Relationship between autonomic cardiovascular control and obstructive sleep apnoea in persons with spinal cord injury: a retrospective study

Study design

Retrospective study.

Objective

To determine if there is an association between obstructive sleep apnoea (OSA) and blood pressure (BP) pattern or heart rate variability (HRV) in people with spinal cord injury (SCI).

Setting

A state-based spinal cord service in Victoria, Australia.

Methods

We identified 42 subjects who had ambulatory BP monitoring (ABPM) within 6 months of a diagnostic sleep study at Austin Hospital between 2009 and 2014. Markers for autonomic function, including circadian BP pattern and HRV were extracted from the ABPM study database. Apnoea/hypopnoea index (AHI), arousals/hour and oxygen desaturation index were extracted from the sleep study database. Subjects with a nocturnal systolic BP dipping more than 10% of daytime value were defined as dippers, between 10 and 0% were non-dippers and those with a higher night than day systolic BP were reverse dippers. Severity of OSA is classified as non-OSA (AHI < 5), mild (AHI 5-15), moderate (AHI 15-30) and severe (AHI > 30).

Results

Subjects (n = 42) were predominantly male (85.7%), aged 44 ± 15.4 (mean ± SD), with a BMI of 24.4 ± 5.7 (mean ± SD) and mainly tetraplegic (92.9%). There was no difference in AHI, oxygen desaturation index or arousals/hour between dippers, non-dippers and reverse dippers. None of the HRV parameters differed between dippers, non-dippers and reverse dippers. No differences were found in 24 h, night-time, daytime or nocturnal dip in BP between subjects with non-OSA, mild, moderate and severe OSA.

Conclusion

We found no relationship between BP pattern or HRV and the severity of OSA in persons with SCI.

Airway clearance techniques in neuromuscular disorders: A state of the art review

This is a unique state of the art review written by a group of 21 international recognized experts in the field that gathered during a meeting organized by the European Neuromuscular Centre (ENMC) in Naarden, March 2017. It systematically reports the entire evidence base for airway clearance techniques (ACTs) in both adults and children with neuromuscular disorders (NMD). We not only report randomised controlled trials, which in other systematic reviews conclude that there is a lack of evidence base to give an opinion, but also include case series and retrospective reviews of practice. For this review, we have classified ACTs as either proximal (cough augmentation) or peripheral (secretion mobilization). The review presents descriptions; standard definitions; the supporting evidence for and limitations of proximal and peripheral ACTs that are used in patients with NMD; as well as providing recommendations for objective measurements of efficacy, specifically for proximal ACTs. This state of the art review also highlights how ACTs may be adapted or modified for specific contexts (e.g. in people with bulbar insufficiency; children and infants) and recommends when and how each technique should be applied.

Music-assisted relaxation during transition to non-invasive ventilation in people with motor neuron disease: A qualitative case series

For individuals with motor neuron disease, the transition to using non-invasive ventilation has a number of associated stressors, which can negatively impact adherence to ventilation and its benefits to quality of life. Music listening interventions have been linked with a reduction in anxiety and physiological stress responses in mechanically ventilated patients. This article presents four case studies from a feasibility study that investigated the experience and effect of a music-assisted relaxation intervention on anxiety, quality of life, and non-invasive ventilation use during the first 3 months of using non-invasive ventilation. The experiences of these four participants demonstrated how music-assisted relaxation served to distract from non-invasive ventilation and promote relaxation, indicating that for some, music-assisted relaxation could be a useful strategy to optimize their non-invasive ventilation experience. Early music therapy intervention in motor neuron disease progression could be beneficial to address obstacles faced by one participant in using music-assisted relaxation.

Specific sleepiness symptoms are indicators of performance impairment during sleep deprivation

