Anaesthesia Related Mortality 2003-2005

Quality Subcommittee

Co-ordinating Committee in Anaesthesiology

Hospital Authority

1 8 May 2007 Anaesthesia Related Mortality 2003-2005

Introduction:

• A territory wide audit in anaesthesia has not been conducted

• Quality Assurance (QA) Subcommittee of the Co-ordinating Committee in Anaesthesiology of the Authority, conducted a HA wide audit on anaesthesia related mortality

• Incidence of anaesthesia related mortality between the years 2003 and 2005

• Analysed the factors leading to death associated with

2 8 May 2007 Anaesthesia Related Mortality 2003-2005

Methodology (1):

• The primary endpoint of this audit, death within 30 days after , was detected by comparing this list of patients with the Hong Kong Government Births and Death Registry

• Since we used the criterion of death within 30 days after surgery, the search was extended to include deaths occurred before 30th January 2006

• The HA Health Informatics Section, together with the assistance of in-house statisticians also facilitated the search process

3 8 May 2007 Anaesthesia Related Mortality 2003-2005

Methodology (2):

• The list of patients who received anaesthesia in one of the 20 HA between 1st January, 2003 and 31st December, 2005, was initially identified by the Clinical Data Analysis and Reporting System (CDARS)

• The CDARS is a powerful tool developed by HA in 2002, it can be considered as a mega data warehouse with inputs from a number of source systems

4 8 May 2007 Anaesthesia Related Mortality 2003-2005 Table 1. Hospitals (n = 20) participating in the anaesthesia related mortality audit

Hong Kong East Cluster Pamela Youde Nethersole Eastern Hospital* Tung Wah East Hospital Our Lady of Maryknoll Hospital Princess Margaret Hospital* Queen Mary Hospital*

The Duchess of Kent Children’s Hospital New Territories East Cluster Alice Ho Mui Ling Nethersole Hospital * North District Hospital Queen Elizabeth Hospital

Kowloon East Cluster New Territories West Cluster United Christian Hospital* *

5 8 May 2007 Anaesthesia Related Mortality 2003-2005 Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong

Source Name of system Information retrieved CMS Clinical Management System Diagonsis, Treatment, Specialist I/C, Medical Officer I/C, Operation Record Reporting System

IPAS Inpatient Admission System Patient demographics, episode movements

OPAS Outpatient Admission System Appointment & attendances information

A&E Accident & Emergency Accident & Emergency attendances

AEIS Attendance Episode Information Attendance information System

PHS / CDDH Pharmaceutical Supply System / Drug dispensed Central Drug Dispensing History

OBCIS Obstetrics Clinical Information Obstetric information System

LIS Laboratory Information System Laboratory test with standardized units

RIS Information System Radiology examination

6 8 May 2007 Anaesthesia Related Mortality 2003-2005 Mortality within 30 days of operation* Hospital 2003 2004 2005 Total A 28 15 27 70 B 94 77 92 263 C 0 0 1 1 D 41 39 28 108 E 5 8 4 17 F 140 140 112 392 G 136 130 150 416 H 0 1 6 7 I 120 174 169 463 J 157 204 195 556 K 168 169 166 503 L 419 379 386 1,187 M 256 241 231 728 N 65 59 42 166 O 42 42 57 141 P 227 217 259 703 Q 13 6 13 32 R 136 176 207 519 S 94 94 76 264

T 0 0 0 0 7 8 May 2007 Overall 2,141 2,171 2,221 6,533 Anaesthesia Related Mortality 2003-2005

Methodology (3):

• All deaths were reviewed by a panel of specialist anaesthesiologists using the electronic patient record (e-PR) system and paper record of patients’ files, if deemed necessary

• The causes of death were classified into 10 categories

• The definition and classification were adopted from the Australian National Health and Medical Council, and the National Anaesthesia Mortality Committee

• This classification was first described by Edwards and co-workers in 1956

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Methodology (4):

• Cases were coded by a co-ordinator

• Reviewed by the adjudication committee

• Two members of the adjudication committee independently assessed the appropriateness of the classification

• Disagreements were resolved by a third member

• Cases that required reclassification were submitted to the adjudication committee again until a consensus was achieved

