title: Anesthesia and subarachnoid intracranial pressure.
abstract: Intracranial pressure (ICP) was continuously monitored by the Richmond technic of Vries and Becker in 17 patients undergoing elective craniotomy. This method entails the placement, underlocal anesthesia, of a hollow screw through the cranium into the subarachnoid space. The screw was connected to a Statham P23Db pressure transducer with heavy vinyl tubing and with pressures recorded on a Beckman Dynograph. The effects of 3 anesthetic technice-halothane, enflurane, and nitrous oxide-narcotic-relaxant-on ICP during induction and maintenance were compared with preinduction control pressures. Control ICP in awake, lightly premedicated patients was 15 plus or minus 10 torr. Mask inductions with halothane and enflurane consistently caused significant increases in ICP from preinduction levels in the absence of excitement or airway obstruction. Induction with nitrous oxide-narcotic-relaxant did not increase ICP. Decreases in ICP following barbiturate administration were noted. Addition of halothane and enflurane to the inspired mixture of patients controlled and hyperventilated with nitrous oxide and oxygen caused consistent increases in ICP. With control hyperventilation (Paco2 25 plus or minus 5 torr), the ICP did not return toward preinduction values within 5 minutes with enflurane and halothane.
mesh_terms: D000769:Anesthesia, Inhalation; D001463:Barbiturates; D001794:Blood Pressure / Q000187:drug effects; D003399:Craniotomy; D004737:Enflurane / Q000494:pharmacology*; D006221:Halothane / Q000494:pharmacology*; D006801:Humans; D007427:Intracranial Pressure / Q000187:drug effects*; D007442:Intubation, Intratracheal; D007828:Laryngoscopy; D008738:Methyl Ethers / Q000494:pharmacology*; D009020:Morphine; D009609:Nitrous Oxide; D010424:Pentobarbital; D011175:Positive-Pressure Respiration; D011229:Preanesthetic Medication; D011674:Pulse / Q000187:drug effects; D012601:Scopolamine; D013346:Subarachnoid Space; D013390:Succinylcholine; D013874:Thiopental / Q000494:pharmacology; D014403:Tubocurarine
chemical_list: D001463:Barbiturates; D008738:Methyl Ethers; D009020:Morphine; D004737:Enflurane; D012601:Scopolamine; D010424:Pentobarbital; D013390:Succinylcholine; D013874:Thiopental; D009609:Nitrous Oxide; D006221:Halothane; D014403:Tubocurarine