Objective The study was to compare the effect of sufentanil and morphine preconditioning on ischemia /reperfusion-induced ventricular arrhythmias and the expression and distribution of myocardial Cx43 in rats.The regulation mechanisms that how sufentail and morphine lead to the change of Cx43 were also studied.Methods 32 male SD rats were randomly divided into 4 groups:sham operation group (group C),ischemia/reperfusion (group I/R),morphine preconditioning group(group M) and sufentanil preconditioning group(group S),each group had 8 rats.Established myocardial ischemia/reperfusion model,continuous recorded Ⅱ ECG,mean arterial pressure(MAP) and heart rate(HR).The ventricular arrhythmias at the 30 min before reperfusion was observed and the ventricular arrhythmias score of each group was calculated by ECG analysis; expression and distribution of Cx43 protein were observed by immunohistochemical technique.Results Compared with group C,the HR,MAP,RPP of group I/R were decreased obviously (P < 0.05),while the arrhythmia score was significantly higher(P < 0.05).Compared with group I/R,the extent of the declined of HR,MAP,RPP of group M and group S were eased significantly(P < 0.05) and arrhythmia score was significantly lower(P < 0.05).The HR,MAP,RPP of group M and group S are closer(P > 0.05).Compared with the group C,Cx43 expression level in group I/R was significantly reduced (P < 0.05) and the distribution was disordered,while compared with the group I/R,Cx43 expression level in group M and group S were significantly increased (P < 0.05),and its distribution was structured.In group M and group S,Cx43 expression level were closer(P > 0.05) and so as their distribution.Conclusion Sufentanil and morphine could inhibit the reduction of myocardial Cx43 expression level and improve its distribution which could played an important role in anti-arrhythmic during ischemia-reperfusion.
Key words:
Sufentanil; Morphine; Myocardial reperfusion injury ; Connexin 43
Objective
To evaluate the effect of hyperbaric oxygen (HBO) therapy on postoperative cognitive dysfunction (POCD) in elderly patients undergoing general anesthesia.
Methods
A total of 112 patients, aged 65-75 yr, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, undergoing elective non-cardiac surgery with general anesthesia, were randomly divided into control group (C group, n=54) and HBO group (n=58). Patients were exposed to hyperbaric oxygen in a hyperbaric oxygen chamber once a day from day 3 to day 12 after surgery in both groups.Pressure was slowly increased to 2 atmosphere absolute within 20 min, pure oxygen was inhaled for 35 min by mask, 5 min later pure oxygen was inhaled for another 35 min, oxygen inhalation was then stopped and pressure was slowly increased to 1 atmosphere absolute in HBO group.Patients inhaled air at 1 atmosphere absolute for 70 min in C group.Cognitive function score was assessed using Mini-Mental State Examination, language ability test, visual identification function test, digit span backwards task and Hasegawa′s Dementia Scale (HDS) at 2 days before surgery and 7 and 13 days after surgery.The development of POCD was recorded.
Results
Compared with the baseline at 2 days before surgery, language ability test, digit span backwards task and HDS scores were significantly decreased at 7 and 13 days after surgery in C group, and digit span backwards task scores were significantly decreased at 7 days after surgery in HBO group(P<0.05 or 0.01). The language ability test and HDS scores were significantly higher, and the incidence of POCD was lower at 7 and 13 days after surgery in HBO group than in C group (P<0.05).
Conclusion
HBO therapy can reduce POCD in elderly patients undergoing general anesthesia.
Key words:
Hyperbaric oxygen; Aged; Anesthesia, general; Cognitive disorders
Background: Norepinephrine and phenylephrine are widely used for obstetric anesthesia. Our central objective was to determine the ED (effective dose) 90 and potency ratio of prophylactic norepinephrine and phenylephrine boluses for preventing postspinal anesthesia hypotension during cesarean section. Methods: Patients scheduled for elective cesarean section (n = 80) were randomly allocated to receive prophylactic norepinephrine (NE) or phenylephrine (PE) boluses immediately after induction of spinal anesthesia. An initial dose of NE (3 μg) and PE (37.5 μg) was given to the first patient, and an up-and-down sequential allocation method was used to determine the next dose level according to the responses (the effectiveness for preventing postspinal anesthesia hypotension [defined as SBP < 80% of baseline value]). Primary outcomes were ED90 and the potency ratio of prophylactic norepinephrine and phenylephrine boluses. Secondary outcomes were the incidence of postspinal anesthesia hypotension, severe postspinal anesthesia hypotension, nausea, vomiting, bradycardia, hypertension, umbilical artery blood gas values, and Apgar scores. Results: The ED90 values for prophylactic norepinephrine and phenylephrine boluses were 8.0 μg (95% CI 7.1– 11.0 μg) and 90.9 μg (95% CI 82.0– 123.9 μg), respectively. The estimated relative potency ratio was 11.4:1. The incidence of bradycardia was lower in the NE group (2.5% vs 20%, P = 0.034). Other outcomes were comparable between the two groups. Conclusion: An 8-μg prophylactic bolus of norepinephrine and a 90-μg prophylactic bolus of phenylephrine can effectively prevent postspinal anesthesia hypotension in patients during cesarean section. Keywords: cesarean section, norepinephrine, phenylephrine, postspinal anesthesia hypotension
Fluid loading is an essential component of treatment for reducing the incidence of post-spinal anesthesia hypotension and is necessary to maintain intravascular volume, perfuse tissues, and control spinal anesthesia hypotension after sympathetic blockade. We performed a randomized sequential allocation dose-finding study to compare the effects of 10 mL/kg crystalloid and 6% hydroxyethyl starch (130/0.4) co-load on the ED90 of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery.Eighty patients were randomly allocated to receive either a 10 mL/kg crystalloid (Crystalloid Group, n = 40) or 6% hydroxyethyl starch (130/0.4) (Colloid Group, n = 40) co-load combined with prophylactic norepinephrine infusion during spinal anesthesia for cesarean delivery. The first patient received an initial prophylactic norepinephrine infusion rate of 0.025 μg/kg/min. Subsequent patients received a 0.005 μg/kg/min gradient dose of prophylactic norepinephrine. This dose was administered as a gradient based on its effectiveness for preventing post-spinal anesthesia hypotension (defined as SBP < 80% of baseline value) and determined by the up-and-down sequential allocation methodology. The primary study outcome was the ED90 of prophylactic norepinephrine infusion. Secondary outcomes included the incidence of post-spinal anesthesia hypotension, bradycardia, hypertension, Apgar scores, and umbilical artery blood gas values were also measured.The ED90 values of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery were 0.063 μg (95% CI: 0.050 to 0.064) and 0.062 μg (95% CI: 0.045 to 0.064) using isotonic regression analysis, and 0.068 μg (95% CI: 0.056 to 0.353) and 0.060 μg (95% CI: 0.050 to 3.590) using probit regression analysis in the Crystalloid Group and Colloid Group, respectively. The secondary outcomes were comparable between the two groups.The administration of a 10 mL/kg 6% hydroxyethyl starch (130/0.4) does not provide additional benefits compared to crystalloid co-load in reducing the ED90 of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery.