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Biomedical subjects

S Ramanathan

Publications and source records attributed to S Ramanathan.

At least 127 records · Page 7Linked to original sources
PubMed1980

Tracheobronchial cytologic changes during prolonged cannulation.

The tracheobronchial cytology of eighteen patients undergoing prolonged mechanical ventilation were examined for the type of cell population present, together with the morphologic integrity of the ciliated epithelial cells 1, 3, 5,10, and 20 days after tracheal cannulation. Smears obtained from patients recovering from cardiac surgery were different from all others in that: (1) they contained fewer epithelial cells (ciliated and squamous) which disappeared earlier; (2) they initially had more pus cells which appeared earlier; (3) they originally contained more histocytes but these were not found after the 5th day after cannulation; and (4) their ciliated epithelial cells displayed more cytomorphologic changes. Differences in cytology were attributed to impaired cardiac output in these patients. The reduced perfusion pressure of the vasculature of their tracheobronchial tree was presumably unable to sustain the lateral wall pressure of tube cuffs pressure, which further impaired tracheal perfusion. Less reparative processes (squamous metaplasia and early appearance of histiocytes) were also found in patients following cardiac surgery, together with early invasion of smears by pus cells indicating premature lowered resistance to bacterial infection.

Adolescent↗
PubMed1979

Humidity and the anesthetized patient.

Damage to the ciliated cells of the tracheobronchial tree and incidence of postoperative pulmonary complications were measured by point-scoring systems in 202 patients who breathed dry and humidified anesthetic gases for 225 +/- 78 min. The incidence of postoperative pulmonary complications decreased as the humidity of administered anesthetic gases increased from 0 to 32.5 mg H2O/l. A similar relationship was found between the amount of inhaled moisture and the damage to the ciliated epithelium of the tracheobronchial tree. These results appear to indicate that a high inspired humidity is beneficial for operations on normothermic patients, and that cellular damage caused by dryness is a possible contributory factor in the production of the pulmonary atelectasis that follows stoppage of the mucociliary transport system in the immmediate postoperative period.

Adolescent↗
PubMed1979

An improved program to calculate intrapulmonary shunting.

A computer program was developed to calculate intrapulmonary venous admixture on a Texas Instruments TI 59 programmable calculator. The program incorporates the following characteristics: 1) a correction for saturated water vapor pressure which varies with body temperature; 2) a mathematical model of the standard oxyhemoglobin dissociation curve; and 3) correction factors for shifts of the dissociation curve due to variations in pH and carbon dioxide tension. It also corrects oxygen tensions obtained at electrode temperature to those at patient temperature, and calculates variations of the Bunsen solubility coefficient of oxygen in blood with body temperature.

Bionics↗
PubMed1978

A high-humidity circle system for infants and children.

A scaled-down version of a modified adult circle system capable of increasing normal humidity output 300% was constructed for pediatric use. The moisture content of the gases leaving the system was tested and found to be superior to that of any pediatric circle system commercially available that does not incorporate an electrically heated water vaporizer.

Anesthesia↗
PubMed1978

Tracheobronchial cytologic changes in malignant melanoma.

Histiocytes counted in smears made from the tracheobronchial washings of 208 patients with malignant melanomas were found to be 3.12 times more numerous than in a control group comparable in sex, age (decades), and smoking habit but without any type of prediagnosed malignant lesion. The discovery of this phenomenon may lead to the development of a new method for the evaluation of therapeutic methods in patients with melanotic lesions. It may open novel pathways for the investigation of cell-mediated immunity in patients with certain forms of malignant disease.

Adolescent↗
PubMed1975

Determining patency of palmar arches by retrograde radial pulsation.

The patency of palmar arches must be ascertained before radial-artery cannulation is performed. A simple test in which digital pulsation is felt after proximal occlusion of the radial artery has been devised for that purpose. The method is reliable, does not require active patient cooperation, and can be carried out in all clinical situations where the radial artery can be felt.

Arteries↗
PubMed1975

Cytology of respiratory epithelium as a predictor of respiratory complications after operation.

A study of 111 patients undergoing elective surgery under general endotracheal anesthesia has shown that the pulmonary complication rate after operation is minimal in nonsmokers (7.9 percent) and that it rises steadily as smoking habit increases, reaching 43 percent in very heavy smokers. Peak expiratory flow rate and timed vital capacity (FEV1) were unaffected before operation except in very heavy smokers. The morphologic integrity of the ciliated tracheobronchial epithelial cells seen in smears obtained within ten minutes of the onset of anesthesia and quantitated by a scoring system, deteriorates progressively with increasing smoking habit and constitutes the most sensitive index for the prediction of diminished resistance to the stress of anesthesia and operation and of incipient chronic obstructive lung disease in smokers.

Bronchi↗
PubMed1974

Tracheobronchial epithelial multinucleation in malignant disease.

Multinucleated tracheobronchial ciliated epithelial cells seen in smears from 112 patients suffering from a wide variety of malignant tumors were found to be 2.08 times more numerous than in a control group comparable in sex, age (decades), and smoking habit but without prediagnosed malignancies. The recognition of this phenomenon may lead to the development of a new test for the diagnosis of occult cancer and may open new pathways for investigation of cancer-host relationships.

Adolescent↗