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S M Poler

Publications and source records attributed to S M Poler.

7 recordsLinked to original sources
PubMed1991

Noninvasive detection of the morphologic and hemodynamic changes during normal pregnancy.

To characterize the morphologic and hemodynamic changes during normal pregnancy, serial echocardiographic measurements (n = 210) of left ventricular (LV) dimensions and mass (M-mode), volumes and ejection fraction (two-dimensional), stroke volume, and cardiac output (Doppler: aortic, apical, and suprasternal) were performed in 15 patients (mean age 30 years) beginning as early as 12 weeks of gestation, at 2-week intervals through delivery, and up to 12 weeks postpartum. Left atrial size increased from 3.4 +/- 0.4 (SD) to 3.8 +/- 0.4 cm near term, decreasing to 3.4 +/- 0.5 cm postpartum (p = 0.006 overall). LV mass changes correlated with increases in body weight. No consistent significant changes in LV volumes and ejection fraction were observed. LV outflow tract cross-sectional area increased significantly from 3.0 +/- 0.2 cm2 at baseline to 3.5 +/- 0.3 cm2 near term, decreasing to 3.2 +/- 0.3 cm2 postpartum (p less than 0.002 for both). Heart rate increased from 70 +/- 7 to 77 +/- 10 beats/min near term decreasing to baseline postpartum (p less than 0.02 for both). Accordingly, cardiac output increased significantly, as detected from both the apical and suprasternal positions averaging from 4.7 +/- 0.6 to 6.5 +/- 1.5 l/min near term, returning to 4.3 +/- 0.6 l/min postpartum (p less than 0.0005 for both). Thus, in normal pregnancy, left atrial size increases significantly without significant changes in LV dimensions, volumes, and ejection fraction. Increased LV mass is related to increased body weight. Cardiac output changes result from increased heart rate and an increase in LV outflow area, which contributes to increased stroke volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Protamine alters apical membrane K+ and Cl- permeability in gallbladder epithelium.

Protamine addition to the solution bathing the mucosal side of Necturus gallbladder epithelium (25-100 mg/l) caused depolarization of both cell membranes, a mucosa-negative change in transepithelial voltage, an increase in the apical membrane resistance (Ra) followed by a decrease, and a monotonic increase in transepithelial resistance (Rt). In protamine (25 mg/l), the change in apical membrane voltage elicited by elevating mucosal solution [K+] from 2.5 to 92.5 mM was reduced from 66 +/-2 to 38 +/- 5 mV (P less than 0.001). The K+-induced fall in Ra was also reduced in protamine. These effects could also be elicited by elevating mucosal solution [K+] simultaneously with the addition of protamine and by transient addition of protamine during exposure to the high K+ medium. The effect of protamine on the electrodiffusive Cl- permeability of the apical membrane (PCl) was studied both in control and forskolin-treated tissues. In the absence of forskolin, the hyperpolarization of Vmc produced by lowering mucosal [Cl-] to 10 mM was reversed to a small depolarization; in forskolin, the initial depolarization produced by lowering [Cl-] was significantly increased. Finally, exposure to protamine in the absence of forskolin produced an initial fall in intracellular Cl- activity. Our results indicate that protamine decreases apical membrane K+ permeability and increases apical membrane PCl. The time course of the effects of protamine suggests the possibility of an initial effect on surface potential, followed by secondary actions mediated by intracellular events.

Animals↗
PubMed1984

Intraoperative urinary output does not predict postoperative renal function in patients undergoing abdominal aortic revascularization.

To determine whether intraoperative urinary output was predictive of postoperative renal function, mean urinary output and lowest hourly urinary output were measured in 137 patients during operation for aortic reconstruction. Pulmonary capillary wedge pressure was kept within normal limits. If urinary output was less than 0.125 ml X kg-1 X hr-1, patients were given crystalloid solution, mannitol, furosemide (Lasix), or nothing. For each patient, serum creatinine and blood urea nitrogen (BUN) levels were assayed on postoperative days 1, 3, and 7. There was no significant correlation between intraoperative mean urinary output or lowest hourly urinary output and change from preoperative to postoperative levels of creatinine or BUN. Twenty-one patients had postoperative renal insufficiency; of these, 17 had had renal disease before operation. In these patients as well; mean urinary output and the lowest hourly urinary output did not correlate with change in BUN or creatinine levels. The position of the aortic cross-clamp did not affect these correlations. Therefore, intraoperative urinary output was not predictive of postoperative renal insufficiency in patients undergoing aortic reconstruction.

Anuria↗
PubMed1980

Effect of mineralocorticoid replacement therapy on renal acid-base homeostasis in adrenalectomized patients.

