No abstract available.
Hirschsprung Disease* ; Hypoventilation*

BACKGROUND: There are many factors such as diffusion abnormality, V/Q mismatch, intrapulmonary shunt, alveolar hypoventilation and FIO2 in reducing arterial hypoxemia. Intrapulmonary shunting can be due to blood going from the right to the left side of the heart without respiring with alveolar gas(true shunt mechanism) or blood that respires but achieves a PaO2 less than the ideal (shunt effect mechanism). Understanding the portion of true shunt in patients with hypoxemia is very important indicator to analyze the effects of oxygen therapy. Several equations are used for calculation of physiologic shunt. The aim of this study was to calculate and compare shunts derived from four shunt equations; classic physiologic, estimated, modified clinical and simple equations. METHOD: After cardiovascular stability following open heart surgery, 40 patients were mechanically ventilated with an FIO2=1.0. Arterial and mixed blood gases were measured. We calculated and compared shunts by classic physiologic [S/T=(CcO2 CaO2)/(CcO2 CO2)], estimated [S/T=(CcO2 CaO2)/ (3.5 CcO2 CO2)], modified clinical [S/T= AaDO2 0.0031/(AaDO2 0.0031 CcO2 CaO2)], and simple equations [S/T=AaDO2/20]/ RESULTS: Shunts by classic physiologic, estimated, and modified clinical shunt equation were 26.9 8.5%, 25.1 7.1%, and 26.3 8.2%, respectively and did not differ one another significantly. Shunts by simple shunt equations was 18.8 6.2% and significantly lower than those by other 3 equations(P<0.05). CONCLUSIONS: It is reasonable to conclude that in post-open heart patients with stable cardiovascular function and mechanically ventilated with an FIO2=1.0, classic physiologic, estimated, and modified clinical shunt equations show a reliable reflection of the physiologic shunt. But simple equation (AaDO2/20) might be used as a simple estimate.
Anoxia ; Diffusion ; Gases ; Heart ; Humans ; Hypoventilation ; Oxygen ; Thoracic Surgery

BACKGROUND AND PURPOSE: Cerebrovascular reactivity (CVR) can be estimated by measuring the change of cerebral blood flow that occurs during vasostimulation. To estimate the cerebrovascular reactivity, we investigated the change of flow velocity of the internal carotid artery (ICA) and the middle cerebral artery (MCA) during hyperventilation and hypoventilation with the transcranial doppler. So we studied whether the CVR measured by this method could show a significant difference between the normal and the atherosclerotic subjects and whether the CVR may decrease with age in normal gubjects. METHODS: Using transcranial doppler, we measured the mean velocity (Vm), the pulsatility index (P.I.) at the resting state, the end of breath-holding and the end of hyperventilation in 30 normal and 10 atherosclerotic subjects, so we calculated the percentile change of mean velocity (% Vm) and P.I. (% P.I.) after the vasostimulation. We estimated the change of Vm, P.I., % Vm and % P.I. By the age group and compared those parameters between the age-matched normal control and atherosclerotic subjects. RESULTS: The Vm in ICA and MI significantly decreased with age (p<0.01), but there was no significant difference in Vm and P. I. Between normal and atherosclerotic subjects. The % Vm and % P.I. In response to hyperventilation significantly decreased with age in ICA, M1, M2 and there was significant difference in % Vm of ICA and M1 after breath-holding and % Vm of ICA after hyperventilation between the normal and atherosclerotic subjects. CONCLUSION: The breath-holding and hyperventilation tests could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied in the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.
Carotid Artery, Internal ; Humans ; Hyperventilation ; Hypoventilation ; Middle Cerebral Artery ; Stroke

Child, Preschool ; Humans ; Male ; Obesity Hypoventilation Syndrome ; diagnosis ; therapy

Humans ; Sleep Apnea, Central/therapy* ; Hypoventilation/congenital* ; Homeodomain Proteins

