Systemic and cerebral haemodynamics during craniotomy under mild hypothermia in patients with acute subarachnoid haemorrhage.
BACKGROUND
Mild hypothermia provides cerebral protection against ischaemic insults in various animal models. We compared systemic and cerebral oxygenation between mild hypothermic and normothermic management in 60 patients with acute subarachnoid haemorrhage who underwent clipping of cerebral aneurysms.


METHODS
The temperature in the pulmonary artery was maintained at 36 degrees C in 28 patients and was reduced to 34 degrees C in 32 patients. Parameters in the systemic and cerebral haemodynamics from pulmonary artery and internal jugular vein catheters were compared between the two groups immediately after the induction of anaesthesia (TI). and just before temporary occlusion or aneurysm clipping (T2).


RESULTS
Cardiac index, oxygen delivery index, oxygen consumption index, and oxygen saturation of the jugular bulb were significantly lower at T2 in hypothermic group (H) (2.9 +/- 0.6 L/min/m2, 400.8 +/- 106.3 ml/min x m2, 87.0 +/- 14.8 ml/min x m2, 55.2 +/- 6.6%, respectively) than normothermic group (N) (3.7 +/- 0.6, 521.0 +/- 105.5, 109.9 +/- 21.7, 60.9 +/- 6.6) (p < 0.05). The arterial lactate and arteriojugular difference in oxygen content were significantly higher in H (2.3 +/- 1.3 mmol/L, 6.5 +/- 1.5 ml/dl, respectively) than in N (1.7 +/- 1.0, 5.6 +/- 1.2) (p < 0.05). Arteriojugular differences in carbon dioxide tension and hydrogen ion content were significantly lower at T2 in H (-10.8 +/- 2.1 mm Hg, -6.4 +/- 1.3 nmol/L, respectively) than in N (-8.9 +/- 2.8, -5.3 +/- 1.0) (p < 0.05).


CONCLUSIONS
The balance between oxygen supply and demand systemically and in the brain may worsen during aneurysm surgery for patients with acute subarachnoid haemorrhage under mild hypothermia. Oxygenation of the brain and the whole body should be monitored closely during this surgery, and adequate circulatory assistance is recommended under mild hypothermia.
Sato
K
K
Department of Neuroanesthesia, Kohnan Hospital, Sendai, Japan.
Sato
K
K
Yoshimoto
T
T
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply / Q000378:metabolism*; D002545:Brain Ischemia / Q000517:prevention & control*; D003399:Craniotomy / Q000379:methods*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000379:methods; D002532:Intracranial Aneurysm / Q000150:complications / Q000378:metabolism / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D013345:Subarachnoid Hemorrhage / Q000209:etiology / Q000378:metabolism / Q000601:surgery*; D016896:Treatment Outcome
D010100:Oxygen