An intervention study in the intensive care unit

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Availableonlineatwww.sciencedirect.com

ScienceDirect

j ou rn a l h o m e p a g e :w w w . e l s e v i e r . c o m / i c c n

Lighting,

sleep

and

circadian

rhythm:

An

intervention

study

in

the

intensive

care

unit

Marie

Engwall

a,∗

,

Isabell

Fridh

a

,

Lotta

Johansson

b

,

Ingegerd

Bergbom

a,b

,

Berit

Lindahl

a

a_Faculty_of_Caring_Sciences,_Work_Life_&_Social_Welfare,_University_of_Borås,_SE-501₉₀_Borås,_Sweden b_Institute_of_Health_and_Care_Sciences_at_the_Sahlgrenska_Academy,_University_of_Gothenburg,_Box_457,_SE

40530Gothenburg,Sweden

Accepted4July2015

KEYWORDS

Circadianrhythm; Criticalcare; Contentanalysis; Cycledlight; Intensivecareunit; Interview;

Mann—Whitney-test; Lighting;

Nursing; Sleep

Summary Patientsinanintensivecareunit(ICU)mayriskdisruptionoftheircircadianrhythm. InaninterventionresearchprojectacycledlightingsystemwassetupinanICUroomtosupport patients’circadianrhythm.PartIaimedtocompareexperiencesofthelightingenvironment intworoomswithdifferentlightingenvironmentsbylightingexperiencesquestionnaire.The resultsindicateddifferencesinadvantageforthepatientsintheinterventionroom(n=48),in perceptionofdaytimebrightness(p=0.004).Innighttime,greaterlightingvariation(p=0.005) was foundintheordinaryroom(n=52).Part IIaimedtodescribeexperiences oflightingin theroomequippedwiththecycledlightingenvironment. Patients(n=19)were interviewed andtheresultswerepresentedincategories:‘‘Adynamiclightingenvironment’’,‘‘Impactof lightingonpatients’sleep’’,‘‘Theimpact oflighting/lightsoncircadianrhythm’’and‘‘The lightingcalms’’. Most hadexperiences fromsleepdisordersand halfhadnightmares/sights andcircadianrhythmdisruption.Nearlyallwerepleasedwiththecycledlightingenvironment, whichtogetherwithdaylightsupportedtheircircadianrhythm.Innight’sactuallightinglevels helpedpatientsandstafftoconnectwhichengenderedfeelingsofcalm.

∗_{Corresponding}_author._Tel.:₊₄₆_733787377.

E-mailaddresses:[email protected](M.Engwall),[email protected](I.Fridh),[email protected](L.Johansson), [email protected](I.Bergbom),[email protected](B.Lindahl).

http://dx.doi.org/10.1016/j.iccn.2015.07.001

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ImplicationsforClinicalPractice

• Mostpatients areawareof the lighting environment,indicating the importanceof adapting lighting topatients’

preferences.

• Lightandlightingwhichfollowanaturalrhythmsupportpatients’circadianrhythm.

• Lightingexperiencesarehighlyindividual.Lightatnightcanbebothdisturbingandprovideafeelingofsecurity.

Background

Thisstudyfocusesonpatients’experiencesandreportsof beingcaredforinanintensivecareunit(ICU)patientroom, providedwith a cycled lighting intervention that aims to supportthepatients’circadianrhythmandhealth.The cir-cadianrhythmisconstitutedofregulardayandnightover approximately24hoursandlightanddarknessisimportant for the human health in supporting the body’s circadian rhythm(Gaggionietal.,2014;LeGatesetal.,2014).Asearly as1912Nightingaledescribedlightandtherhythmofnight anddayastwoimportantfactorsinsupportingandrestoring patient health. Sleep and wakefulness is the most obvi-ouscircadianrhythminhumans(GermainandKupfer,2008) andbothstateshavebeendescribedasbasichumanneeds by Henderson (1966). The circadian rhythms are driven bythe circadian pacemaker in the anteriorhypothalamus whichfunctions asthe person’sinner clock (Saperetal., 2004).Exogenousstimuli suchaslightareable tosetthe circadianrhythm inmotion (Veitchetal.,2004). Further-more,lightstimulatestheimmunesystembyregulatingthe pinealneurohormone melatonin(Maestroni,2001),it initi-atestheabsorptionofVitaminD(Masonetal.,2011)andhas beenreportedtoreducethenumberofdaysinhospitalfor patientswithbipolardepression(Benedettietal.,2001).

It is also important to emphasise that light, circadian rhythmandsleepareinterrelatedandinterdependent(Dijk and Archer, 2009). The presence of nighttime light sup-pressesthe melatonin level, which is normally highest at night(Duffy and Wright, 2005). The level of melatonin is widely accepted as an indicator for the circadian rhythm (Benloucif et al., 2005). There are indications that the constantvariationsincircadianrhythms,duetothe

chang-ing hormone levels, experienced by night workers have

increasedtheriskofcancer,aswellasinfectiousand autoim-munediseases(Lockleyetal.,2003).

