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Biomedical subjects

G C Carlon

Publications and source records attributed to G C Carlon.

At least 73 records · Page 4Linked to original sources
PubMed1980

Calcium chloride administration in normocalcemic critically ill patients.

Ten normocalcemic critically ill patients who had experienced a decrease in cardiac index greater than or equal to 0.5 liter/min/m2 after incremental changes of PEEP received 7 mg/kg of CaCl2 as a slow iv bolus, followed by an infusion of 20 mg/kg CaCl2 over 60 min. Hemodynamic pressures and flow, oxygen uptake and transport, and blood chemistry variables were determined over a 120-min period. The results indicated that: (1) hemodynamic variables were not affected except for left ventricular stroke work index and mean blood pressure, which increased slightly; (2) both serum calcium and ionized calcium concentrations increased significantly, sometimes to dangerous levels; (3) colloid osmotic pressure and hemoglobin levels decreased slightly but consistently. In conclusion, CaCl2 administration failed to improve hemodynamic function depressed by PEEP. If CaCl2 can play a relevant role in the management of cardiovascular depression, further identification of appropriate doses and patients is necessary.

Aged↗
PubMed1980

Evaluation of an "in vivo" PaO2 and PaCO2 monitor in the management of respiratory failure.

A commercially available gas-chromatograph (Sentorr Gas Analyzer, Ohio Medical Products, Madison, WI) was tested, featuring continuous measurement of in vivo PaO2 and PaCO2 by means of a thin, heparin-coated catheter, inserted through an indwelling arterial line. Gas tensions are displayed every 4 min. The probes had a tendency to break rather easily, and a considerable proportion of them was faulty. We measured 105 paired determinations of blood gases obtained from patients in respiratory failure requiring mechanical ventilation with a Corning IL 175 Analyzer and displayed by the Sentorr Gas Analyzer. A high correlation (p < 0.01) existed between the two sets of values, but an estimated error of 10-20% was found in the Sentorr data. After modifications of the respirator, changes of displayed values were already notable after 4 min and 90% completed by 8-12 min. The use of this device enabled us to considerably accelerate decision-making in the management of respiratory failure. Although techology still necessitates improvements, before widespread use of in vivo monitoring of PaO2 and PaCO2 is advisable, the concept has significant clinical potential and may represent a major advance in the management of respiratory failure.

Carbon Dioxide↗
PubMed1980

Pulmonary venous admixture during mechanical ventilation with varying FIO2 and PEEP.

Many authors have indicated that high FIO2 (0.75-1.0) ventilation may increase pulmonary venous admixture. Reabsorption atelectasis is supposedly responsible for this adverse effect. The authors attempted to determine if increasing PEEP during high FIO2 ventilation could eliminate the detrimental influence of the latter. In 17 patients in respiratory failure, hemodynamic and respiratory variables were measured during ventilation with FIO2 0.50, 0.75, and 1.0 and PEEP varying from -3 to +5 cm H2O from baseline. Before exposure to FIO2 > 0.75, addition of PEEP resulted in a decrease of Qs/Qt from a mean of 26.6-21.9%. After exposure to FIO2 0.75-1.0, Qs/Qt remained at levels not different from baseline, even when PEEP 8 cm H2O above baseline was added. The authors conclude that ventilation with high FIO2 is not useful in determining Qs/Qt, and may prevent the improvement in pulmonary venous admixture associated with PEEP therapy.

Blood Gas Analysis↗
PubMed1980

Prazosin in acute anthracyclene cardiomyopathy.

A 32-year-old woman with a 14-month history of acute lymphoblastic leukemia received 300 mg/sq m of doxorubicin. Shortly after the last course of therapy, congestive failure developed that was attributed to anthracyclene cardiomyopathy. Three weeks later, an acute septic episode was complicated by hypotension and low cardiac output. Adequate blood pressure and cardiac output were restored with a combined intravenous infusion of dopamine hydrochloride and nitroglycerine. Within 24 hours, oral therapy with prazosin and digitalis was initiated, and two days later, the intravenous infusions could be discontinued. Acute anthracyclene cardiomyopathy can be successfully treated with a combination of oral inotropic and vasodilating agents.

Adult↗
PubMed1979

Unexpected giant "V" waves during pulmonary artery catheterization.

