Complications of Critical Complications of Critical IllnessIllness

Division of Critical Care Division of Critical Care MedicineMedicine

University of AlbertaUniversity of Alberta

First, do no harm.First, do no harm.

OutlineOutline

Nutritional support in the ICUNutritional support in the ICU Abdominal compartment syndromeAbdominal compartment syndrome DVT/PE in the ICUDVT/PE in the ICU Ventilator associated pneumoniaVentilator associated pneumonia Gastric stress ulcerationGastric stress ulceration

Nutritional Support

Reasons for Support

Limit catabolismLimit catabolism

Substrate for healingSubstrate for healing

Increase survivalIncrease survival

Calculating Metabolic Needs

Formula: Formula: Harris-Benedict EquationHarris-Benedict Equation

Nitrogen BalanceNitrogen Balance

Resting Energy ExpenditureResting Energy Expenditure

Harris-Benedict EquationEstimates Basal Metabolic Rate (BMR):Estimates Basal Metabolic Rate (BMR):

• Male BMR kcal/day = 66.47 + 13.7 (kg) + 5 (cm) - 6.76 (yrs)Male BMR kcal/day = 66.47 + 13.7 (kg) + 5 (cm) - 6.76 (yrs)• Female BMR kcal/day = 66.51 + 9.56 (kg) + 1.85 (cm) - 4.68 Female BMR kcal/day = 66.51 + 9.56 (kg) + 1.85 (cm) - 4.68

(yrs)(yrs)

Total Caloric Requirements equal the B.E.E. Total Caloric Requirements equal the B.E.E. multiplied by the sum of the stress and activity multiplied by the sum of the stress and activity factors. factors.

Stress plus activity factors range from 1.2 to over Stress plus activity factors range from 1.2 to over 2. 2.

Factors to add to the BMR:Factors to add to the BMR:• 25% (25% (mild peritonitis, long bone fracture or mild/moderate mild peritonitis, long bone fracture or mild/moderate

trauma)trauma)• 50% (50% (severe infection, MSOD, severe trauma)severe infection, MSOD, severe trauma)• 100% (100% (burn of 40 to 100% TBSA)burn of 40 to 100% TBSA)

Nitrogen Balance

Measure/estimate all sources of nitrogen output.Measure/estimate all sources of nitrogen output.• stool, urine, skin, fistulae, wounds, etc.stool, urine, skin, fistulae, wounds, etc.

Measure all sources of nitrogen input.Measure all sources of nitrogen input.• enteral or parenteral nutritionenteral or parenteral nutrition

Greenfield 1997

Calculating Nitrogen Balance

Problems with Nutritional Parameters

UUN will be invalid if creatinine clearance is UUN will be invalid if creatinine clearance is less less

than 50.than 50.

UUN and prealbumin are not helpful if the patient UUN and prealbumin are not helpful if the patient

has not received goal volumes of feeding has not received goal volumes of feeding

consistently for three to four days prior to the test.consistently for three to four days prior to the test.

Metabolic CartIndirect Calorimetry: Theory

Measures O2 absorbed in lungsMeasures O2 absorbed in lungs

Assumptions of Fick equation, at steady state O2 Assumptions of Fick equation, at steady state O2 absorbed equals O2 consumed.absorbed equals O2 consumed.

Metabolic rate in cc of O2 per minute.Metabolic rate in cc of O2 per minute.

Conversion 5kcal/liter O2.Conversion 5kcal/liter O2.

24 hour steady state measurement 24 hour steady state measurement recommended.recommended.

Theory - start with a formula, tune it up long-term Theory - start with a formula, tune it up long-term with the metabolic cart!with the metabolic cart!

Metabolic Cart - Indirect Calorimetry: Results

RQ or respiratory quotientRQ or respiratory quotient (CO2 expired/O2 (CO2 expired/O2 inspired).inspired).

