ARDS in Trauma

Karl Wagner MD

11/30/04

30 y/o male(note eyes covered to protect identity)

2 Dudes(Probably these two)

H&P

CC: s/p MVA

HPI: pt 30y/o male in comes to the ED after an MVA with multiple injuries

PMHx/PSHx: insignificant

Meds: none

Allergies: none

Physcical ExamBP 110/85, HR 115, RR 32Neuro: in C-collar, GCS 10 (E3V3M4)CVS: tachycardic, Resp/chest: dyspnea, tachypneic, tenderness on right chest, CTA bilat, decreased inspiratory excursionABD: nondistended, soft, tender in right upper quadrantEXT: 18g IV in left AC and 16g IV right AC, moves all 4 ext, deformity of left thigh, tender to palpation, pulses intact

Glasgow Coma Scale

Eyes spontaneous, command, pain, none

Verbal oriented, confused, inappropriate, inconprehensible, none

Motor obeys, localizes, withdraws, flex, extension, none

Physcical ExamBP 110/85, HR 115, RR 32Neuro: in C-collar, GCS 10 (E3V3M4)CVS: tachycardic, Resp/chest: dyspnea, tachypneic, tenderness on right chest, CTA bilat, decreased inspiratory excursionABD: nondistended, soft, tender in right upper quadrantEXT: 18g IV in left AC and 16g IV right AC, moves all 4 ext, deformity of left thigh, tender to palpation, pulses intact

Injury Survey

Small subdural hematoma over right frontal lobe

Right sided rib fractures 5-8

Lung contusion

Liver contusion

Left femur fracture

Operating Room

Ventilator 10 cc/kg, 10 Resp/min

Isoflurane

Arterial line and introducer

Four units packed red blood cells

Conservative mx for liver

Off to SICU for continued mx

All in a days work

Lung Injury

Range of entities

Local not clinically significant

Unable to exchange gases across mebranes and participate in respiration

Somewhere in between

Inflammation

Blunt injury

Neutrophiles

Cytokines

Macrophages

Complement Cascade

Coagulation Cascade

Normal Lung Tissue

Exudative Phase

Starts early.

Interstitial and alveolar edema

Hyaline membrane formation

Endothelial cell damage

Type I cell necrosis

Infiltration with neutrophiles

Diffuse Alvolar Damage

Proliferation Phase

Type II cells increase in number

Type II cells can become Type I cells

Fibrotic Stage

Fibroblasts

Myofibroblasts

Collagenation

Arteriolar hypertrophy

Obliteration of pulmonary vasculature

Late Diffuse Alveolar Damage

Neutrophiles

Already there…

Secrete toxins…

Connected for activation…

Protected from deactivation…

Location, Location, Location…

Map to the Neighborhood

Macrophages

Killing machines

Keep going and going and going…

Complement

IL-1, -6, -8

TNF

Impaired judgment?

Endothelium

Express cytokines

Secrete vasoactive substance

Procoagulant

Metabolically active

Phospholipids

On all cells

Great cellular messenger

Makes more cellular messengers

Arachadonic acid

Thromboxane

Prostacylin

PAF

Pulmonary Edema

Hydrostatic pressure

Oncotic pressure

Lymph system

Increase distance from capillary lumen to alveolar lumen

Pulmonary hypertension

Hypoxemia

Lung compliance decreases

Diffuse Alveolar Infultrates

Patchy Densities

Phase 1

Dyspnea

Tachypnea

Normal CXR

Hypoxemia

Hypocarbia

Neutrophiles

Phase 2

Changes on CXR

Changes on PE

Pulmonary Hypertension

Change in pulmonary mechanics

Microscopic lung changes/damage

Phase 3

Worse CXR

Worse PE

Worse cardiopulmonary mechanics

Decreased hemoglobin oxygen extraction

Occlusion of vessels

Phase 4

Diffuse infiltrates with superimposed pneumonia

Sepsis

MOF

More lung impairment

Cellular changes in the lung

Diagnosis of ARDS

Diffuse alveolar infiltrates on CXR

Noncardiogenic pulmonary edema

PaO2/FiO2 ratio <200

12-39% Trauma Population

Mortality 25-30%

Risk FactorsShock

Gastric aspiration

Pulmonary contusion

Near-drowning

Fractures

Smoke inhalation

Multiple transfusions

Fat embolism

Pneumonia

SepsisInjury severity score > 16Blunt injuryTrauma score < 13Surgery to head+/- admission lactate, pH, base deficit, serum bicarbonateDisseminated intravascular coagulation

Injury Severity Score

Head and Neck

Face

Chest

Abdomen

Extremity

External

Trauma Score

Glasgow Coma Scale

Systolic Blood Pressure

Respiratory Rate

Strategy

Spontaneous respiration

Noninvasive positive pressure

Beware oxygen toxicity

Fluid balance

Treat underlying causes

Ventilator Strategies

High PEEP early – 16 cm H2O

Watch plateau pressure <35 cm H2O

Low tidal volume – 6-8 cc/kg

Be careful with manual ventilation

Hypercapnia

Pressure controlled ventilation

For Longer Term Care

Treat underlying infections

Proning

ECMO

Trach ‘em early

NO!

Steroids?

BibliographyAmato MBP, Barbas CSV, Medeiros DM, et al: Effect of a protective ventilation strategy on mortality in the acute respiratory distress syndrome. NEJM 1998; 338: 347 354The Acute Respiratory Distress Syndrome Network: Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. NEJM 2000; 342.M McCunn, MD, MIPP, A Sutcliffe, MBChB, W Mauritz, MD, PhD and the ITACCS Critical Care Committee: Guidelines for Management of Mechanical Ventilation for Critically Injured Patients.

Bibliography continuedPEEP in ARDS – How much is enough? Levy M. M. N Engl J Med 2004; 351:389-391, Jul 22, 2004

 Medical Progress: The Acute Respiratory Distress Syndrome. Kollef M. H., Schuster D. P. N Engl J Med 1995; 332:27-37, Jan 5, 1995.

 Higher versus lower positive end-expiratory pressures in patients with the acute respiratory distress syndrome. The National Heart, Lung, and Blood Institute ARDS clinical Trials Network. N Engl J Med 2004; 351: 327-336, Jul 22, 200

More BibliographyMedical Progress: The Acute Respiratory Distress Syndrome. Ware L. B., Matthay M. A. N Engl J Med 2000; 342:1334-1349, May 4, 2000.  Effect of age on the development of ARDS in trauma patients.

Johnston CJ - Chest - 01-AUG-2003; 124(2): 653-9 Glucocorticoids and acute lung injury.Thompson BT - Crit Care Med - 01-APR-2003; 31(4 Suppl): S253-7 Effect of acute lung injury and acute respiratory distress syndrome on outcome in critically ill trauma patients.

Treggiari MM - Crit Care Med - 01-FEB-2004; 32(2): 327-31

Bibliography ContinuedManagement of post traumatic respiratory failure.Michaels AJ - Crit Care Clin - 01-JAN-2004; 20(1): 83-99, vi – viiMatox, Feliciano, Moore. Trauma Fouth Edition. McGraw-Hill 2000. Pages 1309-1339.Beers and Berkow. The Merck Manual of Diagnosis and Therapy Seventeenth Edition. Merck and Co. 1999. Pages 551-555.Fauci et al. Harrison’s Principles of Internal Medicine Fourteenth Edition. McGraw-Hill 1998. Pages 1483-1490.

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Thanks for a fun morning!