Hypoxemia

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Hypoxemia

  • arterial hypoxemia


  • Selected Abstracts


    Evolution of hypoxemia in patients with severe cirrhosis

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 10 2002
    Isabelle Colle
    Abstract Background and Aim: Hypoxemia is common in patients with cirrhosis but the natural history of this syndrome is unknown. The aim of this study was to follow a series of patients with cirrhosis and to compare patients with and without hypoxemia to determine their risk of complications and survival rate. Methods: Fifty-eight consecutive Child,Pugh C patients with cirrhosis were included and followed up for 1,18 months. Blood gas measurements and plasma endothelin levels were measured in all patients. Blood gas measurements were repeated in 34 patients. Results: Hypoxemia was present in 35 patients (60%) (alveolar-arterial oxygen (AaO2) gradient > 20 mmHg) but none had pulmonary symptoms. There was no significant difference in liver tests and plasma endothelin levels between hypoxemic and non-hypoxemic patients. The occurrence of variceal bleeding and survival rate was not significantly different between the two groups. The AaO2 gradient worsened in nine patients and normalized in six of the hypoxemic patients. The AaO2 gradient increased to more than 20 mmHg in seven non-hypoxemic patients. There was no relationship between AaO2 gradient changes and Child,Pugh score grade changes. Conclusion: Asymptomatic hypoxemia is common in patients with severe cirrhosis but it is not a predictive factor of short-term complications or mortality. These results should be considered when deciding on liver transplantation. [source]


    Exercise-induced hypoxemia may be caused by an insufficient stimulating effect of exercise on the pulmonary generation of nitric oxide

    ACTA PHYSIOLOGICA, Issue 2 2005
    Dr Lars E. Gustafsson
    No abstract is available for this article. [source]


    ORIGINAL INVESTIGATIONS: Potential Faces of Patent Foramen Ovale (PFO PFO)

    ECHOCARDIOGRAPHY, Issue 8 2010
    F.R.C.P., Tasneem Z Naqvi M.D.
    Background: Patent foramen ovale (PFO) is diagnosed on echocardiography by saline contrast study with or without color Doppler evidence of shunting. PFO is benign except when it causes embolic events. Methods and Results: In this report, we describe unique additional manifestations related to the diagnosis and presentation of PFO. These include demonstration of PFO during the release phase of "sigh" on the ventilator in the operating room, use of a separate venipuncture to allow preparation of blood-saline-air mixture after multiple failed saline bubble injections, resting and stress hypoxemia related to left to right shunting across a PFO in the absence of pulmonary hypertension, presentation of quadriperesis secondary to an embolic event from a PFO and development of a thrombus on the left atrial aspect of PFO in a patient with atrial fibrillation, and on the right atrial aspect of PFO in a patient who had undergone repair of a flail mitral valve. Finally, in one patient with end-stage renal disease, aortic valve endocarditis and periaortic abscess, PFO acted as a vent valve relieving right atrial pressure following development of aortoatrial fistula. Conclusion: PFO diagnosis can be elusive if appropriate techniques are not used during saline contrast administration. PFO can present as hypoxemia in the absence of pulmonary hypertension, can be a rare cause of quadriperesis, and can be associated with thrombus formation on either side of interatrial septum. Finally, PFO presence can be lifesaving in those with sudden increase in right atrial pressure such as with aortoatrial fistula. (Echocardiography 2010;27:897-907) [source]


    Echocardiographic Detection of Intrapulmonary Shunting in a Patient with Hepatopulmonary Syndrome: Case Report and Review of the Literature

    ECHOCARDIOGRAPHY, Issue 1 2006
    Richard Pacca M.D.
    Transthoracic echocardiography is a useful tool in the evaluation of patients with intrapulmonary and intracardiac shunts. We describe a case of a 49-year-old female with severe hypoxemia in the setting of aortic stenosis and cirrhosis of the liver. The use of agitated saline contrast during an echocardiography study helped to establish the diagnosis of intrapulmonary arteriovenous shunting consistent with the hepatopulmonary syndrome, thereby confirming the etiology of her symptoms and laboratory findings. This case report highlights the utility of echocardiography in diagnosing intrapulmonary shunts and assists in the understanding of the pathophysiology of hypoxemia in such patients. [source]


    Status Epilepticus,Induced Neuronal Loss in Humans Without Systemic Complications or Epilepsy

    EPILEPSIA, Issue 8 2000
    Denson G. Fujikawa
    Summary: Purpose: To determine the regional distribution of neuronal damage caused strictly by status epilepticus (SE) without systemic complications, underlying brain pathology, or a history of preexisting epilepsy. Methods: The medical records and electroencephalograms (EEGs) of three deceased patients who developed SE in the hospital were reviewed. Their brains were formalin-fixed, and 17 brain regions were selected, embedded in paraffin, and sectioned. Alternate sections were stained with either hematoxylin and eosin and cresyl violet to determine the extent of neuronal loss and gliosis or glial fibrillary astrocytic protein to confirm the extent of astrocytic proliferation. Results: The three patients died 11 to 27 days after the onset of focal motor SE; none had hypotension, hypoxemia, hypoglycemia, or significant hyperthermia. Two patients had no prior seizures and no underlying brain pathology. The third patient, who had leptomeningeal carcinomatosis, had one seizure 2 months before the onset of SE. The duration of SE was 8.8 hours to 3 days. EEGs showed unilateral temporal lobe sharp-wave discharges in one patient and independent temporal lobe sharp-wave discharges bilaterally in the other two patients. In addition to widespread neuronal loss and reactive gliosis in the hippocampus, amygdala, dorsomedial thalamic nucleus, and Purkinje cell layer of the cerebellum, we report for the first time periamygdaloid (piriform) and entorhinal cortical damage occurring acutely after SE in humans. Conclusions: In the absence of systemic complications or preexisting epilepsy, SE produces neuronal loss in a distribution similar to that from domoic acid-induced SE in humans and from kainic acid- and pilocarpine-induced SE in rats. [source]


