[Anesthesia in geriatric patients. The determination of physiological variables for cognitive function in geriatric patients after regional or general anesthesia].
OBJECTIVE
The aim of the present study was to show the influence of the parameters of gas exchange (arterial oxygen pressure paO2, arterial oxygen saturation SatO2) and haemodynamics (arterial systolic and mean blood pressure RRs and MAP) on the restitution of cognitive functions in geriatric patients scheduled for elective hip arthroplasty.


METHODS
A total of 30 patients (70 years, ASA II) were randomized to be operated either in regional anaesthesia (n = 15) or general anaesthesia (n = 15). PaO2 (by capillary blood gas analysis), RRs and MAP (by oscillometry) were measured 15 and 90 minutes after arrival in the recovery unit (t1 and t2), 24 and 72 hours postoperatively (t3 and t4), and cognitive functions were tested. Intraoperatively, throughout the day and the first night after surgery we measured satO2 by continuous pulse oximetry. We recorded MAP and RRs by oscillometry every 3 minutes during the operation and every 15 minutes for the rest of that day and night.


RESULTS
The parameters of gas exchange and haemodynamics did not differ among the groups. PaO2 was significantly reduced in both groups compared to baseline 24 hours postoperatively (t3) and remained low until 72 hours postoperatively (t4). Nearly all cognitive functions were significantly reduced in both groups compared to baseline 15 and 90 minutes after arrival in the recovery unit (t1 and t2), but recovered on the first postoperative day (t3). Both groups kept deficits in verbal memory and reading capacity up to the third postoperative day (t4). There was no correlation between the physiological parameters and the restitution of the tested cognitive functions.


CONCLUSIONS
The restitution of cognitive functions during the first three postoperative days in geriatric patients scheduled for elective hip surgery does not depend on the anaesthetic technique. According to our results regional anaesthesia does not show any advantage for geriatric patients undergoing elective hip arthroplasty.
Dahn
J
J
Institut für Anästhesiologie und Operative Intensivmedizin, Universitätsklinikum Mannheim, Klinikum Mannheim gGmbH.
Oster
M
M
Möltner
A
A
Wöhrle
C
C
Rätzer-Frey
A
A
van Ackern
K
K
Hölzl
R
R
Segiet
W
W
D000368:Aged; D000369:Aged, 80 and over; D000765:Anesthesia, Conduction; D000768:Anesthesia, General; D019644:Arthroplasty, Replacement, Hip; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D011659:Pulmonary Gas Exchange
D010100:Oxygen
Anästhesie bei geriatrischen Patienten. Die Bedeutung physiologischer Variablen für die kognitive Leistungsfähigkeit geriatrischer Patienten nach Regionaloder Allgemeinanästhesie.