Criticallyillness,lightandcircadianrhythm

Asthemostcriticallyillandvulnerablepatientsarecared for in the ICU it is most important for their survival and health that the environment supports patient restorative processes.Unfortunatelytheordinaryindoorlight environ-ment in ICUs does not always support patients’ circadian rhythms.Lightingissometimesusedathighlevelsatnight, duringtreatments,examinationsandnursingactivitiesand thismayriskdisruptingthecircadianrhythm(Dunnetal., 2010). Mean illumination levels measured in four differ-ent ICUs ranged at night from 2.4 to 145lx and in the day from55.3 to165lx (Dennisetal., 2010; Frisk etal., 2004;Meriläinenetal.,2010;Vercelesetal.,2012).These

measurements highlight two main problems, a pattern of lowilluminationlevelsbydayandhighlevelsbynight.

TheICUpatients’nighttimesleepisdescribedas

abnor-mal and fragmented with reduced periods of REM sleep

(Elliottetal., 2013).Light inthe nightis oneknown fac-torforsleepdisruptionwhenitimpairsmelatoninsecretion (Kamdar et al., 2012). Circadian rhythms are temporally

disturbed in most ICU patients; some develop temporal

disorganisation andthe circadian pacemakermay become effectivelyfree-running(Frisketal.,2004;Gehlbachetal., 2012;Perras etal.,2007).Furthermore,sleepdeprivation isoneimportantriskfactorforICUdelirium(Girardetal., 2008). Patients’ vulnerability increases withlack of sleep andarecharacterisedbyincreasedsensitivitytolight,noise andactivity(McKinleyetal.,2002).The health,wellbeing andrecovery ofpatients aredependent upontheir ability togetanormalsleepandcircadianrhythm.Mostresearch into light environments affecting the circadian rhythm in anICUcontexthasbeen donewithinfants(Engwalletal., 2014; Moragand Ohlsson,2011).Based onthe knowledge concerninglightanditsimportancetothecircadianrhythm itwouldseemimportanttomeasureandthenevaluateand reportpatients’experiences.

Aims

This study consisted of two parts: in Part I, the aim was to evaluate and compare patients’ experiences of light-ingenvironmentsin twoICU rooms withdifferent lighting environments;inPartII,theaimwastodescribepatients’ experiencesofanICUroomequippedwithacycledlighting environment.

Method

This studywasapartofalargerstudyconcerningpatient experiences ofthe ICUenvironment withregardtosleep, restandcircadianrhythms(Engwalletal.,2014;Johansson etal., 2012). Part Iwasa comparative,descriptive study whichincludeddatafromaquestionnaireusedtocompare twopatient groups, oneexposed toa cycled lighting sys-tem and the other to an ordinary lighting system. Part II had an explorative and descriptive design based on data derivedfromnineteeninterviews,subjectedtoqualitative andquantitativecontentanalysis(Krippendorff,2004).

Setting

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Table1 Scheduleconcerning14 differentlightscenesin periods and illumination levels in the intervention room. IlluminationlevelinluxmeasuredinJanuary2012.

Lightscenes

healthwasinstalledandusedinamodifiedtwo-bedpatient room (intervention room). An identical two-bed patient roomwasleftuntouchedforcomparison(ordinaryroom).

In the interventionroom, acycledlighting system was developed in cooperation with an expert in environmen-tal psychology andlightingengineers. The lightingsystem aimed to simulate natural light regarding localisation, brightnessandcoloursoflight,workedin14differentlight scenesthatwere allcontrolledautomaticallyby software roundtheclock.Thelightsourceswerelocatedatfloorlevel andonwallsandalightfitmentprovidingindirectlighthung down45cmfromtheceiling,shiningupwardinordernotto blindthepatient.Thecolouroflightvariedintwo differ-enttubes(2700Kand6500K)shiningfromthelightfitment. The day lighting lasted from 07.00 to19.00hours.In the morning,awarm,low-levellightstartedthedayandwith a continued brighter morning period that aimed towake and alert the patients. At noon the levels became lower anddaylightshonethroughthewindows.Inthe afternoon thelightinglevelswerehigheragainandintheeveningthe samewarmcolourandlow-levellightingasinthemorning wasrepeated.By night,light levels wereevenlower and

Table2 Lightsettingsinilluminationlevelsintheordinary room.IlluminationlevelinluxmeasuredinJanuary2012.

Differentlight sourcesin comparisonroom

Illuminationlevelsinlux inhorizontalplaneatthe patientsheadinJanuary

onlythelight sourcesnear thefloorwere used.The staff thenusedlocalisedlightingforworkwhennecessary.Inthe two-bedordinaryroomwhichwasusedasacontrolthelight sourceshadbeen installedin1992 andthe staffswitched thelight onand off manuallyaccording totheir ownand thepatients’preferences.Bothroomsfeaturednorth-facing windowswhichletindaylightandprovidedaviewofagrassy slopeaswellasasmallglimpseofthesky.Lightlevelswere measuredateachlightsettingintheinterventionroomand ateachlight sourceinthe ordinaryroom(Tables1and2, Engwalletal.,2014).

