Serum Iodine Levels Research Articles

Comments Regarding “Subclinical Hyperthyroidism in Cats: A Spontaneous Model of Subclinical Toxic Nodular Goiter in Humans?”

We would like to comment on some of the points made by Wakeling et al. in their manuscript entitled ‘‘Subclinical Hyperthyroidism in Cats: A Spontaneous Model of Subclinical Toxic Nodular Goiter in Humans?’’ (1). The authors state: ‘‘The purpose of this study was to determine whether a relationship exists between TSH concentration and thyroid histopathology in biochemically euthyroid cats (as assessed by tT4 [serum total T4 concentration] thereby providing further evidence for the existence of subclinical hyperthyroidism in cats.’’ We certainly support the idea that the histopathological changes associated with spontaneous feline hyperthyroidism provide a model of toxic nodular goiter (Plummer’s disease), and have contributed to the literature in this regard (2–4). Undoubtedly, there is a prodromal period for this disease associated with clinically and biochemically undetectable hyperthyroidism. However, the authors of this manuscript have chosen a ‘‘healthy’’ population dominated by cats with chronic renal disease which we propose confounds the interpretation of their data. The concern rises from the observation in human patients with chronic kidney disease, both before as well as following kidney transplantation, that there is an increased frequency of goiter and thyroid adenomas (as well as hypothyroidism, probably due to increased serum iodine levels). In one study (5) of patients with chronic renal disease, the incidence of abnormal thyroid structures (nodules or abnormal echogenicity on ultrasound) in patients before or chronically after transplantation was 63=70% with 13=17% having goiter. The control group with normal renal function had 29%=16%, respectively. Despite the increased tendency for nodules, the thyroid volume was not significantly altered in the chronic kidney disease patients. A second concern is the reliance on the heterologous canine TSH assay to characterize thyroid hyperfunction in these cats. The commercially available canine TSH assay does detect gross elevations of TSH in the cat, such as during methimazole therapy. The assay has a sensitivity limit of 0.03 ng=mL that translates to about 0.1 ng=mL (very close to 1 mU=L) when corrected for 36% crossreactivity to recombinant feline TSH (6,7). Therefore, as was true for firstgeneration human TSH assays, on a case-by-case basis, a normal concentration cannot be reliably distinguished from an undetectable value. The authors quote from ‘‘unpublished data’’ (now published in reference 8) from 90 cats that the reference range for healthy senior cats is 7 years of age had detectable TSH. The authors note: ‘‘However, it is likely that not all cats with TSH <0.03 ng=mL have subclinical hyperthyroidism, particularly cats with severe concurrent illness and young cats.’’ Of the 59 cats for which there was histopathological data, 41 had chronic kidney disease and 13 were young cats. Therefore, 54=59 or 91.5% of the cases fit the categorization over which they raise concern. The authors continue: ‘‘In particular, it is known that kidney disease suppresses thyroid hormone production in cats and that the degree of suppression of tT4 is related to the severity of the concurrent disease (25).’’ As one of us was an author on this study (9), we would state that while the depression of serum total T4 concentration was observed, no measurement of thyroid hormone production per se was undertaken. The authors state that because creatinine was similar in the normal TSH and high TSH groups, and body weight and liver enzymes were similar, there were no differences in the populations. Aside from the effects of a chronic illness, uremia per se will be a major contributor to altering thyroid hormone metabolism, in part through alteration of serum T4 binding. No free T4 measurements were provided in the current study to evaluate this possibility, but the subsequent publication by the authors (8) supports this hypothesis in cats: the median free T4 concentration in the group with chronic kidney disease was only slightly higher than that of normal euthyroid population while the median total T4 concentration

A high dietary iodine increases thyroid iodine stores and iodine concentration in blood serum but has little effect on muscle iodine content in pigs

