This article reports a rare and lethal case of cyanide poisoning, aiming to explore its early diagnosis and successful treatment strategies. Upon admission, the patient presented with cardiac and respiratory arrest, deep coma, and severe metabolic acidosis. The core resuscitation measures included early mechanical ventilation, vasoactive drug support, bicarbonate therapy, and the early initiation of continuous blood purification as part of a multimodal strategy. We observed that a combination of elevated central venous partial pressure of carbon dioxide (PvCO2) and elevated lactate provided potential bedside clues for early suspicion of cyanide poisoning. During treatment, a rise in PvCO2 accompanied by a decrease in lactate was noted, which may serve as a hypothesis-generating observation for treatment response, acknowledging the influence of multiple concurrent interventions. The patient recovered substantially after comprehensive treatment. This case provides valuable experience for the treatment of cyanide poisoning.