Participants

and

procedure

Patients,whowereadmittedtotheICU,wereassignedto one of the two rooms according to patient flow. If beds inbothroomswereavailable, patientswereassigned ran-domly. In some cases, the patient’s health condition and special needs aswell as the number of staff determined whichroomthepatientwasallocatedto(Fig.1).

Inclusioncriteriaforcompletingthequestionnaire(Part I)werecompetenceinthe Swedishlanguageanda stable health condition. Exclusion criteria were the presence of psychosis,dementia,blindness,heavybraininjuriesor test-ing positive on Confusion Assessment Method for the ICU (CAM-ICU).DemographicdataispresentedinTable3.

Inclusioncriteriaforparticipatingintheinterviewstudy (PartII)wereplacementintheinterventionroomforatleast twonights,competenceintheSwedishlanguage,abilityto rememberthepreviousnightsandbeinghealthyenoughto copewithaninterview.Exclusioncriteriawerethesameas describedabove.Thefirstauthorvisitedthepatientsinthe ICUorshortlyafterdischargeinthegeneralward.Patients healthy enough to copewith an interviewwere asked to participate.Atotalof19patientstookpart;twodeclined participation(Table4).Twelveofthe19patientsboth par-ticipatedintheinterviewsandansweredthequestionnaire. Sevenofthe19patientswereonlyabletoparticipateinthe interviews,conductedafterdischargefromtheICU. Their poorhealthsituationpreventedthemfromcompletingthe questionnaire(Fig.1).

Duringtheperiodofdatacollectionaprotocolwas com-pleted,includingallpatientsadmittedtooneofthetwo-bed rooms.Excludedandincludedpatients,demographics,type ofdatacollection, placeandperiodofcare, deaths, con-sentand dischargewere allnoted.Therewere significant differences(Table5)betweenpatientsincludedinthestudy andthosewhowereexcludedinrelationtoSimplifiedAcute PhysiologyScore(SAPS)andnumbersofmechanically venti-latedpatients.

Data

collection

Part I comprises data collected by means of a

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at the ICU, from August 2012 to May 2014.

Missed due to nights, weekends and holidays (n=99).

Excluded due to inclusions criterias (n=60).

Deaths (n=12).

No signed agreement (n=7).

in part II. 7

12

Figure1 Flowchartofpatientselection,PartsIandII.

Table3 Demographic data (numbers ofpatients, age,sex, SAPSandmechanically ventilation) andcomparisons between

patientsintheinterventionandtheordinaryroom,inthedayandnight,PartI.

Patientsinthe intervention group,day

Patientsin theordinary group,day

p-Value, day,t-test. Significant value,<0.05

Patientsinthe intervention group,night

Patientsinthe ordinarygroup, night

p-Value,night, t-test.Significant value,<0.05

n 45 50 17 13

Ageinyear,mean 60 62 0.491 63 64 0.844

Genderratio, men(n)

24 25 0.838 12 10 1.000

SAPSscore,mean 51.07 47.74 0.345 52.47 53.46 0.819

Mechanically ventilated(n)a

25 23 0.413 10 6 0.713

a_Number_of_patients_using_invasive_or_noninvasive_ventilation.

Thequestionnairewasusedtocomparepatients’ experi-enceofthelightenvironmentintheinterventionwiththat in theordinary room. Reliabilitywastested and revealed fourorthogonalcomponentsnamed; hedonictone, bright-ness,variationandflicker.Thequestionnairehaspreviously beenusedinresearchwithhealthypeople(KüllerandLaike, 1998).

Theassessmentofthelightenvironmentwasperformed inthepatient’sroomattheendoftheirstayintheICUor whentheywereabletoparticipate.Thequestionnairewas administeredbynursingorresearchstaffandcompletedby

Table4 Demographic data(numberofpatients,sex and

age,mechanicallyventilated),PartII.

Patientsinthe interventionroom

n 19

Ageinyear,mean 65

Genderratio,men(n) 13 Mechanicallyventilated(n)a ₁₆

a_Number_of_patients_using_invasive_or_noninvasive_ventilation.

thepatients.Sometimesthepatientswerehelpedwiththe writing.Thequestionnairetookaboutfivetotenminutesto complete.ThedatawerecollectedfromAugust2012until May2014.

In Part II, semi-structured interviews supported by an interviewguidewereusedtogainadeeperunderstanding of the patients’ experienceof the light environment and circadianrhythm(Fig.3).Interviewswereconducted imme-diately prior toor after patients’ discharge fromthe ICU tothegeneralwardandvariedinlengthfromfivetoforty minutesdependingonthepatients’experiencesandhealth. Theinterviewswererecordedandtranscribed.Onlypatients fromtheinterventionroomwereincludedintheanalysisas theresearchers’wereinterestedinpatientexperiencesof thecycledlightingenvironment.Theseinterviewswere con-ductedinJanuary2013andfromSeptember2013untilApril 2014. The patientsweredrawn fromthedataset (n=194) and(n=100)basedoninclusioncriteria(Fig.1).

