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Year : 2010  |  Volume : 4  |  Issue : 2  |  Page : 64-68  

Critical incidents during anesthesia in a developing country: A retrospective audit

Department of Anaesthesia, College of Medicine University of Nigeria, Enugu campus, Nigeria

Date of Web Publication3-Dec-2010

Correspondence Address:
A O Amucheazi
Department of Anaesthesia, College of Medicine University of Nigeria, Enugu campus
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0259-1162.73508

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Background: Critical incidents occur inadvertently where ever humans work. Reporting these incidents and near misses is important in learning and prevention of future mishaps. The aim of our study was to identify the incidence, outcome and potential risk factors leading to critical incidents during anaesthesia in a tertiary care teaching hospital and attempt to suggest preventive strategies that will improve patient care.
Materials and Methods: A retrospective audit of all anaesthesia charts for documented critical incidents over a 12 month period was carried out. Age and ASA classification of patient, urgency of surgery, timing of the incident, body system involved and the grade of the anaesthetists were noted. The data collected was analysed using the SPSS software.
Results: Fourteen incidents were documented in 54 patients, giving a frequency of 0.071. More females suffered critical incidents. Patients in the 4 th and 5 th decades of life were noted to be more susceptible. Airway and cardiovascular incidents were the commonest. Anaesthetists with less than 6 years experience were involved in more mishaps.
Conclusion: We conclude that airway mishaps and cardiovascular instability were the commonest incidents especially in the hands of junior anaesthetists.

Keywords: Anesthesia, critical incidents, documentation, safety

How to cite this article:
Amucheazi A O, Ajuzieogu O V. Critical incidents during anesthesia in a developing country: A retrospective audit. Anesth Essays Res 2010;4:64-8

How to cite this URL:
Amucheazi A O, Ajuzieogu O V. Critical incidents during anesthesia in a developing country: A retrospective audit. Anesth Essays Res [serial online] 2010 [cited 2022 May 16];4:64-8. Available from:

   Introduction Top

Adverse events occur in any area of medicine, more so in anesthesia. This may be due to errors in patient management, deviation from the standards of practice and no help available for proper intervention.

When these incidents occur, the analysis of these is important, but not as a means of apportioning blame. Rather, they serve as a window on the system, a basis for training, simulation, and the improvement in standards of anesthesia care. [1] Also, the sharing and discussion of critical incidents would help to evolve new policies to prevent recurrences. [2]

   Materials and Methods Top

From January 1 to December 31, 2008, the anesthetic records of all patients who had undergone either general or regional anesthesia at the University of Nigeria Teaching Hospital, Ituku-Ozalla, were reviewed on a case by case basis for documented intraoperative critical incidents in this retrospective study. These deaths were further analyzed to identify contributing aspects of anesthetic procedure, operation and patient's comorbidity. The overall mortality rate was determined from the total number of anesthetics and deaths. The perioperative deaths were assigned to one of the three groups: related to anesthesia (anesthesia was the major contributive factor), partially related to anesthesia and most probably unrelated to anesthesia. All documented critical incidents occurring in the time frame were retrospectively and anonymously collected. Age and ASA classification of patient, urgency of surgery, timing of the incident, body system involved and the grade of the anesthetists were noted. Basic safety monitoring in all patients included continuous electrocardiogram display, noninvasive blood pressure, capnography and pulse oximetry. The data collected were subjected to analysis using the SPSS software

   Results Top

During the 1-year study, 1536 patients were administered anesthetic agents. Fourteen incidents were documented in 54 patients, giving a frequency of 0.071. Critical incidents were reported but with complete recovery in 51 (94.4%) and mortality in 3 (5.6%) cases. Distribution of critical incidents was somewhat different in males and females (46.3 and 53.7%, respectively), with a maximum incidence in 30-39 and 40-49 year age group (20%).

Forty-six (85.2%) had elective surgery while eight (14.8%) had emergency procedures [Table 1]. Majority of the critical incidents occurred in ASA grade I and II (60-65%) patients as compared to ASA III and IV patients [Figure 1]. The frequency of critical incidents was maximum in patients with no pre-existing systemic involvement (n=69, 61.61%), followed by cardiovascular (n=19, 16.96%) and respiratory (n=8, 7.14%) involvement. Critical incidents were observed more between 9 a.m. and 6 p.m. (85.2%) in elective patients and in patients admitted for general surgery (43.75%).
Figure 1: American Society of Anesthesiologists (ASA) physical status grade of patients

