Sodium bicarbonate has been established for long time as the first choice on the treatment of metabolic acidosis. Meanwhile, Cohen and Woods classified lactic acidosis which plays a major role of metabolic acidosis into type A, accompanied by hypoxia, and type B1, B2 & B3, without hypoxia. It has been well known that sodium bicarbonate aggravate type B group lactic acidosis. Recently, Arieff and others insisted that the onset of type B was initiated by hypotension with hypoxia. Graf and others verified type A always accompanied with type Bs. Sodium bicarbonate does alkalize extracellularly only and increase hydogen content intracellulary by diffusion of carbon dioxide into cells. Hyperosmolarity induced by its administration caused release of hydrogen from erythrocytes as well as decreased P50 value. Hepatic cellular acidosis followed by sodium bicarbonate administration gave rise to lactate acidosis in vicious cycle. It should be notified that sodium l-lactate should never cause elevation of lactate levels in blood. There is competitive uptake by cellular menbrane between d-lactate and l-type. On racemic sodium lactate in Hartmann's solution, however, 30% of d-sodium lactate will be not metabolized to bicarbonate. Graf suggested use of dichloroaccetate for type A lactic acidosis, while author's experiment on its use was unsatisfied. Use of THAM could be reconsidered, however, its disadvantages has been reported by many. Redox potentials in the cytosol could be improved by either use of THAM or DCA as well as methylene blue, but they were not good for redox state in the mitochondria. Author afraid of over-production of β OH-butylate from acetoacetate by their use in mitochondria. So far, besides a grave of branched chain aminoacids, sodium bicarbonate has still superiority on any alkalizing agents. As Ryder notified, low dose long time infusion of sodium bicarbonate aimed to attain the minimum levels of arterial PH 7.20 and 10mE/L of HCO3 content, should be recommeneded. On the same time, lactate clearance by the liver should be supported by increased portal blood flow by infusion of dopamin as well as enriched oxygen delivery.
This prospective study was designed to survey the incidence, prevention and treatment of massive atelectasis in 1222 consecutive patients following upper abdominal surgery. The massive atelectasis was assessed by radiologically. Following perioperative examinations were undertaken: 1. Pulmonary function test except emergency case. 2. Preoperative upright and supine chest x-ray. Supine chest x-ray was taken before extubation and at 24, 48, 72 and every day or every two days thereafter unless required frequently. 3. Blood gases were analysed preoperative, operative and postoperative period when indicated. 4. Frequent and close auscultation of the chest. Preventive measures were as follows: 1. Preoperative deep breathing exercise by tissue paper breathing method and coughing exercise. 2. Coughing and selective bronchial suctioning using a curved tipped catheter with a guide mark during operation and before extubation. 3. Encouraging deep breathing by tissue paper breathing method and coughing postoperatively. We did not use IPPB nor incentive spirometer. The chest x-ray was taken and blood gases were analysed when the breath sound did not improved by above mentioned measures (2 and 3) or when indicated. Following treatments were performed. 1. Vigorous tracheal compression. 2. Transtracheal injection. 3. Selective bronchial suctioning following endotracheal intubation, when the breath sound did not improved by 1 and 2 procedures or atelectasis was assessed by the chest x-ray. Results: No atelectasis was found at the end of operation. Five atelectasis occurred in 5 out of 1222 patients. Two cases of atelectasis occurred among 81 cases of emergency. One case was treated by vigorous external tracheal compression and another one case was treated by transtracheal injection. The rest of three cases was treated by selective bronchial suctioning following endotracheal intubation. We did not use bronchofiber scope in this study. We found that important preventive measures were frequent and close auscultation of the chest, coughing and selective bronchial suctioning during operation and bofore extubation. In the postoperative period, encouraging deep breathing and coughing were also important measures of prevention. The important procedures of treatment were external tracheal compression, transtracheal injection and selective bronchial suctioning following intubation. The proper techniques of selective bronchial suctioning was described.