A. C. Williamson has suggested that acidotic shock is the cause of sudden death from anesthesia at the end of labor. This would seem to be a logical explanation of the five anesthetic deaths that have occurred in our 15,000 deliveries during the past six years. We have shown that each of these cases had prolonged labor. When labor is prolonged, the acidosis increases hour by hour and with the lowering of the CO2 there is a coincident lowering of the blood pressure. Since we have been working on this theory, we feel that all patients who show signs of acidosis should be treated for this condition before operation is attempted.There are two or three clinical signs that are of aid in diagnosing acidosis. The patients have bright red lips, the body surface is dry, and the blood pressure low and exhaustion marked.In the one case in which we carried on the CO2 readings and blood pressure observations, the blood pressure did not drop in relation to the CO2 percentage as cited by Cannon in his traumatic shock cases. These CO2 readings, however, were not obtained immediately but held over until morning and perhaps, therefore, cannot be considered as accurate. Some obstetrician who has the facilities at hand should conduct a research controlling the CO2 and the blood pressure readings at six-hour intervals in labors that are from thirty to sixty hours in length. This would give us definite information as to whether the blood pressure readings might be accepted as an indication of the actual stage of acidotic shock.Morphine is one of the first requirements for relieving the condition of acidosis. The rest afforded by ¼ gr., in itself, tends to raise the CO2 combining power and relieves the nervous tension of the patient. Morphine should not be used in long labors for the purpose of allowing the patient to rest and then return to a stronger labor but to prepare her for operative delivery. If the labor is over twelve hours, the patient should have regular feedings of high caloric and easily assimilable food such as milk sugar with lemon or orangeade. If the labor endures for more than twenty-four hours and cannot be brought to a close because of obstetric contraindications, sugar should be given by vein. When the blood pressure is below 85, operative intervention must be postponed until it has been brought to 100 or above. This may be accomplished by the administration of 350 c.c. of gum glucose injected by vein, at a rate not greater than 4 c.c. per minute and at a temperature of 104°. When the blood pressure has been raised to 100, operation may be started.Of all the forms of delayed labor, the one most difficult to treat is the so-called primary inertia and rigid cervix. It is commonly thought that the Beck type of cesarean section is the answer to this problem, but the loss of immunity from increased exhaustion and acidosis and the entrance of infection through rupture of the membranes and repeated vaginal examinations, are contraindications. Probably the better procedure is to insert a No. 4 bag and pack the vagina with wet gauze, delivering the patient by forceps operation when dilatation has occurred.The obstetrician must be called to account for that proportion of the maternal deaths due to the conduct of labor. Blood pressure readings and, where possible, checking of the CO2, will confirm our clinical diagnosis of acidosis and no anesthesia should be given and no operation should be performed until the blood pressure is 100 or over. This will lead to a diminution of the sudden and obscure deaths that occur at the end of long labors.