Long-term Outcomes with Spinal versus General Anesthesia for Hip Fracture Surgery: A Randomized Trial

BACKGROUND

The effects of spinal versus general anesthesia on long-term outcomes have not been well studied. This study tested the hypothesis that spinal anesthesia is associated with better long-term survival and functional recovery than general anesthesia.

METHODS

A prespecified analysis was conducted of long-term outcomes of a completed randomized superiority trial that compared spinal anesthesia versus general anesthesia for hip fracture repair. Participants included previously ambulatory patients 50 yr of age or older at 46 U.S. and Canadian hospitals. Patients were randomized 1:1 to spinal or general anesthesia, stratified by sex, fracture type, and study site. Outcome assessors and investigators involved in the data analysis were masked to the treatment arm. Outcomes included survival at up to 365 days after randomization (primary); recovery of ambulation among 365-day survivors; and composite endpoints for death or new inability to ambulate and death or new nursing home residence at 365 days. Patients were included in the analysis as randomized.

RESULTS

A total of 1,600 patients were enrolled between February 12, 2016, and February 18, 2021; 795 were assigned to spinal anesthesia, and 805 were assigned to general anesthesia. Among 1,599 patients who underwent surgery, vital status information at or beyond the final study interview (conducted at approximately 365 days after randomization) was available for 1,427 (89.2%). Survival did not differ by treatment arm; at 365 days after randomization, there were 98 deaths in patients assigned to spinal anesthesia versus 92 deaths in patients assigned to general anesthesia (hazard ratio, 1.08; 95% CI, 0.81 to 1.44, P = 0.59). Recovery of ambulation among patients who survived a year did not differ by type of anesthesia (adjusted odds ratio for spinal vs. general, 0.87; 95% CI, 0.67 to 1.14; P = 0.31). Other outcomes did not differ by treatment arm.

CONCLUSIONS

Long-term outcomes were similar with spinal versus general anesthesia.

EDITOR’S PERSPECTIVE

Outcomes with spinal versus general anesthesia for patients with and without preoperative cognitive impairment: Secondary analysis of a randomized clinical trial

INTRODUCTION

The effect of spinal versus general anesthesia on the risk of postoperative delirium or other outcomes for patients with or without cognitive impairment (including dementia) is unknown.

METHODS

Post hoc secondary analysis of a multicenter pragmatic trial comparing spinal versus general anesthesia for adults aged 50 years or older undergoing hip fracture surgery.

RESULTS

Among patients randomized to spinal versus general anesthesia, new or worsened delirium occurred in 100/295 (33.9%) versus 107/283 (37.8%; odds ratio [OR] 0.85; 95% confidence interval [CI] 0.60 to 1.19) among persons with cognitive impairment and 70/432 (16.2%) versus 71/445 (16.0%) among persons without cognitive impairment (OR 1.02; 95% CI 0.71 to 1.47, p = 0.46 for interaction). Delirium severity, in-hospital complications, and 60-day functional recovery did not differ by anesthesia type in patients with or without cognitive impairment.

DISCUSSION

Anesthesia type is not associated with differences in delirium and functional outcomes among persons with or without cognitive impairment.

Pain, Analgesic Use, and Patient Satisfaction With Spinal Versus General Anesthesia for Hip Fracture Surgery : A Randomized Clinical Trial

BACKGROUND

The REGAIN (Regional versus General Anesthesia for Promoting Independence after Hip Fracture) trial found similar ambulation and survival at 60 days with spinal versus general anesthesia for hip fracture surgery. Trial outcomes evaluating pain, prescription analgesic use, and patient satisfaction have not yet been reported.

OBJECTIVE

To compare pain, analgesic use, and satisfaction after hip fracture surgery with spinal versus general anesthesia.

DESIGN

Preplanned secondary analysis of a pragmatic randomized trial. (ClinicalTrials.gov: NCT02507505).

SETTING

46 U.S. and Canadian hospitals.

PARTICIPANTS

Patients aged 50 years or older undergoing hip fracture surgery.

INTERVENTION

Spinal or general anesthesia.

MEASUREMENTS

Pain on postoperative days 1 through 3; 60-, 180-, and 365-day pain and prescription analgesic use; and satisfaction with care.

RESULTS

A total of 1600 patients were enrolled. The average age was 78 years, and 77% were women. A total of 73.5% (1050 of 1428) of patients reported severe pain during the first 24 hours after surgery. Worst pain over the first 24 hours after surgery was greater with spinal anesthesia (rated from 0 [no pain] to 10 [worst pain imaginable]; mean difference, 0.40 [95% CI, 0.12 to 0.68]). Pain did not differ across groups at other time points. Prescription analgesic use at 60 days occurred in 25% (141 of 563) and 18.8% (108 of 574) of patients assigned to spinal and general anesthesia, respectively (relative risk, 1.33 [CI, 1.06 to 1.65]). Satisfaction was similar across groups.

