Antecedents to hospital deaths

BACKGROUND

Recent studies have suggested there are a large number of potentially preventable deaths in Australian hospitals.

AIM

This study aimed to document antecedent factors in hospital deaths in an attempt to identify potentially preventative factors.

METHODS

The study was conducted at three separate acute hospitals. Demographics of all deaths were recorded over a 6-month period as well as antecedent factors present within 0-8 and 8-48 h of all deaths including vital sign abnormalities, cardiorespiratory arrests and admission to intensive care. Separate analysis was performed on 'not for resuscitation' deaths.

RESULTS

There were a total of 778 deaths, of which 549 (71%) were 'not for resuscitation'. There were 171 (22%) deaths preceded by arrest and 160 (21%) preceded by admission to intensive care. Of the remaining deaths, 30% had severely abnormal physiological abnormalities documented. This incidence was 50% in the non-do not resuscitate (DNR) subgroup. Concern about the patient's condition was expressed in the patient's notes by attending nursing staff and junior medical staff in approximately one-third of non-DNR deaths. Hypotension (30%) and tachypnoea (17%) were the most common antecedents in the non-DNR deaths.

CONCLUSION

There is a high incidence of serious vital sign abnormalities in the period before potentially preventable hospital deaths. These antecedents may identify patients who would benefit from earlier intervention.

Rates of in-hospital arrests, deaths and intensive care admissions: the effect of a medical emergency team

OBJECTIVES

To evaluate the effectiveness of a medical emergency team (MET) in reducing the rates of selected adverse events.

DESIGN

Cohort comparison study after casemix adjustment.

PATIENTS AND SETTING

All adult (> or = 14 years) patients admitted to three Australian public hospitals from 8 July to 31 December 1996. INTERVENTION STUDIED: At Hospital 1, a medical emergency team (MET) could be called for abnormal physiological parameters or staff concern. Hospitals 2 and 3 had conventional cardiac arrest teams.

MAIN OUTCOME MEASURES

Casemix-adjusted rates of cardiac arrest, unanticipated admission to intensive care unit (ICU), death, and the subgroup of deaths where there was no pre-existing "do not resuscitate" (DNR) order documented.

RESULTS

There were 1510 adverse events identified among 50 942 admissions. The rate of unanticipated ICU admissions was less at the intervention hospital in total (casemix-adjusted odds ratios: Hospital 1, 1.00; Hospital 2, 1.59 [95% CI, 1.24-2.04]; Hospital 3, 1.73 [95% CI, 1.37-2.16]). There was no significant difference in the rates of cardiac arrest or total deaths between the three hospitals. However, one of the hospitals with a conventional cardiac arrest team had a higher death rate among patients without a DNR order.

CONCLUSIONS

The MET hospital had fewer unanticipated ICU/HDU admissions, with no increase in in-hospital arrest rate or total death rate. The non-DNR deaths were lower compared with one of the other hospitals; however, we did not adjust for DNR practices. We suggest that the MET concept is worthy of further study.

The need for undergraduate education in critical care. (Results of a questionnaire to year 6 medical undergraduates, University of New South Wales and recommendations on a curriculum in critical care)

One hundred and fifteen final year medical students of the University of New South Wales (UNSW) who were gathered together for mid-year lectures were asked to respond to a questionnaire which sought their perceptions of their knowledge of and competence in those skills required to prevent loss of life of patients with acute reversible life-threatening illnesses. There were 101 responders (88% response rate). A high proportion of students lacked practical experience of many of the skills or had not witnessed some procedures. They lacked confidence in their ability to manage acute emergencies. The results were similar to those in a separate study of the perceptions of New South Wales interns and resident medical officers of their competencies at the beginning of their intern year. The authors concluded that undergraduate education in critical care had not kept pace with the rapid evolution of critical care practice and describe the development and implementation of an explicit vertical and horizontal curriculum of critical care in the undergraduate curriculum of the UNSW.

Early postoperative emergencies requiring an intensive care team intervention. The role of ASA physical status and after-hours surgery

To examine the risk factors of early postoperative emergencies that required an intensive care team intervention, a matched nested case-control study (34 cases and 126 controls) was conducted. Over a 17-month period, the incidence of early postoperative emergencies occurring within 48 h of surgery was 0.21% (95% confidence intervals (CI): 0.14%-0.30%). The intensive care team treated two cardiac arrests and three respiratory arrests. The major physiological changes which led to ward staff summoning an intensive care team were hypotension (13 cases) and a decreased level of consciousness (nine cases). Significant associations with early postoperative emergencies were high ASA (> or = IV) physical status grades (odds ratio: 4.51, 95% CI: 1.24-16.40) and surgery performed outside normal working hours (odds ratio: 4.40, 95% CI: 1.41-13.69). High-risk patients may benefit from a visit by a postoperative care team during the early postoperative period but this requires further evaluation.