0.6 - 0.7 0.6 - 0.7 starvation/underfeedingstarvation/underfeeding

0.84 - 0.860.84 - 0.86 desired range/mixed fuel utilization desired range/mixed fuel utilization

0.9 - 1.00.9 - 1.0 carbohydrate metabolism carbohydrate metabolism

1.0 +1.0 + overfeeding/lipogenesis overfeeding/lipogenesis

Other Clinical Parameters

Wound healing

Measured proteinsMeasured proteins• Albumin (t½ = weeks)Albumin (t½ = weeks)• Prealbumin (t½ = days)Prealbumin (t½ = days)

Non-water weight gainNon-water weight gain

Enteral vs. Parenteral?

Use the GI tract whenever possible.Use the GI tract whenever possible.

Contraindications to GI feeds:Contraindications to GI feeds:• large output fistulalarge output fistula• SBOSBO• severe pancreatitissevere pancreatitis• short gut, severe diarrhea, enteritisshort gut, severe diarrhea, enteritis• non-functional GI tractnon-functional GI tract

Starting Estimates

Determine number of calories needed.Determine number of calories needed.

Determine normal or increased protein needs.Determine normal or increased protein needs.

Determine if contraindication to fats.Determine if contraindication to fats.

Determine fluid restrictions.Determine fluid restrictions.

USE THE GI TRACT IF POSSIBLE!!USE THE GI TRACT IF POSSIBLE!!

NutrientsFatFat - essential linolenic, linoleic, arachidonic acids- essential linolenic, linoleic, arachidonic acids

• 9 kcal/gm9 kcal/gm

ProteinProtein - essential and branched chain AA in TPN- essential and branched chain AA in TPN• 4 kcal/gm - not to be included in calorie estimates4 kcal/gm - not to be included in calorie estimates• no glutamine in TPN due to instabilityno glutamine in TPN due to instability

CarbohydratesCarbohydrates - converted to glucose- converted to glucose• 3.4 kcal/gm (4.0 kcal from endogenous source)3.4 kcal/gm (4.0 kcal from endogenous source)

Trace MineralsTrace Minerals• Chromium, copper, zinc, manganese, selenium, ironChromium, copper, zinc, manganese, selenium, iron

VitaminsVitamins• ThiamineThiamine• FolateFolate• Vitamin CVitamin C

Rules of Thumb: TPN

Want 25 - 35% solution of dextrose.Want 25 - 35% solution of dextrose.

Want 4.25 - 6% AA solution.Want 4.25 - 6% AA solution.• normal 0.8 gm/kg/day up to 2.0 gm/kg/daynormal 0.8 gm/kg/day up to 2.0 gm/kg/day

Kcal/nitrogen ratioKcal/nitrogen ratio• normal 300:1normal 300:1• post-op 150:1post-op 150:1• trauma/sepsis 100:1trauma/sepsis 100:1

Lipids 10 - 20% at least twice per week.Lipids 10 - 20% at least twice per week.

TPN vs. Enteral: Advantages?

Many prospective, randomized studies.Many prospective, randomized studies.TPN group had much higher infection rates.TPN group had much higher infection rates.

pneumonia, intraabdominal abscess, line sepsispneumonia, intraabdominal abscess, line sepsis

• Potential Reasons for TPN Failure:Potential Reasons for TPN Failure:• TPN increases blood glucose if not strictly TPN increases blood glucose if not strictly

controlled.controlled.• numerous studies now show hyperglycemia numerous studies now show hyperglycemia

increases mortality and infectious complications.increases mortality and infectious complications.

• Does not contain glutamine.Does not contain glutamine.

Why Enteral?

Preservation of villous architecturePreservation of villous architecture• may prevent translocationmay prevent translocation• role of translocation unclear in humansrole of translocation unclear in humans• good study in BMT patientsgood study in BMT patients

Ability to give glutamineAbility to give glutamine• major fuel of enterocytesmajor fuel of enterocytes• major nitrogen transfer agent to visceramajor nitrogen transfer agent to viscera• in catabolic stress may be an essential AAin catabolic stress may be an essential AA

Gastric vs. Post-pyloric Feeds

Route probably not important if patient tolerating feeds.Route probably not important if patient tolerating feeds.

