Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients with restrictive lung disease, owing to respiratory muscle dysfunction, have no parenchymal involvement. Their vital capacity (VC) and total lung capacity (TLC) are reduced to less than 50% and can lead to pneumonia and nocturnal hypercapnia and hypoxia. Their diffusion capacity is normal. With maximal static mouth pressure (Pimax) < 80 cm H2O and/or Pemax < 100 cm H2O, patients are referred to the national centres. Here, inspiratory muscular insufficiency is confirmed by sniff nasal inspiratory pressure and oesophageal pressure < 70 cm H2O. Expiratory muscular insufficiency is confirmed by a cough peak flow < 3-4 L/sec. and cough gastric pressure < 100 cm H2O. Sleep studies reveal nocturnal hypoventilation. Phrenic nerve stimulation is to be introduced in the diagnostic approach. Twitch mouth or oesophageal pressure < 10 cm H2O and twitch gastric pressure < 7 cm H2O are pathognomonic for neuromuscular respiratory insufficiency.
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PMID:[Hypodynamic respiratory insufficiency. Diagnostic investigation]. 1252 42

Respiratory network plasticity is a modification in respiratory control that persists longer than the stimuli that evoke it or that changes the behavior produced by the network. Different durations and patterns of hypoxia can induce different types of respiratory memories. Lateral pontine neurons are required for decreases in respiratory frequency that follow brief hypoxia. Changes in synchrony and firing rates of ventrolateral and midline medullary neurons may contribute to the long-term facilitation of breathing after brief intermittent hypoxia. Long-term changes in central respiratory motor control may occur after spinal cord injury, and the brain stem network implicated in the production of the respiratory rhythm could be reconfigured to produce the cough motor pattern. Preliminary analysis suggests that elements of brain stem respiratory neural networks respond differently to hypoxia and hypercapnia and interact with areas involved in cardiovascular control. Plasticity or alterations in these networks may contribute to the chronic upregulation of sympathetic nerve activity and hypertension in sleep apnea syndrome and may also be involved in sudden infant death syndrome.
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PMID:Invited review: Neural network plasticity in respiratory control. 1257 Nov 45

Non-invasive positive pressure ventilation (NIPPV) has been discussed comprehensively in the last years, but usage of non-invasive ventilation in Intensive Care Units is rare. The reasons may be uncertainty in indications and difficulties in handling the masks and ventilators. In the last years the introduction of full face masks and respiratory helmets has made it possible to ventilate patients with unusual facial forms and to avoid problems of pressure necrosis. Software components designed for NIPPV are available for standard respirators. Indications for NIPPV (neuromuscular diseases, spinal abnormalities, chest wall malformations, COPD, cardiogenic pulmonary edema) have been ensured in clinical trials. No sufficient data are available for the application of NIPPV in weaning and respiratory failure following extubation. Indication for NIPPV becomes apparent when therapy starts in early stage with sufficient ventilation pressure. Compared to standard therapy, no reliable advantage has been seen for NIPPV in hypoxic hypercapnia respiratory failure except for malignant diseases. However, prophylactic use in patients with high risk might be conceivable. For these patients strict criteria of termination are required to avoid missing the time point for intubation. Gas exchange disturbances in advanced lung fibrosis, pneumonia and ARDS are not amenable to NIPPV. Contraindications for NIPPV are non-compliant patients, absence of cough- and pharyngeal reflexes as well as retention of secretions and malignant ventricular arrhythmia. Relative contraindications are catecholamine-dependent circulatory collapse and acute myocardial infarction, since sufficient data for NIPPV are missing.
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PMID:[Noninvasive ventilation in the intensive care unit -- is it still negligible?]. 1267 84