There is still iodine deficiency in many populations, which justifies efforts to increase this trace element in food such as milk, eggs and meat by fortifying compound animal feeds with extra iodine. The iodine requirement of growing pigs is in the order of 100–200 μg/kg feed (as a supplement) and the effects of this dosage range or higher on pork iodine concentration should be determined including the action of relevant iodine antagonists in feed, e.g., rapeseed. In three experiments on a total of 208 pigs [Pietrain × (Landrace × Large White)] the iodine concentration of meat (m. longissimus) – 71 samples –, blood serum – 100 samples – and of the thyroid – 100 samples – was analysed by intracoupled plasma-MS. In Experiment 1, 4 × 10 pigs received diets without or with rapeseed cake (0 and 3.2 mmol glucosinolates/kg diet) either with 125 or with 250 μg iodine/kg. In Experiment 2, the three groups with 46 pigs each were fed high iodine diets (1200 μg supplementary iodine/kg) without or with 100 or 150 g solvent extracted rapeseed meal/kg diet (0; 0.8 and 1.2 mmol glucosinolates/kg). In Experiment 3, 3 × 10 pigs received either 600 μg iodine/kg feed (1) or the 5-fold dosage (600 + 2400 μg iodine/kg diet) administered 7 days (2) or 18 days (3) before slaughtering. The group means of pork iodine content were in the relatively small range from 3 to 16 μg/kg, which contrasted to the enormously varying dosage range from 125 to 3000 μg iodine/kg diet. There was a certain iodine dosage effect in Experiment 3 when – in comparison to the control – a 3-fold higher meat iodine concentration resulted from a 5-fold higher diet iodine concentration. In Experiment 1 with the low iodine offer, rapeseed cake with glucosinolates decreased the serum iodine level whereas in Experiment 2 this did not happen due to higher iodine fed and lower glucosinolates exposure. The thyroid iodine reflected the dietary iodine better than blood serum iodine and the serum better than muscle. However, in Experiment 2, 1200 μg iodine/kg diet produced only half the serum iodine concentration than half as much dietary iodine in Experiment 3 (600 μg iodine/kg diet), which may result from rapid elimination of blood iodine and a higher urinary excretion by longer duration of feed withdrawal before blood sampling. The muscle of pigs has to be classified as a low iodine food. Thus, there are no possibilities to concentrate this trace element reproducibly in amounts relevant for human nutrition in pork.

Evaluation of the tranquilliser trap device (TTD) for improving the humaneness of dingo trapping

AbstractPredation of sheep and cattle by the dingo (Canis lupus dingo) is implicated in significant stock losses throughout much of mainland Australia. Leg-hold traps are commonly used for dingo control and ways are sought to improve the humaneness of these devices. We evaluated the performance of the tranquilliser trap device (TTD) attached to Victor Soft-Catch®traps for their ability to deliver a sedative and anxiolytic drug to trapped dingoes. A trapping programme was conducted in south-west Queensland where traps were set alternatively with a TTD containing either 800 mg of diazepam (drug TTD) or a placebo (placebo TTD). All TTDs included 20 mg of the bait marker iophenoxic acid (IPA) to ascertain dosing success. Each trap was fitted with an activity-monitoring data logger that recorded time of capture and subsequent dingo activity. In 41 out of 48 (85.4%) captures the TTD was ruptured and released its contents. No elevation in serum iodine levels above I mg ml-1resulting from the ingestion of IPA occurred in 8 out of 36 (22.2%) captures, which suggests a higher rate of dosage failure. Dingo activity was highest in both groups immediately after capture, but declined after the first hour in each. The activity of dingoes that accepted a drug TTD was significantly reduced compared to those that took the placebo. However, tooth and limb damage scores did not differ significantly between the drug and placebo group. Much of the physical trauma may have occurred within the first hour of capture when activity was intense and before drug onset in the TTD drug group. The use of TTDs containing sedative and anxiolytic drugs has the potential to reduce anxiety and distress associated with prolonged captivity, but the delivery of a lethal agent that is rapidly acting and humane may result in better welfare outcomes.

Uptake of Baits by Red Foxes (Vulpes vulpes): Implications for Rabies Contingency Planning in Australia

Baits containing the bait marker iophenoxic acid were used to quantify bait uptake by red foxes in a rural environment in north-eastern New South Wales. Baits were distributed at a mean density of 4·4 baits km-2. Serum iodine levels were analysed from a sample of 29 foxes shot on two baited sites and a nil-treatment site. The mean percentage of foxes with elevated seral iodine, indicating the consumption of at least one bait, was 58·3%. This rate of bait uptake would not consistently deliver reductions in fox densities or immunisation levels considered necessary for the control of rabies enzootics in Europe and North America. The minimum number known to be alive (MNA) method overestimated population reduction and underestimated abundance. Indirect estimators of population abundance, such as bait-station indices, are of more use in rabies contingency planning and modelling. This is because they are more reliable, are likely to overestimate abundance, and are more precautionary. Shooting of foxes at night was an inefficient method of reducing fox populations.

