Vancomycin use for haemodialysis patients-Development of a new dosing protocol

AIM

To develop a dosing and monitoring protocol to achieve therapeutic vancomycin levels on intermittent haemodialysis.

METHODS

We identified 15 vancomycin treatment courses received by patients on intermittent haemodialysis at a district health board in Auckland, New Zealand. Demographic, biochemical and clinical parameters were gathered from their health records. We subsequently devised and implemented a new vancomycin protocol consisting of weight-based loading dose, and subsequent dose titration according to same-day measured pre-dialysis levels. We then re-audited 16 vancomycin treatment courses to assess the performance of the protocol.

RESULTS

A significantly higher proportion of vancomycin levels were within the target range (15-20 mg/L) following the implementation of protocol, from 23% to 46% (p < .005). Additionally, a greater proportion of treatment courses had >50% of pre-dialysis levels within the target range, rising from 13% to 56% (p < .01). In the pre-protocol group, 19 out of 117 doses of vancomycin were withheld during treatment, compared to 1 out of 118 doses in the post-protocol group. A total of 62% of total maintenance doses were administered in adherence to protocol. Length of hospital stay and number of positive blood cultures while on treatment were reduced.

CONCLUSIONS

Our initial audit revealed deficiencies in our clinical practice in the absence of a local vancomycin protocol for patients receiving intermittent haemodialysis. Following the implementation of our novel protocol, there was an improvement in therapeutic levels and fewer doses were withheld. Our sample size was too small to allow for interpretation of clinical outcome data.

Lack of seroresponse to SARS-CoV-2 booster vaccines given early post-transplant in patients primed pre-transplantation

SARS-CoV-2 vaccines are recommended pre-transplantation, however, waning immunity and evolving variants mandate booster doses. Currently there no data to inform the optimal timing of booster doses post-transplant, in patients primed pre-transplant. We investigated serial serological samples in 204 transplant recipients who received 2 or 3 SARS-CoV-2 vaccines pre-transplant. Spike protein antibody concentrations, [anti-S], were measured on the day of transplantation and following booster doses post-transplant. In infection-naïve patients, post-booster [anti-S] did not change when V3 (1^st booster) was given at 116(78-150) days post-transplant, falling from 122(32-574) to 111(34-682) BAU/ml, p=0.78. Similarly, in infection-experienced patients, [anti-S] on Day-0 and post-V3 were 1090(133-3667) and 2207(650-5618) BAU/ml respectively, p=0.26. In patients remaining infection-naïve, [anti-S] increased post-V4 (as 2^nd booster) when given at 226(208-295) days post-transplant, rising from 97(34-1074) to 5134(229-5680) BAU/ml, p=0.0016. Whilst in patients who had 3 vaccines pre-transplant, who received V4 (as 1^st booster) at 82(49-101) days post-transplant, [anti-S] did not change, falling from 981(396-2666) to 871(242-2092) BAU/ml, p=0.62. Overall, infection pre-transplant and [anti-S] at the time of transplantation predicted post-transplant infection risk. As [Anti-S] fail to respond to SARS-CoV-2 booster vaccines given early post-transplant, passive immunity may be beneficial to protect patients during this period.

Immune responses following 3rd and 4th doses of heterologous and homologous COVID-19 vaccines in kidney transplant recipients

BACKGROUND

Solid organ transplant recipients have attenuated immune responses to SARS-CoV-2 vaccines. In this study, we report on immune responses to 3rd- (V3) and 4th- (V4) doses of heterologous and homologous vaccines in a kidney transplant population.

METHODS

We undertook a single centre cohort study of 724 kidney transplant recipients prospectively screened for serological responses following 3 primary doses of a SARS-CoV2 vaccine. 322 patients were sampled post-V4 for anti-spike (anti-S), with 69 undergoing assessment of SARS-CoV-2 T-cell responses. All vaccine doses were received post-transplant, only mRNA vaccines were used for V3 and V4 dosing. All participants had serological testing performed post-V2 and at least once prior to their first dose of vaccine.

FINDINGS

586/724 (80.9%) patients were infection-naïve post-V3; 141/2586 (24.1%) remained seronegative at 31 (21-51) days post-V3. Timing of vaccination in relation to transplantation, OR: 0.28 (0.15-0.54), p=0.0001; immunosuppression burden, OR: 0.22 (0.13-0.37), p<0.0001, and a diagnosis of diabetes, OR: 0.49 (0.32-0.75), p=0.001, remained independent risk factors for non-seroconversion. Seropositive patients post-V3 had greater anti-S if primed with BNT162b2 compared with ChAdOx1, p=0.001.Post-V4, 45/239 (18.8%) infection-naïve patients remained seronegative. De novo seroconversion post-V4 occurred in 15/60 (25.0%) patients. There was no difference in anti-S post-V4 by vaccine combination, p=0.50. T-cell responses were poor, with only 11/54 (20.4%) infection-naive patients having detectable T-cell responses post-V4, with no difference seen by vaccine type.

INTERPRETATION

A significant proportion of transplant recipients remain seronegative following 3- and 4- doses of SARS-CoV-2 vaccines, with poor T-cell responses, and are likely to have inadequate protection against infection. As such alternative strategies are required to provide protection to this vulnerable group.

FUNDING

MW/PK received study support from Oxford Immunotec.

Comparison of immunogenicity and clinical effectiveness between BNT162b2 and ChAdOx1 SARS-CoV-2 vaccines in people with end-stage kidney disease receiving haemodialysis: A prospective, observational cohort study

Background

People with end-stage kidney disease, including people on haemodialysis, are susceptible to greater COVID-19 related morbidity and mortality. This study compares the immunogenicity and clinical effectiveness of BNT162B2 versus ChAdOx1 in haemodialysis patients.

Methods

In this observational cohort study, 1021 patients were followed-up from time of vaccination until December 2021. All patients underwent weekly RT-PCR screening. Patients were assessed for nucleocapsid(anti-NP) and spike(anti-S) antibodies at timepoints after second(V2) and third(V3) vaccinations. 191 patients were investigated for T-cell responses. Vaccine effectiveness (VE) for prevention of infection, hospitalisation and mortality was evaluated using the formula VE=(1-adjustedHR)x100.

Findings

45.7% (467/1021) had evidence of prior infection. There was no difference in the proportion of infection-naïve patients who seroconverted by vaccine type, but median anti-S antibody titres were higher post-BNT162b2 compared with ChAdOx1; 462(152-1171) and 78(20-213) BAU/ml respectively, p<0.001.  Concomitant immunosuppressant use was a risk factor for non-response, OR 0.12[95% CI 0.05-0.25] p<0.001.  Post-V3 (all BNT162b2), median anti-S antibody titres remained higher in those receiving BNT162b2 versus ChAdOx1 as primary doses; 2756(187-1246) and 1250(439-2635) BAU/ml respectively, p=0.003.Anti-S antibodies waned over time. Hierarchical levels of anti-S post-V2 predicted risk of infection; patients with no/low anti-S being at highest risk. VE for preventing infection, hospitalisation and death was 53% (95% CI 6-75), 77% (95% CI 30-92) and 93% (95% CI 59-99) respectively, with no difference seen by vaccine type.

