Anaesth. Intens. Care (1978), 6, 261
BRIEF REPORT:
ANAESTHETIC MANAGEMENT OF INSULlNOMA A. S. M. LAMONT* AND D. JONES, Royal Hobart Hospital, Tasmania
SUMMARY
A patient having surgical removal of an insulinoma was managed by withholding glucose and monitoring blood glucose intra-operatively.
The technique of withholding glucose and monitoring blood glucose during surgery for insulinoma was first described by McMillan and Scheibe (1951). They suggested that if removal of a functioning islet cell adenoma was followed by a sustained increase in blood glucose level, the surgeon could reasonably presume no other tumours were present. In addition the anaesthetist could readily detect hypoglycemia. CASE HISTORY
A 36 year old male nurse reported that on coming ashore from a fishing boat he felt dizzy, sat down and heard music, in addition he saw animals on the shore varying in size from pinpoint to normal. Subsequently he experienced several similar incidents, associated with fatigue and listlessness. Following extensive investigation a diagnosis of epilepsy was made but despite treatment with anti-epileptic drugs he continued to have attacks of bizarre behaviour. It was several months before he was investigated for a probable insulinoma. This diagnosis was confirmed and he was prepared for surgery. ANAESTHETIC MANAGEMENT
The patient was fasted for operation and an intravenous infusion of 5 % dextrose was suspended two hours prior to surgery. A central • M.B. Ch.B.. D.A. (R.C.S.) F.F.A.R.C.S., Director of Anaesthesia. t M.B., B.S., Registrar. Address for reprints: Dr. A. S. M. Lamont, Department of Anaesthesia, Royal Hobart Hospital, Hobart, Tasmania 7000, Australia. Anaesthesia and lntensi!'e Care, Vo/. VI, No. 3, August, 1978
venous catheter was inserted and its position checked radiologically. Premedication consisted of papaveretum 20 mg and scopolamine 0.4 mg intramuscularly one hour preoperatively. Induction was with thiopentone 450 mg followed by pancuronium 8 mg. Anaesthesia was maintained with 4 litres of nitrous oxide and 2 litres of oxygen supplemented with phenoperidine in divided doses. Methoxyflurane 0.2 % was administered intermittently later in the procedure to supplement the analgesic effect of the phenoperidine. Blood sugar estimations were performed prior to induction and during the operation Dextrostix readings were made every five minutes and laboratory samples every ten minutes (Table 1 ). No Dextrose was given during the operation. TABLE 1
Time
0900 (Pre-induction) 0915 0925 0930 0935 0940 0945 0950 0955 1000 1005 1010 1015 1025 1030
Dextrosfix
80 80 70 100 110 90 100 135 135 135 165 170
Laboratory
79 67 89 86 95
99 138 125 176
I.-Blood sugar levels (mg/lOO ml) as measured by the Dextrostix method and by the laboratory.
TABLE
A. S. M. LA MONT AND D. IONES
262
The blood pressure, pulse and central venous pressure, urinary output and electrocardiograph (E.C.G.) were all monitored during surgery. SURGICAL FINDINGS
At surgery an irregular tumour about 5 centimetres in diameter and reddish brown in colour was found in the tail of the pancreas. The tumour together with the tail of the pancreas was resected. Just proximal to the tail a second yellowish tumour was found and removed; at the time it was thought to be a benign adrenal adenoma. The post operative course was uneventful and blood sugar levels were within the range of 120-150 mg/dl. Nine days post-operatively a fasting blood sugar estimation showed a level of 100 mg/ dl. HISTOLOGY
This confirmed the diagnosis of insulinoma in both tumours removed at surgery.
authors have varied considerably. As an alternative to the nitrous oxide analgesic and relaxant techniques Collella and Vandam (1972 ) , advocated diethyl ether. This was based on the concept of a significant increase in blood glucose in man during ether anaesthesia, probably resulting from hepatic glycogenolysis secondary to increased sympathetic discharge (Green 1973). Hargadon and Ormston (1963) recommended that inhalation anaesthetics other than nitrous oxide should not be used because of their hyperglycemic effects. They also felt that halothane was contra-indicated on account of its hypotensive effect. Bourke (1966) also suggested halothane should be avoided because it increases sensitivity to insulin. Although methoxyflurane might influence a steady and progressive rise in blood sugar levels because of its known hyperglycemic effect, we used it intermittently and in low concentration to supplement the anaesthetic sequence. It did not seem to influence the rise in blood sugar level.