If gastric ileus, recent surgery, or need for frequent If gastric ileus, recent surgery, or need for frequent procedures where feeds would be stopped if gastric, procedures where feeds would be stopped if gastric, post-pyloric may be better.post-pyloric may be better.

Refeeding Syndrome

In severely malnourished.In severely malnourished.

Development of severe electrolyte abnormalities:Development of severe electrolyte abnormalities:• phosphorous, potassium, magnesiumphosphorous, potassium, magnesium

As muscle mass, cell mass, and ATP repleted:As muscle mass, cell mass, and ATP repleted:• may reach critically low values, cardiac arrestmay reach critically low values, cardiac arrest

Theoretical Advantages of Early Enteral Nutrition

1. Ameliorate the stress response, hypermetabolism, 1. Ameliorate the stress response, hypermetabolism, and hypercatabolism.and hypercatabolism.

2. Provide gut stimulation to prevent atrophy and the 2. Provide gut stimulation to prevent atrophy and the loss of immunologic and barrier functions of the gut.loss of immunologic and barrier functions of the gut.

3. Minimize rapid onset of acute 3. Minimize rapid onset of acute malnutrition.malnutrition.

4. Decrease LOS and complication rates.4. Decrease LOS and complication rates.

Energy Requirement in Critical Illness: Different

Conditions

Total Kcal Goals

25 - 35 kcal/kg is suitable for most hospitalized 25 - 35 kcal/kg is suitable for most hospitalized patients and is a good rule of thumb.patients and is a good rule of thumb.

21 kcal/kg is appropriate for obese patients.21 kcal/kg is appropriate for obese patients.

30 - 40 kcal/kg may be necessary for highly 30 - 40 kcal/kg may be necessary for highly stressed patients.stressed patients.

Total Protein Goals

1.0 g/kg for healthy individuals.1.0 g/kg for healthy individuals.

1.2 - 1.5 g/kg for mildly stressed.1.2 - 1.5 g/kg for mildly stressed.

1.5 - 2.0 severely stressed/multiple trauma/head 1.5 - 2.0 severely stressed/multiple trauma/head injury/burns.injury/burns.

Lipid Goals

High calorie, low volume.High calorie, low volume.

Suggested max calories - no more than 50% of non-protein Suggested max calories - no more than 50% of non-protein Kcal, or < 1 cal/Kg/hr.Kcal, or < 1 cal/Kg/hr.

Minimum to prevent essential fatty acid deficiency is 2 x Minimum to prevent essential fatty acid deficiency is 2 x 500 cc bottles/week.500 cc bottles/week.

Diprivan (propofol) = 1calorie/mlDiprivan (propofol) = 1calorie/ml

Consequences of Overfeeding

1. 1. AzotemiaAzotemia - patients > 65 years and patients given - patients > 65 years and patients given > 2g/kg protein are at risk.> 2g/kg protein are at risk.

2. 2. Fat-overload syndromeFat-overload syndrome - recommended - recommended maximum is 1g lipid/kg/d. Infuse IV lipid slowly maximum is 1g lipid/kg/d. Infuse IV lipid slowly over 16 - 24 hours.over 16 - 24 hours.

3. 3. Hepatic steatosisHepatic steatosis - patients receiving high - patients receiving high carbohydrate, very low fat TPN are at risk.carbohydrate, very low fat TPN are at risk.

4. 4. HypercapniaHypercapnia -- makes weaning difficult.makes weaning difficult.

5. 5. HyperglycemiaHyperglycemia - increases risk of infection. - increases risk of infection. Glucose should not exceed 5 mg/kg/min (4 Glucose should not exceed 5 mg/kg/min (4 mg/kg/min for diabetics).mg/kg/min for diabetics).

Consequences of Overfeeding

66. . Hypertonic dehydrationHypertonic dehydration - can be caused by high- - can be caused by high-protein formula with inadequate fluid provision.protein formula with inadequate fluid provision.

