Encyclopedia of Trauma Care

47 Pages·0.948 MB·English

by  Peter Papadakos, Mark Gestring (eds.)

G
Gut Mucosal Atrophy functions, including digestion and nutrient
absorption;itservesasabarrierandhasimmuno-
IndraneilMukherjee1andKhanjanH. logical properties as well. It is also adaptable to
Nagarsheth2 many situations like starvation, metabolic dis-
1TheSoutheasternCenterforDigestiveDisorders eases, and intestinal surgery. These adaptations
&PancreaticCancer,AdvancedMinimally canbeeitherproliferativeoratrophic.
Invasive&RoboticSurgery,FloridaHospital Enterocytes are the dominant cells that form
Tampa,Tampa,FL,USA theintestinalbrushborder.Themicrovilliattheir
2RAdamsCowleyShockTraumaCenter, luminal end are the functional component
UniversityofMarylandSchoolofMedicine, containing the enzymes and the glycocalyx coat
Baltimore,MD,USA thatactsasaphysicalbarrier.Themucosalsurface
forms villi by extensions of the lamina and then
thesubmucosafoldstoformtheplicaecirculares.
Synonyms Thisspecificanatomicalfeatureincreasesthesur-
face area. The mucosa is formed by crypt-villus
Intestinalepithelialapoptosis;Starvation-induced unitswhichincludethestemcells,whichgiverise
smallbowelatrophy to the progenitor cells. These progenitor cells
furtherdifferentiateintoabsorptiveandsecretory
cells.Thestemcellsarepresentthroughoutlifein
Definition thecrypts;theirproliferationisregulatedviamul-
tiple signals ranging from external diet to hor-
Mucosalatrophyisdefinedasanatomicalchanges monesandimmunity.
in the intestinal mucosa such as reduced number In proliferation there is an increase in villus
of cells, decreased surface area, and shortened height, crypt depth, and surface area. In the aug-
villous height and crypt depth, with subsequent mentationofintestinalfunction,thereisincreased
lossofintestinalfunction. functionofnotonlytheepithelialcellsbutalsothe
deeper cells, such as blood vessels and secretory
cells.
PreexistingCondition Finally,thelastkindofadaptationisatrophy.It
usually is a result of starvation which reduces
The gut mucosa starts at the vermilion border at enteralnutrition.Supportingthepatientwithade-
thelipandextendstothedentatelineattheanus. quate parenteral nutrition has been unsuccessful
Theintestinalmucosa,inparticular,servesmany inpreventingatrophy.Theatrophicchangesresult
#Springer-VerlagBerlinHeidelberg2016
P.J.Papadakos,M.L.Gestring(eds.),EncyclopediaofTraumaCare,
DOI10.1007/978-3-642-36200-2_134-1
2 GutMucosalAtrophy
inafailureoftheadaptivefunctionsofprolifera- therapyinextremecases.Therearemanyknown
tion,augmentation,anddifferentiation aswellas side effects and complications associated with
increasedapoptosis. chronicparenteralnutritionuse.Thesecomplica-
Multipleanimalstudieshavefoundthatmuco- tions include catheter malfunctions, infections,
salatrophyischaracterizedbyadecreaseinintes- andliverfailure.Insuchsituation,seriousconsid-
tinal weight and nitrogen content. The intestine eration should be made about smallbowel trans-
has fewer Peyer’s patches and T cells, thereby plant and management by a multidisciplinary
decreasing the immunological capabilities. The team(Modietal.2008).
mucosal hypoplasia is mediated by an alteration Thetherapyinthissituation shouldbegeared
inthetumornecrosisfactor(TNF)-a/EGFsignal- towardreversingmucosalatrophyandpromoting
ingpathway.Theuseoftotalparenteralnutrition adaptations by proliferation, augmentation, and
(TPN) may actually cause enterocyte apoptosis differentiation.
andstimulationofionsecretion,viaintraepithelial Even small amounts of enteral nutrition can
lymphocyte-derivedinterferon-gamma,causinga improve intestinal epithelial growth, motility,
decrease in the barrier function of the mucosa. and absorption (Perdikis and Basson 1997).