    PRECLINICAL STUDY: Mechanisms of respiratory insufficiency induced by methadone overdose in rats

    ADDICTION BIOLOGY, Issue 1 2010
    Lucie Chevillard
    ABSTRACT Methadone may cause respiratory depression. We aimed to understand methadone-related effects on ventilation as well as each opioid-receptor (OR) role. We studied the respiratory effects of intraperitoneal methadone at 1.5, 5, and 15 mg/kg (corresponding to 80% of the lethal dose-50%) in rats using arterial blood gases and plethysmography. OR antagonists, including intravenous 10 mg/kg-naloxonazine at 5 minutes (mu-OR antagonist), subcutaneous 30 mg/kg-naloxonazine at 24 hours (mu1-OR antagonist), 3 mg/kg-naltrindole at 45 minutes (delta-OR antagonist) and 5 mg/kg-Nor-binaltorphimine at 6 hours (kappa-OR antagonist) were pre-administered. Plasma concentrations of methadone enantiomers were measured using high-performance liquid chromatography coupled to mass-spectrometry. Methadone dose-dependent inspiratory time (TI) increase tended to be linear. Respiratory depression was observed only at 15 mg/kg and characterized by an increase in expiratory time (TE) resulting in hypoxemia and respiratory acidosis. Intravenous naloxonazine completely reversed all methadone-related effects on ventilation, while subcutaneous naloxonazine reduced its effects on pH (P < 0.05), PaCO2 (P < 0.01) and TE (P < 0.001) but only partially on TI (P < 0.001). Naltrindole reduced methadone-related effects on TE (P < 0.001). Nor-binaltorphimine increased methadone-related effects on pH and PaO2 (P < 0.05) Respiratory effects as a function of plasma R -methadone concentrations showed a decrease in PaO2 (EC50: 1.14 µg/ml) at lower concentrations than those necessary for PaCO2 increase (EC50: 3.35 µg/ml). Similarly, increased TI (EC50: 0.501 µg/ml) was obtained at lower concentrations than those for TE (EC50: 4.83 µg/ml). Methadone-induced hypoxemia is caused by mu-ORs and modulated by kappa-ORs. Additionally, methadone-induced increase in TE is caused by mu1- and delta-opioid receptors while increase in TI is caused by mu-ORs. [source]


    Comprehensive geriatric assessment of elderly highlanders in Qinghai, China II: The association of polycythemia with lifestyle-related diseases among the three ethnicities

    GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 4 2009
    Kiyohito Okumiya
    Aim: The objective of this study is to disclose the association of polycythemia with lifestyle-related diseases (hypertension, obesity and glucose intolerance) among the three ethnicities in Qinghai, China. Methods: The subjects were 393 elderly people (247 Han, 97 Tibetan and 49 Mongolian) aged 60 years and more living in Qinghai (3000 m a.s.l.) in China. The associated factors with polycythemia were analyzed in the subjects. Excessive polycythemia was defined as hemoglobin concentration over 20 mg/dL. Results: Polycythemia was associated with men, hypoxemia, obesity and high diastolic blood pressure (DBP) in the elderly in Qinghai. Male sex was associated with polycythemia in all ethnicities. Obesity was associated with Han and Tibetan men. Glucose intolerance and activities of daily living were not directly associated with polycythemia after adjustment for sex. There were 7.9% with excessive polycythemia. Independently-associated factors for excessive polycythemia were male sex, body mass index of 25 or more, SpO2 of less than 85%, DBP of 85 mmHg or more and Han ethnicity (vs Tibetan) by multiple logistic regression. Conclusion: There was a close association of polycythemia with diastolic hypertension and obesity in lifestyle-related diseases in high-altitude elderly people. Han people had a higher hemoglobin concentration after adjustment of lifestyle-related diseases compared with Tibetan people. The difference of hemoglobin concentration may be due to Tibetans undergoing a much longer period of adaptation than Han people. Further study is needed to disclose the association between the difference of hypoxic adaptation, lifestyle-related diseases and chronic mountain sickness for their prevention. [source]


    Sleep apnea and dialysis therapies: Things that go bump in the night?

    HEMODIALYSIS INTERNATIONAL, Issue 4 2007
    Mark L. UNRUH
    Abstract Sleep apnea has been linked to excessive daytime sleepiness, depressed mood, hypertension, and cardiovascular disease in the general population. The prevalence of severe sleep apnea in the conventional thrice-weekly hemodialysis population has been estimated to be more than 50%. Sleep apnea leads to repetitive episodes of hypoxemia, hypercapnia, sleep disruption, and activation of the sympathetic nervous system. The hypoxemia, arousals, and intrathoracic pressure changes associated with sleep apnea lead to sympathetic activation, endothelial dysfunction, oxidative stress, and inflammation. Because sleep apnea has been shown to be widespread in the conventional dialysis population, it may be that sleep apnea contributes substantially to the sleepiness, poor quality of life, and cardiovascular disease found in this population. The causal links between conventional dialysis and sleep apnea remain speculative, but there are likely multiple factors related to volume status and azotemia that contribute to the high rate of severe sleep apnea in dialysis patients. Both nocturnal automated peritoneal dialysis and nocturnal hemodialysis have been associated with reduced severity of sleep apnea. Nocturnal dialysis modalities may provide tools to increase our understanding of the uremic sleep apnea and may also provide therapeutic alternatives for end-stage renal disease patients with severe sleep apnea. In conclusion, sleep apnea is an important, but overlooked, public health problem for the dialysis population. The impact of sleep apnea treatment in this high-risk population may include reduced sleepiness, better mood and blood pressure, and lowered risk of cardiovascular disease. [source]


    Smoking and hypoxemia caused by hepatopulmonary syndrome before and after liver transplantation