Analysis

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Table5 Demographicdata(numbersofpatients,age,sex,SimplifiedAcutePhysiologyScore(SAPS)andmechanicalventilation) comparisonsbetweenincludedandexcludedpatients,PartI.

Patientsinthe inclusiongroup

Patientsinthe excludedgroup

p-Value,t-test. Significantvalue,<0.05

n 100 281

Ageinyear,mean 61 60 0.431

Genderratio,men(n) 52 168 0.195

SAPSscore,mean 49.40 55.19 0.011

Mechanicallyventilated(n)a ₅₀ ₁₉₃ _0.001

a _Number_of_patients_using_invasive_or_noninvasive_ventilation.

How do you experience the light in this room?

Select by ticking the following scale:

Dark Light

Figure2 Anexampleofanitemfromthequestionnaire,Part I.

theMann—Whitneytesttocomparepatients’lighting expe-riencesbetweenthetworooms,bothbydayandatnight.

The interview data in Part II, were subjected to both quantitative (Krippendorff, 2004) and qualitative conven-tional(HsiehandShannon,2005)contentanalysis,focusing onthetext’ssubjectivecontent.

Thetranscriptswerereadseveraltimes;wholenesswas soughtandmeaningfulconceptsnoted.Codeswerecreated whichdescribedsmallpartsofthecontentoftheinterviews.

The codes were then assembled in one document andby

identifyingandcomparingsimilaritiesinthecodestheywere putintodifferentclusterslinkedtoeachotherbycontent. These clustersformedsubcategories which described sim-ilarcontentandwerethen organisedintocategories.This processwascreatedinductivelyandkeptclosetothe trans-cripts to ensure credibility. There was a quantifying part

in the analysis process asfive questions in the interview guidecouldbeansweredwithyesorno.Theseresultsare presentedseparately.

Ethical

considerations

EthicalapprovalwasgivenbytheRegionalUniversityEthics ResearchCommittee(no695-10).TheHelsinki declaration ofEthicalPrinciples forMedicalResearchinvolving human subjectsguidedthestudy(WorldMedicalAssociation,2013). Patientsreceivedbothverbalandwritten informationand wereinformedoftheirrightsasvoluntaryparticipantsprior toprovidingwritten consenttoparticipationinthe study. Patientswereaskedtoparticipatewhentheirhealth situ-ationwasstable:atthebeginning,middle orend oftheir stay.Researchersevaluatedthepatients’abilityto partic-ipateregardingtheirhealthsituationincollaborationwith theICUheadandtheallocatednurse.Patientsweretreated sensitively and the data collection was ended if patients wereunabletocompletequestionnairesorinterviews.Every dayintheperiodofdatacollectiononeoftheresearchers wasresponsiblefor the processat theICU. Patientswere admittedto the ICU around the clock and were asked to participateassoonasitwaspossible.

1. How have you been sleeping in this room during the nights here in the ICU? 2. How has it been for you to fall asleep?

3. Have you been afraid to go to sleep? 4. Have you woken up during the night? 5. What or who woke you up?

6. Do you remember anything that happened during the nights here in the ICU? 7. What feeling do you get when you think of the nights here in the ICU? 8. Have you had any dreams or visions?.

9. What help did you get to sleep?

10. Did you sleep here in the room during the day? 11. What was sleep during the day like?

12. Did you feel rested during the day? 13. How do you sleep at home?

14. How have you kept track of the time during the day?

15. How have you been able to keep track of the morning, afternoon, evening and night? 16. How have you distinguished between day/night?

17. What time of day is it now?

18. What do/did you think about the lighting in the room? 19. Did the light vary during the day? If yes, describe how.

20. What did you think of the brightness at night? Did the light disturb your sleep? 21. Was it light enough for you to feel safe during the night?

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Table6 Patients’assessmentofthelightenvironment,PartI.

Factor Intervention room,day

Ordinaryroom, day

Mann—Whitney-test

Intervention room,night

Ordinary room,night

Mann—Whitney-test

Mean Mean p-Values

significant p-value,<0.05

Mean Mean p-Values

significant p-value,<0.05

Hedonictone 5.18 4.94 0.280 5.28 5.01 0.166

Brightness 4.75 4.07 0.004 3.84 3.73 0.619

Variation 3.95 4.00 0.564 3.50 4.58 0.005

Colour 3.65 3.22 0.325 3.40 3.64 0.753

Flicker 2.26 1.94 0.415 2.15 2.55 0.128

Table7 Patients’experiencesofsleep,nightmares/visions,circadianrhythmandpleasedwiththecycledlightingenvironment,

PartII.

Participants Sleptbadly intheICU

Sleptbadly athome

Experiencesof nightmaresor/and illusions

Experiencesof disturbedcircadian rhythm

Pleasedwiththe cycledlighting environment

N=19 11/18a _4/17b _9/19 _9/19 _16/17b

a_One_patient_missing. b _Two_patients_missing.

Results

Theresultsfromthequestionnaire(PartI)arepresentedin textandinTable6.

