Effect of N-acetylcysteine on pulmonary function in patients undergoing off-pump coronary artery bypass surgery.

BACKGROUND: Pulmonary dysfunction related to inflammatory response and radical oxygen species remains a problem in off-pump coronary bypass graft surgery (OPCAB), especially in patients with reduced left ventricular (LV) function. The aim of this study was to evaluate the effect of N-acetylcysteine (NAC) on pulmonary function following OPCAB. METHODS: Patients with LV ejection fraction ≤40% were randomly assigned to receive either a bolus of 100 mg/kg of intravenous NAC over a 15-min period immediately after anesthetic induction, followed by an intravenous infusion at 40 mg/kg/day for 24 h (NAC group, n=24), or a placebo (control group, n=24). Hemodynamic and pulmonary parameters, and the incidence of acute lung injury (PaO(2)/FiO(2)<300 mmHg) were assessed and compared. RESULTS: The pulmonary vascular resistance index (PVRI) did not change during mechanical heart displacement compared with the baseline value in the NAC group while it was significantly increased in the control group. Significantly less number of patients developed acute lung injury at 2 h after the surgery in the NAC group. The other pulmonary parameters and the duration of ventilator care were all similar. CONCLUSIONS: NAC demonstrated promising results in terms of mitigating the increase in PVRI during mechanical heart displacement and attenuating the development of acute lung injury in the immediate post-operative period. However, NAC could not induce a definite improvement in the other important pulmonary variables including PaO(2)/FiO(2) and Q(s)/Q(t), and did not lead to a decreased duration of ventilatory care or length of stay in the intensive care unit.

Peri-operative oral triiodothyronine replacement therapy to prevent postoperative low triiodothyronine state following valvular heart surgery.

This study evaluated the effect of oral triiodothyronine (T(3)) replacement therapy, starting on the day of the surgery, on thyroid hormone concentrations and clinical outcome in high-risk patients undergoing valvular heart surgery. Fifty patients were randomly allocated to either T(3) or placebo. In the treatment (T(3)) group patients received 20 microg of oral or nasogastric T(3) every 12 h starting just before induction of anaesthesia and until the first day after surgery. T(3) concentrations were significantly higher in the T(3) group than the placebo group from 1 to 36 h after removal of the aortic cross clamp. The number of patients requiring vasopressin after discontinuing cardiopulmonary bypass was significantly greater in the placebo group than the T(3) group. Significantly fewer patients required vasopressors in the T(3) group on the first day after surgery.

Relationship between echocardiographic index of ventricular filling pressure and intraoperative haemodynamic changes during off-pump coronary bypass surgery.

BACKGROUND: The ratio of mitral velocity to early-diastolic velocity of the mitral annulus (E/e') is an indicator of diastolic function representing acute loading conditions of the left ventricle. We tested the efficacy of E/e' as a predictor of haemodynamic derangement during off-pump coronary artery bypass surgery (OPCAB), when heart displacement causes loading changes. METHODS AND RESULTS: Fifty patients with left ventricular (LV) ejection fraction >or= 50% were divided into two groups; E/e'<8 (normal LV filling pressure, n=25) and >15 (increased LV filling pressure, n=25). Haemodynamic measurements were recorded after induction of anaesthesia, during grafting, and after sternum closure. Patients' characteristics and operative data were similar between the groups. Cardiac index and mixed venous oxygen saturation were significantly lower during grafting and after sternum closure in the E/e'>15 group, compared with E/e'<8 group and with the baseline values. The E/e'>15 group required significantly longer ventilation time and length of stay in the intensive care unit. CONCLUSIONS: Even in patients with preserved systolic LV function, patients with E/e'>15 were more prone to undergo a significant decrease in cardiac output during OPCAB, which did not return to baseline level after completion of grafting. Whether this finding is associated with increased morbidity and mortality should be validated.

Epidural sufentanil provides better analgesia from 24 h after surgery compared with epidural fentanyl in children.

BACKGROUND: Studies comparing epidural fentanyl and sufentanil in adults reported a similar analgesic effect with variable side effects. We hypothesized that epidural fentanyl and sufentanil will have a similar analgesic effect in children undergoing urological surgery. METHODS: Sixty-four children undergoing urological surgery were randomized into two groups: fentanyl in ropivacaine (fentanyl group, n=32) and sufentanil in ropivacaine (sufentanil group, n=32). After anaesthesia, an epidural catheter was inserted at the L2-3, L3-4 or L4-5 interspace. For post-operative pain relief, a solution consisting of fentanyl 0.1 mcg/kg/ml or sufentanil 0.015 mcg/kg/ml in 1.5 mg/ml ropivacaine was infused at a rate of 2 ml/h. To assess post-operative pain, the faces pain scale and the face, legs, activity, cry, consolability score were recorded at 1, 6, 24, 48 and 72 h after surgery. The incidence of adverse effects such as hypoxia, sedation, pruritus, nausea and/or vomiting was also evaluated. RESULTS: Pain scores demonstrated no significant difference between the groups. The need for rescue analgesia during 24-72 h was higher in the fentanyl group than in the sufentanil group (6/32 vs. 0/32, P=0.012). The incidence of pruritus was higher in the sufentanil group compared with that in the fentanyl group (5/32 vs. 0/32). CONCLUSIONS: Epidural sufentanil provides better analgesia from 24 h after surgery compared with epidural fentanyl in infants and children undergoing urological surgery. The incidence of pruritus in the sufentanil group was higher than that in the fentanyl group.

Significance of the injection timing of ephedrine to reduce the onset time of rocuronium.

We postulated that the onset time of rocuronium can be accelerated effectively if it is administered at the time when the effect of ephedrine on cardiac output has reached its maximum. Seventy-five male, anaesthetised, patients were randomly allocated to three groups. Ephedrine 70 microg.kg(-1) was administered at 4 min (Early) or 30 s (Late) before administering rocuronium. The control group received saline at 4 min and at 30 s before rocuronium. The onset time of rocuronium in the Early group was significantly shorter than in the Control group, but there was no difference in the onset time between the Late and Control groups. There were no significant differences in the intubating conditions of the three groups. Ephedrine 70 microg.kg(-1) can reduce the onset time of rocuronium effectively if rocuronium is administered at 4 min following the ephedrine injection, when the effect of ephedrine on cardiac output is expected to reach its maximum.

Costimulatory effect of Fas in mouse T lymphocytes.

To induce proper immune responses, T lymphocytes require two types of stimuli, antigen-specific and costimulatory signals. Among costimulatory molecules, CD28-engagement promotes the survival and proliferation of both naive and memory T cells. In addition, it is now believed that Fas may play a role in T cell activation in the human system. It is, however, controversial whether Fas can act as a costimulatory signal in the murine system. Thus, we investigated fundamental differences in the capacity to induce proliferation of T cells between Fas and CD28 in mice. Fas-mediated T cell proliferation was observed only with a full mitogenic dose of anti-CD3 antibodies, whereas CD28 engagement was able to enhance T cell proliferation in the presence of a suboptimal level of anti-CD3 antibody. Furthermore, Fas-engaged T cells showed faster response in the upregulation of CD25 and CD69 expression than CD28-engaged ones. Here, we report that Fas might play a role in mature T cell activation in the mouse system through a different mechanism from that in CD28 costimulation.