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Biomedical subjects

A Ramírez-Sánchez

Publications and source records attributed to A Ramírez-Sánchez.

5 recordsLinked to original sources
PubMed1995

[Renal function in the immediate postoperative period of abdominal and ophthalmic surgery].

OBJECTIVES: To study changes in kidney function immediately after abdominal or eye surgery and to assess the roles of vasoactive substances: antidiuretic hormone (ADH), renin and aldosterone and natriuretic factors (atrial natriuretic peptide [ANP] and digoxin-like immunoreactive factor [DLIF]) in renal function. PATIENTS AND METHODS: We distributed 23 patients into 2 groups. Group A contained 16 subjects undergoing high abdominal surgery (cholecystectomy) under general anesthesia, and group B included 7 patients undergoing cataract extraction and intraocular lens implantation with peribulbar anesthesia. The first blood sample was taken before anesthetic induction; the first urine sample had been taken 24 hours prior to surgery. The second blood and urine samples were taken 2 hours after the patient's arrival in the intensive care recovery ward. RESULTS: Patients undergoing abdominal surgery experienced significant decreases in diuresis (p < 0.01) and sodium excretion (p < 0.05) and increases of potassium in urine (p < 0.01) and urinary osmolarity, accompanied by high ADN (p < 0.01) and aldosterone (p < 0.01) levels in both blood (p < 0.05) and urine. Renin, ANP and DLIF did not change significantly in patients receiving peribulbar anesthesia. CONCLUSIONS: The increases in ADH and aldosterone levels that occur as a response to stress in abdominal surgery are implicated in the antidiuretic and antinatriuretic effects observed in the postoperative period. Renin, ANP and DLIF do not seem to be responsible for kidney dysfunction.

Adult↗
PubMedDate not supplied

[Pressure changes in the pneumoballoon of several endotracheal tubes after the administration of nitrous oxide].

We compare the degree of nitrous oxide diffusion in three types of endotracheal tubes available in the market, by means of continuous monitoring of the pressure attained at the pneumoballoon. Among the systems designed to impede or to minimize nitrous oxide diffusion, we have used in this study the so called "rediffusion system". When the endotracheal tube possesses this system, the pressure attained at the pneumoballoon remained constant throughout the study period (23.2 +/- 0.53 mmHg at time zero vs 24.2 +/- 0.66 mmHg 50 min after administration of protoxide). In contrast, endotracheal tubes without "rediffusion system" showed a statistically significant increase (p less than 0.05) of pneumoballoon pressure (25.2 +/- 2.43 mmHg and 26.7 +/- 1.01 mmHg at time zero vs 45.2 +/- 3.12 and 44.3 +/- 2.41 mmHg 50 min after protoxide administration in the two other types of endotracheal tubes). We believe that during anesthesia with nitrous oxide the pneumoballoon pressure should be monitored or systems that avoid diffusion of this inhalational agent should be inserted. Our results indicate that endotracheal tubes equiped with "rediffusion system" are effective in impeding diffusion of the inhalational agents.

Adult↗
PubMedDate not supplied

[Propofol and retrobulbar anesthesia for cataract extraction].

We divided 80 patients undergoing cataract surgery into two groups of 40: one control group and one propofol group to whom 1-1.5 mg/kg of propofol was administered before retrobulbar anesthesia. The following parameters were recorded before and after retrobulbar anesthesia: systolic and diastolic arterial pressure (SAP and DAP), heart rate (HR) and finally arterial oxygen saturation through pulse oximetry. Pain was also measured on the Scott-Huskisson visual analog scale. For patients in the control group a rise in arterial pressure over baseline values after 5 minutes (p < 0.01) was observed, while a decrease was found in the propofol group (p < 0.01). The rise after 5 minutes in the control group was significant when compared with the measurements for the propofol group (p < 0.01). The pain measure for the control group reached 5.53 +/- 1.54 on the Scott-Huskisson scale, but was 0 in the propofol group. Measurements on the pain scale correlated positively with diastolic arterial pressure 5 minutes after blockade in the control group (p < 0.05). The technique studied affords greater comfort for the patient, presents no special difficulties for the anesthesiologist performing the retrobulbar blockade, and causes no complications.

Adolescent↗
PubMedDate not supplied

[Particle exposure modeling in the general population and risk of respiratory disease].

Total exposure assessment identifies the various sources of exposure to air pollution which affect each individual, thus functioning as a useful tool in clinical and environmental exposure management. A cross sectional survey was performed in order to create a total exposure model of inhaled particulates. This survey involved 544 subjects located within the Mexico City Merced monitoring station, an area covering three kilometers in diameter. Two questionnaires were developed one on housing and the other on respiratory symptoms. A diary on daily activity was kept, and an outdoor monitoring station was also installed. A new technology was adapted and incorporated for personal and indoor monitoring. A correlation of up to 0.38 was identified between the environmental concentrations. Exposures at home and at other extramural activities are most predictive of personal exposure. It was determined that 8.8% of the subjects studied had chronic bronchitis, and that this percentage increases with greater levels of exposure and outdoor sports. These findings conclude that the models are useful for risk assessment and management in Mexico.

Adolescent↗