Systemic iodine absorption during endoscopic application of radiographic contrast agents for endoscopic retrograde cholangiopancreaticography.

Hyperthyroidism induced by contrast agents in a major problem in patients with pre-existing thyroid disease, particularly in patients with functional thyroid autonomy. The present study was undertaken to evaluate whether contrast media applied during endoscopic retrograde cholangiopancreaticography (ERCP) may result in a significant increase of serum iodine levels and thus may be associated with the risk of iodine-induced hyperthyroidism. The courses of serum concentrations of total iodine and free iodide, as well as of urinary iodine excretion, were measured in 15 patients before and up to 21 days after ERCP. During ERCP, the non-ionic contrast medium iopamidol was instilled in amounts resulting in a total iodine load of 57.4 +/- 22.8 mmol (7.3 +/- 2.9 g). In all patients, ERCP resulted in a highly significant increase in serum levels of total iodine from 0.8 +/- 0.5 to 85.2 +/- 116.9 mumol/l 4 h after application of the contrast agent. In parallel, serum iodide levels were raised from 0.06 +/- 0.04 to 5.42 +/- 6.09 mumol/l and urinary iodine excretion from 71.1 +/- 35.7 mumol/mol creatinine to 621,620.9 +/- 636,492.2 mumol/mol creatinine. Peak concentrations of serum iodine are well related to the total amount of iodine applied (p < 0.05). During follow-up, iodine levels returned to pre-exposure levels within 2-3 weeks. Levels of thyrotropin, free thyroxine, and free triiodothyronine remained unchanged during the follow-up period. In conclusion, endoscopic application of iodinated contrast agents during ERCP leads to significant increases of serum levels of total iodine and free iodide and of urinary iodine excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

High-performance liquid chromatographic determination of iophenoxic acid in serum

Iophenoxic acid (IPA), a marker used to investigate the feeding behaviour of bait-consuming animals has previously been indirectly determined by measuring protein-bound iodine levels in serum or plasma. For the first time a method is reported for the direct determination of IPA in biological fluids. IPA was determined in de-proteinized serum by high-performance liquid chromatography (HPLC) on a C 18 column with a mobile phase of acetonitrile—water. Isocratic and gradient systems are described with limits of detection of 0.2 μg/ml (isocratic) and 0.05 μg/ml (gradient). Recoveries from fox serum were 85% at 0.5 μg/ml, 95% at 5 μg/ml and 91% at 50 μg/ml.

Reversible primary hypothyroidism and elevated serum iodine level in patients with renal dysfunction.

Recovery of thyroid function in patients with both thyroid and renal dysfunction was studied. Among 245 patients with primary hypothyroidism (serum TSH greater than 10 mU/l), 36 had mild to severe renal dysfunction (serum urea nitrogen greater than 7.1 mmol/l and creatinine greater than 106 mumol/l). Of these 36 patients, recovery of the thyroid function after iodine restriction was observed in 30 (83%), in whom an elevated serum non-hormonal iodine level (median 236, range 67-15,591 micrograms/l, N = 19) and a high thyroidal radioactive iodine uptake (51.5 +/- 29.3% at 24 h, N = 26) were observed. The perchlorate discharge test was positive in 7 of 13 patients examined, suggesting an iodide organification defect rather than an atrophic or destructive change in the thyroid. Antithyroid antibodies were negative in 22 patients (73%) and an almost normal thyroid gland or colloid goitre was confirmed histologically in 8 of them. After a 13.2 mg potassium iodide loading test, 24 h urinary excretion of iodine was about 60% in normal controls, but only 10% in a different group of six euthyroid patients with renal dysfunction. These findings suggest that impaired renal handling of iodine rather than autoimmune mechanism may have a significant role in the pathogenesis of reversible hypothyroidism found in patients with renal dysfunction, probably through a prolonged Wolff-Chaikoff effect.

Urinary Excretion of Iohexol after Enteral Administration in Rats with Radiation Injury of the Small Intestine

Gut membrane dysfunction after acute and subacute irradiation injury to 10-cm-long small-bowel segments was assessed in 85 rats receiving doses of 17 and 21 Gy. Four and 14 days after irradiation 2 ml iohexol was administered via orogastric tubes, and hourly radiographs were taken. After 8 h, blood and urine were sampled for testing, and the intestine biopsied for light and scanning electron microscopy. Dense opacification of the urinary bladder was seen on abdominal films, and increased serum and urinary levels of iodine were demonstrated by X-ray fluorescence analysis in irradiated animals. Urinary levels were up to 20 times higher than in controls 4 days after irradiation, subsiding after 14 days. The effects were prolonged in the 21-Gy group. Our results indicate that measurement of iodine levels in serum and urine may be helpful in assessment of bowel injury in the course of irradiation treatment to pelvic or abdominal organs.

