PubMed Health⌕ Search

Biomedical subjects

S Podolsky

Publications and source records attributed to S Podolsky.

At least 19 recordsLinked to original sources
PubMed1989

The relationship of conjunctival and arterial blood gas oxygen measurements.

Conjunctival oxymetry (CjO2) measures peripheral tissue oxygen at the conjunctival level. CjO2 changes can indicate pulmonary or circulatory conditions leading to shock. Literature review does not define 'normal' CjO2/ABG PaO2 ratios. We designed a study to measure these ratios. Twenty-two healthy patients undergoing cardiac catheterization had simultaneous PcjO2 and PaO2 measurements completed. The range of conjunctival oxygen measurements was from 34 to 68 mmHg with a mean of 50.5 mmHg. The PaO2 readings ranged from 65 to 93 mmHg with a mean of 77.1 mmHg. The average PcjO2/PaO2 ratio was 0.656 with a range of 0.47-0.93. Thus the PcjO2 is on average 66% of the arterial blood gas PaO2. This ratio of 0.66 can serve as a base for further clinical studies in which PcjO2 is looked at in patients with pulmonary or circulatory illnesses or injuries.

Adult↗
PubMed1987

Renin suppression by saline is blunted in nonmodulating essential hypertension.

We have reported that 50% of subjects with normal renin essential hypertension have both delayed suppression of the renin-angiotensin-aldosterone axis following sodium infusion and a delayed rate of excretion of an acute salt load. In another study we have also described a subset of patients with essential hypertension (called nonmodulators) who have several abnormalities, including a pressor response to salt loading. To evaluate whether the abnormalities described in these different groups of patients actually occur in the same patient, we assessed the renin-angiotensin-aldosterone axis response to short-term saline loading in 38 hypertensive patients. Their ability to modulate was determined by their renal vascular response to infused angiotensin II on a high salt diet (200 mEq Na). In response to a 3-hour infusion of saline, 75 mEq/hr, the reduction in plasma renin activity at both 60 and 120 minutes was significantly greater (p less than 0.008) in patients with normal modulation than in the nonmodulators. Plasma aldosterone levels were also significantly lower (p less than 0.001) in those with intact modulation. Thus, nonmodulating essential hypertensive patients have abnormalities in several systems that influence sodium homeostasis, including altered adrenal and renal vascular response to angiotensin II, altered renal blood flow response to salt loading, and a delayed suppression of the renin-angiotensin-aldosterone system with short-term saline infusion.

Adult↗
PubMed1983

A review of research methodology in an emergency medicine journal.

All original articles published in JACEP and Annals of Emergency Medicine in 1972, 1975, 1978, and 1981 were reviewed and classified according to type of article, research design, specific methods utilized, and statistical analyses employed. The number of articles published annually increased during the 10-year period, from 34 in 1972 to 131 in 1981. The percentage of articles devoted to clinical research, basic science, animal studies, and health services research also increased: 1972, 8.8%; 1975, 39.6%; 1978, 41.2%; and 1981, 51.1%. In 1972, only two studies had defined research designs. In 1981, 47 studies had the following research designs: case control, 9; cohort, 9; cross-sectional, 13; uncontrolled clinical trial, 3; non-random clinical trial, 7; and randomized clinical trial, 6. Research methodologies were defined in only two studies published in 1972, but increased in each of the years reviewed to 41 in 1978. The most common methodology was the use of diagnostic categories. In 1972, statistical analysis was limited to descriptive enumeration and was included in only three articles. In 1981, 62 articles contained statistical analyses, including chi square in 11; t test in 6; Fischer's exact test in 2; ANOVA in 4; and P value (method not stated) in 10. This study reveals a major increase in both the quality and quantity of emergency medicine research published during the 10-year period reviewed.

Emergency Medicine↗
PubMed1983

Central venous catheterization in the emergency setting.

To determine the appropriateness and rate of complications from central venous catheterization (CVC) in the emergency department of a university teaching hospital, criteria for justifiability were established and all such catheterizations during a 1-yr period were reviewed. Of 61 catheterizations in 57 patients, 41% could not be justified according to the criteria established. Eight (14%) patients had serious complications from catheter placement. This complication rate is higher than that in any previously published study, but no other study has examined only emergent catheter placement. These findings underline the importance of adhering to a limited set of indications for CVC in emergency departments.

Catheterization↗
PubMed1983

Efficacy of cervical spine immobilization methods.

Cervical spine immobilization devices are widely used to stabilize the cervical spine and prevent neurologic deficits associated with unstable fractures. In order to quantitate their efficacy we measured controlled cervical spine motion in three axes, using six different immobilization methods in 25 volunteers instructed to actively move their necks as much as possible in the directions of flexion, extension, rotation, and lateral bending while lying supine. Control measurements were made with no device and measurements were repeated following immobilization with: soft collar (SC), hard collar (HC), extrication collar (EC), Philadelphia collar (PC), bilateral sandbags joined with 3-inch cloth tape across the forehead (ST), and the combination of sandbags, tape, and the Philadelphia collar (ST/PC). Neck movements were reported in degrees recorded on a hand-held goniometer. There were no significant differences between control and SC measurements except in rotary movement. PC was not significantly better than the other two types of hard collars, except in limiting extension. ST immobilization was significantly better than any of the other four methods used alone, for all four movements. The addition of PC to ST was significantly more effective in reducing extension only.

Adolescent↗
PubMed1983

Defect in the sodium-modulated tissue responsiveness to angiotensin II in essential hypertension.

