Kannan Ramar

The treatment of central sleep apnea syndromes in adults: practice parameters with an evidence-based literature review and meta-analyses.

The International Classification of Sleep Disorders, Second Edition (ICSD-2) distinguishes 5 subtypes of central sleep apnea syndromes (CSAS) in adults. Review of the literature suggests that there are two basic mechanisms that trigger central respiratory events: (1) post-hyperventilation central apnea, which may be triggered by a variety of clinical conditions, and (2) central apnea secondary to hypoventilation, which has been described with opioid use. The preponderance of evidence on the treatment of CSAS supports the use of continuous positive airway pressure (CPAP). Much of the evidence comes from investigations on CSAS related to congestive heart failure (CHF), but other subtypes of CSAS appear to respond to CPAP as well. Limited evidence is available to support alternative therapies in CSAS subtypes. The recommendations for treatment of CSAS are summarized as follows: CPAP therapy targeted to normalize the apnea-hypopnea index (AHI) is indicated for the initial treatment of CSAS related to CHF. (STANDARD)Nocturnal oxygen therapy is indicated for the treatment of CSAS related to CHF. (STANDARD)Adaptive Servo-Ventilation (ASV) targeted to normalize the apnea-hypopnea index (AHI) is indicated for the treatment of CSAS related to CHF. (STANDARD)BPAP therapy in a spontaneous timed (ST) mode targeted to normalize the apnea-hypopnea index (AHI) may be considered for the treatment of CSAS related to CHF only if there is no response to adequate trials of CPAP, ASV, and oxygen therapies. (OPTION)The following therapies have limited supporting evidence but may be considered for the treatment of CSAS related to CHF after optimization of standard medical therapy, if PAP therapy is not tolerated, and if accompanied by close clinical follow-up: acetazolamide and theophylline. (OPTION)Positive airway pressure therapy may be considered for the treatment of primary CSAS. (OPTION)Acetazolamide has limited supporting evidence but may be considered for the treatment of primary CSAS. (OPTION)The use of zolpidem and triazolam may be considered for the treatment of primary CSAS only if the patient does not have underlying risk factors for respiratory depression. (OPTION)The following possible treatment options for CSAS related to end-stage renal disease may be considered: CPAP, supplemental oxygen, bicarbonate buffer use during dialysis, and nocturnal dialysis. (OPTION) .

Updates on Definition, Consequences, and Management of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a breathing disorder during sleep that has implications beyond disrupted sleep. It is increasingly recognized as an independent risk factor for cardiac, neurologic, and perioperative morbidities. Yet this disorder remains undiagnosed in a substantial portion of our population. It is imperative for all physicians to remain vigilant in identifying patients with signs and symptoms consistent with OSA. This review focuses on updates in the areas of terminology and testing, complications of untreated OSA, perioperative considerations, treatment options, and new developments in this field.

Clinical practice guideline for the treatment of obstructive sleep apnea and snoring with oral appliance therapy: An update for 2015

INTRODUCTION Since the previous parameter and review paper publication on oral appliances (OAs) in 2006, the relevant scientific literature has grown considerably, particularly in relation to clinical outcomes. The purpose of this new guideline is to replace the previous and update recommendations for the use of OAs in the treatment of obstructive sleep apnea (OSA) and snoring. METHODS The American Academy of Sleep Medicine (AASM) and American Academy of Dental Sleep Medicine (AADSM) commissioned a seven-member task force. A systematic review of the literature was performed and a modified Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the quality of evidence. The task force developed recommendations and assigned strengths based on the quality of the evidence counterbalanced by an assessment of the relative benefit of the treatment versus the potential harms. The AASM and AADSM Board of Directors approved the final guideline recommendations. RECOMMENDATIONS 1. We recommend that sleep physicians prescribe oral appliances, rather than no therapy, for adult patients who request treatment of primary snoring (without obstructive sleep apnea). (STANDARD) 2. When oral appliance therapy is prescribed by a sleep physician for an adult patient with obstructive sleep apnea, we suggest that a qualified dentist use a custom, titratable appliance over non-custom oral devices. (GUIDELINE) 3. We recommend that sleep physicians consider prescription of oral appliances, rather than no treatment, for adult patients with obstructive sleep apnea who are intolerant of CPAP therapy or prefer alternate therapy. (STANDARD) 4. We suggest that qualified dentists provide oversight—rather than no follow-up—of oral appliance therapy in adult patients with obstructive sleep apnea, to survey for dental-related side effects or occlusal changes and reduce their incidence. (GUIDELINE) 5. We suggest that sleep physicians conduct follow-up sleep testing to improve or confirm treatment efficacy, rather than conduct follow-up without sleep testing, for patients fitted with oral appliances. (GUIDELINE) 6. We suggest that sleep physicians and qualified dentists instruct adult patients treated with oral appliances for obstructive sleep apnea to return for periodic office visits—as opposed to no follow-up—with a qualified dentist and a sleep physician. (GUIDELINE). CONCLUSIONS The AASM and AADSM expect these guidelines to have a positive impact on professional behavior, patient outcomes, and, possibly, health care costs. This guideline reflects the state of knowledge at the time of publication and will require updates if new evidence warrants significant changes to the current recommendations.

