Aspiration Pneumonia Aspiration Pneumonia by by Dr.jarahzadeh Dr.jarahzadeh Intensivist Intensivist.
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Transcript of Aspiration Pneumonia Aspiration Pneumonia by by Dr.jarahzadeh Dr.jarahzadeh Intensivist Intensivist.
Aspiration Aspiration PneumoniaPneumonia
byby
Dr.jarahzadehDr.jarahzadeh
IntensivistIntensivist
Aspiration Aspiration
DefinitionDefinition– Misdirection of gastric contents into Misdirection of gastric contents into
the larynx resulting from alteration the larynx resulting from alteration in lower airway defenses such as in lower airway defenses such as glottic closure and the cough reflexglottic closure and the cough reflex
IncidenceIncidence
Half of all adults aspirate small Half of all adults aspirate small amounts of oropharyngeal amounts of oropharyngeal contents in their sleepcontents in their sleep
Aspiration may occur in up to Aspiration may occur in up to 10% of nursing home residents 10% of nursing home residents annuallyannually
Risk aspirationRisk aspiration
The risk of aspiration with modern anesthesia is about 1 in 3,000 anesthetics, with a mortality of approximately 1: 125,000,accounting for between 10% to 30% of all anesthetic deaths.
The risk of aspiration is greatly increased inpatients intubated emergently in the field emergency department, or ICU.
Reduce the risk of Reduce the risk of aspiration in ETT aspiration in ETT intubationintubation
removing dentures removing dentures clearing the airway clearing the airway in certain circumstances placing a in certain circumstances placing a
nasogastric tube to empty the nasogastric tube to empty the Stomach before intubation.Stomach before intubation.
*If there is an immediate risk of airway compromise, endotracheal intubation should be performed before placement of a nasogastric tube.
clearing the airwayclearing the airway
Predisposing FactorsPredisposing Factors
Decreased consciousnessDecreased consciousness– AlcoholAlcohol– DrugsDrugs– Hepatic failureHepatic failure– CVACVA– AnesthesiaAnesthesia
Predisposing FactorsPredisposing Factors
Esophageal disordersEsophageal disorders– GERDGERD– StrictureStricture– Tracheoesophageal fistulaTracheoesophageal fistula– Incompetent cardiac sphincterIncompetent cardiac sphincter– Protracted vomitingProtracted vomiting
Predisposing FactorsPredisposing Factors
Disruption of glottic closureDisruption of glottic closure– Endotracheal intubationEndotracheal intubation– NG tubeNG tube– Endoscopy/bronchoscopyEndoscopy/bronchoscopy
Predisposing FactorsPredisposing Factors
Neuromuscular disordersNeuromuscular disorders– Multiple sclerosisMultiple sclerosis– Parkinson’sParkinson’s– Myasthenia gravisMyasthenia gravis
Aspiration Aspiration PneumonitisPneumonitis
Mendelson first described Mendelson first described aspiration pneumonitis in 1946aspiration pneumonitis in 1946– 44016 (po-obstetric patien-half resive 44016 (po-obstetric patien-half resive
anesthesia with mask ) 66 patients anesthesia with mask ) 66 patients aspirated gastric contents after ether aspirated gastric contents after ether anesthesiaanesthesia..
