Evidence for separate disease phenotypes in intestinal Crohn's disease

BACKGROUND

This study investigated the hypothesis that separate phenotypes of Crohn's disease exist which display differing patterns of recurrence with a tendency to preservation of phenotype between serial operations.

METHODS

Some 483 abdominal operations (278 patients) were identified from a prospectively compiled database. Patterns of recurrence (reoperation) were analysed by Kaplan-Meier plots and log rank tests according to disease phenotype (perforated, stenosed or ulcerated). Serial operations were analysed by agreement of phenotype and microscopic features of disease using kappa statistics and correlation coefficients.

RESULTS

There was no significant difference in recurrence according to disease phenotype (median reoperation-free survival time 43.0, 50.2 and 47.9 months for perforated, stenosed and ulcerated types respectively; log rank chi(2) = 3.5, P = 0.18). There was poor agreement in phenotype between serial operations (kappa = 0.22 for first/second operation and kappa= 0.15 for second/third operation) and no significant correlation between pathological features was identified (r between -0.19 and 0.48).

CONCLUSION

No evidence was found for the existence of separate disease phenotypes with differing natural histories or underlying pathological characteristics.

A consensus driven method to measure the required number of intensive care nurses in Australia

This paper describes a methodology for determining the number of nurses required to staff Australia's intensive care unit (ICU) beds. The evidence used is level IV, that is the use of expert panel opinion, and it is the strongest and most accurate attempt yet to describe how Australia's ICU beds should be staffed with nurses. The researchers provide ratios of staffing applicable to a variety of situations that should be of use to ICU managers and hospital administrators. Equally, the broader calculations explaining the national supply and demand needs provide an easy to use approach and explanation suitable to health professionals, health administrators, policy advisors, governments, politicians and the broader community. Limitations of the approach and further recommendations are made to encourage future work in this area. Finally, a strong correlation between the number of available 'open' ICU beds in Australia and the number of nurses actually working in ICU at any given time is well demonstrated using the methodology outlined in this paper. Clarification of scope and terminology: This paper focuses on the nursing requirements of ICUs only; occasionally we use the word critical care nurse--this generally refers to those nurses who have completed a generic critical care nursing course but who, for the purposes of our study, are working in ICUs. Critical care units encompass ICUs but may also encompass recovery room, cardiothoracic units, coronary care, emergency departments and many other environments where critically ill patients are cared for and treated. This paper does not cover the broader scope of critical care units, only ICUs.

Can we predict who will return to a genitourinary clinic?

One hundred and eighty-eight first-time attenders at a genitourinary (GU) clinic were monitored to establish who returned following discharge after treatment. Thirty-six (19%) returned within 2 years with a new infection. The re-attenders did not differ significantly from the rest of the cohort by age, gender or occupation, nor did they differ in their sexual history and psychological variables. Re-attenders were significantly more likely to have consulted their general practitioner (GP) in the 6 months prior to their first clinic attendance.

Questionnaire on practices and priorities in neonatal care in Ireland

As part of a process of audit of neonatal practice, a questionnaire on clinical practice and priorities which need to be addressed was sent to all consultant neonatologists, and to a consultant paediatrician in all other units caring for newborn infants, in the Republic of Ireland. The response rate was 88% (22 out of 25 replied). Thirteen respondents specified greater than 24 weeks and/or greater than 500 grams as the criteria at which infants were resuscitated. Eleven routinely intubated very premature infants. Seven treated any infant intubated for respiratory distress syndrome with surfactant, and seven sometimes used prophylactic surfactant. Poor perfusion or low blood pressure was the most common criterion for volume expansion during the first hour, using albumen (15 of 22), fresh frozen plasma (10), whole blood (9), normal saline (20 and haemacell (1). Most (18 of 22) used steroids for established bronchopulmonary dysplasia. Oral feeds were generally begun "as soon as possible". Persistent foetal circulation was treated with various vasodilators, tolazoline (14 of 22), magnesium sulphate (8) and nitric oxide (4). The main local priorities noted are the need for more neonatally trained nursing and / or medical staff. Almost all respondents noted the need for a national neonatal transport system. While this summary reveals a considerable variation in clinical practice this variation reflects the lack of evidence on which to base clinical decision making. Where evidence exists from clinical trials considerable uniformity exists in clinical decision making and practice. This study highlights the need for continued audit of clinical practice and the essential role clinical research plays in informing decision making in practice.

