Observational and retrospective studies suggest that people with narcolepsy may have an increased prevalence of cardiovascular and cardiometabolic comorbidities and may be at greater risk for future cardiovascular events. An expert consensus panel was formed to establish agreement on the risk of hypertension and cardiovascular/cardiometabolic disease in people with narcolepsy and to develop strategies to mitigate these risks.
This study reports polysomnographic features of five patients with Cheyne-Stokes respiration (CSR). They were referred for evaluation of presumptive sleep apnea syndrome on the basis of history and physical examination, but were found to have predominantly CSR on all-night sleep study. On the initial polysomnographic study, CSR comprised 47 to 86% of all disordered-breathing events. Cheyne-Stokes respiration resulted in considerable oxyhemoglobin desaturation (mean baseline saturation was 95 ± 4 ± SD, and lowest saturation was 76 ± 8). More than one-half of all CSR events resulted in awakenings or arousals. Evidence of upper airway obstruction was noted in the majority of CSR events in three of five patients. Four patients were treated with theophylline; one who refused drug therapy was treated with nasal continuous positive airway pressure (CPAP). Comparison of sleep studies before and after therapy showed a significant decrease in the CSR index (29 ± 11 versus 2 ± 2) and in the maximal oxyhemoglobin desaturation associated with CSR (13 ± 5 versus 3 ± 2), and an improvement in lowest O2 saturation associated with CSR (76 ± 8 versus 91 ± 4). Total disruptions in sleep architecture per hour of sleep improved significantly with therapy (46 ± 21 versus 20 ± 8). We conclude that the clinical presentation of CSR can be indistinguishable from that of the "traditional" sleep apnea hypopnea syndrome and can result in major oxyhemoglobin desaturation and sleep fragmentation. Theophylline results in considerable improvement in the disordered breathing of CSR during sleep.
Emphysema is known to progress in severity during the year after its induction by pancreatic elastase. A barometric chamber and indwelling aortic cannulas were used to evaluate the effects of worsening emphysema on pulmonary ventilation and arterial blood gases. Unanesthetized, unrestrained hamsters were studied 1, 5, and 13 months after panlobular emphysema was induced by intratracheal injection of porcine pancreatic elastase (0.2 mg in 0.5 ml of 0.15 M NaCl solution/100 g body weight). Lung volumes were subsequently measured in the anesthetized animals and the lungs were examined histologically and stereologically. The pattern of breathing in the 1-month emphysematous hamsters (n = 12) wsa the same as that of untreated control animals (n = 28) but the 5-month (n = 7) and 13-month (n = 6) animals breathed more deeply and slowly; there were no changes in mean inspiratory flow rate of proportion of time per breath occupied by inspiration. The PaO2 for all elastase-treated groups was significantly lower than the control but hypoxemia did not progress significantly with advancing age of the animals. The hematocrit was elevated for the 1-month and 5-month treated animals but not for the 13-month emphysematous animals. The arterial pH and PaCO2 values were not significantly different from control values in any of the three groups of emphysematous animals. We conclude that as hamsters with emphysema age their breathing becomes slower and deeper, that hypoxemia is present from 1 month onwards and does not progress and that hypercapnia is not found at any time.
PURPOSE: Chronic opioid use can disturb sleep architecture, cause sleep-disordered breathing including sleep-related hypoxemia, hypoventilation, Central Sleep Apnea (CSA), Obstructive Sleep Apnea (OSA), as well as ataxic breathing otherwise known as Biot's breathing.While CSA secondary to chronic opioid use is well-documented, there is limited data on the prevalence of diurnal and/or nocturnal hypercapnia in these patients.We aim to investigate the prevalence of diurnal and/or nocturnal hypercapnia and describe the correlation between the ventilatory derangements in patients with chronic opioid-induced CSA. METHODS:We conducted a retrospective observational study of adult patients (>18 years old) with chronic opioid-induced CSA who had a laboratory attended polysomnogram (PSG) with measured CO 2 (blood gas or transcutaneous CO 2 ).We used Pearson correlation coefficient to investigate the relationship between diurnal and nocturnal hypercarbia and evaluated the association between central apnea index (CAI) and measured CO 2 using linear regression (correlation coefficients).RESULTS: Among 163 patients with documented ICD-9 or ICD-10 code for CSA who were on chronic opioids (> 6 months) and had sleep studies, 43 patients met the inclusion criteria.Mean age was 42.99 AE 30.27 years, with 60.5% male.The mean morphine milligram equivalent (MME) the patients were using was 199.78AE283.Average transcutaneous CO 2 measured during PSG was 48 AE 7.69 mmHg, while the mean of pCO 2 in the blood gas was 44.89 AE 9.06 mmHg.There was no significant correlation between diurnal and nocturnal CO 2 (Pearson correlation: 0.177, P value ¼ 0.469).Diurnal and nocturnal hypercarbia had no correlation with the central sleep apnea index, with Pearson correlations of 0.93 (P value ¼ 0.618) for diurnal and 0.87 (P value ¼ 0.641) for nocturnal, respectively.CONCLUSIONS: This is the first study to describe the prevalence of diurnal and nocturnal hypercapnia in patients with opioidinduced CSA.Our study did not demonstrate a significant correlation between diurnal and nocturnal hypercarbia, but it highlights the prevalence of hypercarbia in this patient population.Our findings provide valuable information for understanding the respiratory status of patients with opioid-induced CSA and underscore the need for further studies characterizing the various presentations of sleep-related breathing disorders in this population.CLINICAL IMPLICATIONS: Our study enhances understanding of CO 2 parameters in patients with opioid-induced CSA and provides insight for future research aimed at understanding and characterizing respiratory characteristics in patients on chronic use of opioids.
