Day One After Bowel Surgery: Reading the Whole Picture
Mr C is 68, weighs 68 kg, and is day one after an open right hemicolectomy (converted from laparoscopic). Pre-operatively his BP was 142/86, HR 68 and Hb 132 g/L. At 07:00 handover: HR 112 regular, BP 98/58, RR 22, SpO2 95% on 2 L/min, temperature 36.6 °C. He is drowsy but rousable and rates pain 3/10 on a morphine PCA. His urinary catheter has drained 30 mL in the last three hours. The abdominal drain contains 350 mL of blood-stained fluid from the last four hours. His abdomen is distended and firm and capillary refill is 4 seconds. He is prescribed 1 L sodium chloride 0.9% over 12 hours and paracetamol 1 g IV four times daily.
1. Calculate Mr C's urine output in mL/kg/h. Which observations concern you most, and what single physiological problem best explains all of them?
Read the worked answer
Urine output 30 mL over 3 hours = 10 mL/h. 10 ÷ 68 kg = 0.15 mL/kg/h. The accepted minimum is 0.5 mL/kg/h, which for him is 34 mL/h - he is producing less than a third of that.
Most concerning
- HR 112 against a baseline of 68 - a compensatory tachycardia.
- BP 98/58 with a pulse pressure of 40 and capillary refill of 4 seconds - cool, vasoconstricted peripheries.
- Drain loss of 350 mL in 4 hours (about 88 mL/h), blood-stained.
- Hb fallen from 132 to 96 g/L.
- Oliguria, distended firm abdomen, and new drowsiness.
One explanation Intravascular volume depletion, most likely from ongoing intra-abdominal bleeding plus third-space sequestration after open surgery. A falling Hb with a bloody drain, tachycardia, narrow pulse pressure, delayed cap refill and oliguria all point the same way.
Do not assume the drowsiness is 'just the morphine'. Opioids plus hypoperfusion is a dangerous combination, and the drain may under-estimate loss because blood pools in the abdomen.
2. State your first five actions in priority order, with your reasoning for each.
Read the worked answer
- Call for help and stay with him. This is a surgical emergency, not a ward-round problem. Request urgent surgical review and the rapid response/outreach team. Early escalation is the single biggest determinant of outcome.
- A–E assessment with high-flow oxygen, titrated to 94–98%, position him flat or with legs elevated (not sitting up), keep him warm. Recheck obs and repeat every 15 minutes; continuous SpO2 and ECG.
- Two large-bore IV cannulae and bloods: FBC, U&E, coagulation, lactate/VBG, and crossmatch 2–4 units (at minimum group and save). Anticipate blood products - do not wait for the Hb result to request them.
- Fluid resuscitation as prescribed (typically a 500 mL crystalloid bolus over 15 minutes) with reassessment after each bolus - but recognise this is a holding measure and that he probably needs blood and a return to theatre.
- Measure and document everything: hourly urine (check the catheter is not kinked or blocked), drain volumes, abdominal girth, pain score. Reassess pain carefully rather than increasing opioid for restlessness that may be hypoperfusion.
Hand over clearly using SBAR so the surgical team hears the trend, not just the numbers.
3. The prescribed 1 L of sodium chloride 0.9% over 12 hours delivers about 83 mL/h. Why is this not an adequate response, and what would you expect instead?
Read the worked answer
Why it is inadequate 83 mL/h is a maintenance rate for a stable, euvolaemic adult. Mr C is losing roughly 88 mL/h into a drain alone, before insensible losses, and is already oliguric and tachycardic. At 83 mL/h it would take over four hours just to replace what has already been lost - while more is being lost.
What is needed instead
- Resuscitation, not maintenance: boluses of crystalloid titrated to clinical response (HR, BP, cap refill, urine output, mentation) with reassessment after each.
- Blood products guided by crossmatch and, where available, major haemorrhage protocols.
- Definitive control of bleeding - surgical review and probable return to theatre.
Why large crystalloid volumes alone are harmful They dilute haemoglobin and clotting factors, worsen coagulopathy, cause hypothermia and tissue oedema, and can disrupt formed clot - reducing oxygen delivery at the very moment it is needed. Your role is to escalate the prescription mismatch rather than simply run the bag as written.