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Showing papers on "Hypoventilation published in 2008"


Journal ArticleDOI
01 May 2008-Thorax
TL;DR: Both CPAP and BVS appear to be equally effective in improving daytime hypercapnia in a subgroup of patients with obesity hypoventilation syndrome without severe nocturnal hypoxaemia.
Abstract: Background: Untreated, obesity hypoventilation is associated with significant use of health care resources and high mortality. It remains unclear whether CPAP or bilevel ventilatory support should be used as initial management. The aim of this study was to determine if one form of positive pressure is superior to the other in improving daytime respiratory failure. Methods: Prospective, randomised study of patients with obesity hypoventilation referred with respiratory failure. After exclusion of persisting severe nocturnal hypoxaemia (SpO2 10 minutes) or carbon dioxide retention (>10mmHg) despite optimal CPAP, patients were randomly assigned to receive either CPAP or bilevel support over a 3-month period. Primary outcome was change in daytime carbon dioxide. Secondary outcome measures included daytime sleepiness, quality of life, compliance with therapy and psychomotor vigilance testing. Results: Thirty-six patients were randomized to either home CPAP (n=18) or bilevel support (n=18). The two groups did not differ significantly at baseline with regard to physiological or clinical characteristics. Following 3 months of therapy, daytime carbon dioxide levels decreased in both groups (CPAP 6+8 mmHg; bilevel 7+7 mmHg) with no between group differences. There was no difference in compliance between the two therapies (CPAP: 5.8+2.4hrs/night vs bilevel support: 6.1+ 2.1hrs/night). Although both groups reported improvement in daytime sleepiness, subjective sleep quality and psychomotor vigilance performance were better with bilevel support. Conclusions: Both CPAP and bilevel support appear to be equally effective in improving daytime hypercapnia in the subgroup of OHS patients without severe nocturnal hypoxaemia. The study was registered with the Australian Clinical Trials Registry (ACTRN01205000096651).

270 citations


Journal Article
Mark A. Powers1
TL;DR: The physiologic factors that lead to the obesity hypoventilation syndrome are overviewed and weight loss is the desirable long-term treatment for the obesity Hypoventilates syndrome.
Abstract: We only need to look around us to see that we are in an epidemic of obesity and obesity-related medical problems. The obesity hypoventilation syndrome is a disorder in which an obese person with normal lungs chronically hypoventilates. Obesity impairs ventilatory mechanics, increases the work of breathing and carbon dioxide production, results in respiratory muscle dysfunction, and reduces ventilatory response to hypercapnia. Sleep-disordered breathing is present in most patients with the obesity hypoventilation syndrome. When noninvasive ventilation can be successfully introduced, hypoventilation can usually be corrected. Weight loss is the desirable long-term treatment for the obesity hypoventilation syndrome. This paper concisely overviews the physiologic factors that lead to the obesity hypoventilation syndrome and discusses therapies for it.

183 citations


Journal ArticleDOI
TL;DR: Various bariatric procedures have been used to cause gastric stasis, decrease gastric volume, and induce malabsorption, with poor results in PWS patients in comparison with normal obese individuals.
Abstract: Prader-Willi syndrome (PWS) is a complex genetic disorder localized to chromosome 15 and is considered the most common genetic cause of the development of life-threatening obesity. Although some morbidities associated with PWS, including respiratory disturbance/hypoventilation, diabetes, and stroke, are commonly seen in obesity, others such as osteoporosis, growth hormone deficiency, and hypogonadism, and also altered pain threshold and inability to vomit, pose unique issues. Various bariatric procedures have been used to cause gastric stasis, decrease gastric volume, and induce malabsorption, with poor results in PWS patients in comparison with normal obese individuals.

128 citations


Journal ArticleDOI
TL;DR: Various hypothalamic-pituitary endocrine dysfunctions are associated with ROHHADNET, carrying a risk of misdiagnosis until other elements of the syndrome make it more easily recognizable.
Abstract: Context: Rapid-onset obesity with hypoventilation, hypothalamic, autonomic dysregulation, and neural tumor (ROHHADNET) is a newly described syndrome that can cause cardiorespiratory arrests and death. It mimics several endocrine disorders or genetic obesity syndromes during early childhood and is associated with various forms of hypothalamic-pituitary endocrine dysfunctions that have not yet been fully investigated. Objective: The current report aspires to facilitate the earlier recognition and appropriate treatment of the ROHHADNET syndrome when children present with various endocrine manifestations, such as early obesity, growth failure, pseudo-Cushing’s syndrome, glucocorticoid insufficiency, congenital hypopituitarism, or adrenal tumors. A more widespread knowledge of the syndrome will help characterize its molecular origin. Design: Endocrine studies were performed in six patients admitted for seemingly common early-onset obesity associated with growth failure in five of them. The six patients later s...