Interpretation

Serum anti-S concentrations predict risk of breakthrough infection. Anti-S responses vary dependent upon clinical features, infection history and vaccine type. Monitoring of serological responses may enable individualised approaches to vaccine boosters in at risk populations.

Funding

National Institute for Health Research (NIHR) Biomedical Research Centre based at Imperial College Healthcare NHS Trust and Imperial College London.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody lateral flow assay for antibody prevalence studies following vaccination: a diagnostic accuracy study

Background: Lateral flow immunoassays (LFIAs) are able to achieve affordable, large scale antibody testing and provide rapid results without the support of central laboratories. As part of the development of the REACT programme extensive evaluation of LFIA performance was undertaken with individuals following natural infection. Here we assess the performance of the selected LFIA to detect antibody responses in individuals who have received at least one dose of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. Methods: This was a prospective diagnostic accuracy study. Sampling was carried out at renal outpatient clinic and healthcare worker testing sites at Imperial College London NHS Trust. Two cohorts of patients were recruited; the first was a cohort of 108 renal transplant patients attending clinic following two doses of SARS-CoV-2 vaccine, the second cohort comprised 40 healthcare workers attending for first SARS-CoV-2 vaccination and subsequent follow up. During the participants visit, finger-prick blood samples were analysed on LFIA device, while paired venous sampling was sent for serological assessment of antibodies to the spike protein (anti-S) antibodies. Anti-S IgG was detected using the Abbott Architect SARS-CoV-2 IgG Quant II CMIA. A total of 186 paired samples were collected. The accuracy of Fortress LFIA in detecting IgG antibodies to SARS-CoV-2 compared to anti-spike protein detection on Abbott Assay Results: The LFIA had an estimated sensitivity of 92.0% (114/124; 95% confidence interval [CI] 85.7% to 96.1%) and specificity of 93.6% (58/62; 95% CI 84.3% to 98.2%) using the Abbott assay as reference standard (using the threshold for positivity of 7.10 BAU/ml) Conclusions: Fortress LFIA performs well in the detection of antibody responses for intended purpose of population level surveillance but does not meet criteria for individual testing.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody lateral flow assay for antibody prevalence studies following vaccination: a diagnostic accuracy study

Background: Lateral flow immunoassays (LFIAs) are able to achieve affordable, large scale antibody testing and provide rapid results without the support of central laboratories. As part of the development of the REACT programme extensive evaluation of LFIA performance was undertaken with individuals following natural infection. Here we assess the performance of the selected LFIA to detect antibody responses in individuals who have received at least one dose of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. Methods: This was a prospective diagnostic accuracy study. Sampling was carried out at renal outpatient clinic and healthcare worker testing sites at Imperial College London NHS Trust. Two cohorts of patients were recruited; the first was a cohort of 108 renal transplant patients attending clinic following two doses of SARS-CoV-2 vaccine, the second cohort comprised 40 healthcare workers attending for first SARS-CoV-2 vaccination and subsequent follow up. During the participants visit, finger-prick blood samples were analysed on LFIA device, while paired venous sampling was sent for serological assessment of antibodies to the spike protein (anti-S) antibodies. Anti-S IgG was detected using the Abbott Architect SARS-CoV-2 IgG Quant II CMIA. A total of 186 paired samples were collected. The accuracy of Fortress LFIA in detecting IgG antibodies to SARS-CoV-2 compared to anti-spike protein detection on Abbott Assay Results: The LFIA had an estimated sensitivity of 92.0% (114/124; 95% confidence interval [CI] 85.7% to 96.1%) and specificity of 93.6% (58/62; 95% CI 84.3% to 98.2%) using the Abbott assay as reference standard (using the threshold for positivity of 7.10 BAU/ml) Conclusions: Fortress LFIA performs well in the detection of antibody responses for intended purpose of population level surveillance but does not meet criteria for individual testing.

Diabetic kidney disease and pregnancy outcomes: a systematic review

Introduction: We systematically reviewed all relevant literature on diabetic kidney disease (DKD) and pregnancy published in the last 20 years to provide accurate and up-to-date information to inform family planning and maternal care. Methods: A systematic review was completed in PubMed and Embase. Papers reporting maternal, fetal or renal outcomes of pregnant women with DKD published between 2001 and 2020 were included. Results: 799 potentially relevant articles were identified, 731 of which were excluded on abstract alone. 68 full-text articles were reviewed and 15 papers were included as they met the selection criteria but were heterogeneous for size, study setting and years studied. The definition of DKD varied between papers and changed over time. 843 women with 873 pregnancies were included. There were high rates of pre-eclampsia and caesarean section, up to 64% and 100% respectively. Prematurity and neonatal intensive care admission were common, reported in up to 100% and 75%, respectively. Maternal and fetal complications were more common with more severe proteinuria and renal impairment. Pregnancy did not hasten progression of DKD. Discussion: Adverse pregnancy outcomes are frequently encountered and correlate with degree of proteinuria and renal impairment. This information enables individualised risk stratification when a woman is considering pregnancy.

Humoral and T-cell responses to SARS-CoV-2 vaccination in patients receiving immunosuppression

OBJECTIVE

There is an urgent need to assess the impact of immunosuppressive therapies on the immunogenicity and efficacy of SARS-CoV-2 vaccination.

METHODS

Serological and T-cell ELISpot assays were used to assess the response to first-dose and second-dose SARS-CoV-2 vaccine (with either BNT162b2 mRNA or ChAdOx1 nCoV-19 vaccines) in 140 participants receiving immunosuppression for autoimmune rheumatic and glomerular diseases.

RESULTS

Following first-dose vaccine, 28.6% (34/119) of infection-naïve participants seroconverted and 26.0% (13/50) had detectable T-cell responses to SARS-CoV-2. Immune responses were augmented by second-dose vaccine, increasing seroconversion and T-cell response rates to 59.3% (54/91) and 82.6% (38/46), respectively. B-cell depletion at the time of vaccination was associated with failure to seroconvert, and tacrolimus therapy was associated with diminished T-cell responses. Reassuringly, only 8.7% of infection-naïve patients had neither antibody nor T-cell responses detected following second-dose vaccine. In patients with evidence of prior SARS-CoV-2 infection (19/140), all mounted high-titre antibody responses after first-dose vaccine, regardless of immunosuppressive therapy.

