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Inadequate assessment of the airway and ventilation in acute poisoning. a need for improved education?
Resuscitation 40 (1999) 161 – 164
Inadequate assessment of the airway and ventilation in acute poisoning. a need for improved education? Joseph F. Cosgrove a, Alistair D. Gascoigne b,* a
John Hunter Hospital, Locked Bag 1, Hunter Region Mail Centre, NSW 2310, Australia b Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
Received 10 December 1998; received in revised form 21 December 1998; accepted 2 March 1999
Abstract Aims and objectives: To analyse the initial management of acute poisoning patients, and whether respiratory morbidity was related to inadequate assessment of airway and ventilation. Methods: A retrospective analysis of the assessment and resuscitation of a group of acute poisoning patients, as documented in the clinical records. Subjects and setting: Forty one patients admitted to either Intensive Care or Coronary Care Units in a UK teaching hospital with a diagnosis of acute poisoning, between 12 January 1997 and 21 January 1998. Standards: Advanced Life Support Guidelines were used to compare initial assessment. Criteria for intubation and ventilation described by Gentleman was used as the standard for intubation. Results: Thirty seven patients had documented Glasgow Coma Scales at the time of admission, 27 were managed appropriately; one exhibited signs of aspiration. Ten patients were judged to be managed inappropriately; six exhibited clinical signs of aspiration. Four patients had unidentified Glasgow Coma Scales. Conclusions: Increased emphasis on ‘Airway and Breathing’ remains necessary in medical education. Regional recommendations for the management of acute poisoning require ‘intubation guidelines’. Appropriate ward settings for monitoring such patients may pre-empt the onset of major respiratory problems. © 1999 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Advanced life support; Aspiration; Poisoning; Tracheal intubation
1. Introduction Self-poisoning, the most common cause of nontraumatic coma in patients under 35, accounts for up to 10% of acute medical admissions [1]. Respiratory depression due to a reduced level of consciousness may occur from either the direct central effects of the drugs taken, drug metabolite actions or from cardiovascular side-effects, notably arrhythmias and hypotension. This may be compounded by the fact that the drugs may have been taken in conjunction with alcohol. A reduction in conscious level puts the patient at an increased * Corresponding author. Tel.: + 44-191-2325131 ext: 24619; fax: +44-191-2275201.
risk of not only aspiration but also respiratory arrest. If significant morbidity and mortality is to be avoided a high index of suspicion for such complications is necessary. Several studies [1–6] have identified sub-optimal management of airway, breathing and circulation in a ward setting as major contributing factors to morbidity and prolonged admission to the Intensive Care Unit. Two of these studies have identified a lack of understanding of the predictable respiratory consequences of worsening coma, namely respiratory depression and ultimately respiratory arrest [3,7]. Patients at risk are being under diagnosed by those who may be unfamiliar with the assessment
0300-9572/99/$ - see front matter © 1999 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 3 0 0 - 9 5 7 2 ( 9 9 ) 0 0 0 2 5 - 8
162
J.F. Cosgro6e, A.D. Gascoigne / Resuscitation 40 (1999) 161–164
of the unconscious patient, early recognition of respiratory embarrassment may not occur as adequate oxygen saturation on pulse oximetry is often confused with adequate ventilation [8].
2. Subjects and methods The initial management of a group of patients subsequently admitted to either Coronary Care or Intensive Care for observation following episodes of acute poisoning was reviewed. Forty one patient episodes were identified between 12 January 1997 and 21 January 1998 (16 male and 18 female) age range 15 – 75. One male was admitted on six separate occasions and two females on four and two occasions, respectively. The study was a retrospective review of clinical record keeping in terms of initial assessment and management according to Advanced Life Support guidelines [9] and if potential or actual airway problems were present, whether their airway had been protected according to the criteria for intubation and ventilation laid down by Gentleman et al. [10] (Appendix A). The clinical findings of coma, loss of laryngeal reflexes and abnormal respiratory pattern are easily assessed and immediately available, unlike blood gas analysis which may invoke unnecessary delays. The aim was to look for clinical and radiological evidence suggestive of aspiration and whether its presence was influenced by these criteria. Patients details and diagnosis were retrieved from the admissions book of the respective units. Patients on coronary care and intensive care units were chosen as a simple means of identifying those who had been deemed sick enough at the time of initial assessment or who had run into trouble. The records of patients who were admitted to the medical admissions ward during the same period were not included in an attempt to limit the size of the review, there being over a thousand cases of self poisoning during this period.
