LAUSR

We read the correspondence with great interest and would like to thank you for your knowledgeable comments. Our study includes the comparison of high-flow nasal cannula (HFNC) oxygen therapy and non-rebreather face mask (NRFM) in the emergency department treatment of carbon monoxide poisoning, which is an important cause of poisoning in our country. During the study period, there was no ongoing pandemic. Therefore, HFNC oxygen devices were used in the treatment of poisoning patients. We agree that many hospitals are forced to utilize their respiratory support devices for treatment of complications related to current pandemic. In these unfortunate scenarios, patients with higher potential to benefit from HFNC can be given higher priority based on the relatively short (5.8min) difference of half-life in our treatment groups. However, some advanced hospitals and tertiary care centers have HFNC oxygen devices already set-up near bedsides of emergency departments and intensive care units, with trained personal which frequents their use. We think it may be wiser to prefer HFNC oxygen devices in these suitable conditions. In our country, HFNC oxygen therapy a new oxygen delivery system. For this reason, we were able to get the ethics approval from ethics committee only for retrospectively according to this historical distinction for this study. Unfortunately, since it was a retrospective study, it was not possible to make a clear assessment of patient comfort and recovery time of symptoms. However, it is known that humidification and warming of the gas delivered to the patient in HFNC oxygen therapy improves patient comfort as well as improves mucociliary function, supports secretion excretion, reduces airway contractions and most importantly, reduces respiratory workload. In addition, it can be said that the nasal cannula that allows the person to talk, eat and drink water is more comfortable than NRFM which covers the face [1]. We want to thank the author for drawing attention to the regional variety of demographic features and primary causes of CO poisoning. Epidemiology and surveillance data greatly differs across the globe; for example patients in some middle-eastern countries such as Iran are primarily women [2], while in Denmark men are the most affected group due to causes such as defective heat sources, indoor charcoal burning and fires [3]. According to recently updated information obtained from Global Data Exchange registry, incidence of CO poisoning does not differ between sexes worldwide [4]. While half-life difference of the COHb between different treatment modalities explained in our study is not related to the source (heating stove, gas-fired combi boiler, or barbeque) of CO inhaled, gender difference may possibly play a part in elimination of the COHb due to physiological differences as presented in our study [5]. In CO poisoning, the source (heating stove, gas-fired combi boiler, or barbeque) of the poisoning does not change the half-life of COHb. Therefore, we think that etiologic reasons do not prevent the generalization of the study results to the other populations. Carbon monoxide (CO) poisoning is still a common cause of emergency department (ED) visits worldwide. The issue you highlighted in the last paragraph is very important; education of the target population in terms of preventive measures is important to prevent carbon monoxide poisoning.