Direct contact with luminal food and chyme has Lipids in the diet as well as its use in parenteral
alsobeenfoundtobeimportantformucosalinteg- nutrition add significant benefit. Luminal lipids
rity(Shawetal.2012). havebeenshowntoincreaseadaptationandfunc-
Mucosalatrophyisasignificantprobleminthe tion of the mucosa. Short-chain fatty acids are
settingofstarvation.Inthemilieuofmodern-day shown to reduce mucosal atrophy and promote
healthcare,itisamajorprobleminthesettingof adaptation. Proteins and amino acids like gluta-
trauma. In these scenarios, gut mucosal atrophy mine improve gut mucosal health by enhancing
increases sepsis rates dramatically (Kudsk mucosalfunctionandretardatrophy.Supplements
etal.1992).Itisalsoevidentinprolongedstarva- like retinoic acid and ornithine a-ketoglutarate
tion for various medical conditions like pancrea- havealsoshowntoimproveadaption.Antibiotics
titis and short bowel syndrome. Short bowel may reduce malabsorption and reverse mucosal
syndromeisusuallysecondarytointestinalresec- atrophybyreducingbacterialovergrowth.Epider-
tions for inflammatory bowel disease, ischemia, mal growth factor and glucagon-like peptide-2
and obstruction. In the pediatric age group, it is have also been used in many controlled settings
mostly seen in cases of necrotizing enterocolitis, to improve adaptation. Experimental therapies
intestinal malrotations, and atresias. Total paren- using leptin, bombesin, and ghrelin may be used
teral nutrition is used to manage prolonged star- inthefutureforthispurpose.
vation but may not be beneficial in this regard
(Sax 2010). These can be significant enough to
cause“intestinalfailure”andfailuretothrive.Itis Cross-References
seen when the absorptive surface is so low that
patientshavediarrhea,dehydration,malnutrition, ▶NutritionalDeficiency/Starvation
andelectrolytedisturbance. ▶NutritionalSupport
Application
References
Totalparenteralnutritionhasbeenthemainstayof
KudskKA,CroceMA,FabianTC,MinardG,TolleyEA,
management for intestinal failure. This form of PoretHA,KuhlMR,BrownRO(1992)Enteralversus
nutritioniscriticalintheshorttermandinmany parenteral feeding. Effects on septic morbidity after
blunt and penetrating abdominal trauma. Ann Surg
cases is needed on a chronic basis to maintain
215:503–511,discussion511–513
homeostasisandelectrolytebalance.Totalparen-
ModiBP,LangerM,ChingYA,ValimC,WaterfordSD,
teral nutrition should only be used for long-term IglesiasJ,DuroD,LoC,JaksicT,DugganC(2008)
GutMucosalAtrophy 3
Improved survival in a multidisciplinary short bowel SaxHC(2010)Managementofshortbowelsyndrome.In:
syndrome program. J Pediatr Surg 43(1):20–24. CameronJL,CameronAM(eds)Currentsurgicalther-
doi:10.1016/j.jpedsurg.2007.09.014 apy,10thedn.Elsevier,Philadelphia
PerdikisDA,BassonMD(1997)Basalnutritionpromotes ShawD,GohilK,BassonMD(2012)Intestinalmucosal
human intestinal epithelial (Caco-2) proliferation, atrophy and adaptation. World J Gastroenterol
brush border enzyme activity, and motility. Crit Care 18(44):6357–6375
Med25:159–165
G
Gastrointestinal Hemorrhage PreexistingCondition
AndrewS.BrockandJosephRomagnuolo Epidemiology
DivisionofGastroenterologyandHepatology, Gastrointestinal hemorrhage represents a signifi-
MedicalUniversityofSouthCarolina, cant health problem worldwide. In 2009, the
Charleston,SC,USA annualincidenceofhospitalizationsintheUnited
StatesforupperandlowerGIbleedingwas60.6/
100,000 and 35.7/100,000, respectively (Laine
Synonyms et al. 2012). This represents a decline over the
pastdecade,though thereasonfor thisdeclineis
Gastrointestinal bleeding; GI bleeding; GI notclear.
hemorrhage
Etiology
Therearemultiplecausesofgastrointestinalhem-
orrhage(Table1).Pepticulcerdiseaseisthenum-
Definition
ber one cause of upper GI hemorrhage and
diverticulardiseasethenumberonelowersource.