DISCUSSION
In most of the writings on anaesthesia for hyperinsulinism the authors emphasise the recognition and treatment of hypoglycemia in order to prevent cerebral damage. Pramila Chari et al. (1977), stressed the regular intake of glucose five hours prior to the induction of anaesthesia by means of intragastic feeds. In their cases transient attacks of presumed hypoglycemia occurred during handling of the tumour. The management of this case is somewhat different and was based on the concept of monitoring blood glucose levels to detect hypoglycemia and rebound hyperglycemia as indicated by McMillan and Sheibe (1951). A rise in blood sugar should occur in the first 30 minutes after complete removal of the tumour. Failure of the blood sugar to rise steadily suggests the possibility that there is incomplete excision of the lesion, however, this may be an over simplification (De Peyster 1973) . The anaesthetic techniques used by different
REFERENCES
Bourke, A. M. (1906): "Anaesthesia for the surgical treatment of hyperinsulinism". Anaesthesia 21. 239-243. CollelIa l. l., and Vandam, L. D. (1972): "Diethyl Ether for a patient with hyperinsulinism". A nesthesiology, 37, 354-356. De Peyster ( 1968): Cited by: Laroche. G. P. Ferris, D. 0., Priestley, .T. T.. Scholtz, D. A .. Dockerty, M. B.: "Hyperinsulism Surgical Results and Management of Occult Functioning Islet Cell Tumour. Review of 154 cases". Archives of Surgery, 96, 763-771. Greene, N. M. (1963): "Inhalation Anaesthetics and Carbohydrate". Baltimore. Williams and Wilkins Co. Hargadon. .I. 1.. and Ormston, T. O. (1963): "Anaesthesia for excision islet cell tumour of the pancreas", Brit. J. Allae.l'th., 35, 807-810. McMillan, F. L., and Scheibe, l. R. (1951): "Islet Cell tumour of the pancreas", A mer. J. SIlI·g., 82, 759. Pramila, Chari, Pandit, S. K., Kataria, R. N., Hariwir Singh. Baheti, and lyotsna, W. J. G. (1977): "Anaesthetic Management of Insulinoma", Anaesthesia. 32, 261-264.
Allaesrhe.\ill and Jntefl.\i\'e Care, Vol. VI, No. 3,
AUKlBt,
1978
BRIEF REPORT:
ANAESTHETIC MANAGEMENT OF INSULlNOMA A. S. M. LAMONT* AND D. JONES, Royal Hobart Hospital, Tasmania
SUMMARY
A patient having surgical removal of an insulinoma was managed by withholding glucose and monitoring blood glucose intra-operatively.
The technique of withholding glucose and monitoring blood glucose during surgery for insulinoma was first described by McMillan and Scheibe (1951). They suggested that if removal of a functioning islet cell adenoma was followed by a sustained increase in blood glucose level, the surgeon could reasonably presume no other tumours were present. In addition the anaesthetist could readily detect hypoglycemia. CASE HISTORY
A 36 year old male nurse reported that on coming ashore from a fishing boat he felt dizzy, sat down and heard music, in addition he saw animals on the shore varying in size from pinpoint to normal. Subsequently he experienced several similar incidents, associated with fatigue and listlessness. Following extensive investigation a diagnosis of epilepsy was made but despite treatment with anti-epileptic drugs he continued to have attacks of bizarre behaviour. It was several months before he was investigated for a probable insulinoma. This diagnosis was confirmed and he was prepared for surgery. ANAESTHETIC MANAGEMENT
The patient was fasted for operation and an intravenous infusion of 5 % dextrose was suspended two hours prior to surgery. A central • M.B. Ch.B.. D.A. (R.C.S.) F.F.A.R.C.S., Director of Anaesthesia. t M.B., B.S., Registrar. Address for reprints: Dr. A. S. M. Lamont, Department of Anaesthesia, Royal Hobart Hospital, Hobart, Tasmania 7000, Australia. Anaesthesia and lntensi!'e Care, Vo/. VI, No. 3, August, 1978
venous catheter was inserted and its position checked radiologically. Premedication consisted of papaveretum 20 mg and scopolamine 0.4 mg intramuscularly one hour preoperatively. Induction was with thiopentone 450 mg followed by pancuronium 8 mg. Anaesthesia was maintained with 4 litres of nitrous oxide and 2 litres of oxygen supplemented with phenoperidine in divided doses. Methoxyflurane 0.2 % was administered intermittently later in the procedure to supplement the analgesic effect of the phenoperidine. Blood sugar estimations were performed prior to induction and during the operation Dextrostix readings were made every five minutes and laboratory samples every ten minutes (Table 1 ). No Dextrose was given during the operation. TABLE 1
Time
0900 (Pre-induction) 0915 0925 0930 0935 0940 0945 0950 0955 1000 1005 1010 1015 1025 1030
Dextrosfix
80 80 70 100 110 90 100 135 135 135 165 170
Laboratory
79 67 89 86 95
99 138 125 176
I.-Blood sugar levels (mg/lOO ml) as measured by the Dextrostix method and by the laboratory.
