Noninvasive volume-assured pressure support for chronic respiratory failure: a review.

PURPOSE OF REVIEW: Noninvasive ventilation (NIV) is an established treatment for chronic hypercapnic respiratory failure (CRF). Volume-assured pressure support (VAPS) is a mode of NIV that automatically adjusts inspiratory pressure in order to maintain a constant respiratory volume. We aim to discuss the role and application of VAPS in CRF. RECENT FINDINGS: Recently published meta-analyses and reviews fail to demonstrate a significant difference in gas exchange, sleep, or quality-of-life improvement between VAPS and bilevel positive airway pressure (BPAP) in patients with CRF. A recent manuscript suggests that VAPS therapy in chronic obstructive pulmonary disease patients may reduce the number of exacerbations. It has been shown that with a protocol-driven approach BPAP and VAPS can both be successfully titrated during a single split-night polysomnography. SUMMARY: VAPS is as effective as other modes of NIV at improving ventilation and sleep in CRF. The potential advantage is a more consistent ventilatory support through daytime-nighttime variations and progression of disease over time. However, the impact on long-term outcomes, such as survival, has not been studied.

The sawtooth sign is predictive of obstructive sleep apnea.

BACKGROUND: The sawtooth sign in spirometry is associated with redundant upper airway tissue and snoring, but its predictive value for identifying obstructive sleep apnea (OSA) is disputed. We retrospectively assessed the predictive value of the spirometric sawtooth sign in terms of the odds ratio (OR) of association with a diagnosis of OSA compared to those without the sign. METHODS: Consecutive spirometry reports showing a sawtooth sign were identified from our laboratory. We identified 50 subjects with sawtooth sign and 100 control subjects without sawtooth sign, matched for age, BMI, and gender. The electronic medical record of each patient was queried for a diagnosis of OSA based on physician-reported diagnoses. RESULTS: Of the 50 subjects with sawtooth sign, 22 were found to have a current diagnosis of OSA (44%). Twenty-seven of the 100 controls (27%) also had OSA. From logistic regression analysis, sawtooth sign was associated with an increased likelihood of OSA (OR = 2.12, 95% C.I. 1.04 to 4.35). Similar results were obtained after adjustment for age, gender, pack years, and BMI (OR = 2.61, 95% C.I. 1.13 to 6.21). CONCLUSIONS: Patients with the sawtooth sign have greater odds of having a diagnosis of OSA compared with those without the sign. If prospectively evaluated, as a result of improved identification, we hypothesize that the sawtooth sign may show an even stronger association with OSA. This relatively common finding, which adds no cost to routine spirometry, may serve as an indicator for OSA workup for some individuals not already identified as having OSA.

Hydrogen-limited growth of hyperthermophilic methanogens at deep-sea hydrothermal vents.

Microbial productivity at hydrothermal vents is among the highest found anywhere in the deep ocean, but constraints on microbial growth and metabolism at vents are lacking. We used a combination of cultivation, molecular, and geochemical tools to verify pure culture H(2) threshold measurements for hyperthermophilic methanogenesis in low-temperature hydrothermal fluids from Axial Volcano and Endeavour Segment in the northeastern Pacific Ocean. Two Methanocaldococcus strains from Axial and Methanocaldococcus jannaschii showed similar Monod growth kinetics when grown in a bioreactor at varying H(2) concentrations. Their H(2) half-saturation value was 66 µM, and growth ceased below 17-23 µM H(2), 10-fold lower than previously predicted. By comparison, measured H(2) and CH(4) concentrations in fluids suggest that there was generally sufficient H(2) for Methanocaldococcus growth at Axial but not at Endeavour. Fluids from one vent at Axial (Marker 113) had anomalously high CH(4) concentrations and contained various thermal classes of methanogens based on cultivation and mcrA/mrtA analyses. At Endeavour, methanogens were largely undetectable in fluid samples based on cultivation and molecular screens, although abundances of hyperthermophilic heterotrophs were relatively high. Where present, Methanocaldococcus genes were the predominant mcrA/mrtA sequences recovered and comprised ∼0.2-6% of the total archaeal community. Field and coculture data suggest that H(2) limitation may be partly ameliorated by H(2) syntrophy with hyperthermophilic heterotrophs. These data support our estimated H(2) threshold for hyperthermophilic methanogenesis at vents and highlight the need for coupled laboratory and field measurements to constrain microbial distribution and biogeochemical impacts in the deep sea.

