(4â7%). In 22 patients the administration of extradural morphine was considered as a major contributory ... depression after intrathecal administration (Davies,.
British Journal of Anaesthesia 1998; 81: 86–93
Br. J. Anaesth. (1982), 54, 479
ADVERSE EFFECTS OF EXTRADURAL AND INTRATHECAL OPIATES: REPORT OF A NATIONWIDE SURVEY IN SWEDEN L. L. GUSTAFSSON, B. SCHILDT AND K. JACOBSEN SUMMARY
The Swedish Society of Anaesthetists conducted a nationwide retrospective survey of clinical experience with extradural and intrathecal opiates. Special interest was focused on the frequency and type of ventilatory depression. The questionnaire was answered by 84 of 93 departments (90%). Up to May 1981 extradural morphine had been given to approximately 6000–9150 patients, extradural pethidine to 220–450 and intrathecal morphine to 90–150 patients. Ventilatory depression requiring treatment with naloxone was reported in 23 patients treated with extradural morphine (0.25–0.40%) and in six given intrathecal morphine (4–7%). In 22 patients the administration of extradural morphine was considered as a major contributory factor for the occurrence of ventilatory depression. Only two of these 22 patients experienced ventilatory depression later than 6 h after the last dose of opiates (s.c., i.m., i.v. or extradural). Patients aged 70 yr or more, those receiving thoracic extradural puncture and those with reduced ventilatory capacity seemed to be overrepresented.
In 1979 it was demonstrated that small doses of morphine given intrathecally and extradurally produced long-lasting relief of chronic and postoperative pain in man (Bahar et al., 1979; Wang, Nauss and Thomas, 1979). The practice of this promising technique to achieve selective spinal analgesia has been hampered by the lack of controlled clinical studies (Editorial, 1980) and by reports of adverse reactions (Editorial, 1980; Reiz and Westberg, 1980; Yaksh, 1981). Pruritus and urinary retention are frequent side-effects (Reiz and Westberg, 1980; Samii, Chauvin and Viars, 1981). An alarmingly high frequency of late respiratory depression after intrathecal administration (Davies, Tolhurst-Cleaver and James, 1980; Gjessing and Tomlin, 1981) and occasionally after extradural morphine (Boas, 1980; Christensen, 1980; Reiz and Westberg, 1980; Gustafsson, Feychting and Klingstedt, 1981) has been published. The Swedish Society of Anaesthetists contacted the departments of anaesthesia in Sweden about the use and safety of extradural and intrathecal opiates for pain relief in clinical practice. The other aim was L. L. GUSTAFSSON, M.D.; K. JACOBSEN, Department of Clinical Pharmacology, Karolinska Institute, Huddinge University Hospital, S-141 86 Huddinge, Sweden. B. SCHILDT, M.D., Department of Anaesthesia, Linköping University Hospital, S-581 85 Linköping, Sweden. Correspondence to L.L.G. 0007-0912/82/050479-08 $01.00
to estimate the frequency and elucidate the presentation of ventilatory depression after administration of extradural opiates to help in identifying patients with an increased risk for this side-effect. MATERIALS AND METHODS
A questionnaire was sent to the head physicians of the 93 departments of anaesthesia in Sweden requesting them to report if they had used extradural or intrathecal opiates up to April 30, 1981. If so, they were asked about: Use of extradural opiates (a) Year and month when the department used extradural opiates for the first time. (b) If the method was still in use, they were requested to report the indications for intra- and postoperative treatment of pain and for treatment of pain in obstetric, cancer or trauma patients. (c) Type and amount of opiates and solutions administered extradurally. (d) The number of patients treated with extradural morphine, pethidine or any other opiates up to April 30, 1981. If exact figures could not be given, approximate data were requested: 1–10, 11–25, 26–50, 51–100, 101–200, 201–500, 501–1000 or more than 1000 patients. © The Macmillan Press Ltd 1982
Citation classic