CONCLUSION

SARS-CoV-2 vaccines are immunogenic in patients receiving immunosuppression, when assessed by a combination of serology and cell-based assays, although the response is impaired compared with healthy individuals. B-cell depletion following rituximab impairs serological responses, but T-cell responses are preserved in this group. We suggest that repeat vaccine doses for serological non-responders should be investigated as means to induce more robust immunological response.

Informing the Risk of Kidney Transplantation Versus Remaining on the Waitlist in the Coronavirus Disease 2019 Era

INTRODUCTION

There are limited data pertaining to comparative outcomes of remaining on dialysis versus kidney transplantation as the threat of coronavirus disease 2019 (COVID-19) remains. In this study we delineate the differential risks involved using serologic methods to help define exposure rates.

METHODS

From a cohort of 1433 patients with end-stage kidney disease (ESKD), we analyzed COVID-19 infection rates and outcomes in 299 waitlist patients compared with 237 transplant recipients within their first year post-transplant. Patients were followed over a 68-day period from the time our transplant program closed due to COVID-19.

RESULTS

The overall mortality rates in waitlist and transplant populations were equivalent (P = 0.69). However, COVID-19 infection was more commonly diagnosed in the waitlist patients (P = 0.001), who were more likely to be tested by reverse transcriptase polymerase chain reaction (P = 0.0004). Once infection was confirmed, mortality risk was higher in the transplant patients (P = 0.015). The seroprevalence in dialysis and transplant patients with undetected infection was 18.3% and 4.6%, respectively (P = 0.0001). After adjusting for potential screening bias, the relative risk of death after a diagnosis of COVID-19 remained higher in transplant recipients (hazard ratio = 3.36 [95% confidence interval = 1.19-9.50], P = 0.022).

CONCLUSIONS

Although COVID-19 infection was more common in the waitlist patients, a higher COVID-19‒associated mortality rate was seen in the transplant recipients, resulting in comparable overall mortality rates.

Identification of Patient Characteristics Associated With SARS-CoV-2 Infection and Outcome in Kidney Transplant Patients Using Serological Screening

BACKGROUND

From population studies, solid organ transplant recipients are at increased risk of mortality from RT-PCR confirmed COVID-19 infection. The risk factors associated with infection acquisition and mortality in transplant recipients using serological data have not been reported.

METHODS

From 1725 maintenance transplant recipients, 855 consecutive patients were screened for SARS-CoV-2 antibodies. Serological screening utilized assays to detect both the N protein and receptor binding domain antibodies. Thirty-three of 855 (3.9%) of the screened patients had prior infection confirmed with RT-PCR. Twenty-one additional patients from our 1725 maintenance cohort with RT-PCR confirmed infection were included in our analysis.

RESULTS

Eighty-nine of 855 (10.4%) patients tested positive for SARS-CoV-2 antibodies. Fifty-nine of 89 (66.3%) cases were patients newly identified as exposed, while 30/89 (33.7%) seropositive patients had previous infection confirmed by RT-PCR. A diagnosis of SARS-CoV-2 (RT-PCR or Ab+) was associated with being from a noncaucasoid background, P = 0.015; having a diagnosis of diabetes, P = 0.028 and a history of allograft rejection, P < 0.01. Compared with the RT-PCR+ cohort, patients with serological-proven infection alone were more likely to be receiving tacrolimus monotherapy, P < 0.01, and less likely to have a diagnosis of diabetes, P = 0.012. Seventeen of 113 (15.0%) of all patients with infection (RT-PCR and Ab+) died. Risk factors associated with survival were older age, odds ratio (OR): 1.07 (1.00-1.13), P = 0.041; receiving prednisolone, OR: 5.98 (1.65-21.60), P < 0.01 and the absence of diabetes, OR: 0.27 (0.07-0.99), P = 0.047.

CONCLUSIONS

This study identifies risk factors and outcome for COVID-19 infection incorporating data on serologically defined infection and highlights the important contribution of immunosuppression regimen on outcomes.

Glomerular Disease and Pregnancy

Nephrologists are routinely involved in the care of pregnant women with glomerulonephritis. Prepregnancy counseling is vital to inform women of the potential risks of pregnancy and to reduce those risks by optimizing clinical status and medications. In general, for all glomerulonephritides, the best pregnancy outcomes are achieved when the disease is in remission and the woman has preserved renal function with no proteinuria or hypertension. Each glomerulonephritis has specific considerations, for example in lupus nephritis, mycophenolate is teratogenic and must be stopped at least 6 weeks before conception, hydroxychloroquine is recommended for all pregnant women, and flares are frequently encountered and must be treated appropriately. De novo glomerulonephritis should be considered when significant proteinuria is found early in pregnancy or an acute kidney injury with active urine is encountered. Biopsy can be safely undertaken in the first trimester. Treatment is often with corticosteroids, azathioprine, and/or tacrolimus. Rituximab is increasingly used for severe disease. Women with glomerulonephritis should ideally be managed in a joint renal-obstetric clinic. This review details the approach to the care of women with glomerulonephritis from prepregnancy counseling, through antenatal care and delivery, to the postpartum period. Special attention is given to medications and treatment of glomerulonephritis in pregnancy.

P1208TREATMENT OUTCOMES IN PERITONEAL DIALYSIS PERITONITIS ARE NOT AFFECTED BY DEGREE OF RESIDUAL RENAL FUNCTION

Background and Aims

Early studies in peritonitis showed no difference in outcomes between anuric and non-anuric patients, despite pharmacokinetic studies showing the effect of residual renal function (RRF) on antibiotic clearance. Recent work identified a relationship between preserved RRF and treatment failure in gram-positive and culture-negative peritonitis. Our centre uses empiric vancomycin and gentamicin dosed by weight (both drugs) and by RRF (gentamicin). We sought to examine whether RRF is associated with treatment failure in our population.

Method

We retrospectively identified all episodes of PD peritonitis between January 2014 and July 2019 including demographic and clinical information. The RRF measured closest to the peritonitis episode was used. Treatment failure was defined as death, catheter removal or relapse.

Results

189 peritonitis episodes occurred in 128 patients (43% female, mean age 61.3±17.9). 80 episodes were caused by gram-positive bacteria, 49 gram-negative, 51 culture-negative, 5 fungal and 4 polymicrobial. 21, 88 and 61 episodes occurred in patients with a creatinine clearance &lt;0.5, 0.5-5, and &gt;5ml/min respectively. Creatinine clearance data was unavailable in 21 patients.

Treatment failure occurred in 72 cases (38%) (19 relapses, 52 catheter removals, 7 deaths). Treatment failure for all bacterial peritonitis episodes was not affected by RRF as compared to anuric patients: 0.5-5 (OR 0.41, 95% CI 0.12-1.35, p 0.14) or &gt;5 (OR 0.90, 95% CI 0.22-3.67, p 0.88). There was no difference in outcome in sub-group analysis by type of organism. Antibiotic concentrations did not differ between the RRF groups.

