Laryngeal Mask Breathing Dynamics

Partâ… The comparison of respiratory mechanics between laryngeal mask airway and tracheal intubation in pediatric strabismus surgeryObjective To evaluate the effects of laryngeal mask airway(LMA) and tracheal intubation(TI) on hemodynamics,respiratory mechanics and complications in pediatric strabismus surgery.Methods Sixty patients(ASA classâ… orâ…¡),scheduled for selective strabismus surgery under general anesthesia were allocated randomly to either laryngeal mask airway group(LMA,n = 30) or tracheal intubation group(TI,n=30) with mechanial ventilation.Anesthesia was induced by sevoflurane and remifentanil in LMA group,or by sevoflurane,remifentanil and succinylcholine in TI group.Anesthesia was maintained with remifentanil(0.25μg·kg^-1 ? min^-1)and sevoflurane(2%),in freshgas O₂(1L/min).MAP and HR were recorded before anesthesia induction,before intubation,after intubation immediately,befor extubation and after extubation immediately.Parameters for respiratory mechanics including peak inspiratory pressure(PIP),plateau airway pressure(P_plateau),mean airway pressure(P_mean),positive end expiratory pressure (PEEP),peak inspiratory flow(FI_max),peak expiratory flow(FE_max),end tidal CO₂ (EtCO₂) were recorded 5 min,10min,15mins after intubation.Meanwhile,arterial gas analysis were examined.Complications such as aspiration,bucking,pharyngeal pain,hoarseness,muscular soreness and unseal of LMA were followed up 24h after extubation.Results MAP,HR were significantly higher in group TI than those in group LMA after intubation and extubation(P＜0.05).PIP,P_plateau,P_mean,V_D/V_T,R_e were significantly higher in group TI than those in group LMA(P＜0.05).Complications such as bucking,pharyngeal pain and muscular soreness were significantly lower in LMA group than that in TI group(P＜0.05).There were no differences in maintenance phase rspiratory mechanics variable among the two groups respectively(P＞0.05).Conclusion LMA application is simple,with minor laryngeal stimulation during intubation and extubation,with more stable hemodynamics,with reliable respiratory mechanics,and reduce the incidence of postoperative upper airway complications following general anesthesia for pediatric strabismus surgery. Partâ…¡The comparison of respiratory mechanics between flexible reinforced laryngeal mask airway and tracheal intubation in functional endoscopic sinus surgeryObjective To evaluate the effects of flexible reinforced laryngeal mask airway(FRLMA) and tracheal intubation(TI) on hemodynamics,respiratory mechanics and complications in functional endoscopic sinus surgery.Methods Fourty-six patients(ASA classâ… orâ…¡),scheduled for selective functional endoscopic sinus surgery under general anesthesia were allocated randomly to either flexible reinforced laryngeal mask airway group(FRLMA,n = 23) or tracheal intubation group(TI,n=23) with mechanical ventilation.Anesthesia was induced by propofol and fentanyl in FRLMA group,or by propofol,fentanyl and succinylcholine in TI group.Anesthesia was maintained with remifentanil(0.25μg ? kg^-1 ? min^-1) and sevoflurane(2%),in fresh gas O₂(1L/min).MAP and HR were recorded before anesthesia induction,before intubation,after intubation immediately,before extubation and after extubation immediately.Parameters for respiratory mechanics including peak inspiratory pressure(PIP),plateau airway pressure(P_plateau),mean airway pressure(P_mean),positive end expiratory pressure(PEEP),peak inspiratory flow(FI_max),peak expiratory flow(FE_max),end tidal CO₂(EtCO₂) were recorded 5 min,10min,15mins after intubation.Meanwhile,arterial gas analysis were examined. Complications such as aspiration,bucking,pharyngeal pain,hoarseness,muscular soreness and unseal of FRLMA were followed up 24h after extubation.Results MAP,HR were significantly higher in group TI than those in group FRLMA after intubation and extubation(P＜0.05).PIP,P_plateau,P_mean,V_D/V_T were significantly higher in group TI than those in group FRLMA(P＜0.05).Complications such as bucking, pharyngeal pain and muscular soreness were significantly lower in FRLMA group than that in TI group(P＜0.05).Conclusion The application of FRLMA on functional endoscopic sinus surgery is a simply,handling method,with minor laryngeal stimulation during intubation and extubation,more stable hemodynamics,reliable respiratory mechanics and low incidence of postoperative upper airway complications.