7. 7. HypertriglyceridemiaHypertriglyceridemia - propofol, high TPN lipid - propofol, high TPN lipid loads, and sepsis increase the risk. If the patient is loads, and sepsis increase the risk. If the patient is hypertriglyceridemic, decrease lipid to an amount to hypertriglyceridemic, decrease lipid to an amount to prevent EFAD (500 cc 10% lipid twice weekly) and prevent EFAD (500 cc 10% lipid twice weekly) and monitor.monitor.

Consequences of Overfeeding

8. 8. Metabolic acidosisMetabolic acidosis - patients receiving low ratios of - patients receiving low ratios of energy to nitrogen are at risk. energy to nitrogen are at risk. Acidosis can cause Acidosis can cause muscle catabolism and muscle catabolism and negative nitrogen balance.negative nitrogen balance.

9. 9. Refeeding syndromeRefeeding syndrome - common in malnourished - common in malnourished patients or those held NPO prior to initiation of patients or those held NPO prior to initiation of feeding. Start feedings conservatively, advance feeding. Start feedings conservatively, advance gradually, and monitor Mg, Ph, and K closely.gradually, and monitor Mg, Ph, and K closely.

Nutritional Goals

Feed as soon as hemodynamically stable, after Feed as soon as hemodynamically stable, after adequate resuscitation.adequate resuscitation.

No disease state improves with starvation. No disease state improves with starvation.

Poor gut perfusion may contraindicate enteral Poor gut perfusion may contraindicate enteral feeds, but enteral feeds are always preferred feeds, but enteral feeds are always preferred when possible. when possible.

Abdominal Compartment Abdominal Compartment SyndromeSyndrome

Abdominal Compartment Syndrome

Acute increase in intra-abdominal pressureAcute increase in intra-abdominal pressure

Affects renal, pulmonary, and cardiovascular Affects renal, pulmonary, and cardiovascular systemssystems

Decreases ventilation, causes hypoxia, decreased Decreases ventilation, causes hypoxia, decreased blood flow to lower extremities, and kidney failure.blood flow to lower extremities, and kidney failure.

Abdominal Compartment Syndrome

Caused by intra-abdominal swelling or hemorrhage.Caused by intra-abdominal swelling or hemorrhage.

Increase in volume of retroperitoneum such as with Increase in volume of retroperitoneum such as with pancreatitis also seen.pancreatitis also seen.

Even reports of retroperitoneal hemorrhage such Even reports of retroperitoneal hemorrhage such as with pelvic fracture or from anticoagulation.as with pelvic fracture or from anticoagulation.

Abdominal Compartment Syndrome

Early recognition and diagnosis vital to prevent complications.Early recognition and diagnosis vital to prevent complications.

Distended, tense abdomen first signDistended, tense abdomen first sign

Bladder pressure confirms elevated pressure and is easy to Bladder pressure confirms elevated pressure and is easy to perform.perform.

Bladder is direct transmitter of pressure at volumes of less than Bladder is direct transmitter of pressure at volumes of less than 100 cc.100 cc.

Bladder Pressure Measurement

Bladder filled with 50 cc. of sterile saline via foley Bladder filled with 50 cc. of sterile saline via foley and pressure monitor connected to side port with and pressure monitor connected to side port with 18 ga. needle.18 ga. needle.

Normal pressure up to 10 cm HNormal pressure up to 10 cm H22OO

Grade I = 10-15Grade I = 10-15

Grade II = 15-25Grade II = 15-25

Grade III = 25-35Grade III = 25-35

Grade IV = >35Grade IV = >35

Abdominal Compartment Syndrome

Grade I-II can be treated with muscle relaxants as Grade I-II can be treated with muscle relaxants as long as clinical situation improves.long as clinical situation improves.

Indication for laparotomy with open abdomen:Indication for laparotomy with open abdomen:

Grade III and over Grade III and over

Failure of improvement with conservative measuresFailure of improvement with conservative measures

Venous Thromboembolism Venous Thromboembolism in ICUin ICU

Importance of DVT Importance of DVT ProphylaxisProphylaxis

Acute DVT/PE preventionAcute DVT/PE prevention

Valvular DamageValvular Damage

Symptomatic proximal DVT can be an extension Symptomatic proximal DVT can be an extension of distal DVT that was previously asymptomatic.of distal DVT that was previously asymptomatic.

