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Use of propofol (Diprivan) for awake craniotomies: Technical note
Surg Neurol 1992;38:271-2
271
Use of Propofol (Diprivan) for Awake Craniotomies: Technical Note Daniel L. Silbergeld, M.D., Wade M. Mueller, M.D., Peter S. CoUey, M.D., George A. Ojemann, M.D., and Ettore Lettich, R.E.E.G.T. Departments of Neurological Surgery and Anesthesiology, University of Washington Medical Center, Seattle, Washington, and Department of Neurological Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin
Silbergeld DL, MuellerWM, ColleyPS, OjemannGA, LettichE. Use of propofol (diprivan) for awake craniotomies:technicalnote. Surgical Neurol 1992;38:271-2. We describe the use of propofol (Diprivan) to provide patient comfort during the initial stages of awake craniotomies. KEY WORDS: Craniotomy; Epilepsy; Local anesthesia; Propofol
Despite significant advantages to performing selected craniotomies under local anesthetic [7], some neurosurgeons have been reluctant to utilize this technique because of patient discomfort. Although inhalational general anesthetic agents may be employed for short durations, a significant period of time is required following cessation of these agents before functional testing can be reliably performed. I n addition, the use of an endotracheal tube prohibits verbal patient response. Furthermore, administering and reversing an inhalational general anesthetic is technically difficult and potentially dangerous under these circumstances, because patient position limits airway access. We have recently begun using intravenous propofol ([Diprivan, 2,6-diisopropylphenol] Stuart Pharmaceuticals, Wilmington, Delaware) as an adjunctive anesthetic agent during awake craniotomies. Propofol provides excellent patient sedation and analgesia, with minimal side effects and a rapid and smooth recovery of baseline mental abilities [3,6,8]. Propofol is a water-insoluble phenol, chemically distinct from all other intravenous anesthetics [ 1,9]. Propofol is available as an aqueous oil-in-water emulsion containing 10% soybean oil. It has been commercially available in the United States as Diprivan since 1989.
Address reprint requests to: Daniel L. Silbergeld,M.D., Department of Neurological Surgery, RI-20, Universityof Washington Medical Center, 1959 NE PacificStreet, Seattle, Washington98159. Received September 30, 1991; accepted March 9, 1992.
© 1992by ElsevierSciencePublishingCo.,Inc.
Because propofol is rapidly metabolized in the liver and redistributed rapidly, it is short acting, with a duration of effect similar to methohexital (Brevital) [1,9]. Accordingly, awakening from propofol is rapid and is characteristically without excitement. Propofol is generally associated with a low incidence of nausea and vomiting [2,3]. We report the use of intravenous propofol during the initial stages of nine awake craniotomies performed for temporal lobectomies for medically intractable epilepsy. Following cessation of propofol, patients underwent functional testing and electrocorticography (ECoG) without complication.
Clinical Materials and Methods Five men and four women (age range 18-5 3 years, mean 34 years; weight range 44-82 kg, mean 67 kg), all in good general health (ASA I-II), underwent awake craniotomies for temporal lobectomies using techniques previously described [7]. Premedication with fentanyl (50-150 ~g) and droperidol (1.25-2.50 mg) were used in some of the patients without altering the propofol doses or effects. Prior to propofol administration, patients were reminded that they may be somewhat disoriented upon awakening and should try to remember that they are in the operating room. Oxygenation was initiated and maintained via nasal cannulae. An intravenous bolus of 1-2 mg/kg ofpropofol was administered. Sedation was then maintained with intravenous propofol, titrated so that the patient was sedated, but not apneic. It is important to make sure that an adequate level of anesthesia is obtained prior to beginning any potentially painful part of the procedure. Although most patients awaken without difficulty, some may be disoriented upon awakening. Therefore, having control of the head, as provided by a clamp mounted on the skull (such as a clamp used for holding instruments or ECoG recording devices) may be helpful. Duration of propofol use is dependent on the time required for infiltration of local anesthetic and opening 0090-3019/92/$5.00
272
Surg Neurol 1992;38:271-2
o f the craniotomy. In our cases, this varied from 30 to 105 minutes (mean 52 minutes). Propofol dosage is dependent on several factors including age, weight, preexisting diseases, and drug metabolism [1,9]. Total doses we used ranged from 120 to 1000 mg (1.81-10.17 mg/kg). The duration and nature o f recovery was not altered by either the total dose or the duration o f administration. Fifteen to 25 minutes following cessation o f propofol administration, patients underwent functional cortical mapping using techniques previously described [7]. Sensory and m o t o r mapping (n = 9), language mapping (n = 6), and m e m o r y testing (n -- 1) were accomplished without difficulty. T h e intraoperative E C o G was unaltered by the use o f propofol during the earlier stages o f the operation. H o w e v e r , as has been previously reported [4], we have found that the use o f p r o p o f o l during E C o G recording can alter electrical activity, typically with a burst suppression pattern emerging with higher doses o f propofol. T h r e e patients were able to recall the part o f the operative procedure during which propofol was administered, but no patient recalled pain during that time period. Conclusion A complete and rapid recovery from anesthesia is essential for functional testing during awake craniotomies. Furthermore, the intraoperative E C o G may be suppressed with general anesthetics, making the identification o f electrically active cortex more difficult. We have
Silbergeld et al et al
found that the analgesia [5], recovery pattern [3,6], and absence o f hemodynamic changes [2,8] provided by propofol are optimal for these procedures. Although propofol may alter the E C o G if used concomitantly, it can be used up to 20 minutes prior to E C o G recording and for any stage o f the surgery following the ECoG. Though fairly expensive, propofol allows the surgeon to perform awake craniotomies in younger and more difficult patients.
