DTIC ADA614698: A Novel Means to Classify Response to Resuscitation in the Severely Burned: Derivation of the KMAC Value

0.48 MB·English

by  Defense Technical Information Center

burns 39 (2013) 1060–1066

Available onlineat www.sciencedirect.com

journal homepage: www.elsevier.com/locate/burns

A novel means to classify response to resuscitation

in the severely burned: Derivation of the KMAC

§,§§
value
Joseph F. Kellya, Daniel F. McLaughlina, Jacob H. Oppenheimera,

John W. Simmons IIa, Leopoldo C. Cancioa, Charles E. Wadeb,

Steven E. Wolfc,*

aUnitedStatesArmyInstituteofSurgicalResearch,UnitedStates

bDepartmentofSurgery,UniversityofTexasHealthScienceCenter–Houston,UnitedStates

cDivisionofBurn,Trauma,andCriticalCare,DepartmentofSurgery,UniversityofTexas–SouthwesternMedical

Center,UnitedStates

articl e i nfo ab s tract

Articlehistory: Background: Resuscitationfluidratesfollowingburnarecurrentlyguidedbyaweightand

Accepted21May2013 burnsizeformulae,thentitratedtourineoutput.Traditionally,24hresuscitationisreported

as volume of resuscitation received without direct consideration for the physiologic re-

Keywords: sponse.Weproposeaninput-to-outputratiotodescribethecourseofburnresuscitationand

Burnresuscitation predicteventualoutcomes.

KMAC Methods: WereviewedadmissionstoaburncenterfromJanuary2003throughAugust2006.

Burnmortality Inclusioncriteriawere(cid:2)20%TBSA,admission(cid:3)8hafterburn,andsurvived(cid:2)24h.Demo-

graphics,inputvolumeandurineoutput,andclinicaloutcomeswererecorded.Aratioof

inputvolume(cc/kg/%TBSA/h)tourineoutput(cc/kg/h)wascalculatedat24h.Theratioof

fluidintaketourineoutputreflectingan‘expected’responsewasdeveloped:4cc/kg/%TBSA/

24h (0.166cc/kg/%TBSA/h) divided by 0.5–1.0cc urine/kg/h for an expected range 0.166–

0.334. Subjects were classified based upon the ratio: over-responders (<0.166), expected

(0.166–0.334),orunder-responders(>0.334).Clinicaloutcomeswerecomparedandconcor-

danceofclassificationtovalueswascalculatedat12h.

Results: 102subjectsmetinclusioncriteria;29intheover-responders,37intheexpected,and

36intheunder-responders.Resuscitationvolumewasdirectlyproportionaltothecalculated

ratiowhileurineoutputwasinverselyproportional.Groupmortalitywas21%,11%,and44%,

respectively, with a significant difference between the expected and under-responders

(p<0.002). We found decreased ventilator-free days in the under-responders, and when

deathswereexcluded,decreasedICU-freedaysaswell(p<0.05).Concordanceofpaireddata

gatheredat12hand24hwas67%fortheunder-respondergroup.

Conclusions: We describe a novel ratio to classify acute resuscitation after severe burn

includingthepatient’sresponse.Suchaclassificationisassociatedwitheventualoutcomes.

#2013ElsevierLtdandISBI.Allrightsreserved.

§ PresentedattheAnnualMeetingoftheAmericanBurnAssociation2008.

§§ SupportedbyClinicalTrialsTaskArea–UnitedStatesArmyInstituteofSurgicalResearch,ResearchAreaDirectorateII,UnitedStates

ArmyMedicalResearchandMaterielCommand.

* Correspondingauthorat:UniversityofTexas–SouthwesternMedicalCenter,5323HarryHines,Dallas,TX75390-9158,UnitedStates.

Tel.:[phone];fax:[phone].

E-mailaddress:[email protected](S.E.Wolf).

