Combined dysfunctions of immune cells predict nosocomial infection in critically ill patients.

BACKGROUND: Nosocomial infection occurs commonly in intensive care units (ICUs). Although critical illness is associated with immune activation, the prevalence of nosocomial infections suggests concomitant immune suppression. This study examined the temporal occurrence of immune dysfunction across three immune cell types, and their relationship with the development of nosocomial infection. METHODS: A prospective observational cohort study was undertaken in a teaching hospital general ICU. Critically ill patients were recruited and underwent serial examination of immune status, namely percentage regulatory T-cells (Tregs), monocyte deactivation (by expression) and neutrophil dysfunction (by CD88 expression). The occurrence of nosocomial infection was determined using pre-defined, objective criteria. RESULTS: Ninety-six patients were recruited, of whom 95 had data available for analysis. Relative to healthy controls, percentage Tregs were elevated 6-10 days after admission, while monocyte HLA-DR and neutrophil CD88 showed broader depression across time points measured. Thirty-three patients (35%) developed nosocomial infection, and patients developing nosocomial infection showed significantly greater immune dysfunction by the measures used. Tregs and neutrophil dysfunction remained significantly predictive of infection in a Cox hazards model correcting for time effects and clinical confounders {hazard ratio (HR) 2.4 [95% confidence interval (CI) 1.1-5.4] and 6.9 (95% CI 1.6-30), respectively, P=0.001}. Cumulative immune dysfunction resulted in a progressive risk of infection, rising from no cases in patients with no dysfunction to 75% of patients with dysfunction of all three cell types (P=0.0004). CONCLUSIONS: Dysfunctions of T-cells, monocytes, and neutrophils predict acquisition of nosocomial infection, and combine additively to stratify risk of nosocomial infection in the critically ill.

Does nausea and vomiting of pregnancy play a role in the association found between maternal caffeine intake and fetal growth restriction?

The aim of this study was to explore the relationships between nausea and vomiting in pregnancy and (a) fetal growth restriction; and (b) maternal caffeine metabolism and fetal growth restriction. A cohort of 2,643 pregnant women, aged 18-45 years, attending two UK maternity units between 8 and 12 weeks gestation, was recruited. A validated tool assessed caffeine intake at different stages of pregnancy and caffeine metabolism was assessed from a caffeine challenge test. Experience of nausea and vomiting of pregnancy was self-reported for each trimester. Adjustment was made for confounders, including salivary cotinine as a biomarker of current smoking status. There were no significant associations between fetal growth restriction and nausea and vomiting in pregnancy, even after adjustment for smoking and alcohol intake. There were no significant differences in the relationship between caffeine intake and fetal growth restriction between those experiencing symptoms of nausea and vomiting and those who did not, for either the first (p = 0.50) or second trimester (p = 0.61) after adjustment for smoking, alcohol intake and caffeine half-life. There were also no significant differences in the relationship between caffeine half-life and fetal growth restriction between those experiencing symptoms of nausea and vomiting and those who did not, for either the first trimester (p = 0.91) or the second trimester (p = 0.45) after adjusting for smoking, alcohol intake and caffeine intake. The results from this study show no evidence that the relationship between maternal caffeine intake and fetal growth restriction is modified by nausea and vomiting in pregnancy.

Rapid sequence induction in the emergency department: induction drug and outcome of patients admitted to the intensive care unit.

OBJECTIVES: Etomidate is used widely for rapid sequence induction (RSI) of anaesthesia in the emergency department (ED) as a result of its relative cardiovascular stability. There is concern over possible adrenal suppression and also that outcomes could be worse than in patients given other induction drugs. This possible association has not been studied in ED patients undergoing RSI. METHODS: 525 consecutive patients who underwent RSI in the ED and were subsequently admitted to an intensive care unit (ICU) were reviewed. The following information was retrieved from the records: induction drug use; incidence of hypotension and vasopressor administration at induction; acute physiology and chronic health evaluation (APACHE) II severity of illness and predicted mortality; and ICU and hospital outcome. The choice of induction drug was not controlled but was at the discretion of the attending clinicians. RESULTS: The numbers of patients given an induction drug were 184 etomidate, 306 thiopental and 35 propofol. Patients given etomidate were older and sicker than those given thiopental or propofol. Mortality appeared greater with etomidate but there was no difference when outcome was related to pre-existing risk. Age, APACHE II score and presenting diagnosis were independent predictors of hospital mortality, but etomidate use was not. CONCLUSION: Induction drug was not related to patient outcome in this cohort of patients. The risks of developing hypotension and receiving a vasopressor at induction were greatest with propofol. Emergency physicians should choose an induction drug based on individual patient circumstances, rather than being solely concerned about adrenal suppression.