Conclusion

Although limited by small numbers we found no association between the degree of RRF and outcome. We hypothesise this is because we monitor antibiotic concentrations and therefore dose antibiotics appropriate to the level of RRF. In PD peritonitis regimes that adjust for RRF there is no impact of RRF on treatment outcomes.

Comparison of Sleep Patterns in Vietnam Veterans With and Without Posttraumatic Stress Disorder Using Wrist Actigraphy

STUDY OBJECTIVES

Disturbed sleep is a hallmark feature of posttraumatic stress disorder (PTSD). However, few studies have examined sleep objectively in individuals with PTSD compared to trauma-exposed controls. This study used wrist actigraphy to measure and compare sleep patterns in trauma-exposed Australian Vietnam veterans (VV) with and without PTSD.

METHODS

Trauma-exposed Australian VV with and without PTSD were recruited from the PTSD Initiative. VV wore wrist accelerometers over 14 days and completed daily sleep diaries. Sleep parameters were compared between groups including sleep latency (SL), time in bed (TIB), total sleep time (TST), wake after sleep onset (WASO), and movement index (MI). Night-to-night and overall within-individual variability were assessed by root mean squared successive differences and comparison of individual standard deviations. Correlations between sleep diary (self-reported) and wrist actigraphy (objective) variables were also assessed.

RESULTS

A total of 40 male VV (20 with PTSD) participated in the study. We found no difference in sleep patterns determined by wrist actigraphy between groups with the exception of reduced SL in VV with PTSD (3.9 ± 0.9 versus 4.9 ± 1.4 minutes, P < .05). Overall within-individual variability was significantly greater in VV with PTSD for TIB, TST, WASO, and MI. Self-reported and objective TST and WASO were more strongly correlated in VV without PTSD than those with PTSD.

CONCLUSIONS

Although there were no significant differences in sleep parameters, VV with PTSD had increased within-individual overall sleep variability and reduced correlation between self-reported and objective sleep parameters compared to trauma-exposed controls. Further evaluation of extended sleep patterns by actigraphy in VV with PTSD is warranted.

Burkholderia cepacia: An Outbreak in the Peritoneal Dialysis Unit

Burkholderia cepacia is a ubiquitous, opportunistic, environmental gram-negative bacillus which most commonly affects cystic fibrosis and immunocompromised patients. Rarely, it can cause peritoneal dialysis (PD) exit-site infection (ESI). Information relating to predisposing factors, clinical course, and treatment options for B. cepacia ESIs is limited. Although reports of B. cepacia healthcare-associated infections exist, outbreaks in PD units have not previously been reported. A recent outbreak of B. cepacia ESI in our PD unit provided a unique opportunity to study B. cepacia ESIs and to outline an approach to investigating such an outbreak.

After unexpectedly identifying B. cepacia as the cause of PD catheter ESIs in 3 patients over an 11-week period, we began systematically screening our PD population for B. cepacia exit-site colonization. A further 6 patients were found to be affected, 3 with asymptomatic colonization and 3 with symptomatic B. cepacia ESI. Four of the 6 developed tunnel infections requiring multiple courses of antibiotic treatment, and 3 patients required catheter removal; 2 patients with symptomatic ESIs without tunnel involvement responded to oral and topical antibiotics. Further investigation implicated 4% chlorhexidine aqueous bodywash used by all patients as the probable source of the outbreak.

This is the first reported outbreak of B. cepacia ESIs. We noted an association between diabetes mellitus and refractory/more extensive infection. Our experience suggests that isolated ESIs can be treated successfully with oral antibiotics whereas tunnel infections generally require catheter removal.

Detailed Polysomnography in Australian Vietnam Veterans With and Without Posttraumatic Stress Disorder

STUDY OBJECTIVES

Recent results from the PTSD Initiative, a cross-sectional cohort study in Australian Vietnam veterans (VV) with and without posttraumatic stress disorder (PTSD), demonstrated an increased prevalence of self-reported sleep disturbances in those with PTSD. This study aimed to objectively assess the prevalence of sleep disorders in the same cohort using detailed polysomnography (PSG).

METHODS

Participants from the PTSD Initiative were recruited to undergo PSG. PTSD status was determined with the Clinician Administered PTSD Scale for DSM-5 (CAPS-5). Subjective sleep information was attained via structured questionnaires. Data from single night PSG were compared between trauma-exposed VV with and without PTSD.

RESULTS

A total of 74 trauma-exposed male VV (40 with PTSD) underwent PSG (prospective n = 59, retrospective n = 15). All PSG parameters were similar between groups. No difference was seen in PSG-diagnosed obstructive sleep apnea (OSA) or periodic limb movements of sleep (PLMS). VV with PTSD showed a trend toward increased duration of sleep with oxygen saturations < 90% (10% versus 1.8%; P = .07). VV with PTSD reported increased sleep onset latency (42.4 versus 13.3 minutes; P < .01); were less likely to report sleeping well (32.5% versus 67.5%; P < .01); had higher OSA risk using Berlin Questionnaire (BQ) (70% versus 38.2%; P < .01); and had higher rates of partner-reported limb movements (56.4% versus 17.6%; P < .01). No association between PSG-diagnosed OSA and PTSD severity was evident.

CONCLUSIONS

In Australian VV with and without PTSD, no difference was seen across all PSG parameters including the diagnosis and severity of OSA and PLMS. However, VV with PTSD demonstrated an increased perception of sleep disturbances.

Stress-Induced Ketoacidosis in Spinal Muscular Atrophy: An Under-Recognized Complication

Ketoacidosis is an important but under-recognized complication of neuromuscular disease, in particular spinal muscular atrophy. This easily treatable condition is largely overlooked in best practice guidelines, and lack of awareness contributes to adverse outcomes in this patient population. Neuromyopathy associated ketosis should be considered in all patients with severe muscle wasting presenting with an elevated anion gap metabolic ketoacidosis. Treatment is simple, effective, and should be instituted early. Our report of a 50-year-old patient with type 2 spinal muscular atrophy who presents with recurrent ketoacidosis aims to increase awareness of neuromyopathy associated ketosis as a clinical entity, and to enhance its early recognition and timely treatment in order to improve patient outcomes.

ECG-derived spatial QRS-T angle is associated with ICD implantation, mortality and heart failure admissions in patients with LV systolic dysfunction

Background

Increased spatial QRS-T angle has been shown to predict appropriate implantable cardioverter defibrilIator (ICD) therapy in patients with left ventricular systolic dysfunction (LVSD). We performed a retrospective cohort study in patients with left ventricular ejection fraction (LVEF) 31–40% to assess the relationship between the spatial QRS-T angle and other advanced ECG (A-ECG) as well as echocardiographic metadata, with all-cause mortality or ICD implantation for secondary prevention.