• The final classification was further reviewed and endorsed by all members of the QA Subcommittee. 9 8 May 2007 Anaesthesia Related Mortality 2003-2005 Mortality Classification CASE CLASSIFICATION A. Deaths attributable to anaesthesia Category 1 Where it is reasonably certain that death was caused by the anaesthesia or other factors under the control of the anaesthesiologist. Category 2 Where there is some doubt whether death was entirely attributable to the anaesthesia or other factors under the control of the anaesthesiologist Category 3 Where death was caused by both surgical and anaesthesia factors. B. Death in which anaesthesia played no part Category 4 Surgical death where the administration of the anaesthesia is not contributory and surgical or other factors are implicated. Category 5 Inevitable death which would have occurred irrespective of anaesthesia or surgical procedures. Category 6 Incidental death which could not reasonably be expected to have been foreseen by those looking after the patient, was not related to the indication for surgery and was not due to factors under the control of anaesthesiologist or surgeon. C. Unassessable death Category 7 Those that cannot be assessed despite considerable data but where the information is conflicting or key data is missing. Category 8 Cases which cannot be assessed because of inadequate data. Category 9 A critical incident where a problem is identified but no mortality occurs. Category 10 Mortality in which anaesthesia and surgical techniques were apparently satisfactory. 10 8 May 2007 Anaesthesia Related Mortality 2003-2005 Table 4. Number of mortalities classified in each category

Category Number of cases 1 10 (43.5%) 2 6 3 7 4 156 5 3,709 6 1,072 7 9 8 323 9 5 10 304 Organ harvesting 25 Duplicate files 907 Total 6,533 (5,601) 11 8 May 2007 Anaesthesia Related Mortality 2003-2005

Methodology (5):

• Cases were sub-classified to explore the causal or contributory factors in anaesthesia related mortality

• Subcategory classification was applied regardless of the patient’s condition prior to surgery

• Medical condition contributed substantially to death, subcategory H was applied

• No factor under the control of the anaesthesiologist that could or should have been done better, cases were then classified as subcategory G

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Causal or contributory factors in anaesthesia related mortality (subcategory)

A. Pre-operative

(i) Assessment This may involve failure to take an adequate history or perform an adequate examination or to undertake appropriate investigation or consultation or make adequate assessment of the volume status of the patient in an emergency. Where this is also a surgical responsibility the case may be classified in Category 3 above.

(ii) Management This may involve failure to administer appropriate therapy or resuscitation. Urgency and the responsibility of the surgeon may also modify this classification.

*Note that it is usual for more than one factor to be identified in the case of anaesthesia attributable death.

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Causal or contributory factors in anaesthesia related mortality (subcategory)

B. Anaesthesia Technique (i) Choice or application There is inappropriate choice of technique in circumstances where it is contraindicated or by the incorrect application of a technique which was correctly chosen. (ii) Airway maintenance There is inappropriate choice of artificial airway or failure to maintain Including or provide adequate protection of the airway or to recognize pulmonary misplacement or occlusion of an artificial airway. aspiration (iii) Ventilation Death is caused by failure of ventilation of the lungs for any reason. This would include inadequate ventilator settings and failure or reinstitute proper respiratory support after deliberate hypoventilation (e.g. bypass). (iv) Circulatory support Failure to provide adequate support where there is haemodynamic instability, in particular in relation to techniques involving sympathetic blockade.

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Causal or contributory factors in anaesthesia related mortality (subcategory)

C. Anaesthesia Drugs (i) Selection Administration of a wrong drug or one which is contraindicated or inappropriate. This would include “syringe swap” errors. (ii) Dosage This may be due to incorrect dosage, absolute or relative to the patient’s size, age and condition and in practice is usually an overdose. (iii) Adverse drug This includes all fatal drug reactions both acute such as anaphylaxis reaction and the delayed effects of anaesthesia agents such as the volatile agents. (iv) Inadequate This would include relaxant, narcotic and tranquillising agents reversal where reversal was indicated. (v) Incomplete e.g. prolonged coma. recovery

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Causal or contributory factors in anaesthesia related mortality (subcategory)

D. Anaesthesia Management (i) Crisis management Inadequate management of unexpected occurrences during anaesthesia or in other situations, which, if uncorrected, could lead to death or severe injury. (ii) Inadequate Failure to observe minimum standards as enunciated in the HKCA guidelines monitoring and policy documents or to undertake additional monitoring when indicated e.g. use of a pulmonary artery catheter in left ventricular failure. (iii) Equipment failure Death as a result of failure to check equipment or due to failure of an item of anaesthesia equipment. (iv) Inadequate Failure to provide adequate resuscitation in an emergency situation resuscitation (v) Hypothermia Failure to maintain adequate body temperature within recognized limits