0305-4179/$36.00#2013ElsevierLtdandISBI.Allrightsreserved.

http://dx.doi.org/10.1016/j.burns.2013.05.016
Report Documentation Page Form Approved
OMB No. 0704-0188
Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information,
including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington
VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it

does not display a currently valid OMB control number.
1. REPORT DATE 2. REPORT TYPE 3. DATES COVERED
01 SEP 2013 N/A -
4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER
A novel means to classify response to resuscitation in the severely burned:
5b. GRANT NUMBER
Derivation of the KMAC value.
5c. PROGRAM ELEMENT NUMBER
6. AUTHOR(S) 5d. PROJECT NUMBER
Kelly J. F., McLaughlin D. F., Oppenheimer J. H., Simmons J. W. 2nd,
5e. TASK NUMBER
Cancio L. C., Wade C. E., Wolf S. E.,
5f. WORK UNIT NUMBER
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION
United States Army Institute of Surgical Research, JBSA Fort Sam REPORT NUMBER
Houston, TX
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S)
11. SPONSOR/MONITOR’S REPORT
NUMBER(S)
12. DISTRIBUTION/AVAILABILITY STATEMENT
Approved for public release, distribution unlimited
13. SUPPLEMENTARY NOTES
14. ABSTRACT
15. SUBJECT TERMS
16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 18. NUMBER 19a. NAME OF
ABSTRACT OF PAGES RESPONSIBLE PERSON

a. REPORT b. ABSTRACT c. THIS PAGE UU 7
unclassified unclassified unclassified
Standard Form 298 (Rev. 8-98)
Prescribed by ANSI Std Z39-18
burns 39 (2013) 1060–1066 1061

Inhalation injury was defined as a history of burn in an
1. Introduction
enclosed space and evidence of upper airway injury on

bronchoscopy. Burnsize and depthweredetermined by the

Initial management of severely burned patients focuses on attending surgeon within 48h of injury. Weight was deter-

resuscitationwithcrystalloidsolutiontorestoreintravascular minedatadmission.

volume. Weight and percent total body surface area burn ResuscitationwasinitiatedwithlactatedRingers’solution

(%TBSA)areusedinvariousformulaetodeterminetheinitial using the Modified Brooke Equation (2cc/kg/%TBSA) or the

intravenousfluidrate[1]andstandardizedchangesinvolume Parkland formula (4cc/kg/% TBSA), and titrated to a urine

infusion. The rate is then commonly titrated hourly to outputof30–50cc/hwithoutparticularprotocol.Albuminuse

maintain a targeted rate of urine output as an indirect was at the discretion of the provider. All intravenous fluid

measureofcardiac output, basedupon volumeper hour,or (crystalloid, colloid, blood products), oral intake (by mouth,

volume/hperbodyweight.Theformulamostcommonlyused nasogastric, or feeding tubes), and urine output was totaled

todayistheParklandformula[2]describedbyBaxterin1968. during the first 24h, including pre-hospital volumes. Blood

Theoriginalstudystatedthatthemajorityofseverelyburned productvolumeswereestimatedbaseduponmeanbloodbank

patients use between 3.7 and 4.3cc of lactated Ringers’/kg/ values;1unitofpackedredbloodcells(PRBC)=350ml,and1

%TBSA to be adequately resuscitated. Since that time, unit of fresh frozen plasma (FFP)=250ml; no other blood

numerous studies have shown that the majority of patients products were administered. Outcomes evaluated were in-

actually receive more than recommended by the Parkland hospitalmortality,abdominalcompartmentsyndrome(ACS),

formula[3–7]. extremity compartment syndrome (ECS), hospital days,

We observed that patients respond differently during ventilator days, and ICU days. Abdominal compartment

resuscitation even when following guidelines, and these syndromewasdeterminedbythosewhounderwentlaparot-

differentialresponsesseemtocorrelatewithpatientoutcome. omywithin48hofadmissioninconjunctionwithmeasured

For example, patients that receive close to the predicted intra-abdominalpressuresover30mmHg.

resuscitationvolumeandmaintainanadequateurineoutput

generallydowell.However,thosewhoreceivelargevolumes 2.2. Ratiocalculation

offluidabovetherecommendedformulaebutremainoliguric

havepooroutcomes.Wesoughttofindamethodtouseduring Theratiowascalculatedbydividingthe24htotalresuscita-

resuscitationtoquantitativelydifferentiatethesepopulations. tionvolume(cc/kg/%TBSA)by24toestablishameanperhour