Congenital lobar emphysema (CLE) is characterized by overdistension and air-trapping in the affected lobe, and is one of the causes of infantile respiratory distress. In this report, we review our 27 years of experience with 30 CLE patients. Patients' medical records were evaluated with regard to age, clinical presentation, diagnostic methods, associated diseases, treatment, histopathologic findings, and final clinical and laboratory findings at the end of a long-term period. The mean age of 30 patients (18 male) at diagnosis was 4.9 +/- 6.7 months (range, 2 days-2.5 years). Tachypnea, dyspnea, cough, cyanosis, wheezing, hoarseness, and decreased breath sounds on the affected side were the main symptoms and clinical findings. On chest X-rays, emphysema was seen in all patients; shift/herniation to the opposite lung, atelectasis, and pneumothorax were observed in 16, 5, and 2 cases, respectively. Computerized tomography of the thorax was performed in 16 cases and revealed emphysema at affected lobe/lobes in all, a shift/herniation to the opposite side in 12 cases, and atelectasis of neighbor lobe/lobes in 7 cases. All 8 patients who had perfusion scintigraphy showed reduced perfusion in the affected lobe. Narrowed and flaccid bronchi were detected in one patient by using flexible bronchoscopy. Blood gas analysis was performed in 11 patients, and hypoxia and hypercarbia were revealed in 9 and 7 of these patients, respectively. The most common affected lobe was the left upper lobe (57%), followed by the right upper lobe (30%) and right middle lobe (27%). Two lobes were involved in 4 patients. Associated abnormalities were observed in 5 patients. Twenty-one patients underwent lobectomy; 9 were followed conservatively. Ages at diagnosis were significantly younger in surgically treated patients. Emphysema was detected in all pathological specimens, with an additional bronchial cartilage deficiency in 2 patients. In the surgically treated group, 2 patients died and 2 patients were lost to follow-up. In the conservatively treated group, one patient was lost to follow-up. Mean follow-up duration of all patients was 63.2 +/- 56.2 months (range, 1-209 months). At follow-up visits, all patients were doing well. In surgically treated patients, chest X-rays were normal (9 cases), or showed hyperlucency on the operated side (6 cases) or chronic changes in the operation area (2 cases). Hyperexpansion in the affected lobe was found to be reduced in all cases in the conservatively treated group.
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PMID:Congenital lobar emphysema: evaluation and long-term follow-up of thirty cases at a single center. 1268 96

The cerebellum contains three deep nuclei, i.e., the fastigial, interposed and lateral nucleus. Recent studies demonstrate that these nuclei play different roles in respiratory modulation. Activation of fastigial nuclear neurons predominantly increases ventilation via elevation of respiratory frequency and/or tidal volume. Ablation of the fastigial nucleus did not significantly alter eupneic breathing, but did markedly attenuate the respiratory response to medium and severe hypercapnia as well as hypoxia. The fastigial nucleus contains respiratory-modulated neurons and about 25% of these neurons do not show their respiratory-related phasic activity until exposed to hypercapnia. The fastigial nucleus also contains CO2/H+ chemosensitive sites that contributed to the respiratory response to hypercapnia. Therefore, it is concluded that fastigial nuclear facilitatory influence on chemoreflexes emerges during hypercapnia via recruiting intrinsic chemoreception and respiratory-modulated neurons. Full expression of the fastigial nucleus-mediated respiratory responses depends on the integrity of the medullary gigantocellular nucleus at least partially via monosynaptic projections. Additionally, the fastigial nucleus receives inhibitory inputs primarily from Purkinje cells located in the medial vermis and recent observations indicate that simulation of these Purkinje cells inhibits respiration. As compared to chemoreflexes, fastigial nuclear role in the respiratory mechanoreflexes is not significant. The studies related to the role of the interposed and lateral nucleus in eupneic breathing are limited and the results appear controversial. However, there is evidence to show that the interposed nucleus contains respiratory-modulated neurons and is involved in coughing motor control.
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PMID:Role of the cerebellar deep nuclei in respiratory modulation. 1287 68

We reasoned that, if the lung inflation reflex contributes importantly to apnea-induced sympathetic activation, such activation would be attenuated in bilateral lung transplant recipients (LTX). We measured muscle sympathetic nerve activity (MSNA; intraneural electrodes), heart rate, mean arterial pressure, tidal volume, end-tidal Pco(2), and arterial oxygen saturation in seven LTX and seven healthy control subjects (Con) before, during, and after 20-s end-expiratory breath holds. Our evidence for denervation in LTX was 1) greatly attenuated respiratory sinus arrhythmia and 2) absence of cough reflex below the level of the carina. During apnea, the temporal pattern and the peak increase in MSNA were virtually identical in LTX and Con (347 +/- 99 and 359 +/- 46% of baseline, respectively; P > 0.05). In contrast, the amount of MSNA present in the first 5 s after resumption of breathing was greater in LTX vs. Con (101 +/- 4 vs. 38 +/- 7% of baseline, respectively; P < 0.05). There were no between-group differences in apnea-induced hypoxemia or hypercapnia, hemodynamic, or ventilatory responses. Thus cessation of the rhythmic sympathoinhibitory feedback that normally accompanies eupneic breathing does not contribute importantly to sympathetic excitation during apnea. In contrast, vagal afferent input elicited by hyperventilation-induced lung stretch plays an important role in the profound, rapid sympathetic inhibition that occurs after resumption of breathing after apnea.
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PMID:Role of sensory input from the lungs in control of muscle sympathetic nerve activity during and after apnea in humans. 1507