Therapeutic hypothermia in comatose patients after out-of-hospital cardiac arrest.

Our intensive care unit has been treating comatose patients, following an out-of-hospital cardiac arrest, with therapeutic hypothermia since 2002. In all, 139 out-of-hospital cardiac arrest patients were admitted in the 4-year period 2002-5. Of these, 27% had a favourable outcome (discharged home or to rehabilitation). Forty-one per cent of patients presenting with ventricular fibrillation (VF) and 7% of non-VF patients had a favourable outcome. No patient with an estimated time from collapse to first attempt at cardiopulmonary resuscitation over 12 min survived to hospital discharge. Twenty-two per cent of patients over 70 years were discharged home, suggesting age was not a barrier to surviving out-of-hospital cardiac arrest. The introduction of a therapeutic hypothermia clinical pathway, at the end of 2003 improved the efficiency of cooling. The percentage of patients cooled to below 34 degrees C within 4 h increased from 15 to 51% and those cooled for more than 12 h increased from 30 to 83%.

Index serum hyaluronic acid independently and accurately predicts mortality in patients with liver disease.

BACKGROUND: Hyaluronic acid is a recognised noninvasive marker of liver fibrosis. However, its prognostic ability has not been extensively studied. AIMS: To investigate the ability of an index serum hyaluronic acid measurement to independently predict transplant-free survival in patients with liver disease of varying aetiology and severity. METHODS: This was a retrospective single-centre cohort study. Serum hyaluronic acid was measured at the discretion of the attending clinicians, in patients attending the liver clinic, to assess disease severity. Patients with a hyaluronic acid measurement between 1995 and 2010 were identified. Patient characteristics at the point of hyaluronic acid measurement were recorded from medical records. Follow-up was from date of index hyaluronic acid measurement to date of death, date of transplant or censor date (July 01, 2015). Primary outcomes were all-cause and liver-related mortality. Kaplan-Meier analysis was used to compare survival in 3 patient groups with hyaluronic acid levels of <100 µg/L, 100-300 µg/L and >300 µg/L. Survival models were constructed using Cox proportional hazard and prediction accuracy was assessed by Harrell's C-statistic. RESULTS: Five hundred and eighty nine patients fulfilled inclusion criteria. Median follow-up was 5.6 years (range 0.1-19.7). Transplant-free survival was significantly different between patients with hyaluronic acid <100 µg/L, 100-300 µg/L and >300 µg/L for liver-related as well as all-cause mortality (P < 0.001). Hyaluronic acid level was an independent predictor of survival (liver-related: HR 1.39, 95% CI 1.20-1.60, P < 0.001; all-cause: HR 1.04, 95% CI 1.02-1.06, P = 0.001). The liver-related prediction accuracy of hyaluronic acid was 0.74 (Standard error 0.03). CONCLUSION: Index hyaluronic acid measurement can accurately and independently predict liver-related and all-cause mortality in patients with liver disease.

The relations between vitamin D2 and D3 in the diet and plasma 25OHD2 and 25OHD3 in elderly women in Great Britain.

Vitamin D2 and D3 intake and plasma 25OHD2 and 25OHD3 were measured in 70 elderly women; 13 living at home and 57 long-stay patients with no access to sunlight. Vitamin D2 intake and plasma 25OHD2 were correlated in the whole group (p less than .005) and vitamin D3 intake and plasma 25OHD3 and total D intake and total 25OHD were significantly correlated (p less than .005) in the patients. In the whole group the plasma 25OHD2 increased by 4.5 nmol/l for every 1 microgram increase in vitamin D2 intake. This was also the increase observed in a longitudinal study of vitamin D2 supplements in 11 patients. Vitamin D intake is a significant determinant of plasma 25OHD and the relation between them suggests that stores of vitamin D can be maintained at 20 nmol/l in the elderly by a daily intake of 4 micrograms of vitamin D, even in the absence of sunlight.