480 Adverse reactions to extradural morphine We asked about the number of patients who had experienced ventilatory depression requiring naloxone, severe pruritus, neurological sequelae, urinary retention or other adverse reactions. The reported cases of ventilatory depression were followed up by direct contact with the reporting physicians. Special interest was focused on type of operation and anaesthesia and amount of opiates administered during the periods before, during and after operation. Such data and the use of other drugs, were recorded from anaesthetic and postoperative charts. The patients were classified into three groups: patients given extradural morphine (i) within 1 h after anaesthesia, (ii) 1 h or later after anaesthesia and (iii) patients with cancer or trauma. Use of intrathecal opiates Information of the same type as was requested under the previous two headings was asked for. However, the reported cases of ventilatory depres-
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BRITISH JOURNAL OF ANAESTHESIA sion were not followed up by direct contact with the reporting physicians. RESULTS
The requested information was obtained from 84 of the 93 departments (90%). Extradural opiates had been used in 67 departments and intrathecal in 10. Use of extradural opiates The percentage of the 84 departments that had used extradural opiates increased from less than 10% in June 1979 to more than 70% at the end of 1980 (fig. 1). This technique was still in use in 64 of 67 departments. Between 6000 and 9150 patients were treated with extradural morphine, 220–450 with pethidine and none with other opiates. The stated standard dose of morphine for postoperative patients receiving the drug via a lumbar catheter was 2 mg in 17 departments and 4 mg in 37. At the thoracic level 2 mg was used in 17 and 4 mg in 14 hospitals. Indications for using extradural opiates were received from 63 departments. Postoperative pain was widely accepted (83%), followed by trauma (64%), cancer pain (52%), intra- and postoperative pain (35%) and pain of obstetric procedures (6%). Adverse reactions to extradural morphine In 37 of the 67 departments where extradural morphine was used adverse reactions had been observed.
FIG. 1. The cumulative number of departments of anaesthesia in Sweden (n:84) where extradural opiates were administered from 1977 to May 1981.
Ventilatory depression. Twenty-three instances of ventilatory depression requiring naloxone were reported from 15 departments. The administration of extradural morphine was considered as a major or contributory reason for the depression in 22 (tables I–III, unlikely for patient No. 23). Only three of the 22 patients did not receive opiates additional to extradural morphine in the periods during or after operation (patients Nos 12, 14, 16). Ten of them were aged 70 yr or more and 10 had thoracic injections. The majority of the cases of ventilatory depression occurred soon after administration of extradural morphine (fig. 2). Seven of 22 patients had depression later than 6 h after the last extradural dose of morphine. Depression more than 6 h after the last dose of opiate (as i.v., i.m., s.c. or extradural) was seen in only two patients (fig. 2).
?
Th8–9
Th9–10 Lumbar
70
70 70
70 75
77
78
4
5 6
7 8
9
10
Th8–9
Th9–10
L3–4
52 58
2 3
Lumbar
Level of catheter
27
Age (yr)
1
Patient
Neuroleptanaesthesia.
Low doses of opiates during total gastrectomy.
4 mg 3 within 7 h, first dose 0.5 h after anaesthesia. Repeated doses on 1st and 2nd postop. day.
Morphine 2 mg 25 min after anaesthesia.
Low doses of opiates as premedication and during operation.
Neuroleptanaesthesia.
Probably 5 mg of morphine within 30 min after the extradural dose.
In low doses as premedication and during bronchoscopy.
Neuroleptanaesthesia
Parenteral opiates
Morphine 20 mg 30–60 min after Anaesthesia.
2 mg immediately after anaesthesia.
Probably 2 mg immediately after anaesthesia.
4 mg × 3 within 19 h, last dose immediately before bronchoscopy.
4 mg immediately after anaesthesia.
Extradural morphine
Ventilatory depression induced by extradural morphine given early after neuroleptanaesthesia.
Ventilatory depression induced by concomitant use of extradural and parenteral morphine in early postop. period.
Ventilatory depression induced by concomitant use of extradural and parenteral opiates in a patient with chronic bronchitis.