Lightingexperiences,PartI

Thequestionnaireinvolved100patients(Fig.1)caredforin oneofthetworoomswhocompletedatotalof95 assess-ments in the daytime and 30 at night; i.e. 25 patients completed assessments for both day and night. A signifi-cant differencewasfound between lighting environments inthetworooms’forbrightness(p=0.004)inthedaytime, favouringtheinterventionroom.Therewasasignificant dif-ference(p=0.005)forvariationbetweenthetworoomsat night,indicating greater lighting variationin theordinary room(Table4).

Lightingexperiences,PartII

Whenanalysingtheinterviews,fivequestionsfromthe inter-view guidecould be answered withyes or no. The result indicated that nearly all the patients were pleased with the lighting environment in the intervention room. They sleptworseintheICUthanathome.Nearlyallthosewho experienceddisruptedcircadianrhythmalsohadnightmares (Table7).

The analysis of the interviews is presented in text in thefollowingmaincategories(headings)andsubcategories (underlined)(Table8).

Adynamiclightingenvironment

This category describesexperiences suchaspleasantness, levelsof lightingsand variation. Most, but notall, of the patientscouldtalkabouttheirmemoriesandexperiencesof

Table8 Patients’experiencesoflighting/lightintheinterventionroompresentedincategoriesandsubcategories,PartII.

Adynamiclightingenvironment Impactoflighting onpatients’sleep

Theimpactof

lighting/lightsimpacton thecircadianrhythm

Thelightingcalms

Pleasantandhealthy lightings

Bothpoorandgoodnight timesleep

Diverseperceptionsof theregularityofdayand night

Anxietyandsearching forsecurity

Acceptablelighting levelsatnights

Levelsaffectingsleep Disturbingimpact Severeanxietyreplaced bycalm

Variationsinthelighting roundtheclock

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thelightingandthedaylight,bothinthedayandatnight; othershadonlysporadicmemories.

Patients who recalled the light environment generally talked about apleasantandhealthylighting environment, asonepatientsaid:

‘‘Itwasnice,itwasnotsharpanditwasapleasantlight’’ No23.

The lighting affected their wellbeing and health posi-tively.Theclearmorninglightwasimportantasitincreased alertness andaffectedtheirmood inagoodway. Lighting wassometimestakenforgrantedandthepatientshadnot alwaysreflectedonitduringtheirstayintheICUbutthey wereabletocompareitwithanotherlightingenvironments e.g.oftenthelightingenvironmentathomebutalsothaton otherhospitalwards,includingtheonewheretheinterview wasperformed.Onepatientsaid:

‘‘Ityouthinkback,itismuchmoreupliftingtobeinthat light(attheICU)thanthis(onageneralward).’’No8.

Several patients recalled that there were acceptablelightinglevelsatnight. It was not completely dark but more like twilight. Most did not experience the lightlevelsatnightasdisturbingalthoughtheywereaware thatthelightwasbrighterthanathome.Onepatientsaid:

‘‘Itisobviousthatitwasquiteabrightlightbutwedonot havecompletedarknesswherewesleepeither...itdoes

nothurtme tosleepin half-brightlight,sotospeak’’. No14.

Lightinglevelswereassessedasacceptable.Therewere patientswhowantedbrightersurroundings.Someassessed thelighting levelsasalmosttoohigh buttheyunderstood that the levelswere a compromise. The room in the ICU was notonly a placefor patients; it was also a placeof workforstaffandthepatients’demandsconcerninglighting levelsthatwerenottheonlyimportantissue.Asonepatient expressedit:

‘‘Itcouldhavebeendarker,butthestaffmustbeableto worktheretoo’’.No9b.

Experiences ofvariationsinthelightingroundtheclock werealso described.There weredifferent opinionsabout whether the lighting varied between day and night and duringtheday.Someofthepatientsexperiencedclear dif-ferencesinthelighting betweenday andnight.Theyalso noticedthatthelightwasdimmed duringtheeveningand became darker at night.The variations in lighting during thedaywerehardertodetect.Afewreportedavague feel-ingabout changes in lightinglevelsand colourduring the day.Thetransitionsbetweenthedifferentlightsceneswere softandun-disturbing.Mostdidnotnoticethetransitions butinsteadthoughtthatthelightingfollowedthedaylight outsidethewindows.Onesaid:

‘‘Yes ithas varieddependent on howit wasoutside, I havenoticedthatat7(pm)whenitstartedtogetdark outside,atthesametimeitgotdarkerinsidetoo,itwas probablysomekindofcombination’’.No23.

Impactoflightingonpatients’sleep

Thiscategorydescribes’experiencesofsleepandhowlight isrelatedtosleep.Patientsemphasisedtheimportanceof sleep,forrecoveringandregaininghealth.

Bothpoorandgoodnighttimesleep was experienced. Patientswhoreportedpoor sleepqualitymentioned diffi-cultiesgettingtosleep,nightswithnosleepatallornights withfrequentwakeningsandwithfragmentedsleep.