Thisculminatedinanovelcalculationusingcrystalloidinput volume (cc/kg/%TBSA/h). This was then divided by the 24h

and urine output volume to classify patients into outcome urineoutput(cc/kg/h)togiveaunitlessnumber.Anexample

groups that reflect not only the volume given, but also the ofthecalculationisshown(Fig.1).Standardnormswereused

physiologic responses to the resuscitation volume received to establish reference ranges; 4cc/kg/%TBSA//24h becomes

(Kelly–McLaughlinvalue,i.e.KMAC). 0.166cc/kg/%TBSA/hfortheinputvolume,and0.5–1.0cc/kg/h

asatargetednormativeurineoutputvolumecommonlyused

duringresuscitation,givinganexpectedrange0.166–0.334.

2. Methods The ratio was calculated at 24h with assignment of

subjectsintogroupsabove,within,andbelowthenormative

2.1. Subjects range established above. Comparisons were then made

betweengroups.Then,valuesforthesamesubjectscalculated

AfterInstitutionalReviewBoardapprovaloftheprotocol,we at 12h were paired with correlations and concordance

reviewed all burn unit admissions at our institution from calculated.

January 1, 2003 to August 31, 2006. Criteria used to admit

burnedpatientsintotheburnintensivecareunitwere(cid:2)20% 2.3. Statisticalanalysis

TBSA, inhalation injury, circumferential burns, high voltage

electrical burn injury or as clinically indicated based on the ANOVA with Tukey’s test for multiple comparisons or

assessment of the provider. The inclusion criteria for this Student’s t-test was used to analyze continuous variables.

studywereburnedpatientsweighing(cid:2)40kgadmittedwithin Kruskal–Wallisanalysisbyrankswasusedwhereappropriate.

8hofinjury,>20%TBSAburned,andsurvivedover24h.We Dichotomous variables were compared using x2 or Fisher’s

excluded prisoners, patients admitted to non-ICU beds, exacttest.Regressionswerelinearandpolynomial(3degrees).

electrical injuries, those with other significant traumatic Statisticalsignificancewassetatp<0.05.Valuesarereported

injuries, and those with incomplete pre-hospital data. asmean(cid:4)SEMunlessotherwiseindicated.

4 cc/kg/%TBSA burned (desired resuscitation volume) = 0.167cc/kg/%TBSA per hour

24 hours

0.167cc/kg/%TBSA per hour = 0.167 to 0.333

0.5-1.0 cc/kg/hour

Fig.1–DerivationofKMACvaluesbasedonoptimalresuscitationvolume2dividedbyoptimalurineoutput.
1062 burns 39 (2013) 1060–1066

Pa(cid:2)ents Admi(cid:3)ed

1070
< 20% TBSA

817
> 20% TBSA

253
Died < 24 hours

11
Lived > 24 hours

242
Admi(cid:3)ed > 8 hours
140
Final Cohort
102
Fig.2–CONSORTdiagramforsubjectenrollment.

25
3. Results
A
20
One-hundredtwosubjects,73menand29women,withages

of 42 years(cid:4)1.8 met inclusion criteria for the study (Fig. 2). 15

DemographicdataareshowninTable1.The24hresuscitation n

volume was 5.5(cid:4)0.3cc/kg/%TBSA that approximated a 10

normal distribution with skew to the left (Fig. 3a), urine

output was an average of 74(cid:4)4cc/h or 0.9(cid:4)0.1cc/kg/h
5
(Fig. 3b) with a similar skew to the left. The predicted

resuscitation volume, based on the Parkland formula, was
0
13.6(cid:4)0.7L, while the actual volume was 18.4(cid:4)1.25L
( p < 0. 001 ). 0-1>1-2>2-3>3-4>4-5>5-6>6-7>7-8>8-9>9-10>10-1>111-1>212-1>313-14
Resuscitation Volume (cc/kg/%TBSA burned)
3.1. Ratiogroups