LIMITATION

Missing outcome data and multiple outcomes assessed.

CONCLUSION

Severe pain is common after hip fracture. Spinal anesthesia was associated with more pain in the first 24 hours after surgery and more prescription analgesic use at 60 days compared with general anesthesia.

PRIMARY FUNDING SOURCE

Patient-Centered Outcomes Research Institute.

Spinal Anesthesia or General Anesthesia for Hip Surgery in Older Adults

BACKGROUND

The effects of spinal anesthesia as compared with general anesthesia on the ability to walk in older adults undergoing surgery for hip fracture have not been well studied.

METHODS

We conducted a pragmatic, randomized superiority trial to evaluate spinal anesthesia as compared with general anesthesia in previously ambulatory patients 50 years of age or older who were undergoing surgery for hip fracture at 46 U.S. and Canadian hospitals. Patients were randomly assigned in a 1:1 ratio to receive spinal or general anesthesia. The primary outcome was a composite of death or an inability to walk approximately 10 ft (3 m) independently or with a walker or cane at 60 days after randomization. Secondary outcomes included death within 60 days, delirium, time to discharge, and ambulation at 60 days.

RESULTS

A total of 1600 patients were enrolled; 795 were assigned to receive spinal anesthesia and 805 to receive general anesthesia. The mean age was 78 years, and 67.0% of the patients were women. A total of 666 patients (83.8%) assigned to spinal anesthesia and 769 patients (95.5%) assigned to general anesthesia received their assigned anesthesia. Among patients in the modified intention-to-treat population for whom data were available, the composite primary outcome occurred in 132 of 712 patients (18.5%) in the spinal anesthesia group and 132 of 733 (18.0%) in the general anesthesia group (relative risk, 1.03; 95% confidence interval [CI], 0.84 to 1.27; P = 0.83). An inability to walk independently at 60 days was reported in 104 of 684 patients (15.2%) and 101 of 702 patients (14.4%), respectively (relative risk, 1.06; 95% CI, 0.82 to 1.36), and death within 60 days occurred in 30 of 768 (3.9%) and 32 of 784 (4.1%), respectively (relative risk, 0.97; 95% CI, 0.59 to 1.57). Delirium occurred in 130 of 633 patients (20.5%) in the spinal anesthesia group and in 124 of 629 (19.7%) in the general anesthesia group (relative risk, 1.04; 95% CI, 0.84 to 1.30).

CONCLUSIONS

Spinal anesthesia for hip-fracture surgery in older adults was not superior to general anesthesia with respect to survival and recovery of ambulation at 60 days. The incidence of postoperative delirium was similar with the two types of anesthesia. (Funded by the Patient-Centered Outcomes Research Institute; REGAIN ClinicalTrials.gov number, NCT02507505.).

Intrathecal morphine administration reduces postoperative pain and peripheral endocannabinoid levels in total knee arthroplasty patients: a randomized clinical trial

Background

The primary goal of this study was to determine whether administration of intrathecal morphine reduces postoperative pain. The secondary goal was to determine the effect of intrathecal morphine upon circulating levels of the weakly analgesic endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and the related lipids palmitoylethanolamide (PEA) and oleoylethanolamide (OEA).

Methods

Forty two total knee arthroplasty (TKA) patients were enrolled in a prospective, double-blinded, randomized study. The intervention consisted of intrathecal morphine (200 μg) or placebo administered at the time of the spinal anesthesia. Postoperative pain was measured during the first 4 h after surgery while serum levels of AEA, 2-AG, PEA, OEA, and cortisol were measured at baseline and 4 h after surgery.

Results

Administration of intrathecal morphine reduced postoperative pain 4 h after TKA surgery compared to placebo (p = 0.005) and reduced postoperative systemic opioid consumption (p = 0.001). At baseline, intrathecal morphine led to a significant reduction in AEA, 2-AG, and OEA levels but did not affect PEA or cortisol levels. In patients administered intrathecal placebo, 2-AG levels were elevated 4 h after surgery; whereas patients receiving intrathecal morphine showed reductions in AEA, PEA, and OEA when compared to placebo. At 4 h after TKA surgery cortisol levels were significantly elevated in the placebo group and reduced in those receiving morphine.

Conclusions

These results indicate that intrathecal morphine reduces postoperative pain in TKA patients. Furthermore, activation of central opioid receptors negatively modulates the endocannabinoid tone, suggesting that potent analgesics may reduce the stimulus for production of peripheral endocannabinoids. This study is the first to document the existence of rapid communication between the central opioid and peripheral endocannabinoid systems in humans.