106 citations


Journal ArticleDOI
TL;DR: Experimental and clinical data regarding the impact of ventilation on TBI are reviewed, and potential mechanisms for the adverse effects of hyperventilation and hypocapnia on the injured brain are presented.

74 citations


Journal ArticleDOI
TL;DR: The cause underlying LO-CHS/HD remains poorly understood although recurrence in siblings argues for a monogenic disorder and the outcome remains poor for this group of patients.
Abstract: Late Onset Central Hypoventilation Syndrome associated with Hypothalamic Dysfunction (LO-CHS/HD) is a distinct entity among the clinical and genetic heterogeneous group of patients with late onset central hypoventilation. Here we report a series of 13 patients with LO-CHS/HD. Rapid onset obesity is the first symptom of HD followed by hypoventilation with a mean delay of 18 mos. The outcome remains poor for this group of patients and would benefit from early diagnosis to anticipate ventilation and possible metabolic disorders. Tumor predisposition is more frequent than initially suspected and as high as 40% in this series. These tumors of the sympathetic nervous system (TSNS) are usually differentiated and do not significantly worsen the prognosis. We report a familial case with recurrence in siblings. The cause underlying LO-CHS/HD remains poorly understood although recurrence in siblings argues for a monogenic disorder. We ruled out PHOX2B, ASCL1, and NECDIN as disease-causing genes by direct sequencing in our series of patients and discuss possible disease-causing mechanisms.

65 citations


Journal ArticleDOI
01 May 2008-Chest
TL;DR: NNV to treat severe, stable COPD remains controversial, although a subgroup of patients with hypercapnea and sleep-disordered breathing (SDB) seems most likely to respond favorably and preliminary results on a novel adaptive NNV mode are promising.

64 citations


Journal ArticleDOI
TL;DR: Diagnostic criteria for autosomal dominant parkinsonism, hypoventilation, depression and weight loss (Perry syndrome) are proposed and severe neuronal loss in the substantia nigra, less prominent neuronal Loss in the locus coeruleus, and no or few Lewy bodies are shown.

61 citations


Journal ArticleDOI
TL;DR: The models available to diagnose metabolic acidosis including CO2/HCO3– and physical chemistry‐derived (Stewart or Fencl‐Stewart) approaches are discussed, but it is proposed that the base excess and anion gap, corrected for hypoalbuminaemia and iatrogenic hyperchloraemia, remain most appropriate for clinical usage.
Abstract: Metabolic acidaemia (pH < 7.35 not primarily related to hypoventilation) is common amongst the critically ill and it is essential that clinicians caring for such patients have an understanding of the common causes. The exclusive elimination routes of volatile (carbon dioxide), organic (lactic and ketone) and inorganic (phosphate and sulphate) acids mean compensation for a defect in any one is limited and requires separate provision during critical illness. We discuss the models available to diagnose metabolic acidosis including CO2/HCO3(-) and physical chemistry-derived (Stewart or Fencl-Stewart) approaches, but we propose that the base excess and anion gap, corrected for hypoalbuminaemia and iatrogenic hyperchloraemia, remain most appropriate for clinical usage. Finally we provide some tips for interpreting respiratory responses to metabolic acidosis and how to reach a working diagnosis, the consequences of which are considered in Part 2 of this review.

