Anaesthesia, 1990, Volume 45, pages 3-6
Accidents, near accidents and complications during anaesthesia A retrospective analysis of a 10-year period in a teaching hospital
V. CHOPRA, J. G. BOVILL
AND
J. SPIERDIJK
?
Summary A retrospective analysis is presented of all reports of faults, accidents, near accidents and complications associated with anaesthesia in one hospital from 1978 to 1987. 113 074 anaesthetics were administered in that period, of which 97496 were for noncardiac procedures. There were 148 reports; 39 were of dental damage. Peri-operative cardiac arrests during noncardiac surgery were reported 29 times. Sixteen of these were fatal. Anaesthesia was thought to havc played an important role in 13 cardiac arrests ( I per 7500 anaesthetics) and six were not successfully resuscitated ( I per 16 250 anaesthetics). There were 12 reports of postoperative peripheral neuropathies (1 per 9422 anaesthetics). Failure to check, lack of vigilance and inattention or carelessness were the most frequently associated factors with the rest of the reports.
Key words Complications; accidents, cardiac arrest. Statistics; mortality rates.
The risk of death attributable to anaesthesia has decreased from 1 in 2680’ to 1 in 1000Ozin the period from 1954 to 1982. Z e i t h ~reported ,~ a possible 13-fold decrease in death rate related to general anaesthesia in the period 1977-84 as compared to the period 1955-64. However, in the recent report of a confidential enquiry into peri-operative deaths: only 3 deaths in 555 258 anaesthetics were solely because of anaesthesia (an incidence of 1 death in 185056 anaesthetics). Anaesthesia, while associated with low mortality in recent years, is still associated with a significant m ~ r b i d i t y . ~ Human error is an important factor in the causation of anaesthesia-related faults, near accidents and accidenk6J The methods used to gather information about the safety of anaesthesia and to establish the risk of mortality, morbidity and complications have included anecdotal tales, in-hospital audit and peer reviews, reports to medical defence societies, retrospective studies, reviews of specific problems and prospective studies. We present here a retrospective analysis of reports of anaesthesia-related accidents, near accidents, faults and complications during a 10-year period in one hospital. Methods and results
In 1976, a Faults, Accidents and Near Accidents (FONA) Committee was established in the University Hospital Leiden. The task of this Committee is to collect and analyse reported faults, accidents, near accidents and complications
that relate to patient care in the hospital. Medical and nursing staff are required to report all occurrences to the Committee. Patients also have the right to report directly to the FONA Committee. These definitions are used by the Committee. Fault. A procedure, which has resulted (or could have resulted) in injury or harm to a patient, while this injury or harm (or chance thereof) could have been prevented by another procedure. Accident. Any event, except a fault or a complication, which has resulted in harm or injury to a patient. Near accident. An event, which could have developed into a fault, a cclnplication or an accident, but which was prevented from so developing either by chance or by a previously unplanned intervention. Complication. Harm or injury to a patient occurring as a result of a known risk of a treatment or a diagnostic procedure. We have analysed all the records of reports made to the FONA Committee by the Department of Anaesthesiology, during the 10-year period from 1978 to 1987. In that period 113 074 anaesthetics were administered, of which 97 496 were for noncardiac surgery. There were 148 reports to the FONA Committee. A breakdown of these reports according to categories is shown in Table 1. The largest single group is that of dental damage, followed by perioperative cardiac arrests. The total incidence of cardiac arrests associated with noncardiac surgery was 1 in 3362.
V. Chopra, MB, BS, FFARCS, Staff Anaesthetist, J.G. Bovill, MD, PhD, FFARCSI, Research Professor, J. Spierdijk, MD, PhD, FFARCS(Hon), Professor, Department of Anaesthesiology, University Hospital Leiden, Post Box 9600, 2300 RC Leiden, The Netherlands. Accepted 3 August 1989. 0003-2409/90/010003 + 04 %03.00/0
@ 1990 The Association of Anaesthetists of G t Britain and Ireland
3
4
V. Chopra, J.G. BoviN and J. Spierdijk
Table 1. An analysis of reports to the Faults, Accidents and Near Accidents (FONA) Committee.
