Effects of Zolpidem CR on Sleep and Nocturnal Ventilation in Patients with Heart Failure

Tetraplegia is associated with increased hypoxic ventilatory response during nonrapid eye movement sleep

People with cervical spinal cord injury (SCI) are likely to experience chronic intermittent hypoxia while sleeping. The physiological effects of intermittent hypoxia on the respiratory system during spontaneous sleep in individuals with chronic cervical SCI are unknown. We hypothesized that individuals with cervical SCI would demonstrate higher short- and long-term ventilatory responses to acute intermittent hypoxia (AIH) exposure than individuals with thoracic SCI during sleep. Twenty participants (10 with cervical SCI [9 male] and 10 with thoracic SCI [6 male]) underwent an AIH and sham protocol during sleep. During the AIH protocol, each participant experienced 15 episodes of isocapnic hypoxia using mixed gases of 100% nitrogen (N2 ) and 40% carbon dioxide (CO2 ) to achieve an oxygen saturation of less than 90%. This was followed by two breaths of 100% oxygen (O2 ). Measurements were collected before, during, and 40 min after the AIH protocol to obtain ventilatory data. During the sham protocol, participants breathed room air for the same amount of time that elapsed during the AIH protocol and at approximately the same time of night. Hypoxic ventilatory response (HVR) during the AIH protocol was significantly higher in participants with cervical SCI than those with thoracic SCI. There was no significant difference in minute ventilation (V.E. ), tidal volume (V.T. ), or respiratory frequency (f) during the recovery period after AIH in cervical SCI compared to thoracic SCI groups. Individuals with cervical SCI demonstrated a significant short-term increase in HVR compared to thoracic SCI. However, there was no evidence of ventilatory long-term facilitation following AIH in either group.

Addition of zolpidem to combination therapy with atomoxetine-oxybutynin increases sleep efficiency and the respiratory arousal threshold in obstructive sleep apnoea: A randomized trial

BACKGROUND AND OBJECTIVE

Atomoxetine combined with oxybutynin (Ato-Oxy) has recently been shown to reduce obstructive sleep apnoea (OSA) severity by >60%. However, Ato-Oxy also modestly reduced the respiratory arousal threshold, which may decrease sleep quality/efficiency. We sought to investigate the additional effect of zolpidem with Ato-Oxy on sleep efficiency (primary outcome), the arousal threshold, OSA severity, other standard polysomnography (PSG) parameters, next-day sleepiness and alertness (secondary outcomes).

METHODS

Twelve participants with OSA received 10 mg zolpidem plus Ato-Oxy (80-5 mg, respectively) or Ato-Oxy plus placebo prior to overnight in-laboratory PSG according to a double-blind, randomized, crossover design (1-week washout). Participants were fitted with an epiglottic catheter, a nasal mask and pneumotachograph to quantify arousal threshold and airflow. Next-day sleepiness and alertness were assessed via the Karolinska Sleepiness Scale and a driving simulation task.

RESULTS

The addition of zolpidem increased sleep efficiency by 9% ± 13% (80.9% ± 16.9% vs. 88.2% ± 8.2%, p = 0.037) and the respiratory arousal threshold by 17% ± 18% (-26.6 ± 14.5 vs. -33.8 ± 20.3 cm H₂ O, p = 0.004) versus Ato-Oxy + placebo. Zolpidem did not systematically change OSA severity. Combination therapy was well tolerated, and zolpidem did not worsen next-day sleepiness. However, median steering deviation during the driving simulator task increased following the zolpidem combination.

CONCLUSION

Zolpidem improves sleep efficiency via an increase in the respiratory arousal threshold to counteract potential wake-promoting properties of atomoxetine in OSA. These changes occur without altering the rate of respiratory events or overnight hypoxaemia. However, while the addition of zolpidem does not increase next-day perceived sleepiness, caution is warranted given the potential impact on next-morning objective alertness.

Management of Hypnotics in Patients with Insomnia and Heart Failure during Hospitalization: A Systematic Review

BACKGROUND

Heart failure is a chronic, progressive syndrome of signs and symptoms, which has been associated to a range of comorbidities including insomnia. Acute decompensation of heart failure frequently leads to hospital admission. During hospital admission, long-term pharmacological treatments such as hypnotics can be modified or stopped.

AIM

To synthesize the scientific evidence available about the effect of withdrawing hypnotic drugs during hospital admission in patients with decompensated heart failure and insomnia.

METHOD

A systematic review of the literature following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines was carried out in the following scientific databases: PubMed, Scopus, Dialnet and Cochrane.

INCLUSION CRITERIA

studies including a population of adults with heart failure and sleep disorders in treatment with hypnotics and admitted to hospital, studies written in English or Spanish and published until June 2020.

EXCLUSION CRITERIA

studies involving children, patients admitted to intensive care and patients diagnosed with sleep apnea.

