Prolonged Apnoea after Suxamethonium: An Analysis of the First 225 Cases Reported to the Danish Cholinesterase Research Unit
Article first published online: 30 DEC 2008
© 1978 Acta Anaesthesiologica Scandinavica Fonden
Acta Anaesthesiologica Scandinavica
Volume 22, Issue 4, pages 371–380, August 1978
How to Cite
Viby-Mogensen, J. and Hanel, H. K. (1978), Prolonged Apnoea after Suxamethonium: An Analysis of the First 225 Cases Reported to the Danish Cholinesterase Research Unit. Acta Anaesthesiologica Scandinavica, 22: 371–380. doi: 10.1111/j.1399-6576.1978.tb01313.x
- Issue published online: 30 DEC 2008
- Article first published online: 30 DEC 2008
- Received 20 October, accepted for publication 17 November 1977
During the last 4 years, 225 patients have been referred to the Danish Cholinesterase Research Unit following an episode of prolonged apnoea after suxaniethonium.
Fourteen patients (6.2%) were found to have a low serum cholinesterase activity due to an acquired deficiency (for instance, liver disease, chronic debilitating disease or carcinoma).
One hundred and forty-eight patients (65.8%) had an inherited abnormal serum cholinesterase, and 105 of these patients (46.7%) were homozygous for the atypical enzyme (E1 E1a). The mean period of apnoea in this latter group was 92 min (range: 25–240). Seventeen patients (7.6%) were heterozygous for the normal and the atypical enzyme (E1Y E1a), with a mean apnoea period of 25 min (range: 7–60 min). Twelve patients were found to be heterozygous for the atypical and the silent gene (E1a E1s). The mean period of apnoea was 126 rnin (range: 45–210 min). Fourteen patients had other rare genotypes. The longest mean period of apnoea (170 min, range: 70–330) was found in patients homozygous for the silent gene (E1s E1s). The silent gene and the fluoride-resistant gene were found in 8.9% and 2.7% of the patients, respectively.
In 63 patients (28.1%) both the type and quantity of serum cholinesterase were normal. In 34 of these patients (15.2%), the prolonged apnoea was due to other causes; for example, suxamethonium overdose, hyperventilation and central as well as peripheral respiratory depression. However, in the other 29 patients (12.9%), the reason for the prolonged apnoea could not be established. The possibility therefore exists that these cases represent unknown genotypes.