Aftercalculationoftheratioat24h,subjectswereassigned
16
post hoc to respective groups: over-responders (<0.167), B

expected (0.167–0.333), and under-responders (>0.333). Sub- 14

jectswithlowratiovalues(<0.167)hadhigherurineoutputs 12

than targeted relative to fluid infused (over-responsive),
10
expected subjects had the targeted response of 0.5–1.0cc/

kg/h,andsubjectswithhighratiovalues(>0.333)hadlower n 8

urine outputs than targeted in relation to relatively higher 6

4
Table1–Demographicsofthestudypopulation. 2

Gender(%men) 72 0
A%gTeB (SyAea rs) 4420 (cid:4)(cid:4) 12.8 20-3031-4041-5051-6061-7071-8081-9091-101001-111101-112201-113301-114401-1>5 0150
% FT 17 (cid:4) 2 Urine Output in cc/hr

Inhalationinjury(%) 28

In-hospitalmortality(%) 25 Fig.3–(A)Frequencydistributionfor24hresuscitation

24hresuscitation(cc/kg/%TBSA) 5.5(cid:4)0.3 volume(cc/kg/%TBSA);theParklandformularecommends

2244 hh uurriinnee oouuttppuutt ((cccc//hkg) /h) 703.8.59 (cid:4)(cid:4) 30..905 4 cc/kg/%TBSA. (B) Urine output in cc/h for this adult
population;targetrangewas30–50cc.
burns 39 (2013) 1060–1066 1063

Table2–Demographicdataforthethreegroupsdefinedafterratiocalculation.Comparisonsforlowandhighgroupswere

tothedesiredgroup.

Low(n=29) Expected(n=37) High(n=36)

Gender(%men) 83% 73% 61%

Age(years) 40(cid:4)3.1 38(cid:4)2.6 49(cid:4)4*(p=0.02)

%TBSA 38(cid:4)3.2 39(cid:4)2.9 43(cid:4)3.2

%FT 14(cid:4)4.2 13(cid:4)2.9 24(cid:4)4*(p=0.03)

Inhalationinjury(%) 10% 24% 47%(p=0.052)

24hresuscitation(cc/kg/%TBSA) 3.5(cid:4)0.27*(p<0.001) 5.3(cid:4)0.38 7.4(cid:4)0.4*(p<0.001)

24hurineoutput(cc/h) 106(cid:4)7*(p<0.002) 76(cid:4)6 45(cid:4)3*(p<0.001)

24hurineoutput(cc/kg/h) 1.24(cid:4)0.097*(p=0.02) 0.94(cid:4)0.076 0.5(cid:4)0.04*(p<0.001)

volumes, and thus were relatively resistant to resuscitation (p<0.001), but still within the 0.5–1.0cc/kg/h range. Thus,

(under-responsive).Afterthisassignment,29subjectswerein weproposetheseasthe‘under-responders’.Thepercentageof

the over-responder group, 37 in the expected, and 36 in the subjectsinthisgroupwithinhalationinjurywashigherthan

under-respondergroup.Demographicdataforeachgroupare in the expected group, 47% vs 24% which just achieved

showninTable2.Thoseintheunder-respondergroupwere statistical significance (p=0.05). Mortality rate was 4 times

olderwithgreaterfull-thicknessburns(p<0.05).Thediffer- thatofthedesiredgroup,44%vs11%(p=0.002).

enceinburnsize,however,isaccountedforbytheformulaein

theanalyses. 3.5. Performance

3.2. Over-responders(<0.166) Overall, we found no difference in hospital days, ICU-free

days,orabdominalcompartmentsyndromeratesbetweenthe

Thesesubjectshadsignificantlylowerresuscitationvolumes three groups (Table 3). However, we did find the under-

indexed to urine output than the normal group (3.5cc/kg/ responder group had a decrease in ventilator-free days,

%TBSA(cid:4)0.27 vs 5.3cc/kg/TBSA(cid:4)0.38, p<0.001), and a indicatingthatmoreventilatortimeandresourceswereused

significantlyhigheroverallurineoutput(1.24cc/kg/h(cid:4)0.097 forthisgroupcomparedtotheexpectedgroup.Whendeaths

vs 0.94cc/kg/h(cid:4)0.076, p<0.02). For these reasons, we wereexcludedfromallgroups,wefoundthatICU-freedays

propose to call this group the ‘over-responders’ as urine were significantly lower in the under-responder group

output was higher than targeted. They also receivedsignifi- compared to the expected group and over-responder group

cantly less fluid than the other groups. No significant (over-responders 20(cid:4)2 days, expected 17(cid:4)2 days, and

differenceswerefoundinallclinicaloutcomesbetweenthis under-responders 10(cid:4)2 days*) (*p<0.05), indicating that

groupandthose ofthenormalgroup.Outcomedata forthe increasedICUtimewasalsopresentintheunder-responders.