Gastrointestinal (GI) hemorrhage is defined as
Thishasremainedsteadyoverthelastdecade.
bleeding from the GI tract, anywhere from the
mouth to the anus. Traditional terminology uses
Presentation
the ligament of Treitz to demarcate upper from
Patients with GI hemorrhage may present in a
lower GI bleeding. The advent of technologies
variety of ways, from fulminant, life-threatening
capableofaccessingthesmallintestine,however,
bleedingtoslow,occultoozingovermanymonths
has led to the addition of “mid-gut” bleeding,
resulting in unexplained iron deficiency anemia.
whereby upper, mid-, and lower sources refer to
Vomitingblood isdiagnosticofanupper source,
areasaccessible toesophagogastroduodenoscopy
while small amounts ofbrightred blood perrec-
(EGD), enteroscopy, and colonoscopy, respec-
tum in the absence of changes in hemodynamics
tively. Thus, upper GI bleeding now refers to
or hemoglobin represent an anorectal source.
lesions proximal to the papilla of Vater, mid-GI
Melena typically indicates an upper or mid-gut
bleeding includes lesions distal to the papilla of
source, but can also result from a right colon
Vatertotheterminalileum,andlowerGIbleeding
lesion. Lower GI bleeding usually presents with
referstolesionsinthecolorectumandanus.
hematochezia, but it also can represent a brisk
upperormid-gutsource.
#Springer-VerlagBerlinHeidelberg2016
P.J.Papadakos,M.L.Gestring(eds.),EncyclopediaofTraumaCare,
DOI10.1007/978-3-642-36200-2_242-1
2 GastrointestinalHemorrhage
GastrointestinalHemorrhage,Table1 CausesofGIhemorrhagebylocation
Upper Midgut Lower
Ulcer Angioectasia Diverticulosis
Varices Erosions Colitis(ischemia,IBD,radiation)
Gastritis Tumor Hemorrhoids
Esophagitis Polyp Tumor
Mallory-Weisstear Ulcer Post-polypectomy
Dieulafoy Dieulafoy Angioectasia
Angioectasia Crohn’sdisease Polyp
GAVE Celiacdisease Ulcer
Cameron’serosions Meckel’sdiverticulum Dieulafoy
Tumor Diverticulosis
Hemobilia Aortoentericfistula
Hemosuccuspancreaticus
Polyp
Portalhypertensivegastropathy
GAVEgastricantralvascularectasia,IBDinflammatoryboweldisease
Cluestothesourceofbleedingmaybeelicited approximately25 %ofpatientswillhavelesions
fromthemedicalhistory.Patientswithcirrhosisor withinreachofEGDorcolonoscopy.
risk factors for liver disease may have a portal
hypertensiveetiologyofhemorrhage,suchasvar-
ices or gastric antral vascular ectasia (GAVE).
Application
Recent nonsteroidal anti-inflammatory drug
(NSAID)usepredisposestopepticulcerdisease.