Methods

534 patients ≤75 years of age with LVEF 31–40% were identified through an echocardiography reporting database. Digital 12-lead ECGs were retrospectively matched to 295 of these patients, for whom echocardiographic and A-ECG metadata were then generated. Data mining was applied to discover novel ECG and echocardiographic markers of risk. Machine learning was used to develop a model to predict possible outcomes.

Results

49 patients (17%) had events, defined as either mortality (n = 16) or ICD implantation for secondary prevention (n = 33). 72 parameters (58 A-ECG, 14 echocardiographic) were univariately different (p<0.05) in those with vs. without events. After adjustment for multiplicity, 24 A-ECG parameters and 3 echocardiographic parameters remained different (p<2x10^-3). These included the posterior-to-leftward QRS loop ratio from the derived vectorcardiographic horizontal plane (previously associated with pulmonary artery pressure, p = 2x10^-6); spatial mean QRS-T angle (134 vs. 112°, p = 1.6x10^-4); various repolarisation vectors; and a previously described 5-parameter A-ECG score for LVSD (p = 4x10^-6) that also correlated with echocardiographic global longitudinal strain (R² = - 0.51, P < 0.0001). A spatial QRS-T angle >110° had an adjusted HR of 3.4 (95% CI 1.6 to 7.4) for secondary ICD implantation or all-cause death and adjusted HR of 4.1 (95% CI 1.2 to 13.9) for future heart failure admission. There was a loss of complexity between A-ECG and echocardiographic variables with an increasing degree of disease.

Conclusion

Spatial QRS-T angle >110° was strongly associated with arrhythmic events and all-cause death. Deep analysis of global ECG and echocardiographic metadata revealed underlying relationships, which otherwise would not have been appreciated. Delivered at scale such techniques may prove useful in clinical decision making in the future.

Lactation Ketoacidosis: An Unusual Entity and a Review of the Literature

A 31-year-old woman presented to the hospital with symptoms of nausea, malaise, and emesis. She was breastfeeding her 10-month-old infant. She was found to have severe ketoacidosis. The patient was not in diabetic ketoacidosis or alcoholic ketoacidosis; nor had she ingested any toxins. After she was admitted to the hospital, received intravenous fluids, and stopped breastfeeding, her symptoms resolved. She was found to have lactation ketoacidosis, an uncommon condition in humans. A review of all causes of ketoacidosis is presented with special emphasis on lactation ketocacidosis.

Danazol: an effective option in acquired amegakaryocytic thrombocytopaenic purpura

Acquired amegakaryocytic thrombocytopaenic purpura (AATP) is a rare haematological condition characterised by isolated thrombocytopaenia with normal other cell lines. It is often initially misdiagnosed as immune thrombocytopaenic purpura but has characteristic bone marrow findings of reduced megakaryocyte numbers. The optimal treatment of AATP is not clearly defined but revolves around immunosuppressive therapies. We report a case of successful treatment of AATP with danazol, an antioestrogenic medication. We also review the aetiologies and pathogenesis of the disorder and suggest that danazol should be considered as an effective alternative to potent immunosuppression in AATP.

Response-reinforcer relations and the maintenance of behavior

The effects on pigeons' key pecking of unsignaled delays of reinforcement and response-independent reinforcement were compared after either variable-interval or differential-reinforcement-of-low-rate baseline schedules. One 30-min session arranging delayed reinforcement and one 30-min session arranging response-independent reinforcement were conducted daily, 6 hr apart. A within-subject yoked-control procedure equated reinforcer frequency and distribution across the two sessions. Response rates usually were reduced more by response-independent than by delayed but response-contingent delivery of reinforcers. Under both schedules, response rates were lower when obtained delays were greater. These results bear upon methodological and conceptual issues regarding comparisons of contingencies that change the temporal response-reinforcer relations.

A Qualitative Assessment of South African Adolescents' Motivations For and Against Substance Use and Sexual Behavior

Focus groups (N = 15 groups; eight with girls, seven with boys) with adolescents in high schools near Cape Town, South Africa were used to conduct a qualitative investigation of reported reasons for using and not using substances, and for having and not having sex. Adolescents reported Enhancement, Negative States, Social, and Aversive Social motivations for both substance use and sexual behavior. In addition, being addicted as a reason for using drugs and rape as a context for sexual behavior were frequently reported. Motivations against behaviors included Physical/Behavioral Consequences, Ethical Objections, Social Disapproval, and Activities or Future Orientation reasons. Preventive interventions should address existing motivations for and against substance use and sexual behavior to acknowledge adolescents' experiences in context.

Maternal recall bias, obstetric history and schizophrenia

BACKGROUND

This study sought to clarify the role of obstetric complications (OCs) and maternal recall bias for patients with first episodes of schizophrenia and those at increased risk of the disorder.

METHOD

Subjects at high risk of schizophrenia were compared with people with first-episode schizophrenia and with healthy volunteers. Consenting mothers of subjects were interviewed using a standardised questionnaire for the recall of OCs, and OCs were also measured from records collected at the time of pregnancy and delivery.

RESULTS

High-risk subjects and first-episode patients had higher rates of OCs recalled by their mother than controls, but hospital records showed no differences in OCs between groups. The number of OCs recalled by mothers of the high-risk group was not related to whether the mother had schizophrenia or not, but was related to the maternally rated abnormal childhood behaviour as measured by the Child Behaviour Checklist.

CONCLUSIONS

These results suggest that studies that rely on maternal recall alone are susceptible to bias. The excess of OCs recalled by the mother could be related to abnormal behaviour in their child rather than maternal illness, family history or psychotic symptoms.

Further characterization of the discriminative stimulus effects of buspirone using monoamine agonists and antagonists in the pigeon

White Carneau pigeons were trained to discriminate 1.0 mg/kg buspirone from saline when key pecking was maintained under a fixed-ratio 30 schedule of food presentation. Buspirone (0.3-10.0 mg/kg), the serotonin 1A (5-HT(1A)) agonist 8-OH-DPAT (0.1-1mg/kg), the buspirone analog BMY 7378 (3.0-5.6mg/kg), the mixed 5-HT(1A/1B) agonist RU 24969 (3.0-10.0mg/kg) and the 5-HT(1A) agonist spiroxatrine (0.1-1.0mg/kg) occasioned at least 80% buspirone-appropriate responding in all subjects tested. Administration of the 5-HT(1B) agonist (TFMPP 0.1-10.0mg/kg) or the 5-HT(3) antagonist (MDL 72222 (3.0-17.0mg/kg) resulted in primarily saline-key responding. The dopamine receptor antagonist chlorpromazine (1.0-17.0mg/kg), the specific D-2 receptor antagonist eticlopride (0.03-0.56mg/kg), the noradrenergic alpha-2 antagonist yohimbine (0.1-1.0mg/kg), the alpha-2 agonist clonidine (0.003-0.10mg/kg) and (+/-) and (-) propranolol (3.0-30.0mg/kg) all produced primarily saline-appropriate responding. Coadministration of the beta-adrenergic agonist isoproterenol (1.0-5.6mg/kg) or the 5-HT(1A) partial agonist BMY 7378 (0.01-10.0mg/kg) with 1.0mg/kg buspirone did not block the discriminative stimulus effects of buspirone. However, 3.0-10.0mg/kg BMY 7378, in combination with a lower dose of buspirone (0.3mg/kg) decreased drug-key responding to approximately 50%. Results from the present study suggest that (1) the discriminative stimulus effects of buspirone, 8-OH-DPAT, BMY 7378, RU 24969 and spiroxatrine are mediated through the 5-HT(1A) receptor; (2) buspirone's discriminative stimulus effects do not interact with the noradrenergic or dopaminergic system; and 3) under this procedure BMY 7378 was a partial agonist at 5-HT(1A) receptors.

