Pratap S. Avasthi

Temporal Profile of Serum Potassium Concentration in Nondiabetic and Diabetic Outpatients on Chronic Dialysis

We analyzed routine serum potassium concentration measurements and conditions temporally associated with abnormalities in potassium concentration in outpatients on chronic hemodialysis (136 nondiabetics, 36 diabetics) and continuous ambulatory peritoneal dialysis (16 nondiabetics, 10 diabetics). The following potassium concentration frequencies were found: prehemodialysis, nondiabetics: normal 51.3%, severe hyperkalemia (greater than 6.0 mmol/l) 10%, severe hypokalemia (less than 3.0 mmol/l) 0.3%; diabetics: normal 57.8%, severe hyperkalemia 8.7%, severe hypokalemia 0.5%. Peritoneal dialysis, nondiabetics: normal 73.7%, severe hyperkalemia 0.6%, severe hypokalemia 4.9%; diabetics: normal 72.5%, severe hyperkalemia 0.9%, severe hypokalemia 2.9%. Normokalemia and severe hypokalemia were significantly (chi 2 test) more frequent in peritoneal dialysis than in prehemodialysis, whereas severe hyperkalemia was more frequent in prehemodialysis serum samples. No difference was found between nondiabetics and diabetics for either form of dialysis. 50% of prehemodialysis episodes of hyperkalemia were diet-induced. Hyperkalemic drugs and anuria were not associated with a higher risk of prehemodialysis hyperkalemia, but each one of 3 abnormalities, very high BUN (greater than 40 mmol/l), metabolic acidosis (TCO2 less than 15 mmol/l) and, in diabetics, severe hyperglycemia (serum glucose greater than 30 mmol/l), was associated with a statistically higher risk of hyperkalemia.

The relationship between glycemic control and morbidity and mortality for diabetics on dialysis.

This study was conducted to determine the association between glycemic control and clinical outcomes of diabetic patients maintained on chronic dialysis. The study group consisted of 226 diabetics (60 Type I and 166 Type II) classified as having either good glycemic control (>5 0% of blood glucose determinations within 3.3-11.1 mmol/L) or poor glycemic control (<50% of blood glucose measurements >3.3 and <11.1 mmol/L). The following variables were analyzed in each group: demographics; vascular and diabetic complications; laboratory values; and patient survival. In comparison to diabetics with poor control (Type I, n=44; Type II, n=57), those with good control, either Type I (n=16), or Type II (n=109), were dialyzed for longer periods and had shorter hospitalizations, lower prevalence rates of myocardial infarctions, congestive heart failure, orthostatic hypotension, gastroparesis and enteropathy, and higher mean serum albumin. Mean patient survival by life-table analysis was as follows: Type I diabetics, good control 128.9 + 8.1 months, poor control 29.5 + 5.0 months, p=0.0014. Type II diabetics, good control 56.9 + 6.8 months, poor control 22.8 + 4.6 months, p<0.0001. Good glycemic control during the first 6 months of dialysis predicted long-term survival for Type II but not for Type I diabetics. Poor glycemic control is associated with increased morbidity from vascular and diabetic complications, malnutrition, and shortened survival in diabetics on chronic dialysis. Although further studies are needed to determine whether poor glycemic control causes shortened survival or merely reflects comorbid conditions shortening survival, good glycemic control may constitute a Worthwhile therapeutic goal for diabetics on dialysis.

Femoral neck fractures in patients receiving long-term dialysis.

The morbidity and mortality of 11 femoral neck fractures were analyzed to compare operative and conservative management of femoral neck fractures in dialysis patients. All fractures occurred in older men with severe cardiac, pulmonary, gastro-intestinal, and neurologic conditions and with advanced renal osteodystrophy. Six of the seven operated patients survived the surgery and achieved varying degrees of ambulation. Stability of the operated hip was excellent in each case. Post-operative complications included transient confusional state related to narcotics, pneumonia, decubitus ulcers, and severe hypoalbuminemia. All four patients who were managed conservatively died from complications of the fracture. Progressive deterioration was noted in each nonoperated patient, with confusion caused by narcotics and analgesics, pneumonia, hepatic coma, decubitus ulcers, severe depression, and severe hypoalbuminemia. Therefore, operative management was superior to conservative management for femoral neck fractures of patients receiving chronic dialysis with multiple medical problems and advanced renal osteodystrophy. Narcotics must be used with great caution, and efforts should be directed toward prevention of malnutrition and decubitus ulcers.

