Methemoglobinemia misdiagnosed as ruptured ectopic pregnancy

Nitrites: An Old Poison or a Current Hazard? Epidemiology of Intoxications Covering the Last 100 Years and Evaluation of Analytical Methods

In recent times, there has been a concerning and noteworthy rise in the global use of sodium nitrite for suicidal purposes. This is facilitated either through the employment of specialized "suicide kits" or by acquiring sodium nitrite through alternative means. Additionally, another occurrence contributing to nitrite poisoning is the recreational utilization of nitrites in the form of volatile aliphatic esters of nitrous acid, commonly referred to as "poppers". Based on current available papers and reports on the subject of nitrates, nitrites, and poppers intoxications, an epidemiological analysis and evaluation of analytical methods were performed. A total of 128 papers, documenting a collective count of 492 intoxication cases, were identified. Additionally, in order to complete the epidemiological profile of nitrite poisoning, the authors briefly examined six cases of nitrite intoxication that were under investigation in our laboratory. Furthermore, a review of nitrite poisoning cases over the past 100 years shows that the old poison is still in use and poses a substantial risk to society.

Anemia That Presented with Desaturation: A Focus on Core Concepts

Background. Methemoglobinemia is a potentially life-threatening condition which presents with cyanosis and characteristic “chocolate-coloured blood.” Although a co-oximetry would give a prompt diagnosis, there have been multiple reports of misdiagnosing this treatable condition—from being diagnosed as sepsis to asthma and even being operated for “ruptured ectopic pregnancy.” Here, we report a case which presented without the classical signs of poisoning and methemoglobinemia—without vomiting, cyanosis, or chocolate-coloured blood. We also discuss the common misconceptions regarding anemia physiology and the pitfalls in diagnosing this condition and warn the reader regarding the reflexive use of antidotes like methylene blue. Case Presentation. A well-grown 3-year old boy presented with an acute history of irritability, cola-coloured urine, and desaturation on examination. The child was pale, with tachypnoea and in failure. Blood smear was suggestive of severe hemolytic anemia. Methemoglobinemia was diagnosed on co-oximetry. By focussing on physiologic principles of management rather than a specific antidote, the child was discharged home, well and active within 3 days of intensive care admission.

A Rare Cause of Methemoglobinemia: How Safe are So-called Biopesticide?

With increasing awareness of "greener" environment, market is flooded with biopesticide. Natural insecticides can be chemical, mineral, or biological. We report an unusual case of methemoglobinemia after deliberate ingestion of an insecticide containing extract of pine oil and azadirachtin oil, Ti oil, and kerosene. On literature search, no such case report has been documented so far. How to cite this article: Gupta P, Verma PK. A Rare Cause of Methemoglobinemia: How Safe are So-called Biopesticide? Indian J Crit Care Med 2020;24(3):208-209.

Rare Case of Methemoglobinemia Complicating Pregnancy

A patient at 38 weeks of gestation when taken for emergency cesarean section had her oxygen saturation of 66 to 70% (by saturation probe on monitor) in operation theatre. She was otherwise asymptomatic but her oxygen saturation was persistently low on the monitors. Her arterial blood gas analysis showed all parameters to be normal. Her electrocardiography was normal. Her surgery was imperative but due to her reduced oxygen saturation she became a high-risk case. In presence of senior consultants of anesthesia and gynecology and under high-risk consent she had an uneventful cesarean delivery. Physician and cardiologist opinions were sought thereafter. The outcomes and the results of our efforts to find the etiology of her reduced saturation on monitors despite being clinically asymptomatic lead to the disclosure of this rare hemoglobinopathy. Mother and baby had uneventful course after delivery and were discharged well.

Custom visible to infrared, multi-wavelength light emitters for pulse oximeter applications

Compact multi-wavelength light sources have been developed to provide flexibility in pulse oximeter device design. Advantages of these light sources include emitting light of multiple wavelengths with a constant ratio of intensity, and a co-linear light propagation path through tissue. These devices can function as normal pulse oximeter to determine oxygen saturation and pulse rate, but this approach potentially reduces circuit complexity, reduces motion artifacts and enables multi-wavelength sensing of different forms of hemoglobin or other blood products.

Anesthetic experience of methemoglobinemia detected during general anesthesia for gastrectomy of advanced gastric cancer -A case report-

Methemoglobinemia is an uncommon but potentially fatal disorder. Most cases have no adverse clinical consequence and require no treatment, but methemoglobinemia is often overlooked as a cause of low oxygen saturation, and often mistaken for the more common causes of hypoxia by anesthesiologists despite simple bedside tests that indicate the presence of this treatable abnormality. We present a 68-year-old female patient who underwent gastrectomy for advanced gastric cancer with bleeding. In the preoperative period, the patient showed cyanosis and oxygen saturation was 85% by pulse oximeter, but oxygen saturation by arterial blood gas analysis was 100%. After tracheal intubation, the methemoglobin level was 18.3%. Ascorbic acid and methylene blue were administered. During preanesthetic evaluation, the patient had not informed the anesthesiologist that she had been taking dapsone.

Pulse-oximetric measurement of prilocaine-induced methemoglobinemia in regional anesthesia

BACKGROUND

The Masimo Radical 7(®) is a new pulse CO oximeter designed to measure methemoglobin. The device has not been evaluated in a clinical setting.

METHODS

In this prospective observational study we compared the arterial methemoglobin levels and the corresponding pulse CO-oximetric values of the Radical 7(®) in regional anesthesia with prilocaine.

RESULTS

We analyzed 360 data pairs with methemoglobin values up to 6.6%. The mean bias and limits (± 1.96 sd) of the device were 0.27% (± 1.33%).

CONCLUSION

We found a high degree of agreement in measurement of methemoglobin between the 2 methods.