192
J. Dent. 1991;
19: 192-l
94
Short Communication
Alfentanil with methohexitone dental anaesthesia
in paediatric
R. But-ties Edinburgh
Dental Hospital,
UK
ABSTRACT Children recovering from intravenous methohexitone anaesthesia given for simple dental extractions frequently cry, or are restless and confused, during emergence from anaesthesia. This is disturbing for parents and other children. In an attempt to resolve this problem various doses of alfentanil(2.5,5.0,7.5 and 10 l&kg) were added to a standard intravenous dose of methohexitone (2 m&g), with the effects being assessed by comparison with a control group who received methohexitone only. The incidence of crying recorded was significantly lower in the group receiving the highest alfentanil supplement (10 &kg), when compared with the incidence in the group given lower doses of alfentanil or methohexitone alone. Among those who cried, there was a significant delay in onset in the high alfentanil dose group. No adverse effects were observed. KEY WORDS:
Paedodontics. General anaesthesia, Drugs
J. Dent. 1991; 1991)
19: 192-194
(Received 10 July 1990;
reviewed 25 September
1990;
accepted 21 January
Correspondence should be addressed to: Dr R. Burtles, 8 Ventnor Terrace, Edinburgh EH9 2BL. UK.
INTRODUCTION The general anaesthetic techniques commonly employed in Edinburgh Dental Hospital are the inhalation of nitrous oxide and halothane in oxygen and the intravenous injection of methohexitone whilst breathing air. Both methods leave minimal residual analgesia and the recovery phase is often characterized by an abrupt awakening frequently accompanied by crying and distress. Such occurrences upset parents and, in situations where the recovery area is also the preoperative area, other children awaiting treatment. It was considered that the addition of an analgesic to the methohexitone might mitigate the above problems. A study of the analgesic efficacy of alfentanil, which is probably the shortest acting narcotic analgesic available (Kay and Pleuvry, 1980) when combined with methohexitone was therefore undertaken to assess the usefulness of this technique in reducing postoperative distress and crying in children presenting for dental extractions under general anaesthesia.
MATERIALS The procedure
AND METHODS was explained
@ 1991 Butterworth-Heinemann 0300-5712/91/030192-03
to the parents Ltd.
and written,
informed consent obtained. Fifty-seven consecutive patients (age range 4-16 years) were entered into the study. Forty-six (81 per cent) of these patients received alfentanil and methohexitone and the remaining 11 (19 per cent) served as controls receiving methohexitone alone. The controls were distributed at random through the trial. The dose of methohexitone was fixed at 2 mg/kg. The dose of alfentanil was set at 2.5 @kg for the first seven cases; doubled to 5 yg/kg for the next 12 cases and then increased to 7.5 ug/kg for the next five cases. The remaining 22 patients received 10 ug/kg alfentanil. All injections were given over 30 s with the patients in the supine position. No inhalation anaesthetics or premeditation were used during this study. Electronic monitoring was not available. A record was made by an assistant using a stop-watch of the times from successful venepuncture to: 1. The end of surgery.
2. 3. 4. 5. 6.
The first movement. Opening the eyes. Spitting out the dental pack. The child’s first positive response The onset of crying, if any.
Any noted.
intraoperative
movement
to orders.
or phonation
was also
Burtles: Alfentanil with methohexitone
Table 1. Details of patients and doses of alfentanil
Age (vr) Sex (M/F) Weight (kg) Alfentanil
Low dose*
8.6 (4.1)
7.6 (3.7) 8/l
3/8 29.4(12.9) 0
6
26.8(12.2) 4.8
High dose9
(Table II).
6.0 (1.8)* 15/7 23.4(8.1) 10
DISCUSSION
dose (&kg) Results given are mean f s.d. *P < 0.01. tn=ll;Sn=24;§n=22.
For analysis the data obtained was divided into that from the control group, the low-dose alfentanil group (2.5, 5.0 and 7.5 yg/kg) and the high-dose alfentanil group (10 pg/kg). Analyses were completed using analysis of variance (ANOVA), unpaired Students t tests, and Chi-squared and Fisher’s exact tests, with significant differences being considered to be present at the 0.05 per cent level.
