Showing papers on "Hypoventilation published in 2013"

Sleep disorders in COPD: the forgotten dimension.

Abstract: Sleep in chronic obstructive pulmonary disease (COPD) is commonly associated with oxygen desaturation, which may exceed the degree of desaturation during maximum exercise, both subjectively and objectively impairing sleep quality. The mechanisms of desaturation include hypoventilation and ventilation to perfusion mismatching. The consequences of this desaturation include cardiac arrhythmias, pulmonary hypertension and nocturnal death, especially during acute exacerbations. Coexistence of COPD and obstructive sleep apnoea (OSA), referred to as overlap syndrome, has been estimated to occur in 1% of the general adult population. Overlap patients have worse sleep-related hypoxaemia and hypercapnia than patients with COPD or OSA alone. OSA has a similar prevalence in COPD as in a general population of similar age, but oxygen desaturation during sleep is more pronounced when the two conditions coexist. Management of sleep-related problems in COPD should particularly focus on minimising sleep disturbance via measures to limit cough and dyspnoea; nocturnal oxygen therapy is not generally indicated for isolated nocturnal hypoxaemia. Treatment with continuous positive airway pressure alleviates hypoxaemia, reduces hospitalisation and pulmonary hypertension, and improves survival.

Respiratory Management in the Patient with Spinal Cord Injury

Abstract: Spinal cord injuries (SCIs) often lead to impairment of the respiratory system and, consequently, restrictive respiratory changes. Paresis or paralysis of the respiratory muscles can lead to respiratory insufficiency, which is dependent on the level and completeness of the injury. Respiratory complications include hypoventilation, a reduction in surfactant production, mucus plugging, atelectasis, and pneumonia. Vital capacity (VC) is an indicator of overall pulmonary function; patients with severely impaired VC may require assisted ventilation. It is best to proceed with intubation under controlled circumstances rather than waiting until the condition becomes an emergency. Mechanical ventilation can adversely affect the structure and function of the diaphragm. Early tracheostomy following short orotracheal intubation is probably beneficial in selected patients. Weaning should start as soon as possible, and the best modality is progressive ventilator-free breathing (PVFB). Appropriate candidates can sometimes be freed from mechanical ventilation by electrical stimulation. Respiratory muscle training regimens may improve patients' inspiratory function following a SCI.

Pulmonary Issues in Patients with Chronic Neuromuscular Disease

Abstract: Patients with chronic neuromuscular diseases such as spinal cord injury, amyotrophic lateral sclerosis, and muscular dystrophies experience respiratory complications that are cared for by the respiratory practitioner. An organized anatomical approach for evaluation and treatment is helpful to provide appropriate clinical care. Effective noninvasive strategies for management of hypoventilation, sleep-disordered breathing, and cough insufficiency are available for these patients.

Comorbidities and Mortality in Hypercapnic Obese under Domiciliary Noninvasive Ventilation

Abstract: Background The higher mortality rate in untreated patients with obesity-associated hypoventilation is a strong rationale for long-term noninvasive ventilation (NIV). The impacts of comorbidities, medications and NIV compliance on survival of these patients remain largely unexplored.

Recommendations for anesthesia and perioperative management of patients with neuromuscular disorders

Abstract: Patients with neuromuscular disorders are at high risk of intraoperative and postoperative complications. General anesthesia in these patients may exacerbate respiratory and cardiovascular failure due to a marked sensitivity to several anesthetic drugs. Moreover, succinylcholine and halogenated agents can trigger life-threatening reactions, such as malignant hyperthermia, rhabdomyolysis and severe hyperkalemia. Therefore, regional anesthesia should be used whenever possible. If general anesthesia is unavoidable, special precautions must be taken. In particular, for patients at increased risk of respiratory complications (i.e., postoperative atelectasis, acute respiratory failure, nosocomial infections), noninvasive ventilation associated with aggressive airway clearance techniques can successfully treat upper airway obstruction, hypoventilation and airway secretion retention, avoiding prolonged intubation and tracheotomy. Anesthesia and perioperative management of patients with neuromuscular disorders are described in this article. To grade the strength of recommendations and the quality of evidence we adopted the GRADE approach. In case of low-quality evidence, these recommendations represent the collective opinion of the expert panel.

