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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_725_Библиотеки_им_академика_М_И_Перельмана
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whichtypicallyincludesacompletebloodcount,routinebloodchemistry
andserumamylase plusorminuswhateverisfashionable,thesoup de
jourifyoulike,andaplainX-rayoftheabdomen(AXR).Asyouknow,in
many centers the latter has been replaced with the knee jerk of a CT.
These ‘routine’ tests have a very low diagnostic yield and arenot cost
effective.However,theyarealsoanunavoidablepartoflifeintheER
and are often, if not usually, obtained before the surgical
consultation.
Forsomesurgeonstheclinicalfindingofclear-cutdiffuseperitonitis is
still an indication to proceed with laparotomy or laparoscopy with no
furtherimaging. But whatappearsclear-cut to theexperiencedsurgeon
—rememberthathetoomaybewrong—maybelesssoforyou.And
pleasebearinmindthefollowingcaveats:
•
Intestinal distension associated with obstruction or inflammation
(e.g.enteritis or colitis) mayproducediffuse abdominaltenderness
— mimicking ‘peritonitis’.The whole clinical picture as well as the
AXRwillguideyoutowardtheproperdiagnosis( Chapters21and
27).
•
Acutepancreatitis may presentwith clinical acuteperitonitis. You
should always obtain a serum amylase or lipase level in every
patient with significant abdominal pain in order to avoid falling into
the not uncommon trap of unnecessarily and dangerously
operatingonacutepancreatitis( Chapter19).
•
Clostridium difficile enterocolitis should be considered in any
patient who receives, or has recently received, any quantity of
antibiotics.This may present — from the beginning — even as an
acute abdomen without diarrhea. Here, the optimal initial
management is medical and not a laparotomy; sigmoidoscopy
and/or computed tomography (CT) may be diagnostic ( Chapter
26).
Bloodtests
As stated above, ‘routine labs’ are of minimal value. In addition to
amylase level the only ‘routines’ that can be supported are white cell
count,hematocritandbaselineevaluationofrenalfunction.Anelevated
whitecellcountdenotesaninflammatoryresponse.Beawarethatacute
cholecystitis or acute appendicitis canbe present even when thewhite
cellcountiswithinthenormalrange.Itselevation,however,supportsthe
diagnosis. Many surgeonsare convinced that C-reactive protein (CRP)
levelsaremoresensitiveinthediagnosisofaninflammatoryresponse—
theymayberight.Alowhematocritintheemergencysituationsignifiesa
chronic or subacuteanemia; it poorly reflects on the magnitude of any
acute hemorrhage. However, in patients receiving i.v. fluids, a low
hematocritcommonlyreflectshemodilution.Liverfunctiontestsareof
valueinpatientswithrightupperquadrantpain,diagnosedtohaveacute
cholecystitis(note:liverfunctiontestsmaybenormalornearlynormalin
acute cholecystitis; rely on clinical examination and ultrasound) or
cholangitis ( Chapter 20). Serum albumin on admission is a useful
markerof the severity oftheacute, or acute-on-chronic disease,andis
also of proven prognostic value. When operating, for example, on
someonewithalbuminlevelsof1.5g/dLyouknowthatyouhavetodothe
minimumandtoexpecttroubleaftertheoperation;and,asyouwillhear
repeatedlybelow,toavoidanintestinalanastomosis.
Remember: Whichever tests are ordered, either by you or by someone else on
yourbehalf(usuallytheERdoctor),beawarethatthesignificanceoftheresultsshould
neverbejudgedinisolationbutconsideredaspartofthewholeclinicalpicture.