Significant number of fatal PE’s Significant number of fatal PE’s NOTNOT preceded preceded by symptomatic DVT.by symptomatic DVT.

Most preventable cause of hospital associated Most preventable cause of hospital associated death in medical patientsdeath in medical patientsPE.PE.

Recurrence

Post-phlebitic syndrome

DVT

PE

Asymptomatic DVT Asymptomatic DVT Upon ICU AdmissionUpon ICU Admission

Patient PopulationPatient Population % DVT% DVT

Surgical ICUSurgical ICU 7.5%7.5%Harris Harris J Vas SurgJ Vas Surg 1997; 26:734-9 1997; 26:734-9

Respiratory ICURespiratory ICU 10.7%10.7%Schonhster Schonhster RespirationRespiration 1998; 65:173-7 1998; 65:173-7

MICU-Resp MICU-Resp fail/ventfail/vent

19%19%Goldberg Goldberg Am J Resp CCMAm J Resp CCM 1996; 1996;

153:A94153:A94

MICU-Resp MICU-Resp fail/ventfail/vent

6.3%6.3%Fraisse Fraisse Am J Resp CCMAm J Resp CCM 2000; 2000;

161:1109-14161:1109-14

Natural History of Natural History of DVTDVT

132 Surgical patients no prophylaxis

56%

No PE (5)

44%

PE (4)

42% Calf only (17)

23% propagation Popliteal/femoral (9)

35% Calf with spontaneous

lysis (14)

30%

DVT (40)

70%

No DVT (92)

Incidence of VTEIncidence of VTEin Major Trauma in Major Trauma WithoutWithout

ProphylaxisProphylaxis

Lower leg DVT 58%, proximal DVT 18%Lower leg DVT 58%, proximal DVT 18%

Vast majority clinically Vast majority clinically notnot apparent. apparent.

Autopsy Studies for PE in Autopsy Studies for PE in Critically Ill PatientsCritically Ill Patients

PE AutopsyPE Autopsy

StudyStudy ICU SettingICU Setting PresentPresent FatalFatal

Neuhaus Neuhaus 19781978

Med/SurgMed/Surg 27%27% 12%12%

Moser 1981Moser 1981 RespiratoryRespiratory 20%20% 0%0%

Pingleton Pingleton 19811981

MedicalMedical 23%23% ----

Cullin 1986Cullin 1986 SurgicalSurgical 10%10% 1%1%

Blosser 1998Blosser 1998 MedicalMedical 7%7% 2%2%

Willemsen Willemsen 20002000

SurgicalSurgical 8%8% 3%3%

Thromboembolism RiskThromboembolism Riskin Surgical Patients - No in Surgical Patients - No

ProphylaxisProphylaxisDVT, %DVT, % PE, %PE, %

CalfCalf ProximalProximal ClinicalClinical FatalFatal

Low RiskLow Risk 2%2% 0.4%0.4% 0.2%0.2% <0.01%<0.01%

Minor Surgery < 40 no risk factorsMinor Surgery < 40 no risk factors

Moderate RiskModerate Risk 10-20 %10-20 % 2-4%2-4% 1-2%1-2% 0.1-0.4%0.1-0.4%

Minor surgery risk factorsMinor surgery risk factors

Surgery 40-60 no risk factorsSurgery 40-60 no risk factors

High RiskHigh Risk 20-40%20-40% 4-8%4-8% 2-4%2-4% 0.4-1.0%0.4-1.0%

Surgery >60, 94 40-60 with additional risk factors (prior VTE, cancer, Surgery >60, 94 40-60 with additional risk factors (prior VTE, cancer, hypercoagulability)hypercoagulability)

Highest RiskHighest Risk 40-80%40-80% 10-20%10-20% 4-10%4-10% 0.2-5%0.2-5%

Surgery with multiple risk factors (age > 40 yr, cancer, prior VTE)Surgery with multiple risk factors (age > 40 yr, cancer, prior VTE)