References 1. Cockshott ID. Propofol (Diprivan) pharmacokinetics and metabolism: an overview. Postgrad Med J 1985;61(Suppl 3):45-50. 2. Grant IS, Mackenzie N. Recovery following propofol (Diprivan) anaesthesia--a review of three different anaesthetic techniques. Postgrad Med J 1985;61(Supp! 3):133-7. 3. Herbert M, Makin SW, Bourke JB, Hart EA. Recovery of mental abilities followinggeneral anaesthesia induced by propofol (Diprivan) or thiopentone. Postgrad Med J 1985;61(Suppl 3):132. 4. Hodkinson BP, Frith RW, Mee EW. Propofol and the electroencephalogram. Lancet 1987;8574:1518. 5. McCullochMJ, Lees NW. Assessmentand modificationof pain on induction with propofol (Diprivan). Anaesthesia 1985;40: 1117-20. 6. Noble J, Ogg TW. The effect of propofol (Diprivan) on memory after day case anaesthesia. Postgrad Med J 1985;61(Suppl 3):103-4. 7. Walsh AR, Ojemann GA. Anterior temporal lobectomy. In: Clinical neurosurgery, vol. 38. Baltimore:Williams & Wilkins, in press. 8. Weintranb M, Standish R. Propofol: a new addition to 'short case' anesthesia. Hospitals 1989;24:199-203. 9. White PF. Propofol: pharmacokinetics and pharmacodynamics. Semin Anesth 1988;7(Suppl 1):4-20.
271
Use of Propofol (Diprivan) for Awake Craniotomies: Technical Note Daniel L. Silbergeld, M.D., Wade M. Mueller, M.D., Peter S. CoUey, M.D., George A. Ojemann, M.D., and Ettore Lettich, R.E.E.G.T. Departments of Neurological Surgery and Anesthesiology, University of Washington Medical Center, Seattle, Washington, and Department of Neurological Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin
Silbergeld DL, MuellerWM, ColleyPS, OjemannGA, LettichE. Use of propofol (diprivan) for awake craniotomies:technicalnote. Surgical Neurol 1992;38:271-2. We describe the use of propofol (Diprivan) to provide patient comfort during the initial stages of awake craniotomies. KEY WORDS: Craniotomy; Epilepsy; Local anesthesia; Propofol
Despite significant advantages to performing selected craniotomies under local anesthetic [7], some neurosurgeons have been reluctant to utilize this technique because of patient discomfort. Although inhalational general anesthetic agents may be employed for short durations, a significant period of time is required following cessation of these agents before functional testing can be reliably performed. I n addition, the use of an endotracheal tube prohibits verbal patient response. Furthermore, administering and reversing an inhalational general anesthetic is technically difficult and potentially dangerous under these circumstances, because patient position limits airway access. We have recently begun using intravenous propofol ([Diprivan, 2,6-diisopropylphenol] Stuart Pharmaceuticals, Wilmington, Delaware) as an adjunctive anesthetic agent during awake craniotomies. Propofol provides excellent patient sedation and analgesia, with minimal side effects and a rapid and smooth recovery of baseline mental abilities [3,6,8]. Propofol is a water-insoluble phenol, chemically distinct from all other intravenous anesthetics [ 1,9]. Propofol is available as an aqueous oil-in-water emulsion containing 10% soybean oil. It has been commercially available in the United States as Diprivan since 1989.
Address reprint requests to: Daniel L. Silbergeld,M.D., Department of Neurological Surgery, RI-20, Universityof Washington Medical Center, 1959 NE PacificStreet, Seattle, Washington98159. Received September 30, 1991; accepted March 9, 1992.
© 1992by ElsevierSciencePublishingCo.,Inc.