Middle ear pressure during sleep and the effects of continuous positive airway pressure.

PURPOSE: Prior studies evaluating Eustachian tube physiology, baseline middle ear pressure (MEP), and the effects of continuous positive airway pressure (CPAP) have been performed on awake patients. No study to date has specifically investigated MEP during sleep despite the fact that the average individual spends a third of their lifetime sleeping. The primary objectives of the current study are to quantify normal physiologic MEP during sleep and to evaluate the effects of escalating CPAP levels. MATERIALS AND METHODS: Prospective observational study at a tertiary academic referral center evaluating serial tympanometry on sleeping adult patients during polysomnography. MEP was recorded awake, at 1-hour intervals during diagnostic polysomnography, and at all CPAP levels during titration. Changes in MEP with duration of sleep and escalating CPAP levels were analyzed. RESULTS: Ten adults were included (4 females; 6 males; mean age 58years). The mean MEP while awake was 3 decapascals (daPa). The mean MEP during sleep without CPAP rose steadily from 14 daPa at 1hour to 41 daPa at 4hours (r=0.52; p<0.001). The mean MEP during sleep at a CPAP level of 5cm of water was 54 daPa. The mean MEP rose steadily with increasing CPAP levels, and was 104 daPa at 10cm of water, (r=0.82; p<0.001). The mean MEP during sleep without CPAP was 26 daPa, which was significantly lower than the mean MEP during sleep with CPAP between 5-10cm H2O (p<0.01). CONCLUSIONS: MEP naturally increases with duration of sleep. CPAP therapy causes a supraphysiologic elevation in MEP that rises with increasing pressure levels. These findings may help guide future studies examining the safety of CPAP following otologic surgery and the potential therapeutic benefit in patients with chronic middle ear disease.

Recommendations for permanent sleep telehealth: an American Academy of Sleep Medicine position statement.

Telehealth use greatly expanded under the Centers for Medicare and Medicaid Services (CMS) waivers at the start of the COVID-19 pandemic; however, the uncertainty and limitations of continued coverage risks loss of this momentum. Permanent coverage with adequate reimbursement is essential for the long-term acceptance and expansion of telehealth services. Telehealth supports both the current and future need for sleep health management by expanding patient access, increasing clinician efficiency, improving patient safety, and addressing health care equity. Sleep medicine is an ideal field for telehealth due to limited provider access, safety concerns with sleepy patients, availability of remote patient monitoring for treatment management, and the minimal need for repeated physical examinations. Telehealth is non-inferior for delivery of cognitive behavioral therapy for insomnia (CBT-I) and can enhance obstructive sleep apnea (OSA) treatment adherence. It is the position of the American Academy of Sleep Medicine (AASM) that telehealth is an essential tool for the provision of high quality, patient-centered care for patients with sleep disorders. We encourage all stakeholders including legislators, policymakers, clinicians, and patients to work together to address payment models, interstate care, technology access, prescribing practices, and ongoing research to ensure that sleep telehealth services are permanently available and accessible for all patients seeking sleep medicine care.

Phenoconversion in Women and Men With Isolated REM Sleep Behavior Disorder: A Retrospective Cohort Study.

BACKGROUND AND OBJECTIVES: Isolated REM sleep behavior disorder (iRBD) is strongly associated with synucleinopathies. Previous iRBD cohort studies have primarily focused on older (>50 years), male-predominant cohorts. Risk of phenoconversion in women and younger adults remains unclear. The study aimed to determine clinical features associated with conversion to a defined neurodegenerative disorder in women and men with iRBD. METHODS: One hundred eighty-six women and 186 men with iRBD were matched by polysomnography month. Baseline clinical variables and subsequent neurodegenerative outcomes were abstracted by chart review. Kaplan-Meier curves assessed conversion rates. Cox proportional hazards modeling evaluated factors associated with phenoconversion risk. RESULTS: Age at iRBD diagnosis was younger in women compared with men (54.9 vs 62.5 years, p < 0.01). Forty-eight patients (12.9%), including 18 women (9.7%) and 30 men (16.1%), phenoconverted during a median follow-up of 6.0 years. Conversion rates were lower in antidepressant users and patients with chronic pain or psychiatric comorbidity while rates were higher in those with vascular comorbidity. Only age at diagnosis (HR 1.09, 95% CI 1.06-1.13) was associated with phenoconversion after adjusting for RBD symptom duration; sex; antidepressant use; and psychiatric, chronic pain, and vascular comorbidities. DISCUSSION: Age at diagnosis was independently associated with phenoconversion risk in women and men with iRBD.

