Effect of lumbar epidural anesthesia on ventilatory response to hypercapnia in young and elderly patients.
OBJECTIVE
To examine the influence of age on resting ventilation, arterial blood gas tensions, and the ventilatory response to hypercapnia in lumbar epidural anesthesia.


METHODS
Clinical study using groups of young and elderly patients.


METHODS
Surgical operation center of a university hospital.


METHODS
Seven young (average age 39 years) and seven elderly (average age, 69 years) unpremedicated patients undergoing lower abdominal surgery.


METHODS
Patients were administered lumbar epidural anesthesia with 10 ml of 2% lidocaine.


RESULTS
Resting ventilation, arterial blood gas tensions, and ventilatory response to hypercapnia were measured before and 20 minutes after the block. Regarding the ventilatory response to hypercapnia, the mean slope of the hypercapnic response curve [change in minute ventilation (VE) divided by change in end-tidal partial pressure of carbon dioxide (PETCO2)] increased significantly following the epidural block, by 16% in the young patients and by 23% in the elderly patients, and the mean VE at a PETCO2 of 55 mmHg (VE55) also increased significantly, by 16% in the young subjects and by 26% in the older subjects. These changes in delta VE/delta PETCO2 and VE55 were statistically equivalent between the two age-groups.


CONCLUSIONS
The effects of lumbar epidural anesthesia on resting ventilation, arterial blood gas tensions, and ventilatory response to hypercapnia were not affected by age.
Sakura
S
S
Department of Anesthesiology, Shimane Medical University, Japan.
Saito
Y
Y
Kosaka
Y
Y
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000767:Anesthesia, Epidural; D002245:Carbon Dioxide / Q000097:blood / Q000378:metabolism; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D008012:Lidocaine / Q000097:blood / Q000494:pharmacology; D008161:Lumbosacral Region; D008297:Male; D010100:Oxygen / Q000097:blood; D012119:Respiration / Q000187:drug effects / Q000502:physiology*; D013990:Tidal Volume; D014692:Ventilation-Perfusion Ratio / Q000187:drug effects / Q000502:physiology
D002245:Carbon Dioxide; D008012:Lidocaine; D010100:Oxygen