Because propofol is rapidly metabolized in the liver and redistributed rapidly, it is short acting, with a duration of effect similar to methohexital (Brevital) [1,9]. Accordingly, awakening from propofol is rapid and is characteristically without excitement. Propofol is generally associated with a low incidence of nausea and vomiting [2,3]. We report the use of intravenous propofol during the initial stages of nine awake craniotomies performed for temporal lobectomies for medically intractable epilepsy. Following cessation of propofol, patients underwent functional testing and electrocorticography (ECoG) without complication.
Clinical Materials and Methods Five men and four women (age range 18-5 3 years, mean 34 years; weight range 44-82 kg, mean 67 kg), all in good general health (ASA I-II), underwent awake craniotomies for temporal lobectomies using techniques previously described [7]. Premedication with fentanyl (50-150 ~g) and droperidol (1.25-2.50 mg) were used in some of the patients without altering the propofol doses or effects. Prior to propofol administration, patients were reminded that they may be somewhat disoriented upon awakening and should try to remember that they are in the operating room. Oxygenation was initiated and maintained via nasal cannulae. An intravenous bolus of 1-2 mg/kg ofpropofol was administered. Sedation was then maintained with intravenous propofol, titrated so that the patient was sedated, but not apneic. It is important to make sure that an adequate level of anesthesia is obtained prior to beginning any potentially painful part of the procedure. Although most patients awaken without difficulty, some may be disoriented upon awakening. Therefore, having control of the head, as provided by a clamp mounted on the skull (such as a clamp used for holding instruments or ECoG recording devices) may be helpful. Duration of propofol use is dependent on the time required for infiltration of local anesthetic and opening 0090-3019/92/$5.00
272
Surg Neurol 1992;38:271-2
o f the craniotomy. In our cases, this varied from 30 to 105 minutes (mean 52 minutes). Propofol dosage is dependent on several factors including age, weight, preexisting diseases, and drug metabolism [1,9]. Total doses we used ranged from 120 to 1000 mg (1.81-10.17 mg/kg). The duration and nature o f recovery was not altered by either the total dose or the duration o f administration. Fifteen to 25 minutes following cessation o f propofol administration, patients underwent functional cortical mapping using techniques previously described [7]. Sensory and m o t o r mapping (n = 9), language mapping (n = 6), and m e m o r y testing (n -- 1) were accomplished without difficulty. T h e intraoperative E C o G was unaltered by the use o f propofol during the earlier stages o f the operation. H o w e v e r , as has been previously reported [4], we have found that the use o f p r o p o f o l during E C o G recording can alter electrical activity, typically with a burst suppression pattern emerging with higher doses o f propofol. T h r e e patients were able to recall the part o f the operative procedure during which propofol was administered, but no patient recalled pain during that time period. Conclusion A complete and rapid recovery from anesthesia is essential for functional testing during awake craniotomies. Furthermore, the intraoperative E C o G may be suppressed with general anesthetics, making the identification o f electrically active cortex more difficult. We have
Silbergeld et al et al
found that the analgesia [5], recovery pattern [3,6], and absence o f hemodynamic changes [2,8] provided by propofol are optimal for these procedures. Although propofol may alter the E C o G if used concomitantly, it can be used up to 20 minutes prior to E C o G recording and for any stage o f the surgery following the ECoG. Though fairly expensive, propofol allows the surgeon to perform awake craniotomies in younger and more difficult patients.
References 1. Cockshott ID. Propofol (Diprivan) pharmacokinetics and metabolism: an overview. Postgrad Med J 1985;61(Suppl 3):45-50. 2. Grant IS, Mackenzie N. Recovery following propofol (Diprivan) anaesthesia--a review of three different anaesthetic techniques. Postgrad Med J 1985;61(Supp! 3):133-7. 3. Herbert M, Makin SW, Bourke JB, Hart EA. Recovery of mental abilities followinggeneral anaesthesia induced by propofol (Diprivan) or thiopentone. Postgrad Med J 1985;61(Suppl 3):132. 4. Hodkinson BP, Frith RW, Mee EW. Propofol and the electroencephalogram. Lancet 1987;8574:1518. 5. McCullochMJ, Lees NW. Assessmentand modificationof pain on induction with propofol (Diprivan). Anaesthesia 1985;40: 1117-20. 6. Noble J, Ogg TW. The effect of propofol (Diprivan) on memory after day case anaesthesia. Postgrad Med J 1985;61(Suppl 3):103-4. 7. Walsh AR, Ojemann GA. Anterior temporal lobectomy. In: Clinical neurosurgery, vol. 38. Baltimore:Williams & Wilkins, in press. 8. Weintranb M, Standish R. Propofol: a new addition to 'short case' anesthesia. Hospitals 1989;24:199-203. 9. White PF. Propofol: pharmacokinetics and pharmacodynamics. Semin Anesth 1988;7(Suppl 1):4-20.