Category
Number
"r
5
5
39 18 11 8 6 2
Dental damage Cardiac arrests (with fatal outcome) Cardiac arrests (successfully resuscitated) Wrong drug administration Wrong dose Wrong blood administration Skin burns Peripheral neuropathies Hypotension and bradycardia Miscellaneous Total
5 12 7 40
V
I
0-10
148
I IL20 21-30 31-140 41-50 51160 61170 71-80 Age in years
Fig. 2. Fatal cardiac arrests in relation to the age groups.
?
Eighteen of the 29 (62%) cardiac arrests had a fatal outcome, giving an incidence of 1 death per 5417 anaesthetics for noncardiac surgery. Anaesthesia was thought to have played a role in the causation of cardiac arrests in 13 patients (1 in 7400). Six of these 13 patients could not be successfully resuscitated (1 in 16 250). The majority of deaths associated with anaesthesia (61 YO)involved patients with an ASA classification 4 and 5 (Fig. 1). Ten of the 18 deaths (55%) were in patients older than 60 years of age (Fig. 2). None of the patients with an ASA classification 4 and 5 , who developed cardiac arrests could be successfully resuscitated (Fig. 3). Details of patients within an ASA classification 1-3 who developed cardiac arrests in the peri-operative period, are summarised in Table 2. There was thought to be a preventable cause for the cardiac arrest in 8 of these 17 patients. Errors in drug administration and hypoxia were the most commonly associated preventable factors. There were 14 reports of faults in drug administration (Table 3) and two reports of administration of wrong blood. Twenty-one of 39 reports of dental damage involved either patients with carious teeth or those who presented with a difficult intubation. Of the rest, one was an emergency intubation, one a patient with faciomaxillary fracture and in 16, no clear cause was identifiable. These 16 reports were made by patients directly to the Committee. No record of dental damage was made on the anaesthetic charts. All of the five reports of skin burns except one were
ASA 3
caused by a faulty diathermy plate. One incident was caused by the use of 'cold' light source of a bi-onchoscope for transillumination of the radial artery during arterial cannulation in a child. There were 12 reports of peripheral nerve injuries, an incidence of 1 per 9422 anaesthetics. Seven of these involved the ulnar nerve; two the brachial plexus; one each, the radial and the median nerves; and one was cauda equina syndrome that occurred after a spinal block. Eight of these 12 nerve injuries were caused by an incorrect position of the patient during anaesthesia. Forty other reports were grouped together as miscellaneous. Fourteen of these were classified as complications while the rest were faults, accidents or near accidents. The factors associated with these are summarised in Table 4.
Discussion This study, like all retrospective studies, suffers from limitations. The reports on which our findings are based are not necessarily a fully accurate representation of what occurred. There may have been failure to record significant events at the time of their occurrence. The possibility of bias within the reports cannot be excluded since these were not made anonymously. It is probable in this study that most serious mishaps were reported, but not all minor incidents. It is also possible that some deaths were not reported because they were thought to be as a result of the
ASA 2 I7 %
ASA 5 44 %
Fig. 1. Fatal cardiac arrests in relation to the physical status of patients.
-
ASA I
ASA2
ASA3
Ash4
Ash5
Fig. 3. Peri-operative cardiac arrests in relation to the physical status of patients. Hatched areas represent successful resuscitations.
5
Accidents during anaesthesia Table 2. Summary of cardiac arrests in patients with an ASA classification 1-3. Age (years)
Fatal ASA status outcome
2 4 26*
3
34
I
No No No No
38 4x
I 3
No Yes
54*
2
No No No No
54* Sl* 5X*
I
-7
-7 2 3
59 68 68*
2
3
Yes Yes No
72 72*
I 3 .
Yes Yes
73* 76
3 2
Yes Yes
7
&
?
Description Cardiorespiratory arrest after caudal block. Intravenous injection of bupivacaine. Hyperkalaemia after intravenous suxamethonium in a child with rhabdomyosarcoma Overdose of halothane due to unintentionally open vaporizer. Anaphylactic shock due to hypersensitivity to intra-uterine dextran during hysteroscopy under general anaesthesia. Surgical bleeding and hypotension during pneumonectomy. Hypoxia as a result of difficult tracheal intubation because of anatomical malformation. Later tracheostomy (pre-induction tracheostomy was indicated). Overdose of neurolept anaesthesia leading to postoperative respiratory arrest in the recovery room, Hypotension leading to cardiac arrest during epidural anaesthesia. Hypoxia due to accidental bronchial intubation. Hyperkalaemia because of rapid intravenous injection of potassium chloride during general anaesthesia. I n the recovery room, after adbominal surgery. Autopsy revealed myocardial infarction. High epidural or total spinal block. Hypoventilation in spontaneously breathing patient, and hypokalaemia treated with rapid intravenous administration of potassium chloride during general anaesthesia, leading to ventricular fibrillation. Cardiorespiratory arrest, possibly related to intravenous regional block with bupivacaine. Cardiac arrest during epidural general anaesthesia. History of pre-operative myocardial infarction. Possible cause intra-operative hypotension and myocardial infarction. Ventilator disconnexion with alarms switched off in the postoperative period. Myocardial infarction during general anaesthesia. Large dose of lignocaine given during resuscitation because wrong concentration of solution was used.
+
*Possibly preventable cases.
disease concerned or surgical factors. We consider that these records in spite of these limitations d o represent a rcasonable picture of anaesthesia-associated complications, near accidents, accidents and faults in our hospital. Dental damage could be considered a relatively minor accident in terms of patient morbidity but it was the most commonly reported accident. One of the reasons for such frequent reports may have been the anaesthetist's fear of possible litigation or medicolegal problems associated with dental damage. The majority of these occurred in patients with carious teeth or in those who presented as a difficult tracheal intubation. The reports of cardiac arrests and deaths probably reflect their true incidence. A cardiac arrest o r a death which occurs solely or principally as a result of anaesthetic misad-
Table 3. Faults in drug administration. 100"/0 nitrous oxide instead of 100% oxygen at the end of
anaesthesia. Intramusclular suxamethonium instead of ketamine to a child. Isoprenaline instead of atropine during an episode of bradycardia. Intravenous sodium citrate instead of potassium chloride. Intravenous sufentanil instead of alfentanil during general anaesthesia. Intravenous administration of saline solution which was not intended for intravenous use. Adrenaline given instead of atropine. Wrong premedication given. Overdose of fentanyl during neurolept anaesthesia. Wrong concentration of lignocaine during cardiorespiratory resuscitation. Wrong dose of antibiotics to a child. Interchange of inlet and outlet of halothane (Fluotec) vaporizer leading to overdose. Rapid intravenous injection of potassium chloride during general anaesthesia. Ketamine overdose as a result of calculation based o n wrong weight of a child.
venture was very rare. Most of the deaths involved either elderly patients or patients in poor physical condition. Similar conclusions were drawn in the report of the Confidential Enquiry into Peri-Operative Deaths (CEPOD).4 The incidence of anaesthesia-related cardiac arrest was I .3 per 10 000 anaesthetics in our study. This is comparable to the incidence of 1.7 per 10 000 anaesthetics reported by Keenan and Boyan.x The incidence of fatal cardiac arrests as a result of anaesthesia misadventure in our study was 0.6 per 10 000 anaesthetics as compared to 0.9 per 10 000 anaesthetics reported by Keenan and Boyan.x Fourteen incidents which involved drug administration (wrong drug o r wrong dose) were reported but it is probable that the real incidence of such occurrences was much higher. These 14 reported incidents were serious enough to cause anaesthetists to make voluntary reports. Lack of vigilance and carelessness on the part of the anaesthetist were common factors in all these incidents. The incidence of peripheral neuropathies in this study was 10 times lower than that reported in previous Dhuner, in 1950, reported an incidence of 1 per 1000 anaesthetics.' Twenty years later, Parks reported one peripheral neuropathy per 700 anaesthetics.ln Both of these studies involved a retrospective review of the records of all
Table 4. Summary of associated factors with reports of the miscellaneous group. Associated factors Complications Failure to check Inattention or carelessnes Lack of communication Improper technique Lack of adequate experience Poor maintenance of the operating theatre Total
Numbers 14
9 6 5 4
1 1 40
6
V . Chopra, J.G. Bovill and J. Spierdijk
