Pulses Not Palpable

The patient was a 52 yo woman scheduled for an umbilical hernia repair. Her preop assessment was unremarkable other than having controlled for hypertension and having a BMI of 36.

A 22g cannula was placed on the ventral side of the L forearm as no larger veins could be found. Monitoring was attached and preoxygenation commenced.

A  Igm dose of cephalothin was given IV, followed by fentanyl 100mcg and midazolam 1.5mg.There was no change in pulse or BP after about one minute so propofol 160mg and rocuronium 30mg were administered.

 

Within about 30 secs she was noted to have a bright pink rash on her upper torso and arms. Following a brief period of bag and mask ventilation she was intubated uneventfully. The CO2 trace was normal shape but the end tidal level was 18 mmHg. O2 saturation was 88%. The NIBP was not giving a reading.  No pulses were palpable. The surgeon was requested to feel for a femoral pulse without success.

Extra nursing assistance was called for. (There were no other anaesthetists in this small hospital at this time). Adrenaline 100mcg was given IV. The patient was on a ventilator by this time on 100% O2, with normal pressures and a rate of 7 breaths per minute. The patient maintained an oximetry trace throughout, the SaO2 climbing to 95% within a few minutes. The patient was placed in a slightly head down position. The ET CO2 was 36 mmHg by this time which was somewhat reassuring indicating improved perfusion. HR had changed little from around 80 bpm until after adrenaline had been given when it climbed to about 120.

Yet still no pulses were palpable.

Adrenaline 200mcg was given and a weak pulse became palpable for about 1 minute before disappearing again. Further boluses of 200mcg were given to maintain a palpable pulse. More IV access was obtained. This was difficult. After a few attempts a 20G cannula was inserted on the ventral side of the L wrist. 2L of crystalloid were given over about a 20 minute period. 

A transfer to an ICU by an emergency mobile intensive care ambulance was requested. An adrenaline infusion was started and a rate of 15 mcg /min was required to maintain a systolic BP of around 80.

In ICU the patient required adrenaline (subsequently  changed to noradrenaline and continued for about 12 hours). She was extubated the following morning and made a full recovery. Tryptase taken at 2 hours after induction came back at 67 mcg/L (approx 5 times normal). Skin testing at 6 weeks showed a strongly positive reaction to rocuronium.

 

Comment 1

 As the anaesthetist involved I found this case stressful. A case like this comes totally unexpectedly. There is a lot to be done in a short time. While I was fairly sure the diagnosis was anaphylaxis I felt I had to keep reviewing other possibilities to be sure I was not missing anything. So I spent most of my time at the head of the patient observing the monitor assessing the effects of the treatment and delegating tasks. These tasks included feeling for pulses and searching for veins for cannulation, drawing up adrenaline, getting more nursing assistance, contacting the ambulence service and arranging the ICU transfer.

Comment 2

One thing I feel is important in such cases is the need to give adrenaline early and keep titrating it in to restore BP to a satisfactory level. Secondly is that it may be a difficult decision whether to “scoop and run” or stay and stabilise. In this case it was considered the establishment of arterial and central lines may have taken quite a long time in a less than optimum environment.

Comment 3

The optimum time to take blood for serum tryptase is around 1 -2 hours post initial event. It may remain elevated as long as 6 hours after the initial event.

Comment 4

It has been reported that large volumes of fluid should be given concurrently with the adrenaline in cases such as these to restore circulating fluid volume. Giving 4 - 5 L of crystalloid may have been a good thing to do in this cases had venous access enabled that.

Comment 5

Immediately following a case such as this it is important to carefully document what has happened in the patient record. It is likely that it will be scrutinised.

Comment 6

A slow ventilator rate was selected to ensure no compromise of venous return from elevated intra-thoracic pressures.

Query 1

Does the fact that an oximetry trace was maintained throughout the case indicate that vital organs were being adequately perfused?

Query 2

What is the optimum patient position for resuscitation in this situation? Is it head down about 10 degrees or is it supine with the legs elevated?