RESULTS Details of the patients included in each group by age, sex and weight together with details of the mean doses of alfentanil administered are set out in Table 1. Eleven patients (one in the control, four in the low-dose and six in the high-dose group) were recorded as having moved during surgery, but in only one case was this considered to be indicative of inadequate anaesthesia, justifying a small supplement of methohexitone. Phonation occurred in three patients but was not treated. No additional alfentanil was given. In all cases the airway was maintained without difficulty and no changes in colour were noted. There was no case of apnoea and naloxone was not used. No postoperative vomiting occurred and no complaint of nausea was recorded. There were no significant differences in the times recorded for any of the parameters studied, with the
Methohexitone, in common with all other barbiturates, provides no analgesia (Dundee, 1979). A small dose of barbiturate produces a state of hyperalgesia in which increased response to painful stimuli mayoccur(Goodman and Gilman, 1985). If the dose of barbiturate is increased to produce unconsciousness, anaesthesia is said to have been achieved and minor surgery can be undertaken. As the effect wears off, but before consciousness has fully returned, pain may cause crying and distress which may be extreme and require physical restraint until consciousness returns. This is seen most often in young children. Alfentanil is a short-acting narcotic analgesic. Black et al. (1984) found in adults recovering from breast biopsy surgery under general anaesthesia that the analgesic effect of alfentanil was maximal at 4 min, diminished at 10 min and undetectable at 15 min. This analgesic effect was accompanied by some respiratory depression which was maximal at 2 min and still detectable at 15 min. Kay and Pleuvry (1980) found in adult volunteers that alfentanil up to 6.4 pg/kg produced some degree of respiratory depression from 2 to 8 min after dosing. No such effect was detectable at 30 min. In the present study no evidence of respiratory depression was recorded; however, no electronic monitoring was available. Most of the times recorded and used as indices of recovery were longer in the high-dose group than in the other two groups, with only the time to crying being significantly different. The lower mean age of the high alfentanil dose group might have been expected to be associated with a higher incidence of crying and distress; however, the reverse was found suggesting that the alfentanil provided a considerable degree of analgesia.
Table II. Details of times (min) to achieve stages of recovery
Controls t Mean time (min) to: End of surgery First movement Opening of eyes Spitting out pack Response to orders Crying
2.2 4.3 4.4 4.3 6.3 3.9
No. who criedt No. who did not cryt
9 (82%) 2 (18%)
Results shown are mean f s.d. *p< 0.01. ty = 9.09, P = 0.01. tn=ll;$n=24;§n=22.
193
exception of the time to crying in the high-dose group. This was significantly delayed from 3.9 min to 7.4 min (Table II). The number who cried was notably lower in the high-dose group than in the low-dose and control groups
Alfentanil groups Controls t
anaesthesia
(0.9) (1.5)
(1.8) (1.3) (2.8) (1.7)
Alfentanil High dose9 Low dose$
2.3 4.1 4.5 4.6 5.5 4.0
(0.7) (1.0) (1.2) (1.6) (1 .O) (1.8)
19 (79%) 5 (21%)
2.1 4.9 5.0 ;.;
(1.2) (1.7) (1.9) ;;.;I
7:4 (3:4)* 9 (41%) 13 (59%)
194
J. Dent. 1991;
19: No. 3
No adverse effects were noted during the study, but neither pulse oximetry nor capnography were available when this work was carried out. Furthermore, while no changes in lip colour were seen and ventilation seemed well maintained, it is clearly desirable this work be repeated using appropriate monitoring. It is concluded that the observations presented suggest that in the group studied the quality of postoperative analgesia was improved when 2 mg/kg methohexitone was supplemented with 10 ug/kg alfentanil.
Acknowledgements I am most grateful to Dr Ram Prabhu
for carrying
out the
statistical analyses and to Dr Anton advice with the text.
van der Berg for
References Black T. E., Kay B. and Healey T. E. J. (1984) The analgesic effect of a low dose of alfentanii. Anaesthesia 39, 546-548. Dundee J. W. (1979) Intravenous Anaesthetic Agents. London, Arnold, p. 9. Goodman L. and Gilman A. (1985) The Pharmacological Basis of Therapeutics, 7th edn. New York, MacMillan, chap 17, p. 353. Kay B. and Pleuvry B. (1980) Human volunteer studies of alfentanil. Anaesthesia 35, 952-960.
Corrigendum Calcium
hydroxide
in restorative
dentistry
A. Milosevic, Journal of Dentistry, Volume 19, 1991, pages 3-l 3. Readers will be misled by an inaccuracy in the above review article. Under the heading ‘Antibacterial activity’ it is stated in relation to the work by Fisher (1972) that ‘calcium hydroxide/water paste rendered deep caries sterile in 10 occlusal cavities, although bacterial culture of the dentine was not performed.’ It is acknowledged by the author of the review that this statement is incorrect as bacterial culturing of dentine was included in the work repotted by Fisher (1972). Any misunderstanding or inconvenience caused by this error is regretted.