60 citations


Journal ArticleDOI
TL;DR: The accuracy of estimation of PaCO2 by transcutaneous monitoring was generally good in comparison with standard arterial blood gases examination, and the device appears to be promising for use in obese patients to evaluate abnormalities in their alveolar ventilation.
Abstract: To determine the reliability of estimating arterial CO2 pressure (PaCO2) using a recently introduced transcutaneous CO2 pressure (PtcCO2) monitor in severe obese patients. Observational and interventional study. District hospital with respiratory ward and bariatric surgery unit. PtcCO2 was measured in 35 obese patients with varied pathology, including chronic obstructive pulmonary disease, obstructive sleep apnea syndrome and hypoventilation syndrome. Ten minutes after the probe had been attached to an earlobe, PtcCO2 was recorded immediately before arterial blood sampling. The PtcCO2 and PaCO2 values obtained with two methods were compared by Bland–Altman analysis. In a subgroup of 18 obese patients with chronic obstructive pulmonary disease and/or obstructive sleep apnea syndrome with moderate to severe hypercapnia both PtcCO2 and PaCO2 were re-evaluated during continuous positive airways pressure (CPAP) or bi-level positive airway pressure (Bi-PAP) treatment. The mean difference between PaCO2 and PtcCO2 was −1.4 mmHg, and the standard deviation of the difference was 1.3 mmHg. Bland–Altman analysis showed generally good agreement between the two methods with a 95% limit of agreement of −4 to 1.1. The agreement between methods did not significantly change before and during cPAP or Bi-PAP treatment in hypercapnic patients. The accuracy of estimation of PaCO2 by transcutaneous monitoring was generally good in comparison with standard arterial blood gases examination. The device appears to be promising for use in obese patients to evaluate abnormalities in their alveolar ventilation.

58 citations


Journal ArticleDOI
TL;DR: It is concluded that older patients with CHS frequently have arousal and central apnea, in addition to hypoventilation, when breathing spontaneously during sleep, which may be due to increased excitatory inputs to the respiratory system during REM sleep.
Abstract: The early literature suggests that hypoventilation in infants with congenital central hypoventilation syndrome (CHS) is less severe during rapid eye movement (REM) than during non-REM (NREM) sleep. However, this supposition has not been rigorously tested, and subjects older than infancy have not been studied. Given the differences in anatomy, physiology, and REM sleep distribution between infants and older children, and the reduced number of limb movements during REM sleep, we hypothesized that older subjects with CHS would have more severe hypoventilation during REM than NREM sleep. Nine subjects with CHS, aged (mean ± SD) 13 ± 7 yr, were studied. Spontaneous ventilation was evaluated by briefly disconnecting the ventilator under controlled circumstances. Arousal was common, occurring in 46% of REM vs. 38% of NREM trials [not significant (NS)]. Central apnea occurred during 31% of REM and 54% of NREM trials (NS). Although minute ventilation declined precipitously during both REM and NREM trials, hypoventilation was less severe during REM (drop in minute ventilation of 65 ± 23%) than NREM (drop of 87 ± 16%, P = 0.036). Despite large changes in gas exchange during trials, there was no significant change in heart rate during either REM or NREM sleep. We conclude that older patients with CHS frequently have arousal and central apnea, in addition to hypoventilation, when breathing spontaneously during sleep. The hypoventilation in CHS is more severe during NREM than REM sleep. We speculate that this may be due to increased excitatory inputs to the respiratory system during REM sleep.

Journal ArticleDOI
TL;DR: The clinical characteristics of OHS are defined, its pathophysiology is reviewed, its morbidity and mortality are discussed, and treatment strategies during ICU management using noninvasive positive pressure ventilation are offered.

Journal Article
TL;DR: The goal is to provide adequate gas exchange while minimizing hyperinflation and ventilator-induced lung injury and administering aggressive therapy to reduce airway inflammation and bronchoconstriction.
Abstract: Despite recent advances in our ability to manage asthma, there continues to be a small but important incidence of patients who present with severe asthma exacerbations that require ventilatory support. Mechanical ventilation in these patients is difficult and can be associated with substantial morbidity. Unfortunately, there is little in the way of randomized controlled trials to guide our therapeutic decisions in these patients. The goal is to provide adequate gas exchange while minimizing hyperinflation and ventilator-induced lung injury and administering aggressive therapy to reduce airway inflammation and bronchoconstriction. Although there is controversy on exactly what is the optimal method for mechanical ventilation in asthma, most experts agree that a general approach based on controlled hypoventilation is ideal.

Journal ArticleDOI
TL;DR: The generation of mouse models of CCHS provides tools for evaluating treatments aimed at alleviating both the respiratory symptoms and all other autonomic symptoms of C CHS.