ChestX-ray(CXR)
ACXRisroutinelyobtainedtosearchforfreeairunderthediaphragm,
asthisis demonstratedinthemajorityof patientswithperforated peptic
ulcer( Chapter18)butlessfrequentlyseenwhencolonicperforationis
theunderlyingproblem.(Withcolonicperforation,theamountoffreeair
seen on an upright CXR can range from none to huge, from a few
bubbles of localized perforation of diverticulitis to the abdominal
ballooning after a colonoscopic tear — Chapter28.) Rememberthat
freeairisbetterseenonanerectCXRthanAXR.Freeintraperitoneal
airisnotalwayscausedbyaperforatedviscusanditisnotalways
anindication for a laparotomy.There is a long list of ‘non-operative’
conditions that may produce free intraperitoneal air, such as a tension
pneumothorax or even vigorous cunnilingus (oral sex). So, don’t
diagnoseinhaste,lookatthewholeclinicalpicture.
Anytextbooktellsyouthatlowerlobepneumoniamaymimicanacute
abdomen,sothinkaboutit.Obviously,findingssuchaslungmetastases
orpleuraleffusionmayhintatthecauseoftheabdominalconditionand
influencetreatment and prognosis.Pneumothorax, pneumomediastinum
or pleural effusion may be associated with spontaneous esophageal
perforation—Boerhaave’ssyndrome( Chapter15),whichcanpresent
as an acute abdomen. The value of a CXR in blunt or penetrating
abdominal injury isobvious — lookat it carefully— a chest tube
inserted before the operation for a small pneumothorax would
prevent a life-threatening tension pneumothorax during the
operation;yousurelyunderstandwhy.Apre-operativeCXRmayalso
be requested by the anesthetists, especially after you have inserted a
centralvenousline,orindeedfornoreasonatall.
Finally, and rarely, be aware that what looks to you on chest
radiography like free air under the right diaphragm is not free air but
bowel(usuallythehepaticflexureofthecolon)interposedbetweenthe
liver and diaphragm. This entity is named afterthe Austrian radiologist
whodescribedit,Dr.Chilaiditi.Ifasymptomaticitistermedthe‘Chilaiditi
sign’.When symptoms areattributedto it (subcostalpain,constipation,
respiratory distress), it becomes the ‘Chilaiditi syndrome’. We have
neverencounteredthis‘syndrome’,butothersclaimanoccasionalneed
for its operative treatment with ‘colopexy’ or colectomy! In uncertain
casesabdominalCTshowsthe‘freeair’tobeinthecolon.
PlainabdominalX-ray(AXR)
Thisisthe classical surgeon’s X-ray, asonlysurgeonsknow the true
value of thesesimple and cheap radiographs. Radiologists can look at
and talk about AXRs forever, searching for findings that could justify
additional imaging studies. We surgeons need only a few seconds to
decide whether the AXR is ‘non-specific’, namely, does not show any
obvious abnormality, orshows an abnormalgaspattern or abnormal
opacities. Unfortunately, in many of today’s ‘modern’ ERs the humble
AXRisbypassedinfavorofthehigh-techCT.Infactnow,formany(but
wehopenotforyou),theCTsupplantsnotonlytheAXRbutalsoproper
historytakingandphysicalexamination.Donotforgetthatweoperate
onpatientsandnotonCTabnormalities.Goto Chapter5toread
aboutAXRsindetail.
Abdominalultrasound(US)
AbdominalUSisareadilyavailablediagnosticmodalityinmostplaces.
Itsreliabilityisoperator-dependent;theidealsituationiswhenthe USis
performedandinterpretedbyanexperiencedclinician—asurgeon.And,
in fact, many European surgeons are trained to use US as part of the
physical examination. US is very accurate in the diagnosis of acute
cholecystitis( Chapter20);itisalso usedby gynecologiststo ruleout
acute pelvic pathology in female patients ( Chapter 35), and to
demonstrateurological pathologies such as hydronephrosis( Chapter
37).Anon-compressibletubularstructure(a‘smallsausage’)intheright
lower quadrant may be diagnostic of acute appendicitis, but as will be
discussedin Chapter23,therearemoreaccuratemodestoreachthis
diagnosis. US is useful in demonstrating intra-abdominal fluid — be it
ascites, pus, or blood, localized or diffuse. In blunt abdominal trauma,
FAST (focused abdominal sonography fortrauma) hasalmost replaced
the use of diagnostic peritoneal lavage. An US-guided aspiration of
unexplainedintraperitonealfluidcanclarifythediagnosis:isitbileorpus
or feces? What is the level of amylase, bilirubin and creatinine in the
fluid? This gives you an idea of what’s going on.And this is ourpolicy
(see Chapter32).