RESULTS

We identified a total of 265 documents; only nine papers met the selection criteria. The most frequently used drugs for the treatment of insomnia in patients with heart failure were benzodiazepines and benzodiazepine agonists; their secondary effects can alter perceived quality of life and increase the risk of adverse effects. Withdrawal of these drugs during hospital admission could increase the risk of delirium. Future research in this area should evaluate the management of hypnotics during hospital admission in patients with decompensated heart failure. In addition, safe and efficient non-pharmacological alternatives for the treatment of insomnia in this population should be tested and implemented.

Diagnostic accuracy and suitability of instruments that screen for obstructive sleep apnoea, insomnia and sleep quality in cardiac patients: a meta-analysis

BACKGROUND

A number of clinical guidelines recommend that all cardiac rehabilitation patients should be screened for potential sleep disorders with a validated screening instrument. There is currently no consensus on what specific tools should be used.

OBJECTIVE

To identify tools that are practical to use in the clinical environment and have high diagnostic accuracy.

METHODS

We systematically searched online databases to identify patient reported outcome instruments that have been used in published research studies to assess the likelihood of obstructive sleep apnoea (OSA) in cardiac patients. In studies that provided diagnostic data, these data were extracted and verified via an evidence-based diagnostic calculator. Where sufficient numbers of studies were available, a meta-analysis was conducted to determine pooled estimates of specificity, sensitivity and diagnostic odds ratios. Selected papers were qualitatively assessed using the Standards for Reporting Diagnostic accuracy studies (STARD).

RESULTS

Of the 21 instruments identified, six detected likelihood of OSA, two assessed daytime sleepiness, five assessed insomnia and eight examined sleep quality. A meta-analysis of 14 studies that assessed diagnostic accuracy of moderate OSA, revealed moderate sensitivity for the Berlin Questionnaire, Sens = 0.49 (95% CI 0.45-0.52) and good sensitivity for the Stop-BANG, Sens = 0.93 (95% CI 0.87-0.96) but poor specificity at standard cut-off criteria.

CONCLUSION

There are promising practical tools available to screen patients with OSA and other sleep disorders in cardiac rehabilitation settings, but specificity could be improved. Additional assessment of sleep quality may enhance prognostic ability with both OSA and insomnia screening.

Sleep Quality in Patients with Heart Failure in the Spanish Population: A Cross-Sectional Study

Background: Heart failure is a major problem in western societies. Sleep Disorders maintain a bidirectional relationship with heart failure, as shown by studies conducted in other countries. This study aims to describe the quality of sleep in Spanish patients with heart failure. Materials and methods: We carried out a cross-sectional study to analyze the quality of sleep in a sample of 203 patients with a diagnosis of heart failure admitted to an Internal Medicine Service. The Pittsburg Sleep Quality Index (PSQI) was used to evaluate sleep quality in our sample over a one-month period. Results: 75% of the sample presented sleep disorders. The most common problems included the interruption of sleep (73.5% nocturia and 30% breathing difficulties); 35% had poor sleep efficiency; 33% showed a decrease in daytime performance; 84% had used hypnotics at some point to induce sleep and 35% used them regularly. Conclusions: This is the first study to report on the perceived sleep quality of patients with heart failure in Spain. Self-perception of sleep quality differed from that estimated by the PSQI. The prevalence of the use of sleep-inducing medication was very high. The diurnal dysfunction generated by sleep disorders in a heart failure environment can contribute to the development of self-care and cognitive deterioration problems.

Zolpidem increases sleep efficiency and the respiratory arousal threshold without changing sleep apnoea severity and pharyngeal muscle activity

KEY POINTS

A decreased respiratory arousal threshold is one of the main contributors to obstructive sleep apnoea (OSA) pathogenesis. Several recent studies have sought to find a drug capable of increasing the respiratory arousal threshold without impairing pharyngeal muscle activity to reduce OSA severity, with variable success. Here we show that zolpidem increases the respiratory arousal threshold by ∼15%, an effect size which was insufficient to systematically decrease OSA severity as measured by the apnoea-hypopnoea index. Unlike recent physiological findings that showed paradoxical increases in pharyngeal muscle responsiveness during transient manipulations of airway pressure, zolpidem did not alter pharyngeal muscle responsiveness during natural sleep. It did, however, increase sleep efficiency without changing apnoea length, oxygen desaturation, next-day perceived sleepiness and alertness. These novel findings indicate that zolpidem was well tolerated and effective in promoting sleep in people with OSA, which may be therapeutically useful for people with OSA and comorbid insomnia.