Hip or knee arthroplasty, HFSHip or knee arthroplasty, HFS

Major trauma, SCIMajor trauma, SCI

Trauma and Venous Trauma and Venous ThromboembolismThromboembolism

Patients recovering from major trauma Patients recovering from major trauma have highest risk for developing VTE have highest risk for developing VTE amongst all hospitalized patients.amongst all hospitalized patients.Without prophylaxis, multisystem or Without prophylaxis, multisystem or major trauma have a DVT risk exceeding major trauma have a DVT risk exceeding 50%. 50%. PE is the third leading cause of death in PE is the third leading cause of death in trauma patients that survive beyond the trauma patients that survive beyond the first day. first day.

Significant Risk Factors and Odds Significant Risk Factors and Odds Ratios for Venous Ratios for Venous ThromboembolismThromboembolism

Risk Factor (Number at Risk)Risk Factor (Number at Risk) Odds Ratio (95% Odds Ratio (95% CI)CI)

*Age *Age 40y (n=178,851) 40y (n=178,851) 2.29 (2.07 – 2.55)2.29 (2.07 – 2.55)

Pelvic fracture (n=2707)Pelvic fracture (n=2707) 2.93 (2.01 – 4.27)2.93 (2.01 – 4.27)

*Lower extremity fracture (n=63,508)*Lower extremity fracture (n=63,508) 3.16 (2.85 – 3.51)3.16 (2.85 – 3.51)

Spinal cord injury with paralysis (n=2852)Spinal cord injury with paralysis (n=2852) 3.39 (2.41 – 4.77)3.39 (2.41 – 4.77)

*Head injury (AIS score *Head injury (AIS score 3) (n=52,197) 3) (n=52,197) 2.59 (2.31 – 2.90)2.59 (2.31 – 2.90)

*Ventilator days > 3 (n=13,037)*Ventilator days > 3 (n=13,037) 10.62 (9.32 – 12.11)10.62 (9.32 – 12.11)

*Venous injury (n=1450)*Venous injury (n=1450) 7.93 (5.83 – 10.78)7.93 (5.83 – 10.78)

Shock on admission (BP<90 mm Hg) Shock on admission (BP<90 mm Hg) (n=18,510)(n=18,510)

1.95 (1.62 – 2.34)1.95 (1.62 – 2.34)

*Major surgical procedure (n=73,974)*Major surgical procedure (n=73,974) 4.32 (3.91 – 4.77)4.32 (3.91 – 4.77)

VTE ProphylaxisVTE Prophylaxis

Pharmacologic

Unfractionated heparin

Low molecular weight heparin

Vit K Antagonists

Mechanical

Graduated Compression Stockings

Intermittent Pneumatic Compression Devices

IVC filters

INJURED PATIENT

High Risk Factors(Odds ratio for VTE = 2 – 3)

• Age 40• Pelvic fx• Lower extremity fx• Shock• Spinal cord injury• Head Injury (AIS 3)

Very High Risk Factors(Odds ratio for VTE = 4 - 10)

• Major operative procedure• Venous injury• Ventilator days > 3 • 2 or more high risk factors

Does the patient have contraindication for Heparin?

Does the patient have contraindication for Heparin?

Yes No

YesNo

Mechanical Compression

LMWH*

* Prophylactic dose

LMWH* and Mechanical

Compression

Mechanical Compression and

serial CFDI OR

Temporary IVC filter

Patient AssessmentPatient Assessment

Mechanical ProphylaxisMechanical Prophylaxis Graduated compression Graduated compression

stockings (GCS)stockings (GCS) Intermittent pneumatic Intermittent pneumatic

compression devices (IPC)compression devices (IPC)

Delayed prophylaxis until high Delayed prophylaxis until high risk bleeding abatesrisk bleeding abates

Screen for proximal DVT with Screen for proximal DVT with Doppler US in high risk patientsDoppler US in high risk patients

