112 LETTERSTOTHEEDITOR DominiquePrata,PierreTrouillera,BenjaminSztrymfa,b,∗
aUniversitéParisSud,HôpitalAntoineBéclère, Réanimationpolyvalenteetsurveillancecontinue, Clamart,France
bCentreHospitalierMarieLannelongue,LePlessis Robinson,France
∗Correspondingauthor.
E-mail:benjamin.sztrymf@aphp.fr(B.Sztrymf). Availableonline9June2017
https://doi.org/10.1016/j.bjane.2017.01.007 0034-7094/
©2017PublishedbyElsevierEditoraLtda.onbehalfofSociedade BrasileiradeAnestesiologia.Thisisanopenaccessarticleunder theCCBY-NC-NDlicense(http://creativecommons.org/licenses/ by-nc-nd/4.0/).
Systemic
stress
and
PEEP
relationships
during
laparoscopic
cholecystectomy:
a
new
protective
marker?
Estresse
sistêmico
e
sua
relac
¸ão
com
PEEP
durante
colecistectomia
laparoscópica:
um
novo
marcador
protetor?
DearEditor,
Theinteractionof Positive End-ExpiratoryPressure (PEEP) effects in gas exchange and lung mechanics during Mechanical Ventilation (MV) in intra and postoperative abdominalsurgeryaregloballywellknown.1However,
dur-ing laparoscopic cholecystectomy they remain untested. We have read with great interest the study by Oznur et al., on which they move forward testing the PEEP effectsduringlaparoscopic cholecystectomyintwogroups regarding tothe PEEP level applied(5---10cm H2O). They
registered hemodynamic (cardiac rate/systolic---diastolic pressure/meanarterialpressure),respiratory(arterial oxy-gen saturation/partial pressure of carbon dioxide at the end of expiration (ETCO2), and metabolic
parame-ters(glucose/insulin/cortisol/lactic),alongthreedifferent treatmentstages(before/duringandafterthesurgery).The resultsshowedaclear benefitoncomplianceand oxygen-ation,a reduction on post-surgicalstress, and everything without hemodynamic norrespiratory deleteriouseffects, whenhigherpeeplevelswereset.HigherPEEPlevelsrecruit thelung,raisingthecomplianceandimprovingthe oxygen-ation,it also reduces the ventilation/perfusion mismatch and hence limiting the respiratory shunt.1 On the
hemo-dynamic point of view, the positive pressure on the lung mechanicsrisestheleftcardiacoutputmainlythroughthe after load reduction, but also reduces the right cardiac outputdue totheright afterloadelevation; sowhenthe patient’shydratationlevelisadequate, theglobalcardiac performance improves. As a final result, the physiologic stresssecondarytoacertainclinicalcondition,islimited, duetothesecuredperipheraltissueoxygenation,andhence cortisolandlacticlevelsdecline2asshownbyauthors.
Firstly, protective effects of PEEP need to be address in time. We know that abdominal condition and their derivedsurgicalprocedures,whenneeded,intra-abdominal
pressure(Pabd)peaks,decreasingthelungcompliance,and leadingtoacollapseonthelowerpulmonarylobesalveoli. Theatelectasisde-recruitsthelung,droppingdramatically the FunctionalResidual Capacity(FRC)and worseningthe pulmonaryshuntandsotheoxygenationandtheCO2wash
out.Previouslypapers,Pankajetal.3hadalreadyconcluded
the same effect as Oznur et al., but not long-term out-comeonstress(60minafterextubation),yetobserveduntil thisstudy.In ouropinionassociations between postopera-tivepulmonarycomplicationsandtheprotectivestressuse ofPEEPneedtobeclarified.Wedonothavethiskeypoint andmainlypulmonarypost-surgicalcomplications(earlyor late)needalsotobetakenintoaccount.
Secondly,associationsofintrabdominalpressureandthe intrathoracic pressure is a controversial determinant for postoperatorypulmonarycomplications.Neverthelesssome studies4 didnotreportedanstraightrelation betweenthe
raise onthe intrabdominal pressureand the intrathoracic pressure on patients undergoing laparoscopy surgery. On the other hand, there arealso the severe pathophysiolo-gicaleffectsoccurringnotonlyonthelung,butalsoonthe liver,kidneyandheart,whichpotentiallyleadto cardiore-nal, hepatopulmonary or hepatorenal syndromes.5 Higher
peep,cautiouslyused,canfightbackthosedeleterious con-ditions throughthe oxygenation and cardiac performance improvement.
Thirdly,sensibilityandspecificofvariablesusedtodefine ‘‘physiologicstress’’arelimitedforotherdeterminants fac-torsduringsurgeryprocedure (tissueoxygenation,cortisol andlacticlevels).Additionally,nopreviouspathological con-ditions existed ontheselectedpatients,sonot chanceto know if the outcomes on stress respond would be repro-ducible on patients with diabetes, cardiac, endocrine or respiratorydisease.
Fourthly, PEEP levelsshouldn’t be staticbut dynamic, duetheconstantchangingclinicalcondition,noteven dur-ing short time period and minimal invasive surgery, as laparoscopy,becauseofthealteredintrabdominalpressure whilesurgicalproceduresaredelivered.Theclinicianmust findtheproperpeeplevelaccordingtothegeneral condi-tion, the surgical timing and of course the hemodynamic state, duetothepositivepressureeffectsonthepatients hemodynamics.6
LETTERSTOTHEEDITOR 113
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
References
1.Barbosa FT, Castro AA, de Sousa-Rodrigues CF. Positive End-Expiratory Pressure (PEEP) during anesthesia for prevention of mortality and postoperative pulmonary complications. Cochrane DatabaseSyst Rev.2014;6:CD007922, http://dx.doi.org/10.1002/14651858.CD007922.pub3.
2.SenO,DoventasYE.Effectsofdifferentlevelsofend-expiratory
pressureonhemodynamic,respiratorymechanicsand systemic
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Anestesiol.2017;67:28---34.
3.Kundra P, Subramani Y, RavishankarM, SistlaSC, Nagappa M,
Sivashanmugam T. Cardiorespiratoryeffects ofbalancingPEEP
withintra-abdominalpressuresduringlaparoscopic
cholecystec-tomy.SurgLaparoscEndoscPercutanTech.2014;24:232---9.
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esophageal and abdominal pressures in mechanically
venti-lated patients undergoing laparoscopic surgery. Respir Care.
2014;59:491---6.
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Inten-siveTher.2014;46:433---50.
6.EsquinasAM.Noninvasivemechanicalventilation:theory,
equip-ment,andclinicalapplications.Springer;2015.
JacoboBacarizaBlancoa,∗,AntonioM.Esquinasb
aHospitalGarciaDeOrtaEmpresaspublicasempresarias, UnidadedeTerapiaIntensiva,Almada,Portugal
bHospitalMeseguer,UnidadedeTerapiaIntensiva,Murcia, Spain
∗Correspondingauthor.
E-mail:jacobobacariza@hotmail.com(J.B.Blanco). Availableonline7June2017
https://doi.org/10.1016/j.bjane.2017.01.008 0034-7094/