Trial registration

This trial was registered retrospectively. Trial registry: NCT02620631. Study to Examine Pain Relief With Supplemental Intrathecal Morphine in TKA Patients, NCT02620631, 12/03/2015.

Interleukin-6 and leptin levels are associated with preoperative pain severity in patients with osteoarthritis but not with acute pain after total knee arthroplasty

BACKGROUND

Identifying drivers of pain that can serve as novel drug targets is important for improving perioperative analgesia. Total knee arthroplasty (TKA) is associated with significant postoperative pain. Cytokines contribute to the pathophysiology of osteoarthritis (OA) and associated pain. However, the influence of perioperative cytokine levels after TKA surgery upon postoperative pain remains unexplored.

METHODS

We designed a prospective observational study to profile three proinflammatory cytokines, interleukin-6 (IL-6), tumor necrosis factor α (TNFα), and leptin in serum, synovial, and cerebrospinal fluid of TKA patients perioperatively to determine associations between cytokine levels and pain. We characterized time-trajectories in cytokines pre- and post-surgery and explored their relationships to pain across gender.

RESULTS

Preoperative pain, measured by functional pain disability scores (PDQ), was predictive of postoperative pain. There were no gender differences in severity of preoperative pain or acute postoperative pain. Serum IL-6, serum leptin, and synovial fluid leptin were positively correlated with body mass index and preoperative pain severity. Stratification of patients by gender revealed strong correlations between serum IL-6, leptin, and PDQ only in females, suggesting that females may be more sensitive to the nociceptive actions of these cytokines. Although serum IL-6 increased dramatically (and TNFα increased modestly) four hours after surgery and remained elevated at 72h; they were not associated with the severity of acute postoperative pain.

CONCLUSIONS

Our data suggest that while preoperative chronic pain is predictive of the severity of acute postoperative pain in TKA patients, the pre- and post-operative inflammatory status does not predict postoperative pain.

Introducing automated hand hygiene surveillance to an Australian hospital: Mirroring the HOW2 Benchmark Study

BACKGROUND

Human auditing and collating hand hygiene compliance data take hundreds of hours. We report on 24/7 overt observations to establish adjusted average daily hand hygiene opportunities (HHOs) used as the denominator in an automated surveillance that reports daily compliance rates.

METHODS

Overt 24/7 automated surveillance collected HHOs in medical and surgical wards. Accredited auditors observed health care workers' interaction between patient and patient zones to collect the total number of HHOs, indications, and compliance and noncompliance. Automated surveillance captured compliance (ie, events) via low power radio connected to alcohol-based handrub (ABHR) dispensers. Events were divided by HHOs, adjusted for daily patient-to-nurse ratio, to establish daily rates.

RESULTS

Human auditors collected 21,450 HHOs during 24/7 with 1,532 average unadjusted HHOs per day. This was 4.4 times larger than the minimum ward sample required for accreditation. The average adjusted HHOs for ABHR alone on the medical ward was 63 HHOs per patient day and 40 HHOs per patient day on the surgical ward. From July 1, 2014-July 31, 2015 the automated surveillance system collected 889,968 events.

CONCLUSIONS

Automated surveillance collects 4 times the amount of data on each ward per day than a human auditor usually collects for a quarterly compliance report.

An average hand hygiene day for nurses and physicians: The burden is not equal

BACKGROUND

To understand whether the burden of hand hygiene contributes to poor compliance we measured the daily number of hand hygiene opportunities (HHOs) by shift for nurses and physicians in 2 wards in a 850-bed university teaching hospital.

METHODS

On each ward 4 trained auditors collected the number of HHOs and compliance events for 24 hours over 7 days. Twenty-one thousand four hundred fifty HHOs were collected from a medical and a surgical ward. The proportion of alcohol-based handrub used daily, the burden of hand hygiene, and compliance rates were calculated separately for nurses and physicians.

RESULTS

The average indication for alcohol-based handrub cleansing represented 68% of all HHOs. Nurses had an average burden of 55 HHOs per 24 hours or 27 HHOs per shift, 3 times higher than the burden for physicians, who had 16 HHOs per 24 hours or 8 HHOs per shift. Overt observations of the weekly compliance identified nurses had 1.5 times higher compliance than physicians: 76% and 52% (P < .01), respectively.

CONCLUSIONS

Nurses have 3 times more HHOs than physicians, yet nurses have 1.5 times higher compliance than physicians. Hand hygiene compliance in physicians cannot be explained by burden of HHOs.

Knowledge and perception about climate change and human health: findings from a baseline survey among vulnerable communities in Bangladesh

BACKGROUND

Bangladesh is one of the countries most vulnerable to climate change (CC). A basic understanding of public perception on vulnerability, attitude and the risk in relation to CC and health will provide strategic directions for government policy, adaptation strategies and development of community-based guidelines. The objective of this study was to collect community-based data on peoples' knowledge and perception about CC and its impact on health.