‘‘Bad,Ihaveonlysleptforperiodsof30to45minutes, thenIwaswokenup.Ithasnotbeenanevensleep,one ofthelongestnightsforages’’.No26.

Othersfelttheysleptwell:

‘‘Yesrelativelywell,Ihavetosay.No27.

Lightinglevelsaffectedtheirsleepbutthepatientshad different opinions about the lighting levels in relation to sleep.Someofthemwanteditdarkerwhileafewwantedit brighter.Mostfeltthatthelightinglevelswereappropriate. Itwasnotsobrightthatitwasdisturbingbutbrightenough toorientatethemselvesintheroom.Onesaid:

‘‘...itwasgoodthatyoucouldseealot,andyouwere

notinsideadarksack,sotosay’’.No22.

Somepatientscurrentthepresentlightinglevelstothe abilitytosleep.Thelightingcouldbeonereasontheirsleep wasdisturbed.Onepatientsadaboutsleep:

‘‘Abysmal,thankstoitbeingsobright.’’No19.

Otherpatientsthoughtthatthelightinglevelswere mod-erateforsleepingin.Thefactthatthepatientswereableto talkabouttheirexperiencesandsawapositiveconnection betweensleepanddarknesswasclarifiedintheirreflections concerningsleepandrestduringtheday.Mostofthemhad sleptonandoffduringthedaydespitethedaylightandthe lightingandweresurprisedaboutthis.Asoneexpressedit:

‘‘Youhavetakeniteasy,evenifthelightwasswitched on,youweresotiredthatyoucouldjustcloseyoureyes forawhile,thenyoufellasleep’’.No23.

Theimpactoflighting/lightsonthecircadianrhythm

This category describes patients’ experiences concerning circadianrhythmanditsrelationshiptolight.

Thepatientshaddiverseperceptionsoftheregularityof dayandnight.Forsomeitwashardtokeepanormalrhythm whichinturnledtobeingconfusedabouttimeandtheloss oftheabilitytodistinguishbetweendayandnight,which wasperceived asvery difficult. Another interviewee also mentionedthissaying:

‘‘NoIhavenotbeenabletodothat,forexampleinthe night when theytold me that thetime was2 am....it

cannotbetrue,itisinthemiddleoftheday’’.No6.

Otherswerecompletelyorientedastotimeandit was completelynatural andeasy forthemtoseparatedayand night.Onerelatedtheabilitytoseparatedayandnightto hishealthsituation,saying:

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Lighting’s disturbingimpact on the circadian rhythm whenitwasswitchedonbythestaffduringthenight,was reportedandexpressedasfollows:

‘‘Whenthelightwasswitchedon,Ididnotknow(ifitwas dayornight)becauseitwasbasicallythesamelight’’. No13.

Thelightinglevelswereconsideredlowbutatthesame timebrighterthanathome.Thiswasperceivedbyafewas disturbingthemaintainingofthecircadianrhythmandone said:

‘‘It was a good lighting environment, without dazzle. Thenthelighting wasreducedat 10pm,Ithink,butit didnothelpme(toorientateaboutdayandnight)’’.

In answer tothe question about whathelped to main-tainanormalcircadian rhythmthelightinginsideandthe daylightsupportingimpactofthewindowswerementioned. Bothlight and darkness were important for the circadian rhythm.Answeringaquestionabouthowithadbeenpossible todistinguishbetweendayandnightonepatientsaid:

‘‘It is the light and everything, the sun is shining outside...Yes and when the lights were turned up and

downIwasabletofollow(thedayandnight),ohyes...’’.

No9

Thelightingcalms

Thiscategorydescribesexperiencesofanxietyorsecurity. The following descriptionsshowhow thelighting clarified theenvironmentandhowanxietywasalleviatedbylight.

Patients often experienced anxietyandsearchedforsecurity in their surroundings. Theyponderedmoreover theirhealth situationand prog-nosis at night and their thoughts could sometimes result infeelingsof anxietyandfearof losingcontrol overtheir situation.Onepatientsaid:

‘‘Yes,itwasanight,thesecondorthethird,whenyou thoughtthat.ThenIhad alotof painandsleptbadly, whathashappening?Isthisthewayeverythingwillend? No14.

Others felt secure in spite of the unfamiliar environ-mentandtheirvulnerablesituation.Thepatientsconnected to their inner security, which they felt was independent of the surrounding environment. The lighting environ-ment alsoaffected their possibilityof feeling secure and the light allowed severeanxietyreplacedbycalm. Some patients had been totally terrified during the nights but therewere alsothose whofelttrust andhad been calm. Anolderpatientrememberedhowhismothergotthe chil-drentosleepintheevening,byleavingthelightsswitched on.Severeanxietywasalleviatedbylightduringthenight. Duringthemostworrying period,abedside lampcould beused.This contributed tofeelingsof calmness, asone patientsaid:

‘‘....Itgotbetterwhenthelightwasswitchedon.Itfelt

moresecureinaway’’.No13.

Mostofthepatientsconsidered thelightinglevelshigh enoughforthemtofeelsecure.