Relationship between behavioral and physiological indicators of pain, critical care patients' self-reports of pain, and opioid administration

OBJECTIVES

To examine the accuracy of inferences about critical care patients' pain based on physiological and behavioral indicators and to assess the relationship between registered nurse and patient pain scores and doses of opioids administered.

DESIGN

Descriptive, comparative analysis.

SETTING

Three intensive care units and two postanesthesia care units in two hospitals.

SUBJECTS

Fourteen critical care nurses who conducted 114 pain assessments on 31 surgical patients.

INTERVENTIONS

Nurses used a pain assessment and intervention notation algorithm that contained lists of behavioral and physiological indicators of pain to make inferences about a patient's pain intensity. Fourteen registered nurses completed up to five pain assessments on each patient over a 4-hr period. Following both the physiological and behavioral ratings, nurses rated the patients' pain intensity, using a 0 to 10 numeric rating scale, and they asked patients to provide a self-report of pain intensity, using a similar numeric rating scale. Nurses then administered an intravenous dose of an opioid from a sliding scale prescription.

MEASUREMENTS AND MAIN RESULTS

Moderate-to-strong correlations were found between the number of behavioral indicators at times 1 through 5 and between the number of physiological indicators and nurses' ratings of the patients' pain intensity at times 1 through 4 (p < .05). Although nurses' pain ratings were consistently lower than patients' pain ratings across the five time points, these differences were not significant. The amount of opioid analgesic administered by the nurse correlated more frequently with nurses' pain ratings than with patients' self-reports of pain intensity.

CONCLUSIONS

The use of a detailed, standardized pain assessment and intervention notation algorithm that incorporates behavioral and physiological indicators may assist healthcare professionals in making relatively accurate assessments of a patient's pain intensity. Further research is needed to determine the specific decision-making processes and criteria that healthcare professionals use to choose doses of analgesics to administer to critically ill patients.

Blockade of behavioral effects of bretazenil by flumazenil and ZK 93,426 in pigeons

Benzodiazepine receptor partial agonists manifest full efficacy in preclinical tests of anxiolytic drug action but do not fully reproduce the discriminative stimulus effects of benzodiazepine receptor full agonists in pigeons. The partial agonist, bretazenil, binds to both diazepam-sensitive and diazepam-insensitive GABAA receptors. Previous studies have suggested a role for each of these receptor populations in some behavioral effects of bretazenil in pigeons. A possible role for these receptor subtypes in the behavioral effects of bretazenil was further investigated through drug interaction studies with the benzodiazepine receptor antagonists, flumazenil and ZK 93,426. Whereas flumazenil binds with high affinity to both receptor isoforms, ZK 93,426 binds preferentially to diazepam-sensitive binding sites. Bretazenil markedly increased punished responding of pigeons without significantly affecting nonpunished responding. In pigeons discriminating the full benzodiazepine receptor agonist, midazolam, from saline, bretazenil produced only 60-75% maximal effect. Flumazenil and ZK 93,426 neither increased punished responding nor substituted for midazolam, but dose-dependently blocked the effects of bretazenil on punished responding. Flumazenil also dose-dependently blocked the effects of bretazenil in midazolam-discriminating pigeons, whereas ZK 93,426 only attenuated this effect. These results indicate that bretazenil's actions as a partial agonist at diazepam-sensitive benzodiazepine receptors mediate increases in punished responding and substitution for the discriminative stimulus effects of midazolam in pigeons. The differences in the effects of flumazenil and ZK 93,426 on the discriminative stimulus effects of bretazenil suggest a potential contribution of diazepam-insensitive sites to this behavioral effect.

Clinical judgment and management of postoperative pain in critical care patients

BACKGROUND: Acute pain is a significant problem in critical care patients. Although many barriers to successful assessment and management of pain in critical care patients have been noted, little is known about how critical care nurses make clinical judgments when assessing and managing patients' pain. OBJECTIVE: This qualitative analysis is part of a pilot study evaluating nurses' use of a pain assessment and intervention notation algorithm in patients in critical care areas who have limited communication abilities after abdominal or thoracic surgery. METHOD: Transcribed audiotapes of nurse participants' "thinking aloud" while using the pain assessment and intervention notation algorithm were analyzed by using interpretive phenomenology. The interpretive account is based on 31 tape recordings of 14 nurses caring for 41 patients (12 patients in the ICU and 29 patients in the postanesthesia care unit). FINDINGS: The two domains of clinical judgment found were (1) assessing the patient and (2) balancing interventions. CONCLUSIONS: Many nurses' reports showed that they accurately assessed their patients' needs for analgesics. Through testing of and learning from their patients' responses, nurses were able to give amounts of analgesics that diminished patients' postoperative pain. Additionally, nurses had to balance analgesic administration against the patients' hemodynamic and respiratory conditions, medical plan and prescriptions, and the desires of the patients and the patients' families.

Clinical judgment and management of postoperative pain in critical care patients

BACKGROUND

Acute pain is a significant problem in critical care patients. Although many barriers to successful assessment and management of pain in critical care patients have been noted, little is known about how critical care nurses make clinical judgments when assessing and managing patients' pain.

OBJECTIVE

This qualitative analysis is part of a pilot study evaluating nurses' use of a pain assessment and intervention notation algorithm in patients in critical care areas who have limited communication abilities after abdominal or thoracic surgery.

METHOD

Transcribed audiotapes of nurse participants' "thinking aloud" while using the pain assessment and intervention notation algorithm were analyzed by using interpretive phenomenology. The interpretive account is based on 31 tape recordings of 14 nurses caring for 41 patients (12 patients in the ICU and 29 patients in the postanesthesia care unit).

FINDINGS

The two domains of clinical judgment found were (1) assessing the patient and (2) balancing interventions.

