalloid over 15–30 minutes with reassessment of HR, BP, urine output and lactate. If there is no haemodynamic response, that itself supports a septic/third-space cause rather than simple dehydration.
- Escalate now: activate the rapid response or call the on-call surgeon and the responsible physician; document the observations given and the advice received. 'Give a litre and watch' is not acceptable for a febrile, oliguric, lactataemic patient with a fresh anastomosis - ask specifically for senior surgical review and imaging (CT abdomen/pelvis with contrast).
- Analgesia review, antiemetic, keep nil by mouth pending surgical decision.
2. Why do the creatinine and the enoxaparin matter to your nursing plan, and what would you change about her analgesia?
Read the worked answer
Creatinine 1.4 from 0.8 means her renal function has fallen by roughly 40% - most likely from hypovolaemia and/or sepsis, but it changes drug handling and it is a warning sign of inadequate perfusion. Consequences:
- Enoxaparin: low-molecular-weight heparin is renally cleared. A prophylactic 40 mg dose is generally still acceptable, but accumulation raises bleeding risk, and if she deteriorates further toward severe renal impairment or needs a procedure, the recent dose matters for the anaesthetist and for any neuraxial procedure. Document the time of the last dose, check the platelet count (heparin-induced thrombocytopenia), and ask the prescriber whether dose adjustment or monitoring is needed. Do not simply omit it on your own.
- Other renally cleared drugs: review antibiotics not yet started, opioids, and any contrast.
Analgesia: the PCA morphine is likely contributing to ileus and vomiting, and she is now hypotensive and possibly septic - both raise the risk of sedation and respiratory depression. Actions: check sedation score and respiratory rate, stop or reduce the PCA with a prescriber's order, avoid further boluses, and consider a non-opioid or opioid-sparing plan. Naloxone must be available but is not indicated unless she is over-sedated. Reassess pain after each change and document.
3. Twelve hours later the drain contains brown, foul-smelling fluid and her BP is 88/50. What happens next, and what must your documentation contain?
Read the worked answer
This is frank anastomotic leak with septic shock - brown, foul drain fluid from a fresh colorectal anastomosis is diagnostic until proven otherwise, and the hypotension confirms decompensation.
Immediate sequence:
- Call for help (rapid response/senior surgeon) and start the sepsis pathway: high-flow oxygen, two large-bore lines, balanced crystalloid boluses of 500 mL with reassessment, blood cultures before antibiotics if not delayed, and broad-spectrum antibiotics within one hour as prescribed - covering Gram-negative and anaerobic organisms.
- Strict hourly urine output, lactate every 2 hours, and prepare for theatre or CT depending on stability. Unstable patients go to theatre, not the scanner.
- Prepare the patient: consent discussion with the surgeon, group and save/crossmatch, stop enoxaparin as instructed, nil by mouth, mark the drain, keep it on free drainage and monitor output volume and character hourly.
- Notify the family and prepare for probable ICU admission.
Documentation must include: the exact observations and timestamps, when you first noticed the change, who you informed and when, what advice was given and by whom, interventions given with times, the drain output described objectively, escalation to the next tier if the response was inadequate, and the patient/family communication. Write facts, not conclusions, in the nursing record.