Risk of unanticipated intraoperative events in patients assessed at a preanaesthetic clinic

PURPOSE

To determine the risk of unanticipated intraoperative events (UIE) in patients assessed at a preanaesthetic clinic compared with those not assessed at the clinic.

METHODS

Preoperative and intraoperative data were collected on 6130 elective surgical patients by procedural anaesthetists over a 12-month-period at an Australian tertiary referral hospital. The procedural anaesthetists rated the level of preparation and identified predefined unanticipated intraoperative events. A logistic regression model was used to identify significant risk factors of UIE and was further validated on another sample of 482 patients (one month) by a goodness-of-fit test.

RESULTS

Of the 6130 elective surgical patients, 2000 (33%) had been assessed at the preanaesthetic clinic. There was a greater proportion of ASA II to IV patients seen at the clinic than patients not assessed at the clinic (chi 2(3) = 689.92, P < 0.001). Nonclinic patients were more likely to be inadequately prepared than clinic patients (RRunadjusted = 1.61, 95% CI: 1.25 to 2.04, P < 0.001). The overall incidence of intraoperative events was 4.14% (95% CI: 3.64% to 4.64%). Despite adjusting for the preparation level, type of anaesthesia, admission category, ASA physical status and duration of anaesthesia, clinic patients were 1.94 (95% CI: 1.42 to 2.64) times more likely to experience an UIE than nonclinic patients (P < 0.001).

CONCLUSION

Although clinic patients were more often optimally prepared, their adjusted risk of UIE was higher than nonclinic patients. The procedural anaesthetist needs to be vigilant with these high risk patients, even if they have been assessed at a preanaesthetic clinic.

Interhospital transfers: decision-making in critical care areas

OBJECTIVES

To evaluate the training of clinical staff in the use of interhospital transfer guidelines and to examine the underlying decision-making behavior in organizing patient transfers between hospitals.

DESIGN

Prospective assessment of clinical scenarios, given before (time 1), immediately after (time 2), and 3 months after (time 3) a program informing clinical staff about the use of interhospital transfer guidelines.

SETTING

Three emergency departments and one intensive care unit at three hospitals and a medical retrieval service in Sydney, Australia.

SUBJECTS

Physicians, nurses, and a paramedic working in critical care areas and at a medical retrieval service.

MEASUREMENTS AND MAIN RESULTS

A questionnaire containing clinical scenarios was administered to clinical staff. There was a significant difference in mean scores for selecting the appropriate escort levels across time (F2,78 = 24.2; p < .01) and for participant's experience with interhospital transfer (F2,39 = 4.63; p = .02). Significant improvement in mean scores occurred between time 1 (7.55 +/- 1.84 and time 2 (9.48 +/- 1.47) (t41 = -6.21; p < .01). The improvement in selecting appropriate escorts was maintained at time 3 (mean score 9.86 +/- 2.01). The error rate for inappropriate assignment of low levels of escorts decreased from 35% (time 1) to 10% (time 2) and 14% (time 3). Using conjoint analysis, there were large variations in the decision-making behaviour between each time period. The relative importance of each factor in influencing the decision to organize an escort at time 3 were as follows: treatment (43%); physiology (29%); patient age (24%); and diagnosis (4%). The decision-making model observed at time 3 had a high predictive value (87%) as compared with the model at time 1 (48%).

CONCLUSION

Clinical staff can make informed and appropriate decisions by using standardized guidelines when organizing interhospital transfers.