3. Results Of the 41 patient episodes in our study, one was an accidental poisoning occurring at work. Twenty five had also consumed alcohol at the time of poisoning and therefore in addition to the sedative
effects of alcohol, there was the potential for alterations in both gastric volume and pH affecting the prognosis if aspiration occurred [11]. Four patients had no documentation of Glasgow Coma Scales on admission. None required intubation and ventilation. Their clinical courses ran as follows; two were noted to be ‘talking’ on admission and both were discharged to psychiatric care the following day. The other two suffered cardiovascular side-effects, although from the case notes it seems that this was a consequence of pre-hospital events (i.e. the overdose) rather than any failure to recognise potential problems on admission. One patient, having taken a mixture of digoxin, nifedipine and alcohol was hypotensive with pulmonary oedema and an ECG trace suggestive of an inferior myocardial infarction. On admission they were administered high flow oxygen, diuretics and a dobutamine infusion. The fourth patient had taken lisinopril, diltiazem, ibuprofen and gliclazide, requiring atropine, an isoprenaline infusion and eventually a temporary pacemaker. There was no documentation of any respiratory problems and consecutive chest radiographs did not show any evidence of aspiration. Of the 37 admissions with documented Glasgow Coma Scales during the course of their admission, 27 were managed according to the standards outlined earlier [9,10]. Eleven did not require any form of upper airway intervention and of the 16 who required tracheal intubation, only one exhibited signs suggestive off aspiration but this was prior to admission to hospital. According to the criteria outlined (Appendix A), on ten occasions patients received sub-optimal care in terms of protection of their upper airways. This was the result of either failure to call appropriate assistance (i.e. an anaesthetist) or failure of the appropriate help to recognise a compromised upper airway. Five had both clinical and radiological evidence of aspiration, with symptoms ranging from a mild chest infection treated with antibiotics and physiotherapy, to respiratory arrest and pulmonary oedema requiring positive pressure ventilation with 100% oxygen and up to 10 cm of positive end expiratory pressure. A sixth patient exhibited signs of a chest infection, although there was no radiological evidence of aspiration. The remaining four patients did not display any signs of aspiration, although they were still regarded as having received sub-optimal care according to
J.F. Cosgro6e, A.D. Gascoigne / Resuscitation 40 (1999) 161–164
guidelines [10,12]. Appropriate help was not requested on two occasions, and in the other two cases, patients with deteriorating levels of consciousness were transferred unintubated to the intensive care unit [10,12].