Lipid effects of peroxisome proliferator-activated receptor-δ agonist GW501516 in subjects with low high-density lipoprotein cholesterol: characteristics of metabolic syndrome.

OBJECTIVE: Peroxisome proliferator-activated receptor-δ-induced upregulation in skeletal muscle fatty acid oxidation would predict the modulation of lipid/lipoproteins. METHODS AND RESULTS: GW501516 (2.5, 5.0, or 10.0 mg) or placebo was given for 12 weeks to patients (n=268) with high-density lipoprotein (HDL) cholesterol <1.16 mmol/L. Fasting lipids/apolipoproteins (apos), insulin, glucose, and free fatty acid were measured; changes from baseline were calculated and assessed. A second smaller exploratory study (n=37) in a similar population was conducted using a sequence of 5 and 10 mg dosing for the assessment of lipoprotein particle concentration. GW501516 demonstrated HDL cholesterol increases up to 16.9% (10 mg) and apoA-I increases up to 6.6%. Reductions were observed in low-density lipoprotein (LDL) cholesterol (-7.3%), triglycerides (-16.9%), apoB (-14.9%), and free fatty acids (-19.4%). The exploratory study showed significant reductions in the concentration of very LDL (-19%), intermediate-density lipoprotein (-52%), and LDL (-14%, predominantly a reduction in small particles), whereas the number of HDL particles increased (+10%; predominantly medium and large HDL). CONCLUSIONS: GW501516 produced significant changes in HDL cholesterol, LDL cholesterol, apoA1, and apoB. Fewer very LDL and larger LDL support a transition toward less atherogenic lipoprotein profiles. These data are consistent with peroxisome proliferator-activated receptor-δ being a potentially important target for providing cardiovascular protection in metabolic syndrome-like patients.

Management of common sleep disorders.

Sleep disorders are common and affect sleep quality and quantity, leading to increased morbidity. Patients with sleep disorders can be categorized as those who cannot sleep, those who will not sleep, those with excessive daytime sleepiness, and those with increased movements during sleep. Insomnia, defined as difficulty initiating or maintaining sleep that results in daytime impairment, is diagnosed using history findings and treated with cognitive behavior therapy, with or without sleep hypnotics. Restless legs syndrome is characterized by an urge to move the legs that worsens with rest, is relieved by movement, and often occurs in the evening or at night. Restless legs syndrome is treated based on the frequency of symptoms. Narcolepsy is characterized by excessive sleepiness, cataplexy, hypnagogic or hypnopompic hallucinations, and sleep paralysis. It is diagnosed using a sleep log or actigraphy, followed by overnight polysomnography and a multiple sleep latency test. Narcolepsy is treated with stimulants, such as modafinil; selective serotonin reuptake inhibitors; or gamma hydroxybutyric acid (sodium oxybate). Patients with snoring and witnessed apneas may have obstructive sleep apnea, which is diagnosed using overnight polysomnography. Continuous positive airway pressure is the most common and effective treatment for obstructive sleep apnea. Rapid eye movement sleep behavior disorder is characterized by increased muscle tone during rapid eye movement sleep, resulting in the patient acting out dreams with possible harmful consequences. It is diagnosed based on history and polysomnography findings, and treated with environmental safety measures and melatonin or clonazepam.

Sex-specific associations between daytime sleepiness, chronic diseases and mortality in obstructive sleep apnea.