Ventilatory depression induced by extradural morphine given early after neuroleptanaesthesia.
Comment
Ventilatory depression 3 h after extradural dose. Naloxone given once.
Ventilatory depression induced by extradural morphine given early after neuroleptanaesthesia.
Ventilatory depression Late ventilatory depression 8 h after last after repeated doses of extradural dose. extradural morphine. Naloxone administered twice within 1.5 h.
Ventilatory depression Late ventilatory depression after a high requiring naloxone 12 h extradural dose of morphine. after extradural dose. After 6 h, 6–10 b.p.m.
Ventilatory depression within 30 min after extradural morphine. Naloxone given once.
Ventilatory depression within 30 min after parenteral morphine. Naloxone given once.
Ventilatory depression 5 h after last dose of extradural morphine. Naloxone given once.
Ventilatory depression within 30 min after extradural morphine. Naloxone given once.
Clinical course
TABLE I. Patients with ventilatory depression (extradural morphine given within 1 h after anaesthesia) (n:10)
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ADVERSE EFFECTS OF SPINAL OPIATES 481
L1–2
49
66
68
70
70
75
75
78
79
11
12
13
14
15
16
17
18
19
L3–4
Th7–8
L2–3
Small doses of opiates during operation, morphine 10 mg s.c. 3 h after last extradural dose.
2 mg 3 within 1 h, first dose 2 h after anaesthesia.
3 mg 7 h after anaesthesia.
Morphine 5 mg 10 and 20 h after anaesthesia.
Morphine 2 mg 5 h after anaesthesia.
4 mg about 4 h after anaesthesia.
Morphine 5 mg 1 h after anaesthesia.
Small doses of opiates as premedication and 10.5 h after anaesthesia.
0.8 mg of leptanal during op. of aortic aneurysm.
Small dose of opiate as premedication and 10 mg of morphine s.c. 3 h after extradural morphine.
None except a small dose as premedication.
A moderate dose of a parenteral opiate about 8 h after extradural dose.
Small dose of opiate as premedication.
None, except a small dose as premedication.
4 mg 2 within 3 h, first dose 7 h after anaesthesia.
2 mg 2.5 and 12.5 h after anaesthesia.
1.2 mg of leptanal during thoracotomy, moderate doses of opiate i.m. 2.5 and 6 h after anaesthesia.
Parenteral opiates
4 mg 5 h after anaesthesia.
Extradural morphine
Ventilatory depression 8 h after the first extradural dose of morphine and induced by concomitant use of extradural and parenteral morphine.
Ventilatory depression 3 h after a repeated dose of extradural morphine.
Ventilatory depression after concomitant use of extradural and parenteral opiates in a patient with dura perforation.
Comment
Ventilatory depression 7.7 h after extradural morphine. Naloxone given four times within 3 h.
Ventilatory depression requiring naloxone once 6 h after last dose of extradural morphine.
Ventilatory depression 9 h after the extradural dose. Naloxone repeated twice within 4 h.
Ventilatory depression requiring naloxone 6 and 9 h after the dose.
Ventilatory depression about 9 h after the extradural and 1 h after a parenteral dose of opiate.
Ventilatory depression induced by concomitant use of extradural and parenteral opiates in a septic patient.
Ventilatory depression after two repeated injections of extradural morphine.
Ventilatory depression after concomitant use of extradural and parentoral morphine.
Ventilatory depression 6 and 9 h after a single extradural dose of morphine.
Ventilatory depression induced by concomitant use of extradural and parenteral opiates.
Ventilatory depression 4 Ventilatory depression after and 4.3 h after second dose. repeated small doses of extradural Naloxone given twice within morphine. 20 min.
Ventilatory depression 5h after parenteral morphine. Naloxone given once.
Ventilatory depression 3 h after last extradural dose. Naloxone given once.
Ventilatory depression 6.5 h after extradural morphine and 2 h after last parenteral dose of opiate. Dura perforation (L2–L3).