    HEPATOLOGY, Issue 2 2001
    Giovanni Rolla
    Severe hypoxemia may occur in patients with liver disease as a result of abnormal intrapulmonary vasodilatations (hepatopulmonary syndrome, HPS). Liver transplantation (LT) is the only effective treatment of HPS, with a quite variable delay of improvement of oxygenation. Smoking, by decreasing respiratory nitric oxide (NO), apparently contributed to improved oxygenation in a 44-year-old man with alcohol-induced cirrhosis, complicated by HPS, who underwent LT. The patient quit smoking just before LT, when his PaO2 was 29 mm Hg and exhaled NO (eNO) 28 ppb, a value far above the normal limits (9.6 ± 3.2 ppb). After LT, oxygenation remained poor and eNO remained high for more than 4 months, when the patient started to smoke again (blood HbCO going up to 5%). At that time eNO decreased to 6 ppb and PaO2 increased to 67 mm Hg. The strict relationship between eNO and oxygenation observed in this case reinforces the hypothesis that NO is the most important vasodilating mediator in HPS. Smoking may have hastened the resolution of HPS after LT by inhibiting respiratory NO and/or through a generalized impairment of endothelium-dependent vasodilation. [source]


    Scintigraphic evaluation of intrapulmonary shunt in normoxemic cirrhotic patients and effects of terlipressin

    HEPATOLOGY RESEARCH, Issue 10 2010
    George Kalambokis
    Aim:, The magnitude of intrapulmonary shunt (IPS) in cirrhotic patients without hypoxemia remains undefined. We evaluated the severity and clinical correlations of IPS in normoxemic cirrhotics, and possible IPS alterations after terlipressin treatment. Methods:, Fifteen patients with alcoholic cirrhosis without hypoxemia were studied at baseline and after the administration of 2 mg of terlipressin. The IPS fraction was evaluated by lung perfusion scan after the i.v. injection of technetium-99m -labeled macroaggregated albumin (99mTc-MAA) and calculation of brain uptake (positive value ,6%). Cardiac output (CO), pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR) were evaluated by Doppler echocardiography. Mean arterial pressure (MAP) was measured and the ratio MAP/CO was calculated as an index of systemic vascular resistance (SVR). Portal vein velocity (PVV) and portal venous flow (PVF) were also assessed by Doppler ultrasonography. Results:, Three patients (20%) had an IPS fraction of more than 6%. A significant inverse correlation with platelet count (P = 0.001) and a direct correlation with Child,Pugh score (P = 0.06), PVV (P = 0.07) and PVF (P = 0.07) were noted. IPS fractions decreased significantly after terlipressin administration (P = 0.00001); the IPS fraction fell below 6% in all three patients with positive baseline values. Terlipressin treatment induced a significant decrease in CO (P = 0.003) and significant increases in MAP (P = 0.0003), SVR (P = 0.0003), SPAP (P = 0.001) and PVR (P = 0.01). Conclusion:, IPS fractions detected by 99mTc-MAA lung scan were inversely correlated with platelet count and directly with liver disease severity, and found abnormal in 20% of normoxemic cirrhotic patients. Terlipressin reduced significantly the magnitude of the shunt. [source]


    Comparison of desaturation and resaturation response times between transmission and reflectance pulse oximeters

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2010
    S. J. CHOI
    Background: In general, there is a response time between actual arterial hypoxemia and its detection by pulse oximeters. We compared the desaturation and resaturation response times between two types of pulse oximeters, transmission and reflectance pulse oximeters, to find out which oximeter has a more rapid response time. Methods: Thirty-three ASA 1 or 2 patients were enrolled in this study. A transmission pulse oximeter was placed on the index finger and a reflectance pulse oximeter was placed on the forehead and monitored simultaneously. After the induction of general anesthesia without pre-oxygenation, we waited until the oxygen saturation value of any of two pulse oximeters declined to 90%, and then mask ventilation was started with 100% oxygen. Oxygen saturation was recorded at an interval of 2 s during this time. Results: The desaturation response time of SpO2 to 95% after apnea was 82.0 s (interquartile range: 67.0,98.5 s) vs. 94.0 s (interquartile range: 84.0,106.5 s) (P<0.001) and SpO2 to 90% was 94.0 s (interquartile range: 75.5,109.5 s) vs. 100.0 s (interquartile range: 84.5,114.5 s) (P<0.001) in the reflectance and transmission oximeters, respectively. The resaturation response time from mask ventilation to 100% SpO2 was 23.2±5.6 vs. 28.9±7.6 s (P<0.001) in the reflectance and transmission oximeters, respectively. Conclusion: In clinical situations in which rapid changes in oxygen saturation are expected, we recommend the forehead reflectance pulse oximeter because it responds more quickly in detecting oxygen desaturation and resaturation compared with the transmission pulse oximeter. [source]


    Sleep Apnea, Delirium, Depressed Mood, Cognition, and ADL Ability After Stroke

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2001
    Olov Sandberg MD
    OBJECTIVES: The incidence of sleep apnea and stroke increases with age. The aim of this study was to investigate the presence of sleep apnea after stroke and its relationship to delirium, depressed mood, cognitive functioning, ability to perform activities of daily living (ADLs), and psychiatric and behavior symptoms. DESIGN:Cross-sectional study. SETTING:Geriatric stroke rehabilitation unit. PARTICIPANTS:133 patients (78 women and 55 men, mean age 77.1 ± 7.7 years) consecutively admitted to a geriatric stroke rehabilitation unit. MEASUREMENTS: All patients underwent overnight respiratory sleep recordings at 23 ± 7 days (range 11 to 41 days) after suffering a stroke. The patients were assessed using the Organic Brain Syndrome Scale, Montgomery-Åsberg-Depression-Rating Scale, Mini-Mental State Examination (MMSE), and Barthel-ADL Index. Sleep apnea was defined as an apnea-hypopnea index (AHI) of 10 or more. RESULTS: The median of the AHI for the studied sample (N = 133) was 13 (range 0,79; interquartile range 6,28). Fifty-nine percent fulfilled the criteria for sleep apnea; 52% with first-ever stroke had sleep apnea. More patients with sleep apnea than without were delirious, depressed, or more ADL-dependent. Sleep apnea patients also had a higher frequency of ischemic heart disease and had more often suffered from an earlier cerebral infarction. Multivariate analysis showed that obesity, low ADL scores, ischemic heart disease, and depressed mood were independently associated with sleep apnea. Low ADL scores, apnea-related hypoxemia, body mass index ,27, and impaired vision were independently associated with delirium. The presence of sleep apnea was not associated with any specific type of stroke or location of the brain lesion. CONCLUSIONS:Sleep apnea is common in stroke patients and is associated with delirium, depressed mood, latency in reaction and in response to verbal stimuli, and impaired ADL ability. We suggest a trial investigating whether delirium, depressed mood, and ADL ability improve with nasal continuous positive airway pressure treatment of sleep apnea in stroke patients. [source]