Objective: Excessive daytime sleepiness (EDS) is common in obstructive sleep apnea (OSA) and has been linked to adverse outcomes, albeit inconsistently. Furthermore, whether the prognostic impact of EDS differs as a function of sex is unclear. We aimed to assess the associations between EDS and chronic diseases and mortality in men and women with OSA. Methods: Newly-diagnosed adult OSA patients who underwent sleep evaluation at Mayo Clinic between November 2009 and April 2017 and completed the Epworth Sleepiness Scale (ESS) for assessment of perceived sleepiness (N = 14,823) were included. Multivariable-adjusted regression models were used to investigate the relationships between sleepiness, with ESS modeled as a binary (ESS > 10) and as a continuous variable, and chronic diseases and all-cause mortality. Results: In cross-sectional analysis, ESS > 10 was independently associated with lower risk of hypertension in male OSA patients (odds ratio [OR], 95% confidence interval [CI]: 0.76, 0.69-0.83) and with higher risk of diabetes mellitus in both OSA men (OR, 1.17, 95% CI 1.05-1.31) and women (OR 1.26, 95% CI 1.10-1.45). Sex-specific curvilinear relations between ESS score and depression and cancer were noted. After a median 6.2 (4.5-8.1) years of follow-up, the hazard ratio for all-cause death in OSA women with ESS > 10 compared to those with ESS ≤ 10 was 1.24 (95% CI 1.05-1.47), after adjusting for demographics, sleep characteristics and comorbidities at baseline. In men, sleepiness was not associated with mortality. Conclusion: The implications of EDS for morbidity and mortality risk in OSA are sex-dependent, with hypersomnolence being independently associated with greater vulnerability to premature death only in female patients. Efforts to mitigate mortality risk and restore daytime vigilance in women with OSA should be prioritized.

Snoring is associated with unexpected patient head movement during monitored anesthesia care vitreoretinal surgery.

PURPOSE: To assess whether snoring is associated with sudden patient movement during local anesthesia with intravenous sedation. METHODS: In this prospective cohort study, patients undergoing ocular surgery with local anesthesia with intravenous sedation were studied. The occurrence or absence of snoring, and whether patient movement was noted were prospectively recorded. Complications that arose from patient movement were also noted. RESULTS: A total of 230 surgical procedures were included in the study. All cases were vitreoretinal surgery cases. During 37 procedures, snoring was noted, and among these, 18 patients (48.6%) moved their head suddenly. In contrast, movement occurred during only 2 of 193 procedures (1.0%) without documented snoring (P < 0.001). Thus, sudden patient head movement was approximately 49 times more prevalent in patients who snored. Continuous infusion propofol was also associated with sudden unexpected head movement (P = 0.0028). No complications as a result of the movement were identified in this study. CONCLUSION: Snoring during local anesthesia with intravenous sedation predicts a high likelihood of sudden patient movement during local anesthesia with intravenous sedation. The use of continuous infusion propofol anesthetic may increase the chance of head movement. Eye surgeons should be aware of these associations to help minimize the risk of complications caused by patient movement.

Nocturnal moaning and groaning-catathrenia or nocturnal vocalizations.

PURPOSE: Descriptions of nocturnal vocalizations, including catathrenia, are few. We undertook a study at our center on patients diagnosed with catathrenia, to evaluate the characteristic features of these events and their response to continuous positive airway pressure (CPAP) treatment. METHODS: Retrospective study of patients with a diagnosis of catathrenia who had an overnight polysomnogram (PSG) and available synchronized audio video recordings (to confirm the presence of moaning and groaning), at our center between January 2007 and May 2010. RESULT: Ten patients were included in the analysis. Three (30%) patients presented with the chief complaint of expiratory noises during sleep. The other moaning/groaning sounds were incidental findings noted by the sleep technologist and/or the sleep physician. The number of moaning/groaning events during PSG varied between 2 and 343 per patient with sound duration ranging from 0.4 to 21.4 s. Moaning/groaning events during exhalation (1,026 episodes) were separated into typical catathrenia events (as per the International Classification of Sleep Disorders, 2nd edition [ICSD-2] definition) and atypical/nocturnal vocalization events (moaning/groaning events that did not meet the ICSD-2 criteria). Typical catathrenia events (5% or 52/1,026) were experienced by five of the ten patients and had mean exhalation duration of 14.97 ± 5.13 s (range 5.8-24 s) with a mean sound duration of 8.47 ± 5.97 s (range 2-21.4 s). The typical and atypical events occurred predominantly in NREM sleep. Six of the ten patients had associated sleep-disordered breathing and four underwent CPAP titration. All four patients had significantly fewer events of moaning/groaning (mean reduction was 75.8 ± 26.2%) with CPAP. CONCLUSION: New and unique features were identified in our series of patients diagnosed with catathrenia. Though all events had the characteristic moaning and groaning sound during exhalation, only a small percentage (5%) met the catathrenia definition as outlined in ICSD-2. Do we label the atypical events as part of the spectrum of nocturnal vocalizations or consider them as catathrenia by redefining the criteria? CPAP appeared to be a reasonable treatment option.