groupsareshowninTable3. Ventilator-freedayswerealsolowerintheunder-responders

comparedtotheothergroups(25(cid:4)1low,22(cid:4)1desired,and

3.3. Expected(0.166–0.334) 15(cid:4)2high*)(*p<0.05).

Thesesubjectsfellwithinthereferencerangesetbymodeling 3.6. Qualification

4cc/kg/%TBSA and 0.5–1.0cc/kg/h for urine output. For this

reason we propose these as ‘expected responders’. All We then performed an analysis whereby the ratio was

comparisonsaremadetothisgroupasthenormalresponse, calculated at 12h for the same subjects and compared to

andthereforeserveascontrols. the 24h value in an effort to show whether the 12h value

predicted the 24h results. A linear regression revealed an

3.4. Under-responders(>0.334) adjustedr2of0.47indicatingmodestcorrelation.Inexamining

thedataclosely,mostofthevarianceappearsinthosestarting

This group had significantly higher resuscitation volumes in the under-responder range (Fig. 4a). To address this

compared to the normal group, 7.4(cid:4)0.4cc/kg/%TBSA vs observation,wespreadthe12and24hdatabyranksfrom1

5.3(cid:4)0.4cc/kg/%TBSA (p<0.001), and a significantly lower (low)to102(high)andrepeatedtheregression.Wefoundthat

urine output, 0.60(cid:4)0.04cc/kg/h vs 0.90(cid:4)0.08cc/kg/h variance is distributed across the range for rank, but the r2

Table3–Outcomedataforthethreegroupsdefinedafterratiocalculation.Comparisonsforthelowandhighgroupswere

tothedesiredgroup(ACS,abdominalcompartmentsyndrome).ICUandventfreedaysarewithinthefirst28days.

Low(n=29) Expected(n=37) High(n=36)

Hospitaldays 31(cid:4)8 43(cid:4)8 44(cid:4)9

ICUfreedays 18(cid:4)2 19(cid:4)3 13(cid:4)2

Ventilatorfreedays 22(cid:4)2 19(cid:4)3 17(cid:4)1*(p<0.05)

ACS(%) 0 5(n=2) 14(n=5)(p=0.26)

Mortality(%) 21 11 44*(p=0.002)
1064 burns 39 (2013) 1060–1066

9 *
40
A
s
8 ur
o
H 30
7 4
2
e n
Valu 6 min i 20
C u
our KMA 45 Grams Alb 10
2 H 3 0
1 Low Desired High
2
Fig.5–Volumeofalbumingiveninthethreegroupsinthe
1
first24hafterinjury.ThegroupwithhighKMACvalues

0 receivedthemostalbumin(*p<0.05).

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

24 Hour KMAC Value

theunder-responders(27/48correct).Ingeneral,thoseatthe

B extremesofthelowandhighrangeat12hstayedwithinthe
100
C groupat24h.
A
M 80 Our final analysis was to determine whether differences
K couldbefoundbetweengroupsontheuseofcolloidsduring
Hour 60 resusc ita tion a nd wheth er this ha d a ny e ffe ct on ou r new
2 ratio. When infused colloid volume in grams was examined,
d 1 40 we found that albumin use and volume was actually highest in
e thehighgroup(Fig.5)perhapsreflectiveoftheprovideruseof
nk
a 20 albumin to treat lack of response to crystalloid during the
R
resuscitationinthisuncontrolledstudy.

