Mild Hypothermia as a Protective Therapy during Intracranial Aneurysm Surgery: A Randomized Prospective Pilot Trial

Hindman, Bradley J.; Todd, Michael M.; Gelb, Adrian W.; Loftus, Christopher M.; Craen, Rosemary A.; Schubert, Armin; Mahla, Michael E.; Torner, James C.

doi:10.1097/00006123-199901000-00009

Cited by 182 publications

(60 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This magnitude of effect is proportionately similar to that previously reported in humans at a variety of moderately hypothermic temperatures (3,5,40). The range of temperatures studied in the current experiments is of particular relevance to current clinical trials utilizing induced hypothermia in either perioperative or intensive care settings (3,12,20,34,36,43). Greater reduction in P 50 would be expected in humans subjected to cardiopulmonary bypass and deep or profound hypothermia (13).…”

Section: Discussionsupporting

confidence: 81%

See 1 more Smart Citation

Pharmacological correction of hypothermic P₅₀shift does not alter outcome from focal cerebral ischemia in rats

Wainwright

Sheng²,

Sato³

et al. 2002

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

. Pharmacological correction of hypothermic P 50 shift does not alter outcome from focal cerebral ischemia in rats. Am J Physiol Heart Circ Physiol 282: H1863-H1870, 2002; 10.1152/ajpheart.00863.2001.-Hypothermia decreases the arterial PO 2 at which hemoglobin is 50% saturated (P50), increasing hemoglobin O2-binding affinity. We used RSR13, a synthetic allosteric modifier of hemoglobin that increases P 50, to study the role of altered hemoglobin O2-binding affinity in mild hypothermic neuroprotection. RSR13 (150 mg/kg iv) restored P50 to normothermic values. Rats underwent 70 min of middle cerebral artery occlusion (MCAO) at 30.0, 34.0, or 37.5°C with hemoglobin saturation held at 98-100%. The 34.0°C group received RSR13 or vehicle before ischemia. After 7 days of recovery, infarct volumes were reduced in all hypothermic groups, without evidence of a detrimental effect on infarct size or neurological score as a result of P 50 correction. To examine for a beneficial effect of P50 correction, ischemia duration was increased to 120 min in rats maintained at 34.0°C. Correction of P50 by RSR13 did not alter cerebral infarct sizes or neurological scores. The decrease in P 50, caused by mild hypothermia, could not be associated with infarct size or neurological deficit resulting from ischemic brain hypoxia in rats.brain; allosteric modification; hypothermia; RSR13 IN LABORATORY MODELS of focal and global cerebral ischemia, mild (34.0°C) and moderate (30.0°C) hypothermia have been shown to reduce brain injury (8,14,17,30,31). Although the efficacy of induced hypothermia remains unproven in humans sustaining ischemic brain injury, intense investigation continues with the hope of defining conditions where benefits may be obtained (12,20,34,36,43).Mild hypothermia produces multiple effects on the ischemic brain. Cerebral metabolic rate is modestly reduced (29), as is the accumulation of glutamate in the extracellular space (9, 41). However, the importance of these effects has been questioned (32, 42). In vitro, mild hypothermia reduces calcium uptake by neurons (2, 6). Mild hypothermia has no effect on protein synthesis during early recirculation (4) but hastens recovery of protein synthesis several hours after reperfusion (39) and diminishes membranebound protein kinase C activity in selectively vulnerable regions (10). Hypothermia also reduces the cerebral formation of reactive oxygen species and nitric oxide (18,22,23,26). The frequency of peri-infarct spontaneous depolarizations is also decreased in hypothermic rats (11).Hypothermia exerts another biological effect, the significance of which has not been examined. The PO 2 at which 50% of hemoglobin (Hb) binding sites are occupied by oxygen (P 50 ) is reduced in a temperature-dependent fashion. It can be speculated that this effect on Hb O 2 -binding affinity may be either beneficial or detrimental to the ischemic brain. Because hypothermia increases the affinity of Hb for O 2 , release of O 2 into tissue could be reduced. In contrast, when Hb affinity for O 2 is incre...