Two cases of catheterization of the pulmonary artery, in which the hemodynamic findings were very different from the initial clinical diagnosis, are presented. The importance of verifying the adequate position and motion of the pulomonary artery catheters with two consecutive chest x-rays is discussed. In particular, attention is brought to the possible misinterpretation that occurs in patients with very elevated pulmonary artery mean pressure.

Blood Pressure↗
PubMed1979

Nephrotoxic antibiotics in patients with renal failures: guidelines for debilitated patients.

Fifty-seven cancer patients, who had had an 8--15% loss of body weight in the previous 6 months, were studied to establish the reliabity in wasted individuals of presently available nomograms correlating serum creatinine with creatinine clearance. Other predictors of renal function, such as osmolar clearance, free water clearance, and excreted fraction of filtered sodium, were also considered. In all patients, and especially in those with a measured creatinine clearance 10--50 ml/min, the use of standard nomograms based on serum creatinine resulted in gross overestimation of renal function. None of the other tests of renal function proved reliable for clinical purposes. It is concluded that in wasted patients administration of nephrotoxic drugs that are renally excreted should be adjusted to measured creatine clearance. Using other common predictors of renal function may result in overdosage.

Aminoglycosides↗
PubMed1979

Multiple determination of cardiac output using a two-bottle technique.

A technique is described to perform multiple determinations of cardiac output; two 150 ml bottles of 5% dextrose in water, stored in identical conditions, are immersed in an ice slush, contained in a styrofoam cooler. Comparison of cardiac output determinations obtained with this technique and with multiple syringes indicates very close duplication of results. The technique is very inexpensive and allows one to follow patients for up to four hours with as many as 30 consecutive determinations of cardiac output.

Cardiac Output↗
PubMed1979

Hypoxemia during hemodialysis.

Five mechanically ventilated patients were studied during hemodialysis. The aim was to determine if hypoxemia would develop, and to identify the causes. Respiratory variables (dynamic compliance, peak airway pressure, CO2production); oxygen uptake, and transport variables (alveolar and arterial PO2, pulmonary venous admixture, oxygen consumption); respiratory quotient; pulmonary vascular resistances and white blood cells (WBC) were measured. PaO2 decreased during dialysis, as did PaO2. However, the fall in alveolar oxygen tension failed to explain the hypoxemia. Lung volume did not change significantly, because dynamic compliance, peak airway pressure, and pulmonary vascular resistance were not modified. CO2 losses through the dialysis coil were of little clinical significance. WBC count fell significantly. The authors conclude that ventilation/perfusion and diffusion abnormalities related to leuko-agglutination are responsible for hypoxemia during dialysis.

Carbon Dioxide↗
PubMed1978

Factors influencing postoperative morbidity and mortality in patients treated with bleomycin.

Patients treated with bleomycin are at risk of developing the acute adult respiratory distress syndrome post-operatively. In a prospective study of 12 patients who had received bleomycin preoperatively and were undergoing removal of retroperitoneal lymph nodes or pulmonary metastases several preventive factors were established. These were the use of low concentrations of inspired oxygen during operation and in the immediate postoperative period, careful monitoring of fluid replacement, and restriction of crystalloids in favour of colloids.

Adolescent↗
PubMed1978

Adverse effects of calcium administration. Report of two cases.

Calcium chloride, 7 mg/kg, and calcium gluconate, 20 mg/kg, were administered to patients with low or low-normal levels of serum ionized calcium. Both patients had low blood pressure and cardiac index, and did not respond to digitalis, volume expansion, and beta-adrenergic stimulation with dopamine. Administration of calcium rapid increase of serum ionized calcium levels, decrease of serum potassium levels, and development of severe cardiac arrhythmias. Atrioventricular dissociation and further fall of cardiac index and blood pressure were common features of both cases. Administration of exogenous calcium can cause severe complications, even when theoretically indicated.

Adult↗
PubMed1978

Criteria for selective positive end-expiratory pressure and independent synchronized ventilation of each lung.

Respiratory failure of different origins often requires therapy with mechanical ventilation and positive end-expiratory pressure (PEEP). These supports are occasionally inadequate if the damage to one lung is significantly more pronounced than that to the other lung. Technical means exist to ventilate each lung independently or to provide a different PEEP to each lung. The findings from nine patients in whom one of these techniques was applied are presented, and advantages and disadvantages are discussed.

Adult↗