Abdominalcomputedtomography
The use of the CT scanin the acute abdomen remains a subject of
somecontroversy.WhileitistruethataCTscanshouldnotbepartofthe
management algorithm in all patients with acute abdominal pain, the
existingspiralCTtechnologyisneverthelessimmediatelyavailable
andverypowerful.Thetemptationtouseitisstrong,especiallyby
less experienced clinicians, but also by those experienced ones
who wish to achieve an early and accurate diagnosis and avoid
unnecessaryprocedures.
ThemajorroleofCT, whereit canreally makea criticaldifference,is
with‘clinicalpuzzles’.Notinfrequently,thesurgeonencountersapatient
with acute abdominal pain that does not fit any of the clinical patterns
describedin Chapter3.Thepatientisobviouslysick,butthediagnosis
remains elusive. Occasionally there may be a suspicionof acute intraabdominal pathology in an unconscious patient. Under these
circumstances,CTmay beveryhelpfulinidentifying anintra-abdominal
problem. It is even better in excluding the latter by being absolutely
normal—lettingyougohomeandpouraninchorsoontherocks.Know
thefeeling?Finally,theindespensibleroleofCTinabdominaltraumais
discussedlater( Chapter32).
The judicious and selective use of CT may help in avoiding
surgery altogether — where previously ‘negative’, ‘exploratory’ or
‘non-therapeutic’ operations would have been performed. It may
suggestthat alternativepercutaneoustreatment ispossible and,evenif
an operation is still indicated, it may indicate the best incision and
approach( Chapter10).CThasa definiterole inthepost-laparotomy
patient as discussed in Part IV — “After the operation”. For a detailed
discussionontheinterpretationofabdominalCTgoto Chapter5.
Awordofcaution
For most patients with acute abdominal pain, unnecessary ancillary
investigationsaremerelyaresourceproblemandawasteoftime.Butfor
somesurgicalproblems,unnecessaryimagingcanbelethal:
•
Acutemesentericischemiais the only life-threatening abdominal
conditionthatcannotbeeasilyclassifiedintooneofthefiveclinical
patterns described in Chapter3. Because of this, and because
youropportunitytosalvageviablebowelissolimited,youmusthave
this diagnosis constantly embedded in theback of yourmind. The
best chance to salvage these patients is to recognize the clinical
picture of severe abdominal pain withfew objective findingsin the
appropriateclinical context ( Chapter24) and to proceed directly
to ‘CT angio’ (mesenteric angiography). The tragedy in these
patientsistheinabilityofevenanexperiencedcliniciantomakehis
or her mind up regarding the need for urgent imaging of the
mesenteric vasculature. As a result, the opportunity to salvage
viable bowel is lost. So, if you suspect mesenteric ischemia go
directly for a CT angio specifically to assess the patency of the
superiormesentericarteryaswellaslookingforpossiblebowelwall
thickeningorgasbubblesinthebowelwall.Thereisnoneedtowait
fororal contrast to proceed. AlongwithCT angio,measurementof
blood lactate and D-dimer levels are helpful— high lactate levels
suggest ischemic bowel. Normal D-dimer levels speak against
thrombosis,highlevelsmeannothing.