ABSTRACT

A recent physiology study performed using continuous positive airway pressure (CPAP) manipulations indicated that the hypnotic zolpidem increases the arousal threshold and genioglossus responsiveness in people with and without obstructive sleep apnoea (OSA). Thus, zolpidem may stabilise breathing and reduce OSA severity without CPAP. Accordingly, we sought to determine the effects of zolpidem on OSA severity, upper airway physiology and next-day sleepiness and alertness. Nineteen people with OSA with low-to-moderate arousal threshold received 10 mg zolpidem or placebo according to a double-blind, randomised, cross-over design. Participants completed two overnight in-laboratory polysomnographies (1-week washout), with an epiglottic catheter, intramuscular genioglossus electromyography, nasal mask and pneumotachograph to measure OSA severity, arousal threshold and upper airway muscle responsiveness. Next-morning sleepiness and alertness were also assessed. Zolpidem did not change the apnoea-hypopnoea index versus placebo (40.6 ± 12.3 vs. 40.3 ± 16.4 events/h (means ± SD), p = 0.938) or nadir oxyhaemoglobin saturation (79.6 ± 6.6 vs. 79.7 ± 7.4%, p = 0.932), but was well tolerated. Zolpidem increased sleep efficiency by 9 ± 14% (83 ± 11 vs. 73 ± 17%, p = 0.010). Arousal threshold increased by 15 ± 5% with zolpidem throughout all sleep stages (p = 0.010), whereas genioglossus muscle responsiveness did not change. Next-morning sleepiness and alertness were not different between nights. In summary, a single night of 10 mg zolpidem is well tolerated and does not cause next-day impairment in alertness or sleepiness, or overnight hypoxaemia in OSA. However, despite increases in arousal threshold without any change in pharyngeal muscle responsiveness, zolpidem does not alter OSA severity. It does, however, increase sleep efficiency by ∼10%, which may be beneficial in people with OSA and insomnia.

Sleep Disturbances in Patients With Coronary Heart Disease: A Systematic Review

STUDY OBJECTIVES

Investigation into sleep and coronary heart disease (CHD) has predominantly been focused on sleep disturbances as a risk factor for developing CHD. Objectively measured and self-reported sleep at a patient level has only been sparsely and not systematically reported. Therefore, we set out to review the literature for studies using objectively measured and self-reported sleep in patients with CHD. The review focuses on patients with acute coronary syndrome (ACS) and stable CHD.

METHODS

A systematic review performed in four databases adhering to the PRISMA guidelines applying a qualitative synthesis of evidence.

RESULTS

Following ACS, we found sleep architecture to be significantly disturbed with changes normalizing over a period of up to 6 months. With increasing severity of CHD, sleep disturbances were more pronounced; however, the modulating effects of sleep-disordered breathing and ejection fraction on sleep in patients with CHD are conflicting. Overall, studies were predominantly cross-sectional in design and of low methodological quality. Polysomnography was the predominant outcome assessment tool and validated self-reported assessment tools were limited.

CONCLUSIONS

Future investigations in sleep and CHD applying both a longitudinal design and investigating objective and self-reported sleep assessments are warranted.

SYSTEMATIC REVIEW REGISTRATION

Registry: PROSPERO, Title: Sleep measures in relation to coronary heart disease: a systematic review, Identifier: CRD42017056377, URL: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=56377.

The effect of nonbenzodiazepines sedative hypnotics on apnea-hypopnea index: A meta-analysis

INTRODUCTION:

Nonbenzodiazepine (non-BZD) sedative hypnotics (NBSH) refer to non-BZD sedatives that act as BZD receptor agonists such as zolpidem, zaleplon, and eszopiclone. Today, there is a high prevalence of insomnia with or without concurrent obstructive sleep apnea (OSA). Our goal was to study how NBSH use impacts the baseline apnea–hypopnea index (AHI) in patients with or without OSA.

METHODS:

PubMed/MEDLINE, Scopus, Web of Science and Cochrane Library databases were searched.

RESULTS:

Seventeen studies comprising a cumulative total of 2099 patients were identified in the last 30 years (between 1988 and 2017) that evaluated the effect of NBSH on respiratory parameters during sleep. The AHI mean (M) ± standard deviation (SD) in NBSH group was 13.17 ± 16.27 versus 15.94 ± 19.31 (mean difference [MD]-95% confidence interval [CI], 2.77 [1.463–4.076]). Six studies (100 patients) compared zolpidem with either placebo or no medication and demonstrated an AHI MD of −0.61 events/h (95% CI − 1.94, 0.71), overall effect Z = 0.9, P = 0.36. Four studies (362 patients) compared eszopiclone with placebo and demonstrated an AHI MD of −5.73 events/h0 (95% CI − 8.90, −0.2.57). Two large studies (979 patients) compared both zolpidem and eszopiclone to no medication and found AHI MD of −1.66 events/h (95% CI − 5.87, 0.2.55).

CONCLUSIONS:

The majority of patients using NBSH did not develop any worsening of existing AHI, when using NBSH, regardless of their baseline AHI values (mild, moderate, severe, or no OSA). On average, the AHI improved minimally with NBSH and eszopiclone showed the largest difference in AHI with an MD of −5.73 events/h.