Clinical course
482
Lumbar
Lumbar
Thoracic
Th7–8
L3–4
Level of catheter
Age Patient (yr)
TABLE II. Patients with ventilatory depression (extradural morphine given 1 h or later after anaesthesia (n=9). Patient No. 13 reported by Gustafsson, Feychting and Klingstedt (1981); No. 14 by Reiz and Westberg (1980); No. 18 by Modig and Paalzow (1981)
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Age (yr)
55–60
68
72
75
Patient
20
21
22
23
Lumbar
Thoracic
Thoracic
Thoracic
Level of catheter
Two high doses of parenteral opiates 1–2 h before extradural morphine.
Day 3: single doses of parenteral opiates. Days 8–11: methadone orally, doses not known.
Day 1: 2 mg 2, sacral route. Days 2–3: 2 mg 3, lumbar route. Days 4–11: 1 mg 3.
During 4 h before extradural morphine, high doses of parenteral opiates to treat pain caused by rib fractures.
24 h before extradural morphine, moderate doses of opiates in parenteral form because of rib fractures.
Parenteral
Morphine 2 mg
Morphine 2 mg
Morphine 2 mg
Extradural morphine
Day 11 unconscious, ventilatory depression, one dose of naloxone. After cessation of extradural and oral doses of opiates, pain free for 1 week.
Within 30 min after extradural morphine, ventilatory depression. Naloxone given once.
Within 30 min after extradural morphine, ventilatory depression. Naloxone given once.
Within 30 miin after extradural morphine, ventilatory depression. Naloxone given once.
Clinical course
Ventilatory depression induced by accumulation of methadone in a patient concomitantly treated with extradural morphine.
Ventilatory depression after a small extradural dose of morphine in a patient given repeated systemic doses of opiates and with multiple rib fractures.
Ventilatory depression after a small extradural dose of morphine in a patient given repeated systemic doses of opiates and with multiple rib fractures.
Ventilatory depression after a small extradural dose of morphine in a patient given moderate systemic doses of opiates and with multiple rib fractures.
Comment
TABLE III. Patients with cancer or trauma experiencing ventilatory depression after extradural morphine (n:4)
90 British Journal of Anaesthesia
ADVERSE EFFECTS OF SPINAL OPIATES 483
Citation classic 484
91 BRITISH JOURNAL OF ANAESTHESIA plasma were normal. The symptoms disappeared within 5–10 min without treatment. Use of intrathecal opiates Of the 10 departments in which intrathecal morphine was used only three were still using the method. Between 90 and 150 patients had been treated. Six departments had observed adverse effects, the most frequent being ventilatory depression. After 0.8–2.0 mg of extradural morphine before cholecystectomy or total hip replacement, six of 32 patients developed PCO2 greater than 7 kPa more than 8 h after anaesthesia. Five of these patients received naloxone. In 10 of the 12 that underwent cholecystectomy the lungs were artificially ventilated for at least 1.5 h after operation. (These 32 patients have been reported by Gjessing and Tomlin (1981).) One patient undergoing transvesical prostatectomy developed ventilatory depression 8 h after morphine 4 mg. He required repeated doses of naloxone for 8 h and thereafter artificial ventilation for another 12 h.
FIG. 2. Hours between the administration of the last dose of extradural morphine (upper legend) and the last dose of opiates (s.c., i.m., i.v. or extradural) (lower legend) and the occurrence of ventilatory depression requiring naloxone (22 patients).