Low dose unfractionated Low dose unfractionated heparin (LDUH)heparin (LDUH)Low molecular weight Low molecular weight heparin (LMWH)heparin (LMWH)Combination of LMWH and Combination of LMWH and mechanical prophylaxis for mechanical prophylaxis for high risk patients high risk patients

Assess Bleeding Risk

High Low

Patient AssessmentPatient AssessmentBleedingBleeding

RiskRiskThrombosisThrombosis

RiskRiskProphylaxis Prophylaxis

RecommendationRecommendation

LowLow ModerateModerate LDH 5000 units SC bidLDH 5000 units SC bid

LowLow HighHigh LMWHLMWH DalteparinDalteparin Enoxaparin Enoxaparin

HighHigh ModerateModerate GCS or IPC GCS or IPC LDUH when LDUH when bleeding risk subsidesbleeding risk subsides

HighHigh High High GCS or IPC GCS or IPC LMWH when LMWH when bleeding risk subsidesbleeding risk subsides

Vena Caval FiltersVena Caval Filters5 filter types-all equal efficacy5 filter types-all equal efficacy

Pulmonary embolism 2.6%-3.8%Pulmonary embolism 2.6%-3.8%

Deep Venous Thrombosis 6%-32%Deep Venous Thrombosis 6%-32%

Insertion site thrombosis 23%-36%Insertion site thrombosis 23%-36%

Inferior caval thrombosis 3.6%-Inferior caval thrombosis 3.6%-11.2%11.2%

Postphlebitic syndrome 14%-41%Postphlebitic syndrome 14%-41%

Ventilator Associated Ventilator Associated Pneumonia (VAP)Pneumonia (VAP)

VAP DefinitionVAP Definition

Infection of the lung that occurs 48 Infection of the lung that occurs 48 hours or more after intubation.hours or more after intubation.

Categorized into two groups: Categorized into two groups: Early onset – occurring 48-72 hours after Early onset – occurring 48-72 hours after

intubation.intubation. Late onset – occurring more than 72 Late onset – occurring more than 72

hours after intubation.hours after intubation. Accounts for 47% of all ICU infections.Accounts for 47% of all ICU infections.

VAP Risk FactorsVAP Risk Factors

Age >60Age >60 MaleMale Traumatic injuriesTraumatic injuries Chronic lung diseaseChronic lung disease ARDSARDS Micro aspiration of Micro aspiration of

oropharyngeal oropharyngeal contentscontents

Continuous sedationContinuous sedation

ParalyticsParalytics Nasogastric tubeNasogastric tube Low endotracheal cuff Low endotracheal cuff

pressurepressure Supine head positionSupine head position H2 blockersH2 blockers SinusitisSinusitis Severity of illnessSeverity of illness Duration of ventilationDuration of ventilation

VAP PreventionVAP Prevention

Infection controlInfection control Monitoring pneumonia rates and organism Monitoring pneumonia rates and organism

surveillance lower the overall rate.surveillance lower the overall rate. Strict adherence to hand washing, universal Strict adherence to hand washing, universal

precautions and barrier precautions for precautions and barrier precautions for patients infected or colonized with multidrug-patients infected or colonized with multidrug-resistant bacteria prevent spread of VAP.resistant bacteria prevent spread of VAP.

Noninvasive ventilationNoninvasive ventilation Allows selected patients to preserve normal Allows selected patients to preserve normal

mucociliary defenses.mucociliary defenses.

VAP PreventionVAP Prevention

Patient positioningPatient positioning Lateral rotation of patients while in bed Lateral rotation of patients while in bed

reduces the risk of aspiration.reduces the risk of aspiration. Keeping the head of the bed >30 degrees also Keeping the head of the bed >30 degrees also

reduces the risk of aspiration.reduces the risk of aspiration. Endotracheal cuff pressure and suctioningEndotracheal cuff pressure and suctioning

A persistent endotracheal intracuff pressure of A persistent endotracheal intracuff pressure of <20 cm H2O allows more micro aspiration.<20 cm H2O allows more micro aspiration.