Journal ArticleDOI
TL;DR: There is anecdotal evidence that CompSAS may be successfully treated using combined PAP therapy with oxygen, carbon dioxide, or the addition of dead space, but data are not sufficient to routinely recommend these methods.
Abstract: Patients with complex sleep apnea syndrome (CompSAS) present with features of obstructive sleep apnea syndrome but demonstrate not only instability of upper airway tone (leading to classic obstructive apneas and hypopneas) but also unstable, chemosensitive ventilatory control leading to repetitive central apneas or periodic breathing during sleep. The central apneas often become most apparent after application of continuous positive airway pressure (CPAP) to alleviate upper airway obstruction; patients continue to have fragmented sleep and repetitive desaturations as a result of central apneas and hypopneas. In some patients, central apneas appear to abate over time as a result of some form of adaptation to CPAP. How often this occurs is uncertain, however, and many patients with CompSAS require treatment that combines stabilization of the upper airway obstruction with treatment of respiratory center dysfunction. Adaptive servo-ventilation, which provides both a minimum pressure to hold the airway open and a precisely calculated ventilatory assist to minimize cyclic hypoventilation and hyperventilation, has emerged as a leading treatment. Noninvasive ventilation using bilevel positive airway pressure in the spontaneous-timed mode also may regulate ventilation in some patients with CompSAS. There is anecdotal evidence that CompSAS may be successfully treated using combined PAP therapy with oxygen, carbon dioxide, or the addition of dead space, but data are not sufficient to routinely recommend these methods.

Patent
10 Oct 2008
TL;DR: In this article, a system and method for treating and/or preventing periodic breathing characterized by cyclical hyperventilation and hypoventilation, examples of which include Cheyne-Stokes respiration and central sleep apnea, is described.
Abstract: A system and method for treating and/or preventing is described for treating periodic breathing characterized by cyclical hyperventilation and hypoventilation, examples of which include Cheyne-Stokes respiration and central sleep apnea. The system could also be used in the treatment of other conditions involving an impairment of respiratory drive.

Patent
16 May 2008
TL;DR: In this article, the authors present compounds, pharmaceutical compositions and methods for use in the prevention and treatment of cerebral insufficiency, including enhancement of receptor functioning in synapses in brain networks responsible for basic and higher order behaviors.
Abstract: This invention relates to compounds, pharmaceutical compositions and methods for use in the prevention and treatment of cerebral insufficiency, including enhancement of receptor functioning in synapses in brain networks responsible for basic and higher order behaviors. These brain networks, which are involved in regulation of breathing, and cognitive abilities related to memory impairment, such as is observed in a variety of dementias, in imbalances in neuronal activity between different brain regions, as is suggested in disorders such as Parkinson's disease, schizophrenia, respiratory depression, sleep apneas, attention deficit hyperactivity disorder and affective or mood disorders, and in disorders wherein a deficiency in neurotrophic factors is implicated, as well as in disorders of respiration such as overdose of an alcohol, an opiate, an opioid, a barbiturate, an anesthetic, or a nerve toxin, or where the respiratory depression results form a medical condition such as central sleep apnea, stroke-induced central sleep apnea, obstructive sleep apnea, congenital hypoventilation syndrome, obesity hypoventilation syndrome, sudden infant death syndrome, Rett syndrome, spinal cord injury, traumatic brain injury, Cheney-Stokes respiration, Ondines curse, Prader-Willi's syndrome and drowning. In a particular aspect, the invention relates to compounds useful for treatment of such conditions, and methods of using these compounds for such treatment.

Journal ArticleDOI
TL;DR: NIV improved endurance only in the non-COPD group, and this and the reduction in CO2 are achieved by lowering energetic requirements.
Abstract: Background: Noninvasive mechanical ventilation (NIV) is known to reduce hypoventilation and improves respiratory and peripheral muscle endurance in patients with chronic respiratory

