title: Initial experience with a novel heat-exchanging catheter in neurosurgical patients.
abstract: Even mild hypothermia provides marked protection against cerebral ischemia in animal models. Hypothermia may be of therapeutic value during neurosurgical procedures. However, current cooling systems often fail to induce sufficient hypothermia before the dura is opened. Furthermore, they usually fail to restore normothermia by the end of surgery, thus delaying extubation. We evaluated a new internal heat-exchanging catheter. Eight ASA physical status II-IV patients (29-72 yr) undergoing craniotomy were enrolled. After the induction of general anesthesia, we introduced the SetPoint catheter into the inferior vena cava via a femoral vein. The target core body temperature was 34 degrees C-34.5 degrees C. After reaching the target, core temperature was maintained until the dura was closed. Target core temperature was then set to 37.0 degrees C, and the patient was rewarmed as quickly as possible. Seven patients had a tumor resection, and one had an aneurysm clipped. The core-cooling rate was 3.9 degrees C +/- 1.6 degrees C/h, and the rewarming rate was 2.0 degrees C +/- 0.5 degrees C/h; core temperature was 35.9 degrees C +/- 0.2 degrees C by the end of surgery. Patients were subsequently kept normothermic for 3 h before the catheter was removed. No thrombus or other particulate material was identified on the extracted catheters. None of the patients suffered any complications that could be attributed to the SetPoint system or thermal management.
  
  
  CONCLUSIONS
  Because current systems for inducing therapeutic hypothermia are too slow, we tested an internal counter-current thermal management system during hypothermic neurosurgery. The SetPoint catheter cooled at 3.9 degrees C +/- 1.6 degrees C/h and rewarmed at 2.0 degrees C +/- 0.5 degrees C/h. Catheter-based internal thermal management thus seems to be rapid and effective.
authors.affiliation: Outcomes Research Institute and Department of Anesthesiology, University of Louisville, KY 40202, USA. agdoufas@Louisville.edu
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Doufas
authors.forename: Ozan
authors.initials: O
authors.lastname: Akça
authors.forename: Atul
authors.initials: A
authors.lastname: Barry
authors.forename: David A
authors.initials: DA
authors.lastname: Petrusca
authors.forename: Mohammad-Irfan
authors.initials: MI
authors.lastname: Suleman
authors.forename: Nobutada
authors.initials: N
authors.lastname: Morioka
authors.forename: John J
authors.initials: JJ
authors.lastname: Guarnaschelli
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
mesh_terms: D000328:Adult; D000368:Aged; D002404:Catheterization; D002405:Catheterization, Central Venous / Q000009:adverse effects / Q000295:instrumentation*; D003399:Craniotomy / Q000295:instrumentation*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D014661:Vasoconstriction