Effects of different plasma target concentrations of remifentanil on the MACBAR of sevoflurane in children with laparoscopic surgery

Background To investigate the effects of different plasma target concentrations of remifentanil on the minimum alveolar concentration (MAC) for blocking adrenergic response (BAR) of sevoflurane in children with laparoscopic herniorrhaphy. Methods Seventy-five children with 3-7 years old scheduled for laparoscopic herniorrhaphy were randomly divided into group R0, group R1, and group R2 according to different remifentanil plasma target concentration (0, 1, and 2 ngml-1), respectively. The MACBAR of sevoflurane was determined by the up-and-down and sequential method in each group. The concentrations of epinephrine and noradrenaline were also determined at corresponding time points. Results A total of 52 child patients were used among the anticipated 75 patients. In groups R0, R1, and R2, the MACBAR of sevoflurane was (3.29 ± 0.17) %, (2.12 ± 0.10) % and (1.29 ± 0.11) %, respectively, and a significant difference was found among the three groups (P<0.05). The changes of epinephrine and noradrenaline concentrations in each group before and after insufflation of carbon dioxide pneumoperitoneum showed no significant differences. Conclusion Remifentanil by target-controlled infusion can effectively reduce the MACBAR of sevoflurane during laparoscopic surgery in children. At a similar effect of MACBAR, both the changes of epinephrine and noradrenaline concentrations are not affected by the infusion of different remifentanil target concentrations. Trial registration The trial was registered at http://www.chictr.org.cn(ChiCTR1800019393, 8, Nov, 2018).

A Type 2 Ryanodine Receptor Variant in the Helical Domain 2 Associated with an Impairment of the Adrenergic Response

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is triggered by exercise or acute emotion in patients with normal resting electrocardiogram. The major disease-causing gene is RYR2, encoding the cardiac ryanodine receptor (RyR2). We report a novel RYR2 variant, p.Asp3291Val, outside the four CPVT mutation hotspots, in three CPVT families with numerous sudden deaths. This missense variant was first identified in a four-generation family, where eight sudden cardiac deaths occurred before the age of 30 in the context of adrenergic stress. All affected subjects harbored at least one copy of the RYR2 variant. Three affected sisters were homozygous for the variant. The same variant was found in two additional CPVT families. It is located in the helical domain 2 and changes a negatively charged amino acid widely conserved through evolution. Functional analysis of D3291V channels revealed a normal response to cytosolic Ca2+, a markedly reduced luminal Ca2+ sensitivity and, more importantly, an absence of normal response to 8-bromo-cAMP and forskolin stimulation in both transfected HEK293 and HL-1 cells. Our data support that the D3291V-RyR2 is a loss-of-function RyR2 variant responsible for an atypical form of CPVT inducing a mild dysfunction in basal conditions but leading potentially to fatal events through its unresponsiveness to adrenergic stimulation.

Effects of different plasma target concentrations of remifentanil on the MACBAR of sevoflurane in children with laparoscopic surgery

BackgroundTo investigate the effects of different plasma target concentrations of remifentanil on the minimum alveolar concentration (MAC) for blocking adrenergic response (BAR) of sevoflurane in children with laparoscopic herniorrhaphy.MethodsSeventy five children with 3–7 years old scheduled for laparoscopic herniorrhaphy were randomly divided into group R0, group R1, and group R2 according to different remifentanil plasma target concentration (0, 1, and 2 ng/ml), respectively. The MACBAR of sevoflurane was determined by the up-and-down and sequential method in each group. The concentrations of epinephrine and noradrenaline were also determined at corresponding time points.ResultsIn groups R0, R1, and R2, the MACBAR of sevoflurane was (3.29 ± 0.17)%, (2.12 ± 0.10)% and (1.29 ± 0.11)%, respectively, and a significant difference was found among the three groups (P < 0.05). The changes of epinephrine and noradrenaline concentrations in each group before and after insufflation of carbon dioxide pneumoperitoneum showed no significant differences.ConclusionRemifentanil by target-controlled infusion can effectively reduce the MACBAR of sevoflurane during laparoscopic surgery in children. At a similar effect of MACBAR, both the changes of epinephrine and noradrenaline concentrations are not affected by the infusion of different remifentanil target concentrations.Trial registrationThe trial was registered in the China Clinical Trial Center(http://www.chictr.org.cn) in advance (the registry number is ChiCTR1800019393.).

Effects of different sufentanil target concentrations on the MACBAR of sevoflurane in patients with carbon dioxide pneumoperitoneum stimulus

