Elderly patients often receive too much anaesthesia for endoscopy
Elderly patients undergoing ambulatory gastrointestinal procedures often receive inappropriately high doses of anaesthesia at induction, researchers at Yale have found.
A review of the anaesthetic management of patients undergoing upper endoscopy and colonoscopy at Yale School of Medicine found that, even with age-adjusted dosing, significant drops in mean arterial pressure (MAP) occur.
Vicki Bing, a medical student at Yale, and colleagues sought to determine whether induction anaesthetics are dose-adjusted for age and, if they are, whether this results in increased hypotension They examined the anaesthesia records of 799 adults who under-
went non-emergent, ambulatory gastrointestinal procedures at Yale over a six-week period in 2013. They recorded induction doses of propofol and fentanyl, and looked for changes in MAP within 10 minutes of induction. Anaesthetic doses and changes in MAP were compared across age groups (the oldest group aged ≥80 years) and across ASA classes 1 to 4, which indicate severity of illness.
No adjustment in fentanyl dosing for age
The researchers found there was no difference in fentanyl dosing between age groups. Interestingly, mean fentanyl dose increased with increasing ASA class, whereas propofol dosage, in contrast, was significantly different across age groups, with older patients (over 65 years) receiving less drug than younger patients. An exception was patients in ASA classes 1 and 2, in which propofol dosage did not differ between young and old patients. Notably, despite the fact that older patients received lower propofol doses, patients aged 65 and older experienced significantly greater drops in MAP.
Shamsuddin Akhtar, associate professor of anaesthesia at Yale School of Medicine and senior author of the study, said the findings show that anaesthesia providers are more likely to adjust dosing by ASA class than by age. “Sicker patients get a little less anaesthetic,” he said, adding that the next step will be to delve into the pharmacodynamics data for the oldest age group, which is an area not well understood. Akhtar believes they will find that MAP reductions are even greater in that subset.
“We think there are opportunities to decrease the dose, and [clinicians] should not only be looking at ASA class but also age. There’s more room for reducing the dose in the elderly, especially patients above age 80, said Akhtar. “We know the elderly lack the cardiac, respiratory and renal reserves that younger patients have. […] Significant drops in MAP can result in end-organ damage, but they also trigger therapeutic interventions with vasopressors, fluids and so forth that can have negative consequences in patients with minimal reserves. Prevention of these scenarios is better than cure.”
Bing’s group reported their finding at the 2014 annual meeting of the American Society of Anesthesiologists (abstract 3164).
Source: Anesthesiology News