Our CRNA had a patient that was in cardiac arrest and the CRNA was unable to intubate the patient. She did attempt and gave the patient a IM injection of a Succ and continued to bag the patient. Her time with the patient was 45 minutes. Would it be incorrect to bill for the intubation with a modifier 53? The CRNA is asking me about billing for CPR. I will admit I am not an expert on anesthesia coding so any help would be great.