Introduction to Critical CareIntroduction to Critical CareIntroduction to Critical CareIntroduction to Critical Care

Daniel R. Margulies, MD, FACSDaniel R. Margulies, MD, FACSDirector, Trauma and Surgical Critical CareDirector, Trauma and Surgical Critical Care

Department of Surgery, CSMCDepartment of Surgery, CSMC

Daniel R. Margulies, MD, FACSDaniel R. Margulies, MD, FACSDirector, Trauma and Surgical Critical CareDirector, Trauma and Surgical Critical Care

Department of Surgery, CSMCDepartment of Surgery, CSMC

Los Angeles, CaliforniaLos Angeles, CaliforniaLos Angeles, CaliforniaLos Angeles, California

C S

Introduction to Critical Care

What’s so Special about the ICU?

VentilatorsVentilators Hemodynamic MonitoringHemodynamic Monitoring Vasoactive DrugsVasoactive Drugs

““Applied Physiology”Applied Physiology”

Introduction to Critical Care

Basic Ventilator Management Indications for VentilationIndications for Ventilation

Inability to Ventilate (high pCOInability to Ventilate (high pCO22)) COPDCOPD

Inability to Oxygenate (low pOInability to Oxygenate (low pO22)) ARDSARDS

MixedMixed commoncommon

Introduction to Critical Care

OrotrachealOrotracheal NasotrachealNasotracheal CricothyrotomyCricothyrotomy TracheostomyTracheostomy

Intubation

Introduction to Critical Care

Ventilator Orders Initial Ventilator Orders : Volume cycledInitial Ventilator Orders : Volume cycled

FFiiOO22

RateRate Mode (AC, SIMV, PC, PS, CPAP)Mode (AC, SIMV, PC, PS, CPAP) PEEPPEEP TVTV

Consider NG tube, art line, restraintsConsider NG tube, art line, restraints Check the CXR!!Check the CXR!!

Introduction to Critical Care

Ventilator Changes ppO2: O2: keep Fkeep FiiOO22 <60% <60%

PEEPPEEP FFiiOO22

ppCO2CO2

TVTV RateRate

Introduction to Critical Care

Ventilator Changes

pOpO22 = 380 = 380

FFiiOO22=100%=100% What now?What now?

Introduction to Critical Care

Ventilator Changes

Remember the “Rule of 7s”Remember the “Rule of 7s” Each % change of FEach % change of FiiOO22 of 1 results in a of 1 results in a

change of pOchange of pO22 of 7 of 7

pOpO22 - 100 - 100 FFiiOO22 = ------------------- = -------------------

77

Introduction to Critical Care

PaO2 >60 on FiO2 < 0.5 with PEEP <5PaO2 >60 on FiO2 < 0.5 with PEEP <5 Minute vent <10 L/minMinute vent <10 L/min NIF more negative than -20NIF more negative than -20 VC >800 mLVC >800 mL TV >300 mLTV >300 mL Use T-piece or CPAP with PSUse T-piece or CPAP with PS

Weaning

Introduction to Critical Care

Oxygen MaskOxygen Mask Check ABGCheck ABG Cough / Deep BreathingCough / Deep Breathing Incentive SpirometerIncentive Spirometer

After Extubation

Introduction to Critical Care

ARDS

1. Impaired Oxygenation:PaO2/FiO2 ratio < 200 (normal > 450)

2. Bilateral pulmonary infiltrates on CXR

3. PCW < 18 (no CHF)

ARDS is an acute clinical illness characterized by severe hypoxemia and bilateral infiltrates on chest X-ray in the absence of pulmonary edema.

Introduction to Critical Care

•Infection sepsis•Trauma hemorrhagic shock•Multiple transfusions•Low flow state from any cause•Aspiration pneumonia•Acute pancreatitis•Smoke inhalation•and many more…..