    Anesthesia for Heart or Single or Double Lung Transplantation in the Adult Patient

    JOURNAL OF CARDIAC SURGERY, Issue 3 2000
    Paul M. Chetham M.D.
    Patients with end-stage cardiac dysfunction have an impaired response to ,-agonist due to receptor downregulation. These patient will have isolated left ventricular dysfunction secondary to ischemic heart disease or present with biventricular failure with or without significant pulmonary hypertension. Increasingly, more patients have undergone prior major cardiac procedures and are at risk for significant perioperative bleeding. Patients undergoing single or double lung are particularly challenging because most of these procedures are performed without the aid of cardiopulmonary bypass. The anesthesiologist must be proficient at the management of one-lung ventilation techniques and have a rational physiologic approach to the management of intraoperative hypoxemia and auto-PEEP. [source]


    Evolution of hypoxemia in patients with severe cirrhosis

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 10 2002
    Isabelle Colle
    Abstract Background and Aim: Hypoxemia is common in patients with cirrhosis but the natural history of this syndrome is unknown. The aim of this study was to follow a series of patients with cirrhosis and to compare patients with and without hypoxemia to determine their risk of complications and survival rate. Methods: Fifty-eight consecutive Child,Pugh C patients with cirrhosis were included and followed up for 1,18 months. Blood gas measurements and plasma endothelin levels were measured in all patients. Blood gas measurements were repeated in 34 patients. Results: Hypoxemia was present in 35 patients (60%) (alveolar-arterial oxygen (AaO2) gradient > 20 mmHg) but none had pulmonary symptoms. There was no significant difference in liver tests and plasma endothelin levels between hypoxemic and non-hypoxemic patients. The occurrence of variceal bleeding and survival rate was not significantly different between the two groups. The AaO2 gradient worsened in nine patients and normalized in six of the hypoxemic patients. The AaO2 gradient increased to more than 20 mmHg in seven non-hypoxemic patients. There was no relationship between AaO2 gradient changes and Child,Pugh score grade changes. Conclusion: Asymptomatic hypoxemia is common in patients with severe cirrhosis but it is not a predictive factor of short-term complications or mortality. These results should be considered when deciding on liver transplantation. [source]


    Conscious Sedation with Intermittent Midazolam and Fentanyl in Electrophysiology Procedures

    JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 2 2001
    F.A.C.C., ROMAN T. PACHULSKI M.D.
    Objectives: To determine the safety and efficacy of intermittent midazolam and fentanyl conscious sedation for electrophysiology procedures (EP). Background: Intermittent midazolam and fentanyl conscious sedation was administered in 700 consecutive cases (175 radiofrequency ablations, 163 EP studies, 261 pacemakers, and 101 implantable cardioverter-defibrillators) for 471 patients (239 males, 51%) mean age 65 ± 15 years. The mean dose of midazolam was 0.063 mg/kg/hr and fentanyl was 0.591,g/kg/hr. Methods: Cardiac rate and rhythm were monitored continuously, while blood pressure and arterial oxygen saturation were noninvasively assessed evevy 5 minutes. Drugs were administered in aliquots of 0.5 to 2.0 mg of midazolam and 6.25 to 25 ,g of fentanyl as determined by clinical condition every 15 to 30 minutes. Results: There were no deaths. In no case was endotracheal intubation required. Mild hypoxemia (SaO2 > 80%, but < 90%) occurred in 17 cases (2.4%) and was easily reversed with verbal stimulation and oropharyngeal repositioning (12 cases, 1.7%), increased F1O2 (3 cases, 0.4%), or intravenous naloxone (2 cases, 0.3%). Reversible hypotension (systolic blood pressure < 90, but > 60 mmHg) occurred in 14 patients (2.0%) and was corrected with intravenous crystalloid bolus or flumazenil (10 cases, 1.4%) or inotrope infusion (4 cases, 0.6%). No patient stay was prolonged due to sedation. Only five patients (0.7%) had any recollection of the procedure, while two (0.3%) were aware of pain. All hypoxemic episodes occurred during the first hour, whereas 43% (6/14) of hypotensive episodes occurred after the first hour. Conclusion: Conscious sedation with intermittent midazolam and fentanyl is safe and eficacious for a broad range of EP procedures. (J Interven Cardiol 2001; 14:143,146) [source]


    SHORTNESS OF BREATH DURING DIALYSIS,A ROLE OF BICARBONATE IN DIALYSIS FLUID?