The perioperative system: a new approach to managing elective surgery

A Perioperative Service has recently been introduced at liverpool hospital, a 460-bed university teaching hospital. This provides a co-ordinated system for managing all elective surgical patients from the time an admission booked until hospital discharge. This paper describes the patient assessment, structure and staff requirements, benefits of and problems encountered with this service. The patient's preoperative preparation occurs before hospital admission. Where possible, patients are admitted on the day of procedure, either as a day-only patient, or a day-of-surgery patient. Patients are initially admitted to a specifically designed Perioperative Unit, adjacent to the Operating Theatre Suite. Patients do not enter the surgical wards until after their operation. Planning of the hospital discharge process commences at the time of booking for operation. Introduction of the Perioperative Service was staged process commencing in mid-1992. The hospital admits approximately 6,400 elective surgery cases each year. From July 1992 to December 1994, day-only patients were approximately 45% of these cases. Day-of surgery admission patients increased from 6% to 35% of all cases over the same period. Approximately 22% of elective surgical cases were seen in the Perioperative Clinic. As the Perioperative Service became fully operational, the average length of stay for elective surgical procedures fell. There has been a reduction in the areas of cancellations due to unavailability of beds, inappropriate preparation of patients, and non-attendance of patients for booked procedures. Patient acceptance is high. The existence of a perioperative system facilitates the planning and management of elective surgery with maximum quality and efficiency.

The use of "quality-adjusted life years" (QALYs) to evaluate treatment in intensive care

This study examines the feasibility of using Quality-Adjusted Life Years (QALYs) to assess patient outcome and the economic justification of treatment in an Intensive Care Unit (ICU). 248 patients were followed for three years after admission. Survival and quality of life for each patient was evaluated. Outcome for each patient was quantified in discounted Quality-Adjusted Life Years (dQALYs). The economic justification of treatment was evaluated by comparing the total and marginal cost per dQALY for this patient group with the published cost per QALY for other medical interventions. 150 patients were alive after three years. Quality of life for most longterm survivors was good. Patient outcome (QALYs) was greatest for asthma and trauma patients, and least for cardiogenic pulmonary oedema. The tentative estimated cost-effectiveness of treatment varied from AUD $297 per QALY for asthma to AUD $2323 per QALY for patients with pulmonary oedema. This compares favourably with many preventative and non-acute medical treatments. Although the methodology is developmental, the measurement of patient outcome using QALYs appears to be feasible in a general hospital ICU.

The Medical Emergency Team

The concept of a Medical Emergency Team was developed in order to rapidly identify and manage seriously ill patients at risk of cardiopulmonary arrest and other high-risk conditions. The aim of this study was to describe the utilization and outcome of Medical Emergency Team interventions over a one-year period at a teaching hospital in South Western Sydney. Data was collected prospectively using a standardized form. Cardiopulmonary resuscitation occurred in 148/522 (28%) calls. Alerting the team using the specific condition criteria occurred in 253/522 (48%) calls and on physiological/pathological abnormality criteria in 121/522 (23%) calls. Survival rate to hospital discharge following cardiopulmonary arrest was low (29%), compared with other medical emergencies (76%).

Problems following discharge after intensive care

Intensive care units (ICUs) are now present in most acute care hospitals. While long-term studies on patients admitted to these units have been performed to identify mortality, functional outcome and quality of life, there is little information on the recovery period in the weeks immediately following discharge. The aim of this study was to identify and describe the sequelae found in patients at 3 months after leaving the ICU. The study was conducted over a 6-month period during 1991, in a university teaching hospital in Sydney, Australia. 54 patients with a length stay (LOS) of greater than 48 hours in the ICU were included. Each patient was interviewed in an outpatient clinic attached to the ICU. Information collected included pre-admission details, reason for admission, treatments provided and complications encountered. General health state, social and employment details, functional status, referral patterns since discharge and recollection of ICU stay were studied. The major findings indicated that many of the patients interviewed were returning towards near normal general health, but were suffering mild to moderate physical and psychosocial sequelae. In the majority of cases the problems were not incapacitating. The predominant complaints were minor to severe pain, sleeping difficulties, tiredness and breathlessness. Financial problems were reported by a small number of patients. Depression, irritability or a feeling of loneliness were present in over one-third of the group. More than half the patients required referral for further assessment. 34% of patients had no recollection of their ICU stay. 16 patients (29.6%) reported unpleasant memories including nightmares and hallucinations.(ABSTRACT TRUNCATED AT 250 WORDS)

Intra-abdominal pressure measurement using a modified nasogastric tube: description and validation of a new technique

OBJECTIVE

This study assessed the accuracy of an intragastric method of measuring intra-abdominal pressure (IAP).

DESIGN

Prospective sequential study with simultaneous paired measurement of gastric and urinary bladder pressures.

SETTING

Operating theatre, University Teaching Hospital.

PATIENTS

9 patients undergoing laparoscopic cholecystectomy were studied.

INTERVENTIONS

Intraperitoneal pressures were monitored during peritoneal insufflation at laparoscopy up to a pressure of 20 mmHg.