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Causal or contributory factors in anaesthesia related mortality (subcategory)

E. Post-operative (i) Management Death as a result of inappropriate intervention or omission of active intervention by the anaesthetist or a person under their direction (e.g. Recovery or pain management nurse) in some matter related to the patient’s anaesthesia, pain management or resuscitation. (ii) Supervision Death due to inadequate supervision or monitoring. The anaesthetist has ongoing responsibility but the surgical role must also be assessed. (iii) Inadequate Death due to inadequate management of hypovolaemia or resuscitation hypoxaemia or where there has been a failure to perform proper cardiopulmonary resuscitation.

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Causal or contributory factors in anaesthesia related mortality (subcategory)

F. Organisational

(i) Inadequate These factors apply whether the anaesthetist is a trainee, a non- supervision, specialist or a specialist undertaking an unfamiliar procedure. inexperience The criterion of adequacy of supervision of a trainee is based on or assistance the HKCA Guidelines and Policy documents on supervision of trainees.

(ii) Poor organization Inappropriate delegation, poor rostering and fatigue contributing to a of the service fatality.

(iii) Failure of Poor communication in perioperative management and failure to interdisciplin anticipate need for high dependency care. ary planning

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Causal or contributory factors in anaesthesia related mortality (subcategory)

G. No Correctable Factor Identified Where the death was due to anaesthesia factors but no better technique could be suggested.

H. Medical Condition of the Patient Where it is considered that the medical condition was a significant factor in the anaesthesia related mortality

19 8 May 2007 Anaesthesia Related Mortality 2003-2005

Causal or contributory factors in anaesthesia related mortality in 2003 to 2005

2003 2004 2005 Total

A PRE-OPERATIVE 2 3 6 11 (17.2%)

i. Assessment 1 2 5 8

ii. Management 1 1 1 3

20 8 May 2007 Anaesthesia Related Mortality 2003-2005 Causal or contributory factors in anaesthesia related mortality in 2003 to 2005 (Anaesthesia - 22 out of 64 factors, 34.4%)

2003 2004 2005 Total B ANAESTHESIA TECHNIQUE 2 6 5 13 i. Choice of application 0 1 0 1 ii. Airway maintenance 2 2 1 5 iii. Ventilation 0 0 0 0 iv. Circulatory support 0 3 4 7 C ANAESTHESIA DRUGS 2 0 1 3 i. Selection 0 0 0 0 ii. Dosage 2 0 1 3 iii. Adverse event 0 0 0 0 iv. Incomplete reversal 0 0 0 0 v. Inadequate recovery 0 0 0 0 D ANAESTHESIA MANAGEMENT 1 2 3 6 i. Crisis management 1 0 0 1 ii. Inadequate monitoring 0 1 3 4 iii. Equipment failure 0 0 0 0 iv. Inadequate resuscitation 0 1 0 1 v. Hypothermia 0 0 0 0 21 8 May 2007 Anaesthesia Related Mortality 2003-2005

Causal or contributory factors in anaesthesia related mortality in 2003 to 2005

2003 2004 2005 Total

E POST-OPERATIVE 4 2 4 10 (15.6%) i. Management 2 1 3 6 ii. Supervision 0 0 0 0 iii. Inadequate resuscitation 2 1 1 4 F ORGANISATIONAL 1 0 3 4 (6.25%) i. Inadequate supervision or assistance 0 0 1 1 ii. Poor organisation 0 0 1 1 iii. Poor planning 1 0 1 2 G NO CORRECTABLE FACTOR 2 0 2 4 H MEDICAL CONDITION OF PATIENT A 4 4 5 13 (20.3%) SIGNIFICANT FACTOR

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Number of mortalities classified in each category

Category Number of cases

(Total 23)

1 10 (43.5%)

2 6

3 7

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Results:

• More male than female patients

• Most anaesthesia related deaths were found in patients over 70 years of age

• Patients with American Society of Anesthesiology (ASA) physical status class 3 or above were also at risk

• Anaesthesiologsists of all grades were involved

• More patients undergoing emergency and long complex procedures

• All patients had general anaesthesia except two who had subarachnoid block.

