[A rare cause of cyanosis: Sulphaemoglobinaemia related to thiocolchicoside (Miorel)]. / Une cause rare de cyanose: sulfhémoglobinémie imputable au thiocolchicoside (Miorel).

INTRODUCTION: An acquired abnormality of haemoglobin is among the many causes of cyanosis, especially in patients with no identified cardiorespiratory cause. CASE REPORT: A 50-year-old woman, suffering from amyotrophic lateral sclerosis, was hospitalised for dyspnoea. Physical examination revealed cyanosis that persisted despite oxygen therapy. Discordance between the reduced arterial oxygen saturation and normal arterial oxygen tension led to a search for a dyshaemoglobinaemia as a possible cause. Use of co-oxymetry with spectrophotometry revealed sulphaemoglobinaemia. Sulphaemoglobinaemia is due to irreversible incorporation of a thiol radical into the porphyrin ring of a haem group. This decreases the affinity of haemoglobin for oxygen and thus reduces oxygen carrying capacity. A drug-induced cause is often identified. However, no previously described cause for sulphaemoglobinaemia was identified in our patient. The patient was currently being treated with thiocolchicoside (Miorel((R))). Thiocolchicoside was suspected as the cause because its chemical structure contains an easily hydrolysable thiol radical. Withdrawal of thiocolchicoside led to regression of the sulphaemoglobinaemia. CONCLUSIONS: This report underlines the importance of searching for an acquired abnormality of haemoglobin (methaemoglobinaemia or sulphaemoglobinaemia) in patients with cyanosis resistant to oxygen, in the absence of any cardiorespiratory abnormality. This case is the first to suspect thiocolchicoside as a possible cause of sulphaemoglobinaemia.

Acrocyanosis from phenazopyridine-induced sulfhemoglobinemia mistaken for Raynaud phenomenon.

Rheumatologists are often asked to evaluate patients with Raynaud phenomenon. Occasionally, an alternate explanation is revealed such as acrocyanosis. Methemoglobinemia and sulfhemoglobinemia are rare causes of cyanosis that can be medication-induced. Both are known complications of therapy with phenazopyridine. We report an unusual case of a 45-year-old woman in whom sulfhemoglobinemia from chronic therapy with phenazopyridine was misdiagnosed as due to Raynaud phenomenon and limited scleroderma. This case illustrates the importance of taking into account medication-related adverse events when evaluating patients with Raynaud-like phenomenon.

Identification of sulfhemoglobinemia after surgical polypectomy.

Sulfhemoglobinemia (SHb) is an uncommon cause of cyanosis that is predominantly drug-induced in adults. We report an unusual case of sodium sulfate-induced sulfhemoglobinemia in a 61-year-old woman after surgical polypectomy. Fractional hemoglobin derivates were assayed by spectrophotometry and high-performance liquid chromatography. The SHb ratio was 8.6% in the first sample and 3.77% a month later measured by spectrophotometry. In the blood hemolysate, a new peak was identified as SHb with high-performance liquid chromatography (HPLC). HPLC showed the presence of 9.37% SHb in the first sample and 4.88% a month later. After removing the suspected toxic agent the cyanosis decreased significantly. The findings underline the importance of routine SHb detection in cyanosis of unknown origin especially in emergency cases.

Phenazopyridine-induced sulfhemoglobinemia.

OBJECTIVE: To report a case of sulfhemoglobinemia in a patient receiving phenazopyridine for a urinary tract infection. CASE SUMMARY: A 63-year-old white woman presented to the emergency department with complaints of fatigue and bluish discoloration of her body that had gradually progressed over the previous 6-8 weeks. About 4 months prior to presenting to the emergency department, she had started taking phenazopyridine, an over-the-counter medication for symptoms of dysuria. Because the cyanosis did not improve after the patient received oxygen and methylene blue, sulfhemoglobinemia was suspected and confirmed by spectrophotometer analysis. DISCUSSION: Sulfhemoglobin is a green-pigmented molecule containing a sulfur atom in one or more of the porphyrin rings. It is a rare cause of cyanosis, which is usually drug induced. Sulfhemoglobinemia is suspected when a cyanotic patient has normal to near-normal oxygen tension, laboratory reports of elevated methemoglobin, and does not respond to methylene blue therapy. Sulfhemoglobinemia is relatively rare, despite the widespread use of drugs that have been reported to cause it. Predisposing factors, such as chronic constipation, present in our patient, have been suggested as a source of hydrogen sulfide. CONCLUSIONS: This case of sulfhemoglobinemia, which occurred after the patient took phenazopyridine, is considered a probable adverse event according to the Naranjo probability scale.