Thyrotoxicosis Induced by Topical Iodine Application

We describe an elderly man who was admitted with congestive cardiac failure and found to have thyrotoxicosis. He did not have goiter, and he had normal radioiodine uptake in his neck. Serum iodine levels were elevated, explaining the lack of increase in radioiodine uptake in the thyroid gland. He had multiple pressure sores, which were treated with povidone-iodine (Betadine) soaks. Biochemical data were consistent with Graves' disease unmasked by topical iodine application. Povidone-iodine soaks are commonly used in decubitus ulcer care and warrant special attention in patients with preexisting thyroid disorders. We have reviewed the literature on this unusual complication.

Thyrotoxicosis induced by topical iodine application

• We describe an elderly man who was admitted with congestive cardiac failure and found to have thyrotoxicosis. He did not have goiter, and he had normal radioiodine uptake in his neck. Serum iodine levels were elevated, explaining the lack of increase in radioiodine uptake in the thyroid gland. He had multiple pressure sores, which were treated with povidone-iodine (Betadine) soaks. Biochemical data were consistent with Graves' disease unmasked by topical iodine application. Povidone-iodine soaks are commonly used in decubitus ulcer care and warrant special attention in patients with preexisting thyroid disorders. We have reviewed the literature on this unusual complication. (<i>Arch Intern Med.</i>1990;150:2400-2401)

Effects of Chronic Peritoneal Dialysis on Thyroid Function Tests

Peritoneal dialysis is associated with large losses of protein. In order to quantify thyroid hormone excretion in the dialysate and to examine the possibility that peritoneal dialysis may result in clinical hypothyroidism, nine endstage renal disease (ESRD) patients undergoing either continuous ambulatory peritoneal dialysis (CAPD) or chronic intermittent peritoneal dialysis (IPD) were studied. Total protein excretion in the peritoneal fluid was 21.5 +/- 2.1 g/24 h and did not vary with the mode of peritoneal dialysis. Thyroid binding globulin (TBG) excretion was 6.4 +/- 1.3 mg/24 h, higher than the values reported in the literature for urinary TBG excretion in patients with the nephrotic syndrome. Despite the higher TBG losses, serum TBG remained in the normal range. Mean peritoneal total T4 and T3 were 8.1 +/- 1.6 micrograms/24 h and 89.5 +/- 14.6 ng/24 h, and there was a significant correlation between peritoneal T4 and TBG (r = 0.69; P less than 0.01) and between peritoneal total proteins and T4 (r = 0.80; P less than 0.001). Despite the finding that large amounts of protein are lost in peritoneal fluid, T4 and T3 losses were relatively modest and remained below their daily production rates, and none of the patients were overtly hypothyroid. Serum thyroid stimulating hormone (TSH) was mildly elevated in three of nine patients and was consistent with early thyroid failure. The patients' serum iodine levels were higher than normal but did not predict the patients' thyroid status. We conclude that major protein losses could predispose patients undergoing CAPD to thyroid failure and that long-term follow-up of thyroid function is warranted in these patients.

Urinary Excretion of Iohexol after Intestinal Administration in Rats with Bowel Ischaemia

Serum and urinary levels of iohexol (Omnipaque) were evaluated in 28 rats after instillation of 1.5 ml of contrast medium directly into closed small bowel segments of equal length. Ten rats had a ligature applied to the anterior mesenteric artery and vein via laparotomy, 10 animals had a ligature of the vein only and 8 had no vascular occlusion (operated controls). In addition, 3 rats (non-operated controls, normals) were gavaged with a similar volume of the same contrast medium. Radiographs were obtained every hour. Biopsy samples and blood and urine tests were taken at the end of the 4-hour observation period. On radiographs, a marked increase of urinary bladder opacity was observed after 2 to 4 hours in the rats with both vessels tied. Correspondingly high iodine levels were measured in the urine and serum at 4 hours by x-ray fluorescence analysis. Urinary levels were 27 times and serum levels 8 times that of operated controls, respectively, and 81 and 25 times that of normals. Venous occlusion affected the bladder opacity to a lesser extent, giving urinary iodine levels 12 times and serum levels twice that of normal controls. Neither urinary nor serum iodine levels were significantly different from the operated controls. The operated controls had urinary concentrations of contrast medium 3 times that of the gavaged normal controls, but a barely visible urinary bladder on radiographs. Measuring iodine levels in serum or urine may be helpful in the evaluation of the degree of mucosal injury induced by intestinal ischaemia.