Patent
19 Sep 2008
TL;DR: In this paper, the authors present compounds, pharmaceutical compositions and methods for use in the prevention and treatment of cerebral insufficiency, including enhancement of receptor functioning in synapses in brain networks responsible for basic and higher order behaviors.
Abstract: This invention relates to compounds, pharmaceutical compositions and methods for use in the prevention and treatment of cerebral insufficiency, including enhancement of receptor functioning in synapses in brain networks responsible for basic and higher order behaviors. These brain networks, which are involved in regulation of breathing, and cognitive abilities related to memory impairment, such as is observed in a variety of dementias, in imbalances in neuronal activity between different brain regions, as is suggested in disorders such as Parkinson's disease, schizophrenia, respiratory depression, sleep apneas, attention deficit hyperactivity disorder and affective or mood disorders, and in disorders wherein a deficiency in neurotrophic factors is implicated, as well as in disorders of respiration such as overdose of an alcohol, an opiate, an opioid, a barbiturate, an anesthetic, or a nerve toxin, or where the respiratory depression results form a medical condition such as central sleep apnea, stroke- induced central sleep apnea, obstructive sleep apnea, congenital hypoventilation syndrome, obesity hypoventilation syndrome, sudden infant death syndrome, Rett syndrome, spinal cord injury, traumatic brain injury, Cheney-Stokes respiration, Ondines curse, Prader-Willi's syndrome and drowning. In a particular aspect, the invention relates to compounds useful for treatment of such conditions, and methods of using these compounds for such treatment.

Patent
08 Aug 2008
TL;DR: In this article, the authors proposed a method for the prevention and treatment of cerebral insufficiency, including enhancement of receptor functioning in synapses in brain networks responsible for basic and higher order behaviors.
Abstract: This invention relates to compounds, pharmaceutical compositions and methods for use in the prevention and treatment of cerebral insufficiency, including enhancement of receptor functioning in synapses in brain networks responsible for basic and higher order behaviors. These brain networks, which are involved in regulation of breathing, and cognitive abilities related to memory impairment, such as is observed in a variety of dementias, in imbalances in neuronal activity between different brain regions, as is suggested in disorders such as Parkinson's disease, schizophrenia, respiratory depression, sleep apneas, attention deficit hyperactivity disorder and affective or mood disorders, and in disorders wherein a deficiency in neurotrophic factors is implicated, as well as in disorders of respiration such as overdose of an alcohol, an opiate, an opioid, a barbiturate, an anesthetic, or a nerve toxin, or where the respiratory depression results form a medical condition such as central sleep apnea, stroke-induced central sleep apnea, obstructive sleep apnea, congenital hypoventilation syndrome, obesity hypoventilation syndrome, sudden infant death syndrome, Rett syndrome, spinal cord injury, traumatic brain injury, Cheney-Stokes respiration, Ondines curse, Prader-Willi's syndrome and drowning, hi a particular aspect, the invention relates to bicyclic amide compounds useful for treatment of such conditions, and methods of using these compounds for such treatment.

Journal ArticleDOI
TL;DR: The objective is to evaluate the clinical application of long‐term non‐invasive ventilation in infants with life‐threatening ventilatory failure with regard to diagnosis, age at initiation, indication for and duration of treatment, clinical outcome and mortality and adverse effects.
Abstract: Aim: To evaluate the clinical application of long-term non-invasive ventilation (NIV) in infants with life-threatening ventilatory failure with regard to: diagnosis, age at initiation, indication for and duration of treatment, clinical outcome and mortality and adverse effects. Patients and methods: The medical records of 18 infants treated in a home setting during a 7-year period were reviewed. The criteria for ventilatory support were: (a) transcutaneous partial pressures of carbon dioxide (TcPCO2) >6.5 kPa and oxygen (TcPO2) < 8.5 kPa and (b) decreased cough ability and/or recurrent chest infections. Results: The median age at initiation was 4 months (range 1–12). NIV was initiated because of hypoventilation in 12 infants and because of reduced cough ability and/or recurrent infections in six infants. Tracheotomy was eventually needed in two infants. The median duration of treatment was 24 months (range 1–84). NIV produced significant improvements, with median TcPCO2 falling from 9.9 to 6.1 kPa, and median TcPO2 rising from 9.8 to 11.1 kPa. Conclusion: NIV can be successfully and safely used in infants with prolonged life-threatening ventilatory failure, potentially avoiding intubation and tracheotomy.