[Fatal calcium polysulfide overdose presenting corrosive chemical injury of esophagus and sulf-hemoglobinemia].

A-79-year-old woman ingested a cup of unknown violet agricultural solution intentionally. She was vomiting and smelt of sulfur. Arterial blood gas showed metabolic acidosis and marked cyanosis regardless of relatively high PaO2, caused by sulfhemoglobinemia. A nasogastric tube could not be inserted because of marked stenosis caused by endoscopically proven severe corrosive chemical injury (burn) of esophagus. Considering the smell and the clinical presentation, we concluded that the causative agent was calcium polysulfide or lime-sulphur solution, a common agricultural product used as a fungicide. Despite supportive therapy including infusion of NaNO2, the patient expired 4.5 hours after ingestion. Calcium polysulfide ingestions cause direct injury to the upper gastrointestinal tract, and react with gastric HCl producing poisonous H2S gas, which interferes cytochrome oxidase activity, developing tissue hypoxia, shock, and metabolic acidosis. Sulfhemoglobin is also produced causing severe cyanosis.

An adolescent case of sulfhemoglobinemia associated with high-dose metoclopramide and N-acetylcysteine.

We describe the case of an adolescent girl who received high-dose metoclopramide in combination with oral N-acetylcysteine therapy for acute acetaminophen toxicity. Whole blood-sample analysis for abnormal hemoglobin pigments established the diagnosis of sulfhemoglobinemia. Metoclopramide has been shown to cause sulfhemoglobinemia, particularly when used in repeated high doses. Although N-acetylcysteine alone has not been associated as the cause, we suggest that sulfhemoglobine-mia is a potential complication in patients treated with metoclopramide for the nausea that often accompanies oral N-acetylcysteine therapy for acetaminophen toxicity. Cyanosis without respiratory distress should suggest this diagnosis.

Pseudomethemoglobinemia: a case report and review of sulfhemoglobinemia.

OBJECTIVES: To see if methemoglobin could potentially be misdiagnosed and the limitation of present cooximeters. PATIENT: A 17-year-old girl who overingested a combination of cimetidine, acetaminophen, ibuprofen, and naproxen in a suicide attempt. METHOD: Use of pulse co-oximeters to aid in the diagnosis of suspected sulfhemoglobinemia. RESULTS: Diagnosis of sulfhemoglobinemia achieved with final confirmation made with gas chromatography. Patient steadily improved with supportive care. CONCLUSIONS: There is a potential for the diagnosis of methemoglobin with some of the limitations of present co-oximeters. The laboratory diagnosis of sulfhemoglobinemia can be difficult to make.

Sulfhemoglobinemia after dermal application of DMSO.

A 43-y-old Caucasian female applied 4 ounces of dimethyl sulfoxide (DMSO) to her lower abdomen for treatment of interstitial cystitis. Within 24 h she developed fatigue, cyanosis and dyspnea with mild exertion. She sought medical attention 10 d later, at which time initial laboratory tests revealed a methemoglobin level of 47%. Two doses of 1 mg methylene blue/kg i.v. were given without significant improvement in either her cyanosis or methemoglobin level. Repeat analysis the day following admission using an outside lab demonstrated a sulfhemoglobin level of 6.2% and a methemoglobin level of < 0.1%. No prior reports have associated sulfhemoglobin formation with DMSO application. Carbon monoxide-oximetry may falsely identify sulfhemoglobin as methemoglobin; sulfhemoglobinemia should be considered in cases of methemoglobinemia refractory to methylene blue therapy.

Flutamide-induced cyanosis refractory to methylene blue therapy.