The use of monoclonal antibodies specific for seal immunoglobulins in an enzyme-linked immunosorbent assay to detect canine distemper virus-specific immunoglobulin in seal plasma samples.

A method is described for the measurement of antigen-specific immunoglobulin in seal pup plasmas. Four monoclonal antibodies (H1a, H13a, H24b and H49a) raised against grey seal (Halichoerus grypus) immunoglobulin were used in an ELISA procedure. Levels of canine distemper virus (CDV) specific macroglobulin (IgM like protein) were found to peak approximately 10 days after the first vaccination. Levels of other smaller CDV-specific immunoglobulins (IgG like protein) also increased after vaccination. Using immunoblotting the CDV specific IgG-like protein reacted with a CDV protein, having a molecular weight of approximately 75 kDa.

Identification and partial characterization of common seal (Phoca vitulina) and grey seal (Haliochoerus grypus) interleukin-6-like activities.

Interleukin-6 (IL-6) is a pleiotropic molecule with many important immune modulatory actions. We have investigated the production of biological activity of this cytokine in two species of European seal. IL-6-like activity was detected in supernatants from cultured peripheral blood leucocytes. This IL-6-like activity had an apparent molecular weight of 17-26 kDa, similar to that of human IL-6. IL-6-like activity was also detected in plasma taken from seals with symptoms of systemic infection, but not from apparently healthy seals. Inhibition of this plasma and leucocyte derived activity was accomplished with both rabbit and goat antisera raised against recombinant human IL-6. Further investigation using polymyxin-B showed that this activity was not due to residue LPS present in the supernatants or infected plasmas.

Identification, characterisation, and measurement of immunoglobulin concentrations in grey (Haliocherus grypus) and common (Phoca vitulina) seals.

Concentrations of macroglobulin, total gammaglobulin, and a gammaglobulin subclass were measured in grey and common seals. In pups, immunoglobulin M (IgM) was found to rise rapidly, concentrations reaching adult values by approximately 14 days postpartum. Total IgG concentrations increased more slowly, only approaching 50% of juvenile and adult male values by 30 days after birth. Concentrations of the IgG subclass did not change significantly postpartum. Total IgG concentrations measured in adult female grey seals sampled during lactation were found to be lower than in males and juveniles. This apparent immunosuppression may be associated with pregnancy.

Non-prescribed drug use during methadone treatment by clinic- and community-based patients.

We investigated the efficacy of methadone maintenance treatment in clinic-based (n = 10) and community-based (n = 10) patients by studying the relationships between dose, plasma concentrations of methadone and non-prescribed drug-use using logistic regression. We found that clinic-based patients had significantly reduced odds of having a urine sample test positive for illicit drugs when compared to community-based patients (OR = 0.20; 95% confidence interval 0.10-0.38: p < 0.001). There was no relationship between either methadone dose or plasma methadone concentration and testing positive for non-prescribed drugs (including cocaine, cannabis, amphetamine, ecstasy, benzodiazepines). We looked specifically at the misuse of opiate drugs. Location was again important and clinic-based patients had significantly reduced odds of having a urine sample test positive for opiate drugs (OR = 0.36, 95% confidence interval 0.18-0.71: p approximately 0.004). Opiate drug use in our patients was also significantly related to plasma methadone concentration, increasing noticeably when the drug concentration < 0.48 nmol/L (p approximately 0.04). We found no relationship between methadone dose and odds of having a positive urine drug test in either clinic- or community-based patients.

Population-based pharmacokinetic approach for methadone monitoring of opiate addicts: potential clinical utility.