show abstract

Section: Discussionsupporting

confidence: 81%

“…Although the efficacy of induced hypothermia remains unproven in humans sustaining ischemic brain injury, intense investigation continues with the hope of defining conditions where benefits may be obtained (12,20,34,36,43).…”

mentioning

confidence: 99%

Pharmacological correction of hypothermic P₅₀shift does not alter outcome from focal cerebral ischemia in rats

Wainwright

Sheng²,

Sato³

et al. 2002

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

show abstract

“…A pilot randomized study of intraoperative hypothermia demonstrated no outcome advantage in patients with UIAs. 251 Subsequent randomized trials have also failed to demonstrate an overall benefit for RIAs. 252 However, both hypothermia and intraoperative burst suppression to reduce metabolic demand are still used selectively by neurosurgeons and neuroanesthesiologists for cerebral protection during aneurysm surgery, especially in the setting of anticipated temporary vessel occlusion.…”

Section: Other Considerations: Intraoperative Factors/ Technical Advamentioning

confidence: 99%

Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms

Thompson¹,

Brown²,

Amin‐Hanjani³

et al. 2015

Stroke

833

352

View full text Add to dashboard Cite

Purpose— The aim of this updated statement is to provide comprehensive and evidence-based recommendations for management of patients with unruptured intracranial aneurysms. Methods— Writing group members used systematic literature reviews from January 1977 up to June 2014. They also reviewed contemporary published evidence-based guidelines, personal files, and published expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulated recommendations using standard American Heart Association criteria. The guideline underwent extensive peer review, including review by the Stroke Council Leadership and Stroke Scientific Statement Oversight Committees, before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee. Results— Evidence-based guidelines are presented for the care of patients presenting with unruptured intracranial aneurysms. The guidelines address presentation, natural history, epidemiology, risk factors, screening, diagnosis, imaging and outcomes from surgical and endovascular treatment.

show abstract

“…35,50 In addition, elevated ICP may worsen other aSAH-related complications and overall prognosis. Elevated intracranial pressure (ICP) is a well-recognized phenomenon in aneurysmal subarachnoid hemorrhage (aSAH) that has been demonstrated to lead to poor outcomes.…”

Section: Raised Icp In Asah Prevalence and Etiologiesmentioning

confidence: 99%

Management of raised intracranial pressure in aneurysmal subarachnoid hemorrhage: time for a consensus?

Alotaibi

Wang

Pasarikovski

et al. 2017

Neurosurgical Focus

View full text Add to dashboard Cite

Elevated intracranial pressure (ICP) is a well-recognized phenomenon in aneurysmal subarachnoid hemorrhage (aSAH) that has been demonstrated to lead to poor outcomes. Despite significant advances in clinical research into aSAH, there are no consensus guidelines devoted specifically to the management of elevated ICP in the setting of aSAH. To treat high ICP in aSAH, most centers extrapolate their treatment algorithms from studies and published guidelines for traumatic brain injury. Herein, the authors review the current management strategies for treating raised ICP within the aSAH population, emphasize key differences from the traumatic brain injury population, and highlight potential directions for future research in this controversial topic.

show abstract

Mild Hypothermia as a Protective Therapy during Intracranial Aneurysm Surgery: A Randomized Prospective Pilot Trial

Cited by 182 publications

References 53 publications

Pharmacological correction of hypothermic P₅₀shift does not alter outcome from focal cerebral ischemia in rats

Pharmacological correction of hypothermic P₅₀shift does not alter outcome from focal cerebral ischemia in rats

Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms

Management of raised intracranial pressure in aneurysmal subarachnoid hemorrhage: time for a consensus?

Contact Info

Product

Resources

About

Mild Hypothermia as a Protective Therapy during Intracranial Aneurysm Surgery: A Randomized Prospective Pilot Trial

Cited by 182 publications

References 53 publications

Pharmacological correction of hypothermic P50shift does not alter outcome from focal cerebral ischemia in rats

Pharmacological correction of hypothermic P50shift does not alter outcome from focal cerebral ischemia in rats

Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms

Management of raised intracranial pressure in aneurysmal subarachnoid hemorrhage: time for a consensus?

Contact Info

Product

Resources

About

Pharmacological correction of hypothermic P₅₀shift does not alter outcome from focal cerebral ischemia in rats

Pharmacological correction of hypothermic P₅₀shift does not alter outcome from focal cerebral ischemia in rats