We investigated neuro-respiratory function of a 60-year-old woman with a 7-year-history of amyotrophic lateral sclerosis. She was trachomized 4 years ago, however, spontaneous respiration had been observed. Plethysmography disclosed autonomous and abolished volitional control on breathing. Cough reflex and emotional laughing influenced on respiration pattern. Positive reaction of respiration to hypercapnia was observed. Then, it seemed to be preserved respiratory neurons in the medulla oblongata and bulbospinal tract, and remarkable impairement of the corticospinal tract.
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PMID:[Selective volitional respiration control loss (inverse Ondiene's curse syndrome) in amyotrophic lateral sclerosis]. 1550 36

Bronchoscopic lung volume reduction is a novel approach to the treatment of severe emphysema. Its objective is to achieve the same improvements in lung function and exercise tolerance as lung volume reduction surgery while avoiding the surgical morbidity and mortality. We describe the anesthetic experience in a series of seven patients who underwent a total of eight procedures (one patient underwent a second procedure on the contralateral side). The technique used was one of total IV anesthesia using remifentanil and propofol, with a ventilatory strategy aimed at avoiding gas trapping and dynamic hyperinflation. To achieve this pressure, limited ventilation with a prolonged expiratory phase was provided by a Draeger Evita 2 ventilator. This technique resulted in intraoperative hypercapnia (Paco(2) 6.75 kPa) compared with baseline values (median Paco(2) 5.1 kPa; P < 0.05), but 2 h postoperatively the arterial partial pressure of CO(2) was returning to baseline (median Paco(2) 5.6 kPa; P < 0.01 compared with intraoperative data). There were no deaths or admissions to the intensive care unit after the procedure. One patient developed a pneumothorax that required drainage, three patients had acute exacerbations of chronic obstructive pulmonary disease, and one patient developed a cough that resolved spontaneously. Total hospital stay did not exceed 5 days for any of these patients.
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PMID:Bronchoscopic lung volume reduction in patients with severe emphysema: anesthetic management. 1556 41

The authors report the results of a study on patients with chronic cor pulmonale hospitalized in the Departement of Cardiology (Dakar), from 1990 to 1998. The hospital prevalence is 0.9% with a male predominance (73.5%). The clinical signs were dominated by dyspnea and cough. The right heart failure is noted in 85.29% of cases. As far as the biological factor is concerned, it exists an polycythemia about 75% of cases, hypoxia (88.8%), hypercapnia (55.5%) and a respiratory acidoses (55.5%). The spirometry showed in 66% of cases, a mixed syndrom with obstructive predominance. The echocardiography showed in all cases right heart dilatation with pulmonary hypertension. The etiological factors are dominated by tobacco (21 cases). The hospital evolution has been favorable in 19 cases underoxygentherapy, lowdosediuretic, expectorant, bronchodilatators and salt restriction. However, 14 patients have died.
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PMID:[Chronic cor pulmonale: a study of 34 cases in the Dakar University Hospital Center Cardiology Department]. 1577 62

Recent clinical studies have emphasized the up-regulation (sensitization) of cough in pathological conditions of the airways. However there are also many situations where voluntary and reflex cough can be down-regulated. These include: (1) chemical stimulation of breathing by hypercapnia or hypoxia or both, establishing that cough sensitivity can be inversely related to drive to breathing; (2) voluntary inhibition of cough, probably similar in mechanism to the depression of cough that can be induced by hypnosis and other branches of alternative medicine; (3) the placebo effect of many antitussive treatments; (4) sleep; (5) general anaesthesia; (6) central nervous disorders such as coma, stroke, Parkinson's disease and several other conditions where the defect in the protective reflexes may lead to aspiration pneumonia; (7) increased activity in various afferent inputs from viscera in the thorax and abdomen; (8) a number of bronchopulmonary clinical disorders. The list is long, but regrettably the nervous mechanisms of these down-regulations have been little studied. In addition there are a number of situations, such as exercise, coitus, talking and singing which, while important to coughing humans, have been not investigated in relation to cough. Most of the studies have been with experimental animals, and their extension to human research is desirable. In view of the importance of cough and other defensive reflexes in maintaining human well-being, far more research is needed. The field is wide-open.
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PMID:Physiological and pathophysiological down-regulation of cough. 1587 97


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