A new chinese restaurant syndrome: the "chinese fondue" carbon monoxide mass intoxication

Bernard-Alex Gaüzère, Yasmina Djardem, Arnaud Bourdé, Philippe Blanc. Service de Réanimation. CHD Félix Guyon, 97405 Saint-Denis, Réunion, France.

Keywords : carbon monoxide, intoxication, chinese fondue.

In this paper, we report a rare and original case of carbon monoxide (CO) mass intoxication. CO is produced in large amounts in industry as well as by gazoline engines, home appliances and the incomplete combustion of wood, natural gas, and tobacco products. It is rapidly absorbed through the lungs and binds to hemoglobin, forming carboxyhemoglobin (COHb), with an affinity 210 times that of oxygen. CO is a toxic gas that interferes with oxygen transport and utilization. It produces its adverse effects by reducing the amount of available oxyhemoglobin, and by displacing the oxygen-hemoglobin dissociation to the left. The net effect is profund tissue hypoxemia (1).

A traditional component of the Réunion island gastronomy, the chinese fondue attracts many people. On the 17 of august 1996, (in the southern hemisphere winter), among about one hundred customers dining in a chinese restaurant, several children and then adults, suddently presented dyspnea, nausea, vomiting, headache, confusion and clumsiness. Neither loss of consciousness nor syncope were noted. The victims (17 children, including an infant, mean age 10 ± 4 years, and 36 adults, including a pregnant woman mean age 41 ± 10 years were sitting around several chinese charcoal-pans cooking a chinese fondue. The atmosphere was confined with closed windows and a non-functionning air conditioning system. The relief team removed the victims from the site of exposure, administered normobaric oxygen (10 l/mn), and evacuated them to the nearby hospital. Out of 53 subjects, 2 refused to undergo further medical attention and left the hospital, having received oxygen and before any blood samples were taken.

After 60-90 min intensive oxygenation during transportation to the hospital, the average level of COHb measured in patients, was as follows (38 results only could be traced by the time of the study) :one case, 12% ; (47-year- old female) ;eight cases, 10% ( 6 year-old- male, 11 year-old-female ; 12 year-old-female ; 12 year-old-male ; 35 year-old-female ; 39 year-old-female ; 45 year-old- male and 61 year-old female) ; one case, 7,4% ; seven cases, 4.8% ; and 21 cases, 2% or less

The CO intoxication was confirmed by the carboxyhemoglobin dosages, bearing in mind that the CO half-life decreases to 40-80 min when breathing 100% oxygen.

As symptoms resolved with oxygen, there was no indication of hyperbaric oxygen therapy (2, 3). Nevertheless, the infant and the pregnant woman required treatment for several more hours, because fetal hemoglobin has high affinity for carbon monoxide. Twenty-one victims were hospitalised for 12 to 24 h. All fully recovered.

The clinical manifestations, although mild, the combustion of charcoal in a confined athmosphere, and the moderately elevated levels of COHb after intensive oxygenation, confirm the CO intoxication. The CO intoxication is a rather rare event in a tropical environment in witch the mildness of the winter allows open air. It is the first case of CO intoxication ever reported in our hospital. Moreover, the « chinese fondue » is an original prime cause for CO intoxication.

References

1 Mofenson HC, Caraccio TR, Brody GM. Carbon monoxide poisoning. Am J Emerg Med 2 (3):254-61, 1984

2 Coric V, Oren DA, Wolkenberg FA, Kravitz RE. Carbon monoxide poisoning and treatment with hyperbaric oxygen in the subacute phase. J Neurol Neurosurg Psychiatry 65 (2):245-7 1998

3 Norkool DM, Kirkpatrick JN. Treatment of acute monoxide poisoning with hyperbaric oxygen : a review of 115 cases. Ann Emerg Med 14(12) :1168-71 1985