Sleep Deprivation in Resident Physicians, Work Hour Limitations, and Related Outcomes: A Systematic Review of the Literature

Abstract Extended work hours, interrupted sleep, and shift work are integral parts of medical training among all specialties. The need for 24-hour patient care coverage and economic factors have resulted in prolonged work hours for resident physicians. This has traditionally been thought to enhance medical educational experience. These long and erratic work hours lead to acute and chronic sleep deprivation and poor sleep quality, resulting in numerous adverse consequences. Impairments may occur in several domains, including attention, cognition, motor skills, and mood. Resident performance, professionalism, safety, and well–being are affected by sleep deprivation, causing potentially adverse implications for patient care. Studies have shown adverse health consequences, motor vehicle accidents, increased alcohol and medication use, and serious medical errors to occur in association with both sleep deprivation and shift work. Resident work hour limitations have been mandated by the Accreditation Council for Graduate Medical Education in response to patient safety concerns. Studies evaluating the impact of these regulations on resident physicians have generated conflicting reports on patient outcomes, demonstrating only a modest increase in sleep duration for resident physicians, along with negative perceptions regarding their education. This literature review summarizes research on the effects of sleep deprivation and shift work, and examines current literature on the impact of recent work hour limitations on resident physicians and patient–related outcomes.

Uvulopalatopharyngoplasty in the Management of Obstructive Sleep Apnea: The Mayo Clinic Experience

OBJECTIVE To assess the role of uvulopalatopharyngoplasty (UPPP) in the treatment of obstructive sleep apnea (OSA) using polysomnography (PSG) data within 6 months before and after surgery. PATIENTS AND METHODS We analyzed PSG and body mass index (BMI) data from patients with OSA who were 18 years or older and who underwent UPPP between January 1, 1988, and August 31, 2006. RESULTS Sixty-three patients (51 men [81.0%]; mean ± SD age, 42.1±13.9 years; mean ± SD BMI, 34.9±7.2) underwent PSG a mean ± SD of 50±47 days before and 88.5±34.0 days after UPPP. Surgical cure was defined as a postoperative apnea-hypopnea index (AHI) of 5 or less. Fifteen patients (24%) achieved a surgical cure. Twenty-one patients (33%) had a postoperative AHI of 10 or less, whereas 32 (51%) achieved a 50% or greater reduction in AHI and/or an AHI of 20 or less. No significant changes were noted in BMI before and 6 months after UPPP. Patients who attained an AHI of 5 or less were younger (mean ± SD age, 35.9±13.1 vs 44±13.7 years; P =.05), had lower BMIs (mean ± SD, 30.8±6.5 vs 34.6±6.6; P =.05), and had less severe OSA (mean ± SD AHI, 38.1±33.6 vs 69.6±32.8; P =.004). Of the 48 patients (76%) with a post-UPPP AHI greater than 5, 35 (56%) received continuous positive airway pressure, with a mean reduction in pressure of 1.4 cm H 2 O (95% confidence interval, -0.4 to -2.4 cm H 2 O). CONCLUSION Independent of changes in BMI, in our retrospective analysis, UPPP achieved an AHI of 5 or less in 24% and an AHI of 10 or less in 33% of patients with OSA who underwent PSG 6 months before and after surgery. In those with residual OSA who received continuous positive airway pressure, the required pressure setting decreased by 1.4 cm H 2 O.

Effect of obstructive sleep apnea on type 2 diabetes mellitus: A comprehensive literature review.

Obstructive sleep apnea (OSA) is frequently associated with obesity and metabolic syndrome. Also frequently associated with metabolic syndrome is type 2 diabetes mellitus (T2DM). Therefore, it is common to find OSA and T2DM together in individuals with metabolic syndrome. Additionally, both OSA and T2DM have a common pathophysiological link with development of insulin resistance. Individuals with severe insulin resistance are likely to have inadequate glycemic control. Long standing poorly controlled T2DM is associated with debilitating microvascular complications such as retinopathy, nephropathy, neuropathy and macrovascular complications such as coronary artery and cerebrovascular disease. There is extensively published literature exploring the cause-effect relationship between OSA and T2DM. In this article we provide an in-depth review of the complex pathophysiological mechanisms linking OSA to T2DM. Specifically, this review focusses on the effect of OSA on the microvascular complications of T2DM such as retinopathy, nephropathy and neuropathy. Additionally, we review the current literature on the effect of continuous positive airway pressure use in individuals with T2DM and OSA.

