Discussion
cardiac ischemic injury, shock, hypotension, mis-match, obstructive jaundice
SHOCK, OBSTRUCTIVE JAUNDICE
The current study suggests that prophylactic administration of methylene blue helps to maintain hemodynamic stabilization during procedures of relieving obstructive jaundice and thus improves renal and hepatic function, attenuating cardiac ischemic injury the after the operation, and shortened the ICU stay.Patients with obstructive jaundice are at high risk for impairment of cardiovascular and low vascular response under anesthesia conditions and often need high dose of vasopressors to maintain stabilization of hemodynamic. It has been reported that a high requirement for vasoactive drugs is associated with increased mortality and organ’s function, which is due to that excessive vasoconstriction might be deleterious to micro-circulation and lead to mis-match between macro-circulation and micro-circulation during shock conditions.In clinic practice, noradrenaline is a first-line drug to correct hypotension associated with reduced SVRMethylene blue has been suggested as an adjuvant treatment in the setting of refractory hypotension.Some limitations of this study are the following. Firstly, this is single-center study with small sample size. Second, methylene blue was administrated before anesthesia induction; the risk and benefit of the patients with low risk of refractory hypotension remain unknown. Thirdly, the effects of methylene blue on long-term outcomes are also unknown and warrant further study. Fourthly, methylene blue may interfere some measurements, including pulse oximetry reading and alter the color of body fluid, such as urine; all these need to be closely monitored using its use and more cautions are needed to take. Lastly, some of the patients underwent pre-operation ERCP in both groups, because the number of patients who received pre-operation ERCP was not big enough to stratified analyze the effects of methylene blue and pre-operation ERCP.Although owing to mentioned limitations, methylene blue may be recommended to be used to improve hemodynamic stabilization during operation and organ’ function in the patients undergoing operations relieving obstructive jaundice, but further clinical study is still needed to verify its long-term benefits.