Basics of Mechanical Ventilation for Dogs and Cats

Abstract: Respiratory failure may occur due to hypoventilation or hypoxemia. Regardless of the cause, emergent anesthesia and intubation, accompanied by positive pressure ventilation, may be necessary and life saving. Long-term mechanical ventilation requires some specialized equipment and knowledge; however, short-term ventilation can be accomplished without the use of an intensive care unit ventilator, and can provide oxygen supplementation and carbon dioxide removal in critical patients.

Bedside adjustment of proportional assist ventilation to target a predefined range of respiratory effort.

Abstract: Objectives: During proportional assist ventilation with load-adjustable gain factors, peak respiratory muscle pressure can be estimated from the peak airway pressure and the percentage of assistance (gain). Adjusting the gain can, therefore, target a given level of respiratory effort. This study assessed the clinical feasibility of titrating proportional assist ventilation with load-adjustable gain factors with the goal of targeting a predefined range of respiratory effort. Design: Prospective, multicenter, clinical observational study. Settings: Intensive care departments at five university hospitals. Patients: Patients were included after meeting simple criteria for assisted mechanical ventilation. Interventions: Patients were ventilated in proportional assist ventilation with load-adjustable gain factors. The peak respiratory muscle pressure, estimated in cm H 2 O as (peak airway pressure – positive end-expiratory pressure) × [(100 – gain)/gain], was calculated from a grid at the bedside. The gain adjustment algorithm was defined to target a peak respiratory muscle pressure between 5 and 10 cm H 2 O. Additional recommendations were available in case of hypoventilation or hyperventilation. Results: Fifty-three patients were enrolled. Median time spent under proportional assist ventilation with load-adjustable gain factors was 3 days (interquartile range, 1–5). Gain was adjusted 1.0 (0.7–1.8) times per day, according to the peak respiratory muscle pressure target range in 91% of cases and because of hypoventilation or hyperventilation in 9%. Thirty-four patients were ventilated with proportional assist ventilation with load-adjustable gain factors until extubation, which was successful in 32. Eighteen patients required volume assist-controlled reventilation because of clinical worsening and need for continuous sedation. One patient was intolerant to proportional assist ventilation with load-adjustable gain factors. Conclusions: This first study assessing the clinical feasibility of titrating proportional assist ventilation with load-adjustable gain factors in an attempt to target a predefined range of effort showed that adjusting the level of assistance to maintain a predefined boundary of respiratory muscle pressure is feasible, simple, and often sufficient to ventilate patients until extubation. (Crit Care Med 2013;41:0–0)

Respiratory mechanics and ventilatory control in overlap syndrome and obesity hypoventilation

Abstract: The overlap syndrome of obstructive sleep apnoea (OSA) and chronic obstructive pulmonary disease (COPD), in addition to obesity hypoventilation syndrome, represents growing health concerns, owing to the worldwide COPD and obesity epidemics and related co-morbidities. These disorders constitute the end points of a spectrum with distinct yet interrelated mechanisms that lead to a considerable health burden. The coexistence OSA and COPD seems to occur by chance, but the combination can contribute to worsened symptoms and oxygen desaturation at night, leading to disrupted sleep architecture and decreased sleep quality. Alveolar hypoventilation, ventilation-perfusion mismatch and intermittent hypercapnic events resulting from apneas and hypopneas contribute to the final clinical picture, which is quite different from the “usual” COPD. Obesity hypoventilation has emerged as a relatively common cause of chronic hypercapnic respiratory failure. Its pathophysiology results from complex interactions, among which are respiratory mechanics, ventilatory control, sleep-disordered breathing and neurohormonal disturbances, such as leptin resistance, each of which contributes to varying degrees in individual patients to the development of obesity hypoventilation. This respiratory embarrassment takes place when compensatory mechanisms like increased drive cannot be maintained or become overwhelmed.

