Interpreting sulfhemoglobin and methemoglobin in patients with cyanosis: An overview of patients with M-hemoglobin variants.

INTRODUCTION: Methemoglobin (MetHb) and sulfhemoglobin (SHb) measurements are useful in the evaluation of cyanosis. When one or both values are elevated, additional analysis is important to establish the etiology of the disorder. Methemoglobinemia occurs from acquired or hereditary causes with diverse treatment considerations, while true sulfhemoglobinemia is only acquired and treatment is restricted to toxin removal. Some toxic exposures can result in a dual increase in MetHb and SHb. Hereditary conditions, such as M-Hemoglobin variants (M-Hbs), can result in increased MetHb and/or SHb values but are clinically compensated and do not require treatment if they are cyanotic but otherwise clinically well. METHODS: Herein, we report 53 hemoglobin variant cases that have associated MetHb and SHb levels measured by an adapted Evelyn-Malloy laboratory assay method. RESULTS: Our data indicate M-Hbs cause variable patterns of MetHb and SHb elevation in a fairly reproducible pattern for the particular variant. In particular, α globin chain M-Hbs can mimic acquired sulfhemoglobinemia due to an isolated increased SHb value. CONCLUSION: If the patient appears clinically well other than cyanosis, M-Hbs should be considered early in the evaluation process to differentiate from acquired conditions to avoid unnecessary testing and treatment regimens and prompt genetic counseling.

[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.

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.

[Measurement of sulfhemoglobin (S-Hb) blood levels to determine individual hydrogen sulfide exposure in thermal baths in Italy]. / La concentrazione di solfo-emoglobina presente nel sangue è una misura affidabile dell'esposizione individuale a vapori solfurei: il caso degli stabilimenti idrotermali in Italia.

Significant exposure to hydrogen sulfide may occur in workers at sulphureous thermal baths. Work-related exposure to hydrogen sulfide may be shown by measuring sulfhemoglobin (S-Hb) blood levels. In this study we measured S-Hb blood levels in two groups of workers at two different thermal baths and compared these with hydrogen sulfide concentrations in the air of the two work environments. Our results show that blood S-Hb levels can be considered a reliable measure of individual exposure to hydrogen sulfide.

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.

A case of sulfhemoglobinemia and emergency measurement of sulfhemoglobin with an OSM3 CO-oximeter.

We describe a case of sulfhemoglobinemia associated with toxic paint ingestion. Blood gases, oxygen content, and fractional hemoglobin derivatives were assayed with Radiometer 520 and OSM3 instruments. Although the CO-oximeters indicated the presence of sulfhemoglobin (SulfHb), the results were not quantitative. An OSM3 service software program was activated to obtain the actual concentrations of the hemoglobin fractions. Subsequently, we evaluated the performance of the OSM3 service program for the analysis of SulfHb by performing precision studies and comparing OSM3 results with those of an AVL 912 CO-oximeter. Retrospectively, we determined that the patient's specimens contained 6% SulfHb. There was an obvious deviation between standard OSM3 oxyhemoglobin fraction measurements and those obtained by using its service program-the effect of a high SulfHb content.

Oxidative stress and antioxidative status of plasma and erythrocytes in patients with vivax malaria.

OBJECTIVES: To investigate the oxidative stress and antioxidative status of plasma and erythrocytes in patients with vivax malaria and healthy persons. DESIGN AND METHODS: Activities of antioxidative enzymes, rates of pathways of hexose monophosphate shunt and purine salvage, levels of lipid peroxidation, reduced glutathione, methemoglobin and sulfhemoglobin of erythrocytes were determined. Lipid peroxidation and levels of antioxidant substances were measured. RESULTS: Antioxidants levels and antioxidative enzymes activities were lower and lipid peroxidation, purine salvage rate were higher in patients group than controls. Erythrocyte glucose-6 phosphate dehydrogenase (G-6-PD) activity was not different from that of healthy subjects. CONCLUSIONS: Oxidative mechanisms were observed to be dominant compared with antioxidative mechanisms in patients with vivax malaria. Therefore, oxidative stress may be produced and maintained by the host defense mechanisms against malarial infection.

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.

Toxic methaemoglobinaemia and sulfhaemoglobinaemia in a population form Cubatão (SP, Brazil): effect of industrial pollution?

Metahemoglobinemia e sulfohemoglobinemia tóxica em uma população de Cubatão (SP, Brasil); efeito da poluição industrial? Foram determinadas as concentrações de metahemoglobina em amostras de sangue de duas populações do Estado de São Paulo, uma com alto nível de poluição industrial (Cubatão-Vila Parisi) e outra sem poluição industrial (São José do Rio Preto). As duas populações diferiram significativamente e isto sugere que a metahemoglobinemia e sulfohemoglobinemia observadas na população de Cubatão são de origem tóxica devido à poluição industrial

[Preoperative care and accumulation of non-active hemoglobin derivatives in blood of patients]. / Predoperatsionnaia podgotovka i nakoplenie neaktivnykh derivatov gemoglobina v krovi bol'nykh.

A study of the concentration of met- and sulfhemoglobine in patients on admission to the clinic and at the end of the preoperative management and treatment was carried out upon 35 surgical cases. The medicamentous therapy included the drugs favouring the restoration of methemoglobin (10.20% and 40% glucose solutions, ascorbic acid etc.). Therewith the concentration of non-active hemoglobine derivatives dropped at the end of the preoperative management and treatment.

[Formation of sulfhemoglobin using various drugs].

It is well known that aniline and hydroxylamine derivatives induce methemoglobinemia in humans as well as various animal species. It was noticed that sulfhemoglobinemia was induced by subchronic administration of N-(4-chlorophenyl)-beta-(4-hydroxymethylphenoxy)ethylurethane (HPU) to rabbits (p.o.), cats (i.p.) and mice (i.p.). Sulfhemoglobin (SHb) and methemoglobin (MHb) formation by various compounds structurally related to HPU were examined by a single and three consecutive intraperitoneal administrations to mice. It was found that by a single administration, methemoglobinemia was induced by phenylhydroxylamine (PHA), nitrobenzene (NB), aniline (A), 2-chloro-A (2-Cl-A), 3-Cl-A, 4-Cl-A, acetanilide (AA), phenacetin (PA), N-(4-chlorophenyl)ethylurethane (CPU), hydroxylamine (HA) and sodium nitrite (SN), and was not observed with phenylurethane, HPU, methylhydroxylamine (MHA), methylamine and nitromethane (NM). On the other hand, with sulfhamoglobinemia which appeared much more delayed than MHb, a single administration, was found to be induced by PHA, 3-Cl-A, 4-Cl-A, PA, CPU, MHA and SN. Furthermore, with three consecutive administrations, such was induced by NB, 2-Cl-A, AA, HPU and NM even though SHb was not demonstrated with a single administration. Structure-SHb forming property relationship and mechanism for SHb formation are discussed.