patients who were anaesthetised during the study period. We have reviewed only the reported injuries. It is possible that not all the nerve injuries were reported. Inappropriate body position during anaesthesia was the most commonly involved factor in causation. It is highly probable that the reports to the FONA committee presented in this paper represent only a proportion of all faults, accidents, near accidents and complications that occur in association with anaesthesia. Nonetheless, we consider that some careful conclusions can be drawn. Anaesthesia continues to be associated with morbidity and mortality despite improvements in drugs and equipment. Human error is the most important factor in the majority of these incidents. It is known that the basis of all accidents or near accidents in any situation is unsafe practices or working conditions." Therefore, in order to assess the risk of anaesthesia, carefully planned and executed prospective studies are needed to study those unsafe practices or conditions which might result in an accident, a fault br a near accident. References 1. BEECHER HK, TODDDP. A study of the deaths associated with anaesthesia and surgery based on a study of 599,548
anaesthesias in 10 institutions 1948-52 inclusive. Annals of Surgery 1954; 140 2-35. 2. LUNNJN, MUSHINWW. Mortality associated with anaesthesia. London: The Nuffield Provincial Hospitals Trust, 1982. 3. ZEITLINGL. Possible decrease in mortality associated with anaesthesia: a comparison of two time periods in Massachusetts, USA. Anaesthesia 1989; 44: 432433. 4. BUCKN, DEVLINHB, LUNNJN. The report of a confidential enquiry into perioperative deaths. London: The Nuffield Provincial Hospitals Trust and The King's Fund, 1987. 5. COHENMM, DUNCAN PG, POPEWDB, WOLKENSTEIN C. A survey of 112,000 anaesthetics at one teaching hospital (197583). Canadian Anaesthetists' Society Journal 1986; 33: 22-31. 6. CRAIGJ, WILSONME. A survey of anaesthetic misadventure. Anaesthesia 1981; 36: 933-6. 7. COOPERJB, NEWBOWER RS, KITZ RJ. An analysis of major errors and equipment failures in anesthesia management: consideration for prevention and detection. Anesthesiology 1984; 60: 3 U 2 . 8. KEENAN RL, BOYANP. Cardiac arrests due t a anesthesia. A study of incidence and causes. Journal of the American Medical Association 1985; 2 5 3 2373-77. 9. DHUNERKG. Nerve injuries following operations: a survey of cases occurring during a six year period. Anesthesiology 1950; 11: 289-93. 10. PARKSBJ. Postoperative peripheral neuropathies. Surgery 1973; 74: 348-57. 11. HEINRICHHW, PETERSON D, Roos N. Industrial accident prevention: a safety management approach, 5th edn. New York: McGraw Hill, 1980: 60.
Accidents, near accidents and complications during anaesthesia A retrospective analysis of a 10-year period in a teaching hospital
V. CHOPRA, J. G. BOVILL
AND
J. SPIERDIJK
?
Summary A retrospective analysis is presented of all reports of faults, accidents, near accidents and complications associated with anaesthesia in one hospital from 1978 to 1987. 113 074 anaesthetics were administered in that period, of which 97496 were for noncardiac procedures. There were 148 reports; 39 were of dental damage. Peri-operative cardiac arrests during noncardiac surgery were reported 29 times. Sixteen of these were fatal. Anaesthesia was thought to havc played an important role in 13 cardiac arrests ( I per 7500 anaesthetics) and six were not successfully resuscitated ( I per 16 250 anaesthetics). There were 12 reports of postoperative peripheral neuropathies (1 per 9422 anaesthetics). Failure to check, lack of vigilance and inattention or carelessness were the most frequently associated factors with the rest of the reports.
Key words Complications; accidents, cardiac arrest. Statistics; mortality rates.