Chronic balance studies were performed in six adrenalectomized patients to investigate the renal and systemic acid-base consequences of mineralocorticoid deficiency in the absence of either glucocorticoid deficiency or parenchymal renal disease. Constant glucocorticoid replacement was provided with dexamethasone, 750 to 875 micrograms/day, administered orally. Creatinine clearance averaged 98 +/- 8 ml/min/1.73 m2. Following a control period, mineralocorticoid replacement with fludrocortisone (100 to 200 micrograms/day) was either discontinued (N = 3) or initiated (N = 2). In an additional patient, mineralocorticoid replacement was initiated and sustained (5 days) by continuous i.v. infusion of aldosterone, at a dose approximating the normal secretion rate (120 micrograms/day). Net acid excretion (NAE) and plasma total carbon dioxide decreased in each patient in whom mineralocorticoid was discontinued and increased in each patient in whom mineralocorticoid was initiated. The cumulative change in NAE (sigma delta NAE) independent of direction averaged 66 +/- 20 mEq (P less than 0.05) by the fifth experimental day in the six patients, and the corresponding change in plasma total CO2 averaged 1.2 +/- 0.3 mmoles/liter (P less than 0.02). The magnitude of sigma delta NAE correlated with the basal rate of NAE (r = 0.87, P less than 0.05), which averaged 0.9 +/- 0.1 mEq/kg body wt per day. The change in plasma total CO2 correlated with sigma delta NAE (r = 0.83, P less than 0.05). The changes in NAE correlated positively with the corresponding changes in sodium balance and negatively with the corresponding changes in potassium balance. These findings provide the first evidence that renal acidification is under tonic stimulation by mineralocorticoid at levels not exceeding those in normal subjects ingesting acid-producing diets of normal sodium and potassium content. The extent to which the tonic stimulation of renal acidification is mediated by a direct effect of mineralocorticoid on renal hydrogen ion transport or by an indirect effect dependent on altered renal sodium and/or potassium transport requires further investigation. The findings implicate mineralocorticoid deficiency as a significant renal acidosis-producing condition not dependent on the presence of renal disease or glucocorticoid deficiency, and potentially amplified when endogenous acid production is increased by diet or disease.

Acid-Base Equilibrium↗
PubMedDate not supplied

Nitrous oxide, nausea, and vomiting after outpatient gynecologic surgery.

Postanesthetic nausea and vomiting can delay discharge of outpatients and can cause occasional admissions to hospital. Nitrous oxide (N2O) has been thought to increase this frequency, but previous studies have been indecisive. One hundred eighty-five unpremedicated outpatients undergoing laparoscopic tubal ligation were studied to determine the effect of N2O on postanesthetic nausea and vomiting. The patients were divided by registration number, intubated, and given mixtures of either N2O-O2 enflurane or air-O2 enflurane. Intravenous (IV) lidocaine, administered initially prior to intubation to control bucking, was later omitted in randomly chosen cases to determine its effect. The overall prevalence of nausea and vomiting was 29.2% with N2O and 9.3% with air (p less than 0.001). While the lidocaine subseries was small, it appeared to prevent nausea and vomiting, particularly when N2O was omitted. Further study is justified. Fentanyl, given postoperatively for pain, did not increase the prevalence of nausea and vomiting. It was concluded that N2O is associated with an increased prevalence of nausea and vomiting.

Adult↗
PubMedDate not supplied

Mivacurium as an alternative to succinylcholine during outpatient laparoscopy.

STUDY OBJECTIVES: To compare (1) the adequacy of conditions for tracheal intubation; (2) the onset, depth, clinically effective duration, and recovery profile; and (3) adverse effects associated with mivacurium as an alternative to succinylcholine during general (endotracheal) anesthesia for outpatient laparoscopy. DESIGN: A randomized, controlled clinical trial. SETTING: Barnes Hospital Outpatient Surgery Center. PATIENTS: Sixty healthy consenting ASA physical status I or II adult female outpatients. INTERVENTIONS: Following a standardized thiopental sodium-alfentanil induction, patients were randomly assigned to one of three groups: Group I-alfentanil-nitrous oxide (N2O)-succinylcholine; Group II-alfentanil-N2O-mivacurium; Group III-enflurane-N2O-mivacurium. MEASUREMENTS AND MAIN RESULTS: Neuromuscular blockade was measured by electromyography of the stimulated adductor pollicis muscle contraction. Tracheal intubation was attempted after achieving 70% or greater blockade and was graded on a four-point scale. Onset and recovery were more rapid with succinylcholine than with mivacurium. The clinically effective duration of action of mivacurium was not significantly different in the enflurane-N2O group compared with the alfentanil-N2O group. Side effects with mivacurium included flushing and occasional wheezing. CONCLUSIONS: Mivacurium 0.15 mg/kg given intravenously provided good to excellent conditions for tracheal intubation in 2 to 3 minutes. This dose provided a clinically effective duration of action of 20 to 25 minutes, and the residual blockade was readily reversible with neostigmine. Mivacurium did not, however, offer any apparent advantage over succinylcholine in this outpatient population.

Adult↗