ICU Fellowship Vivas – MH, Failure to Wean and Pancreatitis
Dr Swapnil Pawar
Viva answers written by – Dr Madhuri Anupindi
BG: diabetes, Graves’ disease and rheumatoid arthritis for which he takes regular prednisolone.
On ICU admission: confused, restless, diaphoretic with a temperature of 42 degrees. Provide a differential diagnosis for his fever and outline your management plan.
There are numerous potential infectious and non-infectious causes for this man’s fever.
Management would involve simultaneous resuscitation including cooling, thorough evaluation and investigation of the cause of his deterioration, and specific and supportive management.
A – assess
B – sats and full monitoring, resp rate, supplemental oxygen, CXR
C – IV access, HR, BP, check lines, IVF bolus and assess fluid status, likely art line/CVC, vasopressors if required, culture widely
D – GCS, focal neurology and pupils,
E – BSL, start cooling, artic sun, blanket, cool fluids, ice packs, insert IDC with temperature sensor
Would involve history, exam and investigations
How would you monitor the temperature in this patient?
I would do this via an IDC with a temperature sensor as it allows for the patient’s temperature to be measured continuously, he is very likely to require an IDC regardless, is considered to be reflective of core temperature and is recommended by current guidelines.
Briefly outline the potential methods of cooling this patient.
There are multiple non-invasive and invasive methods of cooling this patient.
Non-invasive methods include:
Invasive methods include:
Many of these methods may not be tolerated by this patient in his current state due to his confusion, and may also cause shivering. Therefore, intubation may be required to facilitate temperature control and to reduce metabolic demand.
What are the key features of malignant hyperthermia?
Malignant hyperthermia is a genetic disorder of skeletal muscle which allows for excessive myoplasmic calcium accumulation after exposure to certain agents resulting in sustained muscle contraction and breakdown. Common clinical features include:
Investigative features include:
What are the potential drugs used in ICU that can give rise to MH
The main potential drug which is used in ICU is suxamethonium. Volatile anaesthetic agents such as sevoflurane are also a common trigger, although these are rarely used within the ICU.
Numerous potential causes, likely multi-factorial with a combination of complications from her prolonged stay in ICU and potentially new pathology
How will you optimise her prior to her next extubation?
Optimisation would require identification and treatment of the contributors to her failed extubation. This would first involve a thorough evaluation including targeted history, exam and investigations.
History and exam particularly focused on:
What are the indications and complications of a tracheostomy?
Complications: these can be procedural, acute and chronic.
What is the optimal timing of a tracheostomy and is there evidence for same?
There is no consensus on the optimal time to perform a tracheostomy as this is dependent on the individual patient and environment. An ‘early tracheostomy’ is generally thought of as those performed within 10 days of intubation. Proponents hypothesise that early tracheostomy may allow for less sedation, improved patient comfort, fewer complications from an oral endotracheal tube, shorter ICU stay and therefore reduced morbidity and mortality. Proponents against state that it subjects more patients to the risks of tracheostomy, some of whom may not go on to actually require thm.
The major trial regarding timing was TracMan from 2013 which studied 909 intubated patients who were thought to require at least 7 more days of ventilatory support. They were randomised to undergo a tracheostomy within 4 days of ICU admission or after day 10. There was no mortality difference between the two and no statistically significant difference in duration of mechanical ventilation or ICU length of stay. However, this trial did not include patients who may have required a tracheostomy for non-respiratory reasons and less than half of the patients in the ‘late’ group ended up requiring a tracheostomy.
A Cochrane review in 2015 of almost 2000 patients (the majority of which come from TracMan) found a statistically significant mortality benefit from early tracheostomy with a number needed to treat of 11, and that the early group and a decreased duration of sedation but no significant decrease in duration of mechanical ventilation. However, they advised that these findings were only suggestive as there was minimal high quality evidence available.
The optimal timing of tracheostomy is ambiguous and not well established. Some patients such as those with significant neurological dysfunction or severe facial burns may benefit from early tracheostomy. Decisions regarding timing relies on clinical experience and consideration of individual patient factors.
This patient is shocked and requires urgent simultaneous resuscitation, evaluation and treatment. I am concerned that he has severe pancreatitis but other possible differentials include:
On investigation, his lipase is 2000 and CT abdomen confirms a diagnosis of pancreatitis. How will you manage him?
Management consists of resuscitation, logistic, specific and supportive management.
He continues to be febrile, your registrar asks about commencing antibiotics, what will you tell her?
There is no role for routine prophylactic antibiotics in pancreatitis and no evidence that it improves patient-centred outcomes. I would consider commencing antibiotics if:
How will you approach his nutrition?
Enteral nutrition is preferable to parenteral nutrition. Assuming this patient has severe pancreatitis, I would start enteral nutrition within 48 hours via an NG or NJ tube at a low rate and slowly increase as tolerated aiming 25 – 35kcal/kg/day. I would only start TPN if enteral nutrition is not tolerated after 5- 7 days.