title: Volatile isoflurane sedation in cerebrovascular intensive care patients using AnaConDa(®): effects on cerebral oxygenation, circulation, and pressure.
abstract: OBJECTIVE
  The anesthetic-conserving device AnaConDa(®), a miniature vaporizer, allows volatile sedation in the intensive care unit (ICU). We investigated the effects of isoflurane sedation on cerebral and systemic physiology parameters in neuromonitored ICU stroke patients.
  
  
  METHODS
  Included in the study were 19 consecutive ventilated patients with intracerebral hemorrhage (12), subarachnoid hemorrhage (4), and ischemic stroke (3) who were switched from intravenous propofol or midazolam to inhalative isoflurane sedation for an average of 3.5 days. During the sedation transition, the following parameters were assessed: mean arterial pressure (MAP), intracranial pressure (ICP), cerebral perfusion pressure (CPP), middle cerebral artery mean flow velocity (MFV) and cerebral fractional tissue oxygen extraction (FTOE), as well as systemic cardiopulmonary parameters and administered drugs.
  
  
  RESULTS
  After the first hour, mean ICP showed an increase of 2.1 mmHg that was not clinically relevant. Likewise, MFV did not change. MAP and CPP, however, decreased by 6.5 and 6.3 mmHg, respectively. FTOE was reduced slightly from 0.24 to 0.21 (p = 0.03). Over an observation period of 12 h, ICP remained stable, while MAP and thus CPP showed distinct decreases (CPP: -10 mmHg at 6 h, p < 0.001; -7.5 mmHg at 12 h, p = 0.005, when compared to preswitch levels) despite a 1.5-fold increase in vasopressor administration.
  
  
  CONCLUSIONS
  We suggest that that it is possible to reach sufficient sedation levels in cerebrovascular ICU patients by applying volatile isoflurane long-term without a relevant increase in ICP, if baseline ICP values are low or only moderately elevated. However, caution should be exercised in view of isoflurane's decreasing effect on MAP and CPP. Multimodal neuromonitoring is strongly recommended when applying this off-label sedation method.
authors.affiliation: Department of Neurology, University of Heidelberg, Heidelberg, Germany. julian.boesel@med.uni-heidelberg.de
authors.forename: Julian
authors.initials: J
authors.lastname: Bösel
authors.forename: Jan C
authors.initials: JC
authors.lastname: Purrucker
authors.forename: Frank
authors.initials: F
authors.lastname: Nowak
authors.forename: Julian
authors.initials: J
authors.lastname: Renzland
authors.forename: Petra
authors.initials: P
authors.lastname: Schiller
authors.forename: Eva Benveniste
authors.initials: EB
authors.lastname: Pérez
authors.forename: Sven
authors.initials: S
authors.lastname: Poli
authors.forename: Benjamin
authors.initials: B
authors.lastname: Brunn
authors.forename: Werner
authors.initials: W
authors.lastname: Hacke
authors.forename: Thorsten
authors.initials: T
authors.lastname: Steiner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D002543:Cerebral Hemorrhage / Q000188:drug therapy*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D007427:Intracranial Pressure / Q000187:drug effects; D007530:Isoflurane / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D018696:Neuroprotective Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D012121:Respiration, Artificial; D020521:Stroke / Q000188:drug therapy*; D013345:Subarachnoid Hemorrhage / Q000188:drug therapy*
chemical_list: D018685:Anesthetics, Inhalation; D006993:Hypnotics and Sedatives; D018696:Neuroprotective Agents; D007530:Isoflurane