Causes

Introduction to Critical Care

Levy G, Shabot MM, Hart M, et al: Transfusion associated non-cardiogenic pulmonary edema. Transfusion 1986;26: 278.Levy G, Shabot MM, Hart M, et al: Transfusion associated non-cardiogenic pulmonary edema. Transfusion 1986;26: 278.

Introduction to Critical Care

Pathophysiology

• Large alveolar surface area = 70 m2 (skin =

1.7 m2)

• Lung sensitive to noxious stimuli - inhaled and circulating

• Lung receives entire cardiac output every minute

• Affected by multiple inflammatory mediators and cells

Introduction to Critical Care

• Thromboxane A2

• Prostacyclin

• Leukotrienes

• Platelet-activating factor (PAF)

• Bradykinin

• C3a, C5a

• Tumor necrosis factor

• IL-1, IL-6

• Elastase, Collagenase

• Oxygen free radicalsNothing New…...Still can’t do anything about ‘em!

• Leucocytes

• Macrophages

• Monocytes

• Endothelial cells

• Mast cells

• Bosophils

• Fibroblasts

• Platelets

Inflammatory Mediators Cells

Introduction to Critical Care

Causes & Time of Death After Multiple Trauma

Introduction to Critical Care

Goal: Reduce Alveolar distention

Marcy & Marini. Chest 1991;100:494

New Ventilator Strategies - I

Introduction to Critical Care

• Pressure controlled ventilation

• Pressure release ventilation

• Low volume pressure-limited ventilation

• Inverse ratio ventilation

• Prone ventilation

New Ventilator Strategies

• Permissive hypercapnia

Introduction to Critical Care

Permissive Hypercapnia

Tolerate mild to moderate respiratory acidosis (elevated PCO2) in order to reduce airway pressures.

• Lower tidal volumes

• Lower respiratory rates

• Lower peak and mean airway pressures

Introduction to Critical Care

Prone Positioning

Stocker et al. Chest 1997;111:1008

Introduction to Critical Care

Extracorporeal CO2 Removal (ECCO2R)

Guinard et al. Clin Invest Crit Care 1997;111:1000

Status: Ineffective

Introduction to Critical Care

• Extra-corporeal membrane oxygenation (ECMO)

Other New Ventilator Strategies

• High frequency ventilation (>60/min)

• High Positive End-Expiratory Pressure (PEEP) ventilation

• Extra-Corporeal CO2 Removal (ECCOR)

• Partial Liquid Ventilation

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Introduction to Critical Care

Partial Liquid Ventilation

Leach et al. Crit Care Med 1993;21:1270.

Introduction to Critical Care

Partial Liquid Ventilation

Partial Liquid VentConventional Vent

PaO2

PaCO2

pH

Status: Unproven

Introduction to Critical Care

• Surfactant replacement

• Ketoconazole

• Prostaglandin E1

• Non-steroidal anti-inflammatory agents

• High dose steroids (again)

New Pharmacologic Strategies

• Inhaled nitric oxide (NO)

Introduction to Critical Care

Pharmacologic Treatment of ARDS

Kollef & Schuster. NEJM 1995;332:27.

Introduction to Critical Care

How the SICU Does It

• 31 y/o female

• 2 days S/P laparoscopic GYN procedure

• Found hypotensive, febrile on ward

• CT abdomen - fluid collections & air

• OR SB perf + massive contamination

• SICU postop - hypotensive on vent

Patient R.N.

Introduction to Critical Care

4/5

Introduction to Critical Care

4/11

Introduction to Critical Care

• Hemodynamic/Swan-Ganz monitoring

• Volume resuscitation > 20L (sepsis)

• Triple antibiotics

• Dopamine, neosynepherine

• CT guided abscess drainage

• Repeat laparotomy & drainage

Surgical ICU Management

Introduction to Critical Care

4/13/

Introduction to Critical Care

Ventilator Management

• A/C volume vent Pressure Control vent

• Inverse Ratio ventilation

• Paralysis & sedation > 10 days

• Permissive hypercapnia

• High PEEP (as required) 15 cm H2O

• High FiO2 (as required) 100% ~ 7 days

• Tracheostomy

Introduction to Critical Care

4/20

Introduction to Critical Care

ARDS Management Principles

Brandstetter RD. Heart Lung 1997;26: 3-14

?

