Factors Associated With Desaturation in Prehospital Rapid Sequence Intubation in a Helicopter Emergency Medical Service.

OBJECTIVE: Desaturation during prehospital rapid sequence intubation (RSI) is common and is associated with patient morbidity. Past studies have identified oxygen saturations at induction, the grade of laryngoscopy, and multiple attempts to intubate as being associated with desaturation. This study aimed to investigate whether there are other factors, identifiable before RSI, associated with desaturation. METHODS: This was a study of a physician-paramedic critical care team operating as Aeromedical Operations, NSW Ambulance. Prehospital RSIs (using paralysis) were studied retrospectively via patient case notes, monitor data, and an airway database. The review occurred between April 1, 2016, and December 31, 2018. Desaturation was defined as monitor recordings of saturations ≤ 92%. Logistic regression was performed for factors likely to be associated with desaturation. RESULTS: Desaturation occurred in 67 of 350 (19.1%) RSIs. Factors significantly associated with desaturation included male sex, a chest injury, increased weight, and lower saturations pre-RSI. CONCLUSION: Increased weight, chest injuries, and lower oxygen saturations are associated with desaturation at RSI. The variable male sex may be a surrogate for other as-yet unidentified factors.

Mitochondrial DNA mutations in human colonic crypt stem cells.

The mitochondrial genome encodes 13 essential subunits of the respiratory chain and has remarkable genetics based on uniparental inheritance. Within human populations, the mitochondrial genome has a high rate of sequence divergence with multiple polymorphic variants and thus has played a major role in examining the evolutionary history of our species. In recent years it has also become apparent that pathogenic mitochondrial DNA (mtDNA) mutations play an important role in neurological and other diseases. Patients harbor many different mtDNA mutations, some of which are mtDNA mutations, some of which are inherited, but others that seem to be sporadic. It has also been suggested that mtDNA mutations play a role in aging and cancer, but the evidence for a causative role in these conditions is less clear. The accumulated data would suggest, however, that mtDNA mutations occur on a frequent basis. In this article we describe a new phenomenon: the accumulation of mtDNA mutations in human colonic crypt stem cells that result in a significant biochemical defect in their progeny. These studies have important consequences not only for understanding of the finding of mtDNA mutations in aging tissues and tumors, but also for determining the frequency of mtDNA mutations within a cell.