    JOURNAL OF RENAL CARE, Issue 1 2008
    Karen Latchford BSN
    SUMMARY Occasionally dialysis patients show symptoms that indicate intolerance in the way dialysis is delivered. This paper describes two cases of transient shortness of breath during the initial treatments after starting online haemodiafiltration (HDF). Our actions to deal with these symptoms focused on reducing the bicarbonate gain during the first phase of the dialysis treatment. As the symptoms gradually disappeared we hypothesise that the bicarbonate concentration in the dialysis fluid may play an important role for the development of shortness of breath and hypoxemia during HDF treatments. [source]


    N-terminal pro-brain natriuretic peptide for detection of cardiovascular stress in patients with obstructive sleep apnea syndrome

    JOURNAL OF SLEEP RESEARCH, Issue 4 2006
    EDMOND VARTANY
    Summary Patients with obstructive sleep apnea syndrome (OSAS) have an elevated incidence of cardiovascular events that may be related to an increased ventricular load and hypoxemia caused by apneas and hypopneas. N-terminal pro-brain natriuretic peptide (NTproBNP) appears to be an excellent marker of myocardial stretch and could serve as an indicator of subclinical cardiac stress, thereby identifying a patient population at risk for cardiac effects from OSAS. Adult patients presenting with suspected OSAS and scheduled for nocturnal polysomnography were recruited. Patients with heart or renal failure or severe lung disease were excluded. NTproBNP was measured the evening before and the morning after sleep. Blood pressure (BP) was monitored intermittently throughout the night. Fifteen male and 15 female subjects with a mean ± SD body mass index of 38.2 ± 9.8 were studied. Mean Apnea,Hypopnea Index (AHI) was 38.4 ± 26, with 17 subjects having severe OSAS (AHI > 30). No subject had a significant rise in BP. NTproBNP values overnight decreased in 19 patients and rose in 11 (mean change 3.8 ± 33 pg mL,1), but only one patient had an abnormal morning value. Three patients had an abnormal NTproBNP value prior to sleep, but their levels decreased with sleep. No correlations were detected between the evening baseline or postsleep NTproBNP levels and OSAS. Monitoring pre- and postsleep NTproBNP levels revealed no association with the occurrence or degree of OSAS, making it unlikely that NTproBNP could serve as a marker of cardiac stress in OSAS patients with stable BP and without overt heart failure. [source]


    Divergent effects of ephedrine and phenylephrine on cardiovascular hemodynamics of near-term fetal sheep exposed to hypoxemia and maternal hypotension

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2007
    T. Erkinaro
    Background:, We hypothesized that the administration of ephedrine and phenylephrine for maternal hypotension modifies cardiovascular hemodynamics in near-term sheep fetuses. Methods:, At 115,136 days of gestation, chronically instrumented, anesthetized ewes with either normal placental function or increased placental vascular resistance after placental embolization were randomized to receive boluses of ephedrine (n = 12) or phenylephrine (n = 12) for epidural-induced hypotension after a short period of hypoxemia. Fetal cardiovascular hemodynamics were assessed by Doppler ultrasonography at baseline, during hypotension and after vasopressor treatment. Results:, During hypotension, fetal PO2 decreased and proximal branch pulmonary arterial and pulmonary venous vascular impedances increased. Additionally, in the embolized fetuses, the time-velocity integral ratio between the antegrade and retrograde blood flow components of the aortic isthmus decreased. These parameters were restored to baseline conditions by ephedrine but not by phenylephrine. With phenylephrine, weight-indexed left ventricular cardiac output and ejection force decreased in the non-embolized fetuses, and the proportion of isovolumetric contraction time of the total cardiac cycle was elevated in the embolized fetuses. Conclusions:, After exposure to hypoxemia and maternal hypotension, ephedrine restored all fetal cardiovascular hemodynamic parameters to baseline. Phenylephrine did not reverse fetal pulmonary vasoconstriction or the relative decrease in the net forward flow through the aortic isthmus observed in fetuses with increased placental vascular resistance. Moreover, fetal left ventricular function was impaired during phenylephrine administration. [source]


    Pilot study of pentoxifylline in hepatopulmonary syndrome,

    LIVER TRANSPLANTATION, Issue 8 2008
    Rajasekhar Tanikella
    Hepatopulmonary syndrome (HPS) results when chronic liver disease or portal hypertension causes intrapulmonary microvascular dilatation with hypoxemia. In experimental HPS, tumor necrosis factor alpha (TNF-,) overproduction contributes to vasodilatation, which is improved by pentoxifylline, a TNF-, inhibitor. The effectiveness of pentoxifylline in humans is unknown. The aim of this open-label, single-arm clinical trial was to assess the efficacy and tolerability of pentoxifylline in patients with cirrhosis and advanced HPS undergoing liver transplantation evaluation. Nine adults with cirrhosis and moderate to severe HPS were enrolled. All patients had an initial 2-week titration to a target dose of pentoxifylline of 400 mg by mouth every 8 hours, which was continued for 6 weeks. Baseline and follow-up arterial blood gases and TNF-, levels were evaluated. Adverse effects and tolerability were assessed. The 9 patients had a mean age of 55 ± 10 years, and 67% were female. The most common causes of cirrhosis were hepatitis C virus and alcohol (55%). The mean Model for End-Stage Liver Disease score was 11 (range, 6-19), and patients had advanced hypoxemia [mean partial pressure of arterial oxygen (PaO2) = 54 ± 12 mm Hg, mean alveolar-arterial oxygen gradient (A-a PaO2) = 57 ± 15 mm Hg]. Of the 9 patients enrolled, follow-up blood gases were done in 7. There was no significant change in PaO2 (P = 0.3) or A-a PaO2 (P = 0.3) with treatment. Pentoxifylline was poorly tolerated. Nausea (100%) and vomiting (56%) were the predominant side effects, and only a single patient was able to complete full-dose therapy. Treatment with pentoxifylline did not improve arterial oxygenation in advanced HPS, and tolerance was limited by gastrointestinal toxicity. Liver Transpl 14:1199,1203, 2008. © 2008 AASLD. [source]


    Cost-effectiveness of screening for hepatopulmonary syndrome in liver transplant candidates,

