Rapid Response Systems and MET Calls — Viva

Long Case Viva Defence

Candidate's opening statement (model answer)

"Mr David Chen is a 68-year-old retired engineer, admitted three days ago with a left lower limb cellulitis, who has acutely deteriorated overnight with a rising NEWS2 from 2 to 8 over four hours, precipitating a MET call at 22:00. He has a background of type 2 diabetes on metformin and empagliflozin, ischaemic heart disease with a prior NSTEMI on aspirin, atorvastatin, and bisoprolol, and stage 3 chronic kidney disease with a baseline creatinine of 130. [1]

His main problems are:

1. Septic shock with multi-organ involvement — refractory hypotension at 88 over 52 despite a fluid challenge, lactate 4.0, mottled peripheries, oliguric at 20 mL per hour.
2. Acute kidney injury with hyperkalaemia — creatinine risen from 130 to 195, potassium 5.6.
3. New atrial fibrillation at a ventricular rate of 124, almost certainly secondary to the sepsis and the electrolyte disturbance.
4. An afferent-limb failure — the NEWS2 crossed the intermediate threshold at 19:00 and the emergency threshold at 21:00, but the MET call was not made until 22:00, a delay that is the system learning point. [1]

My immediate priorities are the continued ABCDE resuscitation with cautious fluid in 250 mL aliquots given his ischaemic heart disease, early noradrenaline if he is not fluid-responsive, treatment of the hyperkalaemia with calcium gluconate and insulin-dextrose, urgent source identification with a surgical review of the limb for necrotising infection, escalation to ICU for vasopressor and possibly renal replacement therapy, and an early, honest conversation with the family about the ceiling of care given the severity of the acute illness and his comorbidities." [1]

Examiner probing questions and model answers

Q1: "Walk me through the afferent-limb analysis. The NEWS2 crossed 5 at 19:00 and 7 at 21:00, but the MET call was at 22:00. What failed, and what is the system fix?" [1]

"The afferent limb failed at both thresholds. A NEWS2 of 5 to 6 is the medium-risk threshold mandating an urgent ward-registrar review within 30 minutes and hourly monitoring; a NEWS2 of 7 or more is the high-risk emergency threshold mandating an emergency critical care assessment within minutes [3]. The patient crossed both without the appropriate response until the call was made an hour after the emergency threshold. This is the classic afferent-limb failure that the MERIT study exposed — the team was called to only 30 per cent of patients who met criteria [1]. The system fixes are the ward education in recognising and acting at the intermediate threshold (not waiting for the emergency threshold), the visible observation chart that displays the trend, the bedside escalation signage, and the feedback to the ward team after the event. The cultural message — that it is always acceptable to call — is reinforced by the senior staff supporting, not criticising, the call. The quality improvement limb closes the loop: the audit of the call rate, the proportion of patients meeting criteria who were called, and the outcome review feed back into the ward education."

Q2: "How do you justify cautious fluid in a patient in septic shock? Is that not undertreating him?" [1]

"The Surviving Sepsis Campaign 2021 recommends 30 mL per kilogram of crystalloid in the first three hours for sepsis with hypoperfusion [5], and I am not abandoning that — I am modifying the delivery for his ischaemic heart disease and likely diastolic dysfunction, which make him vulnerable to fluid overload and pulmonary oedema. The principle is that the comorbidity dictates the aliquot size and the reassessment frequency, not the total amount. I give 250 mL of balanced crystalloid over 15 minutes, reassess for fluid responsiveness (a rise in blood pressure, a fall in heart rate, an improvement in capillary refill) and for overload (a rise in JVP, new crackles, a fall in SpO2), and repeat if he is responsive and not overloading. If he is not fluid-responsive after two aliquots — which, given his refractory hypotension, is likely — I start noradrenaline early via a central line to restore the MAP to above 65. If I have a focused echocardiogram or a passive leg raise, I use it to guide the fluid dynamically. Undertreating him would be failing to resuscitate; overtreating him would be precipitating pulmonary oedema in an ischaemic heart. The aliquot-and-reassess method delivers the resuscitation safely."

Q3: "What is the role of the MET call in his ceiling-of-care conversation?" [1]

"The MET call surfaces the conversation. He is a previously independent 68-year-old with potentially reversible septic shock, which favours escalation, but he has ischaemic heart disease and chronic kidney disease, and the severity of the acute illness (refractory shock, AKI, hyperkalaemia, new AF) raises the question of whether ICU support will restore him to an acceptable quality of life. The MET call is the trigger for the conversation — the moment when the deterioration makes the goals-of-care question live. I ask the family early and gently whether he has an advance care directive and what he would want. The observation from MERIT that the MET system increased the rate of not-for-resuscitation orders is part of the system's function, not a side effect [1]. For this patient, I would offer a time-limited trial of ICU — maximal support for 48 to 72 hours, with a clear review point — as the considered middle path. If the treatment is working and he is recovering towards his baseline, we continue; if it is not, we refocus on comfort. I do not frame this as all-or-nothing, and I keep the family informed at every step."

Q4: "Give me the SBAR handover you would deliver to the ICU registrar." [1]

"Situation: 'This is Dr Lee, the medical registrar. I am calling about Mr Chen in bed 9, a 68-year-old man admitted three days ago with cellulitis, who has acutely deteriorated with a NEWS2 of 8 and had a MET call an hour ago.' Background: 'He has type 2 diabetes on metformin and empagliflozin, ischaemic heart disease with a prior NSTEMI on aspirin, atorvastatin, and bisoprolol, and stage 3 chronic kidney disease with a baseline creatinine of 130. He has been on IV flucloxacillin since admission.' Assessment: 'His current observations are: respiratory rate 28, SpO2 90 per cent on 15 litres via a reservoir mask, heart rate 124 in new atrial fibrillation, blood pressure 88 over 54 after a 500 mL fluid challenge, GCS 14 with new confusion, temperature 38.9. His lactate is 4.0, his creatinine has risen from 130 to 195, and his potassium is 5.6. He is oliguric at 20 mL per hour. I have given high-flow oxygen, broad-spectrum antibiotics, a cautious fluid challenge with reassessment given his ischaemic heart disease, and calcium gluconate and insulin-dextrose for the hyperkalaemia.' Recommendation: 'I would like you to come and review him on the ward now. My concern is refractory septic shock with multi-organ failure — he is likely to need noradrenaline for the blood pressure and possibly renal replacement therapy for the hyperkalaemia. I think he needs ICU admission, and I would like your assessment and the discussion about the ceiling of care given his comorbidities.'" [1]

Q5: "What is the evidence that the system you are invoking actually works?" [1]

"The evidence is nuanced, and I carry it honestly. The MERIT study, the only cluster-randomised trial, found that the MET system increased calls from 3.1 to 8.7 per 1000 admissions but did not significantly reduce the composite primary outcome of cardiac arrest, unexpected death, or unplanned ICU admission [1]. The trial was underpowered, contaminated, and short in implementation. The meta-analytic evidence is more favourable: Chan's 2010 review showed a 33.8 per cent reduction in non-ICU cardiopulmonary arrests, though no significant reduction in overall hospital mortality [4], and the DeVita consensus conference formalised the four-limb model that frames the system [2]. My reading is that the system works by changing the safety culture, surfacing deterioration earlier, and facilitating appropriate escalation — and the cardiac arrest reduction is the consistent signal. The mortality benefit is plausible but diluted by the ceiling-of-care patients and the before-and-after design. For this patient, the question is whether calling the team and setting the plan was the right thing — and it was."