Proceedings ArticleDOI
14 Oct 2008
TL;DR: A physiological model of CO2 disposition, ventilatory regulation, and the effects of anesthetic agents on the control of breathing is proposed and can provide clinically relevant predictions of respiratory inhibition in the non-steady-state to enhance safety of drug delivery in the anesthetic practice.
Abstract: The ability of anesthetic agents to provide adequate analgesia and sedation is limited by the ventilatory depression associated with overdosing in spontaneously breathing patients. Therefore, quantitation of drug induced ventilatory depression is a pharmacokinetic-pharmacodynamic problem relevant to the practice of anesthesia. Although several studies describe the effect of respiratory depressant drugs on isolated endpoints, an integrated description of drug induced respiratory depression with parameters identifiable from clinically available data is not available. This study proposes a physiological model of CO 2 disposition, ventilatory regulation, and the effects of anesthetic agents on the control of breathing. The predictive performance of the model is evaluated through simulations aimed at reproducing experimental observations of drug induced hypercarbia and hypoventilation associated with intravenous administration of a fast-onset, highly potent anesthetic mu agonist (including previously unpublished experimental data determined after administration of 1 mg alfentanil bolus). The proposed model structure has substantial descriptive capability and can provide clinically relevant predictions of respiratory inhibition in the non-steady-state to enhance safety of drug delivery in the anesthetic practice.

Journal ArticleDOI
TL;DR: Some early evidence suggests that nocturnal supportive ventilation provides physiologic benefits as well as improvements in quality of life in patients with cystic fibrosis.

Journal ArticleDOI
TL;DR: Ventilation during sleep is under tight metabolic control, and can be destabilized by upper airway obstruction leading to snoring or obstructive apneas, inadequate respiratory pump muscle activity leading to hypoventilation, and central control instability leading to changes in metabolic feedback and loop gain.

Journal ArticleDOI
TL;DR: An otherwise healthy infant who developed unexplained apnea and long-segment Hirschsprung disease was found to have Haddad syndrome, a congenital disorder that features central congenital hypoventilation syndrome in conjunction with HaddAd syndrome.
Abstract: This report presents an otherwise healthy infant who developed unexplained apnea and long-segment Hirschsprung disease. After extensive evaluation that included a paired-like homeobox 2b gene (PHOX2B) analysis, he was found to have Haddad syndrome, a congenital disorder that features central congenital hypoventilation syndrome in conjunction with Haddad syndrome. Recent work has associated polyalanine repeats within the PHOX2B gene on chromosome 4p12 with central congenital hypoventilation syndrome, whereas PHOX2B knockout mice develop aganglionic bowels.

Journal ArticleDOI
TL;DR: The adjustment of the chemoreceptors can avoid the overload on the capacity of the respiratory muscles, at least in a number of patients or in the course of the disease, to avoid hypercapnia.
Abstract: The obesity hypoventilation syndrome (OHS) is defined by extreme overweight (BMI 30 kg/m2), daytime hypoventilation (PaCO2 > 45 mm Hg, the absence of other known causes of hypoventilation) and sleep-related breathing disorders. Obesity impairs breathing due to a restrictive ventilatory disorder, reduction of the capacity of respiratory muscles and diminishment of the ventilatory response. The restriction cannot serve as the only explanation of OHS because body weight or compliance on the one hand and hypoventilation on the other hand only correlate weakly. Obesity increases the work of breathing by greater body mass with its increased oxygen demand, impaired diaphragmatic mobility, upper airway obstruction, and oxygen desaturation which result in an inadequacy of oxygen demand and supply. The adjustment of the chemoreceptors can avoid the overload on the capacity of the respiratory muscles, at least in a number of patients or in the course of the disease. This disproportion results in hypercapnia. Furthermore, the level of leptin is an important factor in the pathophysiology of OHS. The blood level of leptin correlates with the body fat mass in humans. However, there seems to be a relative leptin deficiency in the brain in overweight humans. Therefore, in contrast to animals, leptin cannot sufficiently increase ventilation in man to avoid hypercapnia.

Journal ArticleDOI
TL;DR: A bag-valve device with limited maximum inspiratory gas flow developed to reduce the risk of stomach inflation in an unprotected airway was evaluated and provided inadequate tidal volumes during simulated cardiopulmonary resuscitation and would result in hypoventilation in a patient.
Abstract: In a bench model, we evaluated a bag-valve device (Smart Bag ® MO) with limited maximum inspiratory gas flow developed to reduce the risk of stomach inflation in an unprotected airway. During simulated cardiopulmonary resuscitation with uninterrupted chest compressions, ventilation with the "disabled" Smart Bag ® MO or an adult self-inflating bag-valve device provided only adequate tidal volumes if inspiratory time was 0.5 s. Ventilation with the "enabled" Smart Bag® MO, even in ventilation windows of 0.5 s, provided inadequate tidal volumes during simulated cardiopulmonary resuscitation and would result in hypoventilation in a patient.

