Biomedical subjects

H I Winter

Publications and source records attributed to H I Winter.

5 recordsLinked to original sources

PubMed1995

The limited impact of involved surface area and surgical débridement on survival in Fournier's gangrene.

OBJECTIVE: To evaluate the influence of involved surface area (extent of disease) and the number and timing of surgical débridements on survival in patients with Fournier's gangrene. PATIENTS AND METHODS: The medical records of 30 patients with Fournier's gangrene treated over a 15-year period were reviewed. The extent of disease was quantified and expressed as a percentage of the body surface area by applying a modified diagram used to assess burn injuries. The number of surgical débridements and their timing with respect to initial presentation and to each other were also analysed. Patients were stratified by outcome (survival or death) and the data evaluated by Student's t-test, Fisher's exact test and regression analysis. RESULTS: Of 30 patients treated 13 died (43%) and 17 survived (57%). The mean surface area involved by disease among survivors was 4.3% (range 1-16.5%) and 7.2% (range 5-20.5%) for non-survivors (P = 0.10). Whilst no direct correlation between death rate and extent of disease existed, patients with < 5% surface area involvement were more likely to survive (P = 0.014). Every patient underwent surgical débridement of the involved area (mean 1.72 procedures per patient). Survivors underwent from one to four débridements (mean 1.79) and non-survivors one to three débridements (mean 1.63); the mean number of débridements did not influence outcome (P = 0.68). The performance of more than one débridement did not affect survival (P = 1.00). The initial débridement was performed within 24 h of presentation in 10 of 13 patients who died and 11 of 17 survivors and had no effect on outcome (P = 0.69). A second débridement was performed after a mean of 6.8 days (range 1-12) among the six survivors and 5.4 days (range 2-16) among the five non-survivors; this difference was not statistically significant (P = 0.65). Four survivors required a third débridement, one required a fourth and one patient who succumbed underwent a third débridement. CONCLUSION: The mortality rate from Fournier's gangrene continues to be substantial (43% in our series). Although no linear correlation existed, the quantified extent of disease may affect outcome as patients with > 5% of body surface area involved were more likely to succumb to the disease. Finally, the number of surgical débridements, even if first performed within 24 h of presentation, had no impact on outcome in patients with Fournier's gangrene.

Debridement↗

PubMed1995

Outcome prediction in patients with Fournier's gangrene.

We treated 30 patients with Fournier's gangrene during a 15-year period. Data were collected on demographics, medical history, admission signs and symptoms, physical examination, admission laboratory studies and bacteriology. The timing and degree of surgical débridement as well as antibiotic therapy were also reviewed. The extent of disease was calculated from body surface area nomograms. Data were stratified according to the outcomes of death (13 patients) or survival (17). Patients who survived were significantly younger (53 years old, range 23 to 90) than those who died (71 years old, range 53 to 83, p = 0.004). Admission laboratory parameters that were statistically related to outcome included hematocrit, blood urea nitrogen, calcium, albumin, alkaline phosphatase and cholesterol levels. White blood count, platelets, potassium, bicarbonate, blood urea nitrogen, total protein, albumin and lactic dehydrogenase levels 1 week following hospitalization were also associated with outcome. The greater mean extent of body surface area involved among patients who died was not statistically different from that of those who lived (7.16 and 4.32%, respectively, p = 0.1). The number of surgical débridements did not seem to influence outcome. To assess better the physiological profile of the patients in both outcome categories, the acute physiology and chronic health evaluation II severity score was modified to create a Fournier's gangrene severity index. The mean Fournier's gangrene severity index for survivors was 6.9 +/- 0.9 compared to 13.5 +/- 1.5 for nonsurvivors. Regression analysis demonstrated a strong correlation between Fournier's gangrene severity index and death rate (correlation coefficient = 0.934, p = 0.005). Using a Fournier's gangrene severity index threshold value of 9, there was a 75% probability of death with a score greater than 9, while a score of 9 or less was associated with a 78% probability of survival (p = 0.008). In conclusion, Fournier's gangrene is an infectious disease affecting an ever aging population of patients. Deviation from homeostasis is the most important parameter predictive of outcome and not the extent of disease or performance of surgical débridement. The Fournier's gangrene severity index is an objective and simple method to quantify the extent of metabolic aberration that may be used to predict outcome. We recommend the use of the Fournier's gangrene severity index when evaluating therapeutic options and reporting results.

