title: Acute respiratory and metabolic acidosis induced by excessive muscle contraction during spinal evoked stimulation.
abstract: Spinal somatosensory evoked potentials (SSEPs) have been used to monitor spinal cord function during corrective scoliosis surgery. We report three cases in which direct epidural stimulation for measurement of SSEPs produced paraspinal muscle contraction, resulting in respiratory and metabolic acidosis. In two of the cases, SSEP-induced acidosis was observed even when only the first twitch of the train-of-four response was detectable after a second dose of muscle relaxant. In one of these two cases, the acidosis was abolished after a sufficient dose of vecuronium to ablate the twitch response. To prevent SSEP-induced respiratory and metabolic acidosis, we recommend that SSEPs should be measured only when profound neuromuscular blockade has been obtained.
authors.affiliation: Department of Anesthesiology, Sapporo Medical University School of Medicine, Hokkaido, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tohdoh
authors.forename: S
authors.initials: S
authors.lastname: Sumita
authors.forename: T
authors.initials: T
authors.lastname: Kawamata
authors.forename: K
authors.initials: K
authors.lastname: Omote
authors.forename: S
authors.initials: S
authors.lastname: Kawana
authors.forename: A
authors.initials: A
authors.lastname: Namiki
mesh_terms: D000138:Acidosis / Q000209:etiology*; D000142:Acidosis, Respiratory / Q000209:etiology / Q000503:physiopathology; D000293:Adolescent; D004558:Electric Stimulation / Q000009:adverse effects; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D008297:Male; D016343:Monitoring, Intraoperative / Q000009:adverse effects*; D009119:Muscle Contraction / Q000502:physiology*; D012600:Scoliosis / Q000601:surgery*