MEASUREMENTS AND RESULTS

Intra-abdominal pressure measurements were recorded simultaneously using a gastric balloon and urinary catheter. Gastric pressure may be up to 4 mmHg higher or 3 mmHg lower than urinary bladder pressure.

CONCLUSIONS

Intra-abdominal pressure can be measured easily in this new fashion, allowing a continuous pressure trend to be obtained without interfering with urinary output estimation.

Referral of surgical patients to an anaesthetic clinic: a decision-making analysis

Effective utilization of an anaesthetic clinic depends on appropriate referral of high-risk surgical patients. The decision-making behaviour of anaesthetists and nurses was examined to identify factors that influence the referral of patients to an outpatient anaesthetic clinic. Eleven consultant anaesthetists, seven anaesthetic trainees and sixteen nurses working in anaesthetic areas estimated the likelihood that they would refer patients for each of the 30 scenarios presented. The relative importance of each factor influencing the decision to refer as determined by the 34 participants were: type of procedure (22%), co-morbidities (18%), fitness (13%), history of anaesthetic problems (12%), medications (11%), age (10%), obesity (8%) and anxiety (6%). Indicative risk factors identified were aged 65 years or over, unable to climb more than two flights of stairs, presence of significant medical problems, gross obesity, history of anaesthetic problems, taking regular medications, scheduled for major surgery and expressed anxiety about the anaesthetic. There were large variations in the decision-making behaviour among health professional groups.

Fluid balance charts: do they measure up?

Many current nursing activities are performed without regular reviews of their usefulness. The recording of fluid gains and losses on a fluid balance chart is one such activity. This article explores the practice of fluid monitoring on the wards of a university teaching hospital.

Do nurses know when to summon emergency assistance?

At Liverpool Hospital in 1989, mortality from cardiopulmonary arrest was 71% in the general wards, and 64% in the Emergency department. In an attempt to identify and treat seriously ill patients before they progressed to cardiac arrest, a medical emergency team (MET) was established. The MET replaced the existing cardiac arrest team and comprised a nurse from the intensive care unit (ICU), a resuscitation registrar (an anaesthetics trainee), a medical registrar and a senior registrar from the ICU. The resuscitation registrar was the team leader. The calling criteria for the MET were based on predetermined physiological variables, abnormal laboratory results, and specific conditions or if nursing or medical staff were concerned by the patient's condition. A study was conducted 2 years following implementation of the MET system, to determine registered nurses' (RNs) opinions, knowledge and use of the system. A questionnaire distributed to 141 nurses rostered on the chosen study date revealed a positive attitude the MET, although there was a low awareness regarding the availability of the MET information booklet. 53% of nurses had called the MET in the last 3 months; all would call the team again in the same circumstances. The correct response in three of four hypothetical situations presented was to call the MET. The number of correct responses varied between scenarios from 17-73%. Hypotension did not appear to alert nurses to summon emergency assistance. Some nurses, despite the presence of severe deterioration and patient distress, called the resident rather than the MET.(ABSTRACT TRUNCATED AT 250 WORDS)

Tests of six continuous flow CPAP devices

Six continuous flow CPAP devices were tested for pressure fluctuation and stability of inhaled oxygen concentration under conditions of simulated respiration. Four of the systems, the Ambu, Auspap, Downs'-Vital Signs and the Dräger are commercially available and two, the Prince Henry (PHH) and the Prince of Wales (POW) systems were assembled from Bird respirator parts, which were available in the respective Intensive Care Units. All appeared to be clinically effective. The Ambu offers convenience and economy of gases, the Dräger showed the least pressure fluctuations. Three of the four commercial systems lacked certain safety features which could more easily be added to the two non-commercial devices.

The end of the crystalloid era? A new approach to peri-operative fluid administration

The metabolic response to surgery causes sodium and water retention. It does not seem logical to pour crystalloid solutions into patients in the peri-operative period, particularly when these solutions can cause deterioration in lung function. Plasma volume must be maintained to prevent a decreased blood flow to vital organs such as the kidneys. Blood or colloid solutions, not crystalloid solutions, should be used for this purpose, since the latter are distributed throughout the whole extracellular space and are less effective in maintaining plasma volume. Water given as 5% dextrose should be given in minimal quantities to maintain intracellular hydration. Patients undergoing minor to moderate surgery when they are likely to be drinking within 24 hours do not usually require any intravenous infusion. Moreover, to administer intravenous fluids to these patients may cause harm. No fluid regimens should be inflexible and the patient's size, age and fluid losses should be taken into account.

