Use of Hydroxocobalamin (Vitamin B12a) in Patients With Vasopressor Refractory Hypotension After Cardiopulmonary Bypass: A Case Series.

Hydroxocobalamin (vitamin B12a) is an emerging treatment for vasoplegic syndrome (VS) associated with cardiopulmonary bypass (CPB). Given its cost and scarcity, an institutional guideline for its use as a rescue treatment in cases of suspected VS was developed. Hemodynamic variables and vasopressor requirements were reviewed for a series of 24 post-CPB patients who received B12a. Favorable changes in hemodynamic parameters and vasopressor requirements were seen after B12a administration although guideline criteria for VS were inconsistently met. These findings support the continued study of B12a in patients with CPB-associated VS.

Signs and symptoms after temporomandibular joint washing and cannula placement assessed by cone beam computerized tomography.

OBJECTIVE: Analyses of temporomandibular joint synovial fluid using the hydroxocobalamin push-pull technique are increasingly used. However, objective complications and subjective experiences from this procedure have not been described. Firstly, this study aimed to describe discomfort and potential side-effects of this method with special emphasis on symptoms related to the arthrocentesis to be used for future patient information and Ethical Committee applications. Secondly, this study aimed to evaluate the use of cone beam computed tomography (CBCT) as control of intra-capsular cannula placement. METHODS: Twenty healthy, young adult volunteers were included. Extensive objective and subjective questionnaires were completed before and 14 days after the synovial fluid sampling. With the cannula inside the joints a CBCT was done to investigate if this procedure can be used to verify intra-capsular cannula position. RESULTS: The subjective findings: Most subjects did experience mild pain or discomfort post-operatively. In 12 of 20 subjects symptoms had resolved after 2 days and no subjects had symptoms for more than a week. The longer lasting symptoms were mainly transient joint sounds on mandibular movement. Objective findings: 14 days after the sampling mandibular protrusion had improved 1 mm, but all other objective measures were equal compared to baseline. CBCT showed a large variation in cannula position and no conclusions could be drawn from this. CONCLUSION: The hydroxocobalamin push-pull synovial fluid sampling may cause minor, transient symptoms. CBCT does not seem to provide any clinical benefits concerning the correct cannula position in relation to the upper joint compartment and disc.

Pseudo-blood leak? A hemodialysis mystery.

Hydroxocobalamin is a treatment for cyanide toxicity with few side effects. We report a case of a hemodialysis patient whose treatment was compromised by hydroxocobalamin interference with the blood leak detector.

Type I immediate hypersensitivity reaction to cyanocobalamin but not hydroxycobalamin.

We report a case of a 42-year-old woman with a background of autoimmune polyglandular syndrome, who developed a type I immediate hypersensitivity reaction to intramuscular cyanocobalamin. Intradermal testing showed a positive reaction to cyanocobalamin. The patient was subsequently treated with intramuscular hydroxycobalamin after negative intradermal testing to this alternative B(12) compound. A review of previously described cases of hypersensitivity to either compound provides a rationale for the management of this rare but serious side-effect.

Acquired methemoglobinemia after hydroxocobalamin administration in a patient with burns and inhalation injury.

CONTEXT: Hydroxocobalamin is an effective cyanide antidote. While erythema, hypertension, and chromaturia are recognized side effects, methemoglobinemia has not been reported. Methemoglobin levels are most accurately measured by co-oximetry. We describe an extensively burned patient who developed methemoglobinemia within an hour of hydroxocobalamin administration. CASE DETAILS: A 47-year old man without genetic deficiencies or abnormal hemoglobin variants presented with 61% body surface area thermal burns and grade 1 inhalation injury sustained during a tugboat engine explosion. On admission, lactate was 9.24 mmol/L, methemoglobin 1%, and carboxyhemoglobin 0.2% by blood gas analysis with co-oximetry. Despite large-volume resuscitation, lactate remained elevated (7-8 mmol/L). Intravenous hydroxocobalamin (5 g) was administered at postburn hour 19 for possible cyanide toxicity. Immediately thereafter, he became hypertensive with reflex bradycardia. Lactate decreased to 5.51 mmol/L, methemoglobin rose to 4.10%, and oxygen saturation by pulse oximetry decreased to 74-80% (despite arterial oxygen saturation of 95% by cooximetry). Methemoglobin concentration peaked at 13.40% at postburn hour 33. Methylene blue was not administered. CONCLUSIONS: Methemoglobinemia in our patient was temporally associated with hydroxocobalamin administration.

Prospective study of hydroxocobalamin for acute cyanide poisoning in smoke inhalation.

STUDY OBJECTIVE: To assess outcomes in patients treated with hydroxocobalamin at the fire scene or in the ICU for suspected smoke inhalation-associated cyanide poisoning. METHODS: Adult smoke inhalation victims with suspected cyanide poisoning as determined by soot in the face, mouth, or nose or expectorations and neurologic impairment received an intravenous infusion of hydroxocobalamin 5 g (maximum 15 g) at the fire scene or in the ICU in this observational case series conducted from 1987 to 1994. Blood cyanide specimens were collected before administration of hydroxocobalamin. The threshold for cyanide toxicity was predefined as greater than or equal to 39 micromol/L. RESULTS: The sample included 69 patients (mean age 49.6 years; 33 men), of whom 39 were comatose. Out-of-hospital deaths were excluded. Fifty of the 69 patients (72%) admitted to the ICU survived after administration of hydroxocobalamin. In the group in which cyanide poisoning was confirmed a posteriori (n=42), 67% (28/42) survived after administration of hydroxocobalamin. The most common adverse events were chromaturia (n=6), pink or red skin discoloration (n=4), hypertension (n=3), erythema (n=2), and increased blood pressure (n=2). No serious adverse events were attributed to hydroxocobalamin. Laboratory tests revealed transient alterations in renal and hepatic function consistent with the critical condition of the patients and mild anemia consistent with progressive hemodilution. CONCLUSION: Empiric administration of hydroxocobalamin was associated with survival among 67% of patients confirmed a posteriori to have had cyanide poisoning. Hydroxocobalamin was well tolerated irrespective of the presence of cyanide poisoning. Hydroxocobalamin appears to be safe for the out-of-hospital treatment of presumptive cyanide poisoning from smoke inhalation.