J. Dent. 1991;
19: 192-l
94
Short Communication
Alfentanil with methohexitone dental anaesthesia
in paediatric
R. But-ties Edinburgh
Dental Hospital,
UK
ABSTRACT Children recovering from intravenous methohexitone anaesthesia given for simple dental extractions frequently cry, or are restless and confused, during emergence from anaesthesia. This is disturbing for parents and other children. In an attempt to resolve this problem various doses of alfentanil(2.5,5.0,7.5 and 10 l&kg) were added to a standard intravenous dose of methohexitone (2 m&g), with the effects being assessed by comparison with a control group who received methohexitone only. The incidence of crying recorded was significantly lower in the group receiving the highest alfentanil supplement (10 &kg), when compared with the incidence in the group given lower doses of alfentanil or methohexitone alone. Among those who cried, there was a significant delay in onset in the high alfentanil dose group. No adverse effects were observed. KEY WORDS:
Paedodontics. General anaesthesia, Drugs
J. Dent. 1991; 1991)
19: 192-194
(Received 10 July 1990;
reviewed 25 September
1990;
accepted 21 January
Correspondence should be addressed to: Dr R. Burtles, 8 Ventnor Terrace, Edinburgh EH9 2BL. UK.
INTRODUCTION The general anaesthetic techniques commonly employed in Edinburgh Dental Hospital are the inhalation of nitrous oxide and halothane in oxygen and the intravenous injection of methohexitone whilst breathing air. Both methods leave minimal residual analgesia and the recovery phase is often characterized by an abrupt awakening frequently accompanied by crying and distress. Such occurrences upset parents and, in situations where the recovery area is also the preoperative area, other children awaiting treatment. It was considered that the addition of an analgesic to the methohexitone might mitigate the above problems. A study of the analgesic efficacy of alfentanil, which is probably the shortest acting narcotic analgesic available (Kay and Pleuvry, 1980) when combined with methohexitone was therefore undertaken to assess the usefulness of this technique in reducing postoperative distress and crying in children presenting for dental extractions under general anaesthesia.
MATERIALS The procedure
AND METHODS was explained
@ 1991 Butterworth-Heinemann 0300-5712/91/030192-03
to the parents Ltd.
and written,
informed consent obtained. Fifty-seven consecutive patients (age range 4-16 years) were entered into the study. Forty-six (81 per cent) of these patients received alfentanil and methohexitone and the remaining 11 (19 per cent) served as controls receiving methohexitone alone. The controls were distributed at random through the trial. The dose of methohexitone was fixed at 2 mg/kg. The dose of alfentanil was set at 2.5 @kg for the first seven cases; doubled to 5 yg/kg for the next 12 cases and then increased to 7.5 ug/kg for the next five cases. The remaining 22 patients received 10 ug/kg alfentanil. All injections were given over 30 s with the patients in the supine position. No inhalation anaesthetics or premeditation were used during this study. Electronic monitoring was not available. A record was made by an assistant using a stop-watch of the times from successful venepuncture to: 1. The end of surgery.
2. 3. 4. 5. 6.
The first movement. Opening the eyes. Spitting out the dental pack. The child’s first positive response The onset of crying, if any.
Any noted.
intraoperative
movement
to orders.
or phonation
was also
Burtles: Alfentanil with methohexitone
Table 1. Details of patients and doses of alfentanil
Age (vr) Sex (M/F) Weight (kg) Alfentanil
Low dose*
8.6 (4.1)
7.6 (3.7) 8/l
3/8 29.4(12.9) 0
6
26.8(12.2) 4.8
High dose9
(Table II).
6.0 (1.8)* 15/7 23.4(8.1) 10
DISCUSSION
dose (&kg) Results given are mean f s.d. *P < 0.01. tn=ll;Sn=24;§n=22.
For analysis the data obtained was divided into that from the control group, the low-dose alfentanil group (2.5, 5.0 and 7.5 yg/kg) and the high-dose alfentanil group (10 pg/kg). Analyses were completed using analysis of variance (ANOVA), unpaired Students t tests, and Chi-squared and Fisher’s exact tests, with significant differences being considered to be present at the 0.05 per cent level.