APACHE↗

PubMed1991

Preoperative prostate-specific antigen in predicting pathologic stage and grade after radical prostatectomy.

Preoperative serum prostate-specific antigen (PSA) was measured in 63 men who had clinically localized, previously untreated adenocarcinoma of the prostate and underwent subsequent radical prostatectomy and bilateral pelvic lymph node dissection. Pathologic stage and grade were correlated to the serum PSA value. Patients with organ-confined (P1, P2) and extracapsular (P3, P3N +) prostate cancer had elevated preoperative serum PSA levels (greater than 4 ng/mL) in 61 and 90 percent of cases, respectively. Patients with low-grade and high-grade tumor histology had elevated preoperative PSA levels in 62 and 80 percent of cases, respectively. In distinguishing between organ-confined and extracapsular disease with a preoperative serum PSA of 10 ng/mL as a cutoff value, the sensitivity was 68 percent, the specificity was 66 percent, the positive predictive value was 46 percent, and the negative predictive value was 83 percent. Although there was a trend of increasing preoperative serum PSA levels with higher pathologic stage or grade, there was no significant difference in preoperative serum PSA values with pathologic stage and/or grade considered as a group or in determining stage and/or grade preoperatively on an individual basis.

Adenocarcinoma↗

PubMed1982

Effects of salicylate on HCO-3/Cl- exchange across the human erythrocyte membrane.

Changes in extracellular pH (pHo) in human red cell suspensions were monitored in a stopped-flow rapid reaction apparatus. A 20% suspension of washed human RBC in saline at pH 7 containing NaHCO3 and extracellular carbonic anhydrase was mixed with an equal volume of buffered saline solution at pH 6.7. Sodium salicylate, when present, was added to both the erythrocyte suspension and the buffer solution. The effects of salicylate in the therapeutic to toxic concentration range on HCO-3/Cl- exchange were studied at 37 degree C. HCO-3/Cl- exchange flux was estimated using the extracellular buffer capacity and the difference between dpHo/dt using a control RBC suspension and that using a suspension of RBC whose anion exchange pathway was markedly inhibited. The results show that salicylate competitively decreases the rate of HCO-3/Cl- exchange, with inhibition increasing as salicylate concentration increases. KI is approximately 2.4 mM. At a salicylate concentration of 10 mM, HCO-3/Cl- exchange under the conditions of our experiments was inhibited by more than 70%. These findings are consistent with the possibility that CO2 transfer in capillary beds in vivo may be diminished in the presence of salicylate due to slowing of red cell HCO-3/Cl- exchange.

Bicarbonates↗

PubMed1981

Effects of inhibition of RBC HCO3-/Cl- exchange on CO2 excretion and downstream pH disequilibrium in isolated rat lungs.

To determine the effects of the speed of the erythrocyte membrane chloride shift on pulmonary gas transfer, CO2 exchange and the kinetics of pH equilibration were measured with isolated rat lungs perfused with 20% suspensions of human erythrocytes. The lungs were ventilated with room air, and the inflowing perfusate blood gases were similar to those in mixed venous blood in vivo. All experiments were performed at 37 degrees C. Rates of CO2 excretion were determined by measuring the fraction of CO2 in mixed expired gas in a steady state. The time-course of extracellular pH equilibration in the effluent perfusate was measured in a downstream stopflow pH electrode apparatus. CO2 excretion was reduced by approximately 16% when the lungs were perfused with suspensions containing erythrocytes whose HCO-3/Cl- exchange rates was inhibited, compared with CO2 excretion when the lungs were perfused with normal erythrocyte suspensions. A fall of 0.06 in effluent perfusate extracellular pH was noted during perfusion with inhibited erythrocyte suspensions, in contrast to no observable downstream pH change during perfusion with normal erythrocyte suspensions. These results are in close agreement with the predictions of a theoretical model. Our observations suggest that CO2 transfer in capillary beds will be adversely affected in vivo when the rate of the erythrocyte HCO-3/Cl- exchange is abnormally low. Since a number of commonly used drugs are known to inhibit the chloride shift in human erythrocytes, these findings may have important clinical implications, especially in patients with impaired lung function.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