Impact of Anesthetic Choice (Sevoflurane Versus Desflurane) on Airway Reflex Recovery in the Context of Antagonized Neuromuscular Block

Summary

Protective airway reflexes may be impaired in the postoperative period, creating the potential for aspiration of gastric contents, even after a patient exhibits appropriate response to command. Because assessment of airway reflex recovery is not possible in an intubated patient, the clinician must make an empiric decision as to when a patient is safe to extubate, and choose a combination of techniques least likely to result in pharyngeal impairment. Adequacy of reversal of neuromuscular block by cholinesterase inhibitors (e.g., neostigmine) is unpredictable, especially in the presence of profound paralysis, and tactile assessment of train-of four and sustained tetanus has shown poor correlation with objective assessments. Protective airway reflexes may also be impaired during early recovery by the anesthetics themselves, even when muscle relaxant has been avoided. In the absence of muscle relaxant the investigators previously demonstrated that patients receiving an anesthetic with higher tissue solubility, sevoflurane showed significantly greater impairment of swallowing up to 14 minutes after response to command compared to patients receiving an anesthetic with lower tissue solubility, desflurane. Therefore, we ask whether the combination of the more soluble anesthetic and the presence of neuromuscular block antagonized by neostigmine may create a multiplicative effect that might further prolong pharyngeal recovery. We plan to randomly assign 100 patients scheduled to undergo surgery with general anesthesia to a standardized anesthetic that includes 1) sevoflurane, rocuronium with 70 µg/kg neostigmine + 14 µg/kg glycopyrrolate antagonism (group S); or 2) desflurane, rocuronium with 70 µg/kg neostigmine + 14 µg/kg glycopyrrolate antagonism (group D). Airway reflex recovery will be judged as adequate by the patient's ability to swallow 20 mL of water without coughing or drooling 5, 10, 15, 20, 30 and 60 minutes after response to command. Anesthetic (sevoflurane or desflurane) will be discontinued after administration of reversal agent and recovery to TOF (train-of-four) ratio of 0.7.

Timeline

Start

2010-08

Primary completion

2012-08

Completion

2013-08

Publications

• Background Sundman E, Witt H, Olsson R, Ekberg O, Kuylenstierna R, Eriksson LI. The incidence and mechanisms of pharyngeal and upper esophageal dysfunction in partially paralyzed humans: pharyngeal videoradiography and simultaneous manometry after atracurium. Anesthesiology. 2000 Apr;92(4):977-84. doi: 10.1097/00000542-200004000-00014.
• Background Sundman E, Witt H, Sandin R, Kuylenstierna R, Boden K, Ekberg O, Eriksson LI. Pharyngeal function and airway protection during subhypnotic concentrations of propofol, isoflurane, and sevoflurane: volunteers examined by pharyngeal videoradiography and simultaneous manometry. Anesthesiology. 2001 Nov;95(5):1125-32. doi: 10.1097/00000542-200111000-00016.
• Background Mckay RE, Large MJC, Balea MC, Mckay WR. Airway reflexes return more rapidly after desflurane anesthesia than after sevoflurane anesthesia. Anesth Analg. 2005 Mar;100(3):697-700. doi: 10.1213/01.ANE.0000146514.65070.AE.
• Background McKay RE, Malhotra A, Cakmakkaya OS, Hall KT, McKay WR, Apfel CC. Effect of increased body mass index and anaesthetic duration on recovery of protective airway reflexes after sevoflurane vs desflurane. Br J Anaesth. 2010 Feb;104(2):175-82. doi: 10.1093/bja/aep374. Epub 2009 Dec 26.
• Background Murphy GS, Szokol JW, Marymont JH, Greenberg SB, Avram MJ, Vender JS. Residual neuromuscular blockade and critical respiratory events in the postanesthesia care unit. Anesth Analg. 2008 Jul;107(1):130-7. doi: 10.1213/ane.0b013e31816d1268.
• Background DePippo KL, Holas MA, Reding MJ. Validation of the 3-oz water swallow test for aspiration following stroke. Arch Neurol. 1992 Dec;49(12):1259-61. doi: 10.1001/archneur.1992.00530360057018.

Drugs

Indications

No indication recorded.