Short term performance evaluation of a perfluorocopolymer coated gas exchanger for arteriovenous CO2 removal

A new perfluorocopolymer coating for micropore hollow fiber gas exchangers was developed to improve gas exchange, reduce plasma leakage, and reduce blood-surface interactions. The present authors evaluated gas exchanger performance using this new coating in a prospective, randomized, controlled, unblinded, large animal model of CO2 retention. Adult sheep (30-40 kg), under general anesthesia, underwent cannulation of the carotid artery (12 F) and jugular vein (14 F). The perfluorocopolymer coated (n = 5) and uncoated (n = 5) gas exchangers were attached to an arteriovenous CO2 removal (AVCO2R) circuit. Blood gases, CO2 removal, and hemodynamics were monitored throughout the 6 hour study. Average CO2 removal was 107.6 +/- 15.6 ml/min (coated) vs. 93.0 +/- 13.9 ml/min (uncoated; p < 0.01). PaCO2 and CO2 removal for both coated and uncoated did not deteriorate significantly over the study. Average AVCO2R blood flow was 1,130 +/- 25 ml/min (coated) versus 1,101 +/- 79 ml/min (uncoated; p = not significant). Likewise, cardiac output and AVCO2R blood flow did not change over the duration of the study. No significant differences in the pressure gradient or resistance between devices (coated, 6.89 +/- 1.14 mm Hg/L/min; uncoated, 6.42 +/- 0.23 mm Hg/L/min) was noted. The authors concluded that the new perfluorocopolymer coated gas exchanger improved CO2 removal without compromising hemodynamics in an acute performance evaluation.     

Development of an implantable artificial lung: challenges and progress

Unlike dialysis, which functions as a bridge to renal transplantation, or a ventricular assist device, which serves as a bridge to cardiac transplantation, no suitable bridge to lung transplantation exists. Our goal is to design and build an ambulatory artificial lung that can be perfused entirely by the right ventricle and completely support the metabolic O2 and CO2 requirements of an adult. Such a device could realize a substantial clinical impact as a bridge to lung transplantation, as a support device immediately post-lung transplant, and as a rescue and/or supplement to mechanical ventilation during the treatment of severe respiratory failure. Research on the artificial lung has focused on the design, mode of attachment to the pulmonary circulation, and intracorporeal versus paracorporeal placement of the device.     

Adelta and C primary afferents convey dorsal root reflexes after intradermal injection of capsaicin in rats

Antidromic activity was recorded in anesthetized rats from single afferent fibers in the proximal ends of cut dorsal root filaments at the L(4-6) level and tested for responses to acute cutaneous inflammation produced by intradermal injection of capsaicin. This antidromic activity included low-frequency spontaneous firing and dorsal root reflex (DRR) discharges evoked by applying von Frey hairs to the skin of the foot. DRRs could be recorded from both small myelinated (Adelta) and unmyelinated (C) afferent fibers, as well as from large myelinated (Abeta) fibers. After capsaicin was injected intradermally into the plantar skin of the foot, a significant enhancement of DRR activity was seen in Adelta and C fibers but not in Abeta fibers, and this increase lasted for approximately 1 h. This study supports the hypothesis that centrally mediated antidromic activity in Adelta and C primary afferent fibers contributes to the development of neurogenic inflammation, presumably by release of inflammatory substances in the periphery.     

Large and small conductance calcium-activated potassium channels in the GH3 anterior pituitary cell line

Single Ca²⁺-activated K⁺ channels were studied in membrane patches from the GH₃ anterior pituitary cell line. In excised inside-out patches exposed to symmetrical 150 mM KCl, two channel types with conductances in the ranges of 250–300 pS and 9–14 pS were routinely observed. The activity of the large conductance channel is enhanced by internal Ca²⁺ and by depolarization of the patch membrane. This channel contributes to the repolarization of Ca²⁺ action potentials but has a Ca²⁺ sensitivity at –50 mV that is too low for it to contribute to the resting membrane conductance. The small conductance channel is activated by much lower concentrations of Ca²⁺ at –50 mV, ad its open probability is not strongly voltage sensitive. In cell-attached patches from voltage-clamped cells, the small conductance channels were found to be active during slowly decaying Ca²⁺-activated K⁺ tails currents and during Ca²⁺-activated K⁺ currents stimulated by thyrotropin-releasing hormone induced elevations of cytosolic calcium. In cell-attached patches on unclamped cells, the small conductance channels were also active at negative membrane potentials when the frequency of spontaneously firing action potentials was high or during the slow afterhyperpolarization following single spontaneous action potentials of slightly prolonged duration. The small conductance channel may thus contribute to the regulation of membrane excitability.     