A Simple and Novel Method to Monitor Breathing and Heart Rate in Awake and Urethane-Anesthetized Newborn Rodents

Abstract: Rodents are most useful models to study physiological and pathophysiological processes in early development, because they are born in a relatively immature state. However, only few techniques are available to monitor non-invasively heart frequency and respiratory rate in neonatal rodents without restraining or hindering access to the animal. Here we describe experimental procedures that allow monitoring of heart frequency by electrocardiography (ECG) and breathing rate with a piezoelectric transducer (PZT) element without hindering access to the animal. These techniques can be easily installed and are used in the present study in unrestrained awake and anesthetized neonatal C57/Bl6 mice and Wistar rats between postnatal day 0 and 7. In line with previous reports from awake rodents we demonstrate that heart rate in rats and mice increases during the first postnatal week. Respiratory frequency did not differ between both species, but heart rate was significantly higher in mice than in rats. Further our data indicate that urethane, an agent that is widely used for anesthesia, induces a hypoventilation in neonates whilst heart rate remains unaffected at a dose of 1 g per kg body weight. Of note, hypoventilation induced by urethane was not detected in rats at postnatal 0/1. To verify the detected hypoventilation we performed blood gas analyses. We detected a respiratory acidosis reflected by a lower pH and elevated level in CO2 tension (pCO2) in both species upon urethane treatment. Furthermore we found that metabolism of urethane is different in P0/1 mice and rats and between P0/1 and P6/7 in both species. Our findings underline the usefulness of monitoring basic cardio-respiratory parameters in neonates during anesthesia. In addition our study gives information on developmental changes in heart and breathing frequency in newborn mice and rats and the effects of urethane in both species during the first postnatal week.

Increased Sympathetic and Decreased Parasympathetic Cardiac Tone in Patients with Sleep Related Alveolar Hypoventilation

Abstract: Measurements and Results: Time- and frequency-domain HRV measures (R-R, standard deviation of normal-to-normal RR interval (SDNN), very low frequency (VLF), low frequency (LF), high frequency (HF), LF/HF ratio) were calculated across all sleep stages as well as during wakefulness just before and after sleep during a 1-night polysomnography. In patients with SRAH and OSA, LF was increased during rapid eye movement (REM) when compared with control patients, whereas HF was decreased during REM and N1-N2 sleep stages. The LF/HF ratio was equally increased in patients with SRAH and OSA during REM and N1-N2. Correlation analysis showed that LF and HF values during REM sleep were correlated with minimal SatO2 and mean SatO2. Conclusions: Patients with SRAH exhibited an abnormal cardiac tone during sleep. This fact appears to be related to the severity of nocturnal oxygen desaturation. Moreover, there were no differences between OSA and SRAH, supporting the hypothesis that autonomic changes in OSA are primarily related to a reduced nocturnal oxygen saturation, rather than a consequence of other factors such as nocturnal respiratory events. Keywords: Autonomic nervous system, heart rate variability, hypoxia, obesity hypoventilation syndrome, sleep apnea, sleep disordered breathing. Citation: Palma JA; Urrestarazu E; Lopez-Azcarate J; Alegre M; Fernandez S; Artieda J; Iriarte J. Increased sympathetic and decreased parasym- pathetic cardiac tone in patients with sleep related alveolar hypoventilation. SLEEP 2013;36(6):933-940.

Continuous positive airway pressure in clinically stable patients with mild-to-moderate obesity hypoventilation syndrome and obstructive sleep apnoea.

Abstract: Background and objective The use of continuous positive airway pressure (CPAP) treatment in patients with obesity hypoventilation syndrome (OHS) and obstructive sleep apnoea (OSA) was evaluated, and factors that might predict CPAP treatment failure were determined. Methods A sleep study was performed in 29 newly diagnosed, clinically stable OHS patients. CPAP treatment was commenced if the apnoea–hypopnoea index was >15. Lung function, night-time oximetry, blood adipokine and C-reactive protein levels were assessed prospectively on enrollment and after 3 months. Treatment failure at 3 months was defined as daytime arterial partial pressure of carbon dioxide (PaCO2) >45 mm Hg and/or oxygen saturation (SpO2) 30% of the night-time oximetry study. Results All patients had severe OSA (median apnoea–hypopnoea index = 74.7 (62–100) with a nocturnal mean SpO2 of 81.4 ± 7), and all patients were treated with CPAP. The percentage of time spent below 90% saturation improved from 8.4% (0.0–39.0%) to 0.3% (0.4–4.0%). Awake PaCO2 decreased from 50 (47–53) mm Hg to 43 (40–45) mm Hg. Seven patients failed CPAP treatment after 3 months. PaCO2 at 1 month and mean night-time SpO2 during the first night of optimal CPAP were associated with treatment failure at 3 months (odds ratio 1.4 (1.03–1.98); P = 0.034 and 0.6 (0.34–0.93); P = 0.027). Conclusions CPAP treatment improves night-time oxygenation and daytime hypoventilation in selected clinically stable OHS patients who also have OSA. Patients with worse night-time saturation while on CPAP and higher daytime PaCO2 at 1 month were more likely to fail CPAP treatment.