Severe pruritus. Severe pruritus after extradural morphine was reported by 18 departments. Six reported a frequency less than 2%, two between 2 and 5% and six a frequency greater than 5%. Urinary retention. The stated frequency of patients requiring bladder catheterization varied from 0.3 to 25% with a median value of 10%. Other adverse effects. Neurological sequelae after administering morphine were not observed. Reports of single patients experiencing nausea or vomiting euphoria, anxiety or hallucinations were obtained from 11 departments. One patient, 78 yr of age, underwent transurethal diathermy resection of the prostate under extradural anaesthesia with mepivacaine. Three hours after anaesthesia he was given a single dose of morphine 2 mg. Ten to 20 minutes after that injection the patient hallucinated, shivered and became unconscious. The respiratory rate, arterial pressure and heart rate, and the electrolyte concentrations in
DISCUSSION
In 1976 a study on the effectiveness of intrathecal morphine for relief of experimental pain in rats was published (Yaksh and Rudy, 1976). This report initiated a series of trials in man in which long lasting pain relief (24–36 h) was observed after small doses of extradural or intrathecal morphine (Bahar et al., 1979; Wang, Nauss and Thomas, 1979). The use of these methods spread rapidly (Editorial, 1980) and became clinically accepted long before data from controlled studies were published. Our survey further supports the impression of widespread use of these methods in clinical practice. Three years after publication of the original animal study (Yaksh and Rudy, 1976) a majority of the departments of anaesthesia in Sweden had used opiates extradurally. The standard dose of morphine for extradural use was similar among different departments with a tendency to use smaller doses when the drug was given at the thoracic level. It is, however, not known if it is optimal to treat different postoperative pain conditions with the same standard dose. The infrequent use of morphine extradurally for obstetric pain may be attributed to the disappointing clinical results (Husemeyer, O’Connor and Davenport, 1980; Nybell-Lindahl et al., 1981). Our results un-
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British Journal of Anaesthesia
ADVERSE EFFECTS OF SPINAL OPIATES derline the necessity to perform controlled clinical studies to define the dose and schedule of administration of morphine extradurally under different pain conditions. Late ventilatory depression was reported in 4–7% of patients treated with intrathecal morphine. Higher figures have been reported in prospective studies (Davies, Tolhurst-Cleaver and James, 1980; Gjessing and Tomlin, 1981). Interestingly, in one recent study none of 440 patients developed ventilatory depression when 0.3 or 0.4 mg of morphine was administered intrathecally for postoperative pain relief (King et al., 1981). Thus, it may be possible to decrease the occurrence of ventilatory depression by administering smaller doses. This is the largest survey so far reported on ventilatory depression after extradural morphine. This potentially life-threatening side-effect was reported in 0.25–0.40% of the patients in our sample. However, this figure is certainly an underestimate as the study was retrospective. Nine of the 22 patients who developed ventilatory depression within 1 h after the last dose of extradural morphine received both extradural and systemic doses of opiates. Even if the concentration of morphine is reported to be small in plasma after extradural administration, it may induce ventilatory depression when a systemic dose of opiate is administered concomitantly (Weddel and Ritter, 1981). Five of seven patients who developed ventilatory depression later than 6 h after the last dose of extradural morphine (patients Nos 11, 13, 15, 17, 19) received systemic doses of opiates also. Restricted