InitialManagement
Use of anticoagulants, such as warfarin or
Vital signs must be monitored closely, with con-
clopidogrel, should be noted. Patients who have
sideration for intensive care unit monitoring,
undergone gastrointestinal surgery are at risk for
especiallyforpatientswithactivebleeding,hemo-
anastomotic hemorrhage. Aortic stenosis and
dynamiccompromise,high-risklesionsonendos-
renal failure are risk factors for angioectasia.
copy, suspected varices, advanced age, or major
Malignant GI tumors can hemorrhage. Patients
comorbidities.Labworkshouldinclude,atmini-
with aortic grafts or aneurysms can develop
mum, a complete blood count, basic metabolic
aortoenteric fistulae. A history of retching might
panel, hepatic panel, and prothrombin time with
indicateaMallory-Weisstear.Recentendoscopic
internationalionizedratio(INR).Aphysicalexam
polypectomy or biliary/pancreatic
should be performed, including a rectal exam to
sphincterotomy should raise suspicion for bleed-
assess stool color. Intravascular volume may be
ingfromthosesites.
gleaned from the vital signs; resting tachycardia,
Five percent of patients will have obscure GI
orthostasis, and hypotension are reflective of
bleeding(OGIB).Thisisdefinedasbleedingthat
depleted stores. Prognostic scales such as the
isnotidentifiedonEGDandcolonoscopy.OGIB
Blatchford(pre-endoscopy)andRockall(clinical
is subdivided into obscure occult and obscure
andendoscopic)scorescanaidintriagingpatients
overtbleeding,withtheformerreferringtobleed-
by stratifying them into high- and low-risk cate-
ing from the GI tract resulting in iron deficiency
gories(Barkunetal.2010).Placementofanaso-
anemia and the latter as recurrent melena or
gastric tube (NGT) has not been shown to
hematochezia. The majority of patients with
improveoutcomes;further,upto15 %ofpatients
OGIB will have small bowel lesions, though
without bloody aspirate will have high-risk
GastrointestinalHemorrhage 3
lesions. However, NGT can help distinguish lesionswhengivenpriortoendoscopyandreduce
upper and lower sources in patients with rebleeding, the need for surgery, and mortality
hematochezia with significant hemoglobin drop after endoscopic therapy of high-risk lesions.
and/ormildhypovolemia. This likely has little to no benefit in non-high-
Two large-bore peripheral intravenous risklesions.H2receptorblockershavenotledto
(IV) catheters or a single central catheter should improvedoutcomesandthusarenotindicatedfor
be inserted. Patients with signs of intravascular acute upper GI bleeding. Use of a promotility
depletionshouldberesuscitatedwithcrystalloids agent such as erythromycin or metoclopramide
andbloodproductsasneeded.Transfusionshould can reduce the need for repeat endoscopy by
also be given to patients with a hemoglobin less clearing the stomach of blood and, thus, should
than 7.0 g/dL, though the threshold in patients beconsidered(Gralneketal.2008).IVoctreotide
with underlying coronary artery disease or signs can be added in selected patients with ongoing
of impaired myocardial perfusion may require bleeding(ImperialeandBirgisson1997).
hemoglobin levels as high as 10.0 g/dL. Care Patientssuspectedofhavingvaricealbleeding
mustbetakentoavoidovertransfusioninpatients should receive IV octreotide with a bolus of
with known or suspected varices, as this can 50 mcg followed by an infusion at 50 mcg/h for
increase portal pressures, thus worsening bleed- 3–5days(Burroughs1994).Patientswithcirrho-
ing;atargethemoglobinof8.0g/dLisappropriate sis and GI bleeding should receive IVantibiotics
inthesepatients. asprophylaxisforspontaneousbacterialperitoni-
Anticoagulants and antiplatelet agents should tis. Acceptable choices include cephalosporins,
beheld.Coagulopathyshouldbereversedifsafe such as ceftriaxone, and fluoroquinolones such
todoso,aimingforaplateletcountofgreaterthan as ciprofloxacin. These should initially be given
50 and INR less than 1.5. However, if unsafe, IV,buttransitioncanbemadetooraladministra-
endoscopycangenerallybeperformedinpatients tiononcethepatientisstabilizedtocompletethe
with therapeutic coagulopathy. INR in patients recommended7-daycourse.
with cirrhosis is not predictive of bleeding; thus,
attempts at correction may simply lead to exces- EndoscopicTreatment
sivevolumeexpansion.Consideration ofplatelet Consultation with a gastroenterologist should be
transfusion should also be given to patients on made for all significant bleeds. Once the patient
antiplatelet agents such as aspirin or clopidogrel has been hemodynamically stabilized, including
who present with life-threatening bleeding. In endotracheal tube placementif necessary, endos-
high-risk situations, such as mechanical valves copycanbeundertaken.Earlyendoscopy,defined
or newly placed coronary stents, consultation as within 24 h of presentation, is recommended
withacardiologistshouldbeundertaken. forpatientswithacuteupperGIbleeding(Barkun
etal.2010).PatientswithbrisklowerGIbleeding
MedicalTherapy may also warrant inpatient endoscopy, particu-
Themostimportantlife-savingmedicaltreatment larly if the bleeding persists. Patients with self-
for GI hemorrhage is proper resuscitation and limited hematochezia can undergo outpatient
maneuverstoprotecttheairway;thisshouldpre- colonoscopy.
cedeendoscopyandmostothertherapies.Patients The role of endoscopy in patients with GI
with significant upper GI hemorrhage suspected hemorrhageistodiagnosethesourceofbleeding,
ofhavingahigh-risklesiononendoscopyshould riskstratifythepatient,andtreatthesourcelesion
receivehigh-doseIVprotonpumpinhibitor(PPI) if necessary. Lesions at low risk of rebleeding
therapy(Dorwardetal.2006).High-dosetherapy include peptic ulcers with a clean base or flat
includes omeprazole, esomeprazole, or spot, Mallory-Weiss tear, gastritis, esophagitis,
pantoprazole in a bolus dose of 80 mg followed and non-bleeding angioectasia. Healthy patients
byacontinuousinfusiondoseof8mg/hfor72h. at low risk of rebleeding can be discharged after
This has been shown to downstage high-risk endoscopy. Endoscopic hemostasis should be
4 GastrointestinalHemorrhage
attempted in patients with high-risk lesions, hemostasis. Mechanical hemostasis for ulcers
including ulcers with active bleeding or visible consistsofhemostaticclips,whichworkbygrasp-
vessel,Dieulafoylesions,bleedingangioectasias, ingthevesseltocutoffbloodflow.Thedecision
diverticula with bleeding or visible vessel, and tousethermaltherapyversusclippingisbasedon
varices amenable to endoscopic therapy. All position of lesion and endoscopist preference, as
ulcerswithclotsshouldbeirrigated,buttreatment onehasnotbeenshowntobesuperiortotheother.
ofulcerswithanadherentclotthatdoesnoteasily Further, whether one combines injection therapy
wash with gentle irrigation is at the discretion of witheitherthermalormechanicaltherapyoruses
theendoscopist,whereeitherendoscopictherapy thethermalormechanicaltechniquealoneisatthe
or medical therapy is acceptable. Tumors are at discretion of the endoscopist as there is no evi-
highriskofrebleeding,butarerarelyamenableto dence these approaches result in different
endoscopic therapy. Other lesions may warrant rebleeding rates. A common approach is to use
non-endoscopic therapy; for example, injectiontherapyfirstwhenthereisactivebleed-
aortoenteric fistulae require surgery, hemosuccus ing (to clear the views) or into an adherent clot
pancreaticus may necessitate angiography, and before removal (for prophylaxis against
persistent bleeding from tumors may require bleeding).