The risk of death attributable to anaesthesia has decreased from 1 in 2680’ to 1 in 1000Ozin the period from 1954 to 1982. Z e i t h ~reported ,~ a possible 13-fold decrease in death rate related to general anaesthesia in the period 1977-84 as compared to the period 1955-64. However, in the recent report of a confidential enquiry into peri-operative deaths: only 3 deaths in 555 258 anaesthetics were solely because of anaesthesia (an incidence of 1 death in 185056 anaesthetics). Anaesthesia, while associated with low mortality in recent years, is still associated with a significant m ~ r b i d i t y . ~ Human error is an important factor in the causation of anaesthesia-related faults, near accidents and accidenk6J The methods used to gather information about the safety of anaesthesia and to establish the risk of mortality, morbidity and complications have included anecdotal tales, in-hospital audit and peer reviews, reports to medical defence societies, retrospective studies, reviews of specific problems and prospective studies. We present here a retrospective analysis of reports of anaesthesia-related accidents, near accidents, faults and complications during a 10-year period in one hospital. Methods and results
In 1976, a Faults, Accidents and Near Accidents (FONA) Committee was established in the University Hospital Leiden. The task of this Committee is to collect and analyse reported faults, accidents, near accidents and complications
that relate to patient care in the hospital. Medical and nursing staff are required to report all occurrences to the Committee. Patients also have the right to report directly to the FONA Committee. These definitions are used by the Committee. Fault. A procedure, which has resulted (or could have resulted) in injury or harm to a patient, while this injury or harm (or chance thereof) could have been prevented by another procedure. Accident. Any event, except a fault or a complication, which has resulted in harm or injury to a patient. Near accident. An event, which could have developed into a fault, a cclnplication or an accident, but which was prevented from so developing either by chance or by a previously unplanned intervention. Complication. Harm or injury to a patient occurring as a result of a known risk of a treatment or a diagnostic procedure. We have analysed all the records of reports made to the FONA Committee by the Department of Anaesthesiology, during the 10-year period from 1978 to 1987. In that period 113 074 anaesthetics were administered, of which 97 496 were for noncardiac surgery. There were 148 reports to the FONA Committee. A breakdown of these reports according to categories is shown in Table 1. The largest single group is that of dental damage, followed by perioperative cardiac arrests. The total incidence of cardiac arrests associated with noncardiac surgery was 1 in 3362.
V. Chopra, MB, BS, FFARCS, Staff Anaesthetist, J.G. Bovill, MD, PhD, FFARCSI, Research Professor, J. Spierdijk, MD, PhD, FFARCS(Hon), Professor, Department of Anaesthesiology, University Hospital Leiden, Post Box 9600, 2300 RC Leiden, The Netherlands. Accepted 3 August 1989. 0003-2409/90/010003 + 04 %03.00/0
@ 1990 The Association of Anaesthetists of G t Britain and Ireland
3
4
V. Chopra, J.G. BoviN and J. Spierdijk
Table 1. An analysis of reports to the Faults, Accidents and Near Accidents (FONA) Committee.
Category
Number
"r
5
5
39 18 11 8 6 2
Dental damage Cardiac arrests (with fatal outcome) Cardiac arrests (successfully resuscitated) Wrong drug administration Wrong dose Wrong blood administration Skin burns Peripheral neuropathies Hypotension and bradycardia Miscellaneous Total
5 12 7 40
V
I
0-10
148
I IL20 21-30 31-140 41-50 51160 61170 71-80 Age in years
Fig. 2. Fatal cardiac arrests in relation to the age groups.
?
Eighteen of the 29 (62%) cardiac arrests had a fatal outcome, giving an incidence of 1 death per 5417 anaesthetics for noncardiac surgery. Anaesthesia was thought to have played a role in the causation of cardiac arrests in 13 patients (1 in 7400). Six of these 13 patients could not be successfully resuscitated (1 in 16 250). The majority of deaths associated with anaesthesia (61 YO)involved patients with an ASA classification 4 and 5 (Fig. 1). Ten of the 18 deaths (55%) were in patients older than 60 years of age (Fig. 2). None of the patients with an ASA classification 4 and 5 , who developed cardiac arrests could be successfully resuscitated (Fig. 3). Details of patients within an ASA classification 1-3 who developed cardiac arrests in the peri-operative period, are summarised in Table 2. There was thought to be a preventable cause for the cardiac arrest in 8 of these 17 patients. Errors in drug administration and hypoxia were the most commonly associated preventable factors. There were 14 reports of faults in drug administration (Table 3) and two reports of administration of wrong blood. Twenty-one of 39 reports of dental damage involved either patients with carious teeth or those who presented with a difficult intubation. Of the rest, one was an emergency intubation, one a patient with faciomaxillary fracture and in 16, no clear cause was identifiable. These 16 reports were made by patients directly to the Committee. No record of dental damage was made on the anaesthetic charts. All of the five reports of skin burns except one were
ASA 3
caused by a faulty diathermy plate. One incident was caused by the use of 'cold' light source of a bi-onchoscope for transillumination of the radial artery during arterial cannulation in a child. There were 12 reports of peripheral nerve injuries, an incidence of 1 per 9422 anaesthetics. Seven of these involved the ulnar nerve; two the brachial plexus; one each, the radial and the median nerves; and one was cauda equina syndrome that occurred after a spinal block. Eight of these 12 nerve injuries were caused by an incorrect position of the patient during anaesthesia. Forty other reports were grouped together as miscellaneous. Fourteen of these were classified as complications while the rest were faults, accidents or near accidents. The factors associated with these are summarised in Table 4.
