Biomedical subjects
V K Puri
Publications and source records attributed to V K Puri.
Platelet serotonergic mechanisms in ischaemic heart disease.
The uptake, basal content and efflux of serotonin (5-HT) from the platelets of patients of ischaemic heart disease (I.H.D.) was studied and compared with normal platelets. A significant increase in uptake and basal content of 5-HT as well as increase in 5-HT efflux was observed as compared to control. Our data indicate that I.H.D. is associated with platelet serotonergic dysfunction which seems to indicate that the platelets are preactivated in I.H.D.
Intravenous streptokinase in the management of a subset of patients with unstable angina: a randomized controlled trial.
We report the results of a randomized controlled trial of intravenous streptokinase in a subset of patients with unstable angina. Seventy-six patients were admitted with prolonged (more than 20 minutes) angina at rest of less than 3 weeks onset. Fifty-two patients continued to have more than 3 episodes of prolonged angina in 48 hours on medical therapy with metoprolol, isosorbide dinitrate, nifedipine and intravenous nitroglycerin. Forty-eight patients consented to enter the study and were randomized into two groups. The first group, of 24 patients, received 1.5 million units of streptokinase infusion and the second group, also of 24 patients, received a placebo. Pain relief within 48 hours was achieved in 19/24 (79.1%) patients after streptokinase infusion as compared to 9/24 (37.5%) of the controls (P less than 0.05). Approximately 90% (17/19) of patients responding to streptokinase therapy were relieved of chest pain within the first six hours as against none in the controls. The incidence of acute myocardial infarction within six months was 12.5% (3/24) in those receiving streptokinase and 25% (6/24) in the controls. Mortality at six months stood at 8.33% (2/24) in the treated patients and 16.6% (4/24) in the controls. Intravenous streptokinase thus appears to be of benefit in patients with angina at rest of recent onset which does not respond to conventional medical therapy.
Unusual "high take off" of the right coronary artery from the ascending aorta.
An exceedingly rare anomaly is described in which the right coronary artery originated two centimetres above the left posterior sinus of Valsalva in association with an aortic valve having two leaflets.
Colloid versus crystalloid war--a time for truce.
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Critical Care Scoring System--new concept based on hemodynamic data.
Based on the rationale that hemodynamic, oxygen transport, and perfusion derangements describe physiologically important abnormalities in critically ill patients, we devised a Critical Care Scoring System (CCSS). The database includes a retrospective analysis of 318 patients managed with pulmonary artery catheters during 1986 to 1988. For comparison, Acute Physiology and Chronic Health Evaluation (APACHE II) score was computed for these patients. CCSS includes a total of 17 variables with a weighted score of 71. The mortality rates for increases by 5 points were observed and were statistically significant (p less than .0001). The same was not true for APACHE II. Although neither of the scores could predict ICU days, both reflected the number of life-threatening complications. Serial CCSS that was computed at 24 +/- 4 h (CCSS-C) provided documentation for improvement in patient condition secondary to therapeutic interventions. Statistically improved mortality prediction was observed with CCSS-C. Since 70 (45.7%) of 153 patients died with an APACHE II score less than 14, it appears that this score is deficient in a specific group of patients, i.e., those requiring invasive monitoring. For patients with circulatory or respiratory failure, CCSS may offer a better tool to predict mortality and evaluate therapy.
Lactate levels as predictors of the relationship between oxygen delivery and consumption in ARDS.
We reviewed the changes in Do2 and Vo2 in 58 patients with ARDS after interventions which included fluid loading, blood transfusion, and PEEP. After a significant change in Do2, patients with lactic acidosis (lactate level greater than 2.4 mmol/L) exhibited significant corresponding changes in Vo2 (p less than 0.001); however, no change in Vo2 was observed in patients without lactic acidosis (1-beta greater than 0.8). We conclude that a biphasic pattern of oxygen utilization in patients with ARDS emerges when subsets of patients with and without lactic acidosis are compared. Lactic acidosis, a marker of anaerobic metabolism, may be a characteristic of patients with ARDS who exhibit changes in Vo2 that are dependent on changes in Do2.
Failure of oral atenolol and verapamil to increase the capacity and duration of exercise in patients in sinus rhythm with mitral stenosis.
The efficacy of oral atenolol in increasing the capacity and duration of exercise in 43 patients in sinus rhythm with mitral stenosis was evaluated and compared with that of oral verapamil in an open-label cross-over design. It was observed that although oral atenolol (100 mg per day) caused significant reductions in heart rate while resting and during exercise (P less than 0.001), the increases in capacity and duration of exercise were not significant. Oral verapamil (80 mg three times per day) also caused significant reductions in the heart rates at rest and during exercise (P less than 0.05) but the increases observed, although greater than that with atenolol, failed to reach the level of statistical significance. Occasional side effects occurred with both the drugs. Subjective symptoms of dyspnoea at rest and on exertion were relieved with both the drugs. We conclude that, although both drugs reduce the symptoms of dyspnoea, they cause only minor increases in the objective parameters. They do not, therefore, provide an alternative to surgery and have only a temporary place in the management of patients in sinus rhythm with mitral stenosis who are awaiting surgery.
