Capnography during cardiopulmonary resuscitation.

Use of waveform capnography during cardiac arrest was recomended in the 2010 International Consensus on Cardiopulmonary esuscitation (CPR) Science with Treatment Recommendations.1 primary benefit includes confirmation that a tracheal tube (or ther airway device) has been placed correctly and is providing entilation of the lungs.2 Capnography is considerably more relible than either clinical assessment by auscultation or observation f chest wall movement. The recent 4th National Audit Project f The Royal College of Anaesthetists and Difficult Airway Society xamined Major Complications of Airway Management in the UK. t did not focus on airway management during cardiac arrest, but t included 11 instances where failure to use or correctly interret capnography led to unrecognised oesophageal intubations uring cardiac arrest, most of which led to avoidable death or rain injury.3,4 We can assume that the incidence of unrecognised esophageal intubation is higher when waveform capnography is ot used during cardiac arrest. There is strong evidence to support he use of waveform capnography in this situation (CPR will generte an attenuated, but not absent, end-tidal CO2 trace),5 with data emonstrating 100% sensitivity and 100% specificity in identifying orrect tracheal tube placement.6 In contrast to waveform capnogaphy, studies of alternative devices to determine correct tube lacement (such as colorimetric end-tidal CO2 detectors, syringe spiration oesophageal detector, self-inflating bulb oesophageal etector and non-waveform end-tidal capnometers) have been hown to have accuracy that is not substantially better than clinical ssessment.7–15 During cardiac arrest, waveform capnography may also be used o guide the effectiveness of chest compressions and to provide an arly indication of return of spontaneous circulation (ROSC). Howver, there is currently insufficient evidence to recommend the use f end-tidal CO2 monitoring as a method of prognostication during ardiac arrest.1 In this issue of the journal, Heradstveit and colleagues from he Emergency Medical Service of Haukeland University Hospital n Bergen, Norway, present data that suggest capnography may ecome a more useful tool for optimising and individualising ALS n patients experiencing of out-of-hospital cardiac arrest (OHCA).16 retrospective observational study was performed using data ollected routinely from 918 OHCA patients. Of these, 194 were xcluded and 149 did not have capnography data recorded. Data ere analysed from the remaining 575 patients. Based on all availble clinical evidence, the cause of cardiac arrest was considered o be cardiac in 58%, respiratory in 20%, pulmonary embolism (PE) n 2% and unknown in 19%. Patients who developed cardiac arrest rom a respiratory (excluding PE) cause were observed to have