CONCLUSIONS

Many nurses' reports showed that they accurately assessed their patients' needs for analgesics. Through testing of and learning from their patients' responses, nurses were able to give amounts of analgesics that diminished patients' postoperative pain. Additionally, nurses had to balance analgesic administration against the patients' hemodynamic and respiratory conditions, medical plan and prescriptions, and the desires of the patients and the patients' families.

Behavioral and biochemical characterization of benzodiazepine receptor partial agonists in pigeons

The ability of benzodiazepine receptor partial agonists to exhibit full efficacy in preclinical anxiolytic tests, in conjunction with initial clinical results, has suggested the possibility of a reduced clinical side-effect profile compared to benzodiazepine receptor full agonists like diazepam. Because punished behavior of pigeons has been useful in detecting effects of novel anxiolytic drugs, effects of imidazobenzodiazepine and beta-carboline benzodiazepine receptor partial agonists and some related compounds were evaluated in this species. The abilities of these compounds to substitute for the discriminative stimulus effects of the full agonists midazolam also was determined. Intrinsic efficacy was assessed by the degree to which gamma-aminobutyric acid increased ligand potency to displace [(3)H]Ro15-1788 (flumazinil) from membranes of pigeon cerebrum, and ranged from full agonist-like efficacy (Ro 19-5470; 7-(3-cyclopropyl-1,2,4-oxodiazol-5-yl)-5,6-dihydro-5-methyl-4H- imidazo[1,5a]-thieno[3,2-f]diazin-4-one) to minimal gamma-aminobutyric acid potentiations close to that of the antagonist flumazenil (abecarnil and Ro 41-7812; 7-chloro-4,5-dihydro-3-(3-hydroxy-1-propynyl)-5-methyl-6H-imidazo[1,5-a] -[1,4 ]benzodiazepine-6-one). Punished responding was increased markedly by midazolam and by all partial agonists, except Ro 41-7812 and Ro 42-8773 (7-chloro-3-[3-(cyclopropylmethoxy)-1-propynyl]-4,5-dihyro-5 -methyl-6H-imidaz o[1,5-a][1,4]benzodiazepine-6-one), at doses that did not affect nonpunished responding. In contrast to the full substitution generally observed in mammals, all of the partial agonists produced incomplete substitution (40-70%) in the midazolam drug discrimination procedure in pigeons. A positive relationship was observed between the degree of substitution and intrinsic efficacy. The benzodiazepine antagonists, flumazenil and ZK 93,426 (ethyl-5-isopropoxy-4-methoxymethyl-beta-carboline-3-carboxylate), neither increased punished responding nor substituted for midazolam. The results of the present study suggest that benzodiazepine receptor partial agonists and related compounds may provide full anxiolytic activity at doses that do not fully reproduce the subjective effect profile of full agonists.

Effects of ibogaine on responding maintained by food, cocaine and heroin reinforcement in rats

The effects of ibogaine (40 and 80 mg/kg, i.p.), an indole alkaloid proposed for the treatment of drug abuse, were determined in three different groups of rats responding under an FR10 schedule of food, cocaine or heroin reinforcement. Ibogaine (80 mg/kg, i.p.) given 60 min before the start of the session resulted in a 97% decrease in the number of ratios completed under the food reinforcement schedule and resulted in a decrease in responding the following day. Neither 40 mg/kg ibogaine given 60 min prior to the session nor 80 mg/kg given 24 h before the session suppressed responding maintained by cocaine infusions (0.33 mg/infusion). Pretreatment with 80 mg/kg ibogaine either 60 or 90 min prior to the session suppressed cocaine self-administration on the day it was administered and the longer pretreatment continued to suppress responding for 48 h. Responding maintained by heroin (18 micrograms/infusion) was the most sensitive to the effects of ibogaine. Both 40 and 80 mg/kg ibogaine resulted in an almost complete suppression of responding following a 60-min pretreatment period. Responding maintained by heroin returned to control levels the day following the administration of ibogaine.

Anxiolytic and antidepressant mechanisms of 5-HT1A drugs in the pigeon: contributions from behavioral studies

The discovery that compounds acting through 5-hydroxytryptamine (5-HT) receptor subtypes can produce anxiolytic and/or antidepressant therapeutic effects in humans has resulted in considerable interest in the role of the 5-HT receptor system in both anxiety and depressive disorders. Because many of the clinically efficacious 5-HT1A anxiolytic drugs are either ineffective or produce inconsistent results in traditional or standard types of preclinical punishment or conflict procedures with rodents and other nonhuman mammals, there is considerable need for alternative behavioral assays sensitive to and selective for these compounds. In contrast to data with nonhuman mammals, 5-HT1A drugs are quite effective in pigeons studied under a punishment procedure. This paper reviews the use of the pigeon conflict procedure as a method for the detection and analysis of potential anxiolytic drugs acting through 5-HT1A receptors. Additionally, recent studies, also with the pigeon, have indicated that, in contrast to the rat, it is possible to establish an antidepressant such as imipramine as a discriminative stimulus, and then to use this procedure to evaluate the neuropharmacological bases for the behavioral and, presumably, therapeutic actions of these drugs. Using the drug discrimination procedure, it has been possible to examine a number of selective compounds that substitute for imipramine, thereby clarifying specific substrates for the antidepressant activity of this and related drugs. The pigeon promises to be a useful species in the pharmacological analyses of novel anxiolytic drugs and provides new approaches to the analysis and understanding of traditional as well as the more recently introduced antidepressant drugs.

The Good Heart, Good Life survey: self-reported cardiovascular disease risk factors, health knowledge and attitudes among Greek-Australians in Sydney

This survey aimed to assess the prevalence and knowledge of coronary risk factors and self-perceived coronary heart disease risk among Greek-Australians in the Marrickville area of inner Sydney. A random sample of 834 household addresses was selected from the 2,403 households having Greek-Australian surnames on the electoral roll. In each household, one individual aged 18 years or over was selected using a Kish grid, and a questionnaire was administered by a bilingual interviewer. Questions concerned knowledge of and self-reported risk factors for coronary heart disease, and ratings of perceived stress, social support and networks. There was a response rate of 81 per cent of actual Greek-Australian households, a total of 541 interviews (61 per cent women). Most of the sample (86 per cent) were born in Greece and 77 per cent of interviews were administered in Greek. The age-adjusted male prevalences of self-reported smoking, high blood pressure, high blood cholesterol and body mass index over 26 kg/m2 were 44 per cent, 5 per cent, 14 per cent and 58 per cent, respectively. The age-adjusted female prevalences of self-reported smoking, high blood pressure, high blood cholesterol and body mass index over 26 kg/m2 were 19 per cent, 8 per cent, 15 per cent and 40 per cent, respectively. Compared to the National Heart Foundation risk-factor prevalence survey, the prevalence of self-reported high blood pressure was lower, but obesity and, among males, smoking, were higher. Low levels of education and poor English-language skills among older Greek-Australians may be contributing to the problem.(ABSTRACT TRUNCATED AT 250 WORDS)

