British Association of Critical Care Nurses position statement on prescribing in critical care

Background: Nurses in the UK are now one group of non-medical staff who can prescribe. This practice is evolving for critical care nursing staff who care for critically ill patients during their stay in hospital through ward and outpatient follow-up after admission to critical care.
Aim: The purposes of this paper were to present existing information regarding prescribing to support nurses in critical care currently prescribing and to inform those who are intending to prescribe.
Methods: To develop the position statement, a search of the literature was conducted using key databases. To ascertain the current level and type of prescribing in critical care, a short questionnaire was sent by email to British Association of Critical Care Nursing members, and the results of this are presented in Appendix A.
Outcomes/Results: Evidence was found in relation to the history, context in critical care, educational requirements and issues of consent related to non-medical prescribing.
Conclusions: The position statement is based upon evidence from the literature, National Health Service policy and the Nursing and Midwifery Council regulations. It takes account of the critical care patient pathway before, during and after an admission to critical care.     

Understanding gastrointestinal perfusion in critical care: so near, and yet so far

An association between abnormal gastrointestinal perfusion and critical illness has been suggested for a number of years. Much of the data to support this idea comes from studies using gastric tonometry. Although an attractive technology, the interpretation of tonometry data is complex. Furthermore, current understanding of the physiology of gastrointestinal perfusion in health and disease is incomplete. This review considers critically the striking clinical data and basic physiological investigations that support a key role for gastrointestinal hypoperfusion in initiating and/or perpetuating critical disease.     

Erythropoietin deficiency: a complication of cisplatin therapy and its treatment with recombinant human erythropoietin.

Cisplatin (CDDP) has been implicated in the development of anemia via several mechanisms of action, including shortening of red cell (RBC) survival and direct toxicity of the drug on RBC bone marrow precursors. Recent studies and case reports suggest an association between CDDP and the development of hyporegenerative anemia as a consequence of relative erythropoietin (EPO) deficiency. To study the effects of CDDP on the relationship between serum EPO and hemoglobin (Hb) concentration, we measured levels of EPO in 12 patients (1-21 years of age) who were treated with cumulative doses of CDDP ranging from 300 to 720 mg/m2 for a variety of pediatric malignancies. Post-CDDP glomerular filtration rates (GFR) varied from 29 to 143 ml/min/1.73 m2 for 11 of the 12 patients studied. At the completion of CDDP therapy, an inverse linear relationship between log(10) serum EPO and Hb was noted among those patients who retained at least 40-50% of their pre-CDDP therapy GFR. One patient with chronic renal failure at the completion of CDDP therapy (GFR 25-35 ml/min/1.73 m2) exhibited a chronic transfusion-dependent, hyporegenerative anemia that was due to persistently low levels of EPO. Institution of recombinant human (r-Hu) EPO therapy resulted in an abrupt cessation of this patient's RBC transfusion dependency. Additional studies are needed to further characterize the effects of CDDP on EPO production and secretion and to determine optimal dosing schedules for r-Hu EPO in pediatric patients who receive CDDP and other myelosuppressive chemotherapy.     

Sequence variation within the neuropeptide Y gene and obesity in Mexican Americans

OBJECTIVE: Recently, we reported evidence for linkage between neuropeptide Y (NPY) and both obesity and several obesity-related quantitative measures in a sample of Mexican Americans from Starr County, Texas. The purpose of this study was to investigate putative variation within the coding and promoter regions of NPY. RESEARCH METHODS AND PROCEDURES: Five young, obese individuals (body mass index [BMI] 33 to 45 kg/m2, age 14 to 30 years); five adult, lean individuals (BMI 20 to 26 kg/m2, age 39 to 65 years); and five sibling pairs sharing no alleles that were identical by descent at a marker locus proximal to NPY were selected for fluorescence-based sequencing of approximately 1100 base pairs (bp) immediately 5' from the start site and all four exons of NPY. We identified a total of eight variant sites, including a 2-bp insertion/deletion (I/D) within a putative negative regulatory region (-880I/D) and a 17-bp deletion at the exon 1/intron 1 junction (69I/D). The -880I/D and 69I/D variants were typed in a separate random sample of Mexican Americans (N = 914) from Starr County, Texas. RESULTS: Analyses of variance resulted in a significant association between -880I/D and waist-to-hip ratio (p = 0.041) in the entire sample and between -880I/D and BMI (p = 0.031), abdominal circumference (p = 0.044), and waist-to-hip ratio (p = 0.041) in a non-obese subsample (BMI < 30 kg/m2, n = 594). The 69I/D variant was observed in only one pedigree and does not appear to segregate with obesity within this pedigree. DISCUSSION: This study reports newly identified common human sequence variation within the regulatory and coding sequence of NPY. Several variants were observed, and of those tested, the -880I/D promoter region variant may influence body fat patterning in non-obese individuals but does not appear to play a major role in the etiology of common forms of obesity in this population.     