0
0 20 40 60 80 100
4. Discussion
Ranked 24 Hour KMAC

Fig.4–Regressionsof12–24hKMACvalues.Thefirst(A)is Since the initial reports of the burn resuscitation formulae

alinearregressionofpaired12and24hdata.Variability [2,3], numerous studies demonstrated that the majority of

increaseswithincreasing24hKMACvalues(r2=0.48).To severelyburnedpatientsreceivemorethanthepredicted4cc/

furtherdemonstratepotentialeffectsatlow24hKMAC kg/%TBSAresuscitationinthefirst24h[4–7].Manyofthese

values,thevalueswererankedfrom1to102andpaired describe qualitative differences in outcomes with high

(B).Inthisanalysis,variabilityseemstobedistributed infusion volumes, however, ideal resuscitation volume and

acrosstherange,butwithhighercorrelation(r2=0.57). how to classify adequacy of resuscitation quantitatively in

Themiddlelineisthelineofregression,andtheoutside relationtoresponseremainundetermined.Inthisstudy,we

linesarepredictionintervals. describeanovelmeansbywhichtoclassifytheresponseto

acuteresuscitationintheseverelyburnedwhichwetermthe

KMAC value. By using resuscitation volume indexed to urine

output, we defined three distinct groups of subjects with

valueimprovedto0.57(Fig.4b).Inparticular,ifthoseabovea differingresponsetoresuscitation;over-responders,normal-

rankof66forthe24hvalueareconsidered,i.e.thoseinthe responders, and under-responders. As expected, the under-

under-responder group, 24 of 36 were above the line of responders received more resuscitation volume, have a

regressionat12h.Therefore,ahigh12hvalue(>0.334)givesa diminished response to such volume, and have poorer

reasonable estimate (67%) of those in the under-responder outcomes.Wefoundutilityinmakingthisdeterminationin

groupat24h.Ofnote,wefoundnocorrelationof24hKMAC thatvaluesdeterminedat24hassigningpersonstotheunder-

valuetoburnsize,indicatingnoindependentassociationto respondergroupassociatedwithpooreroutcomescorrelateto

injuryseverity. paired values at 12h 67% of the time. Therefore, at 12h,

Tofurtherdefinetherelationshipofvaluesat12and24h, relativelyunsuccessfulresuscitativeeffortscanbeidentified

we compared the concordance of values by groups. If the withrelativeconfidenceforthosewithpooreroutcomes,and

subjects are grouped at 12h into the defined ranges, mightindicatefutilityofincreasedintravenousvolumesand

the concordance is 67% for the over-responders staying in rather direct toward other resuscitation adjuncts such as

the assigned group at 24h (22 [24h value]/33 [12h value] colloid use or hemofiltration/plasma exchange. These treat-

correct),42%fortheexpectedgroup(9/21correct),and56%for mentsshouldbetestedinthispopulation.
burns 39 (2013) 1060–1066 1065

The importance of appropriate resuscitation volume adjunctsmightbeconsideredsuchascolloidsolutions,anti-

cannot be overstated. Previous work showed that complica- inflammatory agents, vasoactive medications, or plasma-

tions increase with under [7] and over-resuscitation [8–11]. pheresis/continuous renal replacement therapies without

Unfortunately, the classification of over or under-resuscita- volume removal [13].

tion is sometimes not known until complications occur. Mortality rate was increased in the high KMAC group.

Although burn resuscitation formulae recommending fluid However, these under-responders were older and had

volume infused have stood the test of time in relation to greaterpercentoffullthicknessburns,andbothincreasing

decreasingrenalfailureassociatedwithacuteburns[12],itis ageandburnsizearetraditionalmarkersofburnmortality.

apparentthattheresponsetoinjury,inthiscaseurineoutput, While burn size is accounted for in the ratio which is

foreverypatientandburnsizeisuniqueThus,adifferentbut includedinthecalculations,ageisnot.Nonetheless,thetool

appropriateresuscitationvolumeexistsforeachpatient.Our identifies those with all ages and burn sizes who are not

conclusions are based upon the premise that providers are responding as hoped or expected. This patient group may

striving to maintain urine output while minimizing fluid benefit from adjuncts to traditional resuscitation earlier in

given.Thisisdonewithgreaterskillbysome,whileothersare the course to avoid high volumes of crystalloid and

notdoneaswell.Theratiowhichwedefineinthispapercan resuscitationmorbidity.