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Figure 1. Gender distribution in anaesthesia related deaths

Male, 14

Fem ale, 9

25 8 May 2007 Anaesthesia Related Mortality 2003-2005

Results:

• More male than female patients

• Most anaesthesia related deaths were found in patients over 70 years of age

• Patients with American Society of Anesthesiology (ASA) physical status class 3 or above were at risk

• Anaesthesiologsists of all grades were involved

• More patients undergoing emergency surgeries and long complex procedures

• All patients had general anaesthesia except two who had subarachnoid block.

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Figure 2. Age distribution in anaesthesia related deaths (> 70 Years of age, 78.3%)

10 9 8 7 6 5 4 3

Number of patients Number 2 1 0 <50 51-60 61-70 71-80 81-90 >90

Age (years)

27 8 May 2007 Anaesthesia Related Mortality 2003-2005

Results:

• More male than female patients

• Most anaesthesia related deaths were found in patients over 70 years of age

• Patients with American Society of Anesthesiology (ASA) physical status class 3 or above were at risk

• Anaesthesiologsists of all grades were involved

• More patients undergoing emergency surgeries and long complex procedures

• All patients had general anaesthesia except two who had subarachnoid block.

28 8 May 2007 Anaesthesia Related Mortality 2003-2005

Figure 3. Level of risk of patients by American Society of Anesthesiology (ASA) Physical Status Classification System (> ASA 3, 78.3%)

16 14 12 10 8 6 4 Number of patients Number 2 0 12345 ASA physical status

29 8 May 2007 Anaesthesia Related Mortality 2003-2005

Results:

• More male than female patients

• Most anaesthesia related deaths were found in patients over 70 years of age

• Patients with American Society of Anesthesiology (ASA) physical status class 3 or above were at risk

• Anaesthesiologsists of all grades were involved

• More patients undergoing emergency surgeries and long complex procedures

• All patients had general anaesthesia except two who had subarachnoid block.

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Figure 4. Experience of the anaesthesiologists involved

16 14 12 10 8 6 4 Number of patients 2 0 Trainee/Service Specialists Residents

31 8 May 2007 Anaesthesia Related Mortality 2003-2005

Results:

• More male than female patients

• Most anaesthesia related deaths were found in patients over 70 years of age

• Patients with American Society of Anesthesiology (ASA) physical status class 3 or above were also at risk

• Anaesthesiologsists of all grades were involved

• More patients undergoing emergency surgeries and long complex procedures

• All patients had general anaesthesia except two who had subarachnoid block.

32 8 May 2007 Anaesthesia Related Mortality 2003-2005

Figure 5. Urgency of surgery

Ele ct ive , 9 Emergency, 14

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Figure 6. Complexity of surgery (Major or ultramajor, 82.6%)

18 16 14 12 10 8 6

Number of patients Number 4 2 0 Minor Intermediate Maj or Ultramaj or Complexity of surgery

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Figure 7. Duration of operation (> 2 hours, 60.9%) 8

7

6

5

4

3

2 Number of patients 1

0 <1 1 to 2 2 to 4 4 to 8 >8 Duration of surgery (hours)

35 8 May 2007 Anaesthesia Related Mortality 2003-2005

Results:

• Urgent or emergency surgery has a higher anaesthesia related mortality rate

• 3 out of 23 cases or 3 out of the 14 emergency operations were performed during the night

• Vigilance is expected to be low and less technical support is available

36 8 May 2007 Anaesthesia Related Mortality 2003-2005

Figure 8. A. Time of all operations Figure 8 B. Time of emergency operations

A. All operations B. Emergency operations only

Night time, 3 Night time, 3

Day time , 11

Day time , 20

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Figure 9. Types of hospital (T=0.77, M=0.42, I=0.47, D=0.81 per 10,000 Anaesthetics)

8 7

6

5 4

3 2 Number of patients 1 0 Teaching Major Interm ediate Dis tr ict hospital hospital hospital hospital

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Figure 10. Location of anaesthesia related deaths OR = Operating Room; PACU = Post Anaesthesia Care Unit; ICU/HDU = / High Dependency Unit

