Inadvertent hypothermia is common during spinal anaesthesia. This study was based on the hypothesis that phenylephrine might attenuate core hypothermia by inhibiting core-to-peripheral redistribution of body heat during spinal anaesthesia. In this prospective randomized study, 20 patients who underwent elective orthopaedic surgery under spinal anaesthesia were randomly assigned to receive either normal saline (control group) or continuously-infused phenylephrine 0.5 μg/kg per min (phenylephrine group). Core temperature, heart rate (HR) and mean arterial pressure (MAP) were monitored. Mean ± SE core temperature at the end of surgery was significantly higher in the phenylephrine-treated group compared with the control group (35.9 ± 0.1 °C versus 35.0 ± 0.1 °C, respectively), although there was no significant difference in baseline core temperature (both groups 36.3 ± 0.1 °C). Mean HR and MAP were not significantly different between the two groups. In conclusion, continuously-infused phenylephrine attenuated core hypothermia during spinal anaesthesia without any haemodynamic complications.
KurzASesslerDILenhardtR: Perioperative normothermia to reduce the incidence of surgical-wound infection and shorten hospitalization. Study of Wound Infection and Temperature Group. N Engl J Med1996; 334: 1209–1215.
2.
SchmiedHKurzASesslerDI: Mild hypothermia increases blood loss and transfusion requirements during total hip arthroplasty. Lancet1996; 347: 289–292.
3.
FrankSMFleisherLABreslowMJ: Perioperative maintenance of normothermia reduces the incidence of morbid cardiac events. A randomized clinical trial. JAMA1997; 277: 1127–1134.
4.
FrankSMBeattieCChristophersonR: Epidural versus general anesthesia, ambient operating room temperature, and patient age as predictors of inadvertent hypothermia. Anesthesiology1992; 77: 252–257.
5.
FrankSMShirYRajaSN: Core hypothermia and skin-surface temperature gradients. Epidural versus general anesthesia and the effects of age. Anesthesiology1994; 80: 502–508.
6.
FrankSMNguyenJMGarciaCM: Temperature monitoring practices during regional anesthesia. Anesth Analg1999; 88: 373–377.
7.
SesslerDIPonteJ: Shivering during epidural anesthesia. Anesthesiology1990; 72: 816–821.
8.
FrankSMEl-RahmanyHKCattaneoCG: Predictors of hypothermia during spinal anesthesia. Anesthesiology2000; 92: 1330–1334.
9.
HynsonJMSesslerDIGlostenB: Thermal balance and tremor patterns during epidural anesthesia. Anesthesiology1991; 74: 680–690.
10.
MatsukawaTSesslerDIChristensenR: Heat flow and distribution during epidural anesthesia. Anesthesiology1995; 83: 961–967.
11.
MatsukawaTSesslerDISesslerAM: Heat flow and distribution during induction of general anesthesia. Anesthesiology1995; 82: 662–673.
12.
IkedaTOzakiMSesslerDI: Intraoperative phenylephrine infusion decreases the magnitude of redistribution hypothermia. Anesth Analg1999; 89: 462–465.
13.
BelaniKSesslerDISesslerAM: Leg heat content continues to decrease during the core temperature plateau in humans anesthetized with isoflurane. Anesthesiology1993; 78: 856–863.
14.
CarpenterRLCaplanRABrownDL: Incidence and risk factors for side effects of spinal anesthesia. Anesthesiology1992; 76: 906–916.
15.
PlattnerOIkedaTSesslerDI: Postanesthetic vasoconstriction slows peripheral-to-core transfer of cutaneous heat, thereby isolating the core thermal compartment. Anesth Analg1997; 85: 899–906.
16.
AlturaBMAlturaBTCarellaA: Vascular smooth muscle and general anesthetics. Fed Proc1980; 39: 1584–1591.
17.
MatsukawaTKurzASesslerDI: Propofol linearly reduces the vasoconstriction and shivering thresholds. Anesthesiology1995; 82: 1169–1180.
18.
XiongJKurzASesslerDI: Isoflurane produces marked and nonlinear decreases in the vasoconstriction and shivering thresholds. Anesthesiology1996; 85: 240–245.
19.
VassilieffNRosencherNSesslerDI: Nifedipine and intraoperative core body temperature in humans. Anesthesiology1994; 80: 123–128.
20.
IkedaTSesslerDIKikuraM: Less core hypothermia when anesthesia is induced with inhaled sevoflurane than with intravenous propofol. Anesth Analg1999; 88: 921–924.
21.
IkedaTKazamaTSesslerDI: Induction of anesthesia with ketamine reduces the magnitude of redistribution hypothermia. Anesth Analg2001; 93: 934–938.
22.
RubinsteinEHSesslerDI: Skin-surface temperature gradients correlate with fingertip blood flow in humans. Anesthesiology1990; 73: 541–545.
23.
StøenRSesslerDI: The thermoregulatory threshold is inversely proportional to isoflurane concentration. Anesthesiology1990; 72: 822–827.
24.
OzakiMKurzASesslerDI: Thermoregulatory thresholds during epidural and spinal anesthesia. Anesthesiology1994; 81: 282–288.
25.
LangesaeterERosselandLAStubhaugA: Continuous invasive blood pressure and cardiac output monitoring during cesarean delivery: A randomized, double-blind comparison of low-dose versus high-dose spinal anesthesia with intravenous phenylephrine or placebo infusion. Anesthesiology2008; 109: 856–863.
26.
ShitaraTWajimaZOgawaR: Dobutamine infusion modifies thermoregulation during general anesthesia. Anesth Analg1996; 83: 1154–1159.
27.
Di MariaCARattiganSClarkMG: Vasoconstrictor-mediated thermogenesis present in perfused skeletal muscle but absent from perfused heart. J Therm Biol2002; 27: 151–158.
28.
TongACRattiganSDoraKA: Vasoconstrictor-mediated increase in muscle resting thermogenesis is inhibited by membrane-stabilizing agents. Can J Physiol Pharmacol1997; 75: 763–771.