Discussion This study, like all retrospective studies, suffers from limitations. The reports on which our findings are based are not necessarily a fully accurate representation of what occurred. There may have been failure to record significant events at the time of their occurrence. The possibility of bias within the reports cannot be excluded since these were not made anonymously. It is probable in this study that most serious mishaps were reported, but not all minor incidents. It is also possible that some deaths were not reported because they were thought to be as a result of the
ASA 2 I7 %
ASA 5 44 %
Fig. 1. Fatal cardiac arrests in relation to the physical status of patients.
-
ASA I
ASA2
ASA3
Ash4
Ash5
Fig. 3. Peri-operative cardiac arrests in relation to the physical status of patients. Hatched areas represent successful resuscitations.
5
Accidents during anaesthesia Table 2. Summary of cardiac arrests in patients with an ASA classification 1-3. Age (years)
Fatal ASA status outcome
2 4 26*
3
34
I
No No No No
38 4x
I 3
No Yes
54*
2
No No No No
54* Sl* 5X*
I
-7
-7 2 3
59 68 68*
2
3
Yes Yes No
72 72*
I 3 .
Yes Yes
73* 76
3 2
Yes Yes
7
&
?
Description Cardiorespiratory arrest after caudal block. Intravenous injection of bupivacaine. Hyperkalaemia after intravenous suxamethonium in a child with rhabdomyosarcoma Overdose of halothane due to unintentionally open vaporizer. Anaphylactic shock due to hypersensitivity to intra-uterine dextran during hysteroscopy under general anaesthesia. Surgical bleeding and hypotension during pneumonectomy. Hypoxia as a result of difficult tracheal intubation because of anatomical malformation. Later tracheostomy (pre-induction tracheostomy was indicated). Overdose of neurolept anaesthesia leading to postoperative respiratory arrest in the recovery room, Hypotension leading to cardiac arrest during epidural anaesthesia. Hypoxia due to accidental bronchial intubation. Hyperkalaemia because of rapid intravenous injection of potassium chloride during general anaesthesia. I n the recovery room, after adbominal surgery. Autopsy revealed myocardial infarction. High epidural or total spinal block. Hypoventilation in spontaneously breathing patient, and hypokalaemia treated with rapid intravenous administration of potassium chloride during general anaesthesia, leading to ventricular fibrillation. Cardiorespiratory arrest, possibly related to intravenous regional block with bupivacaine. Cardiac arrest during epidural general anaesthesia. History of pre-operative myocardial infarction. Possible cause intra-operative hypotension and myocardial infarction. Ventilator disconnexion with alarms switched off in the postoperative period. Myocardial infarction during general anaesthesia. Large dose of lignocaine given during resuscitation because wrong concentration of solution was used.
+
*Possibly preventable cases.
disease concerned or surgical factors. We consider that these records in spite of these limitations d o represent a rcasonable picture of anaesthesia-associated complications, near accidents, accidents and faults in our hospital. Dental damage could be considered a relatively minor accident in terms of patient morbidity but it was the most commonly reported accident. One of the reasons for such frequent reports may have been the anaesthetist's fear of possible litigation or medicolegal problems associated with dental damage. The majority of these occurred in patients with carious teeth or in those who presented as a difficult tracheal intubation. The reports of cardiac arrests and deaths probably reflect their true incidence. A cardiac arrest o r a death which occurs solely or principally as a result of anaesthetic misad-
Table 3. Faults in drug administration. 100"/0 nitrous oxide instead of 100% oxygen at the end of
anaesthesia. Intramusclular suxamethonium instead of ketamine to a child. Isoprenaline instead of atropine during an episode of bradycardia. Intravenous sodium citrate instead of potassium chloride. Intravenous sufentanil instead of alfentanil during general anaesthesia. Intravenous administration of saline solution which was not intended for intravenous use. Adrenaline given instead of atropine. Wrong premedication given. Overdose of fentanyl during neurolept anaesthesia. Wrong concentration of lignocaine during cardiorespiratory resuscitation. Wrong dose of antibiotics to a child. Interchange of inlet and outlet of halothane (Fluotec) vaporizer leading to overdose. Rapid intravenous injection of potassium chloride during general anaesthesia. Ketamine overdose as a result of calculation based o n wrong weight of a child.