14

12

10

8

6

4 Number of patients Number 2

0 OR PACU ICU/HDU Ward Location of anesthesia related deaths

39 8 May 2007 Anaesthesia Related Mortality 2003-2005 9 Figure 11. Types of operations or procedures. ENT/H&N8 = Otolaryngorhinology / head and neck surgery

7

6

5

4

3

Number of patientsNumber 2

1

0 ) l ic y N e t a ar r nal s en in l e i H& Eye cu g m T/ ther Renal Gyna O dom othorac Vas Urology EN Ab di -abdo anagem Orthopaedics on Non-invasive M Car Neurosur n ( ral Pai n Gene 40 8 May 2007 Anaesthesia Related Mortality 2003-2005

Most likely causes of death amongst the 23 anaesthesia related deaths

Number of deaths Diagnosis

Acute coronary syndrome 9

Aspiration pneumonia 6

Hypovolaemia / uncontrolled bleeding 2

Respiratory failure 1

Hyperkalaemia 1

Congestive cardiac failure 1

High spinal anaesthesia 1

Relative drug overdose 1

Cerebral vascular accident 1

Total 23 41 8 May 2007 Anaesthesia Related Mortality 2003-2005

Results:

• 23 anaesthesia related deaths among the HA hospitals during the triennium, 2003-2005

• The incidence of anaesthesia related mortality was therefore 1 in 16,277 or 0.614 per 10,000 anaesthetics (95% CI: 0.39-0.92)

• This figure is comparable to those recently reported in other parts of the world

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Discussion:

• Large variation in the incidence of anaesthesia related death among different surveys

• Due to the methodology used in these studies

• Many surveys relied on voluntary reporting (biased with under reporting)

• Some studies defined anaesthesia related deaths as those occurring within 24 hours after surgery and may have missed anaesthetic injury that result in death few days later

• Many previous reports it is also problematic in counting the actual number of anaesthetics delivered

• In our audit, reporting of death to the Births and Deaths Registry is mandatory, therefore it is possible to capture all deaths within a specific time after surgery accurately. We also reviewed and scrutinised all death reports in a standardised manner. The classification of death was defined a piroi. Co-ordinators and panel members deliberated on each case independently (accurate) 43 8 May 2007 Anaesthesia Related Mortality 2003-2005

Table 7. Anaesthesia related mortality in other countries.

No of anaesthetics Incidents per 10,000 Country Year of audit performed anaesthetics Hong Kong 2003-2005 374,373 0.61 Australia,9 2000-2002 7,650,000 0.18 Netherlands6 1995-1996 869,483 1.37 Taiwan7 2002 486,932 1.7 Japan8 1994-1998 2,363,038 0.21 Japan14 2001 1,284,957 0.1 Thailand11 2003-2004 163,403 5.75 France10 1999 7,756,121 0.54 England3 1987 485,850 7.4 Brazil13 1996-2005 53,718 1.12 Sweden4 1979-1989 262,850 0.27 Average 1.75

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Discussion:

• Large variation in the incidence of anaesthesia related death among different surveys

• Due to the methodology used in these studies

• Many surveys relied on voluntary reporting (biased with under reporting)

• Some studies defined anaesthesia related deaths as those occurring within 24 hours after surgery and may have missed anaesthetic injury that result in death few days later

• Many previous reports have problem with counting the actual number of anaesthetics delivered

• In our audit, reporting of death to the Births and Deaths Registry is mandatory, therefore it is possible to capture all deaths within a specific time after surgery accurately

• We also reviewed and scrutinised all death reports in a standardised manner 45 8 May 2007 Anaesthesia Related Mortality 2003-2005

Discussion:

• Identification of contributing factors is important as it highlights the areas for further improvement

• Information also allows us to look at the anaesthetic techniques and other contributory factors more critically

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Discussion:

• Critical analysis of these cases

• Produce useful practice guidelines

• Improve our anaesthetic skills and knowledge

• Only covered HA hospitals

• Comprehensive audit for all the anaesthetic procedures (HA and private) to reveal an accurate incidence of anaesthesia related mortality in Hong Kong 47 8 May 2007 Anaesthesia Related Mortality 2003-2005

Conclusion:

• First report of anaesthesia related mortality

• Triennium 2003 to 2005

• Incidence 1 in 16,277

• 0.614 per 10,000 anaesthetics

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Thank you

Q&A

49 8 May 2007