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Table 1: Timing of surge

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Three mortalities (1 per 512) were registered among the patients of ASA I-III physical status and eight mortalities were registered in the early postoperative period. Ratio of preoperative mortalities among the elective and emergency operations was 3:0. Of the three deaths, two were associated with hypoxic injury due to loss of airway and aspiration in adult and pediatric patients, respectively; the other one was due to intraoperative hemorrhage and the resultant unavailability of banked blood. Incidents occurred more frequently in patients who received general anesthesia (90%). Critical incidents occurred most commonly during the maintenance phase (75%) and least at the stage of extubation (<2%) [Table 2]. Cardiovascular incidents documented were hypotension (63%) and bradycardia (7.4%) [Table 3]. Respiratory incidents were as follows: failed intubation 5.6%, failed intubation with failed ventilation 1.9%, hypoxia 7.4% [Table 4]. Other adverse events included oxygen and power failure which were less than 2%.
Table 2: Stage of occurrence of critical incidents

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Table 3: Cardiovascular incidents

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Table 4: Respiratory incidents

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The monitors attached to patients were ECG, sphygmomanometer, pulse oximetry, and precordial stethoscope in children. The anesthetists involved were mainly senior and junior registrars supervised by consultants. The incidents occurred during maintenance 75.9%, emergence 11.1% and induction 7.4%. ASA I and II patients were manly involved in over 70% of the cases.

Critical incidents occurred in mainly cases (>50%) which were being conducted independently by resident doctors with 1-5 years experience. There was no indication of stress among the anesthetists conducting the cases. The critical incidents occurred at the period when workload of the anesthetists was less than 12 hours over a 24-hour period. There was no report of contributing factors like haste and distraction, but there was lack of help at such times.

   Discussion Top

Whereever humans work, failures inevitably do occur. [3] These errors are often identifiable and repetitive, so they can be analyzed and classified. [4] Accurate analysis of critical incidents requires on the spot assessment and or in depth reporting in order to determine the etiology and develop preventive strategies. In the event of lack of a standard definition and with inaccurate data, there is paucity of assessment.

Regarding the major areas of risks in anesthesia, the most valuable source of information can be derived from the ASA Closed Claims Project Database and the National Confidential Enquiry into Perioperative Deaths (NCEPOD) reports. [5],[6]

Despite arguments by Largesse about the current opinion that anesthesia is measurably safer in these times, very serious events are becoming rarer in the population. [7] The outcome of critical incidents invariably will depend on the degree of insult, timely intervention and the patient's baseline health status. Anesthesia-related mortality in most developed countries is now <1:50,000 anesthetics; in healthy young patients of ASA I-II physical status, it is much lower, i.e., 1 per 250,000. [8],[9] Self-auditing is important to improve the standard of care. [10] The first edition of the Confidential Enquiry into Perioperative Deaths arranged by both the Association of Anaesthetists and the Association of Surgeons of Great Britain and Ireland examined perioperative deaths occurring during 12 months in three National Health Service regions. Death attributable to anesthesia alone was only 0.05 per 10,000 anesthetics. [11],[12],[13],[14],[15],[16],[17]

Three perioperative mortalities were identified during the period among 1536 anesthetics in the teaching hospital, with a suggested overall intraoperative mortality rate of approximately 1/512 anesthetics.

Two of the fatal outcomes occurred intraoperatively due to airway difficulty and aspiration of recently eaten food (the patients' relatives had defaulted on the fasting guidelines and admitted so only when the patient aspirated). However, the other mortality (intraoperative hemorrhage) was probably not attributable directly to anesthetic management, but to surgical skill, lack of blood and inadequate preparation of the patient.

The frequency of incidents reported from different institutions varied from 0.28 to 2.8%, while higher incidences of 12.1 and 10.6% have also been reported. [14],[15],[16],[17],[18],[19] In a Zimbabwean study, Madzimbamuto and Chiware reported a 0.92% of intraoperative critical incidents. [20] The difference in these figures lies in the fact that interpretation of the term "critical incidence" in anesthesia varies according to individual perception of an incident and to an ambiguity in how these are applied in practice. There may be a reluctance to report seemingly minor events. Also, some major events go unreported for fear of retribution and lack of motivation and a formal reporting system.

In a study by Ajaj and Pansalovich, patients with ASA physical status III-V were found to be at significantly higher risk than those with ASA physical status I or II. [21] A study by Dawlatly had Emergency surgery and patient ASA physical status III-IV as significant predictors of critical incident reports. [10] In our audit, incidence of critical incidents and mortalities was maximum in ASA I and II patients probably because maximum number of surgical patients belonged to this physical status. In higher ASA physical status patients, experienced anesthetist attendance, stringent monitoring and extra vigilance could be a reason for less incidence. [22],[23]

Critical incidents related to airway management have been found in 17-34% of incidents and airway management has been shown to contribute to approximately one-quarter of anesthesia related deaths. [16],[24],[25],[26],[27],[28],[29] In our audit, cardiovascular causes were more frequently responsible for anesthesia related critical incidents and morbidity was mainly due to hypotension and bradycardia. This was followed by respiratory incidents which included failed intubation, failed intubation with failed ventilation, laryngospasm, bronchospasm and aspiration.