A study of the references used in Cochrane protocols and reviews. Three bibles, three dictionaries, and nearly 25,000 other things

OBJECTIVES

To describe the types of report that are cited by protocols and reviews included in the Cochrane Database of Systematic Reviews.

METHODS

The citation for each reference included in the Cochrane protocols and reviews published in the Cochrane Database of Systematic Reviews in issue 1, 1999 of The Cochrane Library were categorized by reference type (e.g., journal article, conference proceeding, book chapter, personal communication, Cochrane review).

RESULTS

Of a total of 24,913 citations, 21,694 (87.1%) were references to journal articles. There was a significant difference between the proportion of references to studies that were journal articles (12,348 of 13,472; 91.7%) and the proportion of other references in this category (9,346 of 11,441; 81.7%).

CONCLUSION

The great majority of studies included in Cochrane reviews at the beginning of 1999 had been published as journal articles.

Carbon dioxide contributes to the beneficial effect of pressurization in a portable hyperbaric chamber at high altitude

Regional cerebral oxygenation (rSO2) and peripheral oxygen saturation (SpO2) have been studied in subjects inside a portable hyperbaric chamber at altitude during pressurization. The effects of the accumulation of carbon dioxide within the chamber on rSO2 and SpO2 have also been investigated. Three studies of cerebral regional oxygenation were undertaken, using near-IR spectroscopy, in subjects who had ascended to 3475 m in the Alps, 4680 m in the Andes or 5005 m in the Himalayas. At 3475 m and 5005 m the effects of the removal of inspired carbon dioxide by a soda lime scavenger were also studied. On pressurization of the chamber to 19.95 kPa, inspired carbon dioxide rose within the chamber from 0.03% (0.06 kPa) ambient to over 1% (1.3 kPa). At 5005 m, SpO2 rose from a baseline of 79.5% (S.D. 4.5%) to 95.9% (2.0%) (P<0.0001), and cerebral rSO2 rose from 64.6% (3.4%) to 69.4% (3.6%) (P<0.0001). The introduction of a soda lime CO2 scavenger into the breathing circuit resulted in a drop in SpO2 from 95.9% (2.03%) to 93.6% (2.07%) (P<0.001) and a fall in rSO2 from 69.4% (3.64%) to 68.5% (3.5%) (P<0.01). Chamber pressure was maintained throughout at 19.95 kPa. Similar changes were seen at the other altitudes. Cerebral rSO2 increased rapidly following pressurization at all three altitudes. Scavenging of inspired carbon dioxide was associated with a significant fall in cerebral rSO2 and SpO2, and we estimate that the contribution of carbon dioxide may account for up to one-third of the beneficial effect of the portable hyperbaric chamber.

Activation of postsynaptic 5-HT1A receptors by fluoxetine despite the loss of firing-dependent serotonergic input: Electrophysiological and neurochemical studies