Obesity-Hypoventilation syndrome (OHS) is characterized by morbid obesity, hypoxia, and hypercapnea during wakefulness without parechymal lung disease or severe obstructive sleep apnea. A woman was admitted because of mental deterioration and diagnosed as OHS on the basis of obesity and hypoventilation, while awake, after ruling out other causes. By bilevel positive airway pressure (BiPAP) therapy, hypercapnea and hypoxia were resolved. We report that BiPAP can be an effective treatment for severe hypercapnea and hypoxia in OHS, which obviate the need for invasive endotracheal intubation.
Anoxia ; Female ; Humans ; Hypoventilation ; Intubation, Intratracheal ; Lung Diseases ; Obesity ; Obesity Hypoventilation Syndrome* ; Obesity, Morbid ; Sleep Apnea, Obstructive ; Wakefulness

BACKGROUND: The purpose of this study was to define morphine's effects on resting ventilation and the ventilatory response to hypoxia and hypercarbia. METHODS: Six healthy nonsmoking young adult males were tested for the respiratory effects of intravenous morphine (0.15 mg/kg). Test began with baseline measurement of resting ventilation, isocapnic hypoxic ventilatory response (HVR), and normoxic hypercapnic ventilatory response (HCVR). After baseline measurement, morphine was administered and ventilatory responses were determined 20 and 40 min postinfusion. RESULTS: Morphine significantly decreased resting ventilation, hypoxic ventilatory response, and hypercarbic ventilatory response. Resting hypoventilation manifested as a peak rise in PETCO2 from 38.0+/-1.4 to 42.8+/-1.0 mmHg ( SEM) at 20 min (p<0.05). Hypoxic ventilatory response, measured as the slope of the ventilatory response to hypoxia, decreased from a control of 20.7+/-3.8 to 14.5+/-7.2 at 20 min after morphine (p<0.05). Hypercapnic ventilatory response, measured as the slope of the ventilatory response to hypercarbia, also decreased from 34.9+/-7.5 to 11.1+/-4.9 (p<0.05) 20 min after morphine. CONCLUSION: These decreased responsiveness to the chemical stimuli to breathing may contribute to the ventilatory depression frequently seen after administration of morphine.
Anoxia* ; Humans ; Hyperventilation* ; Hypoventilation ; Male ; Morphine* ; Respiration ; Respiratory Insufficiency ; Ventilation ; Young Adult

Adult ; Humans ; Male ; Obesity Hypoventilation Syndrome ; diagnosis ; therapy ; Polycythemia ; diagnosis ; therapy

Obesity, with an increasing prevalence,has become one of the most common metabolic diseases. Obesity is associated with many respiratory diseases, especially sleep-related breathing disorders including obstructive sleep apnea-hypopnea syndrome, obesity hypoventilation syndrome, and overlap syndrome. This article reviews the association between obesity and these sleep-related breathing disorders.
Humans ; Obesity ; complications ; Obesity Hypoventilation Syndrome ; etiology ; Pulmonary Disease, Chronic Obstructive ; complications ; Sleep Apnea, Obstructive ; etiology

PURPOSE: Imploding antrum (silent sinus) syndrome has clinical features of enophthalmos and hypoglobus after a downward collapse of inferior orbital wall with an ipsilateral volume decrease of maxillary sinus. We present a case of imploding antrum syndrome after an orbital decompression surgery. CASE SUMMARY: A 26-year-old female underwent inferomedial wall orbital decompression surgery through a caruncular approach to reduce exophthalmos. At 14 months after surgery, her right eye showed 2 mm of enophthalmos and orbital CT scan revealed both maxillary sinusitis. At 28 months after surgery, 3 mm of enophthalmos and hypoglobus of the right were observed, and an orbital CT scan was taken. Orbital CT scan showed a downward collapse of inferior orbital wall, a volume decrease and inward bowing of the maxillary sinus, and a maxillary opacification on the right side, which are typical findings of imploding antrum (silent sinus) syndrome. CONCLUSIONS: Imploding antrum (silent sinus) syndrome after orbital decompression surgery is a rare complication. Considering that any prolapsed orbital fat after orbital decompression surgery could result in imploding antrum syndrome with hypoventilation of a maxillary sinus, care should be taken to keep the maxillo-ethmoidal interface (bony strut) intact, which helps maintain maxillary aeration.
Adult ; Decompression ; Enophthalmos ; Exophthalmos ; Eye ; Female ; Humans ; Hypoventilation ; Maxillary Sinus ; Maxillary Sinusitis ; Orbit