angiographicorradiationtherapy. The above techniques may also be used for
There are various modalities of endoscopic other sources of GI hemorrhage. For example,
therapy that may be used. Band ligation is the bleeding diverticula and Dieulafoy lesions may
recommended first-line endoscopic therapy for be treated with any of the techniques mentioned
esophageal varices, though sclerosants such as forulcerhemorrhage,orbybandligation.Endo-
sodium morrhuate may be used when band liga- scopic clipping is often effective for Mallory-
tionisnotfeasible(Garcia-Tsaoetal.2007).Cya- Weisstears.Angioectasiacanbetreatedwithther-
noacrylate glue has recently been introduced for maltechniques,clipping,aswellasargonplasma
thetreatmentofbleedinggastricvarices,thoughit coagulation (APC). APC is a noncontact tech-
is only available at a limited number of United nique that uses a monopolar current. It is most
Statesinstitutionsatthistime. effective for angioectasia, GAVE, and radiation
The armamentarium is broader for proctitis. Hemospray (Cook Medical Inc,
non-variceal hemorrhage. For peptic ulcers with Winston-Salem, NC) is a promising new tech-
high-risk stigmata such as active bleeding or niquethathasnotyetreceivedapprovalfromthe
non-bleeding visible vessel, there are three basic Food and Drug Administration. This technique
categories of therapy: injection therapy, thermal, involves directly spraying a nanopowder onto
and mechanical.Injection therapygenerallycon- thesourceofbleeding,withgoodefficacyinpre-
sistsofnormalsalineorepinephrine,whichworks liminarytrials(Sungetal.2011).
byatamponadeorvasoconstrictiveeffect,respec- Aspirintherapyshouldberestartedinlessthan
tively.Injectiontherapyshouldnotbeusedalone 5–7 days, as soon as the cardiac risk outweighs
asrebleedingratesaresignificantlylowerwhenit rebleeding risk. Helicobacter pylori should be
is applied concurrently with either thermal or eradicated and NSAIDS avoided in both upper
mechanical therapy. Contact thermal techniques andlowerbleedingsources.
include bipolar electrocautery (e.g., Gold probe,
Microvasive Boston Scientific, Natick, MA, and OtherTherapy
BICAP,CirconACMI,Stamford,CN)andheater If rebleeding occurs once after successful endo-
probe(OlympusCorp.,LakeSuccess,NY).These scopic hemostasis, randomized trial data shows
methods work by coaptive coagulation, whereby repeatendoscopytobesaferthansurgery.Second
the probe is applied directly to the lesion or third rebleeding episodes should have other
(coaptation) and an electrical current is applied options considered. If endoscopic therapy fails,
(coagulation). This compression of the vessel or thelesion isnotamenableto endoscopicther-
with subsequent cautery enables effective apy, other modalities may be used. For example,
GastrointestinalHemorrhage 5
transjugular intrahepatic portosystemic shunting include radionuclide scan, Meckel’s scan, com-
(TIPS) is used in appropriate patients with puted tomographic (CT) angiography, CT
variceal bleeding, with its most feared adverse enterography (CTE), and the newer triple-phase
event being encephalopathy (30 %). CTE. Intraoperative enteroscopy is reserved for
Angiography-guided hemostasis can be patientswithlife-threateningsmallbowelhemor-
performedforhemorrhagefromulcers,Dieulafoy, rhagethatisnotresponsivetomoreconservative
angioectasia, and diverticula, with contrast- therapies,asthisoperationcarriessignificantmor-
induced nephropathy being the most important bidityandmortality.
adverseevent.Asnoted above,radiationtherapy
canbeusedfortumorhemorrhage.Surgeryisnow
consideredalastresortforanyformofGIbleed- Cross-References
ingandisrarelyneededcurrentlyduetoimprove-
ments in medical and endoscopic therapy. An ▶Curling’sUlcer
exceptionishemorrhagefromarecentanastomo- ▶Cushing’sUlcer
sis,whichmayrequiresurgicalrevision;also,the ▶Gastritis
airandstressontheanastomosisfromendoscopy ▶Gastrointestinal Bleeding: Indications for Pro-
aregenerallycontraindicated. phylaxisPost-traumaandTreatment
Patients with OGIB (negative EGD and colo- ▶Hemorrhage
noscopy)shouldundergocapsuleendoscopyafter ▶HemorrhagicShock
consideration is given to repeating EGD and/or ▶TransfusionThresholds
colonoscopy. Repeat standard endoscopy is par-
ticularly useful in cases where views on initial
procedures were compromised due to blood, References
poor prep, or other factors. It remains unclear if
non-bleeding diverticula on colonoscopy in a BarkunAN,BardouM,KuipersEJetal(2010)Interna-
patient with hematochezia defines a “negative” tionalconsensusrecommendationsonthemanagement
of patients with nonvariceal upper gastrointestinal
colonoscopyornot,givenitisthemostcommon bleeding.AnnInternMed152:101–113
lower source. If a lesion is identified on capsule BurroughsAK(1994)Octreotideinvaricealbleeding.Gut
endoscopy,orthepatientcontinuestobleedfrom 35:S23–S27
DorwardS,SreedharanA,LeontiadisGIetal(2006)Pro-
an unknown source, enteroscopy may be under-
ton pump inhibitor treatment initiated prior to endo-
taken.Theformofenteroscopyisdrivenbylesion
scopic diagnosis in upper gastrointestinal bleeding.