use of systemic opiates when patients are treated with extradural morphine may reduce the risk of this dangerous late ventilatory depression (Boas, 1980; Reiz and Westberg, 1980; Gustafsson, Feychting and Klingstedt, 1981). Other risk factors seemed to be an age of 70 yr or more, impaired respiratory function (patients Nos 3, 20–22) and thoracic administration. Only two of 22 patients developed depression later than 6 h after opiate administered by any route. In these cases (patients Nos 8, 17) high doses of morphine were given (tables I, II). This indicates that the extradural administration of morphine is reasonably safe if certain clinical factors are taken into consideration. More than 6 h after the last opiate administration (s.c., i.m., i.v. or extradural), the risk of ventilatory depression was greatly reduced. This does not mean that it is safe to give a further dose of opiate systemi-
485 cally more than 6 h after the last dose of extradural morphine. One patient developed respiratory depression when morphine was given systemically 8 h after the last extradural dose. ACKNOWLEDGEMENTS
This study was supported by grants from the National Corporation of Swedish Pharmacies and the Karolinska Institute. We are grateful to the Swedish departments of anaesthesia for reporting their experience of extradural and intrathecal opiates. Drs I. Amér, S. Arnér, O. A. Bodén, K. Bergqvist, S. Dahl, U. Enander, B. Feychting, J. Gjessing, L. Mandaus, J. Modig, R. Nilzén, T. Nolin, G. Nordberg, J. Olaisson, N. Rawal, S. Reiz and H. Samuelsson are greatly acknowledged for giving clinical data of their patients. Mrs Jeannette Korobko and Miss Karen McManus provided expert secretarial assistance. REFERENCES
Bahar, M., Olshwang, D., Magora, F., and Davidson, J. T. (1979). Epidural morphine in treatment of pain. Lancet, 1, 527. Boas, R. A. (1980). Hazards of epidural morphine. Anaesth. Intens. Care, 8, 377. Christensen, V. (1980). Respiratory depression after extradural morphine. Br. J. Anaesth. 52, 841. Davies, G. K., Tolhurst-Cleaver, C. L., and James, T. L. (1980). CNS depression from intrathecal morphine. Anesthesiology, 52, 280. Editorial. (1980). Epidural opiates. Lancet, 1, 962. Gjessing, J., and Tomlin, P. J. (1981). Postoperative pain control with intrathecal morphine. Anaesthesia, 36, 268. Gustafsson, L. L., Feychting, B., and Klingstedt, C. (1981). Late respiratory depression after concomitant use of morphine epidurally and parenterally. Lancet, 1, 892. Husemeyer, R. P., O’Connor, M. C., and Davenport, H. T. (1980). Failure of epidural morphine to relieve pain in labour. Anaesthesia, 35, 161. King, G. H., Mok, M. S., Steen, S. N., and Lippman, M. (1981). Relief of postoperative pain with low doses of intrathecal morphine. Abstract no. 147 from Third World Congress on Pain. Pain (Suppl. I). Modig, J., and Paalzow, L. (1981). A comparison of epidural morphine and epidural bupivacaine for postoperative pain relief. Acta Anaesthesiol. Scand., 25, 437. Nybell-Lindahl, G., Carlsson, C., Ingemarsson, I., Westgren, M., and Paalzow, L. (1981). Maternal and fetal concentrations of morphine after epidural administration during labor. Am. J. Obstet.Gynecol., 139, 20. Reiz, S., and Westberg, M. (1980). Side effects of epidural morphine. Lancet, 1, 203. Samii, K., Chauvin, M., and Viars, P. (1981). Postoperative spinal analgesia with morphine. Br. J. Anaesth., 53, 817. Wang, J. K., Nauss, L. A., and Thomas, J. E. (1979). Pain relief by intrathecally applied morphine in man. Anesthesiology, 50, 149. Weddel, S. J., and Ritter, R. R. (1981). Serum levels following epidural administration of morphine and correlation with relief of postsurgical pain. Anesthesiology, 54, 210. Yaksh, T. L. (1981). Spinal opiate analgesia: characteristics and principles of action. Pain, 11, 293. —— Rudy, T. A. (1976). Analgesia mediated by a direct spinal action of narcotics. Science, 191, 1537.