Adaptive servoventilation in patients with central or complex sleep apnea related to chronic opioid use and congestive heart failure

STUDY OBJECTIVES Adaptive servoventilation (ASV) is often used to treat central sleep apnea (CSA) and complex sleep apnea syndrome (CompSAS). Both CompSAS and CSA may occur in the setting of CHF and with the use of chronic opioids. We hypothesized that ASV would be less successful in treatment of CSA and CompSAS secondary to opioid use than in CHF patients. METHODS Consecutive patients were studied between January and December 2009 who underwent ASV titration for CSA or CompSAS due to CHF (defined as EF < 45%, or > 50% with evidence for diastolic dysfunction on echocardiogram) and chronic opioid users (defined by the use of opioids > 6 months). RESULTS Study included one hundred and eight patients with 77 males (71.3%) and 31 females (28.7%). Subjects had severe sleep apnea at baseline (AHI 45.6 ± 27.4) and inadequate control of sleep disordered breathing on CPAP (AHI 50.0 ± 32.2, CAI 36.6 ± 32). No significant differences were found between the groups in overall ASV success, defined as AHI < 10/h (p = 0.236). ASV was successful in 28 (59.6%) of those in the opioid group, compared to 43 (70.5%) of those in the CHF group. When ASV success was defined as AHI < 5/h at optimum EEP, there was again no significant difference between the groups (p-value = 0.812). Logistic regression showed unit increases in BMI, unit increases in HCO(3), and presence of CSR were each associated with decreased likelihood of ASV success. CONCLUSION We did not find a statistically significant difference in the effectiveness of ASV between CHF patients and chronic opioid users, with the overall success rate approaching 70%, as defined by an AHI < 10/h. COMMENTARY A commentary on this article appears in this issue on page 577.

Increased fluid administration in the first three hours of sepsis resuscitation is associated with reduced mortality: a retrospective cohort study.

BACKGROUND The surviving sepsis guidelines recommend early aggressive fluid resuscitation within 6 h of sepsis onset. Although rapid fluid administration may offer benefit, studies on the timing of resuscitation are lacking. We hypothesized that there is an association between quicker, adequate fluid resuscitation and patient outcome from sepsis onset time. METHODS This is a retrospective cohort study of consecutive adults with severe sepsis and septic shock admitted to a quaternary care medical ICU between January 2007 and December 2009. Data were collected from a previously validated electronic medical database. Multivariate regression modeling was performed, adjusting for age, admission weight, Sequential Organ Failure Assessment score, APACHE (Acute Physiology and Chronic Health Examination) III score, and total fluid administration within the first 6 h of sepsis onset time. RESULTS Of 651 patients with severe sepsis and septic shock screened, 594 had detailed fluid data. In a univariate analysis, the median amount of fluid within the first 3 h for survivors at discharge was 2,085 mL (940-4,080 mL) and for nonsurvivors, 1,600 mL (600-3,010 mL; P = .007). In comparison, during the latter 3 h, the median amount was 660 mL (290-1,485 mL) vs 800 mL (360-1,680 mL; P = .09), respectively. After adjusting for confounders, the higher proportion of total fluid received within the first 3 h was associated with decreased hospital mortality (OR, 0.34; 95% CI, 0.15-0.75; P = .008). CONCLUSIONS Earlier fluid resuscitation (within the first 3 h) is associated with a greater number of survivors with severe sepsis and septic shock.

Reversal of Sleep-Disordered Breathing with Opioid Withdrawal

Obstructive sleep apnea, central sleep apnea, sleep related hypoventilation, Biots or ataxic breathing, and cluster breathing are some of the commonly described sleep disorders in patients who are on long‐term opioids. Continuous positive airway pressure that is commonly used to treat obstructive sleep apnea may not be effective in treating sleep‐disordered breathing in long‐term opioid users, and an adaptive servoventilator (ASV) may be needed. We present a 30‐year‐old woman with excessive daytime sleepiness and sleep‐disordered breathing for the past 4 years. Medical history was complicated by chronic osteomyelitis, periorbital abscess, and chronic facial pain requiring methadone for pain control for the last 4 years. In this case, ASV, though effective, was not tolerable due to chronic facial pain, and successful withdrawal of methadone at our pain rehabilitation center resolved the sleep‐disordered breathing and improved daytime sleepiness. This is to our knowledge the first case report of resolution of sleep‐disordered breathing and improvement in daytime sleepiness after withdrawal of long‐term opioid use.

Vascular changes, cardiovascular disease and obstructive sleep apnea

Vascular changes related to obstructive sleep apnea (OSA) can lead to chronic cardiovascular consequences such as hypertension. The cardiovascular consequences are owing to nocturnal perturbations related to intrathoracic pressure changes, intermittent hypoxia, sympathetic neural activation, endothelial dysfunction, oxidative stress and systemic inflammation. Intermittent hypoxia due to sleep-related events in OSA activates the renin-angiotensin system and increases the levels of endothelin-1. Intermittent hypoxia also results in oxidative stress, as evidenced by elevated levels of xanthine oxidoreductase, lipid peroxidation and the presence of reactive oxygen species. There is also evidence for a decrease in antioxidant capacity. Patients with OSA may have endothelial dysfunction that resolves with continuous positive airway pressure. OSA is a state of inflammation as evidenced by elevated levels of C-reactive protein, IL-6, NF-κB, TNF-α, ICAM-1, VCAM-1 and E-selectin. This may suggest that OSA is a predisposing factor for atherogenesis. This article will discuss the role of nocturnal perturbations consequent to OSA resulting in endothelial dysfunction, oxidative stress, and inflammation and how they may subsequently play a causative role in cardiovascular disorders.