beusedasatoolduringresuscitationtodetermineappropriate Interestingly,wefoundthatalbuminuseasacolloidwas

volumes more accurately, but must be anchored by the actuallyhighestinthehighratiogroupintimatingthatthis

relativevolumebeinggivenwithcontinuedeffortstodecrease therapy may not have been as effective as hoped in

fluidsappropriatelyandminimizemorbidityassociatedwith decreasingtotalvolumesinfusedandthesubsequenturine

over-resuscitation(i.e.resuscitationmorbidity).Forinstance, output response. The practice at our unit has been to use

5.0cc/kg/%TBSA is higher than predicted by the Parkland albuminasanadjuncttoresuscitationinthosereceivinghigh

formula,butbelowourmeanresuscitationvolumeof5.5cc/ volumesofcrystalloidandthusalbuminuseinthisgroupwas

kg/%TBSA.Whetherthispatientwasunder,ideally,orover- likelybiasedinthisnon-controlledstudy.However,itmustbe

resuscitatedcannotbedeterminedbyassessmentofintrave- noted that 44% (n=21) of those with a high value at 12h

nousvolumeinfusedalone.Patientresponseofnotonlyurine eventuatedinthenormalgroup.Ofthe48withhighKMAC

output,butalsootherindicatorsofphysiologicequilibriumare valuesat12h,allreceivedalbuminduringtheresuscitation

theultimatetestimonytotheefficacyofresuscitationefforts. after 12h. It could be speculated that albumin treatment

Theadditionofurineoutputintoaratioatleastpartiallytakes contributed to decreasing volumes infused, but this would

thisintoaccount. require a study where some did not receive albumin as

Inderivingtheformula,itshouldbenotedthattheinput controls.

valueincc/kgisdividedbytheoutputvalueincc/kg.Forthe Ofinterest,theunder-respondersalsoconsumedmoreICU

purposesofresuscitationvolumes,weightcanbeconsidered timeandventilatortime.Thesefindingsarethenassociated

as constant, thus in calculating the KMAC value for an with higher volumes received with lower relative urine

individual,weightcanbeomitted.Thus,theformulacanalso outputs.Itispossiblethatthemethodormodeofventilation

be calculated as follows: [volume in (cc)/urine out (cc)]/[% (e.g.beingonamechanicalventilator)leddirectlytochanges

TBSAburned(cid:5)100]. in fluid responsiveness. This should be examined in more

One potential benefit of using this method to assess detail with directed comparison between matched patients

resuscitation is that it can be determined before 24h to with and without mechanical ventilation. Recent evidence

quantitatetheeventualresponse.Whenthe24hvaluewas suggeststhatburnedpatientsaremorecommonlysubjected

compared to a ratio collected at 12h, we found that to mechanical ventilation, sometimes unnecessarily [14],

concordance for the low and normal groups was relatively whichmayinpartexplainhigherresuscitationvolumesseen

strong,andthoseinthehighgrouphadthemostvariation inthecurrentera.

for assignment later in the course. Perhaps this occurred The proposed ratio uses urine output as the marker for

because of routine revisions of fluid delivery upwards in resuscitationadequacy.Whilethisiscertainlythetraditional

response to oliguria more common early in resuscitation methodofassessingresuscitationadequacy,othermeasures

whichresolvesinsome,thus,ahigherKMACvaluemightbe such as blood pressure, peripheral perfusion, and cardiac

expectedinpartofthepopulationthatwilleventuateinthe output when available should also be considered by the

normal range. In addition, perhaps over-resuscitation was provider as output measurements during the course of

detected by the providers with appropriate adjustments in treatment. The ratio, then, should be used as another tool

this non-controlled study to describe some of this diver- in the armamentarium to determine proper treatment. In

gence. Secondly, perhaps internal feedback from increased particular, those with severe inhalation injury may have

fluids induced endogenous shifts that led to functional significantalterationsinfluidphysiologyduetolungchanges

improvement. Non-linear modeling of the response and inadditiontoperipheralchanges;thisshouldcertainlybekept

thus the KMAC over time might shed more light on this inmindduringthecourseofresuscitation.Ultimateutilization

possibility,butisoutsidethescopeofthisstudy.Regardless, of this ratio to determine treatments that might improve

ahighratioat12hclearlyindicatesincreasedriskforlarge outcomesmustbeaddressedinlaterstudies.

