Prone CPR for transient asystole during lumbosacral spinal surgery.

This report describes a case of sudden profound bradycardia and

transient asystole during lumbar microscopic discectomy, which required

initial cardiopulmonary resuscitation (CPR) in the prone position. A

43-year-old, 110 kg, 184 cm male presented for L4-L5 microscopic

discectomy for left lower leg pain and weakness. His past medical

history revealed moderate smoking and alcohol intake, and hypertension

treated with lisinopril. He had no history of previous arrhythmia.

Preoperative examination, serum electrolytes and electrocardiogram were

unremarkable. Following an intravenous induction with standard

monitoring, the patient was positioned prone-kneeling on an Andrews

table. One hour into the procedure, after a brief pause in surgery, with

resumption of the surgical stimulus the patient suddenly became

bradycardic. The electrocardiogram initially showed junctional

complexes. His heart rate further declined over the next 15 seconds to

asystole, lasting 12 seconds. Atropine 1200 [mu].g and 9 mg of ephedrine

were administered and the surgical stimulus was ceased. Chest

compressions were commenced over the patient’s mid thoracic spine

between the scapulae, while preparations to turn him supine were made. A

decrease in [ETCO.sub.2] to 28 mmHg from 37 mmHg was noted during this

episode, but no non-invasive blood pressure measurements were recorded.

The patient’s heart rate improved to 86 min1 following treatment.

Surgery was completed and he recovered uneventfully.

Chest compressions in the prone position, “reverse CPR”,

was first described in 1989 by McNeil (1). Several techniques have been

described since, with application of the compressions either directly

over the thoracic spine or adjacent to the thoracic spine on both sides

(if an incision is present) (2). Counterpressure on the sternum, where a

closed fist is placed between the sternum and the operating table may

assist with focusing compressions over the sternum. When positioned on

the Andrews table, the abdomen hangs free but the thorax rests on a

support pad, enabling thoracic compressions to be performed. The

effectiveness of reverse CPR has been demonstrated in case reports where

invasive blood pressure monitoring has been used (3). These however,

have not involved the prone-kneeling position on an Andrews table.

Profound bradycardia during lumbosacral spinal surgery has been

reported infrequently (4,5). Its mechanism has been described as

resulting from stimulation of afferent parasympathetic nerve endings due

to traction on the dura, causing a reflex-coeliac (vasovagal) reaction4.

Initiating CPR on the prone surgical patient invariably involves turning

the patient supine. Logistically, this can prove difficult during this

time-critical event, as it requires other personnel and another bed.

Operative exposure, patient positioning and cranial fixation may also

impede turning. In these situations, it may be both advisable and

effective to commence CPR in the prone position while preparations are

made to turn the patient supine. In some instances such as the case

reported, the cardiac arrest may transient and turning the patient may

not be necessary.

References

(1.) McNeil E. Re-evaluation of cardiopulmonary resuscitation.

Resuscitation 1989; 18:1.

(2.) Brown J, Rogers J, Soar J. Cardiac arrest during surgery and

ventilation in the prone position: a case report and systematic review.

Resuscitation 2001; 50:233

(3.) Stewart J. Resuscitating an idea: prone CPR. Resuscitation

2002; 54:231

(4.) Deschamps A, Carvalho G. Lumbo-sacral spine surgery and severe

bradycardia (Letter). Can J Anaesth 2004; 51:277; Erratum: Can J Anesth

2004; 51:643

(5.) Mandal N. More on lumbo-sacral spine surgery and bradycardia

(Letter). Can J Anaesth 2004; 51:942

N. DOONEY

Adelaide, South Australia