Drivers are not always aware that they are becoming impaired as a result of sleepiness. Using specific symptoms of sleepiness might assist with recognition of drowsiness related impairment and help drivers judge whether they are safe to drive a vehicle, however this has not been evaluated. In this study, 20 healthy volunteer professional drivers completed two randomized sessions in the laboratory - one under 24h of acute sleep deprivation, and one with alcohol. The Psychomotor Vigilance Task (PVT) and a 30min simulated driving task (AusEdTM) were performed every 3-4h in the sleep deprivation session, and at a BAC of 0.00% and 0.05% in the alcohol session, while electroencephalography (EEG) and eye movements were recorded. After each test session, drivers completed the Karolinska Sleepiness Scale (KSS) and the Sleepiness Symptoms Questionnaire (SSQ), which includes eight specific sleepiness and driving performance symptoms. A second baseline session was completed on a separate day by the professional drivers and in an additional 20 non-professional drivers for test-retest reliability. There was moderate test-retest agreement on the SSQ (r=0.59). Significant correlations were identified between individual sleepiness symptoms and the KSS score (r values 0.50-0.74, p<0.01 for all symptoms). The frequency of all SSQ items increased during sleep deprivation (χ(2) values of 28.4-80.2, p<0.01 for all symptoms) and symptoms were related to increased subjective sleepiness and performance deterioration. The symptoms "struggling to keep your eyes open", "difficulty maintaining correct speed", "reactions were slow" and "head dropping down" were most closely related to increased alpha and theta activity on EEG (r values 0.49-0.59, p<0.001) and "nodding off to sleep" and "struggling to keep your eyes open" were related to slow eye movements (r values 0.67 and 0.64, p<0.001). Symptoms related to visual disturbance and impaired driving performance were most accurate at detecting severely impaired driving performance (AUC on ROC curve of 0.86-0.91 for detecting change in lateral lane position greater than the change at a BAC of 0.05%). Individual sleepiness symptoms are related to impairment during acute sleep deprivation and might be able to assist drivers in recognizing their own sleepiness and ability to drive safely.

An expert on every street corner? Methods for eliciting distributions in geographically dispersed opinion pools

Recent publications outline developments in eliciting probabilistic opinions from clinical experts with which to inform structural assumptions and parameter estimates in health economic models. We outline approaches taken to date to elicit probabilistic distributions from experts within the health economic literature and outline the appropriate considerations and the resulting process in developing a new elicitation program with the aim of allowing low-cost elicitation of expert opinion from a heterogeneous and geographically dispersed opinion pool while preserving the essential features of good practice elicitation methods.

Pharmacological and clinical aspects of antiepileptic drug use in the elderly

In this article, epidemiological and clinical aspects related to the use of antiepileptic drugs (AEDs) in the elderly are highlighted. Studies have shown that people with epilepsy receiving AED treatment show important deficits in physical and social functioning compared with age-matched people without epilepsy. To what extent these deficits can be ascribed to epilepsy per se or to the consequences of AED treatment remains to be clarified. The importance of characterizing the effects of AEDs in an elderly population is highlighted by epidemiological surveys indicating that the prevalence of AED use is increased in elderly people, particularly in those living in nursing homes. Both the pharmacokinetics and the pharmacodynamics of AEDs may be altered in old age, which may contribute to the observation that AEDs are among the drug classes most commonly implicated as causing adverse drug reactions in an aged population. Age alone is one of several contributors to alterations in AED response in the elderly; other factors include physical frailty, co-morbidities, dietary influences, and drug interactions. Individualization of dosage, avoidance of unnecessary polypharmacy, and careful observation of clinical response are essential for an effective and safe utilization of AEDs in an elderly population.

Can early extubation and intensive physiotherapy decrease length of stay of acute quadriplegic patients in intensive care? A retrospective case control study

BACKGROUND AND PURPOSE

Respiratory complications remain a major cause of morbidity and mortality in the acute quadriplegic patient population. The literature has suggested that early insertion of a tracheostomy facilitated pulmonary management and an earlier discharge from the intensive care unit (ICU). Recently, a change in practice has meant that these patients are considered for extubation and intensive physiotherapy treatment, including an overnight on-call service, rather than tracheostomy. The aim of the present retrospective, case-controlled study was to determine if either practice resulted in a difference in length of stay in intensive care and if an on-call physiotherapy service for these patients was cost effective.

METHOD

A case control design was used. Between April 1997 and November 1999, seven patients who did not require a tracheostomy were identified; case control subjects were matched for severity with seven patients who did receive a tracheostomy. Length of stay in intensive care and on the acute ward, days from injury to fixation and the overall number of respiratory physiotherapy and night physiotherapy treatments were recorded.

RESULTS

Five of the seven patients in the non-tracheostomy group received on-call overnight physiotherapy treatment, with an average of five sessions over a total of three nights. This group's length of stay in an ICU was significantly less than patients who were tracheostomized (p = 0.02). The overall number of physiotherapy treatments between the two groups was not significantly different.