Systemic doses of fluoxetine slow dorsal raphe cell firing by blocking the reuptake carrier located in the cell body region with the surplus 5-HT thus generated activating inhibitory autoreceptors. The concurrent actions of fluoxetine on postsynaptic receptors in raphe projection areas has not been as thoroughly investigated, although it is presumed that a reduction in cell firing should curtail these targeted effects. The goal of the present studies was to assess the degree of postsynaptic receptor activation obtained with fluoxetine and relate it to cell body autoreceptor activation and the level of extracellular 5-HT obtained at the nerve endings. Changes in firing rates of CA3 hippocampal neurons following systemic administration of fluoxetine were used as a marker of SSRI-dependent changes in postsynaptic 5-HT receptor activation; monitoring of unit activity of neurons in the dorsal raphe nucleus served to gauge the degree of serotonergic input in a parallel series of animals. Estimates of the corresponding changes in terminal 5-HT release in the CA3 region were analyzed by microdialysis. The results indicate that fluoxetine inhibits hippocampal cell firing in a dose-dependent manner (ED(50) = 4.4 mg/kg i.v.) and one sensitive to pretreatment with the 5-HT(1A) antagonist WAY-100,635. Within the same dose range, increases in hippocampal extracellular 5-HT approaching 300% above basal levels were achieved. Both the changes in hippocampal neuronal activity and extracellular 5-HT are evident at doses of fluoxetine in excess of that required to inhibit dorsal raphe cell firing (ED(50) = 1.1 mg/kg i.v.). Taken together, these data suggest that increases in extracellular levels of 5-HT on the order of that observed are sufficient to alter postsynaptic excitability and that this accumulation of synaptic 5-HT and the subsequent activation of postsynaptic 5-HT(1A) receptors are achievable despite loss of firing-dependent 5-HT release.

The HELLP syndrome: maternal and perinatal outcome

The HELLP syndrome is a rare condition with a variable presentation, and in general, the outlook for mother and baby is felt to be poor. The aims of this study were to determine the maternal and perinatal outcome in cases of the HELLP syndrome at the Rotunda hospital over a five-year period. A retrospective review of all cases of confirmed HELLP syndrome from 1/1/95 to 1/9/99 was undertaken. Antenatal, intrapartum and neonatal data and in particular, maternal and neonatal complications were recorded. There were 20 cases of HELLP syndrome over the 5-year period. Mean maternal age was 29.8 (19-43) years. 70% were nulliparous. 80% delivered within 24 hours of diagnosis. 85% were delivered by caesarean section. Mean gestation at delivery was 33.5 (24-41) weeks, 65% of which were preterm. 70% of the babies were admitted to the neonatal intensive care unit (NICU). Mean birth weight was 1923g (440-4640g). Mean length of stay was 23.8 (1-68) days. 40% developed respiratory distress syndrome (RDS) with a mean duration of ventilation for these infants of 2.4 (0.5-7) days. There were 2 perinatal deaths both of whom weighed <500g. 95% of women were admitted to the High Dependency Unit. There were no maternal deaths. The mean interval to resolution of laboratory indices to within normal reference ranges was 11 (2-30) days. Maternal morbidity was high, but short-term, with full resolution in all cases. Once the diagnosis was made, delivery was immediate. The neonatal morbidity was also high and was most closely related to the gestation at delivery.

Healing at skin graft donor sites dressed with chitosan

Chitosan is a derivative of chitin, extracted from the exoskeleton of lobsters, crabs and shrimps. As a semi-permeable biological dressing, it maintains a sterile wound exudate beneath a dry scab, preventing dehydration and contamination of the wound to optimise conditions for healing. In this study, evaluation of healing at split skin graft donor sites, dressed half with chitosan and half with a conventional dressing, showed that chitosan facilitated rapid wound re-epithelialisation and the regeneration of nerves within a vascular dermis. In addition, digital colour separation analysis of donor site scars demonstrated an earlier return to normal skin colour at chitosan-treated areas.

