Opioid-Induced Central Sleep Apnea

Central sleep apnea: pathophysiologic classification

Central sleep apnea is not a single disorder; it can present as an isolated disorder or as a part of other clinical syndromes. In some conditions, such as heart failure, central apneic events are due to transient inhibition of ventilatory motor output during sleep, owing to the overlapping influences of sleep and hypocapnia. Specifically, the sleep state is associated with removal of wakefulness drive to breathe; thus, rendering ventilatory motor output dependent on the metabolic ventilatory control system, principally PaCO2. Accordingly, central apnea occurs when PaCO2 is reduced below the "apneic threshold". Our understanding of the pathophysiology of central sleep apnea has evolved appreciably over the past decade; accordingly, in disorders such as heart failure, central apnea is viewed as a form of breathing instability, manifesting as recurrent cycles of apnea/hypopnea, alternating with hyperpnea. In other words, ventilatory control operates as a negative-feedback closed-loop system to maintain homeostasis of blood gas tensions within a relatively narrow physiologic range, principally PaCO2. Therefore, many authors have adopted the engineering concept of "loop gain" (LG) as a measure of ventilatory instability and susceptibility to central apnea. Increased LG promotes breathing instabilities in a number of medical disorders. In some other conditions, such as with use of opioids, central apnea occurs due to inhibition of rhythm generation within the brainstem. This review will address the pathogenesis, pathophysiologic classification, and the multitude of clinical conditions that are associated with central apnea, and highlight areas of uncertainty.

Understanding and co-managing medication treatment options for opioid use disorder

The number of patients with opioid use disorder (OUD) has increased dramatically. Substance use disorders in general are thought to occur in one in five patients in primary care. However, despite this prevalence, there is a dearth of training in undergraduate and continuing medical education to manage OUDs, and internal medicine doctors need to have an understanding of the basic physiology and treatment options for this illness. Expanding knowledge of OUD treatments will allow internists to use their skills and strong patient-doctor relationships to ensure the trust of their patients with OUD, leading to better outcomes and increased chances of recovery. It will also allow clinicians to appropriately refer their patients for lifesaving specialized care and help them prevent dangerous medical complications often seen as a result of addiction. There are three FDA-approved medications to treat OUD disorder, known collectively as medication-assisted treatment (MAT). In this paper, the three medications-methadone, naltrexone, and buprenorphine-are presented, compared, contrasted, and clinically reviewed.

The effect of acetazolamide on the improvement of central apnea caused by abusing opioid drugs in the clinical trial

PURPOSE

Acetazolamide is utilized as a treatment which falls effective in treating some type of CSA. Hence, it might be effective as far as opium addicts who suffer from CSA are concerned.

MATERIALS AND METHOD

The current study was a double-blind, placebo-controlled, cross-over study ( clinicalTrials.gov ID: NCT02371473). The whole procedures were identical for both placebo and acetazolamide phases of clinical research. There were 14 CSA more than 5/h and more than 50% of apnea-hypopnea index (AHI). Out of these 14 patients, 10 volunteered to participate in the study. Fast Fourier transformation was used to separate heart rate variability (HRV) into its component VLF (very low frequency band), LF (low frequency band), and HF (high frequency band) rhythms that operate within different frequency ranges.

RESULT

There are significant results in terms of decreased mix apnea and central apnea together due to acetazolamide compared with placebo (P < 0.023). Time of SatO₂ < 90% is decreased as well (P < 0.1). There is also decrease of SDNN and NN50 after treatment with acetazolamide respectively (P < 0.001). Regarding fast Fourier transformation, there is increase of pHF and decrease of pLF after acetazolamide treatment (P < 0.001).

CONCLUSION

Acetazolamide seems to be effective in improving oxygenation and a decrease of mixed and central apnea events together. In HRV analysis section, LF power has decreased significantly, which may more likely improve prognosis of the patients.

Home Mechanical Ventilation: An Overview

Prevalence studies have shown heterogeneous use of home mechanical ventilation in different conditions, with a marked increase in uptake especially in users of noninvasive ventilation. Although randomized controlled trials have examined noninvasive ventilation in acute exacerbations of chronic obstructive pulmonary disease, for weaning from invasive ventilation and for postextubation respiratory failure, the evidence base for long-term noninvasive ventilation and comparisons with invasive ventilation are less well developed. The combination of noninvasive ventilation and cough-assist devices has reduced the indications for tracheotomy ventilation in some situations (e.g., Duchenne muscular dystrophy, spinal muscular atrophy, myopathies, and amyotrophic lateral sclerosis) and has also prolonged survival. Several excellent overviews have been written on the history of home mechanical ventilation and its evolution from negative pressure to positive pressure techniques, including a systematic review of outcomes. This review, instead, will cover recent trials, trends in the field, outcomes, and safety. Because the greatest growth has been in home noninvasive ventilation, this will be the main focus of this article.