Maternal Airway - The Anesthetic Minefield

To paraphrase the emminent Prof. Forrest Gump, "The maternal airway is like a box of chocolates, you never know what's inside."

The anesthesiologist is required to have the most intimate knowledge of the anatomy of the airway.  For if the airway is lost, whether by trauma or drugs, the patient's demise is soon to follow. Navigating the airway of a pregnant woman may be a particularly harrowing experience.  This is the reason that regional anesthesia (spinal or epidural) is preferred for elective C-Sections.  As a result, at night, when the staff are less experienced and tired, occur the most stressful of medical emergencies: loss of the airway during an emergency C-Section.  The stakes are very high, literally the life of mother and child are in danger. The reason for the difficulties in securing the airway lie in the edema or swelling of the soft tissue of the oropharynx during pregnancy which is a normal occurrence. This may turn a normal airway into a "difficult" airway. Emergency protocols exist, but they only serve to guide, experience is the best teacher.

When intubating a patient, we try to bring three planes into alignment: The oral, the pharyngeal and the laryngeal.

If all goes well, then this is what you are supposed to see:

If this is the picture, then it's easy as pie to pass an endotracheal tube through.

Yesterday, at the end of the day, I was supervising the anesthesiologists on call who were finishing up the day's cases.  I had another hour or so to go before the senior on call could take over and I could go home. 

Then a call came, "anesthesiologist stat to the OB/GYN OR"!  Barreling up 5 flights of stairs (the elevators are notoriously slow), I called the ICU which was on the same floor and asked them to send someone.  I entered the OR before he did.  Three anesthesiologists were there, it was an emergency C-Section with a general anesthetic.  They told me that it was an impossible intubation and that they had tried everything including a laryngeal mask airway, and a video assisted laryngoscope, but to no avail.  They were just barely able to ventilate the patient by mask.  Her face seemed swollen with the usual edema, I could only imagine what was going on inside.  The operation was on hold during the efforts to secure the airway. The video assisted laryngoscope was turned on, the reason they couldn't get the tube in was because the special guide wire used with this technique had been lost or misplaced.  The guide wire is malleable but stiff and assists in navigating the tube through odd angles. I asked for a tube with a regular guide wire. I bent the tube into a hockey stick shape.  Inserting the scope, the airway looked like a bowl of cherry jello.  I could just barely make out the arytenoid cartilage at the base of the cords in the upper left quadrant of the screen.  I tried once, twice, I just couldn't get the tip of the tube anterior enough into the larynx.  I bent the tube into a horse shoe shape and said a silent prayer. The tip was just past the cords.  Holding the tube in my fist for all I was worth, I ordered, "remove the guide".  The guide was out, I pushed the tube all the way home.  The capnograph showed CO2 in the the tube, meaning, it's in the trachea. Auscultating the left lung field, no breath sounds.  Gingerly, I pull the tube back until I hear equal breath sounds over both lungs. "OK fix the tube in place".

Nonchalantly, I leave the OR, "thank you all for attending our emergency intubation" I call out.  "You may resume the operation".