Development of a high-performance liquid chromatographic-mass spectrometric assay for the specific and sensitive quantification of Ro 64-0802, an anti-influenza drug, and its pro-drug, oseltamivir, in human and animal plasma and urine

Oseltamivir phosphate (Ro 64-0796/002) is a pro-drug of the anti-influenza neuraminidase inhibitor, Ro 64-0802, and as Tamiflu, has been developed for the treatment of both A and B strains of the disease. This paper describes an HPLC-MS-MS assay for both compounds in plasma and urine which fulfils all of the criteria for a good analytical method. It is sensitive with limits of quantification of 1 and 10 ng/ml for the pro-drug and active neuraminidase inhibitor, respectively. It is both accurate and precise with typical coefficients of variation from some 5,000 quality control samples of approximately +/-3 and +/-6%, respectively. Extensive stability studies have demonstrated the absence of significant problems associated with the decomposition of either compound, although ex vivo hydrolysis of Ro 64-0796 to Ro 64-0802 in rodent plasma has to be prevented by the use of the esterase inhibitor, dichlorvos.

Cerebral oxygenation at high altitude and the response to carbon dioxide, hyperventilation and oxygen. The Birmingham Medical Research Expeditionary Society

Cerebral oxygenation is likely to be of critical importance in determining function at high altitude. The present study has used the technique of near-IR spectroscopy to monitor changes in cerebral regional oxygenation in response to inhaled carbon dioxide, hyperventilation and supplementary oxygen on ascent to 4680 m over 3 days. At sea level, inhaled CO(2) resulted in a significant rise in cerebral regional oxygenation [from mean 69.6% (S.D. 2.4% to 71. 1+/-2.3%; means+/-S.D.; P<0.001). At 4680 m, CO(2) increased regional cerebral oxygenation (63.8+/-2.5% to 65.9+/-2.2%; P<0.001) and also increased peripheral oxygen saturation (75.1+/-6.1% to 83. 6+/-4.0%; P<0.001). Voluntary hyperventilation resulted in improved peripheral oxygen saturation at 2770 m, 3650 m and 4680 m, whereas cerebral regional oxygenation was reduced at sea level and at 2770 m, unchanged at 3650 m and increased at 4680 m. Supplementary oxygen (6 1itres/min) at 4680 m resulted in greater improvements in peripheral oxygen saturation (76.7+/-7.9% to 98.1+/-1.5%; P<0.001) and cerebral regional oxygenation (64.6+/-3.3% to 70.6+/-2.9%; P<0. 001) than were found with CO(2) or hyperventilation. We conclude that attempts to increase CO(2) inhalation or ventilation at high altitude are likely to be beneficial for cerebral oxygenation in the short term.

A review of intensive care nurse staffing practices overseas: what lessons for Australia?

In view of market-driven health-care policies and the move to greater efficiencies within the health-care system, the cost of nursing care is being increasingly scrutinised. Different overseas practices are commonly cited as justification for changing practices within Australia. This study is based on a review of the literature on intensive care nurse staffing requirements in Australasia; specifically, New South Wales, the United States (US) and, to a lesser extent, Europe. It was found that looking to the US for cost-cutting strategies in intensive care units (ICUs) is based on a false premise: that we are comparing like with like. ICUs in the US have a different historical trajectory and culture, service wider constituencies, have technicians and unregistered personnel providing nursing care and do not provide demonstrably better outcomes or significant cost savings. Research indicates that continuous nursing care by trained professionals provides the best outcomes. If costs must be cut, technology, pharmaceuticals and laboratory tests should be targeted. Further, a greater commitment to the development of a 'progressive patient care' model in hospital planning is required, in order to establish or consolidate an intermediate level of nursing care between the ward and the ICU. Programs aiming to improve and continuously monitor patient care, such as adverse event monitoring, the prevention of unplanned extubation and facilitation of early extubation, should be instituted, as these have been shown to not only reduce ICU costs but also improve patient outcomes.

