Preoperative warming combined with intraoperative skin-surface warming does not avoid hypothermia caused by spinal anesthesia in patients with midazolam premedication.
OBJECTIVE
Inadvertent perioperative hypothermia is common during spinal anesthesia and after midazolam administration. The aim of this study was to evaluate the effects of intraoperative skin-surface warming with and without 45 minutes of preoperative warming in preventing intraoperative and postoperative hypothermia caused by spinal anesthesia in patients with midazolam premedication.


METHODS
Prospective and randomized study at Hospital das Clínicas, Universidade Estadual Paulista, Botucatu.


METHODS
Thirty patients presenting American Society of Anesthesiologists (ASA) physical status I and II who were scheduled for elective lower abdominal surgery were utilized. The patients received midazolam premedication (7.5 mg by intramuscular injection) and standard spinal anesthesia. Ten patients (Gcontrol) received preoperative and intraoperative passive thermal insulation. Ten patients (Gpre+intra) underwent preoperative and intraoperative active warming. Ten patients (Gintra) were only warmed intraoperatively.


RESULTS
After 45 min of preoperative warming, the patients in Gpre+intra had significantly higher core temperatures than did the patients in the unwarmed groups (Gcontrol and Gintra) before the anesthesia (p < 0.05) but not at the beginning of surgery (p > 0.05). The patients who were warmed intraoperatively had significantly higher core temperatures than did the patients in Gcontrol at the end of surgery (p < 0.05). All the patients were hypothermic at admission to the recovery room (T CORE < 36 degrees C).


CONCLUSIONS
Forty-five minutes of preoperative warming combined with intraoperative skin-surface warming does not avoid but minimizes hypothermia caused by spinal anesthesia in patients with midazolam premedication.
D'Angelo Vanni
Simone Maria
SM
Department of Anesthesiology, School of Medicine, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil.
Castiglia
Yara Marcondes Machado
YM
Ganem
Eliana Marisa
EM
Rodrigues Júnior
Geraldo Rolim
GR
Amorim
Rosa Beatriz
RB
Ferrari
Fábio
F
Braz
Leandro Gobbo
LG
Braz
José Reinaldo Cerqueira
JR
D000328:Adult; D000704:Analysis of Variance; D000775:Anesthesia, Spinal / Q000009:adverse effects*; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001831:Body Temperature / Q000187:drug effects / Q000502:physiology; D005260:Female; D006361:Heating / Q000379:methods*; D006801:Humans; D007035:Hypothermia / Q000139:chemically induced / Q000517:prevention & control*; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008874:Midazolam / Q000008:administration & dosage / Q000009:adverse effects*; D011292:Premedication / Q000009:adverse effects; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D012881:Skin Temperature / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
D014151:Anti-Anxiety Agents; D008874:Midazolam