Does pulse oximetry accurately monitor a patient's ventilation during sedated endoscopy under oxygen supplementation?

Abstract: INTRODUCTION: Pulse oximetry (SpO2) measures oxygen saturation but not alveolar ventilation. Its failure to detect alveolar hypoventilation during sedated endoscopy under oxygen supplementation has been reported. The aim of this study was to measure the masking effect of oxygen supplementation in SpO2 when alveolar hypoventilation develops during sedated endoscopy. METHODS: A total of 70 patients undergoing sedated diagnostic colonoscopy were randomly divided into two groups - oxygen supplementation group (n = 35) and room air breathing group (n = 35). SpO2 and end-tidal carbon dioxide (etCO2) were measured by non-intubated capnography during the procedure for all the patients. RESULTS: The rise of etCO2 caused by alveolar hypoventilation was comparable in the two groups after sedation. SpO2 was significantly higher in the oxygen supplementation group than in the room air breathing group (98.6% ± 1.4% vs. 93.1% ± 2.9%; p < 0.001) at peak etCO2, and oxygen supplementation caused SpO2 to be overestimated by greater than 5% when compared with room air. SpO2 at peak etCO2 was reduced from the baseline before sedation for the oxygen supplementation and room air breathing groups by 0.5% ± 1.1% and 4.1% ± 3.1%, respectively (p < 0.001). CONCLUSION: SpO2 alone is not adequate for monitoring alveolar ventilation during sedated endoscopy under oxygen supplementation due to possible delays in detecting alveolar hypoventilation in patients. Even if SpO2 decreases by only 1% during the procedure and its level remains near 100%, physicians should consider the onset of severe alveolar hypoventilation, which requires immediate intervention.

Indications, durations and outcomes of mechanical ventilation in dogs and cats with tick paralysis caused by Ixodes holocyclus: 61 cases (2008–2011)

Abstract: Objectives: The primary objectives of this research were to describe the indications for mechanical ventilation, the duration of mechanical ventilation and probability of survival in dogs and cats with respiratory failure induced by the Australian paralysis tick (Ixodes holocyclus). Methods: A retrospective case series and a retrospective single cohort study were conducted using dogs and cats with tick paralysis requiring mechanical ventilation. An index of oxygenating performance of the lung (PF ratio of partial pressure of oxygen in arterial blood to fraction of inspired oxygen) was derived from arterial blood gas analysis; patients euthanased because of veterinary costs were identified and Kaplan-Meier survival analyses performed. Results: In total, 36.6% of patients were ventilated because of hypoxaemia refractory to oxygen therapy, 38.3% because of hypoventilation, 18.3% because of unsustainable respiratory effort and 6.6% because of respiratory arrest. Median duration of mechanical ventilation was 23h, median time hospitalised was 84h and 63.9% of all patients requiring mechanical ventilation survived to discharge from the hospital. Survival probability increased to 75% when cases of cost-based euthanasia were right-censored rather than treated as deaths. The survival probability of patients ventilated because of hypoxaemia (52.6%) was significantly less than for those ventilated because of hypoventilation (90.5%). The first measured PF ratio after commencing mechanical ventilation was not significantly associated with survival probability. Conclusions: Dogs and cats with tick paralysis requiring mechanical ventilation to manage respiratory failure have reasonable survival probability. Dogs and cats requiring mechanical ventilation because of hypoventilation have a higher survival probability than those with oxygenation failure.

Hypocretin-1 deficiency in a girl with ROHHAD syndrome.