location,withtheoptionsbeingpushenteroscopy CochraneDatabaseSystRev7:CD005415
or deep enteroscopy. Deep enteroscopy consists Garcia-TsaoG,SanyalAJ,GraceNDetal(2007)Preven-
tionandmanagementofgastroesophagealvaricesand
of double-balloon enteroscopy, single-balloon
variceal hemorrhage in cirrhosis. Hepatology
enteroscopy, and spiral enteroscopy and may be 46:922–938
approachedfromanantegrade(peroral)orretro- GralnekIM,BarkunAN,BardouM(2008)Management
grade(peranus)direction.Hemostaticcapabilities of acute bleeding from a peptic ulcer. NEJM
359:928–937
mirror those of standard endoscopy discussed
Imperiale TF, Birgisson S (1997) Somatostatin or
above, except banding, which cannot be accom-
octreotidecomparedwithH2antagonistsandplacebo
modated by enteroscopes. However, the efficacy inthemanagementofacutenonvaricealuppergastro-
ofenteroscopictherapyislessclear,andrandom- intestinal hemorrhage: a meta-analysis. Ann Intern
Med127:1062–1071
izedoutcomedataarelacking.Asianandyounger
LaineL,YangH,ChangS-C,DattoC(2012)Trendsfor
cohorts have a higher incidence of small bowel
incidenceofhospitalizationanddeathduetoGIcom-
tumors, which may require surgery after plicationsintheUnitedStatesfrom2001to2009.Am
localization. JGastroenterol107:1190–1195
SungJJ,LuoD,WuJCetal(2011)Earlyclinicalexperi-
Hemodynamically unstable patients with
ence of the safety and effectiveness of hemospray in
OGIB should undergo angiography. Other tests
achievinghemostasisinpatientswithacutepepticulcer
for patients without a bleeding source identified bleeding.Endoscopy43:291–295
O
Organ Donor Management management practices in the intensive care unit
in the pre-retrieval phase and the current state of
LaveenaMunshi1andJeffreyM.Singh2 theevidence.
1ClinicalAssociate,CriticalCare,MountSinai
HospitalandUniversityHealthNetwork,
UniversityofToronto,Toronto,ON,Canada PreexistingCondition
2CriticalCareMedicine,UniversityHealth
NetworkandAssistantProfessor,Divisionof Pathophysiology
CriticalCare,UniversityofToronto,Toronto, Understandingthepathophysiologicchangesthat
ON,Canada occur pre-, peri-, and post-brain death is impera-
tive to ensure optimal management of this popu-
lation. Brain injury is associated with
Synonyms vasoregulatorydysfunction,multifactorialshock,
andhormonederangements,allofwhichmakethe
Brain-dead donor; Donation after cardiac death; managementofthepotential organdonorachal-
Donormanagement;Neurologicdeterminationof lenge(Table1).