AIMS: There is evidence that plasma methadone measurements may be of benefit in dosage adjustment during methadone maintenance treatment for opiate dependence. However, to date the kinetics of oral rac-methadone have been poorly characterized. We describe plasma methadone concentration-time data collected from 35 opiate addicts. SUBJECTS: Oral doses of rac-methadone were given to 24 male and 11 female addicts attending a community-based drug treatment centre. MEASUREMENTS: Plasma methadone concentrations were measured by liquid chromatography (HPLC). PROCEDURES: Plasma concentration-time data were collected from patients prescribed oral rac-methadone in order to describe the complex kinetics of the drug incorporating its long elimination half-life. FINDINGS: Auto-induction of methadone metabolism was demonstrated and it was observed that clearance of methadone was significantly lower (p < 0.05) in opiate addicts at the start of treatment (median elimination half-life, 128-hours) than in those who had reached steady-state (median elimination half-life, 48 hours). Our data has provided the basis for a population-based pharmacokinetic (POP-PK) model which is intended for use as a clinical tool in association with plasma measurements in methadone maintenance patients. CONCLUSIONS: Using plasma monitoring in combination with the application of Bayesian forecasting it should be possible to predict trough levels of methadone during daily dosing. The model is able to utilize sparse sampling, and two blood samples are expected to be sufficient to define patient compliance. Random samples during treatment could be used to assess methadone dosing by comparing predicted with observed measurements for each individual. The clinical tool could therefore help to detect incomplete (failure to consume the whole daily dose as prescribed) and poor (due to ingestion of extra illicit methadone) compliance as well as therapeutic failure due to drug-drug interactions. Targeting resources in this way could be a cost-effective tool for supervision of methadone dosing.

Tubular damage in patients with hypokalaemia.

Severe hypokalaemia is occasionally associated with gross changes in renal tubular function. We have looked for lesser degrees of renal tubular damage in unselected patients with hypokalemia by measuring the urine excretion of total protein, albumin, the low molecular mass protein beta 2-microglobulin (B2M) and two enzymes, N-acetyl-glucosaminidase (NAG) and alanine aminopeptidase (AAP). The frequency of abnormal values for these tests separately (compared with matched patients without hypokalaemia) was 39-56%. Many patients had an abnormal value for more than one of the tests, but this was at least partly due to chance association rather than to an underlying common mechanism for the several abnormalities. The frequency of abnormal values was greatest in the patients with the lowest plasma potassium concentrations, but not all of these patients had abnormal values for even one of the tests. Repeated measurements during treatment with potassium supplements showed that the tubular damage resolved in some patients but more slowly than the hypokalemia. These results demonstrate that renal tubular damage is common amongst patients with hypokalaemia and is probably a consequence of the hypokalaemia in most of them. The measurements allow detection of patients whose tissues (at least the kidney) are adversely affected by the hypokalaemia, but the clinical usefulness of this information is yet to be established.

Short term effects of SHD 386L and levonorgestrel on bone and mineral metabolism in the postmenopause: a double-blind randomised placebo-controlled trial.

Forty-five healthy postmenopausal women participated in a study designed to examine the effects on bone and mineral metabolism of SHD 386L, a new hormone replacement therapy (HRT) regime. This oral preparation delivers 2 mg estradiol valerate daily and 75 micrograms of levonorgestrel from days 17-28 inclusive of a 28-day cycle. The study was double-blind, randomized and placebo controlled. Patients who received SHD 386L exhibited significant falls in plasma calcium, ionised calcium, phosphate and total alkaline phosphatase. No alteration, however, was observed in plasma osteocalcin. No significant changes in mineral metabolism were observed in a parallel group receiving levonorgestrel alone. The results indicate that SHD 386L is likely to be protective to the skeleton through inhibition of bone resorption and that such actions are attributable to the estrogen component. The preparation was well tolerated, compliance was satisfactory and serious adverse affects were not seen. The above biochemical evidence for skeletal protection will require to be supplemented by prospective biophysical evidence of the effect of SHD 386L on bone mineral density.

Micro-extraction of commonly abused benzodiazepines for urinary screening by liquid chromatography.

We have developed a micro-extraction procedure for the analysis of seven commonly prescribed benzodiazepines (chlordiazepoxide, diazepam, lorazepam, nitrazepam, nordiazepam, oxazepam, and temazepam) in urine using liquid chromatography. The method is reliable and sensitive, uses small volumes (100 microL) of urine and is suitable for the detection and quantification of low concentrations of benzodiazepines. The micro-extraction procedure allowed rapid sample processing, which is important for routine sample handling. The limit of detection for the seven benzodiazepines ranged from 0.10-0.71 mg/L and recovery of the different benzodiazepines was good, ranging from 70-105%. Between- and within-assay coefficients of variation ranged from 6.3% to 13.8%, and 2% to 3.5%, respectively. Chlordiazepoxide chromatographed poorly (between assay coefficient of variation 35.4%, within-assay 7%), and we set the cut-off value for this compound at 5.0 mg/L.