METHODS

In 2012, a cross-sectional survey was undertaken among 6720 households of 224 enumeration areas of rural villages geographically distributed in seven vulnerable districts of Bangladesh, with total population of 19,228,598. Thirty households were selected randomly from each enumeration area using the household listing provided by the Bangladesh Bureau of Statistics (BBS). Information was collected from all the 6720 research participants using a structured questionnaire. An observation checklist was used by the interviewers to collect household- and community-related information. In addition, we selected the head of each household as the eligible participant for an interview. Evidence of association between sociodemographic variables and knowledge of CC was explored by cross-tabulation and measured using chi-square tests. Logistic regression models were used to further explore the predictors of knowledge.

RESULTS

The study revealed that the residents of the rural communities selected for this study largely come from a low socioeconomic background: only 9.6% had postsecondary education or higher, the majority worked as day labourer or farmer (60%), and only 10% earned a monthly income above BDT 12000 (equivalent to US $150 approx.). The majority of the participants (54.2%) had some knowledge about CC but 45.8% did not (p < 0.001). The majority of knowledgeable participants (n = 3645) felt excessive temperature as the change of climate (83.2%). Among all the respondents (n = 6720), 94.5% perceived change in climate and extreme weather events. Most of them (91.9%) observed change in rainfall patterns in the last 10 years, and 97.8% people think their health care expenditure increased after the extreme weather events. Age, educational qualification, monthly income, and occupation were significantly associated with the knowledge about climate change (p < 0.001). People with higher educational level or who live near a school were more knowledgeable about CC and its impact on health.

CONCLUSIONS

The knowledge level about CC in our study group was average but the perception and awareness of CC related events and its impact on health was high. The most influential factor leading to understanding of CC and its impact on health was education. School-based intervention could be explored to increase peoples' knowledge about CC and necessary health adaptation at community level.

Meticillin-resistant Staphylococcus aureus (MRSA) antibiogram: How inaccurate have our estimates been?

The objective of this study was to determine the accuracy of antimicrobial resistance patterns reported by the Australian Group on Antimicrobial Resistance (AGAR) established using surveys of just the first 100 Staphylococcus aureus isolates from each participating hospital. Patterns of resistance of a survey sample of S. aureus isolates collected prospectively from five Queensland hospitals participating in the AGAR biennial national survey, using the first 100 isolates diagnosed from each test year, were tested. Meticillin-resistant S. aureus (MRSA) antibiograms for five antimicrobials commonly used to treat outpatients established from a sample have underestimated the true level of resistance by 13-21 percentage points. Conversely, inpatient antibiograms have significantly overestimated the resistance level. Random selection of 100 isolates from all isolates did not provide valid resistance patterns for outpatients or inpatients. Nearly 50% of resistance demonstrated in all inpatient isolates and about 45% of resistance in all outpatient isolates was due to AUS-2/3-like, EMRSA-15-like and MRSA unclassified. In conclusion, testing S. aureus, and in particular MRSA, for resistance levels to commonly prescribed antimicrobials is under/over-estimated in Australia because of a faulty annual sampling method that failed to consider the effect of endemic phenotypes (AUS-2/3-like and EMRSA-15-like). MRSA represents one-third of all S. aureus AGAR isolates. Endemic phenotypes bias the antibiogram patterns when small consecutive sampling (first 100 samples) is used and this bias remains even when samples are selected at random. A minimum sample of 6 months of isolates must be used to accurately establish a national antibiogram.

Leptin levels are negatively correlated with 2-arachidonoylglycerol in the cerebrospinal fluid of patients with osteoarthritis

BACKGROUND

There is compelling evidence in humans that peripheral endocannabinoid signaling is disrupted in obesity. However, little is known about the corresponding central signaling. Here, we have investigated the relationship between gender, leptin, body mass index (BMI) and levels of the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in the serum and cerebrospinal fluid (CSF) of primarily overweight to obese patients with osteoarthritis.

METHODOLOGY/PRINCIPAL FINDINGS

Patients (20 females, 15 males, age range 44-78 years, BMI range 24-42) undergoing total knee arthroplasty for end-stage osteoarthritis were recruited for the study. Endocannabinoids were quantified by liquid chromatography - mass spectrometry. AEA and 2-AG levels in the serum and CSF did not correlate with either age or BMI. However, 2-AG levels in the CSF, but not serum, correlated negatively with CSF leptin levels (Spearman's ρ -0.48, P=0.0076, n=30). No such correlations were observed for AEA and leptin.

CONCLUSIONS/SIGNIFICANCE

In the patient sample investigated, there is a negative association between 2-AG and leptin levels in the CSF. This is consistent with pre-clinical studies in animals, demonstrating that leptin controls the levels of hypothalamic endocannabinoids that regulate feeding behavior.