Continuous monitoring of mixed venous oxygen saturation in patients with acute myocardial infarction.
Continuous measurement of mixed venous oxygen saturation (SvO2) has been suggested as an adjunct in monitoring critically ill patients. We evaluated SvO2 monitoring in 24 patients suffering from complicated myocardial infarctions. Cardiac output and arterial lactate levels were measured when there were persistent 5 percent changes in SvO2, and otherwise, every 12 hours or as indicated clinically. Increases in SvO2 by 5 and 10 percent corresponded with an increase in cardiac index in 78.5 percent and 75 percent of measurements, respectively. Decreases in SvO2 by 5 and 10 percent corresponded with decreases in cardiac index in 45.5 percent and 61 percent of measurements. Twenty percent changes in cardiac index showed dissimilar directional changes with SvO2 in 62 percent of cases. Arterial blood lactate levels correlated poorly with SvO2. Survivors had significantly higher mean SvO2 and cardiac indices than nonsurvivors (p less than 0.01). The clinical management of patients with myocardial infarction may not be altered in view of the limitations of SvO2 in reflecting tissue hypoxia. We conclude that continuous monitoring of SvO2 may not be a sensitive measure of cardiac output after acute myocardial infarction.
Cardiac output changes and continuous mixed venous oxygen saturation measurement in the critically ill.
For many years, the pulmonary artery catheter has been used to monitor cardiac filling pressures and to determine cardiac output in hemodynamically unstable patients. Recently, a new pulmonary artery catheter with fiberoptic capabilities, which provides continuous mixed venous O2 saturation (SvO2) measurements, has become available and has been found to be helpful in managing unstable patients. To determine the efficacy of this device in predicting early changes in cardiac output, we studied 46 patients catheterized with the opticath and 25 with the standard pulmonary artery catheter; we compared changes in the SvO2 with associated cardiac index changes. We found that small changes (5%) in SvO2 did not correlate well with changes in cardiac output, yet larger changes (10%) in SvO2 seemed to correlate better. More importantly, we found that only 50% of the SvO2 changes predicted anticipated changes in cardiac output. As can best be determined from the limitations of a nonrandomized study, the value of continuous SvO2 monitoring as an early predictor of cardiac output change remains questionable.
Extravascular lung water measurement by double indicator dilution in shock and respiratory failure.
Clinical quantitation of water accumulation in the lungs is imprecise. The technique of measuring extravascular lung water (EVLW) with double indicator dilution utilizing cold indocyanine green dye has become practical with the addition of a microprocessor. The technique, insertion of a special thermistor tipped arterial catheter and potential problems are described. Our studies with resuscitation of 27 patients in shock indicate little increase in EVLW at 24 hours. On the other hand 19 patients with Adult Respiratory Distress Syndrome (ARDS) had marked increases in EVLW from normal of 5-8 ml/kg to 10.7 to 14.4 ml/kg. No further increases in EVLW were observed in eight ARDS patients requiring fluid resuscitation for associated hypovolemia and hypoperfusion. We feel that measurement of EVLW in critically ill patients offers an opportunity to study the pathophysiology of pulmonary failure.
Value of the treadmill exercise test in asymptomatic and minimally symptomatic patients with chronic severe aortic regurgitation.
The value of the graded treadmill exercise test was assessed in 19 asymptomatic and minimally symptomatic (13 NYHA class I and 6 NYHA class II) male patients with chronic severe aortic regurgitation. It was observed that, in 2 patients who showed significant ST segment depression at peak exercise, the total exercise duration was significantly shorter (P less than 0.001) than in the patients not showing such changes. During left ventricular and aortic root angiography (in both patients) and selective left coronary angiography (in one of them), ST segment changes similar to those seen during exercise testing were observed. The mean rise in left ventricular end-diastolic pressure after injection of contrast material was significantly more (P less than 0.001) in these 2 patients compared to the other 17 patients. Both patients had normal resting M-mode echocardiographic parameters. It is concluded that ST segment depression on exercise testing and reduced exercise capacity are indicants of exercise-induced left ventricular dysfunction in asymptomatic and minimally symptomatic patients with chronic severe aortic regurgitation. Furthermore, it is suggested that this simple and cheap test can be used for serial evaluation of such patients in the absence of the facility of radionuclide cineangiography.
Cardiopulmonary resuscitation in hospitalized patients: continuing problems of decision-making.