Iodine Retention and Thyroid Dysfunction in Patients on Hemodialysis and Continuous Ambulatory Peritoneal Dialysis

Povidone-iodine is frequently used as an antiseptic in patients on chronic dialysis. In order to determine if the use of povidone-iodine affects thyroid function in these patients, we measured serum iodine and thyroid hormone levels in dialysis patients prior to and following discontinuation of topical povidone-iodine antiseptics. Serum inorganic iodine levels were elevated initially in nearly 90% of the patients (19 on hemodialysis, 12 on continuous ambulatory peritoneal dialysis [CAPD]). Following discontinuation of povidone-iodine, iodine levels over a 3-month period decreased modestly in patients on CAPD (n = 5) and were unchanged in patients on hemodialysis (n = 5). Total and free thyroxine levels were frequently low but did not correlate with protein-bound or inorganic iodine levels and did not change after discontinuation of povidone-iodine. Thyrotropin levels correlated significantly (r = .62, P less than .01) with inorganic iodine levels in patients on hemodialysis, but not for patients on CAPD. We conclude that abnormal thyroid function tests are common in dialysis patients but are not related to iodine retention or to the routine use of topical povidone-iodine-containing antiseptics.

Randomised trial of intraperitoneal irrigation with low molecular weight povidone-iodine solution to reduce intra-abdominal infectious complications

A prospective randomized trial was performed comparing the efficacy of intraperitoneal irrigation with low molecular weight povidone-iodine solution ('Betadine LMW') (PVP-I LMW) in reducing the risk of intra-abdominal infectious complications. Seventy-five patients who were undergoing surgical procedures in the face of bacterial contamination were studied. Patients were intra-operatively randomized to receive intraperitoneal irrigation prior to abdominal closure with PVP-I LMW or with saline. Patients were maintained on peri-operative systemic antibiotics, and surgical incisions were drained and were closed primarily or left open according to the practice of the surgeon responsible. If incisions were closed, the subcutaneous tissue was irrigated prior to skin closure with the same irrigant as used intraperitoneally, PVP-I LMW or saline. Patients were followed for abnormal wound healing, peritonitis, intra-abdominal abscesses, or other infectious complications. Serum iodine levels were monitored in some patients. Intra-abdominal infectious complications developed in two of 37 patients receiving PVP-I LMW irrigation as compared to complications in nine of 38 patients receiving saline irrigation (P less than 0.05). When infectious complications were excluded that were possibly due to surgical technical failures (such as anastomotic leakage), peritonitis or intra-abdominal abscesses were observed in one of 37 PVP-I LMW patients and in seven of 38 saline control patients (P less than 0.05). Wound infections developed in one of 37 PVP-I LMW patients and in three of 38 control patients. A broad range of serum iodine levels were observed in control patients preoperatively and at 24 h and 7 days postoperatively. Serum iodine levels in 'Betadine LMW' patients rose approximately nine-fold by 24 h postoperatively and returned to pre-operative levels by 7 days. It was concluded that PVP-I LMW solution can reduce the incidence of intra-abdominal infectious complications when used as an intraperitoneal irrigant in patients undergoing bacterially-contaminated surgical procedures.

Vaginal absorption of povidone-iodine

In 12 nonpregnant women, total iodine, protein-bound iodine, inorganic iodine, and thyroxine values were measured in serum before and 15, 30, 45, or 60 minutes after a two-minute vaginal disinfection with povidone-iodine (Betadine). Only 15 minutes after application, serum iodine levels were raised and remained significantly elevated 30, 45, and 60 minutes after disinfection. Serum concentrations of total iodine and inorganic iodine were increased up to fivefold to 15-fold, respectively; during the relative short period of observation, thyroxine levels were not altered. An overload of iodine can suppress thyroid hormonogenesis, and the fetal and neonatal thyroid glands are especially sensitive. In pregnant women, vaginitis should not be treated with povidone-iodine because of the possible development of iodine-induced goiter and hypothyroidism in the fetus and newborn. The risk is especially high when povidone-iodine is used repeatedly. (<i>JAMA</i>1980;244:2628-2629)