    LIVER TRANSPLANTATION, Issue 2 2007
    D. Neil Roberts
    The hepatopulmonary syndrome (HPS) is present in 15,20% of patients with cirrhosis undergoing orthotopic liver transplantation (OLT) evaluation. Both preoperative and post-OLT mortality is increased in HPS patients particularly when hypoxemia is severe. Screening for HPS could enhance detection of OLT candidates with sufficient hypoxemia to merit higher priority for transplant and thereby decrease mortality. However, the cost-effectiveness of such an approach has not been assessed. Our objective was to perform a cost-effectiveness analysis from a third-party payer's perspective of screening for HPS in liver OLT candidates. The costs and outcomes of 3 different strategies were compared: (1) no screening, (2) screening patients with a validated dyspnea questionnaire, and (3) screening all patients with pulse oximetry. Arterial blood gas analyses and contrast echocardiography were performed in patients with dyspnea or a pulse oximetry (SpO2) ,97% to define the presence of HPS. A Markov model was constructed simulating the natural history of cirrhosis in a cohort of patients 50 years old over a time horizon of their remaining life expectancy. Transition probabilities were obtained from published data available through Medline and U.S. vital statistics. Costs represented Medicare reimbursement data at our institution. Costs and health effects were discounted at a 3% annual rate. No screening was associated with a total cost of $291,898 and a life expectancy of 11.131 years. Screening with pulse oximetry was associated with a cost of $299,719 and a life expectancy of 12.27 years. Screening patients with the dyspnea-fatigue index was associated with a cost and life expectancy of $300,278 and 12.28 years, respectively. The incremental cost-effectiveness ratio of screening with pulse oximetry (compared to no screening) was $6,867 per life year gained, whereas that of the dyspnea-fatigue index (compared to pulse oximetry) was $55,900 per life year gained. The cost-effectiveness of screening depended on the prevalence and severity of HPS, and the choice of screening strategy was dependent on the sensitivity of the screening modality. In conclusion, screening for HPS, especially with pulse oximetry, is a cost-effective strategy that improves survival in transplant candidates predominantly by targeting the transplant to the subgroup of patients most likely to benefit. The utility of screening depends on the prevalence and severity of HPS in the target population. Liver Transpl, 2006. © 2006 AASLD. [source]


    Pulmonary gas exchange abnormalities in liver transplant candidates

    LIVER TRANSPLANTATION, Issue 9 2002
    Rosmawati Mohamed
    Abnormal diffusing capacity is the commonest pulmonary dysfunction in liver transplant candidates, but severe hypoxemia secondary to hepatopulmonary syndrome and significant pulmonary hypertension are pulmonary vascular manifestations of cirrhosis that may affect the perioperative course. We prospectively assessed the extent of pulmonary dysfunction in patients referred for liver transplantation. A total of 57 consecutive patients with chronic liver disease were evaluated. All patients had a chest radiograph, standing arterial blood gas on room air, pulmonary function testing, and Doppler echocardiogram. Those patients with arterial hypoxaemia (PaO2 < 10 kPa) also underwent 99mTc-macroaggregated albumin lung scan, and nine patients had agitated normal saline injection during echocardiography to define further the existence of pulmonary vascular dilatation. Reduced diffusing capacity for carbon monoxide less than 75% of the predicted value was found in 29 of 57 (51%) patients. Although elevated alveolar-arterial oxygen tension difference was detected in 35% (20/57) of the patients, only four (7%) patients had hypoxemia. We were unable to find evidence of intrapulmonary vascular dilatation either on the lung scan or saline-enhanced echocardiography in any of these patients. Reduction in diffusing capacity for carbon monoxide was noted in 75% (18/24) of patients who were transplanted for primary biliary cirrhosis and was accompanied by widened alveolar-arterial oxygen tension in 10 out of 18 (56%) of patients. This study shows that in liver transplant candidates, diffusion impairment and widened alveolar-arterial oxygen tension difference were frequently detected, especially in patients with primary biliary cirrhosis. [source]


    Utility of pulse oximetry in the detection of arterial hypoxemia in liver transplant candidates

    LIVER TRANSPLANTATION, Issue 4 2002
    Gary A. Abrams MD Assistant Professor of Medicine
    Hepatopulmonary syndrome, arterial hypoxemia caused by intrapulmonary vasodilatation, occurs in approximately 10% of patients with cirrhosis. The severity of hypoxemia affects liver transplant candidacy and is associated with increased morbidity and mortality posttransplantation. Screening guidelines for detecting the presence of arterial hypoxemia do not exist. The aim of this study is to investigate the accuracy and utility of pulse oximetry in the detection of hypoxemia (PaO2 < 70 mm Hg) in patients with cirrhosis. Two hundred prospective liver transplant candidates were compared with 94 controls. Arterial oxyhemoglobin saturation was obtained by pulse oximetry (SpO2) and compared with simultaneous arterial blood gas (ABG) oxyhemoglobin values (SaO2; bias = the difference). PaO2, carboxyhemoglobin, methemoglobin, and routine clinical and biochemical parameters were investigated to account for the bias. SpO2 overestimated SaO2 in 98% of patients with cirrhosis (mean bias, 3.37%; range, ,1% to 10%). Forty-four percent of patients with cirrhosis and controls had a bias of 4% or greater. No clinical or biochemical parameters of cirrhosis accounted for the overestimation of pulse oximetry. Twenty-five subjects with cirrhosis were hypoxemic, and an SpO2 of 97% or less showed a sensitivity of 96% and a positive likelihood ratio of 3.9 for detecting hypoxemia. An SpO2 of 94% or less detected all subjects with an arterial PaO2 less than 60 mm Hg. Pulse oximetry significantly overestimates arterial oxygenation, and the inaccuracy is not influenced by liver disease. Nevertheless, pulse oximetry can be a useful screening tool to detect arterial hypoxemia in patients with cirrhosis, but a higher threshold for obtaining an ABG must be used. [source]


    Bilateral occipital neuropathy as a rare complication of positioning for thyroid surgery in a morbidly obese patient

