///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-05:00

A rare case of C2 sensory blockade with preserved phrenic nerve function

Abstract Number: SU-20
Abstract Type: Case Report/Case Series

Meghan I Cook M.D.1 ; John C Coffman M.D.2; Kasey Fiorini M.D.3; Bob Small M.D.4

Introduction: High neuroblockade is an important cause of anesthesia-related maternal morbidity and mortality, and requires prompt recognition and management.(1,2) We present a rare case of high sensory blockade up to C2, that remarkably did not result in hypotension, bradycardia, altered mentation or need for intubation.

Case: A healthy 33 year old nulliparous patient at 40 weeks gestation presented in active labor and had uncomplicated epidural catheter placement at L3-4. She had effective labor analgesia for the next three hours, at which point the decision was made to proceed with emergent cesarean delivery due to recurrent late fetal heart rate decelerations. Her epidural was dosed for surgical anesthesia with fentanyl 50mcg and 2% lidocaine with 1:200K epinephrine 20mL, given in divided doses over 5-6 minutes. This resulted in a T10 sensory blockade, judged to be inadequate for cesarean delivery. 3% chloroprocaine 5mL was administered just prior to skin incision. She was also placed on oxygen 3 L/min by nasal cannula, and received prophylactic IV glycopyrrolate 0.2mg and ephedrine 10mg. After incision, she reported difficulty breathing, and was transitioned to hand-assisted ventilation via facemask. She was unable to move her upper extremities or turn her head. However, she was able to speak quietly, initiate breaths, weakly cough, blink her eyes, and move her facial muscles. Testing revealed a C2 sensory blockade to pinprick stimuli. She did not display any hypotension, bradycardia or loss of consciousness. She received IV midazolam 2mg for anxiolysis. Forty-five minutes after the chloroprocaine dose the sensory blockade had regressed to the C3-4 level. Respirations were assisted for a total of one hour, at which point testing revealed a C5-6 sensory level. She was able to resume unassisted ventilation on face mask oxygen 5 L/min. One hour later she had a T2-3 sensory level, demonstrated full grip strength, and was breathing comfortably on nasal cannula oxygen 2L/min. She was then transferred to the recovery area. The remainder of her admission was uncomplicated and she was discharged with her baby on postpartum day 3.

Discussion: High neuroblockade has been associated with unrecognized intrathecal administration of local anesthetic(2) and with spinal anesthesia after failed epidural block,(3) but can also occur with epidural dosing.(2) The phrenic nerve (C3-5) provides motor innervation to the diaphragm, and despite having a C2 sensory blockade she retained at least partial diaphragm function demonstrated by the ability to initiate breaths throughout the procedure. Differential nerve block in which sensory block level is several dermatomes higher than motor blockade may occur with both spinal and epidural anesthesia, though is rarely observed in clinical practice.(4)

1. Obstet Gynecol 2011;117:69-74.

2. Anesthesiology 2009;110:131–9.

3. Int J Obstet Anesth 2005;14:55-7.

4. Anesthesiology 1989; 70: 851-8.

SOAP 2016