Abstract: Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare and complex pediatric syndrome, essentially caused by dysfunction of 3 vital systems regulating endocrine, respiratory, and autonomic nervous system functioning. The clinical spectrum of ROHHAD is broad, but sleep/wake disorders have received relatively little attention so far, although the central hypothalamic dysfunction would make the occurrence of sleep symptoms likely. In this case report, we expand the phenotype of ROHHAD with a number of striking sleep symptoms that together can be classified as a secondary form of narcolepsy. We present a 7-year-old girl with ROHHAD who displayed the classic features of narcolepsy with cataplexy: excessive daytime sleepiness with daytime naps, visual hallucinations, and partial cataplexy reflected in intermittent loss of facial muscle tone. Nocturnal polysomnography revealed sleep fragmentation and a sleep-onset REM period characteristic for narcolepsy. The diagnosis was confirmed by showing an absence of hypocretin-1 in the cerebrospinal fluid. We discuss potential pathophysiological implications as well as symptomatic treatment options.

Nocturnal Hypoxia in ALS Is Related to Cognitive Dysfunction and Can Occur as Clusters of Desaturations

Abstract: Background Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that leads to progressive weakness of the respiratory and limb muscles. Consequently, most patients with ALS exhibit progressive hypoventilation, which worsens during sleep. The aim of this study was to evaluate the relationship between nocturnal hypoxia and cognitive dysfunction and to assess the pattern of nocturnal hypoxia in patients with ALS.

Acute alcohol intoxication in adolescents: frequency of respiratory depression.

Abstract: , Abstract—Background: Adolescents and young adults are frequent users of alcohol. Younger patients may be more sensitive to the effects of alcohol than their adult counterparts, and toxicity has been known to occur at lower doses. Respiratory depression is a serious adverse effect of alcohol intoxication; however, current monitoring practices may not adequately detect respiratory depression. Objective: Our objective was to determine the frequency of hypoventilation as measured by capnography among adolescents with acute alcohol intoxication. Our secondary objective was to determine if an association exists between alcohol levels and incidence of hypoventilation. Methods: This was a prospective observational pilot study of patients 14–20 years of age with acute alcohol intoxication. Blood or breath alcohol measurements were obtained on arrival. Hourly measurements of vital signs including capnography were recorded. Results: Sixty-five subjects were analyzed. Mean alcohol level was 185 mg/dL. Twenty-eight percent of subjects had episodes of hypoventilation. Episodes occurred in similar proportions on arrival and during the first 5 h of measurements. There was no difference in alcohol levels between subjects who did and did not hypoventilate (185 mg/dL vs. 186 mg/dL; 95% confidence interval 29 to 25). Oxygen desaturations occurred in 14 subjects and were associated with hypoventilation (p = 0.015). Conclusions: Hypoventilation is common among adolescents who are acutely intoxicated with alcohol. It is independent of alcohol level and occurs at a steady rate during the first several hours of intoxication. Capnography should be consideredasanadditionalmonitoringdevicetodetectthese episodes and enhance patient safety. 2013 Elsevier Inc.

Necrotizing myositis causes restrictive hypoventilation in a mouse model for human enterovirus 71 infection

Abstract: Enterovirus 71 (EV71) infections are associated with a high prevalence of hand, foot and mouth disease (HFMD) in children and occasionally cause lethal complications. Most infections are self-limiting. However, resulting complications, including aseptic meningitis, encephalitis, poliomyelitis-like acute flaccid paralysis, and neurological pulmonary edema or hemorrhage, are responsible for the lethal symptoms of EV71 infection, the pathogenesis of which remain to be clarified. In the present study, 2-week-old Institute of Cancer Research (ICR) mice were infected with a mouse-adapted EV71 strain. These infected mice demonstrated progressive paralysis and died within 12 days post infection (d.p.i.). EV71, which mainly replicates in skeletal muscle tissues, caused severe necrotizing myositis. Lesions in the central nervous system (CNS) and other tissues were not observed. Necrotizing myositis of respiratory-related muscles caused severe restrictive hypoventilation and subsequent hypoxia, which could explain the fatality of EV71-infected mice. This finding suggests that, in addition to CNS injury, necrotic myositis may also be responsible for the paralysis and death observed in EV71-infected mice.

Anesthetic considerations for rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysfunction (ROHHAD) syndrome in children

Abstract: Rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysfunction is an increasingly common diagnosis in patients who are being seen at tertiary care children's hospitals. We present two cases of anesthetics from the authors' own experience in addition to a comprehensive review of the disorder and anesthetic implications.