Micro-extraction of chlordiazepoxide and its primary metabolites, desmethylchlordiazepoxide and demoxepam, from plasma and their measurement by liquid chromatography.

We have developed a micro-extraction procedure for the analysis of chlordiazepoxide and its two unique metabolites, demoxepam and desmethylchlordiazepoxide, in plasma, using liquid chromatography. The method is both reliable and sensitive for the quantitation of low plasma concentrations of these three compounds. The extraction procedure allows rapid sample processing, which, together with the small sample volume (100 microL), makes it ideal for routine sample handling. The limit of detection for the three compounds ranged from 0.075 to 0.125 mg/L and recovery of the three different benzodiazepines ranged from 87 to 94%. Within- and between-assay coefficients of variation ranged from 3.1-4.5% and from 4.7 to 7.6%, respectively.

A rapid horizontal TLC method for detecting drugs of abuse.

We present a rapid, low-cost method for detecting opioids, cocaine and amphetamine in the urine of drug abusers. Rapid solid phase extraction of 2 mL of urine using octadecylsilane cartridges (Bond Elut C18) concentrates compounds of interest (including the polar metabolite of cocaine, benzoylecgonine), in a small volume of methanol, which is easily dried down. Four microlitres of aliquots of samples and standards are spotted on to 5 cm square polyester-backed silica gel plates, and developed (8-10 min) in a Desaga H-Chamber. Rf values of all relevant compounds are presented for two mobile phases using an iodoplatinate spray. The sensitivity of the method is not the same for all drugs but is always at least 1 microgram/mL urine. A number of investigations can be performed on a single extract from 2 mL of urine including confirmatory tests using different solvent systems or sprays.

An evaluation of the measurement of drugs of abuse by commercial and in-house horizontal thin layer chromatography.

We have compared an in-house horizontal thin layer chromatography (TLC) method with a commercial TLC screening kit (Toxi-Lab) to find the most suitable method for screening urine for opioid drugs. The in-house TLC procedure is cheaper and more efficient than the commercial TLC method and is ideal as a confirmatory method when used in conjunction with other established laboratory methods. The in-house TLC method is useful for one-off requests and is able to differentiate between small quantities (0.1-0.5 mg/L) of the different, commonly abused opioids and their metabolites, which means that it is well suited for use at a local Drug Addiction Unit as a routine screening service.

The relationship between theophylline, caffeine and heart rate in neonates.

Plasma theophylline and caffeine levels were measured in neonates receiving aminophylline for apnoea. Significant levels of caffeine were present in neonates with high plasma theophylline levels and particularly in those children who had been on theophylline for 6 days, or more. Caffeine levels in plasma decreased slowly compared to theophylline. Tachycardia did not occur in any infants even at theophylline values greater than 20 mg/L. For theophylline concentrations above 10 mg/L there was no relationship between heart rate and drug level. Heart rate alone cannot be used to predict toxic drug levels, and high drug levels will not necessarily cause tachycardia.

Benzodiazepine misuse by drug addicts.

Using a high-performance liquid chromatography method, we measured seven commonly prescribed benzodiazepines (chlordiazepoxide, nitrazepam, nordiazepam, oxazepam, lorazepam, temazepam and diazepam) in 100 urine samples obtained from patients attending the Leeds Addiction Unit. All of the urines selected for investigation were positive for benzodiazepines using an EMIT (Enzyme Immunoassay) screen. Forty-four of the urines contained a range of benzodiazepines, none of which had been prescribed. Nitrazepam was detected most frequently (61 urine samples), but had not been prescribed to any of the patients in this study. Chlordiazepoxide was detected in 49 urine samples, although it had been prescribed to only five patients. Temazepam was detected in 28 urine samples. Fourteen patients providing 21 urine samples had been prescribed temazepam for treatment. However, temazepam was detected in only 14 of these samples. Multiple benzodiazepine abuse was evident from the high rate of detection of unrelated benzodiazepines.

Essential fatty acid restriction inhibits vitamin D-dependent calcium absorption.

Essential fatty acid (EFA) restriction has been found to inhibit the action of vitamin D on the active transport of calcium in the intestine. This inhibition suggests EFAs are involved in facilitating the active transport of calcium across the mucosal membrane.