Doctor, do you have a moment? National Hand Hygiene Initiative compliance in Australian hospitals

OBJECTIVES

To examine hand hygiene compliance rates for medical and nursing staff, compliance with hand hygiene before touching a patient (Moment 1 of the Five moments for hand hygiene), and the effect of differential sampling of staff on the average national rate. Also, to establish whether hand hygiene rates impact Staphylococcus aureus bloodstream infections (SABSI).

DESIGN AND SETTING

Analysis of data from three different cross-sectional datasets--Hand Hygiene Australia data for 246,665 hand hygiene opportunities during the first quarter (1 January to 31 March) of 2013 from 82 public hospitals representing eight Australian states and territories, and hand hygiene rates and SABSI rates from the MyHospitals website reported for 1 July 2011 to 30 June 2012.

MAIN OUTCOME MEASURES

Compliance by medical and nursing staff for each hospital size (> 400 beds, 301-400 beds, 201-300 beds, and 101-200 beds); the proportion of hospitals with hand hygiene compliance rates for before touching a patient at or above, or below the national threshold of 70%; the impact of hand hygiene on SABSI.

RESULTS

Medical staff consistently performed below the national threshold for hand hygiene compliance regardless of hospital size. Nurses' compliance was consistently above the threshold, and this inflated the total average national rate. A third of the patient interaction hand hygiene opportunities recorded involved before touching a patient, for which compliance was below the national threshold in 68% of hospitals. Hand hygiene has little impact on the rate of SABSI (incidence rate ratio, 0.97; P < 0.01).

CONCLUSIONS

Posting a national unadjusted average hand hygiene compliance rate on a public website conceals the fact that most hospitals and medical staff are performing below the national hand hygiene compliance threshold. Given the poor compliance after 4 years of auditing to capture non-compliance, we must shift our focus to providing medical staff with immediate feedback and move to improving a single hand hygiene indication at a time, starting with before touching a patient.

Trends in Sri Lankan cause-specific adult mortality 1950-2006

BACKGROUND

Although all-cause mortality in Sri Lanka decreased significantly from 1950 to 1970, subsequent declines have been more modest with divergent trends by age and sex. This study investigates these trends through cause of death analysis for 1950-2006 in adults aged 15-64 years.

METHODS

Deaths were obtained from the World Health Organisation (WHO) mortality database for 1950 to 2003, and the Department of Census and Statistics Sri Lanka for 1992-95 and 2004-06 where WHO data was unavailable. Adult deaths were categorised by age (15-34 and 35-64 years) and sex into: infectious diseases; external-causes; circulatory diseases; cancers; digestive diseases; respiratory diseases; pregnancy-related; ill-defined; and other-causes. Cause-specific mortality rates were directly age-standardised to the 2001 Sri Lankan Census population.

RESULTS

Mortality declined in females aged 15-34 years by 85% over 1950-2006, predominantly due to sharp declines in infectious disease and pregnancy-related mortality over 1950-70. Among males aged 15-34 years the mortality decline was less at 47%, due to a rise in external-cause mortality during 1970-2000. In females aged 35-64 years mortality declined by 67% over 1950-2006, predominantly due to a sharp decline in infectious disease, ill-defined and other cause mortality over 1950-70. Among males aged 35-64 years, decline in mortality is evident to 1960 (19%) from decline in infectious disease mortality, followed by increased mortality from circulatory diseases and external cause mortality, despite continued decline in infectious disease mortality. All-cause mortality in males 35-64 years has stagnated since 1970, with fluctuating increases. Circulatory diseases were the leading cause of death among adults 35-64 years in 2002-06, with the male rate almost three times higher than females.

CONCLUSIONS

Significant disparities are demonstrated in Sri Lankan cause-specific adult mortality by sex and age group for 1950-2006. Female mortality progressively declined while male mortality demonstrated periods of increase and stagnation. Among males aged 15-34 years this coincides with periods of civil conflict over 1970-2000. Among males aged 35-64 years the increased mortality from non-communicable disease and external causes are the main reasons for stagnation in all-cause mortality since the 1970's.