4. Discussion The study analysed the upper airway management of patients admitted to hospital following episodes of acute poisoning that required respiratory and cardiovascular monitoring. The standards used were criteria for resuscitation and intubation that have been incorporated into guidelines for the management of other comatose or semi-conscious patients. According to such criteria on ten occasions patients received sub-optimal care; on six of these occasions, patients suffered symptoms suggestive of aspiration, compared to one patient on the 27 occasions that appropriate care was received. Whilst the numbers in the study are small there was an increased incidence of aspiration in patients who were not intubated according to the recommendations modified from Gentleman et al. [10]. No mention of blood gas analysis has been made as it was not always performed and its timing in relation to intubation not being apparent from the case notes. Invariably blood gases being requested in the period immediately before or after intubation. The authors would argue the clinical assessment of coma, loss of laryngeal reflexes and identification of an abnormal respiratory pattern being more important in that it is quicker, blood gas analysis having inherent delays often not immediately being available in most Accident and Emergency departments. As a result of inadequate assessment, a number of patients with inadequately protected upper airways were at increased risk of the potentially life-threatening complications. On occasion this may to be due to a failure to appreciate problems in airway and breathing. Given the relative physical fitness and young age of self-poisoning patients (added to the knowledge that their actions are often impetuous) [1] there is a definite need for increased awareness amongst medical staff attending this group of patients. This raises a number of educational and management related issues. Other studies [2 – 7] have demonstrated a lack of under-
163
standing as to how ‘airway, breathing and circulation’ are the mainstays of basic physiological function; this review suggests that on occasion this is the case in our hospital. Therefore the need remains to educate medical staff in the ABC of Advanced Life Support [9]. Regional guidelines exist for the management of acute poisoning [13]. Whilst advocating an ‘A/B/ C’ approach, at times it is often unclear as to what constitutes adequate airway and ventilation; the only direct reference to tracheal intubation being a recommendation to intubate patients with inadequate gag reflexes receiving activated charcoal. An incorporation of ‘Intubation Guidelines’ into any document may therefore improve medical education and reduce the incidence of aspiration. Where such patients are observed and managed also raises a number of issues. Improvements in the management of acute cardiovascular disease has occurred with increased use of coronary care facilities [4,7] allowing for pre-emptive measures to be instituted early and thereby improving patient outcome. At present, debate centres on whether ‘Respiratory High Dependency Units’ can provide a similar role in monitoring respiratory function [14,15]. The argument for such units is strengthened by the fact that patients suffering cardiorespiratory arrest as a result of respiratory embarrassment have a worse outcome compared to those with cardiovascular disease. Patient care (in particular respiratory management) may therefore be improved if acute poisoning patients are monitored in such units.
5. Conclusions Although the number of patient episodes (41) in the study was small, problems were identified which can be modified to improve patient care, therefore concluding that: 1. Respiratory morbidity is increased in acute poisoning by poor understanding of airway and ventilation. Is this an educational problem? 2. Medical training for acute medicine at undergraduate and postgraduate level should continue to increase its emphasis on ‘airway, breathing and circulation’ [4,5,9]. An increased role in medical education for specialists in anaesthesia/intensive care can be identified.
164
J.F. Cosgro6e, A.D. Gascoigne / Resuscitation 40 (1999) 161–164
3. Regional recommendations [13] for the management of acute poisoning should include guidelines on when to intubate and ventilate. 4. Appropriate ward settings for the monitoring of such acute poisoning patients (e.g. a ‘respiratory high dependency unit’) [14,15] may help to pre-empt the onset of major respiratory problems. 5. Normal pulse oximetry is often equated with adequate ventilation and not under ventilation with impending respiratory arrest.
Appendix A. Indications for intubation and ventilation of coma patients
Immediately: Coma: not obeying commands, not speaking, not eye opening, i.e.: GCSB 8. Loss of protective laryngeal reflexes. Ventilatory insufficiency as judged by arterial blood gases: Hypoxaemia (PaO2 B 9 kPa on air orB13 kPa on oxygen) Hypercarbia (PaCO2 \ 6 kPa) Spontaneous hyperventilation causing PaCO2 B 3.5 kPa. Respiratory arrhythmia.Before transferring a patient (including within a hospital) Significantly deteriorating conscious level, even if not coma. Bilateral fractured mandible. Copious bleeding into mouth. Seizures. Gentleman et al. [10].
.