Neonatal abstinence syndrome

A 12 month review of infants admitted with neonatal abstinence syndrome to a neonatal intensive care unit was undertaken. The relationship of maternal drug abuse to symptoms, the effectiveness of pharmacologic agents in controlling symptoms and the length of inpatient stay were investigated. A retrospective review of maternal and infant records was performed. Those infants with a serial Finnegan score greater than 8 were treated. Pharmacologic treatment was oral morphine sulphate (0.2 mg 4-6 hourly), phenobarbitone (3-7 mgs/kg/day), or combination of the above. 43 infants were admitted to the hospital during the year. The average maternal age was 24.6 years, (18-34 years). Drug use volunteered by the mothers was methadone alone in 6 cases, methadone and benzodiazepines in 14, methadone and heroin and benzodiazepines in 7, methadone and heroin in 10, heroin alone in 2, and other multiple drug use including oral morphine sulphate, dothiepin and cannabis in 4. Average gestational age was 40.3 (35-42 weeks). The average birthweight was 2.81 kgs (1.89-3.91 kgs). Time to onset of withdrawal symptoms was 2.8 (1-13) days. The duration of pharmacologic treatment (oral morphine sulphate and/or phenobarbitone) was 21.8 (1-62) days. The total hospital stay for the 43 infants was 1,011 days. This study confirms that polydrug abuse is the commonest type of drug abuse in Dublin. The duration of withdrawal symptoms is loosely related to drug type, but increasing duration of symptoms is noted for infants exposed to benzodiazepines. Our experience would favour the use of morphine sulphate to treat pure opiate withdrawal symptoms. Over the 12-month period, there was an average occupancy of 3 beds per day in the paediatric department.

A comparison of two methods of securing an endotracheal tube

While a variety of methods exist for securing an endotracheal tube (ETT), there has been little research on their safety and efficacy. This study aimed to test the equivalence of two methods in three critical care settings by randomly assigning patients to receive either the knot, which requires scissors or blade to remove the ETT tape, or the bow, which can be removed manually. These methods were evaluated by comparing ETT movement, malposition, dislodgement, inadvertent extubation, reduced skin integrity, the cutting of the pilot tube and nurse satisfaction. The 5-month study was conducted in three critical care settings in a large tertiary hospital. Of the 230 patients enrolled, 222 completed the trial. Results, based on a randomised, active control equivalence design, demonstrated the two methods to be equally effective with regard to ETT movement > 2 cm (knot = 21 per cent, bow = 19 per cent; 95 per cent confidence interval for the [2 per cent] difference-8 to 12.5 per cent). The incidence of ETT-related complications was similar for both methods. No pilot tubes were cut using either method. Nurses found that patient mouth care was easier and patient comfort and skin integrity enhanced with the bow method. On the other hand, nurses perceived the knot-tying method to be more secure and easier to apply. Given the equivalence of the two methods, the bow would seem preferable for reasons of safety and comfort.

The prevalence of chemical substance and alcohol abuse in an obstetric population in Dublin

OBJECTIVE

To determine the prevalence of illicit drug abuse and alcohol use in an obstetric population based in an urban maternity hospital.

SETTING

A collaborative study between the Rotunda Hospital, Dublin and the Irish National Drug Advisory & Treatment Centre.

DESIGN

A prospective study consisting of anonymous, unlinked urine testing of 504 'first visit' antenatal patients and a separate group of 515 patients six weeks after delivery.

METHODS & OUTCOME MEASURES

Toxicological screening using enzyme-linked immunoassay techniques, with all positive samples being reanalysed. Drug histories were taken and samples were tested for alcohol and six of the most commonly abused drugs. The pre- and postnatal prevalence of abuse was matched with demographic data.

RESULTS

The prevalence of chemical substance misuse in the antenatal population was 2.8% and 5.6% in the postnatal population. Substances identified included benzodiazepines, cannabis, amphetamines, opiates and cocaine. Less than 2% of samples tested positive for alcohol. None of the women yielding positive samples had been pre-identified on the basis of history. A significant proportion of the women were in the high risk categories with regard to age and socio-economic status.

CONCLUSION

The prevalence of drug misuse antenatally was nearly 3% and postnatally almost 6%. Substance abusers in pregnancy are more likely to be single, unemployed, and to have had a previous pregnancy.