title: Transcutaneous carbon dioxide measurement after craniotomy in spontaneously breathing patients.
abstract: OBJECTIVE
  The purpose of this study was to determine the incidence of postoperative hypercarbia in patients undergoing intracranial neurosurgery. Postoperative hypercarbia is a well-recognized cause of postoperative morbidity.
  
  
  METHODS
  Sixty-four patients undergoing craniotomy were monitored in the first 36 postoperative hours using transcutaneous CO2 monitoring. We collected and analyzed demographic data, complete medical histories and examinations, and details of surgery, anesthesia, and postoperative progress. The accuracy of the transcutaneous CO2 monitoring was evaluated by comparison with arterial blood gas CO2.
  
  
  METHODS
  The "TINA" TCM3 Transcutaneous CO2 Monitor (Radiometer, Copenhagen, Denmark) was used.
  
  
  RESULTS
  Thirty-nine patients (61%) developed no hypercarbia. Nineteen patients (30%) developed mild to moderate hypercarbia (46-59 mm Hg) and six patients (9%) developed severe hypercarbia (60 mm Hg or greater). Statistically significant differences were observed between the severely hypercarbic group and the other two groups combined, as follows: a higher incidence of preoperative and postoperative seizures, a lower average postoperative Glasgow Coma Scale score, a higher incidence of reintubation and ventilation, and a higher degree of intraoperative brain disturbance. Analysis of transcutaneous CO2 measurements and time-matched arterial blood gas CO2 measurements revealed an acceptable accuracy of the transcutaneous method.
  
  
  CONCLUSIONS
  this study demonstrates that, in routine neurosurgical practice, a subgroup of patients are at risk of developing postoperative hypercarbia, which may be more common than is generally recognized and will not usually be detected by routine postoperative monitoring. Transcutaneous CO2 monitoring is a useful technique that may impact management decisions.
authors.affiliation: Department of Neurosurgery, Westmead Centre, New South Wales, Australia.
authors.forename: K J
authors.initials: KJ
authors.lastname: Drummond
authors.forename: M R
authors.initials: MR
authors.lastname: Fearnside
authors.forename: A
authors.initials: A
authors.lastname: Chee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries; D001785:Blood Gas Monitoring, Transcutaneous; D001929:Brain Edema / Q000000981:diagnostic imaging / Q000453:epidemiology; D002245:Carbon Dioxide / Q000097:blood*; D003399:Craniotomy / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010313:Partial Pressure; D011183:Postoperative Complications; D011859:Radiography; D012119:Respiration; D012121:Respiration, Artificial; D019233:Retreatment; D012640:Seizures / Q000453:epidemiology
chemical_list: D002245:Carbon Dioxide