01 Jan 2008
TL;DR: CPAP can improve oxygenation and sleep apnea-hypopnea,but can not be proven having effects of decreased blood pressure.
Abstract: Objective To explore the effect of continuous positive airway pressure (CPAP) to blood pressure of obstructive sleep apnea-hypopnea syndrome (OSAHS).Methods We evaluated the variation of blood pressure and AHI ,oxygenation in the OSAHS patients after using CPAP.Results AHI is obviously decreased (P=0.000) ,oxygenation is obviously increased (P=0.000) after using CPAP. But blood pressure is not obviously decreased (P0.05).Conclusion CPAP can improve oxygenation and sleep apnea-hypopnea,but can not be proven having effects of decreased blood pressure.

Journal ArticleDOI
TL;DR: Electrocardiographic findings of ST-segment and T-wave changes during the maintenance anesthesia were evident in animals with hypercapnia, a disorder that should be promptly corrected with assisted or controlled ventilation to prevent complicated arrhythmias.
Abstract: The purpose of this study was to clarify the degree of influence of anesthetic agents commonly used during anesthesia on the heart conduction systems of geriatric dogs, with or without the presence of electrocardiographic changes in the pre-anesthetic electrocardiogram and also to determine the possible causes of ST-segment and T-wave changes during anesthesia, by monitoring ventilation and oxygenation. 36 geriatric dogs were evaluated. In addition to electrocardiographic evaluation, the pre-anesthetic study included serum levels of urea, creatinine, total protein, albumin and electrolytes. The pre-anesthetic medication consisted of acepromazine (0.05mg kg-1) in association with meperidine (3.0mg kg-1) by IM injection. Anesthesia was induced with propofol (3.0 to 5.0mg kg-1) by IV injection and maintained with isoflurane in 100% oxygen. During the anesthesia, the animals were monitored by continued computerized electrocardiogram. Systemic blood pressure, heart rate, respiratory rate, end-tidal carbon dioxide, partial pressure of carbon dioxide in arterial blood, arterial oxygen saturation, partial pressure of arterial oxygen and oxygen saturation of hemoglobin were closely monitored. During maintenance anesthesia, normal sinus rhythm was more common (78%). ST-segment and T-wave changes during the anesthetic procedure were quite common and were related to hypoventilation. The use of isoflurane did not result in arrhythmia, being therefore a good choice for this type of animal; Electrocardiographic findings of ST-segment and T-wave changes during the maintenance anesthesia were evident in animals with hypercapnia, a disorder that should be promptly corrected with assisted or controlled ventilation to prevent complicated arrhythmias.

Journal ArticleDOI
TL;DR: In conclusion, search for and removal of an ovarian teratoma should be promptly considered after the diagnosis of anti-NMDAR encephalopathy and early removal of tumor should be considered.
Abstract: Anti-NMDAR encephalopathy is included in paraneoplastic limbic encephalopathy and show the good response to treatment compared to other paraneoplastic syndromes. Treatment of anti-NMDAR encephalopathy includes immunotherapy and/or tumor removal. About 65% of patients with anti-NMDAR encephalopathy had fully or near-full recovery. Immunotherapy is principally necessary and effective in patients with and without tumor. Corticosteroids and intravenous immunoglobulin are most frequently used. It is likely that patients who do not respond to one form of immunotherapy might respond to others regimens including plasmapheresis, cyclophosphamide, and rituximab. A tumor was found in 58% of patients with anti-NMDAR encephalopathy. Early removal of tumor should be considered based on following reasons. First, patients with ovarian teratoma showed higher mortality and higher titer of anti-NMDAR antibody compared with those without. Second, relapsing neurological symptoms occurred in 13% of patients, usually related to a delay in tumor diagnosis. Third, when a tumor was found and removed, recovery was faster and predictable. However, early removal of tumor cannot be conducted because of unstable conditions such as hypoventilation and dyskinesias. In supportive cares, severe central hypoventilation requires mechanical ventilation. The involuntary movements and facial dyskinesias are refractory to anti-epileptic drugs. In conclusion, search for and removal of an ovarian teratoma should be promptly considered after the diagnosis of anti-NMDAR encephalopathy.