Impact of stepwise hyperventilation on cerebral tissue oxygen saturation in anesthetized patients: a mechanistic study

Abstract: Positive-pressure ventilation is frequently adjusted in intubated patients. For example, hyperventilation is used in patients with elevated intracranial pressure or to facilitate neurosurgical procedures,1,2 and hypoventilation (‘permissive hypercapnia’) is used in patients with acute respiratory distress syndrome as part of protective lung ventilatory strategy.3 Cerebral blood flow (CBF) changes as a consequence to a change in blood carbon dioxide (CO2) level.4 If hemoglobin concentration, oxygen saturation, and cerebral metabolic rate are considered constant, a decrease in CBF will lead to a decrease in the amount of oxygen being delivered to the brain. As a consequence, cerebral oxygenation (the balance between cerebral oxygen demand and supply) will decrease. It has been shown that the change in cerebral oxygenation secondary to an adjustment in mechanical ventilation can be measured by cerebral tissue oxygen saturation (SctO2) based on frequency-domain near-infrared spectroscopy (NIRS) technology.5,6 However, it is not clear if the mechanism responsible for the change in SctO2 is exclusively due to the change in blood CO2 level or if changes in intrathoracic pressure and associated secondary changes in systemic hemodynamics, including blood pressure and cardiac output (CO), also contribute to the SctO2 change. The influence of anesthetic choice, propofol-remifentanil vs. sevoflurane, is also uncertain, especially considering the fact that potent inhalational agents possess intrinsic cerebral vasodilatory effect while intravenous agents do not.7 In this study, it was our hypothesis that the decrease in SctO2 induced by stepwise hyperventilation is due to both changes in blood CO2 level and changes in systemic hemodynamics. To test this hypothesis, we carried out this mechanistic study in which SctO2, end-tidal CO2 (ETCO2), mean arterial pressure (MAP), and CO were continuously and simultaneously measured throughout a stepwise increase in minute ventilation from hypoventilation (ETCO2 = 55 mmHg) to hyperventilation (ETCO2 = 25 mmHg) in patients anesthetized with either propofol-remifentanil or sevoflurane.

Nocturnal Anxiety in a Youth with Rapid-onset Obesity, Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD).

Abstract: Objective: Behavioral and psychiatric disorders are common in youth with rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD). We outline a rational approach to psychiatric treatment of a patient with a complex medical condition.

Investigation and management of childhood sleep apnoea.

Abstract: Sleep-disordered breathing includes disorders of breathing that affect airway patency, e.g. obstructive sleep apnoea syndrome, and also conditions that affect respiratory drive (central sleep disorders) or cause hypoventilation, either as a direct central effect or due to peripheral muscle weakness. Obstructive sleep apnoea syndrome (OSAS) is an increasingly-recognised clinical entity affecting up to 5.7% of children, which, if left untreated, is associated with adverse effects on growth and development including deleterious cognitive and behavioural outcomes. Evidence exists also that untreated OSAS impacts on cardiovascular risk. Close attention should be paid to assessment and investigation of this relatively common condition, instigating early and appropriate treatment to children with OSAS. First-line treatment in younger children is adenotonsillectomy, although other treatment options available include continuous positive airways pressure (CPAP), anti-inflammatory therapies (nasal corti costeroids and anti-leukotrienes), airway adjuncts and orthodontic appliances. Central sleep-disordered breathing may be related to immaturity of respiratory control and can be associated with prematurity as well as disorders such as Prader-Willi syndrome. In some cases, central apnoeas occur as part of a central hypoventilation disorder, which may be inherited, e.g. Congenital Central hypoventilation Syndrome, or acquired, e.g. Arnold-Chiari malformation, brain tumour, or spinal injury. The treatments of central breathing problems depend upon the underlying aetiology.Hippokratia 2013; 17 (3): 196-202

Perioperative respiratory management of pediatric patients with neuromuscular disease

Abstract: Patients with neuromuscular disorders undergoing general anesthesia present a special set of respiratory problems for perioperative management. While there are disease-specific concerns, there are many common themes in the respiratory management of patients with neuromuscular disorders. These problems are discussed in this review. Such common perioperative concerns include upper airway obstruction, chest wall restriction, postoperative hypoventilation, inadequate airway clearance, and chronic lower airway disease. Each of these challenges has an effective management approach, and careful planning can help avoid perioperative respiratory complications.

Fatal Overdose due to Confusion of an Transdermal Fentanyl Delivery System.