venture was very rare. Most of the deaths involved either elderly patients or patients in poor physical condition. Similar conclusions were drawn in the report of the Confidential Enquiry into Peri-Operative Deaths (CEPOD).4 The incidence of anaesthesia-related cardiac arrest was I .3 per 10 000 anaesthetics in our study. This is comparable to the incidence of 1.7 per 10 000 anaesthetics reported by Keenan and Boyan.x The incidence of fatal cardiac arrests as a result of anaesthesia misadventure in our study was 0.6 per 10 000 anaesthetics as compared to 0.9 per 10 000 anaesthetics reported by Keenan and Boyan.x Fourteen incidents which involved drug administration (wrong drug o r wrong dose) were reported but it is probable that the real incidence of such occurrences was much higher. These 14 reported incidents were serious enough to cause anaesthetists to make voluntary reports. Lack of vigilance and carelessness on the part of the anaesthetist were common factors in all these incidents. The incidence of peripheral neuropathies in this study was 10 times lower than that reported in previous Dhuner, in 1950, reported an incidence of 1 per 1000 anaesthetics.' Twenty years later, Parks reported one peripheral neuropathy per 700 anaesthetics.ln Both of these studies involved a retrospective review of the records of all
Table 4. Summary of associated factors with reports of the miscellaneous group. Associated factors Complications Failure to check Inattention or carelessnes Lack of communication Improper technique Lack of adequate experience Poor maintenance of the operating theatre Total
Numbers 14
9 6 5 4
1 1 40
6
V . Chopra, J.G. Bovill and J. Spierdijk
patients who were anaesthetised during the study period. We have reviewed only the reported injuries. It is possible that not all the nerve injuries were reported. Inappropriate body position during anaesthesia was the most commonly involved factor in causation. It is highly probable that the reports to the FONA committee presented in this paper represent only a proportion of all faults, accidents, near accidents and complications that occur in association with anaesthesia. Nonetheless, we consider that some careful conclusions can be drawn. Anaesthesia continues to be associated with morbidity and mortality despite improvements in drugs and equipment. Human error is the most important factor in the majority of these incidents. It is known that the basis of all accidents or near accidents in any situation is unsafe practices or working conditions." Therefore, in order to assess the risk of anaesthesia, carefully planned and executed prospective studies are needed to study those unsafe practices or conditions which might result in an accident, a fault br a near accident. References 1. BEECHER HK, TODDDP. A study of the deaths associated with anaesthesia and surgery based on a study of 599,548
anaesthesias in 10 institutions 1948-52 inclusive. Annals of Surgery 1954; 140 2-35. 2. LUNNJN, MUSHINWW. Mortality associated with anaesthesia. London: The Nuffield Provincial Hospitals Trust, 1982. 3. ZEITLINGL. Possible decrease in mortality associated with anaesthesia: a comparison of two time periods in Massachusetts, USA. Anaesthesia 1989; 44: 432433. 4. BUCKN, DEVLINHB, LUNNJN. The report of a confidential enquiry into perioperative deaths. London: The Nuffield Provincial Hospitals Trust and The King's Fund, 1987. 5. COHENMM, DUNCAN PG, POPEWDB, WOLKENSTEIN C. A survey of 112,000 anaesthetics at one teaching hospital (197583). Canadian Anaesthetists' Society Journal 1986; 33: 22-31. 6. CRAIGJ, WILSONME. A survey of anaesthetic misadventure. Anaesthesia 1981; 36: 933-6. 7. COOPERJB, NEWBOWER RS, KITZ RJ. An analysis of major errors and equipment failures in anesthesia management: consideration for prevention and detection. Anesthesiology 1984; 60: 3 U 2 . 8. KEENAN RL, BOYANP. Cardiac arrests due t a anesthesia. A study of incidence and causes. Journal of the American Medical Association 1985; 2 5 3 2373-77. 9. DHUNERKG. Nerve injuries following operations: a survey of cases occurring during a six year period. Anesthesiology 1950; 11: 289-93. 10. PARKSBJ. Postoperative peripheral neuropathies. Surgery 1973; 74: 348-57. 11. HEINRICHHW, PETERSON D, Roos N. Industrial accident prevention: a safety management approach, 5th edn. New York: McGraw Hill, 1980: 60.