References [1] Collee GG, Hanson GC. The management of acute poisoning. Br J Anaesth 1993;70:562 – 73. [2] Schein RMH, Hazday N, Pena M, Ruben BH, Sprung CL. Clinical antecedents to in-hospital cardiopulmonary arrest. Chest 1990;98:1388 – 92. [3] Sax FL, Charlson ME. Medical patients at high risk of catastrophic deterioration. Crit Care Med 1987;15:510–5. [4] Franklin C, Matthew J. Developing strategies to prevent in hospital cardiac arrest. Analysing responses of physicians and nurses in the hours before the event. Crit Care Med 1994;22:244 – 7. [5] McQuillan P, Pilkington S, Allan A, Taylor B, Short A, Morgan G, Nielsen M, Barrett D, Smith G. Confidential enquiry into quality of care before admission to intensive care. Br Med J 1998;316:1853– 8. [6] Allan A, McQuillan PJ, Taylor BL, Nielsen MS, Collins CH, Short AIK, et al. Who sees the critically ill patient before ICU admission? Clin Intensive Care 1994;5:152. [7] Dubois RW, Brook RH. Preventable deaths: who, how often and why? Ann Intern Med 1988;109:582 – 9. [8] Stoneham MD, Saville GM, Wilson IH. Knowledge about pulse oximetry among medical and nursing staff. Lancet 1994;344:1339– 42. [9] Advanced Life Support Manual. Resuscitation Council (UK). Second Edition, London, 1994. [10] Gentleman D, Dearden M, Midgley S, Maclean D. Guidelines for the resuscitation and transfer of patients with acute head injury. Br Med J 1993;307:547 – 52. [11] Mendelson CL. The aspiration of stomach contents into the lungs during obstetric anaesthesia. Am J Obstet 1946;52:191 – 205. [12] Guidelines for the transport of the critically ill adult. Intensive Care Society Document, November 1997. [13] Wolfson Unit, Newcastle upon Tyne. Northern and Yorkshire Regional Health Authority Guidelines for the Management of Acute Poisoning, 3rd ed., April 1997. [14] Nava S, Confalonieri M, Rampulla C. Intermediate respiratory intensive care units in Europe: a European perspective. Thorax 1998;53:798 – 802. [15] Elliot MW, Baudouin SV. Respiratory intensive care in Europe: lessons for the UK. Thorax 1998;53:725–6.
.
Inadequate assessment of the airway and ventilation in acute poisoning. a need for improved education? Joseph F. Cosgrove a, Alistair D. Gascoigne b,* a
John Hunter Hospital, Locked Bag 1, Hunter Region Mail Centre, NSW 2310, Australia b Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
Received 10 December 1998; received in revised form 21 December 1998; accepted 2 March 1999
Abstract Aims and objectives: To analyse the initial management of acute poisoning patients, and whether respiratory morbidity was related to inadequate assessment of airway and ventilation. Methods: A retrospective analysis of the assessment and resuscitation of a group of acute poisoning patients, as documented in the clinical records. Subjects and setting: Forty one patients admitted to either Intensive Care or Coronary Care Units in a UK teaching hospital with a diagnosis of acute poisoning, between 12 January 1997 and 21 January 1998. Standards: Advanced Life Support Guidelines were used to compare initial assessment. Criteria for intubation and ventilation described by Gentleman was used as the standard for intubation. Results: Thirty seven patients had documented Glasgow Coma Scales at the time of admission, 27 were managed appropriately; one exhibited signs of aspiration. Ten patients were judged to be managed inappropriately; six exhibited clinical signs of aspiration. Four patients had unidentified Glasgow Coma Scales. Conclusions: Increased emphasis on ‘Airway and Breathing’ remains necessary in medical education. Regional recommendations for the management of acute poisoning require ‘intubation guidelines’. Appropriate ward settings for monitoring such patients may pre-empt the onset of major respiratory problems. © 1999 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Advanced life support; Aspiration; Poisoning; Tracheal intubation
1. Introduction Self-poisoning, the most common cause of nontraumatic coma in patients under 35, accounts for up to 10% of acute medical admissions [1]. Respiratory depression due to a reduced level of consciousness may occur from either the direct central effects of the drugs taken, drug metabolite actions or from cardiovascular side-effects, notably arrhythmias and hypotension. This may be compounded by the fact that the drugs may have been taken in conjunction with alcohol. A reduction in conscious level puts the patient at an increased * Corresponding author. Tel.: + 44-191-2325131 ext: 24619; fax: +44-191-2275201.