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2004
    S. Schulz-Stübner
    Background:, Peripheral neuropathies in various locations are described as complications after anesthesia and surgery. This is the first case report of temporary bilateral occipital neuropathy from positioning for thyroid surgery in a morbidly obese patient. Methods:, A 48-year-old women with a history of depression, fibro-myalgia, asthma, sleep apnea, diabetes mellitus and morbid obesity (127 kg, 165 cm) underwent 4 hours anesthesia with propofol/remifentanil without muscle relaxation for thyroid surgery. The neck with a very low range of motion secondary to fat tissue needed to be extended to facilitate surgery as much as possible. The head was carefully padded and there were no episodes of hypotension or hypoxemia throughout the case or in the PACU. At post op day 1 she complained of bilateral numbness in the distribution area of both greater occipital nerves. On post op day 2 tingling sensations and improvement of numbness was noticed. The patient recovered without residual symptoms after 6 weeks. Conclusion:, Pressure or shear stress to the nerve, hypoperfusion or metabolic disturbances are discussed as the leading etiology of nerve damage during surgery in the literature. Pressure from fat tissue during prolonged head extension for surgery seems to be the cause in this case and should therefore be avoided whenever possible in morbidly obese patients, especially when other risk factors for neuropathy like diabetes are present. [source]


    Bilateral pulmonary edema after endoscopic sympathectomy in a patient with glucose-6-phosphate dehydrogenase deficiency

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2001
    C.-J. Lan
    Transaxillary endoscopic sympathectomy of thoracic ganglia (T2,T3) has recently gained wider acceptance as the treatment of choice for palmar hyperhidrosis. It requires one-lung ventilation to facilitate the surgery. One-lung ventilation, however, is not without complications, among which acute pulmonary edema has been reported. In this case report, we present a patient with palmar hyperhidrosis complicated by glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, who received bilateral endoscopic sympathectomy under alternate one-lung anesthesia, and developed acute pulmonary edema immediately after recruitment of the successive collapsed lung. The effects of hypoxemia, G-6-PD deficiency and sympathectomy might all add to the development of acute pulmonary edema secondary to reexpansion of each individual lung after alternate one-lung ventilation. The possibilities of the inferred causes are herein discussed. [source]


    Presurgical fentanyl vs caudal block and the incidence of adverse respiratory events in children after orchidopexy

    PEDIATRIC ANESTHESIA, Issue 12 2009
    SAMIA N. KHALIL MD
    Summary Background:, There is controversy about the etiology of early postoperative hypoxemia. Age, weight, intubation, surgical procedure, use of muscle relaxants, and/or administration of opioids may affect the incidence of early postoperative hypoxemia. In this prospective, randomized, and single-blinded study, we evaluated whether the administration of caudal analgesia vs i.v. fentanyl affected the number of children who develop postextubation adverse upper airway respiratory events, (upper airway obstruction, laryngospasm) and/or early postoperative hypoxemia. Methods/materials:, Institutional approval and written parental informed consents were obtained. Thirty-eight healthy outpatient boys, aged 1,6 years, scheduled for elective orchidopexy were randomized to receive pain relief either with a presurgical caudal block or by i.v. fentanyl. The primary outcome of the study was the number of children who developed postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia. Results:, The number of boys who developed postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia in the caudal group was less compared with those in the fentanyl group (P = 0.04). Conclusions:, Compared to fentanyl, placement of a presurgical caudal block in boys scheduled for orchidopexy was associated with a lower incidence of postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia. [source]


    ProSealTM laryngeal mask airway in 120 pediatric surgical patients: a prospective evaluation of characteristics and performance

    PEDIATRIC ANESTHESIA, Issue 3 2006
    MELISSA WHEELER MD
    Summary Background:, The ProSealTM LMA (PLMATM) has recently been introduced in pediatric sizes (1.5, 2, 2.5, 3). Limited pediatric data have been published. Methods:, After Institutional Review Board (IRB) approval, the PLMATM was placed in 120 children aged 4 months to 13 years (5,50 kg). The following data were collected prospectively: induction agent, number of placement attempts (limited to three), placement success or failure, PLMATM size, leak pressure, ventilatory pattern [spontaneous (SV) or controlled positive pressure ventilation (PPV)], success or failure of gastric suction tube placement, hypoxemia, dislodgement, laryngospasm, bronchospasm, aspiration, and traumatic placement. Results:, The PLMATM was easily placed in children with a higher first attempt success rate (94%) than reported for adults. Overall PLMATM and gastric tube placement were both 100% successful. Leak pressures were similar to those reported for the PLMATM in adults and higher than reported for the ClassicTM LMATM in children. No bronchospasm, laryngospasm, hypoxemia, dislodgement, or aspiration occurred. Conclusions:, Although the PLMATM can be used with SV or PPV, the higher leak pressure achieved with the PLMATM, and the ability to evacuate fluid and air from the stomach suggest that it may be a useful alternative to tracheal intubation for procedures in which PPV is desired in children aged 4 months to 13 years. [source]


    Familial neuroendocrine cell hyperplasia of infancy,,

    PEDIATRIC PULMONOLOGY, Issue 8 2010
    J. Popler MD
    Abstract Background Neuroendocrine cell hyperplasia of infancy (NEHI) is a recently described children's interstitial lung disease (chILD) disorder of unknown etiology. It manifests clinically with tachypnea, retractions, hypoxemia, and crackles. The characteristic radiographic appearance consists of pulmonary hyperexpansion and ground-glass densities on high-resolution computed tomography (HRCT). Lung histology shows hyperplasia of bombesin-immunopositive neuroendocrine cells within distal bronchioles and alveolar ducts without other identifiable lung pathology or developmental anomaly. Methods We describe four families with multiple siblings diagnosed with NEHI. Cases were identified at three pediatric centers. Inclusion criteria included clinical findings consistent with NEHI, lung biopsy confirmation in the index case, and a diagnostic HRCT or biopsy in other siblings. Results Each family had a proband diagnosed with NEHI based upon pathologic review, and at least one additional sibling diagnosed either by pathologic review or HRCT. All patients presented between 2 and 15 months of age. Both male and female children were affected. The majority of the patients underwent both HRCT and lung biopsy. There were no deaths among affected children. No environmental exposures or other potential etiologies were identified as a cause of presenting symptoms. Conclusions The familial occurrence of NEHI suggests the possibility of a genetic etiology for this disorder and highlights the importance of taking a complete family medical history for infants presenting with a suggestive clinical picture. Identification of familial NEHI patients allows for the opportunity to further our understanding of this disorder, its natural history, the phenotypic spectrum, and potential genetic causes. Pediatr. Pulmonol. 2010; 45:749,755. © 2010 Wiley-Liss, Inc. [source]