Selected testicular enzymes as biochemical markers for procarbazine-induced testicular toxicity

Single doses of procarbazine (MIH) were injected IP at 0, 50, 100, 200, and 400 mg/kg body weight to CD-1 male mice. Activities of hyaluronidase, lactate dehydrogenase isoenzyme-X, and the dehydrogenases of sorbitol, -glycerophosphate, glucose-6-phosphate, malate, isocitrate, and glyceraldehyde-3-phosphate in the testes of the mice were determined and correlated with changes in spermatogenic cell types in seminiferous tubules. All enzyme activities were higher than controls or remained unchanged on days 10–20 after drug treatment. Activities of hyaluronidase, sorbitol dehydrogenase, and lactate dehydrogenase isoenzyme-X decreased significantly to below normal levels on day 30 after drug treatment for all doses, whereas those of the other five dehydrogenases remained significantly higher than controls. All enzyme activities approached control levels with the concomitant recovery of spermatogenesis by day 60 after drug treatment. Histological examination of seminiferous tubules revealed that premeiotic spermatocytes were significantly reduced on days 10–20 but reappeared on day 30 after MIH treatment (400 mg/kg). The postmeiotic spermatogenic cells were unaffected at the time of MIH treatment, but had disappeared completely on day 30 after drug treatment. MIH, at the highest dosage, selectively destroyed spermatogonia and premeiotic spermatocytes; however spermatozoa and elongated spermatides were unaffected. This study demonstrated that the cytotoxic effect of MIH on spermatogenesis could be evaluated via changes in testicular enzyme activities. The present studies demonstrated that hyaluronidase, sorbitol dehydrogenase, and lactate dehydrogenase isoenzyme-X could serve as useful biochemical markers for assessing testicular toxicity induced by drugs and chemicals.     

To What Extent Do Local Nursing Home Prescribing Patterns Relate to Psychotropic Prescribing in Assisted Living?

ObjectiveIn nursing homes (NHs), psychoactive medication use has received notable attention, but less is known about prescribing in assisted living (AL). This study examined how antipsychotic and antianxiety medication prescribing in AL compares with NHs.DesignObservational, cross-sectional AL data linked to publicly reported NH measures.Setting and ParticipantsRandom sample of 250 AL communities and the full sample of 3371 NHs in 7 states.MethodsWe calculated the percentage of residents receiving antipsychotics and antianxiety medications. For each AL community, we calculated the distance to NHs in the state. Linear models estimated the relationship between AL prescribing and that of the closest and farthest 5 NHs, adjusting for AL characteristics and state fixed effects.ResultsThe prescribing rate of potentially inappropriate antipsychotics (i.e., excluding for persons with recorded schizophrenia and Tourette syndrome) and of antianxiety medications (excluding for those on hospice) in AL was 15% and 21%, respectively. Unadjusted mean antipsychotic prescribing rates were nominally higher in AL than NHs (14.8% vs 14.6%; P = .056), whereas mean antianxiety prescribing was nominally lower in AL (21.2% vs 22.6%; P = .032). In adjusted analyses, AL rates of antipsychotic use were not associated with NH rates. However, being affiliated with an NH was associated with a lower rate of antipsychotic use [b = −0.03; 95% confidence interval (CI) −0.50 to −0.001; P = .043], whereas antianxiety rates were associated with neighboring NHs’ prescribing rates (b = 0.43; 95% CI 0.16–0.70; P = .002).Conclusions and ImplicationsThis study suggests reducing antipsychotic medication use in NHs may influence AL practices in a way not accounted for by local NH patterns. And, because antianxiety medications have not been the focus of national campaigns, they may be more subject to local prescribing behaviors. It seems advantageous to consider prescribing in AL when efforts are implemented to change NH prescribing, as there seems to be related influence whether by affiliation or region.     

Does Public Reporting of Staffing Ratios and Nursing Home Compare Ratings Matter?