TABLE
A. S. M. LA MONT AND D. IONES
262
The blood pressure, pulse and central venous pressure, urinary output and electrocardiograph (E.C.G.) were all monitored during surgery. SURGICAL FINDINGS
At surgery an irregular tumour about 5 centimetres in diameter and reddish brown in colour was found in the tail of the pancreas. The tumour together with the tail of the pancreas was resected. Just proximal to the tail a second yellowish tumour was found and removed; at the time it was thought to be a benign adrenal adenoma. The post operative course was uneventful and blood sugar levels were within the range of 120-150 mg/dl. Nine days post-operatively a fasting blood sugar estimation showed a level of 100 mg/ dl. HISTOLOGY
This confirmed the diagnosis of insulinoma in both tumours removed at surgery.
authors have varied considerably. As an alternative to the nitrous oxide analgesic and relaxant techniques Collella and Vandam (1972 ) , advocated diethyl ether. This was based on the concept of a significant increase in blood glucose in man during ether anaesthesia, probably resulting from hepatic glycogenolysis secondary to increased sympathetic discharge (Green 1973). Hargadon and Ormston (1963) recommended that inhalation anaesthetics other than nitrous oxide should not be used because of their hyperglycemic effects. They also felt that halothane was contra-indicated on account of its hypotensive effect. Bourke (1966) also suggested halothane should be avoided because it increases sensitivity to insulin. Although methoxyflurane might influence a steady and progressive rise in blood sugar levels because of its known hyperglycemic effect, we used it intermittently and in low concentration to supplement the anaesthetic sequence. It did not seem to influence the rise in blood sugar level.
DISCUSSION
In most of the writings on anaesthesia for hyperinsulinism the authors emphasise the recognition and treatment of hypoglycemia in order to prevent cerebral damage. Pramila Chari et al. (1977), stressed the regular intake of glucose five hours prior to the induction of anaesthesia by means of intragastic feeds. In their cases transient attacks of presumed hypoglycemia occurred during handling of the tumour. The management of this case is somewhat different and was based on the concept of monitoring blood glucose levels to detect hypoglycemia and rebound hyperglycemia as indicated by McMillan and Sheibe (1951). A rise in blood sugar should occur in the first 30 minutes after complete removal of the tumour. Failure of the blood sugar to rise steadily suggests the possibility that there is incomplete excision of the lesion, however, this may be an over simplification (De Peyster 1973) . The anaesthetic techniques used by different
REFERENCES
Bourke, A. M. (1906): "Anaesthesia for the surgical treatment of hyperinsulinism". Anaesthesia 21. 239-243. CollelIa l. l., and Vandam, L. D. (1972): "Diethyl Ether for a patient with hyperinsulinism". A nesthesiology, 37, 354-356. De Peyster ( 1968): Cited by: Laroche. G. P. Ferris, D. 0., Priestley, .T. T.. Scholtz, D. A .. Dockerty, M. B.: "Hyperinsulism Surgical Results and Management of Occult Functioning Islet Cell Tumour. Review of 154 cases". Archives of Surgery, 96, 763-771. Greene, N. M. (1963): "Inhalation Anaesthetics and Carbohydrate". Baltimore. Williams and Wilkins Co. Hargadon. .I. 1.. and Ormston, T. O. (1963): "Anaesthesia for excision islet cell tumour of the pancreas", Brit. J. Allae.l'th., 35, 807-810. McMillan, F. L., and Scheibe, l. R. (1951): "Islet Cell tumour of the pancreas", A mer. J. SIlI·g., 82, 759. Pramila, Chari, Pandit, S. K., Kataria, R. N., Hariwir Singh. Baheti, and lyotsna, W. J. G. (1977): "Anaesthetic Management of Insulinoma", Anaesthesia. 32, 261-264.
Allaesrhe.\ill and Jntefl.\i\'e Care, Vol. VI, No. 3,
AUKlBt,
1978
