Cardiovascular effects of two different regional anaesthetic techniques for unilateral leg surgery.
BACKGROUND
Cardiovascular function was assessed in 20 ASA I-II patients, scheduled for elective orthopaedic surgery with tourniquet in order to compare the haemodynamic changes induced by unilateral spinal anaesthesia and combined sciatico-femoral nerve block.


METHODS
After baseline measurement of cardiovascular parameters, patients were randomized to receive unilateral spinal anaesthesia or combined sciatico-femoral nerve block. Spinal anaesthesia was obtained by 8 mg of hyperbaric bupivacaine 0.5% slowly injected (speed=0.02 ml s[-1]) through a 25-G Whitacre spinal needle with the bevel orientated towards the dependent side and patients lying on their operated side for 15 min (group S, n=10). Combined sciatico-femoral nerve block was obtained by 7 mg kg(-1) of mepivacaine 2% (group NB, n=10). Haemodynamic variables were recorded 5, 10, 15, and 30 min after anaesthetic injection before surgery was started.


RESULTS
Anthropometric data, duration of surgery and acceptability of anaesthetic techniques were similar in the 2 groups. In 8 patients of group S, spinal block was restricted to the operated side (pinprick test and Bromage scale), while the other 2 patients developed bilateral spinal block after being turned supine. NB patients showed no haemodynamic changes during the study, whereas patients in group S showed a small but significant decrease of mean arterial blood pressure (P<0.002 vs baseline and P<0.04 vs NB), cardiac index (P<0.01 vs baseline and P<0.01 vs NB), and stroke volume index (P<0.01 vs baseline and P<0.01 vs NB).


CONCLUSIONS
Both sciatico-femoral and unilateral spinal blockade provide adequate anaesthesia for unilateral leg surgery with tourniquet. The former technique affects cardiovascular performance less than the latter one.
Fanelli
G
G
Department of Anaesthesiology and Intensive Care, IRCCS H San Raffaele, University of Milan, Italy.
Casati
A
A
Aldegheri
G
G
Beccaria
P
P
Berti
M
M
Leoni
A
A
Torri
G
G
D000368:Aged; D000775:Anesthesia, Spinal / Q000295:instrumentation / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage; D001794:Blood Pressure / Q000187:drug effects; D001827:Body Height; D001830:Body Surface Area; D001835:Body Weight; D002045:Bupivacaine / Q000008:administration & dosage; D002302:Cardiac Output / Q000187:drug effects; D017558:Elective Surgical Procedures; D005267:Femoral Nerve; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007866:Leg / Q000601:surgery*; D008619:Mepivacaine / Q000008:administration & dosage; D008875:Middle Aged; D009339:Needles; D009407:Nerve Block; D017060:Patient Satisfaction; D011187:Posture; D011312:Pressure; D012584:Sciatic Nerve; D013318:Stroke Volume / Q000187:drug effects; D016683:Supine Position; D013997:Time Factors; D014111:Tourniquets
D000779:Anesthetics, Local; D008619:Mepivacaine; D002045:Bupivacaine