S2k guideline diagnosis and treatment of carbon monoxide poisoning.

Carbon monoxide (CO) can occur in numerous situations and ambient conditions, such as fire smoke, indoor fireplaces, silos containing large quantities of wood pellets, engine exhaust fumes, and when using hookahs. Symptoms of CO poisoning are nonspecific and can range from dizziness, headache, and angina pectoris to unconsciousness and death. This guideline presents the current state of knowledge and national recommendations on the diagnosis and treatment of patients with CO poisoning. The diagnosis of CO poisoning is based on clinical symptoms and proven or probable exposure to CO. Negative carboxyhemoglobin (COHb) levels should not rule out CO poisoning if the history and symptoms are consistent with this phenomenon. Reduced oxygen-carrying capacity, impairment of the cellular respiratory chain, and immunomodulatory processes may result in myocardial and central nervous tissue damage even after a reduction in COHb. If CO poisoning is suspected, 100% oxygen breathing should be immediately initiated in the prehospital setting. Clinical symptoms do not correlate with COHb elimination from the blood; therefore, COHb monitoring alone is unsuitable for treatment management. Especially in the absence of improvement despite treatment, a reevaluation for other possible differential diagnoses ought to be performed. Evidence regarding the benefit of hyperbaric oxygen therapy (HBOT) is scant and the subject of controversy due to the heterogeneity of studies. If required, HBOT should be initiated within 6 h. All patients with CO poisoning should be informed about the risk of delayed neurological sequelae (DNS).

How delay to recompression influences treatment and outcome in recreational divers with mild to moderate neurological decompression sickness in a remote setting.

INTRODUCTION: This retrospective review examined the influence of delay to recompression on mild/moderate neurological decompression sickness (DCS) in divers, as a pilot for an abandoned prospective study. METHODS: The medical histories of 28 divers treated at a hyperbaric facility in the Maldive Islands in the Indian Ocean were evaluated. The term 'oxygen unit' (OU; 1 OU = 1 bar (ambient pressure) x 1 min x 1.0 (inspiratory oxygen fraction)) was used to enable a quantification of administered hyperbaric oxygen. Visual analog symptom scale (VASS) scores of the worst symptom at presentation (used routinely at the clinic to quantify treatment response) were analysed. RESULTS: Divers presenting later than 17 hours after surfacing (the median time to treatment after surfacing for the whole group) were likely to have more intense symptoms on VASS (median 100%) than those who presented earlier for treatment (median 30%, P = 0.02). Total OU needed to treat divers presenting within 17 hours did not differ from those treated later (P = 0.11). Divers with ≥ 70% symptom reduction with the first hyperbaric oxygen treatment (HBOT) needed between 260 and 1,463 OU in total, whereas those with less than 70% reduction in VASS needed between 263 and 2,126 OU (P = 0.04). CONCLUSIONS: Neither more HBOT nor a worse outcome of DCS could be related to delay to treatment longer than 17 hours. The amount of oxygen that had to be administered in total during the whole HBOT course was lower in cases that responded better to the initial HBOT.