Continuous subglottic suctioning is used to Continuous subglottic suctioning is used to remove the pool of secretions that develops remove the pool of secretions that develops around the endotracheal cuff.around the endotracheal cuff.

VAP PreventionVAP Prevention

Healthcare provider educationHealthcare provider education Ongoing education of hospital staff that Ongoing education of hospital staff that

focuses on semi recumbent positioning, focuses on semi recumbent positioning, avoidance of gastric over distention, avoidance of gastric over distention, appropriate use of sedation, routine oral appropriate use of sedation, routine oral hygiene, and proper endotracheal tube hygiene, and proper endotracheal tube and ventilator circuit management and ventilator circuit management results in a striking decrease in the results in a striking decrease in the incidence of VAP.incidence of VAP.

Gastric Stress UlcersGastric Stress Ulcers

Stress Ulcerations - Stress Ulcerations - DefinitionDefinition

Stress ulcerations are mucosal Stress ulcerations are mucosal erosions that are usually shallow and erosions that are usually shallow and cause oozing from superficial cause oozing from superficial capillary beds.capillary beds.

Deeper lesions can occur and erode Deeper lesions can occur and erode into the submucosa causing massive into the submucosa causing massive hemorrhage or perforation.hemorrhage or perforation.

Most common cause of GI bleeding in Most common cause of GI bleeding in ICU patients.ICU patients.

Stress Ulcerations – Risk Stress Ulcerations – Risk FactorsFactors

There are two major risk factors for There are two major risk factors for clinically significant bleeding due to stress clinically significant bleeding due to stress ulcers: mechanical ventilation more than 48 ulcers: mechanical ventilation more than 48 hours and coagulopathy.hours and coagulopathy.

The risk of clinically important bleeding in The risk of clinically important bleeding in patients without either of these risk factors patients without either of these risk factors was only 0.1%.was only 0.1%.

Burns, renal failure, and head injury are also Burns, renal failure, and head injury are also minor contributors to the risk of bleeding.minor contributors to the risk of bleeding.

Stress Ulceration - Stress Ulceration - PreventionPrevention

H2 blockersH2 blockers Block the stimulatory effects of Block the stimulatory effects of

histamine on parietal cells.histamine on parietal cells. Continuous infusion provides better Continuous infusion provides better

control of gastric pH over bolus infusion control of gastric pH over bolus infusion but is not more protective.but is not more protective.

Also effective if given orally or NG.Also effective if given orally or NG.

Stress Ulceration – Stress Ulceration – PreventionPrevention

Proton pump inhibitorsProton pump inhibitors Mechanism of action is by inactivation of the H-Mechanism of action is by inactivation of the H-

K-ATPase pump.K-ATPase pump. At least equally effective as H2 blockers.At least equally effective as H2 blockers.

NutritionNutrition Several studies have reported that enteral Several studies have reported that enteral

nutrition reduces the risk of bleeding.nutrition reduces the risk of bleeding. This effect is not seen with TPN.This effect is not seen with TPN. If patient is tolerating enteral feeding, then If patient is tolerating enteral feeding, then

additional stress ulceration prophylaxis is additional stress ulceration prophylaxis is unlikely to be needed.unlikely to be needed.

Stress Ulceration – Risk of Stress Ulceration – Risk of VAPVAP

Agents that raise the gastric pH may Agents that raise the gastric pH may promote the growth of bacteria in the promote the growth of bacteria in the stomach.stomach.

These organisms then can reflux These organisms then can reflux back up into the trachea and cause back up into the trachea and cause VAP.VAP.

The jury is still out on the association The jury is still out on the association between acid suppression and VAP between acid suppression and VAP but caution is warranted.but caution is warranted.

SummarySummary

First, do no harmFirst, do no harm Nutritional support in the ICUNutritional support in the ICU Abdominal compartment syndromeAbdominal compartment syndrome DVT/PE in the ICUDVT/PE in the ICU Ventilator associated pneumoniaVentilator associated pneumonia Gastric stress ulcerationGastric stress ulceration