Tuesday January 30, 2007

Before today's pearl, here is a comment on pearl from January 24, Arterial and venous lactate

"I would also add that: Mixed venous lactate is same as arterial lactate and does not need any correction. This can be drawn from central venous catheter or PAC".

Surindra J. Singh, M.D.

VAMC, Salem, VA 24153

Air in LMA

Scenario: You encountered a difficult intubation and was unable to pass ETT (endotracheal tube). You took an option of inserting LMA (Laryngeal Mask Airway) till further help arrives. How much air should you push to inflate cuff of LMA ?


A good rule of thumb

For (adult) women - 15-20 ml
For (adult) men - around 25 ml


See slide presentation on LMA here for techniques and basics of insertion (From Clincon 2000, Airway skills Lab, The Florida Association of Emergency Medical Services Educators, Florida)

Monday January 29, 2007


What's the right length of endotracheal tube (ETT) for oral intubation?

As a gold standard the only way to make sure that tip of ETT is atleast 2 cm away from carina (or at appropriate place) is via chest X-ray. But there are many bedside quick tricks/formulae described in literature. One such formula 1 which also found to have good clinical correlation, is

ETT length (to be taped) at incisors = patient's height in cms / 10+5

Like, if patient's height is 170 cm, ETT should be taped at

170/10 + 5 = 22 cm


Another trick is to have ETT's cuff palpable at sternal notch, a technique described about 40 years ago ! 2


Related previous pearl: Movement of endotracheal tube (ETT) with neck


References:

1. Anaesthesia Intensive Care 1992; 20:156;
2. Anesthesiology 1964; 25:169