Disturbingly low survival rates after CPR prompted us to carry out a series of studies. Of 272 patients receiving CPR at our 600-bed community hospital in 1984, 102 (37.5%) patients survived initial resuscitation and 30 (11%) survived their hospitalization. Of the 102 initial survivors, only 15 patients had received full CPR including cardiac compression and/or defibrillation, endotracheal intubation, and cardiotonic drugs. These data were compared with those for 129 patients admitted to our critical care units in 1982 and 1983 in whom CPR was withheld. These patients had been designated "No CPR" primarily because of their poor response to therapy. There was an 11% survival rate for patients who had received CPR compared to a 16% survival rate for the "No CPR" group. These data suggest that criteria for administering CPR to hospitalized patients should be improved.
Pulmonary edema in renal transplant patients.
A syndrome heralded by fever, deterioration of graft function, respiratory failure accompanied by pulmonary infiltrates has been termed "transplant lung." We hemodynamically studied eight such patients. At the height of their illness, pulmonary artery wedge pressure (PAWP) was elevated to 19.3 +/- 2.6 mm Hg along with mean pulmonary artery pressure (PAP) of 35.0 +/- 3.8 mm Hg in presence of increased cardiac index (CI) of 4.9 +/- 0.9 L.m2.min. Pathophysiology of pulmonary edema appears to include high left ventricular filling pressures, pulmonary hypertension, alterations of oncotic hydrostatic gradient, and increased cardiac output. A partial reversal of pulmonary hypertension was observed with dialysis or diuresis. Our data suggest incipient renal failure and fluid accumulation as the etiology of hemodynamic pulmonary edema in "transplant lung."
Sulphinpyrazone and the platelet serotoninergic mechanism in ischaemic heart disease.
A double blind study in 25 patients with ischaemic heart disease and 20 matched healthy controls examined the effect of sulphinpyrazone on the uptake of serotonin by platelets and the basal concentrations of serotonin in platelets. Uptake was measured using tritium labelled serotonin and basal concentrations estimated spectrophotofluorometrically. Serotonin uptake was significantly increased both in the patients with chronic stable angina of effort and in those with a history of myocardial infarction six months or more previously. Sulphinpyrazone reduced serotonin uptake from 94.25 (SE 8.65) to 57.86 (5.37) cpm/10(8) platelets after 24 weeks of treatment in the group with stable angina and from 137.45 (16.26) to 68.08 (8.38) cpm/10(8) platelets in the myocardial infarction group. Raised basal concentrations in the two groups were also reduced by sulphinpyrazone. Placebo had no effect on serotonin uptake or basal concentrations in either group of patients. The ability of sulphinpyrazone to inhibit uptake and reduce basal concentrations of serotonin in patients with ischaemic heart disease may be yet another mechanism through which this drug exerts its beneficial antiplatelet effect.
Pulmonary artery catheterization--uses and abuses.
Pulmonary artery (PA) catheterization has been extensively employed in the care of the critically ill and injured patients. As the clinical experience has increased, so has the list of indications and complications. Doubts have arisen as to the appropriateness of PA catheterization and positive contributions to patients care. Consensus can be reached as to the usefulness of PA catheterization in patients with severe shock syndromes, adult respiratory distress syndrome and refractory cardiac failure. Patients who require large doses of vasoactive agents may benefit from assessment of hemodynamics. Patients with minimal disease or easily correctable hypovolemia can be safely managed without PA catheter. Similarly patients with chronic obstructive pulmonary disease and renal failure requiring dialysis rarely need PA catheterization. Since technical, septic and thromboembolic complications can develop in a significant number of patients, cost benefit oriented analysis in various subsets of patients is needed. Diagnostic information derived from PA catheters should be related to the clinical condition and shortcomings and pitfalls of data clearly understood. Various indications and their relevance to patient care is reviewed.
Detection of right atrial mass by echocardiography in pulmonary thromboembolism.
An echodense mass in the right atrium was detected incidentally by two-dimensional echocardiography (ECHO) in a patient with clinical suggestions of cardiogenic shock. Autopsy revealed a cylindrical thrombus extending from the right atrium through a patent foramen ovale, and bilateral massive pulmonary thromboembolism (PTE). Pulmonary thromboembolism should be one of the differential diagnoses in patients with an echodense mass in the right heart.
Oxygen delivery and consumption and P50 in patients with acute myocardial infarction.
We investigated the relationship between oxygen delivery (DO2), oxygen consumption (VO2), and influence of oxyhemoglobin dissociation (P50) on VO2 in 40 patients with complicated myocardial infarction. A decrease in VO2 and an increase in P50 were observed as DO2 decreased due to pump failure. In a given range of DO2, VO2 was related to P50 in survivors (r values .472 to .647, p less than .01). Each millimeter of mercury increase in P50 was associated with a 5.2 to 6.5 ml/min X m2 increase in VO2 when DO2 was less than 450 ml/min X m2. No similar correlation was found for nonsurvivors. Lactate was higher in nonsurvivors despite the fact that DO2 and VO2 were similar in the two groups. The lack of compensatory increases in P50 may be pathologic in nonsurvivors. However, the value of VO2 as an indicator of tissue oxygenation or survival in patients with acute myocardial infarction is questionable.