•
Thesecondconditionwherethe abuseof imagingmay belethal is
with a ruptured abdominal aortic aneurysm (AAA) ( Chapter
34). The first scenario occurs in patients with a known aneurysm
presentingwithfeaturesofacuterupturesuchasabdominalorback
pain associated with hypotension who are subjected to an
unnecessaryCTthatmerelydelaysdefinitivetreatment.Thesecond
scenarioarisesasaresultofthefactthataruptured AAAmaynot
present as abdominal pain and shock but merely as severe
abdominal or back pain, and it may not be easily palpable in an
obesepatient.When thepossibilityof acontainedruptureisraised
in a hemodynamically stable patient, the one and only ancillary
investigationthatisrequiredis anurgentCTscanoftheabdomen.
Unfortunately,toomanytimesthesepatientsspendseveralhoursin
the ER, waiting for the results of non-relevant blood tests and
progressing slowly along the imaging path from AXRs, which are
usually non-diagnostic, to US, which shows the aneurysm but
usually cannot diagnosea rupture, to a long wait for unnecessary
contrast material to fill the bowel in preparation for a ‘technically
perfect’ CT scan. The tragic consequence of these delays is a
dramatic hemodynamic collapse either before or during an
abdominalCTscan.
Contraststudies:bariumvs.water-solublecontrast
Acaveat:inemergencysituationsdonotusebarium!Radiologists
prefer barium because of its superior imaging qualities, but for us —
surgeons — barium is an enemy. Bacteria love barium, for it protects
themfromtheperitonealmacrophages;amixtureofbariumwithfecesis
the best experimentalrecipe for the production of intractable peritonitis
and multiple intra-abdominal abscesses. Once barium leaks into the
peritonealcavityitisverydifficulttogetridof.Bariumadministeredtothe
gastrointestinaltractfromaboveorbelowtendstostaytherefordays—
distortingany subsequentCTor arteriography.Andlet usnot forgetthe
rocksitformsintherectumofconstipatedpatients.
A GI contrast study in the emergency situation has only two
queriestoanswer:
•
Istherealeakand,ifso,where?(Pleasenotethattheabsenceof
acontrastleakdoesnotexcludeabowelperforation.)
•
Isthere anobstruction and,ifso, where?(Please note thatCT is
much better and more accurate in defining the obstruction site in
additiontogivingotherusefulinformationabouttheconditionofthe
bowel.)
Forthese purposesGastrografin®is adequate. Use Gastrografin® in
upper gastrointestinal studies to document or exclude gastric outlet
obstruction, treat small bowel obstruction or postoperative ileus (
Chapters21and45)ororderaGastrografin®enematodiagnosecolonic
obstruction or perforation. Unlike barium, Gastrografin® is harmless
shouldit leakinto theperitoneal cavity.Trytooperateonacolonfull of
barium: a clamp slides off, a stapler misfires and you — not the
radiologist—aretheoneleft to clean the s**t. Take some advice from
ourbitter experience:orderingaGastrografin®studyisnotenough;
youmustpersonallyensurethatbariumisnotused.(Thesame,of
course,appliestoanemergencyCT:askforGastrografin®!)
A piece of general advice: do communicate with the radiologists and
radiographers.AsLeoGordonsays:“ThequalityoftheX-rayordered
isdirectlyproportional tothespecificityofthe clinical information
suppliedtotheradiologist.”Talktoyourradiologist,inpersonoronthe
phone; often, once you express your questionsand worries, what was
previouslymissedbecomesobvious!
We simply cannot stand (the word ‘despise’ may not be too strong)
residents,ordoctorsingeneral,whocitefromradiologicalreportswithout
ever seeing themselves the actual iamges. Our method: check the
images first, make a conclusion, and then check to see from the
radiology report if the radiologist agrees with your diagnosis.
Viewing the images together with the radiologist is often a surprisingly
productiveexercise;youcanaccomplishitevenonthephone—eachof
youlookingattheimagesonyoursideofthefiberopticcable.
Unnecessarytests
Dr. Lope Estevez Schwarz of Berlin shared with us this attractive
German phrase: “Wer viel misst, misst viel Mist” — free translation:
peoplewhotesttoomuchtendtogetbullshit...Amen!
Figure4.1.Rationaldiagnosticprocedures.“Boss,getanMRI!”
