Effekt av alveolær rekrutteringsmanøver under generell anestesi - en systematisk kunnskapsoppsummering

Bakgrunn: Generell anestesi og mekanisk ventilering fører til kollaps av alveolært lungevev hos 85-90 % av alle intuberte pasienter. Konsekvensene av dette er redusert gassutveksling i tillegg til økt fare for alvorlige postoperative lungekomplikasjoner. Såkalt lungebevarende ventilasjon og rekrutteringsmanøver er en etablert praksis for behandling av ARDS. Nå vurderes det om denne strategien også kan være nyttig for lungefriske under kirurgi og narkose. Målsetting: Målet for dette studiet var å vurdere effekten av en lungerekrutteringsmanøver hos kirurgiske pasienter i generell anestesi. Metode: Vi utførte en systematisk kunnskapsoppsummering basert på retningslinjer fra The Cochrane Collaborate. Systematiske søk ble gjort i databasene Cochrane, Medline, Embase, Cinahl og Scopus fra 2005 til februar 2016. Totalt ni randomiserte kontrollerte studier ble inkludert for analyse, med tilsammen 388 voksne kirurgiske pasienter i generell anestesi. Alle typer elektiv kirurgi unntatt hjerte- og lungekirurgi ble inkludert. Resultater: Repetert rekrutteringsmanøver etterfulgt av PEEP≥10 cm H2O gav en signifikant bedring i gassutveksling og lungemekanismer. Effekten var størst hos risikopasienter der fedme og laparoskopisk inngrep var en kofaktor. Intervensjonen var godt tolerert med hensyn til faren for hemodynamisk ustabilitet eller barotraume. Konklusjon: Repetert alveolær rekrutteringsmanøver etterfulgt av PEEP≥10 cm H2O bør vurderes som del av en lungebevarende ventilasjonsstrategi hos kirurgiske pasienter i generell anestesi. Konsekvenser for sykepleiepraksis: Anestesisykepleieren bør individualisere bruken av rekrutteringsmanøver og PEEP. Nødvendige tiltak må vurderes og iverksettes for å imøtekomme potensiell risiko, med henblikk på å forebygge postoperative lungekomplikasjoner. Nøkkelord: Generell anestesi, kirurgi, mekanisk ventilasjon, rekrutteringsmanøver, gassutveksling, lungemekanismer, atelektaser. Background: General anesthesia and mechanical ventilation causes collapse of alveolar lung tissue in 85-90 % of all intubated patients. This leads to impaired gas exchange in addition to increased risk of severe post-operative pulmonary complications. A so called lung protective ventilation strategy including recruitment maneuvers is a well-established practice in treatment of ARDS. This strategy is now being proposed to also have potential positive benefits if used in a surgical setting in normal, healthy lungs. Study objective: The aim of this study was to assess the effect of a lung recruitment maneuver in surgical patients during general anesthesia. Method: In this systematic review based on guidelines provided by the Cochrane Collaboration, we analyzed nine randomized controlled studies with a total of 388 patients undertaken between 2005 and February 2016. Systematic searches were performed in Cochrane, Medline, Embase, Cinahl and Scopus databases. All types of elective surgery except heart- or lung surgery were included. Results: A repeated recruitment maneuver followed by PEEP≥10 cm H2O significantly improved gas exchange and lung mechanisms. The gain was highest in risk patients with severe obesity and laparoscopic surgery being cofactors. The intervention was well tolerated in terms of hemodynamics and risk of barotrauma. Conclusion: Repeated recruitment maneuvers followed by PEEP≥10 cm H2O should be included as part of a lung protective ventilation strategy in surgical patients in general anesthesia. Implications for nursing practice: The anesthetic nurse should consider an individualized use of recruitment maneuvers and PEEP, and take the appropriate measures to deal with any potential risks, in order to prevent post-operative pulmonary complications. Keywords: General anesthesia, surgery, mechanical ventilation, recruitment maneuver, gas exchange, lung mechanisms, atelectasis

Effect of alveolar recruitment maneuver during general anesthesia - s sytematic review