Vaginal Absorption of Povidone-Iodine

In 12 nonpregnant women, total iodine, protein-bound iodine, inorganic iodine, and thyroxine values were measured in serum before and 15, 30, 45 or 60 minutes after a two-minute vaginal disinfection with povidone-iodine (Betadine). Only 15 minutes after application, serum iodine levels were raised and remained significantly elevated 30, 45 and 60 minutes after disinfection. Serum concentrations of total iodine and inorganic iodine were increased up to fivefold to 15-fold, respectively; during the relative short period of observation, thyroxine levels were not altered. An overload of iodine can suppress thyroid hormonogenesis, and the fetal and neonatal thyroid glands are especially sensitive. In pregnant women, vaginitis should not be treated with povidone-iodine because of the possible development of iodine-induced goiter and hypothyroidism in the fetus and newborn. The risk is especially high when povidone-iodine is used repeatedly.

A critical evaluation of povidone-iodine absorption in thermally injured patients.

Povidone-iodine ointment is a widely used topical antimicrobial agent in thermally injured patients. In 17 patients with burns ranging from 4 to 85% TBSA this agent was applied to both partial- and full-thickness burns. Peak serum iodine levels in patients treated within 24 hours of injury ranged from 595 to 4,900 micrograms per dL. The amount of iodine absorbed was directly related to the size of the burn. Serum iodine levels continued to rise until the drug was discontinued and remained elevated for as long as 7 days after discontinuance. Iodine excretion was directly related to renal function. The highest serum and lowest urinary iodine levels were present in patients who developed renal failure. Thyroid function was not affected by drug usage. A proven cause-and-effect relationship between the elevated serum iodine attributed to the absorption of povidone-iodine and metabolic acidosis, hypernatremia, and hyperosmolarity was not established. Close monitoring of the patient's fluid and electrolyte balance is imperative during drug usage. The drug is contraindicated in any patient with impaired renal function. The high serum levels of this inorganic ion imply potential toxicity, but clinical evidence of cell or organ toxicity is as yet undetermined.

The Renal Excretion of Iodine Following Oral Administration of Gastrografin to Domestic Cats

Serum and urinary levels of iodine were determined in six cats before and after oral administration of Gastrografin. Iodine was identified by gamma spectrometry after the specimens had been subjected to neutron activation. Peak serum iodine levels, compared to undetectable preadministration levels in five of the six cats, ranged from 8.0 to 50.7 micrograms/ml 1 to 2 hours after Gastrografin administration. Twenty-four hour cumulative urinary excretion of iodine represented 0.9 to 4.08% of this element calculated to be in Gastrografin. Pharmacokinetic analysis of the serum concentrations using the one-compartment open model resulted in an estimate of ka, the fraction of Gastrografin dose absorbed per unit time, of 2.24 hr-1 (95% CL = -5.4, 7.7) and an estimate of ke, the fraction of the dose eliminated per unit time, of 0.10 hr-1 (95 % CL = -0.01, 0.21). Analysis of urinary elimination rates also yielded ke = 0.10 hr-1 (95% CL = 0.01, 0.18). At necropsy the gastrointestinal tract of each cat was normal.

Iodine resorption and excretion in Betaisodona (Betadine) treatment of extensive burns

Iodine resorption and excretion, glomerular filtration and blood gas ratings in three patients with extensive burns during Betaisodona (Betadine) treatment were examined. The serum-iodine level increased up to 7 mg% as did the urine iodine content. The creatinine in the urine increased up to 100% but serum levels remained normal as did the pH and blood-gas analyses. No signs of iodine-intoxication or acidosis were found. Careful observation of the iodine-glomerular filtration pH and blood gas parameters is recommended, especially in children when Betaisodona is used in dermal burns.

Iodine absorption from the gastrointestinal tract during hypaque-enema examination.

Iodinated contrast agents administered intravenously or intra-arterially may cause serious reactions in hypersensitive patients. Oral administration of Hypaque (diatrizoate sodium) results in minimal absorption of iodine, but the amount of iodine absorbed with Hypaque-enema studies is unreported. Hypaque-enema examinations were performed in 20 normal, nonsensitive patients and increased serum iodine levels ten to 200 times base-line values, peaking after approximately one hour in patients who had measurements obtained for four hours. Therefore, before Hypague-enema studies, patients must be carefully questioned about their tolerance of iodinated contrast agents, and preparations should be made for possible serious hypersensitivity reactions.