Brazilian journal of medical and biological research = Revista brasileira de pesquisas médicas e biológicas
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Braz. J. Med. Biol. Res. · Jan 1989
Cerebral blood flow following hypertonic saline resuscitation in an experimental model of hemorrhagic shock and head injury.
Hypertonic (3.0%) saline (HS) resuscitation from hemorrhagic shock is associated with less cerebral edema and lower intracranial pressure (ICP) compared to normal saline (NS) and 10% Dextran 40 (D-40). The effect of HS resuscitation on cerebral blood flow (CBF) is unknown. Beagle dogs with a head injury underwent shock and resuscitation, receiving either NS (N = 6), HS (N = 6), or D-40 (N = 6). ⋯ Global and hemispheric CBF values were not different between groups at times measured. ICP was significantly lower in animals receiving HS. Therefore, lower ICP following HS resuscitation is not associated with alteration in CBF.
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Braz. J. Med. Biol. Res. · Jan 1986
Respiratory and acid-base parameters during salicylic intoxication in dogs.
This paper examines the mechanism responsible for hyperventilation and accompanying respiratory alkalosis during acute salicylism. Sodium salicylate (250 mg/kg) was administered to 8 spontaneously breathing anesthetized dogs (alpha-chloralose, 50 mg/kg, and urethane, 500 mg/kg, iv). The trachea was sectioned and connected to a pneumotachograph. ⋯ Only a small part of hyperventilation can be attributed to the temperature increase. A high correlation coefficient (r = 0.974) was obtained by regression analysis of the values for ventilation and CSF salicylate. We conclude that the central action of salicylate is much more important for increasing ventilation than effects related to oxidative phosphorylation uncoupling.
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Braz. J. Med. Biol. Res. · Jan 1985
The Bezold-Jarisch-like effect induced by veratridine and its potentiation by scropion toxin in the rat.
The Bezold-Jarisch-like effect (BJE) induced by 2.5 micrograms/100 g of veratridine injected intravenously or into the left ventricle was studied in anesthetized rats. The possible potentiation of the effect by a small dose (10 micrograms/100 g) of a purified scorpion toxin (tityustoxin) was also investigated. Heart rate (HR), electrocardiogram (ECG), mean arterial pressure (MAP) and respiratory rate (RR) were recorded. ⋯ The ECG showed that hypotension induced by iv or lv injections of veratridine coincided with a slight sinus bradycardia before tityustoxin (N = 9) and A-V block after the toxin (N = 18). Cervical bilateral vagotomy prevented the cardiac and respiratory effects induced by lv veratridine in tityustoxin-treated rats, but a slight hypotension was still recorded (from 114 +/- 10 to 94 +/- 10 mmHg, P less than 0.05). Injection of veratridine (2.5 micrograms/100 g) into the ascendent aorta evoked a slight hypotension (from 105 +/- 6 to 87 +/- 7 mmHg, P less than 0.05) and tachypnea followed by bradypnea, but bradycardia was not recorded.(ABSTRACT TRUNCATED AT 400 WORDS)
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Braz. J. Med. Biol. Res. · Jul 1983
Relationship between mouth and esophageal pressures in different body postures.
Static voluntary efforts, both inspiratory and expiratory (executed with the glottis open against a closed airway) are commonly utilized for the evaluation of correct esophageal balloon positioning for indirect pleural pressure measurement. Agreement between delta Pm (change in mouth pressure) and delta Pes (change in esophageal pressure) indicates the valid indirect determination of pleural pressure. Measurements of delta Pes are more commonly made with the thorax in the upright position, and some investigators have reservations about determinations carried out in the supine position. ⋯ Phase differences between delta Pes and delta Pm were very small in different body positions. Cardiac artifacts in esophageal measurements were more pronounced in the horizontal and -10 degrees positions. The "occlusion test" is particularly useful for clinical application because it does not require patient cooperation and is a very simple technique for evaluating correct esophageal catheter placement.