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In DKA, three mechanisms shift potassium from inside the cells to the bloodstream: insulin deficiency removes the main driver of cellular uptake, the acidosis (pH 7.18) drives an H+/K+ exchange, and hyperosmolality adds solvent drag. So a serum K+ of 6.3 mmol/L at presentation usually hides a large total body deficit from the prior osmotic diuresis and vomiting. Per eTG DKA management, once the insulin infusion starts, potassium falls quickly as it moves back into the cells — hypokalaemia during treatment is a major, life-threatening complication, so K+ is monitored closely and replaced. Treating this as true hyperkalaemia and giving sodium resonium would strip out potassium that is already depleted and set the patient up for a dangerous fall once insulin is running.

Correct: oxygen to SpO2 ≥94%, a 30 mL/kg fluid bolus, a MET call, and two blood cultures before antibiotics.

Mr Nguyen meets MET call criteria (HR >110, RR >25, SBP <100, new confusion, SpO2 <92%) and Sepsis-3 criteria (suspected infection plus organ dysfunction — confusion, raised creatinine, lactate >2 mmol/L). The ACSQHC Sepsis Clinical Care Standard and the Surviving Sepsis Campaign direct two sets of blood cultures from separate sites before antibiotics, a 30 mL/kg NaCl 0.9% bolus in the first hour, and oxygen titrated to 94–98% for a non-COPD adult. Targeting ≥98% with a non-rebreather over-oxygenates and risks harm, and withholding fluids to wait for formal screening delays a time-critical intervention the nurse should start alongside escalation.

Correct cues: RR 26, BP 94/58, SpO2 89% on 4 L/min, and temperature 38.9°C.

The significant cues are the current, objective physiological changes that meet escalation thresholds: tachypnoea (RR 26) and hypotension (SBP <100) are MET and SIRS triggers under the Between the Flags / ADDS framework, SpO2 89% despite 4 L/min is oxygen-therapy failure, and 38.9°C confirms the febrile picture of sepsis. The elevated BSL is expected stress hyperglycaemia and does not change the immediate priority, the WBC is a historical result from yesterday rather than a cue about tonight, and type 2 diabetes is a static background factor. The point of the cue-recognition step is to act on what is changing now.

ICP 14 with CPP 85 — improvement. Right pupil now 4 mm and reactive — improvement. GCS 7T (up from 3T) — improvement. Urine output 280 mL/hr with Na+ 152 — requires immediate action. Hb 88 g/L (down from 102) — deterioration.

ICP under 20 with CPP well above 60, a pupil recovering from fixed-and-dilated, and a rising GCS all point to successful decompression. The finding that demands immediate action is the massive urine output (about 3 mL/kg/hr) with a rising sodium of 152 mmol/L, which strongly suggests post-neurosurgical central diabetes insipidus — the RN should notify the ICU consultant, check urine specific gravity, match fluid replacement to output and anticipate desmopressin, because uncontrolled DI causes severe hypernatraemia and secondary brain injury. The Hb drop from 102 to 88 g/L signals intra-operative blood loss to keep watching. Classifying each finding separately is exactly the reasoning the matrix format is built to test.

Highlight: “new headache and feels really drowsy”, “hard to rouse — GCS dropped to 12”, “RR is 28”, and “urine output over 6 hours was 180 mL”.

In a COPD patient on oxygen, new drowsiness with a falling GCS is the cardinal sign of hypercapnic encephalopathy (CO2 narcosis) — per eTG and TSANZ this mandates an urgent ABG, medical review and consideration of non-invasive ventilation, and a GCS of 12 is itself a MET criterion. RR 28 is a fresh escalation trigger, and 180 mL over 6 hours (about 30 mL/hr for 58 kg) sits at the oliguria threshold. The SpO2 of 91–93% is correct for the COPD target of 88–92% and is not a concern, and the elevated BSL is expected steroid effect the team already knows about. The format rewards picking out precisely the phrases that change management.

Most likely: septic shock secondary to urosepsis — evidenced by SBP 78 mmHg, lactate 5.1 mmol/L, pH 7.29, dysuria with rigors, and warm vasodilated peripheries indicating distributive septic physiology.

The ACSQHC Sepsis Clinical Care Standard and Sepsis-3 define septic shock as sepsis with hypotension plus a lactate over 2 mmol/L — both are present (SBP 78, lactate 5.1). The two-day history of dysuria and rigors identifies a urinary source progressing to bacteraemia, and the warm, flushed peripheries with tachycardia are the high-output distributive picture of early septic shock, which is what separates it from the cool, clammy peripheries of hypovolaemic or cardiogenic shock. This patient needs the sepsis pathway now: two blood cultures before antibiotics, IV antibiotics within 60 minutes, a 30 mL/kg bolus and urgent ICU review. HHS and DKA are distractors that cannot explain the fever, rigors and lactate driven by infection.

The RN should withhold the enoxaparin, contact the surgical registrar to confirm the safe post-spinal timeframe and document the reasoning — because this is a high-risk perioperative anticoagulation window after neuraxial anaesthesia, where premature enoxaparin risks spinal haematoma and paralysis.

ACORN, the NHMRC VTE prevention guidelines and ANZCA all specify that prophylactic low-molecular-weight heparin is not given until at least 4–6 hours after spinal needle removal — and ideally 12 hours when timing is unclear — to avoid an epidural or spinal haematoma, which can cause permanent paralysis. Here the spinal was at 0815 and it is 1430 (about 6 hours), right at the lower boundary, and the missing pre-op dose time adds uncertainty. Withholding and confirming with the registrar is the safe, ACORN-compliant action; the RN does not have the authority to independently decide the post-spinal timing, giving the full dose now would be unsafe, and a half dose has no evidence base.

Condition: hyperosmolar hyperglycaemic state (HHS). Actions: insert a large-bore IV cannula and start 0.9% NaCl at 500 mL/hr for the first two hours; withhold glipizide and document it as ceased on a registrar verbal order. Monitor: BSL and serum osmolality 1–2 hourly (aiming BSL fall ≤5 mmol/L/hr, osmolality ≤3–4 mOsm/kg/hr); serum potassium every 2 hours before and during any insulin.

This meets HHS criteria — BSL >33, osmolality >320, minimal ketones and a near-normal pH — which per eTG predominates in older type 2 diabetics with intercurrent illness and poor intake. Fluid resuscitation, not insulin, is the first-line action: it addresses the hypotension and lowers BSL by dilution and restored renal excretion, and eTG explicitly withholds insulin until fluids are established to avoid a rapid osmolality drop and cerebral oedema. Withholding the sulphonylurea prevents hypoglycaemia as glucose corrects. The two monitoring parameters guard the two biggest dangers: over-rapid correction (osmolality) and insulin-driven hypokalaemia (a K+ of 3.2 will fall further once insulin runs).