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Biomedical subjects

K Rowan

Publications and source records attributed to K Rowan.

33 records · Page 2Linked to original sources
PubMed2000

Consequences of discharges from intensive care at night.

BACKGROUND: It is generally believed that pressure for beds on intensive-care units (ICUs) has increased in the UK. This study used discharge at night as a proxy measure to investigate pressure. METHODS: Night was defined in two ways: "out of office hours' from 2200 to 0659 h and "the early hours of the morning" from 0000 to 0459 h. The rate of discharge at night was compared for 21 295 adult admissions to 62 ICUs covering the period 1995-98 with 10806 admissions to 26 ICUs covering the period 1988-90. With data solely from 1995-98, the consequences of discharge at night and premature discharge were investigated. FINDINGS: Overall, 2269 (21.0%) admissions did not survive the ICU in 1988-90 compared with 4487 (21.1%) in 1995-98. Of ICU survivors, 2.7% were discharged at night (2200-0659 h) in 1988-90 compared with 6.0% in 1995-98. In 1995-98, night discharges (2200-0659 h) had a higher crude (odds ratio 1.46, 95% CI 1.18-1.80) and case-mix adjusted (1.33, 1.06-1.65) ultimate hospital mortality. Higher odds ratios were observed when the definition of night was 0000-0459 h. Premature discharge was commoner at night, 42.6% vs 5.0% and its importance was apparent when incorporated into the logistic-regression model (premature discharge 1.35, 1.10-1.65; night discharge 1.17, 0.92-1.49). INTERPRETATION: Night discharges from ICU are increasing in the UK. This practice is of concern because patients discharged at night fare significantly worse than those discharged during the day. Night discharges are more likely to be "premature" in the view of the clinicians involved. The implication of these results is that many hospitals have insufficient intensive-care beds. In deciding whether or not to invest more resources in intensive care we must, however, consider the cost-utility of this particular service compared with other ways that additional resources could be used.

APACHE↗
PubMed2000

Calcium channel blockers for acute traumatic brain injury.

BACKGROUND: Acute traumatic brain injury is a major cause of death and disability. Calcium channel blockers have been used in an attempt to prevent cerebral vasospasm after injury, maintain blood flow to the brain and so prevent further damage. OBJECTIVES: To estimate the effects of calcium channel blockers in patients with acute traumatic brain injury and in a subgroup of brain injury patients with traumatic subarachnoid haemorrhage. SEARCH STRATEGY: Hand searching and electronic searching for randomized controlled trials available by October 1997. SELECTION CRITERIA: Randomized controlled trials in patients with all levels of severity of clinically diagnosed acute traumatic brain injury. DATA COLLECTION AND ANALYSIS: Two reviewers (JL and CG) independently assessed the identified studies for eligibility and extracted data from each study. Summary odds ratios were calculated using the Mantel-Haenszel method. MAIN RESULTS: Four RCTs were identified as eligible for inclusion in the systematic review. The effect of calcium channel blockers on the risk of death was reported in all RCTs. The pooled odds ratio for the four studies was 0.91 (95% confidence interval 0. 70 to 1.17). For the three RCTs that reported death and severe disability the pooled odds ratio was 0.85 (95% CI 0.68 to 1.07). In the two RCTs which reported the risk of death in a sub group of traumatic subarachnoid haemorrhage patients, the pooled odds ratio was 0.59 (95% CI 0.37 to 0.94). Three RCTs reported death and severe disability as an outcome in this subgroup, and the pooled odds ratio was 0.67 (95% CI 0.46 to 0.98). REVIEWER'S CONCLUSIONS: This systematic review of randomized controlled trials of calcium channel blockers in acute traumatic head injury patients shows that considerable uncertainty remains over their effects. The effect of nimodipine in a subgroup of brain injury patients with subarachnoid haemorrhage shows a beneficial effect, though the increase in adverse reactions suffered by the intervention group may mean that the drug is harmful for some patients.

Brain Injuries↗
PubMed1999

Identification of randomized controlled trials from the emergency medicine literature: comparison of hand searching versus MEDLINE searching.