In many studies, human error has been implicated as the major cause of anesthesia related critical incidents and mortality. [21],[26],[30],[31],[32],[33],[34],[35] Poor judgment or lack of experience, skill as well as failure to check were the most frequently reported factors for human errors. It is known that the basis for all accidents or near accidents in any situation is unsafe practice or working condition. [36] The main factor which determined the rate of critical incidents was the skill and judgment of the anesthetists.

Maaloe et al. and Braz et al. found that there has been a slightly higher incidence of critical incidents and mortalities in emergency surgery as compared to elective surgery. [37],[38] Poor optimization of patient's preoperative status, nonavailability of equipments, emergency drugs, investigation facilities and poor operating conditions are all contributory factors in emergency situation in developing countries.

Furthermore, critical incidents have been found to occur mostly during the daytime. [23] This coincides with the peak of working hours in our hospital. One, however, may argue that anesthetists working at late hours (calls) may be less compliant with incident reporting.

We found in common with other studies that the frequency of critical incidents was higher with general than neuraxial anesthesia. [22],[29] However, this may be because many high risk surgeries are performed under general anesthesia. Likewise, there may be a bias toward general anesthesia in emergency settings or in patients with coexisting medical conditions.

We also found a correlation between occurrence of critical incidents and experience level of anesthesiologist. [23],[33] The operating suite was observed as a vulnerable site for occurrence of critical incidents. [23],[39] Induction and maintenance phase have been considered as "incident rich phase" and we found a higher incidence in the similar phase. [6],[8]

Risk of anesthesia depends on the area involved, with developing countries having a higher risk when compared to developed countries. From this study, patient factors need to be keyed in. It was discovered that only after the patient had aspirated, the patient's parents had been economical with the truth regarding observing the preoperating fasting guidelines that morning. Care must be taken to ensure that patients comply with fasting guidelines because what is regarded as food differs from patient to patient. Some regard tea and soft drinks as no food, with "fufu" (local parlance for cassava) and rice considered as food. Some other patients believe that a child must eat in order to have "energy" for the surgical procedure. In developing countries, anesthetists have to deal with poorly treated comorbid conditions. Emergency surgical patients often present late with poor optimization from the referral hospital.

Furthermore, there are deficiencies in hospital facilities, shortages in anesthetic staff, failure to properly use the different strata of health care (primary, secondary and tertiary facilities which may also be ill-equipped and manned), inadequate or no supervision of junior medical staff and patronage of alternative health care givers. Poverty also adds to the illness burden with some patients not able to purchase drugs, run necessary tests, thus causing the anesthetist to look for alternatives and cut corners in a bid to save life. Modern equipment as well as appropriately trained personnel and adequate guidelines for practice should be procured in hospitals.

There is some degree of methodological weakness in our study. There could be underreporting since this was a retrospective study, the basis of which was voluntary reporting of adverse events attending anesthetists. Opinions may vary on what is termed adverse events and fear of punitive measures may undermine incident reporting. Secondly, this study spanned a period of 1 year. This obviously represents an unknown proportion of all mishaps that occur in association with anesthesia. The small sample size may be too small to accurately calculate statistical significance of risk factors.

When critical incidents occur, they must be investigated not with the goal of apportioning blame but as a means of finding the chain of events and contributory factors that led to it, in order to prevent further occurrences. Such an investigation will reveal gaps and inadequacies in the health care system. Furthermore, because it is a proactive activity (not a mortality review), it is more attractive, forward looking and should be encouraged.

In conclusion, anesthesia continues to be associated with morbidity and mortality despite the advancements made in equipment monitors and drugs. In view of the fact that human error is the single most important factor in the majority of these incidents, we strongly suggest that strategies and protocols should be developed relative to local content and practice in order to increase and update the knowledge base and thus avoid errors of judgment. Evidence points to the fact that the use of checklists, protocols and improved awareness of the relevance of critical incidents can improve the safety of anesthetic practice. [18] Thus, critical incident reporting should be introduced in all anesthesia departments as part of quality assurance programs to ensure improved patient care, as an educational tool but never as a punitive measure. [40]

   References Top

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  [Table 1], [Table 2], [Table 3], [Table 4]

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