Abstract: Background. The use of transdermal fentanyl systems has increased over recent years, especially in patients with chronic pain. Large misuse potential and fatal outcomes have been described. Case Presentation. A 58-year-old patient presenting with clinical signs of opioid poisoning (hypoventilation, bradycardia, hypotension, and miosis) was admitted to our ICU. The first body check revealed a 75 mcg per hour fentanyl patch at the patient's right scapula. Some months ago, patient's aunt died after suffering from an oncological disease. During breaking up of her household, the patches were saved by the patient. Not knowing the risk of this drug, he mistook it as a heat plaster. Investigations. Laboratory test showed an impaired renal function and metabolic acidosis. Urine drug test was negative at admittance and 12 h later. CCT scan presented a global hypoxic brain disease. Treatment and Outcome. The patient was discharged 30 days after admittance in a hemodynamic stable condition but a vegetative state and transferred to a rehabilitation center. Learning Points. With the ongoing increase in fentanyl patch prescriptions for therapeutic reasons, it is likely that misuse cases will become more relevant. Conventional urine drug screening tests are not able to exclude the diagnosis fentanyl intoxication. History taking should include family member's drug prescriptions.

Reversal of pulmonary hypertension after diaphragm pacing in an adult patient with congenital central hypoventilation syndrome.

Abstract: IntroductionPatients with the congenital central hypoventilation syndrome (CCHS) suffer from life-threatening hypoventilation when asleep, making them dependent on mechanical ventilation (MV) at night or during naps. State-of-art respiratory management consists of intermittent positive-pressure ventilation via a tracheotomy or mask. In some patients hypoventilation is permanent, in which case ventilatory support must be extended to the waking hours. Diaphragm pacing can prove useful in such situations.Methods and ResultsThis report describes the case of a 26-year-old woman with CCHS in whom failure to achieve adequate MV led to life-threatening pulmonary hypertension (PH), with a systolic pulmonary artery pressure (PAP) of 80 mmHg and right ventricular hypertrophy, despite optimization of all possible measures and despite extensive therapeutic education efforts. Diaphragm pacing using laparoscopically implanted intradiaphragmatic phrenic nerve stimulation electrodes corrected alveolar hypoventilation and ...

Mechanical ventilation in a dog with acetylcholinesterase inhibitor toxicosis

Abstract: Background To describe a case of acetylcholinesterase inhibitor (AChEI) toxicosis with ventilatory failure that was successfully treated with mechanical ventilation (MV). Key Findings A 7-year-old, female spayed German Short-haired Pointer, presented with acute onset ptyalism, generalized muscle tremors, and diarrhea. Physical examination findings included evidence of muscarinic overstimulation in the parasympathetic nervous system (eg, diarrhea, ptyalism, lacrimation), and nicotinic overstimulation in the sympathetic nervous system (tachycardia), central nervous system (agitation), and the neuromuscular junction (eg, diffuse muscle fasciculations, tetraparesis). Point-of-care testing demonstrated hyperlactatemic metabolic acidosis and respiratory acidosis (hypoventilation). Hypoventilation progressed to respiratory failure and the dog lost its gag reflex necessitating emergency endotracheal intubation and MV. Additional treatments included atropine, parenteral antimicrobials (for aspiration pneumonia), pralidoxime, and supportive care. Weaning from the ventilator was achieved in 4 days. The dog was administered supplemental oxygen for 24 hours, and discharged 48 hours later with improved neurologic function and normal respiratory drive. Whole blood acetylcholinesterase activities measured on day 0, 2, and 4 and were consistent with AChEI toxicity. New or Unique Information Provided Specific AChEI toxicity (ie, carbamate and organophosphate) has been reported in the veterinary literature with good prognosis for survival and hospital discharge. While the existing veterinary literature suggests that ventilatory failure is rare in this disease syndrome, consideration for treatment with MV must be made for patients that develop respiratory failure (associated with hypoventilation, bronchoconstriction, bronchorrhea, or aspiration pneumonia).

Weese-Mayer DE: Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD)

Abstract: Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare disorder of respiratory control, the endocrine system, and the autonomic nervous system. Affected children typically present between 1.5 and 10 years of age with rapid and significant weight gain. Subsequently, they develop alveolar hypoventilation, autonomic nervous system dysfunction, and, if untreated, cardiorespiratory arrest. Early recognition and conservative management are essential to optimize outcome. With the epidemic of childhood obesity and related sleep-disordered breathing, it is essential that physicians are attuned to children who develop endogenous/pathological obesity and who therefore may be at risk for cardiorespiratory arrest.