Neurochemical effects of 5-HT1 receptor ligands in pigeons

Pigeon cerebrospinal fluid was assayed for 5-HT (5-hydroxytryptamine) and catecholamine metabolites after systemic drug injection. The 5-HT1-like receptor agonists 8-hydroxy-(di-n-propylamino)tetralin (8-OH-DPAT), 5-methoxy-3(1,2,3,6-tetrahydropyridin-4-yl)1H indole (RU 24969), 1-(m-trifluoromethylphenyl)piperazine (TFMPP), and 1-(3-chlorphenyl)piperazine (mCPP) decreased levels of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) without altering other metabolites. 5-HIAA decreases occurred at doses of 8-OH-DPAT and RU 24969 that have anti-conflict effects in pigeons, whereas TFMPP and mCPP decreased 5-HIAA only at behaviorally disruptive doses. The novel compound 1-(2-methoxyphenyl)-1-(4-(2-phthalimido)butyl)piperazine (NAN-190), a putative 5-HT1A receptor antagonist, did not affect 5-HIAA, but attenuated the decreases produced by the agonists. NAN-190 and the alpha 1-adrenoceptor antagonist prazosin increased levels of the norepinephrine metabolite 3-methoxy-4-hydroxyphenylethylene glycol and had additive effects when co-administered. The rank order of potency in inhibiting [3H]8-OH-DPAT binding in pigeon cerebrum was 8-OH-DPAT = RU 24969 > NAN-190 >> mCPP > TFMPP. The results support suggestions that decreased 5-HT neurotransmission underlies the anxiolytic-like effects of 5-HT1A receptor agonists in pigeons.

The Psychiatric Technician: TRESPASSER OR WELCOMED ALLY?

1. The increasing shortage of nurses, higher patient acuity levels, and greater demands placed on nursing to meet standards of care have contributed to the use of psychiatric technicians to alleviate the burden on nursing and ensure the delivery of quality patient care. 2. Psychiatric technicians provide care for a select group of patients under the supervision of the primary nurse. The patients assigned to psychiatric technicians require minimal direct nursing intervention. 3. Psychiatric technicians reported increased self-confidence and self-esteem; the nurses were able to perform more professional nursing activities, increasing their job satisfaction and promoting staff retention; and the patients received high-quality care.

Reimbursement of biotherapy: present status, future directions--perspectives of the third-party payer

The mission of insurers is to provide defined financial support for health care therapies deemed appropriate for use in specific clinical situations. In the current health care financial crisis, insurers are faced with keeping costs to a minimum and premiums reasonable. While insurers wish to finance the best available treatment, it is not always fiscally responsible or realistic to fund care provided in investigational therapies. The Blue Cross and Blue Shield Association (BCBSA), as the national coordinating body for local Blue Cross and Blue Shield Plans, assesses the status of new technologies, such as the biotherapy of cancer, through its Technology Evaluation and Coverage (TEC) Program and its Medical Necessity Program. Fundamental to both programs is whether a technology is effective: Does it improve health outcomes? And, if it does, what are its appropriate conditions of use? New technologies demonstrated by clinical research to improve health outcomes and found consistent with other related criteria are considered eligible for coverage by the TEC Program. New technologies not yet established as effective by clinical research and approved through the TEC Program are considered investigational. Most Blue Cross and Blue Shield Plan contracts exclude coverage for such investigational technologies. Most plan contracts also have medical necessity clauses, whereby only medically necessary technology uses are covered. Central to this is clinical research on appropriate medical conditions of use--the focus of the Medical Necessity Program. Valid conclusions on whether a technology works and where and when it works the best presuppose well-designed scientific studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Discriminative stimulus effects of 8-OH-DPAT in pigeons: antagonism studies with the putative 5-HT1A receptor antagonists BMY 7378 and NAN-190

Pigeons were trained to discriminate 0.3 mg/kg of the 5-HT1A receptor agonist 8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT) from saline. RU 24969 (5-methoxy-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole), at doses of 5.6-10 mg/kg, and eltoprazine (5.6 mg/kg), both mixed 5-HT1A/B agonists, substituted completely for 8-OH-DPAT, whereas 3.0-10 mg/kg of the 5-HT1B/C agonist TFMPP (1-(m-trifluromethylphenyl)piperazine) and 0.1-3.0 of the 5-HT3 antagonist MDL 72222 (3-tropanyl-3,5-dichlorobenzoate) yielded only saline-appropriate responses. Substitution for 8-OH-DPAT by eltoprazine and RU 24969, which does not occur in rats, provides in vivo support for the suggestion that the absence of a 5-HT1B receptor in the pigeon allows more complete expression of 5-HT1A-mediated effects. BMY 7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl)]8-azaspirol-[4.5]- decane-7,9-dione) attenuated the 8-OH-DPAT stimulus at doses from 1.0 to 10 mg/kg but, when administered alone, also resulted in approximately 40% 8-OH-DPAT-appropriate responding at the highest dose. NAN-190 (1-(2-methoxyphenyl)-4-[4-(2-phthalamido)butyl)-piperazine (0.3-3.0 mg/kg) produced a dose-dependent and complete antagonism of the 8-OH-DPAT-discriminative stimulus; administered alone NAN-190 resulted only in saline-key responding. NAN-190 also reversed the rate-decreasing effects of higher doses of 8-OH-DPAT. The beta-adrenoceptor antagonist (+/-)-pindolol (5.6-17 mg/kg) antagonized the discriminative stimulus effects of lower 8-OH-DPAT doses but was unable to block the effects of higher doses of 8-OH-DPAT. Prazosin (1.0-10 mg/kg), which like NAN-190, is an alpha 1-antagonist, neither substituted for nor blocked the discriminative stimulus effects of 8-OH-DPAT. These results suggest that NAN-190 is an effective 5-HT1A receptor antagonist in this procedure with pigeons, with no indication of agonist actions, whereas BMY 7378 and pindolol are best characterized as partial 5-HT1A receptor agonists.

Response acquisition with delayed reinforcement

Discrete responses of experimentally naive, food-deprived White Carneaux pigeons (key pecks) or Sprague-Dawley rats (bar or omnidirectional lever presses) initiated unsignaled delay periods that terminated with food delivery. Each subject first was trained to eat from the food source, but no attempt was made to shape or to otherwise train the response. In both species, the response developed and was maintained. Control procedures excluded the simple passage of time, response elicitation or induction by food presentation, type of operandum, food delivery device location, and adventitious immediate reinforcement of responding as the basis for the effects. Results revealed that neither training nor immediate reinforcement is necessary to establish new behavior. The conditions that give rise to both the first and second response are discussed, and the results are related to other studies of the delay of reinforcement and to explanations of behavior based on contingency or correlation and contiguity.