Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085383 (hypocapnia)
 1,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. In cats anaesthetized with Saffan, which does not block afferent activation of the brain stem defence areas, we have analysed the cardiovascular changes induced by 3 min periods of graded systemic hypoxia (fraction of O2 in inspirate, Fi,O2, 0.15, 0.12, 0.08, 0.06). 2. At light levels of Saffan anaesthesia, hypoxia (particularly Fi, O2 0.08 and 0.06) or selective stimulation of carotid chemoreceptors evoked the pattern of tachycardia, decrease in renal and mesenteric vascular conductance (RVC, MVC), but increase in femoral vascular conductance (FVC) which is characteristic of the alerting-defence response. This supports our view that activation of the defence areas is an integral part of the response to systemic hypoxia. 3. Hypoxia also induced an increase in frequency of augmented breaths which was graded with the level of hypoxia: 0.6 min-1 at Fi, O2 0.21 to 1.1 min-1 at Fi, O2 0.06; in some cats each of these was accompanied by a transient fall in arterial pressure (ABP) and increase in FVC. It is proposed that these responses were all part of a reflex elicited by lung irritant receptors and facilitated by peripheral chemoreceptors. However, their low rate of occurrence and the liability of the vasodilatation suggests they do not make major contributions to the overall response. 4. The above short-lasting responses were superimposed upon gradual changes whose magnitudes were graded with the level of hypoxia: hyperventilation, slight tachycardia, but bradycardia at Fi, O2 0.6, small increases in ABP, FVC and MVC allowing femoral and mesenteric blood flow to increase, but decreases in RVC which maintained renal blood flow constant. 5. Vagotomy had no significant effect on these changes. Further, hyperinflation of the lungs with pressures of 10 mmHg evoked the Breuer-Hering reflex but had no noticeable cardiovascular effect. It is proposed that, in the cat, reflex tachycardia and vasodilatation elicited by lung stretch receptors play no significant part in the response to hypoxia. 6. By contrast, after pneumothorax, with ventilation and thereby arterial PCO2 (Pa, CO2) maintained constant, graded hypoxia produced graded bradycardia, decrease in MVC and RVC and no change in FVC. Taken together, these results suggest that in the spontaneously breathing cat, the response to hypoxia is dominated by the effects of hypocapnia secondary to hyperventilation, which by inhibiting peripheral and central chemoreceptor activity effectively counteracts the primary bradycardia and peripheral vasoconstriction elicited by hypoxic stimulation of peripheral chemoreceptors. 7. These proposals are compared with those drawn for other species.
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PMID:Analysis of factors that contribute to cardiovascular changes induced in the cat by graded levels of systemic hypoxia. 260 Aug 40

A case is reported of severe interstitial paraquat poisoning in a 23 year old man. Initial treatment consisted of gastric lavage, fuller's earth, haemoperfusion on activated charcoal and peritoneal dialysis. On the third day, appeared both renal and early respiratory failure, with hypocapnia and hypoxia. Peritoneal dialysis was kept up to the thirteenth day. Pulmonary function tests showed a restrictive syndrome. Chemotherapy with 1 mg.kg-1.24 h-1 prednisone and 3 mg.kg-1.24 h-1 cyclophosphamide was started on day 4. Radiotherapy (13 Gy) was also given to both lung fields between days 6 and 10. Despite this treatment, respiratory failure worsened, and the patient died at the 28th day, with resistant severe hypoxaemia and pneumothorax on fibrous lungs. Several reports have shown conflicting results with chemotherapy and radiotherapy in the treatment of pulmonary fibrosis due to paraquat poisoning. The failure of such treatment in the case reported showed the need for large prospective clinical trials of the treatment of paraquat poisoning, as well as for urgent preventive measures.
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PMID:[Failure of chemotherapy and radiotherapy in pulmonary fibrosis caused by paraquat]. 336 14

Respiratory-related activity of the hyopharyngeus (middle pharyngeal constrictor) and thyropharyngeus (inferior pharyngeal constrictor) muscles was determined in decerebrate, tracheotomized adult cats and compared with the electromyographic activity of the thyroarytenoid, a vocal cord adductor. During quiet breathing, the hyopharyngeus and usually the thyroarytenoid exhibited phasic activity during expiration and tonic activity throughout the respiratory cycle. Respiratory-related thyropharyngeus activity was absent under these conditions. Progressive hyperoxic hypercapnia and progressive isocapnic hypoxia increased phasic expiratory activity in both pharyngeal constrictor (PC) muscles but tended to suppress thyroarytenoid activity. Passively induced hypocapnia and the central apnea that followed the cessation of the mechanical hyperventilation were associated with tonic activation of the hyopharyngeus and thyroarytenoid but no recruitment in thyropharyngeus activity. The expiratory phase of a sigh and progressive pneumothorax were associated with an increase in phasic thyroarytenoid activity but no change in phasic PC activity. The results indicate that a variety of stimuli modulate respiratory-related PC activity, suggesting that the PC muscles may have a role in the regulation of upper airway patency during respiration.
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PMID:Respiratory-related pharyngeal constrictor muscle activity in decerebrate cats. 937 24

General anesthesia combined with epidural anesthesia for thoracotomy due to spontaneous pneumothorax was given to a pregnant woman at 21st week of gestation. She was premedicated intravenously with famotidine 20 mg and metoclopramide 10 mg. Mepivacaine 1% was administered through a thoracic epidural catheter. General anesthesia was induced by thiamylal 225 mg, vecuronium 8 mg and fentanyl 100 mcg, and maintained by sevoflurane, vecuronium and fentanyl. Endobronchial intubation with a 35Fr Bronchocath double-lumen tube was successful and one-lung ventilation was commenced to maintain the end-expiratory CO2 pressure at 30 to 35 mmHg with Sp(O2) remaining 100%. Ephedrine 16mg (in 4mg increments) was required to maintain systolic blood pressure above 100 mmHg. After the surgery, ropivacaine 0.2% was administered through the catheter. There were no clinical signs of fetal distress during the perioperative period. Postoperative pregnancy and delivery were uneventful. We succeeded in the anesthetic management by avoiding hypoxia, hypercapnia, hypocapnia and hypotension during the surgery.
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PMID:[Case of general anesthesia combined with epidural anesthesia in a pregnant woman undergoing thoracotomy for spontaneous pneumothorax]. 1827 70