Age and weight considerations for the use of continuous positive airway pressure therapy in pediatric populations: an American Academy of Sleep Medicine position statement.

This position statement provides guidance for age and weight considerations for using continuous positive airway pressure therapy in pediatric populations. The American Academy of Sleep Medicine commissioned a task force of experts in pediatric sleep medicine to review the medical literature and develop a position statement based on a thorough review of these studies and their clinical expertise. The American Academy of Sleep Medicine Board of Directors approved the final position statement. It is the position of the American Academy of Sleep Medicine that continuous positive airway pressure can be safe and effective for the treatment of obstructive sleep apnea for pediatric patients, even in children of younger ages and lower weights, when managed by a clinician with expertise in evaluating and treating pediatric obstructive sleep apnea. The clinician must make the ultimate judgment regarding any specific care in light of the individual circumstances presented by the patient, accessible treatment options, patient/parental preference, and resources. CITATION: Amos L, Afolabi-Brown O, Gault D, et al. Age and weight considerations for the use of continuous positive airway pressure therapy in pediatric populations: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2022;18(8):2041-2043.

Enhancing public health and safety by diagnosing and treating obstructive sleep apnea in the transportation industry: an American Academy of Sleep Medicine position statement.

Obstructive sleep apnea (OSA) may lead to serious health, safety, and financial implications-including sleepiness-related crashes and incidents-in workers who perform safety-sensitive functions in the transportation industry. Evidence and expert consensus support its identification and treatment in high-risk commercial operators. An Advanced Notice of Proposed Rulemaking regarding the diagnosis and treatment of OSA in commercial truck and rail operators was issued by the Federal Motor Carrier Safety Administration and Federal Railroad Administration, but it was later withdrawn. This reversal has led to questions about whether efforts to identify and treat OSA are warranted. In the absence of clear directives, we urge key stakeholders, including clinicians and patients, to engage in a collaborative approach to address OSA by following, at a minimum, the 2016 guidelines issued by a Medical Review Board of the Federal Motor Carrier Safety Administration, alone or in combination with 2006 guidance by a joint task force. The current standard of care demands action to mitigate the serious health and safety risks of OSA. CITATION: Das AM, Chang JL, Berneking M, et al. Enhancing public health and safety by diagnosing and treating obstructive sleep apnea in the transportation industry: an American Academy of Sleep Medicine position statement. J Clin Sleep Med. 2022;18(10):2467-2470.

Interaction of a weakly acidic dinitroaromatic with alkylamines: avoiding the Meisenheimer trap.

Polynitroaromatics are well-known to form anionic σ-complexes (Meisenheimer complexes). The formation of such complexes was assumed in the past to explain the blue color of solutions of 2,4-dinitrotoluene (DNT) and amines. However, this work shows that caution is warranted to avoid the hasty misidentification of Meisenheimer complexes. (1)H NMR spectra exhibit no significant shifts in the positions of the DNT protons, indicating that the majority of DNT species in solutions of DNT and amines retain their aromaticity. Density functional calculations on DNT-ethylamine complexes suggest that Meisenheimer complexes are sufficiently high in free energy so that they make up only a very small fraction of the full equilibrium population. While principal component analysis of the UV/vis spectra of the DNT-amine solutions reveals that only one absorbing species of significant concentration is formed, quantitative fits of Job's plots show that 1:1 association of DNT with the amines alone cannot explain the visible absorption spectra. Instead, the Job's plots can be accurately interpreted by deprotonation of DNT, with the amines acting as bases. The deprotonation equilibria lie far on the side of the unreacted DNT, preventing the detection by NMR of the deprotonated minority species that gives the solutions their strong blue color. The analysis of systems with DNT and n-butylamine, diethylamine, triethylamine, or benzylamine provides a consistent pK(a) of DNT in dimethyl sulfoxide of 15.3 ± 0.2.

Getting more out of a Job plot: determination of reactant to product stoichiometry in cases of displacement reactions and n:n complex formation.

