TY - JOUR
T1 - The incidence of pneumocephalus after supratentorial craniotomy
T2 - Observations on the disappearance of intracranial air
AU - Reasoner, D. K.
AU - Todd, M. M.
AU - Scamman, F. L.
AU - Warner, D. S.
PY - 1994/1/1
Y1 - 1994/1/1
N2 - Background: Pneumocephalus occurs in a variety of clinical settings and has important anesthetic implications, particularly if N2O is used. One common cause of pneumocephalus is a craniotomy or craniectomy, and therefore patients undergoing these neurosurgical procedures may be at increased risk for the development of tension pneumocephalus if N2O is used during a subsequent anesthetic. However, because the rate at which a postoperative pneumocephalus resolves has not been well defined, the duration of this risk period is unknown. Methods: Department of Anesthesia billing codes were used to identify all patients undergoing supratentorial craniotomy between 1986 and 1990. This list was cross-indexed with Department of Radiology data to generate a list of patients who had had a computed tomographic scan of the head performed on or after the day of their surgery. From this list, 240 scans were examined for the presence of intracranial air. The magnitude of pneumocephalus, if present, was ranked as large, moderate, small, or trace. Results: Air was seen in all scans obtained in the first 2 post-operative days. Sixty-six percent of these pneumocephali were judged to be moderate or large. The incidence of pneumocephalus decreased to 75% by postoperative day 7. During the 2nd and 3rd postoperative weeks, the incidence of pneumocephalus decreased to 59.6 and 26.3%, respectively. The size of the pneumocephali also decreased. Still, 11.8% of the scans obtained during the 2nd postoperative week had pneumocephali that were judged to be moderate or large. Conclusions: These data indicate that all patients have pneumocephalus immediately after a supratentorial craniotomy. Although the incidence and size of pneumocephali decrease over time, a significant number of patients have an intracranial air collection large enough to put them at risk for complication if N2O is used during a second anesthetic in the first 3 weeks after the first procedure. This information should be considered in the evaluation of the patient and in the selection of anesthetic agents.
AB - Background: Pneumocephalus occurs in a variety of clinical settings and has important anesthetic implications, particularly if N2O is used. One common cause of pneumocephalus is a craniotomy or craniectomy, and therefore patients undergoing these neurosurgical procedures may be at increased risk for the development of tension pneumocephalus if N2O is used during a subsequent anesthetic. However, because the rate at which a postoperative pneumocephalus resolves has not been well defined, the duration of this risk period is unknown. Methods: Department of Anesthesia billing codes were used to identify all patients undergoing supratentorial craniotomy between 1986 and 1990. This list was cross-indexed with Department of Radiology data to generate a list of patients who had had a computed tomographic scan of the head performed on or after the day of their surgery. From this list, 240 scans were examined for the presence of intracranial air. The magnitude of pneumocephalus, if present, was ranked as large, moderate, small, or trace. Results: Air was seen in all scans obtained in the first 2 post-operative days. Sixty-six percent of these pneumocephali were judged to be moderate or large. The incidence of pneumocephalus decreased to 75% by postoperative day 7. During the 2nd and 3rd postoperative weeks, the incidence of pneumocephalus decreased to 59.6 and 26.3%, respectively. The size of the pneumocephali also decreased. Still, 11.8% of the scans obtained during the 2nd postoperative week had pneumocephali that were judged to be moderate or large. Conclusions: These data indicate that all patients have pneumocephalus immediately after a supratentorial craniotomy. Although the incidence and size of pneumocephali decrease over time, a significant number of patients have an intracranial air collection large enough to put them at risk for complication if N2O is used during a second anesthetic in the first 3 weeks after the first procedure. This information should be considered in the evaluation of the patient and in the selection of anesthetic agents.
KW - Anesthesia: neurosurgical
KW - Anesthetics, gases: nitrous oxide
KW - Brain: intracranial pressure
KW - Complications: pneumocephalus
KW - Neuroanesthesia
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U2 - 10.1097/00000542-199405000-00009
DO - 10.1097/00000542-199405000-00009
M3 - Article
C2 - 8017640
AN - SCOPUS:0028358159
SN - 0003-3022
VL - 80
SP - 1008
EP - 1012
JO - Anesthesiology
JF - Anesthesiology
IS - 5
ER -