Effect of Hyperglycemia on Serum Sodium Concentration and Tonicity in Outpatients on Chronic Dialysis

When serum glucose concentration is nearly normal, serum sodium concentration and tonicity are usually normal in ambulatory outpatient diabetics on chronic hemodialysis or peritoneal dialysis. In hyperglycemia, patients on hemodialysis do not undergo osmotic diuresis and are able to nearly normalize their serum tonicity by increasing the intake of water. Patients on peritoneal dialysis differ from hemodialysis patients because of continued loss of water in the peritoneal dialysate and achieve only partial correction of tonicity by water consumption. The model currently used to predict changes in serum sodium concentration and in tonicity from hyperglycemia assumes no changes in external balance of body water or solute during development of hyperglycemia and, therefore, is not applicable in ambulatory dialysis patients with intact thirst mechanism, because of water retention. In ambulatory patients on chronic dialysis, clinical manifestations of hyperglycemia include thirst, water intake, and weight gain. Neurologic manifestations due to hypertonicity are usually absent.

A comparison of echo-Doppler and electromagnetic renal blood flow measurements.

The linearity and accuracy of noninvasive ultrasonic method of measuring beat‐to‐beat renal blood flow was evaluated by correlation with standard electromagnetic flowmetry. Using a combined real‐time ultrasonic imager and pulsed Doppler velocimeter known as a duplex scanner (DS), lumen diameter (D) and average blood velocity (V) within the imaged renal artery were recorded. Renal blood flow ( QDS ) was calculated offline using a microprocessor from the equation QDS = (pi x D2 x V)/4. This noninvasive method had previously been validated in vitro using a controlled hydraulic system which modeled steady‐state flow (QT) where QDS = 0.98 QT + 7.75, SEE = +/‐ 13.2, r = +0.98, P less than 0.001. In three anesthetized dogs, simultaneous QDS and electromagnetic flow ( QEMF ) measurements (range 44‐484 ml x min‐1) were made in the proximal left renal artery. Linear regression analysis gave QDS = 0.43 QEMF + 40.5, r = 0.78, SEE = 33.8 ml x min‐1, P less than 0.01; QDS = 1.2 QEMF + 2.9, r = 0.86, SEE = 20.8 ml x min‐1, P less than 0.01; QDS = 0.86 QEMF + 0.2, r = 0.93, SEE = 53.4 ml x min‐1, P less than 0.01. These results suggest that noninvasive QDS measurements of renal blood flow are linear and reasonably accurate compared with invasive QEMF in dogs. The method may have utility in the noninvasive measurement of beat‐to‐beat blood flow in human renal arteries.

Gastroparesis in Diabetics on Chronic Dialysis: Clinical and Laboratory Associations and Predictive Features

Clinical and laboratory features and risk factors for diabetic gastroparesis (DGP) were investigated in 226 diabetics on chronic dialysis; 106 subjects (43%) had DGP diagnosed by persistent vomiting improved with the use of prokinetic agents and 120 (control group) had no clinical DGP. Type 1 diabetics had DGP more frequently than type 2 diabetics (70 vs. 37%). The DGP group had longer duration of diabetes (21 +/- 8 vs. 13 +/- 6 years), higher frequency of diabetic orthostatic hypotension (95 vs. 33%), enteropathy (49 vs. 5%), blindness (52 vs. 23%), myocardial infarction (86 vs. 42%), extremity gangrene (54 vs. 27%) and cerebrovascular accidents (43 vs. 25%), lower serum albumin 32.3 +/- 3.9 vs. 35.4 +/- 3.8 g/l), urea (24.0 +/- 5.5 vs. 25.5 +/- 5.5 mmol/l) and creatinine (710 +/- 210 vs. 820 +/- 220 mumol/l), and higher serum TCO2 (20.9 +/- 3.1 vs. 19.8 +/- 2.7 mmol/l) than the control group (all differences significant at p +/- 0.004). Glycemic control was adequate in 24% of the DGP group subjects and 83% of the control subjects (p < 0.001). Annual hospitalization rate was 49 +/- 48 days/patient in the DGP group and 16 +/- 27 days/patient in the control group (p < 0.001). Median patient survival was 24 +/- 2 months in the DGP group and 61 +/- 9 months in the control group (p < 0.0001). Logistic regression identified long duration of diabetes and poor glycemic control as risk factors for DGP. In diabetics on dialysis, DGP is associated with high frequency of other diabetic complications, low serum albumin and creatinine, and high morbidity and mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of 4% Chlorhexidine Gluconate in a Detergent Base (Hibiclens) and Povidone-Iodine (Betadine) for the Skin Preparation of Hemodialysis Patients and Personnel