Unnecessarytestingisplaguingmodernmedicalpractice
( Figure4.1).Lookaroundyouandnoticethatthemajorityofinvestigationsbeingordereddo
not add much to the quality ofcare. Theseunnecessary tests are expensive and potentially
harmful. In addition to the therapeutic delay they may cause, be familiar with the following
paradigm: the more non-indicated tests you order, the more false-positive results are
obtained, which in turn compel you to order more tests and lead to additional,
potentially harmful, diagnostic and therapeutic interventions. Eventually, you lose
control…and,sadly,youcreateVOMIT(victimsofmodernimagingtechnology).
What are the reasons for unnecessary tests? The etiology is a
combination of ignorance, lack of confidence, and laziness. When
abdominal emergencies are initiallyassessed by non-surgeons who do
not ‘understand’ the abdomen, unnecessary imaging is requested to
compensateforignorance.Juniorclinicianswholackconfidencetendto
order tests “just to be sure — not to miss” a rare disorder. And
experienced clinicians occasionally ask for an abdominal CT over the
phoneinordertoprocrastinate.Isn’titeasiertoaskforaCTratherthan
todrive tothe hospitalin themiddleofthenight, orto interruptthe golf
game, and examine the patient? (“Let’s do the CT and decide in the
morning…”).
An occasional surgical trainee finds it difficult to understand “what’s
wrongwithexcessivetesting?”“Well,”weexplain,“Whydoweneedyou
atall?Letusallgohomeinstead,andinstructourERnursestodriveall
patients with abdominal pain througha predeterminedline of tests and
imaging modalities.” But patients are not cars on a production line in
Detroit. They are individuals who need your continuous judgment and
selectiveuseoftests.
Becarefulbeforeadoptinganinvestigationclaimedtobe‘effective’by
others.Youread,forexample,thatinaBostonivorytower,routineCTof
the abdomen has been proven cost-effective in the diagnosis of acute
appendicitis.BeforesuccumbingtothetemptationtoorderaCTforany
suspected acute appendicitis, check whether the methods used in the
originalstudy canbeduplicated inyour own environment.Do youhave
senior radiologists to read the CT at 3 a.m. — or would the CT be
reportedonlyinthemorning—aftertheappendixis,orshouldbe,inthe
formalinjar?
Perhaps the day is near when all patients on their way from the
ambulancetotheERwillbepassedthroughatotalbodyCTscanner—
readbyacomputer.Butthenluckilywewillnotbepracticingsurgeryand
this book will be long out of print. We do not believe, however, that
patientswillfarebetterundersuchasystem.
Believe nobody — question everything… the more the
noise—thelessthefact.
Or,likeLeninsaid:
Trustisgood,controlisbetter.
Diagnosticlaparoscopy
Thisisaninvasivediagnostictool(somecallit“controlledpenetrating
abdominaltrauma”)to beusedintheoperatingroom,afterthe decision
tointervenehasbeenalreadytaken.Ithasaselectiveroleasdiscussed
in Chapter12.Yes,frequently,itistempting“justtohaveapeek”and
solvethediagnosticdilemmas,atthesmallpriceofafewsmallscarsand
theadvantageof avoiding the radiation associatedwithaCT scan. For
some, diagnostic laparoscopy is conceived as an extension of the
imagingeffort,andnotas‘real’surgery.However,weshouldnotforget
thatthisisindeedasurgicalprocedure,forwhichweneedasound
indication. Complications, as well as unnecessary interventions
(likeremovinganormalappendix),arepartofthepackagedeal.
BeforeendingwewishtociteyetagainLeoGordon:“Theemergency
roomisthebestplacetoevaluateanemergency.”Thinkaboutwhat
investigations you wish to order while the patient is still in the ER;
logistically, in most hospitals, it will be moredifficult to obtain all these
testsafterthepatienthasbeenadmitted.
“God gave youears, eyes, and hands; usethem on the
patientinthatorder.”
WilliamKelseyFry
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