Epidural Labor Analgesia: Continuous Infusion Versus Patient-Controlled Epidural Analgesia With Background Infusion Versus Without a Background Infusion

The purpose of this study was to compare the total epidural dose of 3 commonly used labor epidural modalities. After local institutional review board approval, 195 laboring parturients received an epidural catheter for labor analgesia. All patients received an initial bolus of 0.1% ropivacaine (10 mL) and fentanyl (100 microg). Maintenance of labor analgesia consisted of ropivacaine 0.1% with fentanyl 2 microg/mL. Patients were then randomly assigned into 3 groups: Group 1 (continuous epidural infusion [CEI]), continuous infusion at 10 mL/h; group 2 (CEI + patient-controlled epidural analgesia [PCEA]), CEI at 5 mL/h with a demand dose of 5 mL allowed every 20 minutes with a 20 mL/h maximum dose; group 3 (PCEA), demand doses only of 5 mL every 15 minutes with a 20 mL/h maximum dose. Measured variables included total epidural dose, total bolus requests and boluses delivered, number of staff interventions, pain Visual Analog Scale (VAS; 0-100), modified Bromage scores, stage I and II labor duration, delivery outcome, and maternal satisfaction after delivery. No differences were noted with respect to pain VAS, modified Bromage scores, stage I and II labor duration, number of staff interventions, delivery outcome, and maternal satisfaction score. Total infusion dose was lower in demand dose only PCEA compared with CEI and CEI + PCEA groups (P = < .01). Demand dose-only PCEA results in less total epidural dose compared with CEI and CEI + PCEA without affecting labor duration, motor block, pain VAS, maternal and neonatal outcomes, and maternal satisfaction. PERSPECTIVE: This article compares 3 commonly used labor epidural delivery modalities (traditional continuous epidural infusion, patient-controlled epidural analgesia with a background infusion, and demand dose-only patient-controlled epidural analgesia). Benefits in epidural dose reduction with demand dose only PCEA does not translate into improved maternal and neonatal outcome.     

Delirium is associated with increased mortality in the geriatric population

Objective: The aim of this study was to investigate the prevalence of delirium and its association with mortality rates in elderly inpatients.

Methods: The medical records of 1435 patients over 65 years old who were treated at a regional university hospital and were referred to the university’s Consultation and Liaison Psychiatry Clinic for psychological evaluation were retrospectively analyzed. Patients with and without a diagnosis of delirium were compared. The National Survival Database was used to determine mortality rates.

Results: The prevalence of delirium was 25.5%. The delirium group was older (p?p?p?Conclusions: Independent of all other factors, delirium is associated with higher mortality risk.     

Asymptomatic SARS-CoV-2 infection: A systematic review and meta-analysis

Quantification of asymptomatic infections is fundamental for effective public health responses to the COVID-19 pandemic. Discrepancies regarding the extent of asymptomaticity have arisen from inconsistent terminology as well as conflation of index and secondary cases which biases toward lower asymptomaticity. We searched PubMed, Embase, Web of Science, and World Health Organization Global Research Database on COVID-19 between January 1, 2020 and April 2, 2021 to identify studies that reported silent infections at the time of testing, whether presymptomatic or asymptomatic. Index cases were removed to minimize representational bias that would result in overestimation of symptomaticity. By analyzing over 350 studies, we estimate that the percentage of infections that never developed clinical symptoms, and thus were truly asymptomatic, was 35.1% (95% CI: 30.7 to 39.9%). At the time of testing, 42.8% (95% prediction interval: 5.2 to 91.1%) of cases exhibited no symptoms, a group comprising both asymptomatic and presymptomatic infections. Asymptomaticity was significantly lower among the elderly, at 19.7% (95% CI: 12.7 to 29.4%) compared with children at 46.7% (95% CI: 32.0 to 62.0%). We also found that cases with comorbidities had significantly lower asymptomaticity compared to cases with no underlying medical conditions. Without proactive policies to detect asymptomatic infections, such as rapid contact tracing, prolonged efforts for pandemic control may be needed even in the presence of vaccination.