volumeresuscitationandincreasedmortalityandincreased Inconclusion,wedescribeanovelcalculationwhichcan

ventilator days and ICU days in survivors. From a clinical beusedduringresuscitationintheseverelyburnedpatients

perspective, the ratio could be collected at 12h to indicate to classify their response. Its use identifies three unique

those likely to continue to be difficult to resuscitate, and groupsamongseverelyburnedpatients.Onespecificgroupof
1066 burns 39 (2013) 1060–1066

patients,theunder-responderswhohadhighKMACvalues, [6] CartottoRC,InnesM,MusgraveMA,GomezM,CooperAB.

are older, have a greater percent of full-thickness burns, and rHeoswus wcietallt idoonevs otlhuem Peasr.kJlaBnudrn foCramreulRae ehsatbimila2t0e0 a2;c2t3u:a2l5 8fl–u6id5.
an increased mortality rate. They might benefit from
[7] ChungKK,WolfSE,CancioLC,AlvaradoR,JonesJA,
adjunctivetherapiestothetraditionalcrystalloidresuscita-
McCorcleJ,etal.Resuscitationofseverelyburnedmilitary
tion. Further investigation as to the clinical utility of using the casualties : flu id b egets more flu id . J Traum a 2009;6 7:231–7.
KMACratioiswarranted[15]. [8] EngravLH,ColescottPL,KemalyanN.Abiopsyoftheuseof

theBaxterformulatoresuscitateburnsordowedoitlike

Charliedidit?JBurnCareRehabil2000;21:91–5.

Conflict of interest statement [9] IvyME,AtwehNA,PalmerJ,PossentiPP,PineauM,D’Aiuto

M.Intra-abdominalhypertensionandabdominal

compartmentsyndromeinburnpatients.JTrauma
None.
2000;49:387–91.
[10] SheridanRL,TompkinsRG,McManusWF,PruittBA.

references Intracompartmental sepsis in burn patients. J Trauma
1994;36:301–5.
[11] ZakAL,HarringtonDT,BarilloDJ,LawlorDF,ShiraniKZ,

GoodwinCW.Acuterespiratoryfailurethatcomplicates

[1] AlvaradoR,ChungKK,CancioLC,WolfSE.Burn theresuscitationofpediatricpatientswithscaldinjuries.J

resuscitation.Burns2009;35:4–14. BurnCareRehabil1999;20:391–9.

[2] BaxterCR.Physiologicalresponsetocrystalloid [12] PruittBA.Protectionfromexcessiveresuscitation:

resuscitationofsevereburns.AnnNYAcadSci ‘‘pushingthependulumback’’.JTrauma2000;49:567–8.

1968;150:874–83. [13] ChungKK,JuncosLA,WolfSE,MannEE,RenzEM,White

[3] PruittBA,MasonAD,MoncriefJA.Hemodynamicchanges CE,etal.Continuousrenalreplacementtherapyimproves

intheearlypost-burnpatient:theinfluenceoffluid survivalinseverelyburnedmilitarycasualtieswithacute

administrationandofavasodilator(hydralazine).JTrauma kidneyinjury.JTrauma2008;64:S179–87.

1971;11:36–46. [14] MackieDP,vanDehnF,KnapeP,BreederveldRS,BoerC.

[4] KleinMB,HaydenD,ElsonC,NathensAB,GamelliRL, Increaseinearlymechanicalventilationinburnpatients:

GibranNS,etal.Theassociationbetweenfluid aneffectofcurrentemergencytraumamanagement?J

administrationandoutcomefollowingmajorburn–a Trauma2011;70(3):611–5.

multicenterstudy.AnnSurg2007;245:622–8. [15] LawrenceA,FaraklasI,WatkinsH,AllenA,CochranA,

[5] CancioLC,ChavezS,Alvarado-OrtegaM,BarilloDJ,Walker MorrisS,etal.Colloidadministrationnormalizes

SC,McManusAT,etal.Predictingincreasedfluid resuscitationratioandameliorates‘‘fluidcreep’’.JBurn

requirementsduringtheresuscitationofthermallyinjured CareRes2010;31:40–7.

patients.JTrauma2004;56:404–13.