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EFFETS DELETERES DES OPIACES ADMINISTRES PAR VOIE SOUS-ET PERIDURALE: RESULTATS D’UNE ENQUETE NATIONALE EN SUEDE
RESUME
La Société Suédoise d’Anesthésiologie a mené une enquête nationale rétrospective sur l’expérience clinique de l’utilisation sous- et péridurale des opiacés. Une attention toute particulière s’est portée sur la fréquence et le type de la dépression respiratoire. Quatre-vingt-quatre-départements sur 93 ont répondu au questionnaire (90%). Jusqu’au mois de mai 1981, de la morphine a été administrée par voie péridurale à environ 6000–9150 patients, de la péthidine par voie péridurale à 220–450 patients et de la morphine intrathécale à 90–150 patients. Une dépression respiratoire nécessitant un traitement par la naloxone a été décrite chez 23 patients traités par la morphine pa voie péridurale (0,25–0,40%) et chez six patients traités par la morphine par voie intrathécale (4–7%). Chez 22 patients, l’administration de morphine par voie péridurale a été considérée comme un facteur principal ou aggravant de survenue d’une dépression respiratoire. Seuls deux patients parmi ces 22 ont objectivé cette dépression respiratoire plus de 6 h après la dernière dose d’opiacé (s.c., i.m., i.v. ou péridurale). Il semble y avoir eu une sur-représentation de patients de 70 ans et plus, de patients ayant subi une analgésie péridurale dorsale et de patients ayant une capacité respiratoire diminuée. GEFÄHRLICHE NEBENWIRKUNGEN VON PÉRIDURALER UND INTRATHEKALER ANWENDUNG VON OPIATEN: BERICHT ÜBER EINE LANDESWEITE RETROSPEKTIVE UNTERSUCHUNG IN SCHWEDEN
ZUSAMMENFASSUNG
Die Schwedische Gesellschaft für Anästhesie führte eine landesweite retrospektive Untersuchung über die klinischen Erfahrungen mit der epiduralen und intrathekalen Verabreichung von Opiaten durch. Das besondere Interesse galt der Häufigkeit und der Art einer dabei auftretenden Atemdepression. Den Fragebogen beantworteten 84 von 93 Abteilungen (90%). Bis zum Mai 1981 hatten 6000 bis 9150 Patienten Morphium epidural, ca. 220 bis 450 Patienten epidural Pethidin und 90 bîs 150
Patienten intrathekal Morphium erhalten. Über das Auftreten einer Atemdepression, die Behandlung mit Naloxon erforderlich machte, wurde bei 23 Patienten, denen epidural Morphium 0,25–0,40% und bei 6 Patienten, denen intrathekal Morphium 4–7% verabreicht worden war, berichtet. Bei 22 Patienten nahm man an, daß die Verabreichung von epiduralem Morphium den hauptsächlichen oder einen zusätzlichen Faktor für das Auftreten einer Atemdepression darstellte. Nur zwei von diesen 22 Patienten hatten später als 6 Stunden nach der letzten Opiatdosis (s.c., i.m., i.v. od epidural) eine Atemdepression. In der Gruppe mit Atemdepression befanden sich vermehrt Patienten, die 70 Jahre oder älter waren, oder bei denen eine Epiduralpunktion in der Thorakalregion durchgeführt worden war oder solche mit eingeschränkter Lungenfunktion.
EFECTOS ADVERSOS DE LOS OPIATOS EXTRADURALES E INTRATECALES: INFORME DE UN ESTUDIO EFECTUADO EN SUECIA A ESCALA NACIONAL
SUMARIO
La Sociedad Sueca de Anestésicos ha llevado a cabo un estudio restrospectivo a nivel nacional al respecto de las experiencias clinicas con los opiatos de administratión extradural e intratecal. Se emplazó un interés especial sobre la frecuencia y el tipo de depresión respiratoria. El cuestionario lo contestaron 84 de los 93 departamentos contactados (90%). Hasta el mes de mayo de 1981 se había administrado morfina extradural a entre 6000 y 9150 pacientes, petidina extradural a entre 220 y 450 pacientes y morfina intratecal a entre 90 y 150 pacientes. Se informó el uso de naloxano como tratamiento de la depresión respiratoria en 23 pacientes tratados con morfina extradural (0,25–0,40%) y en seis a los que se les administró morfina intratecal (4–7%). En 22 de los pacientes la administración de morfina extadural se consideró como un factor principal o contribuyente a la aparición de depresión respiratoria. Tan sólo dos de los 22 pacientes experimentaron depresión respiratoria después 6 horas de haber administrado la última dosis de opiatos (subcutánea, intramuscular, intravenosa o extradural). Parece ser excesiva la representación de pacientes de edad igual o superior a los 70 años, la de aquellos que recibieron inyección toráctica extradural y la de aquellos con capacidad ventiladora reducida.