STUDY OBJECTIVE: As part of an ongoing project to identify all the randomized controlled trials (RCTs) in the emergency medicine literature, in association with the Cochrane Collaboration, 2 discrete studies were undertaken; the first, to compare motives for active participation in hand searching of the literature by emergency medicine professionals, and the second, to compare hand searching with MEDLINE searching of a number of emergency medicine journals. METHODS: All listed members of the British Association for Emergency Medicine (BAEM) and the Society for Academic Emergency Medicine (SAEM) received a standard letter outlining the objectives of the project, with 1 of 3 headings assigned on an alternate basis. Recruited volunteers hand searched journals prioritized from the emergency medicine literature. Each issue of each journal was hand searched for RCTs. In addition, a comprehensive MEDLINE search was conducted for each journal. The yields of RCTs from the 2 searching methods were compared for all journals and for each journal individually. RESULTS: No clear motivation for participation in this work could be ascertained because of the low response rates from BAEM and SAEM (10.1% and 1.8%, respectively). Only 18 (29.0%) of the 62 journals identified were indexed by MEDLINE. In the 14 journals indexed by MEDLINE for which hand searching was completed, a total of 710 RCTs were identified by a combination of the 2 approaches; of these, 592 (83.4%) were identified by hand searching alone and 483 (68.0%) by MEDLINE searching alone. Both methods identified 365 (51. 4%) RCTs; hand searching revealed an additional 227 (32.0%) that were not identified by MEDLINE searching, and MEDLINE searching found 118 (16.6%) that were not identified by hand searching. The difference between the proportions identified by hand searching and by MEDLINE searching (15.4%; 95% confidence interval [CI], 12.7% to 17.9%) was statistically significant (McNemar's chi2 test, 1 df, 33. 8; P <.0001). This difference was not significant for 8 of the journals. CONCLUSION: The response rates from mailing to members of the relevant professional organizations letters requesting participation in this work were very low and suggested that such an approach was not cost-effective. However, no formal costing exercise was undertaken. Searching results showed that, in the 14 emergency medicine journals indexed by MEDLINE for which hand searching was completed, hand searching led to identification of additional RCTs (primary articles) not found through MEDLINE searching. However, hand searching, although statistically significantly better than MEDLINE searching, failed to identify some of the RCTs found by MEDLINE searching, suggesting that hand searching is not a "gold standard" method and that the dual approach, promoted by the Cochrane Collaboration, may be the optimal approach for journals indexed by MEDLINE.

Attitude of Health Personnel↗
PubMed1998

Classification trees. A possible method for iso-resource grouping in intensive care.

Classification and grouping of clinical data into defined categories or hierarchies is difficult in intensive care practice. Diagnosis-related groups are used to categorise patients on the basis of diagnosis. However, this approach may not be applicable to intensive care where there is wide heterogeneity within diagnostic groups. Classification tree analysis uses selected independent variables to group patients according to a dependent variable in a way that reduces variation. In this study, the influence of three easily identified patient attributes on their length of intensive care unit stay was explored using classification analysis. Two thousand five hundred and forty-five critically ill patients from three hospitals were classified into groups so that the variation in length of stay within each group was minimised. In 23 out of 39 terminal groups, the interquartile range of the length of stay was < or = 3 days.

Critical Care↗
PubMed1996

Identification of a bacterial inhibitor of protein kinases. Mechanism and role in host cell invasion.

We show that Escherichia coli produce a factor that inhibits the activity of tyrosine and serine/threonine protein kinases. The factor is a protein found in the periplasmic compartment and is also secreted into the culture medium. Using a particle concentration fluorescence immunoassay specific for tyrosine kinase activity and inhibition of the tyrosine kinase p56(lck), we purified this factor to apparent homogeneity. Analysis of trypsin-digested fragments by mass spectrometry identified the inhibitor as the bacterial periplasmic protein UDP-sugar hydrolase, an enzyme with potent and nonspecific 5'-nucleotidase activity. Overexpression of the enzyme in bacteria leads to coordinate increases in both 5'-nucleotidase and p56(lck) inhibitory activity, confirming the identity of the inhibitor. The kinase inhibitory activity appears to be due to the formation of adenosine, which we show is inhibitory for p56(lck), cAMP-dependent protein kinase, and casein kinase. Overexpression of UDP-sugar hydrolase leads to an increase in the recovery of enteropathogenic E. coli following infection of HeLa cell monolayers and corresponding alterations in tyrosine-phosphorylated host proteins. These results suggest that UDP-sugar hydrolase may be an important factor affecting host cell function following intracellular bacterial infection.

Adenosine↗
PubMed1995

Is there a relationship between the volume of work carried out in intensive care and its outcome?

This paper reports the results of a study of the association between volume of activity and patient outcome in 26 intensive care units in the United Kingdom. Hospital fatality rates showed a statistically significant (p = .016) negative association with volume. However, mean APACHE II scores, as a measure of the severity of case mix, were also negatively associated with volume (p = .021). Thus, one explanation of the lower death rates at higher volumes is that larger units admit less severely ill patients. For patients admitted immediately after surgery, the correlation between severity standardized mortality ratios and volume (while not significant, p < .1) suggests there may be a volume-output effect unexplained by severity.

APACHE↗