Time for capnography – everywhere

This title is based on the editorial by DR Whitaker in Anaesthesia 2011;66:544-9 titled “Time for Capnography – Everywhere” 

Anesthesiologists have adopted capnography as a standard of monitoring in operating rooms for 25 years. Despite proven value of capnography in operating rooms, its use in outside of the operating rooms has not matched that in the operating rooms. Anesthesiologists have understood the value of capnography and pulse oxymetry 25 years ago and did not wait for randomized control studies to prove their value in clinical practice before their introduction. Due credit should be given to the anesthesiology leadership at the American Society of Anesthesiologists, Anesthesiology Association of Holland, and Association of Anesthetists of Great Britain and Ireland to implement capnography as a standard of care based on predictive conclusions of retrospective analysis.  This has probably made anesthesia safer in the operating rooms.   What about outside of operating rooms? The reasons may be many. Instead of debating on the reasons why capnography has not become a standard outside of OR / OT, it is time to implement its use now everywhere outside of operating rooms, wherever, intubations, ventilations, and sedations take place. The current evidence, based on what can considered as a controlled study comparing the outcomes with and without capnography, should decisively go in favor of implementing capnography outside of OR /OT. The data from the studies show that in 2008-9 there were 16 airway deaths from the 3 million patients undergoing general anesthesia monitored with continuous capnography, giving a death rate of 1:180,000. Similarly, there were 18 deaths from a much smaller number of ICU patients receiving ventilation: 48000 during the study year, giving a death rate of 1 in 2700. This implies that it is 66 times more likely to have airway catastrophes in ICU where capnography is not used as compared to operating room where continual capnography is the standard of care. What is more alarming is the conclusion of the study group that 74% of ICU airway deaths could have likely been prevented had continuous capnography been used. This led to several recommendations to be implemented.

 British Journal of Anaesthesia 2011;106(5):632-42. 

In Intensive Care Unit: 

1.Capnography should be used for intubation of all critically ill patients irrespective of location.

2. Continuous capnography should be used in all ICU patients with tracheal tubes (including tracheostomy) who are intubated and ventilator-dependent. Cost and technical difficulties may be practical impediments to the rapid introduction of routine capnography. However, these need not prevent its implemenation.

3. Where capnography is not used, the reason should be documented in the chart.

4. Training of all clinical staff who work in ICU should include interpretation of capnography. Teaching should focus on identification of airway obstruction or displacement.  In addition, recognition of the abnormal (but not flat) capnograph trace during CPR should be emphasized.  

In Emergency Unit:

1.  Capnography should be used for all intubations in the ED

2. Capnography should be used for all anesthetized patients in ED

3. Capnography should be used for intubated patients during transfers from the ED to other departments.