b'With Video Series, USU Breathes Life Into Ventilator Training for COVID-19perfusionratio,lowlungweightandfrom the ARDSNet protocol developedown complications, including bleeding low recruitability. 3 for classic ARDS.and stroke. The equipment is also not About 30% of patients progress to theThethoughtisthatchangingven- widely available. Tier H phenotype of COVID-19 ARDS,tilatorstrategiesmightkeepmoreAnotheroptionisairwaypressure which more closely resembles conven- patients from progressing to the morerelease ventilation (APRV). APRV is a tionalARDS.TypeHpatientshavesevere manifestations of the syndrome.ventilatorymodethatusesfairlyhigh high elastance, high right-to-left shunt,Suggestedstrategiesincludeusingand sustained continuous positive pres-high lung weight and high lung recruit- nasalcannulaorcontinuouspositivesure,combinedwithashortrelease ability, according to Gattinoni. airwaypressure(CPAP)orbilevelphasethatpermitscarbondioxide Muchremainsunknownaboutthepositiveairwaypressuremachinesremoval.APRVallowsthepatientto pathophysiologyandprogressionforpatientswhorespondtooxygenbreathespontaneouslythroughoutres-ofrespiratoryfailureinCOVID-19.therapy and do not require intubation,piration,independentoftheventilator Patients may deteriorate, moving fromalthough the latter two options increasecycle. TypeLto TypeH,asaresultofantheriskofaerosolizationofparticlesSofar,wehavehadconsiderable interplayoftheviralinfectionitself,and spread of infection. successwithAPRVinourCOVID the immune response to the infection,Others have found that changing thepatients,saidJoshFarkas,MD,a hemodynamic factors and lung injuryventilation approach even for patientscriticalcareandpulmonarydisease from ventilation. withmoreseverelunginjurycanphysician,assistantprofessoratthe Becauseofthedifferencesbetweenincreasesurvivability.ExtracorporealUniversity of Vermont Medical Center Lphenotypepatientsorthehappymembraneoxygenation(ECMO)hasinBurlington,VT,andeditorofthe hypoxics and patients with more tra- beenusedinsomeinstances.ECMOPulmcrit blog. This has allowed us to ditional presentations of ARDS, a num- oxygenatesbloodoutsidethebody,supportandextubateseveralpatients ber of experts in the field have recom- reducing stress on lungs. ECMO is ansuccessfully, while avoiding paralysis, mendedusingtherapiesthatdivergeexpensive procedure, however, with itsproning, deep sedation, inhaled pulmo-nary vasodilators, or ECMO.UsingAPRVastheinitialventila-tor mode rather than as salvage might bemostuseful,henoted.Typically patients find APRV more comfortable, so they require fewer medications. Patientstypicallycanbeweaned from 100% FiO2 to 50% FiO2 on APRV within six to 12 hours as they slowly recruit,henoted,thoughthosethat do not respond within 12 to 24 hours should be moved to prone ventilation.1ICNARC. ICNARC report on COVID-19 in critical care.29 May 2020. 2Marini JJ. Dealing with the CARDS of COVID-19. Critical Care Medicine. May 13, 2020. Online first. DOI: 10.1097/CCM.00000000000044273Gattinoni L. et al. COVID-19 pneumonia: different respiratory treatment for different Col. Karin Nicholson is positioned inside the Carl R. Darnall Army Medical Centers new rotating bed during anphenotypes? Intensive Care Medicine. 2020 intensive care unit staff training session. Prone positioning therapy is one of the newest techniques being usedDOI: 10.1007/s00134-020-06033-2in the intensive care unitimprove outcomes for patients with acute respiratory distress syndrome.Army photo by Mikaela Cade2020 COMPENDIUM OF FEDERAL MEDICINE 53'