death;Potentialorgandonor Neurologic:Brainstemischemiaisduetothe
primary neurologic injury and further worsened
byelevationsinintracranialpressurethatdevelop
Definition duringbrain death. Prior toherniation,hyperten-
sionmayoccurasacompensatorymechanismto
Advancementsintransplantmedicine havefacil- protect cerebral perfusion in the face of rising
itated lifesaving therapeutic options for patients intracranial pressure. As the organ donor pro-
with end-stage organ failure. Despite major gresses to brain death, pontine ischemia occurs
advancesinsurgicaltechniques,immunosuppres- first, resulting in mixed vagal and sympathetic
sive pharmacology, ex vivo assessment and the stimulationthatmanifestsastheclassicCushing’s
expansion of the donor pool using living-related responseofbradycardia,hypertension,andirreg-
donors, the supply of donor organs continues to ular breathing. Unopposed sympathetic stimula-
fall short of the demand for organs by potential tion follows during medullary ischemia which
recipients.Meticulous intensivecaredonor man- resultsintransienthypertensionwithmassivecat-
agement strategies can increase the number and echolamine release. Cerebral herniation and spi-
quality of organs eligible for transplant. This nal cord ischemia are the final pathways which
chapter will provide an overview of donor result in a blunted sympathetic nervous system,
#HerMajestytheQueeninRightofCanada2016
P.J.Papadakos,M.L.Gestring(eds.),EncyclopediaofTraumaCare,
DOI10.1007/978-3-642-36200-2_256-1
2 OrganDonorManagement
OrganDonorManagement,Table1 Overviewofpathophysiologicchangesandmanagement
Condition Mechanism Management
Shock
Hypovolemic Under-resuscitationpretransplant Fluid(crystalloidorcolloid)
Diabetesinsipidus Endpoints:MAP>60–65,sBP>90,
normalizedlactate,u/o>0.5cc/kg
IdentificationandreversalofDI(desmopressin,
vasopressin,fluids)
Cardiogenic Myocardialnecrosis,subendocardialischemia, Cautiousadministrationoflowest-dose
oxygen-freeradicals inotropicsupportneededtomaintainend-organ
perfusion
Vasodilatory Spinalcordischemiabluntingsympathetic Vasopressin
responseandlossofcatecholamines Dopamine
Norepinephrine
Epinephrine
Phenylephrine
Hormone Lossofanteriorandposteriorpituitaryfunction AntidiureticHormone–fluid,desmopressin,
therapy (antidiuretichormone,adrenocorticotropic vasopressin
hormone,thyroidhormone,growthhormone) T3/T4–thyroidreplacementwith
triiodothyronineorthyroxine(controversial)
ACTH–methylprednisolonea
Hyperglycemia–insulin
Empiricapplicationofreplacementversus
targetedversusinthesettingofhemodynamic
instabilityvariesamongprograms
Ventilation
Ventilator- Associatedwithtraumaticbraininjury,micro- Preventionandtreatment
associated aspiration,impairedhostdefensemechanism
pneumonia
Pulmonary Over-resuscitation Diuresis
edema Cardiogenicfromimpairedcontractilityinsetting Cautiousfluidadministration
ofbrainstemdeath Noroleforbetaagonists
Cardiomyopathyassociatedwithneurologic
injury
Vasoconstrictioncrisisacutelyelevatingleft-sided
cardiacpressure
Ventilator- Volutrauma,biotrauma,atelectraumaleadingto Earlyresearchsuggestingbenefitoflung-
associated systemicinflammation protectiveventilationstrategies
lunginjury
MAPmeanarterialpressure,ACTHadrenocorticotropinhormone
aEvidencesurroundingwhattoreplace,whentoreplace,andhowtoreplacecontroversial
decreaseincatecholaminesandvasculartone,and insufficiency), hypovolemic shock (diabetes
vasodilatory shock. The transient hypertension insipidus, volume depletion, hemorrhage related
followed by a profound drop in blood pressure to trauma), and cardiac dysfunction
can threaten organ viability. Neurohormonal (catecholamine surge, hormonal derangements,
changes ensue as posterior pituitary gland func- orsubendocardialischemia).
tionisimpaired. Pulmonary: The lungs are especially vulnera-
Cardiac: Cardiovascular changes that follow ble to injury during the process of death due to
includevasodilatoryshock(inflammation/adrenal aspiration, trauma, and hydrostatic and