Effect of Low Dose Norepinephrine Infusion on Myocardial Oxygen Consumption and Lactate Metabolism / 대한마취과학회지

BACKGROUND: Norepinephrine infusion has been reported to be associated with adverse events in ischemic heart disease due to elevation of afterload and cardiac oxygen consumption. During coronary artery bypass graft, we observed changes of hemodynamic and laboratory parameters in low dose norepinephrine infusion. Also, we investigated effects of norepinephrine on cardiac oxygen metabolism by calculating oxygen consumption and lactate extraction ratio. METHODS: Fifteen patients, ASA PS class IV-V, scheduled for elective coronary artery bypass graft were enrolled in this study. All of the operations were performed under general anesthesia. During harvesting of graft vessels, norepinephrine was infused at the rate of 0.02microgram/kg/min, and then at the rate of 0.05microgram/kg/min. We measured various hemodynamic and laboratory parameters in three periods (baseline, NE 0.02microgram/kg/min, NE 0.05microgram/kg/min). Also we calculated oxygen consumption and lactate extraction ratio of myocardium. RESULTS: In the baseline period(no norepinephrine infusion), oxygen consumption (VO2) is 159.2 +/- 78.6 ml/min, lactate extraction ratio (LER) is 33.1 +/- 13.0%. After norepinephrine infusion at the rate of 0.02microgram/kg/min, VO2 is 157.6 +/- 55.7 ml/min, LER is 29.9 +/- 10.7%. After norepinephrine infusion at the rate of 0.05microgram/kg/min, VO2 is 212.5 +/- 134.5 ml/min, LER is 27.9 +/- 13.4%. Although VO2 and LER are changed in relation to the rate of norepinephrine infusion, there was no statistical significance. CONCLUSIONS: In conclusion, infusion of low dose norepinephrine during coronary artery bypass graft did not produce significant differences in myocardial oxygen consumption and lactate extraction ratio associated with myocardial oxygen balance.

Chest Compression for Post Obstructive Pulmonary Edema: A Case Report / 대한구급학회지

Post obstructive pulmonary edema (POPE) after anesthesia is a rare, but potentially dangerous pulmonary edema during or after relief of severe total or partial upper airway obstruction. The formation of POPE is believed to be the generation of negative intrapleural and intraalveolar pressures which increase the pulmonary transvascular hydrostatic pressure gradient and cause fluid movement to the interstitium and alveoli. Because of both the rapidity and severity with which POPE can develop, prompt recognition and management are essential. A case of POPE after anesthesia in a 23 year-old healthy male undergoing the primary repair of T12 fracture was presented. The patient was extubated without problem after operation. Arrived at the ICU, the patient showed laryngospasm and low oxygen saturation (around 50%). After the intubation with PEEP and the suction of the big amount of pinky frothy transudates through endotracheal tube, oxygen saturation was kept mid 70 s for over 30 minutes. After about 10 times chest compression with suctioning through endotracheal tube, the patient's oxygen saturation showed mid 90 s. This chest compression for the POPE was not recognized by the reference. Even though I can not tell the advantage or disadvantage of this treatment, I report this case for the future reference. After reviewing the reference, the risk factors, differential diagnosis, management and prevention of POPE are discussed.