The method of continuous variation (often referred to as Job's method) is an easy and common method for the determination of the reactant stoichiometry of chemical equilibria. The traditional interpretation of Job plots has been limited to complex association equilibria of the type nA + mB ⇌ A(n)B(m), while little focus has been placed upon displacement type reactions (e.g., A + B ⇌ C + D), which can give Job plots that look quite similar. We developed a novel method that allows the user to accurately distinguish between 1:1 complex association, 2:2 complex association, and displacement reactions using nothing more than a pocket calculator. This method involves preparing a Job plot of the system under investigation (using regularly spaced mole fractions), normalizing the measured quantities (such as the concentration of A(n)B(m) or C for the above reactions) to their maximum value (i.e., at mole fraction 0.5), and determining the sum of the normalized values. This sum is then compared with theoretically predicted normalized sum values that depend on the nature of the equilibrium. The relationship between, on the one hand, the sum of the normalized values and, on the other hand, the reaction equilibrium constant and the concentration of the stock solutions used for the preparation of the Job plot is also explored. The use of this new technique for the interpretation of Job plots permits users to readily determine information that can be obtained otherwise only with laborious additional experiments, as illustrated by the analysis of four Job plots taken from the literature.

Optimal NIV Medicare Access Promotion: Patients With OSA: A Technical Expert Panel Report From the American College of Chest Physicians, the American Association for Respiratory Care, the American Academy of Sleep Medicine, and the American Thoracic Society.

This document summarizes the work of the CPAP and bilevel PAP therapy for OSA Technical Expert Panel working group. For positive airway pressure (PAP) therapy, the most pressing current coverage barriers identified were: an insufficient symptom list describing all potential symptoms in patients with mild OSA; the 4 h per night of PAP usage requirement to keep the device; the additional sleep studies requirement to re-qualify for PAP or supplemental oxygen; and the inability to use telehealth visits for follow-up visits. Critical evidence supports changes to current policies and includes: symptom list inadequate to cover all scenarios based on updated clinical practice guidelines; published evidence that 2 h per night of PAP use can result in benefit to quality of life and other metrics; the costs of another sleep study not justified for all nonadherent patients or for supplemental oxygen due to other types of assessment currently available; and the remarkable success and acceptance of telehealth visits. To achieve optimal access for patients on PAP therapy, we make the following key suggestions: removing symptom criteria for mild OSA; reduce continued coverage criteria to > 2 h per night; eliminate the need for a sleep study to re-qualify if nonadherent or for new Centers for Medicare & Medicaid Services beneficiaries already on and adherent to PAP therapy; allow telehealth visits for documenting benefit and adherence; and allow PAP reports and domiciliary oximetry to qualify for supplemental oxygen with PAP if needed. This paper shares our best vision for bringing the right device to the right patient at the right time.

Orthogonal pre-use and post-use efficiency testing for single-use anion exchange chromatography.

Three efficiency tests for single-use AEX chromatography devices have been developed and applied to six capsule formats of a new, salt tolerant, single-use AEX product. All the tests have been designed to be performed with simple equipment and common reagents. By performing each of the three tests on undamaged capsules and capsules intentionally damaged with small defects, in tandem with Phi-X174 challenges in a high-salt buffer, relationships between test results and viral clearance have been obtained. A pre-use pressure-based installation verification test is simply performed during equilibration of the device and effective at identifying gross bypass defects, for example, due to internal seal breakage. Passing outcomes of a post-use installation validation bubble point test are associated with ≥ 5 log reduction value (LRV) of viral clearance. A new, non-destructive, pre-use AEX capacity test involves challenging the device with chloride ions and is orthogonal to the other two tests in that it can detect chemical defects, as well as mechanical ones. Passing outcomes of this test correspond to > 2 LRV viral clearance and provide in situ assurance of the expected AEX dynamic capacity prior to use. Selection of a pair of pre-use and post-use tests can provide robust risk reduction with respect to viral clearance by single-use AEX devices in biopharmaceutical purifications.

Contralateral Rerouting of Hypoglossal Nerve Implant Pulse Generator and Stimulation Lead.

As use of hypoglossal nerve stimulators has become more widespread in the treatment of obstructive sleep apnea, certain scenarios have dictated alterations to the previously described surgical technique. This report describes a situation in which revision of a hypoglossal nerve stimulator implant was required given the need for breast cancer surgery. It serves as the first description of the contralateral rerouting of a stimulation lead to a left-sided impulse generator and the first description of respiratory sensing lead placement within the left second intercostal space for such a device. Laryngoscope, 131:E2409-E2412, 2021.