In normal subjects, dietary sodium intake modulates renovascular, adrenal, and pressor responses to infused angiotensin II (AII). To examine the hypothesis that this modulation is abnormal in some patients with essential hypertension, we studied 18 hypertensives and 9 normal subjects twice--during dietary sodium restriction and during loading. Paraaminohippurate (PAH) clearance was used to assess renal plasma flow. AII was infused in graded doses (0.3-3.0 ng/kg per min). Plasma aldosterone, cortisol, renin activity, AII, sodium, potassium, and PAH clearance were measured at the onset and end of each AII dose. During dietary sodium repletion, eight of the subjects with essential hypertension showed a normal renovascular response (greater than 125 ml/min per 1.73 m2) to AII infusion (3 ng/kg per min). The decrement in renal blood flow in these normal responders (NR) was 168 +/- 10, which was comparable to the range in normotensive subjects (206 +/- 25 ml/min per 1.73 m2). All of the remaining hypertensive patients, designated abnormal responders (AbR), had lower (less than 125) renal blood flow responses to the same dose of infused AII (mean decrement: 84 +/- 11 ml/min per 1.73 m2) compared with the NR and normotensive subjects. Renal blood flow responses to all AII doses were statistically greater on a high-vs.-low salt diet in the NR (P less than 0.001, chi-square) and normotensives (P = 0.004, chi-square) but sodium intake had no effect on this response in the AbR. Basal renal blood flow in NR increased significantly (P less than 0.001, paired t test) with dietary sodium repletion, from 491 +/- 36 (low salt) to 602 +/- 40 ml/min per 1.73 m2 (high salt), but was almost identical in the AbR on differing dietary sodium intakes (429 +/- 24 vs. 425 +/- 26 ml/min per 1.73 m2). The adrenal responses to sodium intake and infused AII also differed in the two subgroups. In the NR, the adrenal response to AII was significantly greater (P = 0.011, Wilcoxon signed rank test) after sodium restriction. In contrast, there was no significant difference in the aldosterone response to AII infusion between the low and high sodium diets in the AbR. Thus, a substantial subgroup of essential hypertensives has an abnormality in responsiveness to AII in two systems central to volume homeostasis: the kidney and adrenal. They fail to modulate their renal blood flow and aldosterone responses to AII with changes in dietary sodium intake. Moreover, basal renal blood flow does not increase appropriately with increased sodium intake. These abnormalities, which may be due to an increased local production of AII or a defect in the AII receptors in these three target tissues, could contribute to the elevated blood pressure.

Adolescent↗
PubMed1982

Transcutaneous oxymetry measurements during acute blood loss.

Transcutaneous PO2 (TcPO2) was measured in healthy adult blood donors to test the sensitivity of this method as a noninvasive means of diagnosing occult blood loss. TcPO2, the energy required to heat the electrode (MW), and postural changes in blood pressure and pulse, were measured before and after a 450-ml blood donation. There was a significant increase (P less than .005) in postural pulse of 4.8/min, but no significant change (P greater than .05) in postural blood pressure. There was no significant change (P greater than .05) in TcPO2, but there was a significant decrease (P less than .001) in MW. These MW changes probably reflect physiologic changes associated with blood loss.

Blood Pressure↗
PubMed1981

Alterations in aldosterone biosynthesis in essential hypertensives.

We studied hypertensives with decreased adrenal responsiveness to infused angiotensin II (AII) to assess their responsiveness to other aldosterone secretagogues, ACTH and potassium, which are thought to stimulate aldosterone synthesis in sites different from one another and from AII. All subjects, following sodium restriction, received an infusion of AII in increasing doses (0.1-3 ng/kg per min). The increment in aldosterone between control and the highest infusion dose divided by the increment in plasma AII was used as the index of adrenal responsiveness. All normotensive controls (NC) had a ratio greater than 0.5. Hypertensives with a normal ratio were designated normal responders (NR) and those with a lower ratio were abnormal responders (AbR). The slope of the regression line between aldosterone and AII was significantly less for the AbR (0.02 +/- 0.04) than for the NR (1.20 +/- 0.02, P less than 0.001) and the NC (1.00 +/- 0.03, P less than 0.001) groups. During infusion of cosyntropin in increasing doses (0.05-1.5 mIU/kg per 30 min), the aldosterone response of the AbR was significantly less than that of the NR (P less than 0.016) or the NC (P less than 0.05) groups. Similarly, after infusion of potassium (0.33 mEq/min), the increment in aldosterone in the AbR group (7.6 +/- 2.2 ng/dl) was significantly less than that in the NR (14.2 +/- 2.5 ng/dl, P less than 0.05) and the NC (18 +/- 5 ng/dl, P less than 0.05) groups. Thus hypertensives with decreased aldosterone responsiveness to infused AII also had decreased responsiveness to infused ACTH and potassium, suggesting that their defect lies in the intracellular aldosterone biosynthetic pathway.

Adrenocorticotropic Hormone↗
PubMed1980

Diabetic retinopathy: update on therapeutic advances.

It is clear that real advances have occurred in the therapy of diabetic retinopathy. However, this complication of diabetes can and does lead to blindness in the older patient. The present treatment modalities offer a means of maintaining or, in some patients, improving the visual performance of the patient. Laser photocoagulation and vitrectomy are the major new therapies. The future will hopefully give us a better understanding of the cause of diabetic retinopathy so that it may be prevented and cured. However, in the interim, all patients with diabetes mellitus should be urged to see on ophthalmologist yearly in order to obtain the best available therapy.

Adult↗