    Acute pulmonary toxicity following intralesional administration of bleomycin for a lymphovenous malformation

    PEDIATRIC PULMONOLOGY, Issue 2 2010
    Khalid Atwa MD
    Abstract Objective To describe the clinical course and treatment of an infant with acute pulmonary toxicity following intralesional administration of bleomycin for a lymphovenous malformation. Design Case report. Setting A tertiary care University-affiliated hospital. Patient, Intervention, and Results An 8-month-old girl developed acute respiratory distress with profound hypoxemia complicated by pneumothorax and pneumomediastinum 1 day following intralesional administration of bleomycin. She was treated with bilateral chest tube insertion, systemic corticosteroids, pentoxifylline, and supportive care. At the most recent follow-up 5 months after the onset of the respiratory event, the patient is active, walks, and talks without any evidence of pulmonary diseases clinically. This is the youngest infant reported, to date, with acute bleomycin pulmonary toxicity following intralesional administration of bleomycin resulting in acute respiratory insufficiency followed by complete recovery. Conclusions This case illustrates the importance of early recognition and aggressive treatment of acute bleomycin toxicity resulting from intralesional administration of this medication for lymphovenous malformations. Pediatr Pulmonol. 2010; 45:192,196. © 2009 Wiley-Liss, Inc. [source]


    Rituximab (B-cell depleting antibody) associated lung injury (RALI): A pediatric case and systematic review of the literature

    PEDIATRIC PULMONOLOGY, Issue 9 2009
    Martin Bitzan MD
    Abstract Introduction Pulmonary toxicity of delayed onset is a rare complication of B-lymphocyte depleting antibody therapy and has been almost exclusively reported in older patients with B-cell malignancies. Aims To describe a pediatric patient with rituximab-associated lung injury (RALI), to systematically analyze previous reports of pulmonary complications, and to summarize common clinico-pathological features, treatment, and outcome. Results A teenage boy with focal segmental glomerulosclerosis (FSGS) presented with progressive dyspnea, fever, hypoxemia and fatigue 18 days after the completion of a second course of rituximab infusions for calcineurin inhibitor-dependent nephrotic syndrome. Respiratory symptoms started while he received high-dose prednisone for persistent proteinuria. Bilateral, diffuse ground-glass infiltrates corresponded to the presence of inflammatory cells in the bronchioalveolar lavage fluid. Empiric antibiotic treatment including clarithromycin was given, but the microbiological work-up remained negative. Serum IgE, C3, and C4 concentrations were normal. He recovered within 3 weeks after onset. We systematically reviewed 23 reports describing 30 additional cases of rituximab-associated lung disease. Twenty eight patients had received rituximab for B-cell malignancies, one for graft-versus-host disease and one for immune thrombocytopenia. Median age was 64 years (interquartile range [IQR] 58,69 years). Seventy one percent received concomitant chemotherapy. Time to onset from the last rituximab dose was 14 days (IQR 11,22 days). Eleven of 31 patients required mechanical ventilation, and 9 died (29%). Ventilation was a significant predictor of fatal outcome (odds ratio 46.7; confidence interval 9.5,229.9). High dose glucocorticoid therapy did not improve survival or prevent severe lung disease or death. Conclusions With the expanding use of rituximab for novel indications, additional cases of RALI affecting younger age groups are expected to emerge. Mechanical ventilation predicts poor outcome. Glucocorticoids may not be protective. Pediatr Pulmonol. 2009; 44:922,934. © 2009 Wiley-Liss, Inc. [source]


    Episodes of hypoxemia during synchronized intermittent mandatory ventilation in ventilator-dependent very low birth weight infants

    PEDIATRIC PULMONOLOGY, Issue 1 2005
    Steve R.E. Firme MD
    Abstract Distinct patterns of asynchrony, and episodes of hypoxemia, may occur in a spontaneously breathing preterm infant during conventional intermittent mandatory ventilation (IMV) on traditional time-cycled, pressure-limited ventilators. Synchronized IMV (SIMV) and assist/control ventilation are frequent modes of patient-triggered ventilation used with infant ventilators. The objective of this study was to use computerized pulse oximetry to quantify the occurrence of episodes of hypoxemia (oxygen desaturation) during SIMV vs. IMV, in preterm infants ,1,250 g who required mechanical ventilation at ,14 days of age. We performed a randomized, crossover study with each infant being randomized to IMV or SIMV (Infant Star ventilator) for initial testing for a 1-hr period. Patients were subsequently tested on the alternate modality after a stabilization period of 10 min at the same ventilator and fractional inspired oxygen concentration (FiO2) settings. Pulse oximetry data were obtained with a Nellcor N-200 monitor, a microcomputer, and a software program (SatMaster). An investigator blinded to the randomized assignment evaluated all measurements. Eighteen very low birth weight (VLBW) infants with a birth weight of 777,±,39 g (mean,±,SEM) and gestational age 25.1,±,0.3 weeks were studied. The average pulse oximeter oxygen saturation (SaO2) was higher on SIMV than IMV (P,<,0.01). During SIMV, these infants had significantly fewer episodes of hypoxemia (duration of episodes of oxygen desaturation as a percentage of scorable recording time) to 86,90% SaO2 (P,<,0.01), 81,85% SaO2 (P,<,0.01), and 76,80% SaO2 (P,<,0.05) when compared to IMV. There was also a significant decrease in percentage of time of desaturation to SaO2,<,90% (P,=,0.002),,<,85% SaO2 (P,=,0.003), and <80% SaO2 (P,=,0.02) during SIMV vs. IMV. Our preliminary findings indicate that the use of SIMV in a population of VLBW ventilator-dependent infants (,14 days of age) results in better oxygenation and decreased episodes of hypoxemia as compared to IMV. © 2005 Wiley-Liss, Inc. [source]