Effects of individualized positive end-expiratory pressure on intraoperative oxygenation and postoperative pulmonary complications in patients requiring pneumoperitoneum with Trendelenburg position: A systematic review and meta-analysis.

BACKGROUND: Whether individualized positive end-expiratory pressure (PEEP) improves intraoperative oxygenation and reduces postoperative pulmonary complications (PPCs) remains unclear. This systematic review and meta-analysis examined whether individualized PEEP is associated with improved intraoperative oxygenation and reduce PPCs for patients needing pneumoperitoneum with the Trendelenburg position during surgery. METHODS: Medline, Embase, the Cochrane Library, and www.clinicaltrials.gov were searched for randomized controlled trials evaluating the effects of individualized PEEP on intraoperative oxygenation and PPCs in patients who required Trendelenburg positioning with pneumoperitoneum. The primary outcome was the oxygenation (PaO2/FiO2) during the procedure. Secondary outcomes included PPCs, intraoperative respiratory mechanics (driving pressure, compliance), and vasopressor consumption. DerSimonian-Laird random effects models were used to calculate mean differences (MDs) and log risk ratios (log RRs) with 95% confidence intervals (CIs). The Cochrane Risk-of-Bias tool 2.0 was applied to assess the risk of bias in included studies. The protocol of this meta-analysis has been registered in PROSPERO. RESULTS: We included 14 studies (1121 patients) that employed different individualized PEEP strategies. Compared with control groups, individualized PEEP groups exhibited a significantly improved intraoperative PaO2/FiO2 (MD=56.52 mm Hg, 95% CI: [33.98, 79.06], P<0.001) and reduced incidence of PPCs (log RR=-0.50, 95% CI: [-0.84, -0.16], P=0.004). Individualized PEEP reduced driving pressure while improving respiratory compliance. Intraoperative vasopressor consumption was similar between both groups. The weighted mean PEEP in the individual PEEP groups was 13.2 [95% CI, 11.7, 14.6] cmH2O. No evidence indicated that one individualized PEEP strategy is superior to others. CONCLUSIONS: Individualized PEEP seems to work positively for lung protection in the Trendelenburg position and pneumoperitoneum in patients undergoing general anesthesia.

Dopamine attenuates ethanol-induced neuroapoptosis in the developing rat retina via the cAMP/PKA pathway.

Apoptosis has been identified as the primary cause of fetal alcohol spectrum disorder (FASD), and the development of methods to prevent and treat FASD have been based on the mechanisms of alcohol-induced apoptosis. The present study aimed to explore the effects of dopamine on alcohol­induced neuronal apoptosis using whole­mount cultures of rat retinas (postnatal day 7). Retinas were initially incubated with ethanol (100, 200 or 500 mM), and in subsequent analyses retinas were co­incubated with ethanol (200 mM) and dopamine (10 µM). In addition, several antagonists and inhibitors were used, including a D1 dopamine receptor (D1R) antagonist (SCH23390; 10 µM), a D2R antagonist (raclopride; 40 µM), an adenosine A2A receptor (AA2AR) antagonist (SCH58261; 100 nM), an adenylyl cyclase (AC) inhibitor (SQ22536; 100 µM) and a PKA inhibitor (H­89; 1 µM). The results demonstrated that exposure increased neuroapoptosis in the retinal ganglion cell layer (GCL) in a dose­dependent manner. Dopamine treatment significantly attenuated ethanol­induced neuronal apoptosis. D1R, D2R and AA2AR antagonists partially inhibited the protective effects of dopamine against ethanol­induced apoptosis; similar results were observed with AC and PKA inhibitor treatments. In summary, the present study demonstrated that dopamine treatment may be able to attenuate alcohol­induced neuroapoptosis in the developing rat retina by activating D1R, D2R and AA2AR, and by upregulating cyclic AMP/protein kinase A signaling.

Dopamine Attenuates Ketamine-Induced Neuronal Apoptosis in the Developing Rat Retina Independent of Early Synchronized Spontaneous Network Activity.

Deprivation of spontaneous rhythmic electrical activity in early development by anesthesia administration, among other interventions, induces neuronal apoptosis. However, it is unclear whether enhancement of neuronal electrical activity attenuates neuronal apoptosis in either normal development or after anesthesia exposure. The present study investigated the effects of dopamine, an enhancer of spontaneous rhythmic electrical activity, on ketamine-induced neuronal apoptosis in the developing rat retina. TUNEL and immunohistochemical assays indicated that ketamine time- and dose-dependently aggravated physiological and ketamine-induced apoptosis and inhibited early-synchronized spontaneous network activity. Dopamine administration reversed ketamine-induced neuronal apoptosis, but did not reverse the inhibitory effects of ketamine on early synchronized spontaneous network activity despite enhancing it in controls. Blockade of D1, D2, and A2A receptors and inhibition of cAMP/PKA signaling partially antagonized the protective effect of dopamine against ketamine-induced apoptosis. Together, these data indicate that dopamine attenuates ketamine-induced neuronal apoptosis in the developing rat retina by activating the D1, D2, and A2A receptors, and upregulating cAMP/PKA signaling, rather than through modulation of early synchronized spontaneous network activity.

A comparison of classic laryngeal mask airway insertion between lightwand- and standard index finger-guided techniques.

STUDY OBJECTIVE: To compare the efficacy of lightwand-guided classic laryngeal mask airway (cLMA) real-time insertion technique with the standard recommended index finger-guided insertion technique. DESIGN: Prospective, randomized controlled study. SETTING: University-affiliated hospital. PATIENTS: Three hundred patients undergoing minor gynecological or orthopedic surgeries under general anesthesia using the cLMA as an airway management tool. INTERVENTIONS: Patients were randomly divided into either lightwand-guided group or standard group. MEASUREMENTS: Fiberoptic bronchoscopy was used to determine the cLMA position after a cLMA was inserted. The first attempt and total success rates of the cLMA insertion, insertion time, distances from the end of cLMA pilot tube to the upper central incisors, views of fiberoptic bronchoscopy, blood staining, tidal volume, airway pressure, end-tidal CO2, SpO2, noninvasive hemodynamic parameters, and others were compared. MAIN RESULTS: The cLMA was all successfully inserted within 3 attempts except for 2 patients in the standard group. The success rates of lightwand-guided insertion technique at first attempt were significantly higher than standard insertion technique; the ideal view rates assessed by fiberoptic bronchoscopy in lightwand-guided group patients were also significantly higher than in standard group patients, but the insertion time of first successful attempt was similar; the blood staining rates on the cLMA in lightwand-guided group patients were significantly less than in standard group patients. The depths of cLMA insertion in standard group patients were significantly deeper than those in lightwand-guided group patients. There was no significant difference in end-tidal CO2, SpO2, airway pressure, and hemodynamic variables. CONCLUSION: Lightwand-guided cLMA insertion technique can provide a more objective indicator for correct cLMA positioning, higher first attempt success rates, better glottic views, and less damage to oropharyngeal or esophagus tissues than standard index finger-guided cLMA insertion technique.