Effects of nalbuphine on the cardioprotective effect of morphine in rats

Analgesic Effects and Safety of Dexmedetomidine Added to Nalbuphine or Sufentanil Patient-Controlled Intravenous Analgesia for Children After Tonsillectomy Adenoidectomy

Tonsillectomy is a frequently performed surgical procedure in children, requiring post-operative analgesia. This study evaluated the efficacy and safety of nalbuphine or sufentanil combined with dexmedetomidine for patient-controlled intravenous analgesia (PCIA) after pediatric tonsillectomy adenoidectomy. A total of 400 patients undergoing tonsillectomy with and without adenoidectomy were included in the study. Patients received a PCIA pump (0.5 mg/kg nalbuphine, 2 μg/kg dexmedetomidine and 0.9% sodium chloride to a total volume of 100 ml) for postoperative pain management were classified into Group ND (n = 200). Patients received a PCIA pump (2 μg/kg sufentanil, 2 μg/kg dexmedetomidine and 0.9% sodium chloride to a total volume of 100 ml) for postoperative pain management were classified into Group SD (n = 200). More stable hemodynamic changes were noted in Group ND than Group SD from 1 h to 48 h after operation. At 6, 12, 24, and 48 h after operation, the children in Group ND had higher Ramsay sedation scores than those in Group SD. The times to push the PCIA button in Group ND and Group SD were 2.44 ± 0.74 and 2.62 ± 1.00, showing significant differences (p = 0.041). The VASR scores of children in Group ND were significantly lower within 6, 12, and 24 h than those in Group SD (p < 0.05). The VASC scores of children in Group ND were significantly lower within four time points (2, 6, 12, and 24 h) than those in Group SD (p < 0.05). At 1st day after surgery, the children in Group ND had lower levels of serum ACTH, IL-6, and COR levels than those in Group SD (p < 0.001). The incidence rates of nausea and vomiting, and pruritus were significantly higher in Group SD than Group ND (5.00% vs. 11.00%, p = 0.028; 1.00% vs. 4.50%, p = 0.032). The total incidence rate of adverse reactions was significantly higher in Group SD than Group ND (15.00% vs. 31.00%, p = 0.0001). The study demonstrated that dexmedetomidine added to nalbuphine PCIA enhanced the analgesic effects, attenuated the postoperative pain, and reduced the stress response after pediatric tonsillectomy adenoidectomy.

Effects of nalbuphine on the cardiotoxicity of ropivacaine in rats

When combined with nalbuphine, local anesthetics show a longer duration of nerve block without increasing complications. However, no evidence is available concerning the effect of nalbuphine on the cardiotoxicity of local anesthetics. The objective of this work is to investigate whether nalbuphine pretreatment can increase the lethal dose threshold of ropivacaine in rats. Anesthetized Sprague Dawley rats were pretreated with different doses of nalbuphine (0.4, 0.8, 1.5, 3.0, 5.0 mg/kg) or NS (normal saline, negative control) or 30% LE (lipid emulsion, positive control) 2 ml/kg/min for 5 min (n = 6). Then 0.5% ropivacaine was infused at a rate of 2.5 mg/kg/min until asystole occurs. Time of arrhythmia, 50% mean arterial pressure- and 50% heart rate-reduction, and asystole were recorded, and ropivacaine doses were calculated. Nalbuphine (0.4-5.0 mg/kg) did not affect ropivacaine-induced arrhythmia, 50% mean arterial pressure-reduction and 50% heart rate-reduction, and asystole in rats compared with NS pre-treatment. The asystole dose threshold (in milligrams per kilogram) of group LE was higher than that of group NS (NS 28.25(6.32) vs. LE, 41.58(10.65); P = 0.04; 95% confidence interval 0.23 to 26.45), while thresholds of arrhythmia, 50% mean arterial pressure-reduction, and 50% heart rate-reduction were not affected by LE. Nalbuphine doses of 0.4-5.0 mg/kg pretreatment did not increase the threshold of ropivacaine cardiotoxicity compared with NS control; 30% LE increases the lethal dose threshold of ropivacaine in rats.

Do We Really Need Aspirin Loading for STEMI?

Aspirin loading (chewable or intravenous) as soon as possible after presentation is a class I recommendation by current ST elevation myocardial infarction (STEMI) guidelines. Earlier achievement of therapeutic antiplatelet effects by aspirin loading has long been considered the standard of care. However, the effects of the loading dose of aspirin (alone or in addition to a chronic maintenance oral dose) have not been studied. A large proportion of myocardial cell death occurs upon and after reperfusion (reperfusion injury). Numerous agents and interventions have been shown to limit infarct size in animal models when administered before or immediately after reperfusion. However, these interventions have predominantly failed to show significant protection in clinical studies. In the current review, we raise the hypothesis that aspirin loading may be the culprit. Data obtained from animal models consistently show that statins, ticagrelor, opiates, and ischemic postconditioning limit myocardial infarct size. In most of these studies, aspirin was not administered. However, when aspirin was administered before reperfusion (as is the case in the majority of studies enrolling STEMI patients), the protective effects of statin, ticagrelor, morphine, and ischemic postconditioning were attenuated, which can be plausibly attributable to aspirin loading. We therefore suggest studying the effects of aspirin loading before reperfusion on the infarct size limiting effects of statins, ticagrelor, morphine, and/ or postconditioning in large animal models using long reperfusion periods (at least 24 h). If indeed aspirin attenuates the protective effects, clinical trials should be conducted comparing aspirin loading to alternative antiplatelet regimens without aspirin loading in patients with STEMI undergoing primary percutaneous coronary intervention.