Residual Muscle Weakness after Succinylcholine Infusion: Clinical Presentation, Diagnosis and Treatment

Here we report 2 cases of succinylcholine infusion for short surgical procedures, complicated by clinical presentation of upper airway obstruction in the immediate postoperative period, likely due to residual muscle weakness. In both cases, patients were extubated in OR. The presentation of residual muscle weakness in PACU was supported either with oxygen supplement via nasal cannula or with CPAP. No reintubation was needed. Lab work showed decreased pseudocholinesterase level in one of the patients. Literature review does not support an absolute number of total succinylcholine dosage or total administration time of succinylcholine infusion as a reliable predictor of progression into phase II block. Lab test of pseudocholinesterase function is not routinely performed. Therefore it is prudent to apply neuromuscular monitoring during succinylcholine infusion even when the surgery is considered a short procedure.