risk of not only aspiration but also respiratory arrest. If significant morbidity and mortality is to be avoided a high index of suspicion for such complications is necessary. Several studies [1–6] have identified sub-optimal management of airway, breathing and circulation in a ward setting as major contributing factors to morbidity and prolonged admission to the Intensive Care Unit. Two of these studies have identified a lack of understanding of the predictable respiratory consequences of worsening coma, namely respiratory depression and ultimately respiratory arrest [3,7]. Patients at risk are being under diagnosed by those who may be unfamiliar with the assessment
0300-9572/99/$ - see front matter © 1999 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 3 0 0 - 9 5 7 2 ( 9 9 ) 0 0 0 2 5 - 8
162
J.F. Cosgro6e, A.D. Gascoigne / Resuscitation 40 (1999) 161–164
of the unconscious patient, early recognition of respiratory embarrassment may not occur as adequate oxygen saturation on pulse oximetry is often confused with adequate ventilation [8].
2. Subjects and methods The initial management of a group of patients subsequently admitted to either Coronary Care or Intensive Care for observation following episodes of acute poisoning was reviewed. Forty one patient episodes were identified between 12 January 1997 and 21 January 1998 (16 male and 18 female) age range 15 – 75. One male was admitted on six separate occasions and two females on four and two occasions, respectively. The study was a retrospective review of clinical record keeping in terms of initial assessment and management according to Advanced Life Support guidelines [9] and if potential or actual airway problems were present, whether their airway had been protected according to the criteria for intubation and ventilation laid down by Gentleman et al. [10] (Appendix A). The clinical findings of coma, loss of laryngeal reflexes and abnormal respiratory pattern are easily assessed and immediately available, unlike blood gas analysis which may invoke unnecessary delays. The aim was to look for clinical and radiological evidence suggestive of aspiration and whether its presence was influenced by these criteria. Patients details and diagnosis were retrieved from the admissions book of the respective units. Patients on coronary care and intensive care units were chosen as a simple means of identifying those who had been deemed sick enough at the time of initial assessment or who had run into trouble. The records of patients who were admitted to the medical admissions ward during the same period were not included in an attempt to limit the size of the review, there being over a thousand cases of self poisoning during this period.
3. Results Of the 41 patient episodes in our study, one was an accidental poisoning occurring at work. Twenty five had also consumed alcohol at the time of poisoning and therefore in addition to the sedative
effects of alcohol, there was the potential for alterations in both gastric volume and pH affecting the prognosis if aspiration occurred [11]. Four patients had no documentation of Glasgow Coma Scales on admission. None required intubation and ventilation. Their clinical courses ran as follows; two were noted to be ‘talking’ on admission and both were discharged to psychiatric care the following day. The other two suffered cardiovascular side-effects, although from the case notes it seems that this was a consequence of pre-hospital events (i.e. the overdose) rather than any failure to recognise potential problems on admission. One patient, having taken a mixture of digoxin, nifedipine and alcohol was hypotensive with pulmonary oedema and an ECG trace suggestive of an inferior myocardial infarction. On admission they were administered high flow oxygen, diuretics and a dobutamine infusion. The fourth patient had taken lisinopril, diltiazem, ibuprofen and gliclazide, requiring atropine, an isoprenaline infusion and eventually a temporary pacemaker. There was no documentation of any respiratory problems and consecutive chest radiographs did not show any evidence of aspiration. Of the 37 admissions with documented Glasgow Coma Scales during the course of their admission, 27 were managed according to the standards outlined earlier [9,10]. Eleven did not require any form of upper airway intervention and of the 16 who required tracheal intubation, only one exhibited signs suggestive off aspiration but this was prior to admission to hospital. According to the criteria outlined (Appendix A), on ten occasions patients received sub-optimal care in terms of protection of their upper airways. This was the result of either failure to call appropriate assistance (i.e. an anaesthetist) or failure of the appropriate help to recognise a compromised upper airway. Five had both clinical and radiological evidence of aspiration, with symptoms ranging from a mild chest infection treated with antibiotics and physiotherapy, to respiratory arrest and pulmonary oedema requiring positive pressure ventilation with 100% oxygen and up to 10 cm of positive end expiratory pressure. A sixth patient exhibited signs of a chest infection, although there was no radiological evidence of aspiration. The remaining four patients did not display any signs of aspiration, although they were still regarded as having received sub-optimal care according to
J.F. Cosgro6e, A.D. Gascoigne / Resuscitation 40 (1999) 161–164
guidelines [10,12]. Appropriate help was not requested on two occasions, and in the other two cases, patients with deteriorating levels of consciousness were transferred unintubated to the intensive care unit [10,12].
