Light vs. heavy sedation during mechanical ventilation after oesophagectomy--a pilot experimental study focusing on memory.
BACKGROUND
To assess and compare the feasibility and stressful memories of light vs. heavy sedation during post-operative mechanical ventilation.


METHODS
Randomized clinical trial in one general intensive care unit (ICU) in a Swedish university hospital. Thirty-six adults were randomly assigned to receive either light [Motor Activity Assessment Scale (MAAS) 3-4] or heavy (MAAS 1-2) sedation with continuous i.v. infusion of propofol during post-operative invasive mechanical ventilation after oesophagectomy. The patients were interviewed at the general ward 5 days post-ICU using the ICU Memory Tool and the ICU Stressful Experience Questionnaire, and 2 months post-ICU using the Impact of Event Scale Revised. Patient data and hourly recorded MAAS values were collected after the interviews.


RESULTS
Seventy-four per cent of the 139 MAAS values in the light sedation group (n=18) and 79% of the 142 in the heavy sedation group (n=18) were within the targeted levels, and the median MAAS scores were 3.0 vs. 1.25, respectively. Intention-to-treat analyses showed no significant difference in the prevalence of stressful memories between groups, including endotracheal tube discomfort, presenting wide 95% confidence intervals for the difference in outcome estimates. Excluding the patients with a prolonged ICU stay (n=3), a higher prevalence of delusional memories was found in the heavy sedation group (31% vs. 0%, P=0.04).


CONCLUSIONS
This small randomized-controlled pilot study suggests that a light sedation regimen during short-term post-operative mechanical ventilation after major surgery is feasible without increasing patient discomfort.
Department of Health Sciences, Division of Nursing, Lund University, Lund, Sweden. Karin.Samuelson@med.lu.se
K A M
KA
Samuelson
D
D
Lundberg
B
B
Fridlund
D000368:Aged; D054810:Deep Sedation / Q000706:statistics & numerical data; D016629:Esophagectomy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008568:Memory / Q000187:drug effects*; D010865:Pilot Projects; D012121:Respiration, Artificial