ObjectivePublic reporting is a policy to improve quality and increase data transparency. The objective was to examine the association between publicly available staffing ratios and the Five-Star Quality Ratings from Nursing Home Compare over time.DesignPanel data analysis.Setting and ParticipantsAbout 146 nursing homes with complete quarterly data in New Jersey between January 1, 2012, and December 31, 2019.MethodsUsing data from the State of New Jersey Department of Health and Nursing Home Compare, staff-to-resident ratios were trended for registered nurses, licensed practical nurses, and certified nursing assistants by shift and over time. Panel data analysis was used to test the association between the ratios and the ratings.ResultsCompared to 2012, staffing ratios improved slightly for licensed practical nurses but not for registered nurses or certified nursing assistants in 2019 (P < .001). The number of residents assigned doubled at night for all personnel. During the day and evening shifts, registered nurse staffing was significantly associated with the Nursing Home Compare staffing rating (P < .01) but not the overall rating.Conclusions and ImplicationsDecreasing the number of residents assigned to a registered nurse in NHs results in an increase in staffing ratings. Mandatory public reporting holds nursing homes accountable for quality outcomes but does not improve staffing ratios. Quality resident care is the cumulative result of multiple measures inclusive of staffing; therefore, administrators should continue to focus on improving quality in NHs, which may improve staffing ratios across shifts.     

A Profile of Black and Latino Older Adults Receiving Care in Nursing Homes: 2011–2017

ObjectiveTo identify if disparate trends in the access and use of nursing home (NH) services among Black and Latino older adults compared with White older adults persist. Access was operationalized as the NHs that served Black, Latino, and White residents. Use was operationalized as the utilization of NH services by Black, Latino, and White residents.DesignThis was an observational study analyzing facility-level data from LTCfocus for 2011 to 2017.Setting and ParticipantsAll NH residents present in US NHs participating in the Centers for Medicare and Medicaid Services program on the first Thursday in April in the years 2011 to 2017. NHs with fewer than 4500 bed-days per year are excluded in the LCTfocus dataset. Black, Latino, and White were the racial/ethnic groups of interest.MethodsWe calculated the mean percentage of each racial/ethnic group in NHs (Black, Latino, White) annually along with the number of NHs that provided care for these groups. We conducted a simple trend analysis using ordinary least squares to estimate the change in NH access and use by racial/ethnic group over time.ResultsOur NH sample ranged from 15,564 in 2011 to 14,956 in 2017. Latino residents' use of NHs increased by 20.47% and Black residents increased by 11.42%, whereas there was a 1.36% decrease in White residents’ use of NHs. In this 7-year span, there was a 4.44% and 6.41% decline in the number of NHs that serve any Black and Latino older adults, respectively, compared with a 2.26% decline in NHs that serve only White older adults (access).Conclusions and ImplicationsOur findings reveal a continued disproportionate rise in Black and Latino older adults’ use of NHs while the number of NHs that serve this population have declined. This work can inform federal and state policies to ensure access to long-term care services and supports in the community for all older adults and prevent inappropriate NH closures.     

The Hospital Frailty Risk Score Identifies Fewer Cases of Frailty in a Community-Based Cohort of Older Men Than the FRAIL Scale and Frailty Index

ObjectivesThe recently developed Hospital Frailty Risk Score (HFRS) allows ascertainment of frailty from administrative data. We aimed to compare the HFRS against the widely used FRAIL Scale and Frailty Index.DesignPopulation-based cohort study linked to Western Australian Hospital Morbidity Data Collection and Death Registrations.Setting and ParticipantsThe Health in Men Study with frailty determined at Wave 2 (2001/2004), mortality in the 1-year period following Wave 2, and disability at Wave 3 (2008). Participants were 4228 community-based men aged ≥75 years, followed until Wave 3.MeasurementsWe used multivariable regression to determine the association between each frailty measure and outcomes of length of stay (LOS), death, and disability. We also determined if the additional cases of frailty identified by one measure over the other was associated with these outcomes.ResultsOf 4228 men studied, the HFRS (n = 689) identified fewer men as frail than the FRAIL Scale (n = 1648) and Frailty Index (n = 1820). In the fully adjusted models, all 3 frailty measures were associated with longer LOS and mortality, whereas only the FRAIL Scale and Frailty Index were significantly associated with disability. The additional cases of frailty identified by the FRAIL Scale and Frailty Index had longer LOS and greater risks of death and disability. The fully adjusted hazard ratio for death among the additional cases of frailty identified by the FRAIL Scale (compared to being not frail on both HFRS and FRAIL Scale) was 2.14 (95% CI 1.48-3.08).Conclusions and ImplicationsThe HFRS is associated with adverse outcomes. However, it identified approximately 60% fewer men who were frail than the FRAIL Scale and Frailty Index, and the additional cases identified were also at high risks of adverse outcomes. Users of the HFRS should be aware of the differences with other frailty measures.