Association between hypertension and chronic arsenic exposure in drinking water: a cross-sectional study in Bangladesh

Chronic arsenic exposure and its association with hypertension in adults are inconclusive and this cross-sectional study investigated the association. The study was conducted between January and July 2009 among 1,004 participants from 1,682 eligible women and men aged ≥30 years living in rural Bangladesh who had continuously consumed arsenic-contaminated drinking water for at least 6 months. Hypertension was defined as systolic blood pressure ≥140 mmHg (systolic hypertension) and diastolic blood pressure ≥90 mmHg (diastolic hypertension). Pulse pressure was calculated by deducting diastolic from systolic pressure and considered to be increased when the difference was ≥55 mmHg. The prevalence of hypertension was 6.6% (95% CI: 5.1-8.3%). After adjustment for other factors, no excess risk of hypertension was observed for arsenic exposure >50 μg/L or to that of arsenic exposure as quartiles or as duration. Arsenic concentration as quartiles and >50 μg/L did show a strong relationship with increased pulse pressure (adjusted OR: 3.54, 95% CI: 1.46-8.57), as did arsenic exposure for ≥10 years (adjusted OR: 5.25, 95% CI: 1.41-19.51). Arsenic as quartiles showed a dose response relationship with increased pulse pressure. Our study suggests an association between higher drinking water arsenic or duration and pulse pressure, but not hypertension.

Abstract 149: Association Between Hypertension and Chronic Exposure in Bangladesh

Objective: To determine the association between chronic arsenic exposure via drinking water and prevalence of hypertension among rural Bangladeshi adults.

Design, Setting, Participants: This is an analytical cross sectional study among 1004 participants from 1682 eligible men and women (Participation rate 60%) aged >30 years living in Bangladesh who had continuously consumed arsenic-contaminated drinking water for at least 6 months.

Main Outcome Measures: Hypertension was defined as systolic blood pressure > 140 mm of Hg or a diastolic blood pressure > 90 mm of Hg or in combination of the both.

Results: A total of 1004 individuals participated in the study. The prevalence of hypertension was 6.6% (95% CI 5.1-8.3%). After adjustment for participant’s age, sex, education, religion, marital status, sign of arsenical skin lesions, monthly household income and BMI, no excess risk of hypertension was observed for drinking water arsenic exposure over 50μg/L. Also, there was no increased risk for higher concentration of arsenic in the drinking water. Arsenic concentration >50 μg/L in drinking water showed no association with systolic, diastolic hypertension separately however, it shows a strong relationship with increased pulse pressure when pulse pressure categorized as <55 and ≥55 mmHg (Adjusted OR: 3.06, CI: 1.22-7.65). Also, duration of exposure to arsenic didn’t show any impact on an increased risk to hypertension except pulse pressure when exposed to arsenic for ≥10 years (Adjusted OR: 4.74, CI: 1.25-17.88).

Conclusion: Unlike other studies conducted in developing countries that reported a significant association, this study suggests no association between higher drinking water arsenic concentration and hypertension except for pulse pressure.

Comparison of the sensory irritation response in mice to chlorine and nitrogen trichloride

The expiratory bradypnoea indicative of upper airway irritation in mice was evaluated during a 60-min oronasal exposure to increasing concentrations of chlorine and nitrogen trichloride. The airborne concentration resulting in a 50% decrease in the respiratory rate of mice (RD50) was calculated for each chemical. Chlorine and nitrogen trichloride showed dissimilar concentration-response curves. While the maximal response of nitrogen trichloride was reached in 10 min, the maximal response of chlorine was reached between 45 and 60 min of exposure. The results showed both chemicals to have an irritant potency of the same order of magnitude. The RD50 values of chlorine and nitrogen trichloride were 3.5 and 2.5 ppm, respectively. On the basis of a TLV-STEL (threshold limit value for short-term exposure limit) equal to 0.1 RD50 and a TLV-TWA (time-weighted average) equal to 0.03 RD50, the current TLVs for chlorine seem too high (1 and 0.5 ppm, respectively) and should be reduced to 0.5 and 0.1 ppm, respectively. For nitrogen trichloride, 0.3 ppm and 0.1 ppm are proposed as TLV-STEL and TLV-TWA, respectively.

Characterization of mianserin neuroprotection in experimental spinal trauma: dose/route response and late treatment

The neuroprotective action of the 5-hydroxytryptamine (5-HT2/5-HT1C) antagonist mianserin was examined with respect to optimal dosage, route of administration and time of treatment after a moderate spinal impact trauma (50 g.cm by the weight-drop method) to the thoracic region of the rat. In a previous study (Salzman et al., 1991b) a single 1-mg/kg i.v. dose of mianserin improved multiple measures of functional outcome when given 15 min after injury, whereas higher doses (5 and 10 mg/kg i.v.) displayed lesser therapeutic actions as well as pulmonary depressant effects. In these studies, lower dosages of minanserin (0.5 and 0.1 mg/kg i.v.) also were not associated with neuroprotection. Although the 1-mg/kg i.v. dosage again displayed significant efficacy when administered at 15 min delaying treatment to 30 min resulted in only marginal therapeutic actions. Nonetheless, i.p. dosage of 10 mg/kg (but not 2.5 mg/kg) at 15 min retained therapeutic efficacy, suggesting a pharmacodynamic influence. In support of this conclusion, the intrathecal administration of a 50-fold lower dose of minanserin (0.006 mg) at 15 min after injury resulted in neuroprotection that was superior to that of peripheral doses and was retained when this intrathecal dosage was administered at 1 hr after trauma. These results suggest a central mechanism of action for mianserin. Consistent with this was the lack of effect of mianserin (1 mg/kg i.v. at 15 min) upon post-traumatic spinal edema but its ability to reverse the decrease in central 5-HT oxidative metabolism after injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Sensory and pulmonary irritation of aliphatic amines in mice: a structure-activity relationship study