All patients had recovery within 2 All patients had recovery within 2 daysdays
Aspiration Aspiration PneumonitisPneumonitis
Definition Definition Acute lung injury Acute lung injury following the following the
aspiration of regurgitated gastric aspiration of regurgitated gastric contents and results in a chemical contents and results in a chemical burn of the tracheobronchial tree burn of the tracheobronchial tree and pulmonary parenchyma with an and pulmonary parenchyma with an intense parenchymal inflammatory intense parenchymal inflammatory reactionreaction
chemical Pneumonitischemical Pneumonitis
PathophysiologyPathophysiology– Animal models demonstrate that Animal models demonstrate that
clinically significant pneumonitis clinically significant pneumonitis results from aspirating at least results from aspirating at least 1ml/kg of pH<2.5 gastric contents1ml/kg of pH<2.5 gastric contents
– Fluids that are not harmful to the Fluids that are not harmful to the airwayairway Water, saline, barium, gastric contents Water, saline, barium, gastric contents
with pH>2.5with pH>2.5
Experimental studies have shown a biphasic pattern of lung injury after acid aspiration. The first phase peaks at ! to2 hours after aspiration and presumably results from thedirect caustic effect of the low pH on the alveolar-capillarywall lining cells. The second phase, which peaks at 4 to 6 hours, is associated with infiltration of neutrophils into the alveoli and lung interstitium with a histologic picture ofacute inflammation.
PathophysiologyPathophysiology
Chemical PneumonitisChemical Pneumonitis
Clinical featuresClinical features– Abrupt onset of dyspneaAbrupt onset of dyspnea– Low grade feverLow grade fever– Pink frothy sputumPink frothy sputum– Diffuse crackles on examDiffuse crackles on exam– CXR: diffuse infiltratesCXR: diffuse infiltrates
Chemical PneumonitisChemical Pneumonitis
Xray of chemical Xray of chemical pneumonitis 2 hours pneumonitis 2 hours after aspiration eventafter aspiration event
Chemical PneumonitisChemical Pneumonitis
TreatmentTreatment– Ventilatory support may be Ventilatory support may be
necessarynecessary– Corticosteriods: beneficial in animal Corticosteriods: beneficial in animal
models, unsuccessful in humansmodels, unsuccessful in humans– AntibioticsAntibiotics
Up to 25% of patients have bacterial Up to 25% of patients have bacterial superinfection (Dines et al)superinfection (Dines et al)
Bacterial PneumonitisBacterial Pneumonitis
Clinical featuresClinical features– Much more insidious onset than Much more insidious onset than
chemical pneumonitis (days to weeks)chemical pneumonitis (days to weeks)– CoughCough– FeverFever– Purulent sputumPurulent sputum– CXR: Infiltrate frequently in dependent CXR: Infiltrate frequently in dependent
segmentssegments
Bacterial PneumonitisBacterial Pneumonitis
Patient aspirate in the recumbent position the most commonsites of involvement are the posterior segments of the upperlobes and the apical segments of the lower lobes.
patient aspirate in the upright or semi-recumbent position thebasal segments of the lower lobes are favored.
Bacterial PneumonitisBacterial Pneumonitis
Xray of bacterial aspiration pneumoniaXray of bacterial aspiration pneumonia
Bacterial PneumonitisBacterial Pneumonitis
Bacterial PneumonitisBacterial Pneumonitis
MicrobiologyMicrobiology– AnaerobesAnaerobes
PeptostreptococcusPeptostreptococcus FusobacteriumFusobacterium BacteroidesBacteroides
– Gram negative bacilliGram negative bacilli Klebsiella in alcoholicsKlebsiella in alcoholics E coli, serratia, proteusE coli, serratia, proteus
– Gram positive bacteriaGram positive bacteria Staph, Hemophilus, streptococcusStaph, Hemophilus, streptococcus
Bacterial PneumonitisBacterial Pneumonitis
TreatmentTreatment The choice of antibiotics shouldThe choice of antibiotics should
depend on the setting in which the depend on the setting in which the aspiration occurs aspiration occurs (home,nursing (home,nursing home,hospital)home,hospital)or premorbid or premorbid condition.condition.
Bacterial PneumonitisBacterial Pneumonitis
Antimicrobial agents withgram-negative activity such as fluoroquinolones, thirdgeneration cephalosporins, piperacillin, or a carbapenem are usually required.