Background This study aims to observe the effects of different target controlled plasma sufentanil concentrations on the minimum alveolar concentration (MAC) of sevoflurane for blocking adrenergic response (BAR) in patients undergoing laparoscopic cholecystectomy with carbon dioxide pneumoperitoneum stimulation. Methods Eighty-five patients undergoing laparoscopic cholecystectomy, aged 30–65 years, with American Society of Anesthesiologists physical status I-II, were enrolled in this study. All the patients were randomly divided into 5 groups (S0, S1, S2, S3, S4) with different sufentanil plasma target concentration (0.0, 0.1, 0.3, 0.5, 0.7 ng ml− 1). Anesthesia was induced by inhalation of 8% sevoflurane in 100% oxygen, and 0.6 mg kg− 1 of rocuronium was intravenously injected to facilitate the insertion of a laryngeal mask airway. The end-tidal sevoflurane concentration and sufentanil plasma target concentration were adjusted according to respective preset value in each group. The hemodynamic response to pneumoperitoneum stimulus was observed after the end-tidal sevoflurane concentration had been maintained stable at least for 15 min. The MACBAR of sevoflurane was measured by a sequential method. Meanwhile, epinephrine (E) and norepinephrine (NE) concentrations in the blood were also determined before and after pneumoperitoneum stimulus in each group. Results When the method of independent paired reversals was used, the MACBAR of sevoflurane in groups S0, S1, S2, S3, S4 was 5.333% (confidence interval [CI] 95%: 5.197–5.469%), 4.533% (95% CI: 4.451–4.616%), 2.861% (95% CI: 2.752–2.981%), 2.233% (95% CI: 2.142–2.324%) and 2.139% (95% CI: 2.057–2.219%), respectively. Meanwhile, when the isotonic regression analysis was used, the MACBAR of sevoflurane in groups S0, S1, S2, S3, S4 was 5.329% (95% CI: 5.321–5.343%), 4.557% (95% CI: 4.552–4.568%), 2.900% (95% CI: 2.894–2.911%), 2.216% (95% CI: 2.173–2.223%) and 2.171% (95% CI: 2.165–2.183%), respectively. The MACBAR was not significantly different between groups S3 and S4 when using 0.5 and 0.7 ng ml− 1 of sufentanil plasma target concentrations. No significant difference was found in the change of E or NE concentration between before and after pneumoperitoneum stimulation in each group. Conclusions The MACBAR of sevoflurane can be decreased with increasing sufentanil plasma target concentrations. A ceiling effect of the decrease occurred at a sufentanil plasma target concentration of 0.5 ng ml− 1. When the sympathetic adrenergic response was inhibited in half of the patients to pneumoperitoneum stimulation in each group, the changes of E and NE concentrations showed no significant differences. Trial registration The study was registered at http://www.chictr.org.cn (ChiCTR1800015819, 23, April, 2018).

Effects of different sufentanil target concentrations on the MACBAR of sevoflurane in patients with carbon dioxide pneumoperitoneum stimulus

Background: This study aims to observe the effects of different target controlled plasma sufentanil concentrations on the minimum alveolar concentration (MAC) of sevoflurane for blocking adrenergic response (BAR) in patients undergoing laparoscopic cholecystectomy with carbon dioxide pneumoperitoneum stimulation.Methods: Eighty-five patients undergoing laparoscopic cholecystectomy, aged 30-65 years, with American Society of Anesthesiologists physical status Ⅰ-Ⅱ, were enrolled in this study. All the patients were randomly divided into 5 groups (S0, S1, S2, S3, S4) with different sufentanil plasma target concentration (0.0, 0.1, 0.3, 0.5, 0.7 ng ml-1). Anesthesia was induced by inhalation of 8% sevoflurane in 100% oxygen, and 0.6 mg kg-1 of rocuronium was intravenously injected to facilitate the insertion of a laryngeal mask airway. The end-tidal sevoflurane concentration and sufentanil plasma target concentration were adjusted according to respective preset value in each group. The hemodynamic response to pneumoperitoneum stimulus was observed after the end-tidal sevoflurane concentration had been maintained stable at least for 15 min. The MACBAR of sevoflurane was measured by a sequential method. Meanwhile, epinephrine (E) and norepinephrine (NE) concentrations in the blood were also determined before and after pneumoperitoneum stimulus in each group.Results: When the method of independent paired reversals was used, the MACBAR of sevoflurane in groups S0, S1, S2, S3, S4 was 5.333% (confidence interval [CI] 95%: 5.197-5.469%), 4.533% (95% CI: 4.451-4.616%), 2.861% (95% CI: 2.752-2.981%), 2.233% (95% CI: 2.142-2.324%) and 2.139% (95% CI: 2.057-2.219%), respectively. Meanwhile, when the isotonic regression analysis was used, the MACBAR of sevoflurane in groups S0, S1, S2, S3, S4 was 5.329% (95% CI: 5.321-5.343%), 4.557% (95% CI: 4.552-4.568%), 2.900% (95% CI: 2.894-2.911%), 2.216% (95% CI: 2.173-2.223%) and 2.171% (95% CI: 2.165-2.183%), respectively. The MACBAR was not significantly different between groups S3 and S4 when using 0.5 and 0.7 ng ml-1 of sufentanil plasma target concentrations. No significant difference was found in the change of E or NE concentration between before and after pneumoperitoneum stimulation in each group.Conclusions: The MACBAR of sevoflurane can be decreased with increasing sufentanil plasma target concentrations. A ceiling effect of the decrease occurred at a sufentanil plasma target concentration of 0.5 ng ml-1. When the sympathetic adrenergic response was inhibited in half of the patients to pneumoperitoneum stimulation in each group, the changes of E and NE concentrations showed no significant differences.Trial registration: The study was registered at http://www.chictr.org.cn (ChiCTR1800015819, 23, April, 2018).