Robert E. Lynch

Effects of Hemodialysis and Dimercaprol in Acute Dichromate Poisoning

A 22-month-old infant died after ingesting sodium dichromate his father had brought from work. Treatment included folic acid and dimercaprol administration, hemodialysis, and exchange transfusion. To evaluate this treatment, four dogs were hemodialyzed after receiving intravenous sodium dichromate: their dialyzer chromate clearance was similar to their renal chromate clearance and their dialyzer chromate clearance was not significantly different before or after dimercaprol administration. This and other cases in the literature indicate that although chromate poisoning is often fatal, supportive care, forced diuresis, and chelating agents may be helpful. Hemodialysis may be required if renal failure occurs. Awareness of toxicity and prevention remain the most important approaches.

Methadone-Induced Rigid-Chest Syndrome After Substantial Overdose

We report here the case of an infant who developed life-threatening rigid-chest syndrome after receiving an accidental overdose of methadone. The child responded to narcotic reversal. Pediatric physicians should be aware of this possible complication.

Sodium Reabsorption during Intrarenal Diazoxide Infusion in the Dog

Infusion of diazoxide, a potent benzothiazide antihypertensive, into the renal artery results in diuresis and natriuresis. The site within the nephron of decreased reabsorption has been controversial. Thus free flow recollection micropuncture studies of the superficial proximal tubule of the dog were undertaken to determine if diazoxide decreased sodium reabsorption from this part of the nephron. Renal blood flow, monitored by an electromagnetic flow meter, was increased by about 15% with the diazoxide infusion. Systemic blood pressure and hematocrit remained unchanged. Glomerular filtration rate increased significantly from 26 +/- 2 to 34 +/- 3 ml/min, urine flow and sodium excretion also increased (0.13 +/- 0.01 to 0.33 +/- 0.06 ml/min and 5.5 +/- 0.90 to 35.5 +/- 11.0 microEq/min, respectively). Decreased sodium reabsorption from the proximal tubule was demonstrated by a decrease in the tubular fluid to plasma inulin ratio (1.62 +/- 0.1 1.47 +/- 0.1) thus giving a reduction in fractional sodium reabsorption to the site of micropuncture (36.1 +/- 4.3 to 29.5 +/- 5.1%, p less than 0.05). To examine peritubular effects of diazoxide infusion, capillary protein concentration and pressure were measured; the former increasing significantly (9.17 +/- 0.32 to 9.80 +/- 0.35, p less than 0.05) and the latter did not change (13.1 +/- 1.0 vs. 15.2 +/- 1.4 mm Hg). Thus intrarenal diazoxide causes whole kidney vasodilatation with diuresis, natriuresis and decreased sodium reabsorption from the superficial proximal tubule. Additional studies provided no data to indicate that changes in peritubular physical factors account for the changes in sodium handling.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Evaluation of the Kidney in Systemic and Collagen Diseases

The specialized nature of the renal vasculature and the relatively large renal blood flow make kidney damage particularly likely whenever systemic illness threatens the patient’s vascular integrity. Involvement may be minor, or kidney failure and homeostatic catastrophe may result.