Do burn patients have a silver lining?

Silver-containing pharmacological preparations have been used for many years in the prophylaxis and management of burn wound sepsis and, more recently, 1 per cent silver sulphadiazine cream (SSD) has been the treatment of choice for such problems. A prospective clinical study has been undertaken to determine the absorption and effects of the silver ion from SSD, with particular reference to hepatic and renal function. Twenty-two patients were studied. The silver assay was done by atomic absorption spectrophotometry with an attached graphite furnace. The detection level was 0.5 micrograms/l. The precision at 3.5 micrograms/l was 4.8 per cent and at 8.5 micrograms/l was 2.8 per cent. Silver was rapidly absorbed through the burn wound and serum silver levels were elevated in 20 patients. Silver was found to be deposited biochemically and electronmicrographically in the liver and kidneys of the only patient who died in the study group. Early hepatic dysfunction was present in all burns greater than 10 per cent total body surface area. Liver and renal function tests did not correlate with serum silver levels. A urinary threshold to silver excretion was seen at a serum silver level of 100 micrograms/l. This study demonstrates that silver is rapidly absorbed through burn wounds, is deposited in large amounts throughout the body but appears safe when used in the treatment of moderate burns. Whether the very high levels recorded in the subject who died were inherently detrimental will remain a matter for speculation.

Determination of silver in blood, urine, and tissues of volunteers and burn patients.

Silver sulfadiazine cream (SSD) has been used successfully in the management of burn wound sepsis. Silver deposition has been found in the skin, gingiva, cornea, liver, and kidney of patients treated with this cream, causing argyria, ocular injury, leukopenia, and toxicity in kidney, liver, and neurologic tissues. Monitoring concentrations of silver in blood and urine of patients receiving this treatment has become necessary, but sensitive and suitable methods adaptable to a clinical laboratory are still needed. We have developed a flameless thermal atomic absorption spectrophotometric method to measure silver concentrations in blood, urine, and other tissues. The detection limit is 0.4 microgram/L; the within-run precisions (CV) are 5.16%, 3.83%, and 2.79% for concentrations of 5, 13.5, and 42 micrograms/L, respectively; and the between-run precisions are 4.3% and 3.2% for concentrations of 13.5 and 42 micrograms/L. The concentrations of silver in blood, urine, liver, and kidney of subjects without industrial or medicinal exposure are less than 2.3 micrograms/L, 2 micrograms/day, 0.05 microgram/g wet tissue, and 0.05 microgram/g wet tissue, respectively. In SSD cream-treated burn patients, plasma concentrations may be as great as 50 micrograms/L within 6 h of treatment and can reach a maximum of 310 micrograms/L. Silver in urine is detectable after one day of treatment and may reach a maximum of 400 micrograms/day. After absorption, silver was found to be deposited in various tissues. Tissue silver concentrations in one burn patient who died of renal failure after eight days of treatment were 970, 14, and 0.2 micrograms/g wet tissue in cornea, liver, and kidney, respectively.

Absorption and elimination of bismuth from oral doses of tripotassium dicitrato bismuthate.

The pharmacokinetics of bismuth subcitrate were studied in plasma and urine under conditions of single and multiple dosing (28-56 days) using atomic absorption technique. Single dose plasma pharmacokinetics showed peak concentrations of 5.5-57.5 micrograms.l-1 (mean = 24.7 micrograms.l-1), reached between 30 and 60 min post dosing with an apparent biphasic elimination pattern. Multiple dose studies showed a continuing rise in plasma concentration and urine excretion rate reaching apparent steady-state levels over 7-29 days (mean = 18 days). Washout studies in 6 individuals reciprocated accumulation. Maximum equilibrated plasma levels of 7.6-58.3 micrograms.l-1 (mean = 38.3 micrograms.l-1) were well below those associated with encephalopathy. The half-life of bismuth elimination was 20.7 days. Present patterns of intermittent dosing with bismuth are unlikely to be associated with bismuth accumulation despite slow accumulation and elimination.

Improved assay for bismuth in biological samples by atomic absorption spectrophotometry with hydride generation.

This simple, rapid, sensitive, reliable, and economical assay for bismuth in plasma, erythrocytes, and urine is based on atomic absorption spectrophotometry with hydride generation. Acid digestion eliminates the problem of foaming, which hitherto has complicated such assay of bismuth in plasma and erythrocytes. The detection limit of the assay has been improved to 0.1 micrograms/L, as compared with a previously documented limit of 2.5 micrograms/L. Average recovery exceeded 95% in all biological fluids. Economy of use derives from elimination of need for electrodeless discharge lamps and atomic absorption grade borohydride. Determination of basal concentrations of bismuth in clinical samples of body fluids gave reference intervals of 0.1-3.5 micrograms/L for plasma, 0.3-4.6 micrograms/L for urine.

Myocardial infarct imaging after cardiac surgery.

One hundred and nineteen patients undergoing cardiac surgery had postoperative myocardial imaging performed with technetium pyrophosphate in order to assess the incidence of perioperative myocardial infarction. Fifty-six patients had only coronary artery bypass graft (CABG) surgery, of whom 13(23%) had a positive scintigram. Thirteen patients had CABG with other cardiac surgery and six (46%) had a positive scintigram. Fifty patients had other cardiac surgery but no CABG, and of these eight (16%) had a positive scintigram. The overall incidence of positive scintigrams was 23%, whereas definite or probable ECG diagnosis of infarction was present in 14 patients (12%). Serum levels of cardiac enzymes were higher in patients with positive scintigrams, but this finding did not consistently reach statistical significance. The use of a left ventricular vent during surgery did not correlate with a positive scintigram, nor did the total time on cardiopulmonary bypass or aortic cross-clamping. Patients having cardiac surgery, including CABG and valve replacement, have a 23% overall incidence of positive scintigrams. This suggests that the incidence of infarction after cardiac surgery is higher than can be recognized from the conventional criteria of ECG and enzyme changes.

Acute hemorrhagic pancreatitis in the dog. IV. Treatment with vasopressin.

Acute hemorrhagic pancreatitis was experimentally induced in the dog by the closed-duodenal-loop technique. The disease process was modified and partially reversed by intravenous infusions of vasopressin, as indicated by some of our tests for pancreatitis as well as histologic examination of the pancreas.