Flutamide, an anti-androgen used in prostate cancer therapy, is also a derivative of aniline. Mild, usually asymptomatic, methaemoglobinaemia has been reported. We report a patient receiving flutamide therapy who developed cyanosis, dyspnoea and anaemia, initially attributed to marked methaemoglobinaemia by the CO-Oximeter method. An unsuccessful trial of methylene blue therapy led to the finding of marked sulphaemoglobinaemia. Sulphaemoglobinaemia has not previously been reported with flutamide use. Recognition of this association is important, given the refractoriness of sulphaemoglobinaemia to methylene blue therapy.

Metoclopramide-induced sulfhemoglobinemia.

Metoclopramide, a drug with oxidant activity, has infrequently been reported to cause methemoglobinemia in infants. We present a unique case in which a patient on chronic metoclopramide therapy developed sulfhemoglobinemia that resolved with subsequent discontinuation of the drug. Mechanisms that may be important in the formation of sulfhemoglobin also are discussed.

Topical anesthetic-induced methemoglobinemia and sulfhemoglobinemia in macaques: a comparison of benzocaine and lidocaine.

Benzocaine (BNZ) and lidocaine (LC) are commonly used topical (spray) anesthetics approved for use in humans. Benzocaine has structural similarities to methemoglobin (MHb)-forming drugs that are current candidates for cyanide prophylaxis, while LC has been reported to increase MHb in man. In this study, we compared MHb and sulfhemoglobin (SHb) production in three groups of Macaques (Chinese rhesus and Indian rhesus (Macaca mulatta) and pig-tailed macaques (Macaca nemestrina)) after exposure to BNZ and LC. Formation of SHb, unlike MHb, is not thought to be reversible and therefore is considered to be of greater toxic significance. Both MHb and SHb levels were measured periodically on a CO-Oximeter. All rhesus macaques (n = 8) were administered an intratracheal/intranasal) dose of 56 mg (low dose) or 280 mg (high dose) of BNZ or 40 mg of LC in a randomized cross-over design (all animals received all three treatments). Pig-tailed macaques (n = 6) were given an intranasal dose of 56 mg of BNZ and 40 mg of LC. As no differences in the peak MHb or time to peak (mean +/- SD) were observed among the three macaque subspecies, the data were pooled. Lidocaine did not cause MHb or SHb formation above baseline in any monkey. In contrast, all monkeys (n = 14) had a significant elevation in peak MHb formation after 56 mg of BNZ, which ranged from 4.0% to 19.4% with an average of 8.6 +/- 4.0% (mean +/- SD), with peak MHb levels reached at 30 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Discomforts and laboratory findings in workers exposed to sulfur dioxide.

In a broom manufacturing factory the authors performed microclimatic measurements, measurements of sulfur dioxide concentration and dust content. Workers (n = 190) were polled regarding discomforts characteristic of sulfur dioxide effects. Sulfates were determined in urine of 56 subjects, and methemoglobin and sulfhemoglobin were determined in blood. Sulfates were determined in 43 controls and methemoglobin and sulfhemoglobin were determined in 39 controls. Sulfur dioxide concentration in work environment ranged from 17.1 to 149.4 mg/m3 in winter and from 0 to 0.75 mg/m3 in summer. The exposed workers complained most often of coughing (94.2%), dyspnea (91.0%), burning in nose, eyes and throat (from 74.7 to 83.7%), substernal pain (75.3%), sore throat (74.7%), tearing (64.7%), etc. Sulfate concentrations were found to be statistically significantly higher (P less than 0.01) in urine of workers exposed to sulfur dioxide than in the controls. Methemoglobin concentrations were also significantly higher in blood of the exposed workers, whereas no difference was found in concentrations of sulfhemoglobin.

Oxygen toxicity and hemoglobinemia in subjects from a highly polluted town.

Red blood cell activities of superoxide dismutase and glutathione peroxidase, two key enzymes responsible for the control of the concentrations of activated oxygen species, were approximately two-fold higher in residents of Vila Parisi (Cubatão, Brazil)--a higher polluted neighborhood--than in a population sample from São Paulo City. The catalase levels were the same in both samples. A concurrent high concentration of methemoglobinemia and sulfhemoglobinemia was encountered in the blood of Vila Parisi residents. These data raise the possibility that the increased rate of oxyhemoglobin oxidation yielding O-.2 and H2O2 may be relevant to mutagenesis induced by HO. radicals.