4. Discussion The study analysed the upper airway management of patients admitted to hospital following episodes of acute poisoning that required respiratory and cardiovascular monitoring. The standards used were criteria for resuscitation and intubation that have been incorporated into guidelines for the management of other comatose or semi-conscious patients. According to such criteria on ten occasions patients received sub-optimal care; on six of these occasions, patients suffered symptoms suggestive of aspiration, compared to one patient on the 27 occasions that appropriate care was received. Whilst the numbers in the study are small there was an increased incidence of aspiration in patients who were not intubated according to the recommendations modified from Gentleman et al. [10]. No mention of blood gas analysis has been made as it was not always performed and its timing in relation to intubation not being apparent from the case notes. Invariably blood gases being requested in the period immediately before or after intubation. The authors would argue the clinical assessment of coma, loss of laryngeal reflexes and identification of an abnormal respiratory pattern being more important in that it is quicker, blood gas analysis having inherent delays often not immediately being available in most Accident and Emergency departments. As a result of inadequate assessment, a number of patients with inadequately protected upper airways were at increased risk of the potentially life-threatening complications. On occasion this may to be due to a failure to appreciate problems in airway and breathing. Given the relative physical fitness and young age of self-poisoning patients (added to the knowledge that their actions are often impetuous) [1] there is a definite need for increased awareness amongst medical staff attending this group of patients. This raises a number of educational and management related issues. Other studies [2 – 7] have demonstrated a lack of under-
163
standing as to how ‘airway, breathing and circulation’ are the mainstays of basic physiological function; this review suggests that on occasion this is the case in our hospital. Therefore the need remains to educate medical staff in the ABC of Advanced Life Support [9]. Regional guidelines exist for the management of acute poisoning [13]. Whilst advocating an ‘A/B/ C’ approach, at times it is often unclear as to what constitutes adequate airway and ventilation; the only direct reference to tracheal intubation being a recommendation to intubate patients with inadequate gag reflexes receiving activated charcoal. An incorporation of ‘Intubation Guidelines’ into any document may therefore improve medical education and reduce the incidence of aspiration. Where such patients are observed and managed also raises a number of issues. Improvements in the management of acute cardiovascular disease has occurred with increased use of coronary care facilities [4,7] allowing for pre-emptive measures to be instituted early and thereby improving patient outcome. At present, debate centres on whether ‘Respiratory High Dependency Units’ can provide a similar role in monitoring respiratory function [14,15]. The argument for such units is strengthened by the fact that patients suffering cardiorespiratory arrest as a result of respiratory embarrassment have a worse outcome compared to those with cardiovascular disease. Patient care (in particular respiratory management) may therefore be improved if acute poisoning patients are monitored in such units.
