ICU shift related effects on sleep, fatigue and alertness levels.

BACKGROUND: Shift work may lead to suboptimal sleep resulting in impaired alertness, and lowered performance levels, all of which can lead to medical errors. AIMS: To examine fatigue, sleepiness and behavioural alertness prospectively in a tertiary level Australian intensive care unit (ICU). METHODS: All full-time doctors providing 24-h resident cover on a 12-h day and 12-h night shift roster were invited to participate in this study. Data collected included Epworth Sleepiness Scale (ESS), sleep and awake history, Samn-Perelli Fatigue (SPF) Scale, Karolinska Sleepiness Scale (KSS) and iOS-based Psychomotor Vigilance Test (behavioural alertness). Data about medical emergency team (MET) shifts were collected separately as they were perceived to be busier shifts. RESULTS: Twenty-nine ICU doctors participated in this study for a consecutive 6-week period. At baseline the median (interquartile range (IQR)) ESS was 5 (3-9). Day shift leads to an increase in fatigue and sleepiness (both P < 0.01). Night shift leads to worsening in fatigue, sleepiness and psychomotor vigilance (all P < 0.01). MET shifts had a lower psychomotor vigilance than non-MET shifts. The difference in the psychomotor vigilance was mostly due to the difference in recorded lapses and response time. CONCLUSIONS: Shift work ICU doctors experience high levels of fatigue and sleepiness. Night shifts also lead to decreased vigilance. This is even more evident in doctors working MET shifts. These factors may lead to errors. Optimal rostering may reduce these effects and improve patient safety.

Utility of atrial temporary pacing as an acute treatment for bradyarrhythmias and tachyarrhythmias in the intensive care setting with preservation of atrioventricular synchrony.

Temporary pacing is often used as an acute treatment of bradyarrhythmias and suppression of tachyarrhythmias. In patients with cardiogenic shock, loss of atrioventricular synchrony may worsen cardiovascular haemodynamics. We present a series where temporary right atrial pacing was used as an acute treatment for both bradyarrhythmias and tachyarrhythmias.

Mobile intensive care services in rural South Australia.

In the 12 years from 1984 to 1995, Adelaide-based mobile intensive care teams transported 4443 critically ill patients from rural areas in South Australia and adjacent States to tertiary-level hospitals in Adelaide. The SA Ambulance Service undertook communications, support staffing and deployment of transport. Average radial distances in 819 road missions were 71 km, in 808 helicopter missions 122 km, and in 2777 fixed-wing aircraft missions 398 km. The largest groups of patients were neonates (23%) and those with trauma (25%). Rural hospitals made 96% of the requests for intensive care transport; 4% came from ambulance or other emergency service crews at accident locations. Emergency surgical or operative obstetrical procedures were performed on 2.7% of patients before transport. One hundred and thirteen patients (2.5%) died during resuscitation or transport, with one death deemed to be preventable.

Group A streptococcal fasciitis.

OBJECTIVE: To review the current understanding of group A streptococcal fasciitis; the different bacterial serotypes, the role of superantigens, antibiotic and other therapies, and transmission to house hold contacts and health care workers. DATA SOURCES: Articles and published abstracts on the mechanisms and management of group A streptococcal fasciitis. SUMMARY OF REVIEW: The development of streptococcal fasciitis depends on the inoculation of a susceptible individual (i.e. one who has not been previously exposed to that particular serotype or superantigen) with a virulent streptococcus that has the ability to produce superantigens. The superantigens produce an excessive stimulation of the immune system, with a subsequent outpouring of inflammatory cytokines causing the multiorgan failure that characterises both streptococcal necrotising fasciitis as well as streptococcal toxic shock syndrome. Effective management of streptococcal necrotising fasciitis requires an early diagnosis, appropriate surgery, administration of clindamycin (600 mg/70 kg i.v. 6-hourly), penicillin G (1.2 g/70 kg i.v. 2 to 4-hourly), and polyvalent immunoglobulin (0.2 - 0.4 g/kg/day i.v. for 3 - 5 days). Household and health workers in close contact with the patient need to be warned to present to medical care early if they develop any signs of an infection. CONCLUSIONS: Necrotising fasciitis is a severe disorder which is commonly caused by group A streptococcus. Early diagnosis and effective management with surgery, antibiotics and polyvalent immunoglobulin will reduce mortality. Further studies concerning the risk of transmission of the organism to close contacts need to be performed.

Pressure-limited ventilation with permissive hypercapnia and minimum PEEP in saline-lavaged rabbits allows progressive improvement in oxygenation, but does not avoid ventilator-induced lung injury.

OBJECTIVE: To determine whether pressure-limited intermittent mandatory ventilation with permissive hypercapnia and positive end-expiratory pressure (PEEP) titrated to arterial oxygen tension (PaO2) prevents or reduces acute lung injury, compared to conventional ventilation, in saline-lavaged rabbits. DESIGN: Prospective randomised trial. SETTING: University animal laboratory. SUBJECTS: 18 New Zealand White rabbits. INTERVENTIONS: Following five sequential saline lung lavages, anaesthetised rabbits were randomly allocated in pairs to receive either of two ventilation protocols using intermittent mandatory ventilation. The study group had peak inspiratory pressure limited to 15 cm H2O and arterial partial pressure of carbon dioxide (PaCO2) was allowed to rise. The control group received 12 ml/kg tidal volume with rate adjusted for normocarbia. PEEP and fractional inspired oxygen (FIO2) were adjusted to maintain, PaO2 between 8 and 13.3 kPa (60 and 100 mm Hg) using a predetermined protocol. At 10 h or following death, lung lavage was repeated and lung histology evaluated. MEASUREMENTS AND MAIN RESULTS: The mean increase in lavage cell counts and protein concentration and hyaline membrane scores were not significantly different between the groups. Oxygenation progressively improved more in the study group (p = 0.01 vs control for PaO2/FIO2 ratio and alveolar-arterial oxygen tension gradient (AaDO2)). PEEP was similar and the mean airway pressure higher in the control group, suggesting that this probably resulted from less ventilator-induced injury in the study group. Four deaths occurred in the control group (three due to pneumothorax and one to hypoxaemia) and none in the study group (p = 0.08). CONCLUSIONS: This ventilatory protocol may have failed to prevent lung overdistension or it may have provided insufficient PEEP to prevent injury in this model; PEEP greater than the lower inflection point of the pressure-volume curve has been shown to prevent injury almost entirely.

A register of individuals with inborn errors of lipoprotein metabolism and their families.

One hundred and fifty-five hyperlipidaemic families resident in the Christchurch and Dunedin areas were included on a computerised register with built in confidentiality safeguards. Investigation of the relatives of the 155 probands identified 519 with normal lipids and a further 381 with hyperlipidaemia. The presence of 536 hyperlipidaemic individuals in the population of the two areas indicates a frequency of at least 0.12% which extrapolates to approximately 3800 cases of familial hyperlipidaemia nationwide. Our findings suggest that less than half of these are likely to have been detected. The most common condition was the mendelian dominant disorder familial hypercholesterolaemia found in 108 families. The register has been used to facilitate detection of further cases of familial hyperlipidaemias and appropriate counseling as well as for detecting and reassuring normal relatives. It also facilitates the long term study of the treatment of the affected individuals.