Pressure infusors: variability in delivered infusion pressure

A pressure infusor was used to apply external pressures of 300, 250, 200, and 150 mm Hg to 500-ml plastic bags of saline. At constant applied pressure, 50-ml aliquots of saline were periodically withdrawn. The delivered pressures were less than the applied pressures, and the difference increased as the volume of saline within the bag decreased. This inherent pressure difference should be considered when the system is used with a continuous flush device.

Mediastinal emphysema simulating acute pericarditis

A case of extensive subcutaneous emphysema, retropneumoperitoneum and mediastinal emphysema is described. The mediastinal emphysema was associated with signs and symptoms of pericardial tamponade, and previously undocumented ECG changes, consistent with acute pericarditis, were noted.

Pneumoretroperitoneum

Pneumoretroperitoneum is rare, but sometimes seen in association with pneumoperitoneum as a result of barotrauma to the lungs. However, there have only been two previous cases of pneumoretroperitoneum without pneumoperitoneum following barotrauma. This case discusses several of the possible mechanisms by which this could occur and what associated signs, especially on chest X-ray, one should look for to confirm the aetiology of gas in the retroperitoneal space.

Study of diarrhea in critically ill patients

There has been an impression that diarrhea occurs commonly in seriously ill patients treated in ICUs. In view of the sparsity of published work on the problem, we embarked on a prospective study of all patients admitted to the ICU for more than 48 h over a 12-month period. Three factors were examined in detail: nasogastric feeding, cimetidine administration, and antibiotic treatment. Other factors also were considered, notably the nature of the underlying illness and the spread of a possible infective agent by cross-infection. There was a 41% incidence of diarrhea. A significant increase in the incidence of diarrhea occurred in patients on nasogastric feeding (p less than 0.01) and in those receiving cimetidine (p less than 0.05); there was no increased incidence in those receiving antibiotic therapy. The cytotoxin of Clostridium difficile was specifically looked for in all patients with diarrhea, but was not detected.

Severe coughing and pneumoperitoneum

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Colonization of the gastric contents in critically ill patients

In a study of 28 ventilated patients in the ICU, cimetidine was ineffective in maintaining gastric pH above 4. Quantitative and qualitative bacteriological examination of daily gastric aspirates showed that when the pH was above 4, there was rapid colonization with high counts of organisms, predominantly coliforms. Progressive colonization by yeasts, independent of pH, was noted in nearly one-half of the patients. Gastric colonization has possible implications in terms of crossinfection of development of aspiration pneumonia. As these are seriously ill patients with compromised gastrointestinal (GI) barriers and decreased immunity, the large numbers of bacteria or their endotoxins may contribute to the high incidence of septicemia.

Nitrous oxide concentrations in the dental surgery, Atmospheric and blood concentrations of personnel

Pollution in the dental outpatients surgery was assessed by measuring atmospheric nitrous oxide levels and comparing these with the venous blood concentrations in the operator-anaesthetist and his assistant. The effects of scavenging on both measurements have also been determined. Without scavenging the nitrous oxide level in the blood of the dentist was over four times that of the average anaesthetist working in an operating theatre. Some of the factors contributing to these high levels, and the effectiveness of scavenging are discussed.

Automatic ventilation with the Ayre's T-piece. A modification of the Nuffield Series 200 ventilator for neonatal and paediatric use

A simple modification to an existing adult ventilator has been designed to permit mechanical ventilation of neonates and small children with the Ayre's T-piece circuit. The Nuffield Anaesthesia Ventilator Series 200 has been modified by replacing the piston in the patient valve with a fixed leak. This arrangement avoids the problems of critical adjustment commonly encountered with other methods of converting adult ventilators to paediatric use, and allows the ventilator controls to be used normally. The ventilator has been assessed according to the proposed International Standards Organization specifications for the evaluation of the performance of lung ventilators, and the results are described in detail. The modified ventilator is shown to perform as a time-cycled pressure generator capable of delivering tidal volumes between 10 and 300 ml at frequencies from 10 to 85/minute. It is therefore ideally suited to neonatal and paediatric use.

Asynchronous independent lung ventilation (AILV)

A new technique is described for selective lung ventilation of patients with predominantly unilateral pulmonary pathology. Separate ventilators were used to inflate each lung via a double lumen endobronchial tube and no attempt was made to synchronize them. In three of the four cases, there was considerable improvement in respiratory function and radiographic appearance. In no case was there any cardiovascular depression. The use of a new endobronchial tube, the "broncho-cath", suitable for this technique is also described.