Both airway devices had similar insertion success and clinical performance in the simulated difficult airway situation. The authors found less epiglottic downfolding and better fiberoptic view but longer insertion time with the i-gel. Our study shows that both devices are feasible for emergency airway management in patients with reduced neck movement and limited mouth opening.
Background
Persistent postoperative cognitive decline is thought to be a public health problem, but its severity may have been overestimated because of limitations in statistical methodology. This study assessed whether long-term cognitive decline occurred after surgery or illness by using an innovative approach and including participants with early Alzheimer's disease to overcome some limitations.
Methods
In this retrospective cohort study, three groups were identified from participants tested annually at Washington University's Alzheimer Disease Research Center in St. Louis: those with non-cardiac surgery, illness, or neither. This enabled long-term tracking of cognitive function before and after surgery and illness. The effect of surgery and illness on longitudinal cognitive course was analyzed using a general linear mixed effects model. For participants without initial dementia, time to dementia onset was analyzed using sequential Cox proportional hazards regression.
Results
Of the 575 participants, 214 were nondemented and 361 had very mild or mild dementia at enrollment. Cognitive trajectories did not differ among the three groups (surgery, illness, control), although demented participants declined more markedly than nondemented. Of the initially nondemented participants, 23% progressed to a clinical dementia rating greater than zero, but this was not more common following surgery or illness.
Conclusions
The study did not detect long-term cognitive decline independently attributable to surgery or illness nor were these events associated with accelerated progression to dementia. The decision to proceed with surgery in elderly people, including those with early Alzheimer's disease, may presently be made without factoring in the specter of persistent cognitive deterioration.
Hypoxia at the surgical site impairs wound healing and oxidative killing of microbes. Surgical site infections are more common in obese patients. We hypothesized that subcutaneous oxygen tension (P sq O 2 ) would decrease substantially in both obese and non-obese patients following induction of anesthesia and after surgical incision. We performed a prospective observational study that enrolled obese and non-obese surgical patients and measured serial P sq O 2 before and during surgery. Seven morbidly obese and seven non-obese patients were enrolled. At baseline breathing room air, P sq O 2 values were not significantly different (p 5 0.66) between obese (6.8 kPa) and non-obese (6.5 kPa) patients. The targeted arterial oxygen tension (40 kPa) was successfully achieved in both groups with an expected significant increase in P sq O 2 (obese 16.1 kPa and non-obese 13.4 kPa; p 5 0.001). After induction of anesthesia and endotracheal intubation, P sq O 2 did not change significantly in either cohort in comparison to levels right before induction (obese 15.5, non-obese 13.5 kPa; p 5 0.95), but decreased significantly during surgery (obese 10.1, non-obese 9.3 kPa; p 5 0.01). In both morbidly obese and non-obese patients, P sq O 2 does not decrease appreciably following induction of anesthesia, but decreases markedly (33%) after commencement of surgery. Given the theoretical risks associated with low P sq O 2 , future research should investigate how P sq O 2 can be maintained after surgical incision.
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