Commentary: Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD): Remember Your ABCs (Airway, Breathing, Circulation).

Abstract: Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) is a devastating disorder that manifests in seemingly normal children, most typically between two and nine years of age. Because of the unique constellation of symptoms comprising the ROHHAD phenotype and inadequate public and medical awareness of the entity, diagnosis of affected children is often delayed and intervention is repeatedly incomplete and unsustained. Extensive experience with ROHHAD patients in the Center for Autonomic Medicine in Pediatrics (CAMP) at Ann & Robert H. Lurie Children’s Hospital of Chicago and the International ROHHAD Research Consortium informs us that children without early and adequate support of their hypoventilation (providing an adequate airway and breathing support) and anticipatory management of the ROHHAD phenotype (with particular attention to fluid balance and circulation) are most likely to have significant behavioral issues, deterioration, and heightened risk for sudden death. The authors of this published case of a 14 year old teenager, described ten years after initial rapid-onset obesity, should be commended for discussing ROHHAD from a psychiatry perspective. Many aspects of the ROHHAD disease burden seem insurmountable to caregivers, but the psychiatric symptoms and mood issues are described as the most devastating. Indeed, at times these symptoms may be so overwhelming that the other potentially life-threatening features of the ROHHAD phenotype escape attention. Consequently, it is imperative that our psychiatry colleagues become experts in the diagnosis and care of children with ROHHAD and that other specialists increase their awareness of the psychiatric phenotype because ROHHAD necessitates integrated care across all disciplines. Repeated mention of “exacerbation” in the published case report suggests an incomplete knowledge of the typical ROHHAD phenotype. To our knowledge, children with ROHHAD do not have “exacerbations.” Rather, there is an “unfolding” of the clinical features with advancing age such that vigilant care is needed to anticipate the “next” features in the constellation of findings that comprise the unique ROHHAD phenotype. The endocrinologist needs to move past consideration of exogenous obesity when interviewing an otherwise slim family to note the elevated prolactin levels, then at subsequent evaluations features of adipsic hypernatremia and still later hypothyroidism. The respiratory physiologist or a sleep expert might note the obstructive sleep apnea but they must be anticipating the alveolar hypoventilation that is unveiled after treatment of the obstructive sleep apnea. The autonomic expert might notice symptoms of autonomic dysregulation including the hypothermia, vasomotor insufficiency, and bradycardia, but they need to be watching for orthostatic intolerance and sequelae of unnoticed volume depletion. And in the event of a tumor of neural crest origin (ganglioneuroma or ganglioneuroblastoma), the oncologist needs to be attentive to the history of rapid weight gain so that prompt referral to a Center of Excellence for ROHHAD can be made. Taken together, specialists in all disciplines must take the lead from the general pediatrician who will be the first to note the dramatic rapid-onset weight gain. Centralization of each child’s care is essential to provide meticulous anticipatory management including prospective evaluation at two to three month intervals including physiologic monitoring in the laboratory and the home evaluating for the respiratory deterioration during sleep and wakefulness. Collaborative efforts on the part of all physicians providing complementary care to the child with initial features of the ROHHAD phenotype will optimize that child’s outcome. But diagnosis is only the first step in caring for the child with ROHHAD. Without aggressive attention to the child’s airway, breathing, and circulation, there is potential for irreversible deterioration in the child with ROHHAD. In the published case, desperation must have been sensed such that diaphragm pacers were surgically implanted in a child with no tracheostomy despite poor compliance with bi-level mask ventilation. Taken together, these features indicate that adequate airway and ventilatory support have not been achieved. Ideally, ventilatory management should be proactive and targeted to the child’s specific needs to optimize life support. Sustained compliance with ventilatory recommendations is essential for providing safety. Without continuous attention to airway, breathing, and circulation in the child with ROHHAD, it is not possible to interpret the effect of the proposed medications on the described insomnia, severe anxiety, auditory hallucinations, and disabling fears, and to maintain focus on neurocognitive outcome as we continue to work toward identification of a genetic basis and potential intervention strategies to decrease disease burden for these extraordinary children with ROHHAD.