5. Conclusions Although the number of patient episodes (41) in the study was small, problems were identified which can be modified to improve patient care, therefore concluding that: 1. Respiratory morbidity is increased in acute poisoning by poor understanding of airway and ventilation. Is this an educational problem? 2. Medical training for acute medicine at undergraduate and postgraduate level should continue to increase its emphasis on ‘airway, breathing and circulation’ [4,5,9]. An increased role in medical education for specialists in anaesthesia/intensive care can be identified.
164
J.F. Cosgro6e, A.D. Gascoigne / Resuscitation 40 (1999) 161–164
3. Regional recommendations [13] for the management of acute poisoning should include guidelines on when to intubate and ventilate. 4. Appropriate ward settings for the monitoring of such acute poisoning patients (e.g. a ‘respiratory high dependency unit’) [14,15] may help to pre-empt the onset of major respiratory problems. 5. Normal pulse oximetry is often equated with adequate ventilation and not under ventilation with impending respiratory arrest.
Appendix A. Indications for intubation and ventilation of coma patients
Immediately: Coma: not obeying commands, not speaking, not eye opening, i.e.: GCSB 8. Loss of protective laryngeal reflexes. Ventilatory insufficiency as judged by arterial blood gases: Hypoxaemia (PaO2 B 9 kPa on air orB13 kPa on oxygen) Hypercarbia (PaCO2 \ 6 kPa) Spontaneous hyperventilation causing PaCO2 B 3.5 kPa. Respiratory arrhythmia.Before transferring a patient (including within a hospital) Significantly deteriorating conscious level, even if not coma. Bilateral fractured mandible. Copious bleeding into mouth. Seizures. Gentleman et al. [10].
.
References [1] Collee GG, Hanson GC. The management of acute poisoning. Br J Anaesth 1993;70:562 – 73. [2] Schein RMH, Hazday N, Pena M, Ruben BH, Sprung CL. Clinical antecedents to in-hospital cardiopulmonary arrest. Chest 1990;98:1388 – 92. [3] Sax FL, Charlson ME. Medical patients at high risk of catastrophic deterioration. Crit Care Med 1987;15:510–5. [4] Franklin C, Matthew J. Developing strategies to prevent in hospital cardiac arrest. Analysing responses of physicians and nurses in the hours before the event. Crit Care Med 1994;22:244 – 7. [5] McQuillan P, Pilkington S, Allan A, Taylor B, Short A, Morgan G, Nielsen M, Barrett D, Smith G. Confidential enquiry into quality of care before admission to intensive care. Br Med J 1998;316:1853– 8. [6] Allan A, McQuillan PJ, Taylor BL, Nielsen MS, Collins CH, Short AIK, et al. Who sees the critically ill patient before ICU admission? Clin Intensive Care 1994;5:152. [7] Dubois RW, Brook RH. Preventable deaths: who, how often and why? Ann Intern Med 1988;109:582 – 9. [8] Stoneham MD, Saville GM, Wilson IH. Knowledge about pulse oximetry among medical and nursing staff. Lancet 1994;344:1339– 42. [9] Advanced Life Support Manual. Resuscitation Council (UK). Second Edition, London, 1994. [10] Gentleman D, Dearden M, Midgley S, Maclean D. Guidelines for the resuscitation and transfer of patients with acute head injury. Br Med J 1993;307:547 – 52. [11] Mendelson CL. The aspiration of stomach contents into the lungs during obstetric anaesthesia. Am J Obstet 1946;52:191 – 205. [12] Guidelines for the transport of the critically ill adult. Intensive Care Society Document, November 1997. [13] Wolfson Unit, Newcastle upon Tyne. Northern and Yorkshire Regional Health Authority Guidelines for the Management of Acute Poisoning, 3rd ed., April 1997. [14] Nava S, Confalonieri M, Rampulla C. Intermediate respiratory intensive care units in Europe: a European perspective. Thorax 1998;53:798 – 802. [15] Elliot MW, Baudouin SV. Respiratory intensive care in Europe: lessons for the UK. Thorax 1998;53:725–6.
.