CONCLUSIONS

The results of this study suggest that if extubation and intensive physiotherapy is undertaken for suitable patients, the length of stay in intensive care can be significantly reduced. This represents a considerable cost saving for ICUs and more than covers the added cost of providing an after hours on-call physiotherapy treatment service. A prospective evaluation is required to confirm these findings.

Risk adjustment for measuring health outcomes: an application in VA long-term care

An empirically derived risk adjustment model is useful in distinguishing among facilities in their quality of care. We used Veterans Affairs (VA) administrative databases to develop and validate a risk adjustment model to predict decline in functional status, an important outcome measure in long-term care, among patients residing in VA long-term care facilities. This model was used to compare facilities on adjusted and unadjusted rates of decline. Predictors of decline included age, time between assessments, baseline functional status, terminal illness, pressure ulcers, pulmonary disease, cancer, arthritis, congestive heart failure, substance-related disorders, and various neurologic disorders. The model performed well in the development and validation databases (c statistics, 0.70 and 0.68, respectively). Risk-adjusted rates and rankings of facilities differed from unadjusted ratings. We conclude that judgments of facility performance depend on whether risk-adjusted or unadjusted decline rates are used. Valid risk adjustment models are therefore necessary when comparing facilities on outcomes.

Cardiac and respiratory activity at arousal from sleep under controlled ventilation conditions

Arousal from sleep is associated with elevated cardiac and respiratory activity. It is unclear whether this occurs because of homeostatic mechanisms or a reflex activation response associated with arousal. Cardiorespiratory activity was measured during spontaneous arousals from sleep in subjects breathing passively on a ventilator. Under such conditions, homeostatic mechanisms are eliminated. Ventilation, end-tidal PCO2, mask pressure, diaphragmatic electromyograph, heart rate, and blood pressure were measured in four normal subjects under two conditions: assisted ventilation and a normal ventilation control condition. In the control condition, there was a normal, sleep-related fall in ventilation and rise in end-tidal PCO2. Subsequently, at an arousal, there was an increase in respiratory and cardiac activity. In the ventilator condition, a vigorous cardiorespiratory response to a spontaneous arousal from sleep remained. These results indicate that sleep-related respiratory stimuli are not necessary for the occurrence of elevated cardiorespiratory activity at an arousal from sleep and are consistent with the hypothesis that such activity is at least in part due to a reflex activation response.

Does diagnostic information contribute to predicting functional decline in long-term care?

BACKGROUND

Compared with the acute-care setting, use of risk-adjusted outcomes in long-term care is relatively new. With the recent development of administrative databases in long-term care, such uses are likely to increase.

OBJECTIVES

The objective of this study was to determine the contribution of ICD-9-CM diagnosis codes from administrative data in predicting functional decline in long-term care.

RESEARCH DESIGN

We used a retrospective sample of 15,693 long-term care residents in VA facilities in 1996.

METHODS

We defined functional decline as an increase of > or =2 in the activities of daily living (ADL) summary score from baseline to semiannual assessment. A base regression model was compared to a full model enhanced with ICD-9-CM codes. We calculated validated measures of model performance in an independent cohort.

RESULTS

The full model fit the data significantly better than the base model as indicated by the likelihood ratio test (chi2 = 179, df = 11, P <0.001). The full model predicted decline more accurately than the base model (R2 = 0.06 and 0.05, respectively) and discriminated better (c statistics were 0.70 and 0.68). Observed and predicted risks of decline were similar within deciles between the 2 models, suggesting good calibration. Validated R2 statistics were 0.05 and 0.04 for the full and base models; validated c statistics were 0.68 and 0.66.

CONCLUSIONS

Adding specific diagnostic variables to administrative data modestly improves the prediction of functional decline in long-term care residents. Diagnostic information from administrative databases may present a cost-effective alternative to chart abstraction in providing the data necessary for accurate risk adjustment.

Primary carcinoid tumor of the pancreas

Serotonin-secreting (carcinoid) tumors of the pancreas are very rare. There are only 13 cases reported since 1963. Liver metastases have not previously been described. We present two patients with primary carcinoid tumor of the pancreas, which metastasized to the liver. These patients differ in their clinical and radiological appearance. Carcinoid tumor should be considered in the differential diagnosis of a pancreatic mass in a patient with carcinoid syndrome, but lack of this syndrome does not exclude the diagnosis.