Introduction to Critical Care

ARDS Prognosis - Overall

Milberg at al. JAMA 1995;273:306.

Introduction to Critical Care

The good news is…….

The bad news is…….

The prognosis and survival for ARDS is improving!

WE’RE NOT EXACTLYSURE WHY!

The News on ARDS in Summary

Introduction to Critical Care

Hemodynamic Monitoring and Vasoactive Drugs

Introduction to Critical Care

SHOCK

A state in which tissue perfusion and/or A state in which tissue perfusion and/or nutrient uptake fails to meet the body's nutrient uptake fails to meet the body's metabolic needs. Shock can occur with low, metabolic needs. Shock can occur with low, high or normal cardiac output.high or normal cardiac output.

CardiogenicCardiogenic HypovolemicHypovolemic SepticSeptic NeurogenicNeurogenic Cardiac compressiveCardiac compressive

Introduction to Critical Care

CONTROL OF CARDIAC OUTPUT

PRELOADPRELOAD left ventricular end diastolic pressureleft ventricular end diastolic pressure

AFTERLOADAFTERLOAD pressure against which the left ventriclepressure against which the left ventricle must eject bloodmust eject blood

HEART RATEHEART RATE

CONTRACTILITYCONTRACTILITY strength of left ventricular contractionstrength of left ventricular contraction

Introduction to Critical Care

CONTROL OF CARDIAC OUTPUT

Introduction to Critical Care

Pulmonary Artery Catheter

Introduction to Critical Care

Starling Curves

Introduction to Critical Care

Catheter Insertion Waveforms

Introduction to Critical Care

CONTROL OF CARDIAC OUTPUT

Introduction to Critical Care

CONTROL OF CARDIAC OUTPUT

• Normal Hemodynamic Parameters :

• MAP - 70-110 mmHg

• SVR - 900-1200 dynes/cm square

• PVR - 80-120 dynes/cm square

• CO - 4-7 L/min

Introduction to Critical Care

CONTROL OF CARDIAC OUTPUT

• Normal Hemodynamic Parameters :

• DO2 - 700-1400 ml/O2/square meter

• VO2 - 180-280 ml/O2/square meter

• O2 extraction - 20-30%

• Qs/Qt - 3-5%

• Ca O2 - 16-22 vol%

• Cv O2 - 12-16 vol%

Introduction to Critical Care

Hemodynamic Parameters

SVR = ( MAP - RAp/ CO ) x 80 - systemic vascular resistance

PVR = ( PAP - PAOP/ CO ) x 80 - pulmonary vascular resistance

CO = VO2 / ( CaO2 - CvO2 ) - cardiac output

DO2 = CO x Ca O2 x 10 - Oxygen delivery

MAP = mean arterial pressure, PAP = pulmonary artery pressure, RAp = central venous pressure ( RA pressure ), PAOP = pulmonary artery occlusion pressure )

Introduction to Critical Care

Hemodynamic Parameters

VO2 = ( Ca O2 - Cv O2 ) x CO x10 - Oxygen consumption

Ca O2 = ( 1.39 x Hb x SaO2 ) + ( 0.003 x PaO2 ) - Arterial O2 content

Cv O2 = ( 1.39 x Hb x SvO2 ) + ( 0.003 x PvO2 ) - Venous O2 content

•O2 extraction = VO2 / DO2

•Qs/Qt = ( PA-a O2 ) / ( PA-a O2 ) / ( Ca-v O2 ) - Shunt fraction

Pa O2 = partial arterial oxygen pressure.

Introduction to Critical Care

Intensive Care Medicine

VentilatorsVentilators ARDSARDS

Hemodynamic MonitoringHemodynamic Monitoring Vasoactive DrugsVasoactive Drugs