The expiratory bradypnea indicative of upper airway irritation in mice was evaluated during a 15-min oronasal exposure to increasing concentrations of sixteen aliphatic amines. The airborne concentration resulting in a 50% decrease in the respiratory rate of mice (RD50) was calculated for each test compound. Moreover, the sixteen amines were tested for pulmonary irritation by measuring the decrease in respiratory rate of (non-anaesthetized) tracheally cannulated mice (RD50 TC). The RD50 and RD50 TC values and their ratios were related to n-octanol/water partition coefficients (log P). The RD50 values associated with exposure to saturated amines ranged from 17 to 300 ppm. The RD50TC values for these saturated amines ranged from 35 to 489 ppm. The RD50 and RD50TC values of saturated amines were closely related to the n-octanol/water partition coefficient, indicating that the more lipophilic amines are more irritant for the upper and lower respiratory tracts. The RD50TC/RD50 values were much less closely related to the n-octanol/water partition coefficient. Based on the results, tentative standards are suggested for the studied amines.

Smooth muscle guanine nucleotides and receptor-effector coupling following inhibition of oxidative energy production

We measured total concentrations of guanosine triphosphate (GTP) and guanosine diphosphate (GDP) in rabbit aortic smooth muscle under several different conditions. We computed free [GDP] and free GTP/GDP (using a Keq of 1.0 for the nucleoside diphosphate kinase reduction) under these conditions. At a time when muscle was contracted by 15 microM norepinephrine (NE) for 5 min under normoxia, [GTP], free [GDP], and free GTP/GDP were 0.29 +/- 0.03 mM, 3.5 microM, and 82, respectively. Following rapid inhibition of oxidative energy production during NE-evoked maintained force, which is associated with slow decreases in mean tissue [PCr], and [ATP] and force relaxation, [GTP] and free GTP/GDP were decreased at relaxation threshold to 0.22 +/- 0.02 (SE) mM and 43, respectively, and progressively fell further, paralleling decreases in force and [ATP] and [PCr]. There were marked decreases in the sum of GTP + GDP contents under conditions where muscle energy stores were decreased (i.e., low [PCr] + [ATP]). Similar data were obtained during a 50 mM KCl-evoked contracture. Free [GDP] increased from normoxic values of 3.5 microM to values as great as 6.0 microM at low energy store states. Free GDP was equivalent to 6% of total GDP under normoxia and increased to 16-21% of total GDP under conditions of low energy stores. Evidence was obtained that decreases in [GTP] or free GTP/GDP seen under conditions of low total energy stores were not sufficient to inhibit heterotrimeric G protein function and uncouple receptor-effector coupling.

Mothers' fear of child death due to acute diarrhoea: a study in urban and rural communities in northern Punjab, Pakistan

The investigation of cultural models of diarrhoeal illness which are employed by mothers and their emotional responses to children's illnesses is presented in a study of 595 households in urban and rural communities in Punjab, Pakistan. The household survey of mothers of children 0-36 months was complemented with in-depth interviews of a subsample of 70 mothers. Findings indicate that diarrhoea must be regarded not only as a disease but as a symptom belonging to several popular illness categories. Mothers' emotional responses to symptoms are in part shaped by the illness categories to which they assign a child's diarrhoea episode, and maternal fears that symptoms of diarrhoea may be life threatening are associated with previous experiences with death of children, with treatment choices and help-seeking. A significantly higher proportion of mothers who fear diarrhoea to be life threatening to their children than mothers with other concerns choose to use NIMKOL, the Pakistan ORS. The necessity of recognizing the complexity of interpretive and emotional processes which shape the care of children and the home treatment of childhood disease is emphasized.