COVID-19 surveillance provides real-time information about the epidemiological trajectory of the pandemic, informing risk assessments and mitigation policies around the world. Given that COVID-19 surveillance systems predominantly rely on symptom-based screening, the prevalence of asymptomatic infection is often not fully captured. Cross-sectional surveys, such as mass testing once an outbreak is identified, do not distinguish the truly asymptomatic from the presymptomatic. Often, the follow-up period after testing is too brief to ascertain whether patients subsequently develop symptoms. The percentage of silent infections identified by such studies is thus context specific, as it depends on the setting, phase of the epidemic, and efficiency of contact tracing. By contrast, the prevalence of truly asymptomatic infections should be stable across similar demographic settings, regardless of epidemiological trajectory and contact tracing.Compounded by ambiguities about the different clinical manifestations of the disease, which can lead to misinterpretation of clinical and epidemiological studies (1), there have been substantial aberrations in reports and media coverage claiming the asymptomatic percentage to be as low as 4% (2, 3) or as high as 80 to 90% (4, 5). Similarly, the US Centers for Disease Control and Prevention guidelines for COVID-19 pandemic forecasting offer wide bounds for the asymptomatic percentage, ranging from 10 to 70% (6).Previous meta-analyses of 41 studies (7), 13 studies (8), and 79 studies (9) estimate pooled asymptomaticity ranging from 16 to 20%. Two methodological issues limit the accuracy of these studies. First, pooled asymptomaticity reported in these studies is likely biased downward because they did not account for study designs which have a higher representation of cases experiencing symptoms (10). Second, one of the meta-analyses (7) did not consider biases in reported asymptomaticity that can arise from inadequate longitudinal follow-up. Studies that assess the symptom profile only at the time of testing or do not follow up symptoms for a sufficiently long time period cannot distinguish presymptomatic from asymptomatic infection, overestimating those that are truly asymptomatic.Accurate estimates of true disease prevalence, including asymptomatic infections, are essential to calculate key clinical parameters, project epidemiological trajectories, and optimize mitigation measures. Clinical evidence indicates that viral loads among asymptomatic and symptomatic infections may be comparable (11–15). Unaware of their risk to others, individuals with silent infections are likely to continue usual behavior patterns. Accounting for silent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the assessment of disease control measures is necessary to interrupt community transmission (16). Although the discrepancy between reported incidence and seroprevalence gives a sense of the extent of asymptomaticity, not all symptomatic cases are reported, and not all asymptomatic cases (for instance, those identified on the basis of exposure) are missed. Consequently, it is not sufficient to simply compare the reported cases to results from seroprevalence studies. We therefore conducted a systematic review and meta-analysis of COVID-19 literature reporting laboratory-confirmed infections to estimate the percentage of SARS-CoV-2 infections that are truly asymptomatic. We also investigated differences in asymptomaticity with respect to age, sex, comorbidity, study design, publication date, duration of symptom follow-up, geographic location, and setting.     

Interneurons in the basolateral amygdala

The amygdala is a temporal lobe structure that is the center of emotion processing in the mammalian brain. Recent interest in the amygdala arises from its role in processing fear and the relationship of fear to human anxiety. The amygdaloid complex is divided into a number of subnuclei that have extensive intra and extra nuclear connections. In this review we discuss recent findings on the physiology and plasticity of inputs to interneurons in the basolateral amygdala, the primary input station. These interneurons are a heterogeneous group of cells that can be separated on immunohistochemical and electrophysiological grounds. Glutamatergic inputs to these interneurons form diverse types of excitatory synapses. This diversity is manifest in both the subunit composition of the underlying NMDA receptors as well as their ability to show plasticity. We discuss these differences and their relationship to fear learning.This article is part of a Special Issue entitled ‘Synaptic Plasticity & Interneurons’.     

Cholera in India: an analysis of reports, 1997�C2006

Objective

To more accurately define the annual incidence of cholera in India, believed to be higher than reported to the World Health Organization (WHO).

Methods

We searched the biomedical literature to extract data on the cases of cholera reported in India from 1997 to 2006 and compared the numbers found to those reported annually to WHO over the same period. The latter were obtained from WHO’s annual summaries of reported cholera cases and National health profile 2006, published by India’s Central Bureau of Health Intelligence.

Findings

Of India’s 35 states or union territories, 21 reported cholera cases during at least one year between 1997 and 2006. The state of West Bengal reported cases during all 10 years, while the state of Maharashtra and the union territory of Delhi reported cases during nine, and Orissa during seven. There were 68 outbreaks in 18 states, and 222 038 cases were detected overall. This figure is about six times higher than the number reported to WHO (37 783) over the same period. The states of Orissa, West Bengal, Andaman and Nicobar Islands, Assam and Chhattisgarh accounted for 91% of all outbreak-related cases.

Conclusion

The reporting of cholera cases in India is incomplete and the methods used to keep statistics on cholera incidence are inadequate. Although the data are sparse and heterogeneous, cholera notification in India is highly deficient.