Plasma lidocaine levels occurring with endotracheal administration during hemorrhagic shock

During the many emergency situations in which venous access is difficult or impossible, endotracheal drug administration is an effective alternative means of delivering life-saving medications. Shock is a commonly encountered emergency situation in which endotracheal drug therapy can and is often used. Yet whether a drug given endotracheally during shock can be absorbed from the lungs and pass into the bloodstream is not known. Forty-five sets of plasma lidocaine levels drawn at 5, 15, 30 and 60 min after the administration of endotracheal lidocaine at a dose of 2 or 4 mg/kg were obtained in dogs either in shock or in a normal control group: Group I = "Non-shock" or normal control, N = 27; Group II = "Shock", N = 18. Significantly higher plasma lidocaine levels occurred in the shock group in all time periods and with either dose of lidocaine (P less than 0.001). Mean plasma lidocaine levels (micrograms/ml) at 5 min were: (at 2 mg/kg dose) Group I = 1.1, Group II = 2.0; and (at 4 mg/kg dose) Group I = 2.3, and Group II = 5.1. The dose of lidocaine, the technique of administration, and the time at which the plasma lidocaine level was drawn as well as whether shock vs. non-shock was present were all highly significant factors (P less than 0.001) in determining plasma lidocaine levels. In summary: (1) endotracheal lidocaine is absorbed during shock and (2) higher plasma lidocaine levels occur during shock than during the non-shock control state. This suggests that the dosage of endotracheal medication may need to be adjusted for various clinical conditions such as shock.