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

Two hundred ninety patients undergoing carotid endarterectomy were reviewed. From 1968 to 1972, 188 patients had carotid endarterectomy under general anesthesia with use of a shunt and hypercarbia. Stump pressures were not recorded in this group. There were three deaths, three postoperative hemiplegias and two complications of transient limb weakness. From 1973 to 1975, 102 patients were operated on under local anesthesia with systemic Innovar and Sublimaze, normocarbia and intra-operative assessment of stump pressure. In this group there was one death, no hemiplegia, and no complications of transient limb weakness. Twenty of the 102 were shunted either on the basis of stump pressure or the loss of motor ability or consciousness on carotid clamping. Those shunted had stump pressures ranging from 10 to 70 mm Hg with a mean of 20 while those not shunted had stump pressures ranging from 20 to 85 mm Hg with a mean of 53 mm Hg. Five patients lapsed into unconsciousness despite internal carotid stump pressures of 30, 30, 34, 36 and 70 mm Hg respectively, thus requiring intraoperative shunting. This experience seriously questions the reliability of carotid stump pressure as the sole determinant to identify those patients who require intraoperative shunting. We have come full circle, back to operation under local anesthesia, since intraoperative assessment of the patient's motor ability and consciousness alone provide the only absolute criteria for assessing the need for intraoperative shunting. Since the operation can be performed with greater technical efficiency without a shunt and without the potential complications of shunting itself, it behooves the surgeon to have a reliable method of knowing when it is not required.
 ...
PMID:Improved results with carotid endarterectomy. 88 76

Peripheral chemoreceptors generally play a limited role in the initial development of diving bradycardia in mammals. However, T.F. Huang and Y.I. Peng (Jpn. J. Physiol. 26: 395-401, 1976) reported that peripheral chemoreceptors are very important for manifestation of the diving response in conscious rats. The objectives of this study were to reinvestigate those findings and determine whether the cardiovascular responses to simulated diving in the rat were potentiated during preexisting hypoxia or hypercapnia. Responses to simulated diving were elicited by nasal water flow with concurrent apnea in paralyzed, artificially ventilated Sprague-Dawley rats anesthetized with Innovar. The experiments show that nasal stimulation in the rat results in rapid bradycardia and hypotension and that these responses are not due to laryngeal stimulation. The data also suggest that chemoreceptors do not play a role in the initiation of the responses to simulated diving in rats and that preexisting chemoreceptor drive does not alter the cardiovascular responses. Additionally, we found that concomitant expiratory apnea is necessary to sustain the profound initial cardiovascular changes induced by nasal water flow.
 ...
PMID:Cardiovascular responses to nasal water flow in rats are unaffected by chemoreceptor drive. 144 22