Despitetheroombeingwell-litsomepatientsfelleasily asleepandsleptwell duringtheday.Somedescribed that theyslept, onandoff; the light wasnotdisturbing; staff werearoundthemandtheyfeltsecure.

Thelightingclaritycreatedsecurity by lighting up the surroundings. Light was a prerequisite for perceiving the surroundingobjectsintheroominarealisticway.Fearand anxietycouldoccurwhenthepatientswereunableto ori-entatethemselvesintheroom.Thelightinglevelsenabled themtoseeandidentifythestaff.Thestaffplayedan impor-tantroleincreatingcalminthepatientsandbeingableto see them and have aface tofocus onwascomforting. It confirmed that they existed and that someone wasthere andabletohelpthem.Onepatientexpressedthis:

‘‘...securitywere moreabout seeingthe staff...’’. No

19.

Discussion

Reflectionsonthefindings

Thisstudydoesnotshowclearlythatthecurrentlight inter-ventionaffected suchfactorsasmaintenanceof circadian rhythm withsubsequent benefittothe patient’srecovery. However,developingknowledgeaboutpatientexperiences oflightenvironmentsandtheirrelationtocircadianrhythm andhealthisanimportantstartingpoint.Thepresentstudy showsthatpatientscouldthinkaboutandassesslight envi-ronments despite severe illness and complex treatments. This is animportant result.Ourfindingsindicate acycled light system in advantageous and that people continu-ouslyinteractwiththeirsurroundingenvironment(Olausson et al.,2013; Rashid, 2006). Light is one importantfactor inthisandourfindingsaremeaningful,butmoreresearch needstobedone.

The results from the questionnaire showed significant differences in favour of the intervention room regarding factorforbrightnessindaytime.Thisfactorcomprisedthe adjectiveslight,weak,drabandbrilliant.Accordingto pre-vious knowledge, itis importanttoget bright lightin the morningandinthedaytimetostartupandsupportthe cir-cadianrhythm.Brightlightinthemorningincreaseshuman alertnessandmood,bysuppressingthehormonemelatonin (highestinthenight)andincreasingcortisol,thehormone of alertness (Chan etal., 2012; Fiigueiro andRea, 2010). Thesechangesinhormoneactivityduetolightlevelsareone importantpart ofthecircadianrhythm whichinturn sup-portshealth.Resultsfrompreviousmeasurementsoflightin theinterventionroomreportedluxvaluesas615between 8and10am(Table1,Engwalletal.,2014).Togetherwith thepresentstudy’sresultsitindicatethatthecycled light-ingenvironmentbettersupportpatients’circadianrhythm thanthelightingenvironmentintheordinaryroom.Inthis roomonlythelightingatwallnormallywereswitchedonin daytimeandheretheluxvalueswereonly147.Lightingsin ceilingandwallsreportedvaluesat810lx(Table2).These highvaluesoflightwerenormallyonlyafactwhenspecial examinationswereperformed.

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atnighttime(8—8.45pm)andassessedthelighting environ-mentasmorevarying.Thefactorforvariationcomprisedthe adjectives concentrated, evenly distributed and focused. The patients maybeidentifieda coupleof differentlight sourcesthatspreadthelightin ashiftingway.Incontrast to the intervention room where the indirect light spread the light more uniformly, as here shone upwards in the ceilingand on thewall. A smooth,well distributed light-ing environment without partsof dark shadows andglare is recommended and is more comfortable for individuals (CanadianCentreforOccupationalHealthandSafety,2014). The intervention room is not only a place where the patientcanrestandrestore.Itisalsoaplacewherethestaff shouldbeabletoworkandthelightlevelsshouldpromote writingandallowassessmentofpatients’conditionsandbe abletoreadandwatch overthetechnologicalequipment. Patientswereawareofthissituationwhentheyassessedthe lightlevelsatnightasacompromise.Inspite ofimpaired healthconditiontheyinteractedwiththephysical environ-mentandthestaffandwereabletoprioritiseothers’needs beforetheirown.Onewaytoovercomecompetinglighting demands is to includepatients, staff and relatives in the designprocedure(Perkins,2013).

Most patients reported that their sleep was worse in

the ICU than at home. This corresponds with previous

research (Littleet al., 2012) where light was one of five mostfrequentlycitedreasonsforsleepdeprivation.These researchers proposed nocturnal modification such as dim lightthat canbecomparedwithourcycledlighting inter-vention.

Nineintervieweesreporteddisruptedcircadianrhythm. This is also well-known from previous research (Verceles et al., 2012). Eight of these nine patients also reported

nightmares or visions and seven slept badly and were

mechanically ventilated. Sleep disorders, nightmares and disrupted circadian rhythm are present in patients with

ICU delirium and previous research shows that 60—80%

of mechanically ventilated patients and 20—55% of non-ventilated ICU patients with experiences from delirium (Pisanietal.,2009;Thomasonetal.,2005).