Antimicrobials with specific anaerobicactivity are not routinely warranted and may be indicatedonly in patients with severe periodontal disease, patientsexpectorating putrid sputum, and patients with a necrotizing pneumonia or lung abscess
Bacterial PneumonitisBacterial Pneumonitis
All elderly patients with CAP and all patients with aspirationpneumonia require consultation by a speech and languagepathologist to assess for the presence of dysphagia
Solid Particle Solid Particle AspirationAspiration
Large particlesLarge particles– Sudden respiratory distress, Sudden respiratory distress,
cyanosis, aphoniacyanosis, aphonia Heimlich!Heimlich!
Small particlesSmall particles– Irritative cough, unilateral wheezingIrritative cough, unilateral wheezing
Remember: bacterial superinfection is Remember: bacterial superinfection is commoncommon
Assessment of Assessment of DysphagiaDysphagia Clinical signs of dysphagiaClinical signs of dysphagia
– DroolingDrooling– Coughing before, during, or after Coughing before, during, or after
swallowswallow– Multiple swallows per mouthfulMultiple swallows per mouthful– Unusual head posturing while Unusual head posturing while
swallowingswallowing Clinical exam for diagnosisClinical exam for diagnosis
– Sensitivity 80%, Specificity 70%Sensitivity 80%, Specificity 70%
Assessment of Assessment of DysphagiaDysphagia
Modified barium swallow Modified barium swallow (MBS)(MBS)Patients swallow small amounts of different Patients swallow small amounts of different
textured barium and evaluated by textured barium and evaluated by flouroscopyflouroscopy
– One study demonstrated that MBS did not One study demonstrated that MBS did not change the sensitivity of clinical exam, but change the sensitivity of clinical exam, but did make the evaluation more specificdid make the evaluation more specific
Laryngoscopy
Modified Barium Modified Barium SwallowSwallow
Stasis of contrast at the level of the pyriform sinuses (blue arrows) with subsequent aspiration (yellow arrows)
Tube FeedingTube Feeding
Short term dysphagiaShort term dysphagia– In moderately disabled CVA patients In moderately disabled CVA patients
with dysphagia, tube feeding has with dysphagia, tube feeding has been shown to be associated with been shown to be associated with less pneumonia than oral feeds less pneumonia than oral feeds (54% vs. 13%, p<0.001) for stroke (54% vs. 13%, p<0.001) for stroke patients with dysphagia (Nakajoh)patients with dysphagia (Nakajoh)
PreventionPrevention
HOB elevated 30-45 degreesHOB elevated 30-45 degrees Oral decontamination with Oral decontamination with
chlorhexidinechlorhexidine Chin down - helps to narrow the airwayChin down - helps to narrow the airway Head tilt to stronger side when Head tilt to stronger side when
swallowingswallowing
PreventionPrevention
*Substance P*Substance PBelieved to play a major role in the coughBelieved to play a major role in the cough
and swallow sensory pathways and swallow sensory pathways
*ACE*ACE inhibitorsinhibitors prevent prevent breakdown of substance Pbreakdown of substance P
576 elderly patients with HTN: 3% 576 elderly patients with HTN: 3% pneumonia in those treated with ACEI pneumonia in those treated with ACEI vs. 9% in those treated with Ca channel vs. 9% in those treated with Ca channel blocker.blocker.
ReferencesReferences
Haruka Tohara, Eiichi Saitoh, Keith A. Mays, Keith Kuhlemeier and Jeffrey B. Palmer; Three Tests for Predicting Aspiration without Videofluorography; Dysphagia. 2003 Spring;18(2):126-34
Li, I. Feeding tubes in patients with severe dementia. American Family Physician. 2002 Apr 15;65(8):1605-10, 1515
Marek, PE. Aspiration pneumonia and dysphagia in the elderly. Chest. 2003 Jul;124(1):328-36
Paintal, HS. Kuschner, WG. Aspiration syndromes: 10 clinical pearls every physician should know. Int J Clinical Practice.2007 May;61(5):846-52.
Uptodate
www.radiologyassistant.nl/en/440bca82f1b77
Fink(critical care medicine)
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