Performance and sensitivity of modern home pregnancy tests

We have studied the performance of three currently available home pregnancy tests. The Advance is a test based on monoclonal antibodies in an enzyme immunoassay format that specifically detects hCG in urine. The positive results are determined by the presence of a blue color in a color stick (30 minutes). The Daisy 2 and FACT are tests based on monoclonal antibodies that specifically detect hCG in urine in a hemagglutination inhibition assay; positive results are demonstrated by the deposition of a dot ring at the bottom of the test tube (45 minutes). Thirty-five patients who eventually became pregnant in that cycle collected the first morning urine specimens from day of ovulation (determined by ultrasound) in artificial insemination donor (AID) cycles, or from the date of gamete intrafallopian transfer (GIFT) for 16 consecutive days. In each specimen, the Advance, Daisy 2, and FACT tests were performed; in addition, beta-hCG levels were determined by radioimmunoassay. All the home pregnancy tests studied can detect pregnancy as early as 9 or 10 days post-conception, and they give positive results at the time of the expected onset of menses in 70%, 95%, and 88% of cases for Daisy 2, Advance, and FACT, respectively. The sensitivity of the these home pregnancy tests was determined to be about 200 mIU/mL of urine after correlating their positive or negative results with the concentrations of urinary beta-hCG determined by radioimmunoassay.     

Orogenital sex as a cause of nonfatal air embolism in pregnancy

A case of nonfatal air embolism from orogenital sex in the 30th week of pregnancy is described. Because of a delay in the diagnosis, the patient did not receive hyperbaric oxygen therapy until 39 hours after the incident. Severe neurologic dysfunction persisted despite hyperbaric therapy. The world literature on orogenital sex in pregnancy with resultant air embolism is reviewed. The pathophysiology of air embolism and the rationale for hyperbaric oxygen treatment are presented. It is strongly recommended that survivors of this form of air embolism be transferred to hyperbaric facilities as soon as possible to reduce the long-term neurologic sequelae.     

A 9-mo randomized clinical trial comparing fat-substituted and fat-reduced diets in healthy obese men: the Ole Study

BACKGROUND: Dietary fat has been implicated as a risk factor for cardiovascular disease and obesity. OBJECTIVE: We evaluated the effect on body weight, body fat, lipids, glucose, and insulin of replacing dietary fat with olestra in moderately obese men. DESIGN: Forty-five healthy overweight men were randomly assigned to 1 of 3 diets: control diet (33% fat), fat-reduced diet (25% fat), or fat-substituted diet (one-third of dietary fat replaced by olestra to achieve a diet containing 25% metabolizable fat). Body fat was measured by dual-energy X-ray absorptiometry and visceral and subcutaneous abdominal fat by computed tomography. RESULTS: Thirty-six men completed the 9-mo study. Body weight and body fat in the fat-substituted group declined by a mean (+/- SEM) of 6.27 +/- 1.66 and 5.85 +/- 1.34 kg, respectively, over 9 mo compared with 3.8 +/- 1.34 and 3.45 +/- 1.0 kg in the control group and 1.79 +/- 0.81 and 1.68 +/- 0.75 kg in the fat-reduced diet group. At 9 mo, the mean difference in body fat between the fat-reduced and fat-substituted groups was -4.19 +/- 1.19 kg (95% CI: -6.57, -1.81), that between the control and fat-substituted groups was -2.55 +/- 1.21 kg (-0.13, -4.97), and that between the control and fat-reduced groups was 1.63 +/- 1.18 kg (3.96, -0.70). The men eating the fat-reduced diet asked for almost no extra foods, in contrast with the significantly higher requests (P < 0.05) from both of the other 2 groups. CONCLUSION: Replacement of dietary fat with olestra reduces body weight and total body fat when compared with a 25%-fat diet or a control diet containing 33% fat.     

Prediction of body fat in 12-y-old African American and white children: evaluation of methods

BACKGROUND: The prevalence of obesity is increasing in children. Validation of methods of predicting fatness in African American and white children could help to identify children at high risk. OBJECTIVE: We assessed published methods for determining body fat in 12-y-old male and female white and African American schoolchildren. DESIGN: The body fat of 114 children was measured with the use of dual-energy X-ray absorptiometry, underwater weighing (densitometry), measurement of skinfold thicknesses, isotope dilution (H(2)(18)O), and bioelectrical impedance analysis. Formulas derived from these data and from published reports were compared by using the Bland-Altman approach. RESULTS: Calculation of percentage of body fat by using an equation predicting body fat in kg and dividing by the current weight was the criterion method against which the other methods were compared. Four-compartment models had the smallest variability across the range of body fat, and 2 of these models differed from the criterion method by 1-2%. Six methods (the Pennington 4-compartment model, the Wells et al 4-compartment model, the isotope dilution model, dual-energy X-ray absorptiometry, the Pennington skinfold thickness model, and the Pennington density model) provided specificity > 90%, an estimate of body fat that was within the 95% CI of the criterion method, and a difference from the criterion method that was < +/- 2%. Bioelectrical impedance analysis was the least acceptable method. CONCLUSIONS: A 4-compartment model in which body fat in kg is divided by current body weight and multiplied by 100 provides the best estimate of percentage of body fat. The isotope dilution and body density models provide estimates within 2% of the estimate provided by the 4-compartment model. Other models do less well.