The abnormal cutaneous flora of hemodialysis (HD) patients might contribute to their frequent septic complications. We compared the effects of 13 wk of Betadine and 13 wk of Hibiclens on the skin flora of HD patients and personnel. Skin cultures were obtained weekly immediately prior to the disinfection, preceding each triweekly HD treatment, and monthly, at 2 and 4 hr postdisinfection. Total bacterial counts from predisinfection cultures were not significantly altered over either 13-wk treatment period. Hibiclens reduced total bacterial counts (p less than 0.01) and eradicated cutaneous staphylococci (p = 0.032) at both 2 and 4 hr postdisinfection significantly more than did Betadine. No reduction of staphylococcal sensitivity to either germicidal agent could be demonstrated. Neither agent was associated with severe adverse reactions and Hibiclens could not be detected in the blood. Hibiclens appears to offer short-term advantages over Betadine in the HD setting because of significantly longer duration of antibacterial activity.

Hypoglycemia in diabetics on dialysis with poor glycemic control: hemodialysis versus continuous ambulatory peritoneal dialysis.

Eight diabetic men with poor glycemic control, probably worsened by severe congestive heart failure and gastroparesis, were sequentially dialyzed by CAPD and hemodialysis. Mean blood glucose concentration, blood glycosylated hemoglobin, and insulin dose were higher during CAPD than during hemodialysis. Among blood glucose determinations, however, the frequency of hypoglycemia (glucose <3.3 mmol/L) was higher during hemodialysis (13.2 ± 8.9%) than during CAPD (2.8 ± 2.1% p = 0.012), whereas the frequencies of hyperglycemia (glucose >11.1 mmol/L) and euglycemia (glucose between 3.5 and 11.1 mmol/L) did not differ between the two dialysis modalities. Furthermore, hypoglycemia was severe during hemodialysis and was associated with two deaths. There were no deaths linked to abnormalities in blood glucose concentration during CAPD. When hypoglycemia is frequent in diabetics with poor glycemic control, CAPD is preferable to hemodialysis.

Intraperitoneal thrombolytic agents in relapsing or persistent peritonitis of patients on continuous ambulatory peritoneal dialysis.

Urokinase or streptokinase was instilled intraperitoneally as an adjunct to the antibiotic therapy in 16 episodes of relapsing or persistent peritonitis in CAPD patients. In eight patients the combination of antibiotics and intraperitoneal thrombolytic agents resulted in clearing of the infection with no recurrences. The treatment failed in eight other patients, who had their peritoneal catheters removed. Six of the last eight patients had either abdominal wall abscesses or persistence of the bacteria on the wall of the peritoneal catheter. Elevated post-intraperitoneal instillation peritoneal fluid neutrophil counts and positive post-instillation peritoneal fluid cultures predicted failure of the intraperitoneal instillation of thrombolytic agents in most instances. Intraperitoneal instillation of urokinase or streptokinase may help cure approximately 50% of the episodes of relapsing for persistent peritonitis. Post-instillation peritoneal fluid cell counts and cultures should be monitored. Radiologic investigation for abdominal wall or intraabdominal abscesses is indicated if intraperitoneal instillation of urokinase or streptokinase fails to eradicate peritonitis.

Noninvasive Versus Invasive Doppler Renal Blood Velocity and Flow Measurements

We compared simultaneous noninvasive and invasive determinations of blood velocity and flow in the renal arteries of 5 mongrel dogs. Noninvasive measurements of blood velocity spectra (¿FN) were made using an ultrasonic echo-Doppler duplex scanner. Vessel diameters (DN) and Doppler angles (¿N) were measured from sector images of the renal artery. Invasive measurements of blood velocity spectra (¿F1) were made using a catheter Doppler velocimeter. Vessel lumen diameter (D1) and Doppler angle (¿1) were measured angiographically. Using the Doppler and continuity equations, temporal mean blood velocities (VN, V1) and flows (QN, Q1) of five cardiac cycles were calculated. The ranges of velocity (8-48 cm/s) and flow (40-380 ml/min) were varied by pharmacological intervention. Standard linear regressions (n = 33) were Results suggest that simultaneous noninvasive echo-Doppler and invasive catheter Doppler measurements of canine renal artery blood velocity and flow correlate significantly. Nevertheless, large standard errors of the estimates exist which suggest that important systematic and experimental errors are present in both methods.