Master's thesis in Health and social sciencesBakgrunn: Generell anestesi og mekanisk ventilering fører til kollaps av alveolært lungevev hos 85-90 % av alle intuberte pasienter. Konsekvensene av dette er redusert gassutveksling i tillegg til økt fare for alvorlige postoperative lungekomplikasjoner. Såkalt lungebevarende ventilasjon og rekrutteringsmanøver er en etablert praksis for behandling av ARDS. Nå vurderes det om denne strategien også kan være nyttig for lungefriske under kirurgi og narkose. Målsetting: Målet for dette studiet var å vurdere effekten av en lungerekrutteringsmanøver hos kirurgiske pasienter i generell anestesi. Metode: Vi utførte en systematisk kunnskapsoppsummering basert på retningslinjer fra The Cochrane Collaborate. Systematiske søk ble gjort i databasene Cochrane, Medline, Embase, Cinahl og Scopus fra 2005 til februar 2016. Totalt ni randomiserte kontrollerte studier ble inkludert for analyse, med tilsammen 388 voksne kirurgiske pasienter i generell anestesi. Alle typer elektiv kirurgi unntatt hjerte- og lungekirurgi ble inkludert. Resultater: Repetert rekrutteringsmanøver etterfulgt av PEEP≥10 cm H2O gav en signifikant bedring i gassutveksling og lungemekanismer. Effekten var størst hos risikopasienter der fedme og laparoskopisk inngrep var en kofaktor. Intervensjonen var godt tolerert med hensyn til faren for hemodynamisk ustabilitet eller barotraume. Konklusjon: Repetert alveolær rekrutteringsmanøver etterfulgt av PEEP≥10 cm H2O bør vurderes som del av en lungebevarende ventilasjonsstrategi hos kirurgiske pasienter i generell anestesi. Konsekvenser for sykepleiepraksis: Anestesisykepleieren bør individualisere bruken av rekrutteringsmanøver og PEEP. Nødvendige tiltak må vurderes og iverksettes for å imøtekomme potensiell risiko, med henblikk på å forebygge postoperative lungekomplikasjoner. Nøkkelord: Generell anestesi, kirurgi, mekanisk ventilasjon, rekrutteringsmanøver, gassutveksling, lungemekanismer, atelektaser. Background: General anesthesia and mechanical ventilation causes collapse of alveolar lung tissue in 85-90 % of all intubated patients. This leads to impaired gas exchange in addition to increased risk of severe post-operative pulmonary complications. A so called lung protective ventilation strategy including recruitment maneuvers is a well-established practice in treatment of ARDS. This strategy is now being proposed to also have potential positive benefits if used in a surgical setting in normal, healthy lungs. Study objective: The aim of this study was to assess the effect of a lung recruitment maneuver in surgical patients during general anesthesia. Method: In this systematic review based on guidelines provided by the Cochrane Collaboration, we analyzed nine randomized controlled studies with a total of 388 patients undertaken between 2005 and February 2016. Systematic searches were performed in Cochrane, Medline, Embase, Cinahl and Scopus databases. All types of elective surgery except heart- or lung surgery were included. Results: A repeated recruitment maneuver followed by PEEP≥10 cm H2O significantly improved gas exchange and lung mechanisms. The gain was highest in risk patients with severe obesity and laparoscopic surgery being cofactors. The intervention was well tolerated in terms of hemodynamics and risk of barotrauma. Conclusion: Repeated recruitment maneuvers followed by PEEP≥10 cm H2O should be included as part of a lung protective ventilation strategy in surgical patients in general anesthesia. Implications for nursing practice: The anesthetic nurse should consider an individualized use of recruitment maneuvers and PEEP, and take the appropriate measures to deal with any potential risks, in order to prevent post-operative pulmonary complications. Keywords: General anesthesia, surgery, mechanical ventilation, recruitment maneuver, gas exchange, lung mechanisms, atelectasis

Very-high-frequency oscillations in the main peak of a magnetar giant flare

Magnetars are strongly magnetized, isolated neutron stars1–3 with magnetic fields up to around 1015 gauss, luminosities of approximately 1031–1036 ergs per second and rotation periods of about 0.3–12.0 s. Very energetic giant flares from galactic magnetars (peak luminosities of 1044–1047 ergs per second, lasting approximately 0.1 s) have been detected in hard X-rays and soft γ-rays4, and only one has been detected from outside our galaxy5. During such giant flares, quasi-periodic oscillations (QPOs) with low (less than 150 hertz) and high (greater than 500 hertz) frequencies have been observed6–9, but their statistical significance has been questioned10. High-frequency QPOs have been seen only during the tail phase of the flare9. Here we report the observation of two broad QPOs at approximately 2,132 hertz and 4,250 hertz in the main peak of a giant γ-ray flare11 in the direction of the NGC 253 galaxy12–17, disappearing after 3.5 milliseconds. The flare was detected on 15 April 2020 by the Atmosphere–Space Interactions Monitor instrument18,19 aboard the International Space Station, which was the only instrument that recorded the main burst phase (0.8–3.2 milliseconds) in the full energy range (50 × 103 to 40 × 106 electronvolts) without suffering from saturation effects such as deadtime and pile-up. Along with sudden spectral variations, these extremely high-frequency oscillations in the burst peak are a crucial component that will aid our understanding of magnetar giant flares