RESULTS Details of the patients included in each group by age, sex and weight together with details of the mean doses of alfentanil administered are set out in Table 1. Eleven patients (one in the control, four in the low-dose and six in the high-dose group) were recorded as having moved during surgery, but in only one case was this considered to be indicative of inadequate anaesthesia, justifying a small supplement of methohexitone. Phonation occurred in three patients but was not treated. No additional alfentanil was given. In all cases the airway was maintained without difficulty and no changes in colour were noted. There was no case of apnoea and naloxone was not used. No postoperative vomiting occurred and no complaint of nausea was recorded. There were no significant differences in the times recorded for any of the parameters studied, with the
Methohexitone, in common with all other barbiturates, provides no analgesia (Dundee, 1979). A small dose of barbiturate produces a state of hyperalgesia in which increased response to painful stimuli mayoccur(Goodman and Gilman, 1985). If the dose of barbiturate is increased to produce unconsciousness, anaesthesia is said to have been achieved and minor surgery can be undertaken. As the effect wears off, but before consciousness has fully returned, pain may cause crying and distress which may be extreme and require physical restraint until consciousness returns. This is seen most often in young children. Alfentanil is a short-acting narcotic analgesic. Black et al. (1984) found in adults recovering from breast biopsy surgery under general anaesthesia that the analgesic effect of alfentanil was maximal at 4 min, diminished at 10 min and undetectable at 15 min. This analgesic effect was accompanied by some respiratory depression which was maximal at 2 min and still detectable at 15 min. Kay and Pleuvry (1980) found in adult volunteers that alfentanil up to 6.4 pg/kg produced some degree of respiratory depression from 2 to 8 min after dosing. No such effect was detectable at 30 min. In the present study no evidence of respiratory depression was recorded; however, no electronic monitoring was available. Most of the times recorded and used as indices of recovery were longer in the high-dose group than in the other two groups, with only the time to crying being significantly different. The lower mean age of the high alfentanil dose group might have been expected to be associated with a higher incidence of crying and distress; however, the reverse was found suggesting that the alfentanil provided a considerable degree of analgesia.
Table II. Details of times (min) to achieve stages of recovery
Controls t Mean time (min) to: End of surgery First movement Opening of eyes Spitting out pack Response to orders Crying
2.2 4.3 4.4 4.3 6.3 3.9
No. who criedt No. who did not cryt
9 (82%) 2 (18%)
Results shown are mean f s.d. *p< 0.01. ty = 9.09, P = 0.01. tn=ll;$n=24;§n=22.
193
exception of the time to crying in the high-dose group. This was significantly delayed from 3.9 min to 7.4 min (Table II). The number who cried was notably lower in the high-dose group than in the low-dose and control groups
Alfentanil groups Controls t
anaesthesia
(0.9) (1.5)
(1.8) (1.3) (2.8) (1.7)
Alfentanil High dose9 Low dose$
2.3 4.1 4.5 4.6 5.5 4.0
(0.7) (1.0) (1.2) (1.6) (1 .O) (1.8)
19 (79%) 5 (21%)
2.1 4.9 5.0 ;.;
(1.2) (1.7) (1.9) ;;.;I
7:4 (3:4)* 9 (41%) 13 (59%)
194
J. Dent. 1991;
19: No. 3
No adverse effects were noted during the study, but neither pulse oximetry nor capnography were available when this work was carried out. Furthermore, while no changes in lip colour were seen and ventilation seemed well maintained, it is clearly desirable this work be repeated using appropriate monitoring. It is concluded that the observations presented suggest that in the group studied the quality of postoperative analgesia was improved when 2 mg/kg methohexitone was supplemented with 10 ug/kg alfentanil.
Acknowledgements I am most grateful to Dr Ram Prabhu
for carrying
out the
statistical analyses and to Dr Anton advice with the text.
van der Berg for
References Black T. E., Kay B. and Healey T. E. J. (1984) The analgesic effect of a low dose of alfentanii. Anaesthesia 39, 546-548. Dundee J. W. (1979) Intravenous Anaesthetic Agents. London, Arnold, p. 9. Goodman L. and Gilman A. (1985) The Pharmacological Basis of Therapeutics, 7th edn. New York, MacMillan, chap 17, p. 353. Kay B. and Pleuvry B. (1980) Human volunteer studies of alfentanil. Anaesthesia 35, 952-960.
Corrigendum Calcium
hydroxide
in restorative
dentistry
A. Milosevic, Journal of Dentistry, Volume 19, 1991, pages 3-l 3. Readers will be misled by an inaccuracy in the above review article. Under the heading ‘Antibacterial activity’ it is stated in relation to the work by Fisher (1972) that ‘calcium hydroxide/water paste rendered deep caries sterile in 10 occlusal cavities, although bacterial culture of the dentine was not performed.’ It is acknowledged by the author of the review that this statement is incorrect as bacterial culturing of dentine was included in the work repotted by Fisher (1972). Any misunderstanding or inconvenience caused by this error is regretted.