Patients’ inner clocks were perceived as being incon-sistent withclock time, a knowneffectof light exposure betweenmidnightanddawninmammals(Hutetal.,1999), asitturnstheinnerclockbackwards.Earlierresearchshows that brighterlight affectsthe inner clock more than dim light(Duffyetal.,1996).Somepatientsinthepresentstudy reportedverydisturbedinnercircadianrhythmsaswellas lightexposureatvariouspointsthroughthenight.The light-ing levels also, however had a comforting effect on the patientsinthenightastheycouldseeandrelatetostaff. This findingisin agreementwithstudies inan emergency wardwherepatientssaidthatseeingthenurseenteringthe roomincreasedtheirsenseofsafetyandsecurity(Shattell etal.,2005).

The cycled lighting environment based on scientific researchconcerninglight,circadianrhythmandhealthwas reportedaspleasantby16/17 interviewed.Froma caring perspectiveit is importanttoreflect onpatients’ individ-ual experiences. It is important with a balance between supporting the circadian rhythm by lighting and making patientsfeelsafeandcomfortable.Themostpositivewayof designingalightingenvironmentmightbetoallowpatients

to decide individually about in the lighting environment tomeet theirrequirements (Thompson etal., 2012). The patient is in many ways the caring expert and it is very important that their preferences should guide the caring process(Coulter etal., 2008).It is alsopossible that dif-ferentdiseasesandhealthconditionsmayrequirediffering light environments. In the future, the ability to individu-aliseanenvironmentallightingprotocoltomeettheneeds ofeachpatientwouldbeidealin creatingamore healing environmentintheICU.

Knowledgeaboutpatients’perceptionsandexperiences oflightenvironments,togetherwithphysicalmeasurements oflightinganddaylight’sroleinestablishingthecircadian rhythmareconsideredusefulforfutureresearch.

Criticalreflections

Two differentmethodological approaches were used. The questionnairehasbeenusedin previousstudies butisnot designed specifically for ICU environments. The 17 ques-tionswererelativelyeasytocomplete butpatientfatigue andreduced ability to concentrate could bea weakness.

However, many patients completed the questionnaire by

themselvesoraskedtheresearcherforsupplementary infor-mation.Mostofthepatientsweretiredandexhaustedwhich precludedopen-endedinterviews.Aninterviewguidewith shortandsimplequestions(KvaleandBrinkmann,2009)was usedasmoresuitedtothepatients’conditionandabilityto narratetheirexperiences.Onepatientwasabletonarrate spontaneouslywithoutsupportfromtheinterviewguide.In other cases thequestionnaire worked well in relation for itspurpose.Contentanalysiswasfoundusefulforanalysing relativelyshorttranscriptions.

Somepatientsusedtheinterviewsasachancetovoice their ICU experiences in general. Interviews may have a supportingfunctioninprovidingthepatientswiththe oppor-tunity to have somebody listen who is familiar with ICU careandthusabletounderstand(NordentoftandKappel, 2011).The interviewer (ME)is experienced inprehospital andcriticalcareandtheotherresearchers,apartfrombeing experienced in intensive care, arealso familiar with ICU research.Interviewsallowfollow-upquestionstobeasked, giving a deeper and clearer understanding. Today’s seda-tionpracticeshavemovedfromadeepertowardsalighter sedationregimen.Thisissomethingtoconsideraspatients aremoreawakeandthussensitivetothesurroundingspace (Egerodetal.,2013).

Allocationof patientstothetworoomswassometimes determinedbytheirspecialneedsintheICU.However,no significantdifferencesbetweenthetwogroupswerefound inrelationtosex,age,useofrespiratorandSAPS.Thismade itpossibletocomparethetwopatientgroups’experiences oflight.

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inthestudyastheywereunabletocooperate.Theywere includedintheexclusiongroupandhadsignificantlyhigher SAPSvaluesandmechanicalventilatoruse(Table3). Unfor-tunatelythisgroup’sexperiencesweremissed.Theresearch group had joint discussions concerning the analysis. The quotationsin the result section arean expression of the authenticityoftheparticipants’statementsandthecontext (EloandKyngäs,2008).

Conclusions

Manyof the patientsin the ICU had experiences of sleep disordersanddisruptedcircadian rhythms. Acycled light-ing system that copied the natural light was considered

important and was assessed as pleasant and together

with daylight, supported for the circadian rhythm. Most patients were aware of and able to assess light environ-mentseveniftheyhadexperiencesfromcriticalillnessand treatments.Appropriatelightinglevelsintheenvironment helpedpatientsandstafftoconnecttoeachother, which engenderedfeelingsofcalmandsecurity.

Acknowledgements

Thanks to Fagerhults Lighting AB for constructing and

installing the cycled lighted system, Annelie Ryberg,

Anna-KarinWindellandEwaLagerströmforexcellenthelp with the data collection, Göran Jutengren for important guidance regarding statistics and Pat Shrimpton for the languagereview.

Funding

Theauthorshavenosourcesoffundingtodeclare.

Conflictofintereststatement

Theauthorshavenoconflictofinteresttodeclare.

Ethicalstatement None.

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