Effective ventilation during CPR via an LMA‐Supreme

A 75 kg, ASA 2 patient, enrolled in a study to evaluate the LMA-Supreme™ (Intavent Orthofix, Maidenhead, UK), was due to undergo axillary clearance. Anaesthesia was uneventfully induced with fentanyl and TCI propofol. The airway was easily secured with an LMA-Supreme and controlled ventilation was initiated, achieving a square wave capnogram, normocapnia and 100% oxygen saturation. Fifteen minutes after induction of anaesthesia while preparing for surgery the patient’s blood pressure was noted as 70/34 mmHg and, when repeated, was not recordable. This coincided with an apparent ECG arrhythmia consistent with ventricular fibrillation. During initial advanced life support assessment there was no palpable pulse. Chest compression was commenced immediately and ventilation continued with 100% oxygen via the LMA-Supreme. Chest compression continued for 1 min while the patient was assessed. At this point it was noted that the capnogram had normal morphology and a normal end-tidal carbon dioxide value. The patient showed no signs of cyanosis or other signs of poor perfusion. Cardiac compressions were stopped and the ECG showed normal sinus rhythm at a rate of 55 bpm. Following metaraminol 1 mg the blood pressure was recorded as 75/40mmHg and improved further; a peripheral pulse was felt with some difficulty. A 12-lead ECG showed a sinus bradycardia of 50 bpm with no new changes. After careful consideration, surgery went ahead without further incident. It is notable that the LMA-Supreme enabled effective ventilation throughout the period of cardiac compression. There was no airway leak and no impediment to ventilation. Not only was this beneficial for our patient but it also enabled us to rapidly decide that, as capnography was normal, it was very unlikely that cardiac arrest had in fact occurred. We later determined the apparent cause to be a loose ECG lead accurately mimicking a VF arrest rhythm, coinciding with profound hypotension. The effectiveness of the LMA-Supreme in this situation suggests possible benefits for its future use during cardiac arrest and resuscitation. The LMA-Supreme is designed to enable rapid reliable insertion, effective ventilation and improved protection of the airway compared to the LMA-Classic™ (Intavent Orthofix). The ability to rapidly secure the airway and immediately carry out asynchronous ventilation is of immense value in maintaining cardiac output during cardiopulmonary resuscitation and is emphasised in latest resuscitation guidance [1]. The ability to continuously provide and monitor ventilation is potentially beneficial, both in avoiding hypoxia and in determining return of spontaneous circulation. We suggest that further study in the role of the LMA-Supreme with a view to its role in resuscitation is indicated.