To the Editor:—
Anesthetic procedures are performed regularly in survivors of the 1930s poliomyelitis epidemic, some of whom may have developed postpolio syndrome.1When a patient with postpolio syndrome is scheduled to undergo a procedure requiring anesthesia, anesthesiologists should carefully assess the patient's preoperative status, namely his or her respiratory function, and inquire about swallowing difficulties or history of intolerance to any general or local anesthetic agent. The use of neuromuscular blocking agents in this context remains controversial.1Increased potency of nondepolarizing neuromuscular blocking agents occurring in patients with a history of poliomyelitis has been suggested.2It is also traditionally well accepted that succinylcholine should be avoided in patients with neuromuscular disease to prevent fatal hyperkalemia. Interestingly, however, this assumption has not been based on any specific report regarding the use of succinylcholine in the context of postpolio syndrome.1Hence, we report here the first case of successful use of succinylcholine in a patient with postpolio syndrome who underwent elective cesarean delivery during general anesthesia.
A 39-yr-old woman (height, 150 cm; weight, 65 kg) was scheduled to undergo elective cesarean delivery at 38 weeks of amenorrhea. She presented with postpolio syndrome according to all of the criteria of Mulder et al. 3: a history of paralytic poliomyelitis when she was 1 yr old followed by motoneuron deficit with electromyographic confirmation. She then had a 20-yr period of recovery and functional stability before experiencing gradual and major peripheral muscular fatigue with muscle atrophy of the limbs starting 5 yr ago, for which no other diagnosis was proved. The patient's motor deficit due to polio at that time was isolated paraplegia without respiratory or bulbar weakness. She presented with atrophy and motor deficit of the limbs. She had no respiratory problems, thoracic deformation, or sleep apnea. Her medical history showed a comprised cholecystectomy performed during general anesthesia 25 yr ago, but no information regarding the type of anesthetic agents used was available. Preoperative evaluation showed the absence of criteria predicting difficult intubation. The blood potassium level was 3.4 mm. General anesthesia, versus spinal or epidural anesthesia, was chosen after an extensive risk–benefit discussion focused on either strategy in light of the recent review published in Anesthesiology in 2005.1The patient was carefully informed of this discussion. General anesthesia with awake fiberoptic tracheal intubation was proposed to the patient preferentially to spinal anesthesia because of the possible neurotoxic effects of local anesthetics on the functional motoneurons of the limbs and the lack of symptoms arguing for a central nervous disease, which could have been a relative contraindication to the use of succinylcholine and hence to general anesthesia. However, the patient declined fiberoptic intubation and gave informed consent for general anesthesia with orotracheal intubation. Succinylcholine was therefore chosen because of the lack of absolute contraindication to this agent in the current case1and the patient's full stomach. After a 10-h fasting interval and preoperative medication with oral effervescent cimetidine (400 mg), preoxygenation was performed for 5 min. Anesthesia was induced with propofol (150 mg in 30 s); a reference train-of-four ratio was measured showing four motor responses at the adductor pollicis. Succinylcholine (50 mg) was then given, and the trachea was intubated 1 min later under the Sellick maneuver, with excellent conditions of exposure of the larynx and no response to train-of-four stimulation. Tympanic temperature was recorded every 15 min and kept as close as possible to 37°C by keeping the patient covered with a Bair-Hugger warming blanket (Arizant France, La Ciotat, France) throughout the procedure. Anesthesia was maintained with use of isoflurane (0.6% end-tidal), nitrous oxide (50%/50% in oxygen, vol/vol), and 0.15 μg/kg sufentanil after extraction of the newborn to obtain a Bispectral Index value between 40 and 60. The Apgar score was 9 at 1 min and 10 at 5 min after delivery. Because of the long-acting effect of succinylcholine, no additional injection of a nondepolarizing neuromuscular blocking drug was required despite the long duration of surgery (90 min). The train-of-four measured at the adductor pollicis every 5 min showed full recovery of the four motor responses only 35 min after tracheal intubation. The trachea was extubated uneventfully shortly after skin closure. The patient was transferred to the postanesthesia care unit. Postoperative pain was treated with use of paracetamol, nefopam, nonsteroidal antiinflammatory drugs, and intravenous morphine titration. Only 6 mg intravenous morphine was required on postoperative day 1. Neurologic examination was performed daily from postoperative day 1 to day 5 and did not reveal any abnormal drowsiness, myalgia, or other significant change in comparison with the patient's preoperative status. The full postoperative course was uneventful, and the patient was discharged from the hospital on postoperative day 5.
Our case is the first report demonstrating that succinylcholine may be used safely in patients with postpolio syndrome. In the current case, the choice of general anesthesia with succinylcholine was based on an extensive risk–benefit analysis with discussion of general anesthesia and perimedullar anesthesia. A lack of symptoms suggesting a diagnosis of postpolio-related central disorder syndrome, a normal preoperative blood potassium level (although of limited value in predicting the magnitude of potassium increase due to motor endplate receptor up-regulation), a full stomach with an increased risk of pulmonary aspiration, and a possible harmful effect on residual motoneurons of local anesthetics given by intrathecal injection were the cornerstones to support our decision. One may notice that the dose of succinylcholine that was used (0.8 mg/kg) resulted in a prolonged depressive action on the train-of-four. We do not believe that hypothermia played a role in this case, because great attention was paid to keeping the patient warm during the procedure. We suggest that, more likely, sensitivity to succinylcholine (and probably muscle relaxants) is enhanced in patients with postpolio syndrome, necessitating careful titration and monitoring of muscle relaxants in this context. The prevalence of postpolio syndrome is estimated to be in the hundreds of thousands in the United States.4Overall, we hope that our data will provide useful information for anesthesiologists in their clinical practice.
The authors thank Sebastian Pease, M.D. (Staff Anesthesiologist, Department of Anesthesia and Intensive Care, Beaujon University Hospital, Assistance Publique des Hôpitaux de Paris, Clichy, France), for stylistic help.
*Beaujon University Hospital, Assistance Publique des Hôpitaux de Paris, Clichy, France. email@example.com