Inositol 1,4,5-trisphosphate compartmentalization in tracheal smooth muscle

Pool sizes of inositol phosphate species in myo-[3H]inositol-labeled porcine tracheal smooth muscle were determined under three conditions: (a) unstimulated; (b) stimulated with carbachol; (c) atropine-relaxed from a carbachol contraction. In unstimulated muscle, the inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) content was 14 pmol/100 nmol lipid P1. This is equivalent to a mean [Ins(1,4,5)P3] of about 3 microM (in total cellular water), a level about 30-fold in excess of that required for Ca2+ release from Ins(1,4,5)P3-sensitive sarcoplasmic reticulum (SR). Pool sizes of breakdown products of Ins(1,4,5)P3 were relatively small or absent in unstimulated muscle, suggesting that, under this condition, Ins(1,4,5)P3 was sequestered and had limited access to Ins(1,4,5)P3 5-phosphatase and/or 3-kinase. During carbachol stimulation, the Ins(1,4,5)P3 pool did not increase while those of other mono-, di-, and trisphosphate isomers increased over 10-fold. Subsequent atropine-induced relaxation resulted in a partial depletion (40%) of total tissue Ins(1,4,5)P3. Decreases in Ins(1,4,5)P3 were paralleled by decreases in Ins(1,4)P2 and Ins(1,3,4)P3. During contraction a portion of total tissue Ins(1,4,5)P3 has access to Ins(1,4,5)P3 3-kinase and 5-phosphatase and to Ins(1,4,5)P3-sensitive SR, though during antagonist-induced relaxation access to Ins(1,4,5)P3-sensitive SR for Ca2+ release is restricted. Data are consistent with a mechanism by which a large pool of Ins(1,4,5)P3 present in the unstimulated state in a sequestered compartment can contribute in activated muscle to increases in [Ins(1,4,5)P3] in a nonsequestered compartment, controlling SR Ca2+ release.

Feeding practices for young Pakistani children: usual diet and diet during diarrhoea

Diarrhoea is among the foremost disorders responsible for high mortality and morbidity in children of third world countries. In addition, improper feeding during diarrhoea leads to a vicious cycle of frequent episodes of diarrhoea and malnutrition in these children. In this study 595 households (200 urban and 395 rural) with 741 children who met the age criteria of 36 months or less were randomly selected for assessing the feeding practices during diarrhoea. Out of these, 276 (37%) were infants and 465 (63%) were toddlers. The majority of both breastfed and non breastfed children were also receiving solids and liquid foods. Animal milk was used by 89% of non-breastfed children. Forty six percent of breastfed and 78% of non-breastfed children were given "Khitchri" (rice cooked with lentils) as a solid diet. During diarrhoeal episodes, most mothers (70%) continued breast feeding their children. Whereas, 53% children also received solid and semi-solid diet which was either "Khitchri" or banana as mentioned by more than half of the respondents. The majority of mothers (97%) considered breast-feeding to be a good practice during childhood diarrhoea.

The use of ORS (Nimkol) in management of childhood diarrhoea by mothers in the suburbs of Rawalpindi-Islamabad

A total of 595 respondents (200 from urban Kachi-abadis and 395 from rural communities of Rawalpindi-Islamabad) were interviewed for their knowledge about the use of ORS (Nimkol) in childhood diarrhoea. Most of the respondents were mothers with low literacy rate (23%). The prevalence of current diarrhoea among children was 36.8% on the day of interview whereas 57% of the children had history of having suffered from an episode of diarrhoea during the past two weeks. About 75% respondents claimed that they had an experience of using ORS (Nimkol). Most of them (72.1%) had used ORS (Nimkol) for childhood diarrhoea and dehydration and 28% had used it for diseases other than childhood diarrhoea or on doctor's advice. Only 11% mothers of children who were currently suffering from diarrhoea were using ORS (Nimkol) and a few mothers mentioned of giving home made fluid remedies like salt-water, salt-sugar-water or lemon-sugar-salt water for childhood diarrhoea. The use of ORS (Nimkol) was more common among the families with higher income. Regarding the preparation of ORS (Nimkol) solution, 57.8% respondents had fairly accurate knowledge. Fifty percent of the respondents had procured ORS (Nimkol) from the hospitals or clinics.

Nasal irritation and pulmonary toxicity of aliphatic amines in mice

The expiratory bradypnoea indicative of upper airway irritation in mice was evaluated during a 15-min oronasal exposure to increasing concentrations of twenty aliphatic amines. The airborne concentration resulting in a 50% decrease in the respiratory rate of mice (RD50) was calculated for each test compound. Moreover, eight out of the twenty amines were tested for pulmonary toxicity in mice and for the effects of a 120-min exposure on the respiratory rates of non-anaesthetized, tracheally cannulated mice (RD50TC). Both allylamine and diallylamine showed RD50 values of 9 ppm and 4 ppm, respectively, while the RD50 values associated with exposure to saturated amines ranged from 50 to 200 ppm. Among the eight amines tested for both upper airway irritation and pulmonary toxicity, diisopropylamine and di-n-butylamine showed a RD50TC/RD50 ratio of less than 1, indicating that the respiratory toxicity induced by these two amines would be related primarily to pulmonary effects. On the basis of prior predictions proposed for upper airway irritants, tentative standards are given for ten amines. Moreover, it is suggested that the basis of standards for industrial exposure to diisopropylamine and di-n-butylamine should be specified.