The debate over the optimal paralytic in RSI continues in my view, albeit many consider its over and declared Rocuronium to be the clear winner. My aeromedical service has replaced vecuronium with rocuronium but still kept suxamethonium/succinylcholine, mainly due to familiarity for it in RSI by all our doctors and nurses.
But this months anaesthesia journal reading revealed another gem from Japanese authors
Aya Ikeda, M.D.,* Shiroh Isono, M.D.,† Yumi Sato, M.D.,‡ Hisanori Yogo, M.D.,‡ Jiro Sato, M.D.,§
Teruhiko Ishikawa, M.D.,† Takashi Nishino, M.D.
Anesthesiology ,Sept 2012.
Background: Recent studies suggest advantages of muscle relaxants for facemask ventilation. However, direct effects of muscle relaxants on mask ventilation remain unclear because these studies did not control mechanical factors influencing ventilation. We tested a hypothesis that muscle relaxants, either rocuronium or succinylcholine, improve mask ventilation.
Methods: In anesthetized adult persons with normal upper airway anatomy, tidal volumes during facemask ventilation were measured while maintaining the neutral head and mandible positions and the airway pressures of a ventilator before and during muscle paralysis induced by either rocuronium (n 14) or succinylcholine (n 17). Tidal volumes of oral and nasal airway routes were separately measured with a custom-made oronasal portioning full facemask. Behavior of the oral airway was observed by an endoscope in six additional subjects receiving succinylcholine.
Results: Total, oral, and nasal tidal volumes did not significantly change at complete muscle paralysis with rocuronium. In contrast, succinylcholine significantly increased total tidal volumes at 60 s after its administration (meanSD; 4.22.1 vs. 5.4 2.6 ml/kg, P 0.02) because of increases of ventilation through both airway routes. Abrupt tidal volume increase occurred more through oral airway route than nasal route. Dilation of the space at the isthmus of the fauces was endoscopically observed during pharyngeal fasciculation in all six subjects.
Conclusions: Rocuronium did not deteriorate facemask ventilation, and it was improved after succinylcholine administration in association with airway dilation during pharyngeal fasciculation. This effect continued to a lesser degree after resolution of the fasciculation
OKAY? I am sure some of you are saying : SO WHAT Minh? My take home messages are the attention to fine details in airway management and are reinforced by this article.
- Note the predominant nasal route during face mask ventilation. IMPORTANT to note as placing oral and nasal airways during difficult BVM will help!
- Note how suxamethonium not rocuronium dilated the pharyngeal airway during fasciculation. IMPORTANT TIP – a more OPEN AIRWAY GIVES YOU AN EDGE IN THE CRITICAL INTUBATION
CAVEATS : The study was performed in an elective setting. No airway maneuvers or optimal positioning were performed. Dose of Rocuronium was 0.6mg/kg and Sux 1mg/kg but neuromuscular monitoring was performed until Train of four stimulation response was absent.