Septic shock with conflicting resuscitation targets
A 68-year-old man with type 2 diabetes and chronic kidney disease (baseline creatinine 180 micromol/L) presents with a 3-day history of fever and right lower lobe pneumonia. On arrival: temperature 39.1 C, heart rate 124/min, blood pressure 82/48 mmHg, respiratory rate 30/min, SpO2 91% on 15 L non-rebreather. He is drowsy but rousable. Lactate 5.8 mmol/L, creatinine 260 micromol/L, urine output 15 mL over the last 2 hours. He weighs 95 kg. A 1 L crystalloid bolus has already been given by the paramedics. The intensive care registrar is 20 minutes away and the emergency physician asks you whether to give more fluid, start vasopressors through a peripheral line, or wait. The nearest ICU bed is 40 minutes away.
1. Outline your immediate resuscitation priorities over the next 30 minutes, justifying each intervention with the physiology and the constraints of this setting.
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Priorities are oxygen delivery, perfusion pressure, and source control, delivered in parallel rather than sequentially.
Airway and oxygen. He is drowsy with SpO2 91% on high-flow oxygen; this is failing oxygen therapy in a patient with likely exhaustion. Call for airway support and prepare for intubation, but do not delay haemodynamic resuscitation. Pre-oxygenate, use a hemodynamically neutral induction plan, and anticipate post-intubation hypotension from loss of sympathetic tone and positive intrathoracic pressure.
Fluid. He has received 1 L. Give a further 500 mL balanced crystalloid over 15 minutes and reassess after each bolus using capillary refill, mentation, lactate trend, and a focused cardiac assessment if available. Do not give a fixed 30 mL/kg (2.85 L) blindly: he has CKD and a history suggesting he may be fluid tolerant or not, and over-resuscitation worsens gas exchange and tissue oedema. The endpoint is improved perfusion, not a volume target.
Vasopressors. Do not wait for central access. Start noradrenaline through a well-sited, monitored peripheral cannula in a large proximal vein while central access is arranged. Targeting a MAP of at least 65 mmHg early limits the duration of hypotension and reduces the fluid volume needed.
Antibiotics and source control. Blood cultures then broad-spectrum antibiotics within the first hour, covering typical and atypical pathogens given severity. Consider whether a drainable focus exists.
Disposition. Escalate to the retrieval service early; the 40-minute transfer should not be delayed by attempts to achieve perfect physiology on site.
2. Two hours later, after intubation and 2.5 L of fluid, he remains hypotensive on noradrenaline 0.35 microgram/kg/min with a lactate of 6.4 mmol/L, mottled knees, and a rising creatinine. Bedside ultrasound shows a plethoric inferior vena cava with no respiratory variation and a hyperdynamic left ventricle. What is your interpretation and what will you do next?
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The picture is consistent with a patient who is no longer fluid responsive and is likely on the descending limb of the Frank-Starling curve: a plethoric, non-variating IVC with a hyperdynamic, underfilled-looking ventricle in a ventilated patient suggests the heart is emptying well but the circulation is failing for another reason. In sepsis this is most often vasoplegia with maldistribution, and possibly a sepsis-related cardiomyopathy that has not yet been recognised.
Actions:
- Stop fluid loading. Further boluses are likely to worsen pulmonary oedema and gas exchange without raising cardiac output. Document this decision explicitly.
- Escalate vasopressor support and consider a second agent. Add vasopressin 0.03 units/min to reduce noradrenaline requirements and reduce arrhythmia risk. Reassess MAP target; in a patient with chronic hypertension a higher target may be appropriate, but the evidence for higher targets is weak.
- Assess cardiac function formally. A focused echo looking at LV and RV function, and a measure of cardiac output, will distinguish vasoplegia from cardiogenic contribution. If LV function is poor, consider inotropy rather than more fluid.
- Exclude other causes of refractory shock: adrenal insufficiency (consider a random cortisol and discuss hydrocortisone), pneumothorax, abdominal compartment syndrome, and inadequately controlled source.
- Reassess antibiotic adequacy and source control with the surgical team; refractory shock with a persistent focus mandates drainage.
- Discuss early with the retrieval service and consider whether transfer should occur on vasopressor support rather than after weaning.