Introduction to Critical Care Daniel R. Margulies, MD, FACS Director, Trauma and Surgical Critical Care Department of Surgery, CSMC Daniel R. Margulies, MD, FACS Director, Trauma and Surgical Critical Care Department of Surgery, CSMC Los Angeles, California C S

Introduction to Critical Care What’s so Special about the ICU? n Ventilators n Hemodynamic Monitoring n Vasoactive Drugs “Applied Physiology”

Introduction to Critical Care Basic Ventilator Management n Indications for Ventilation u Inability to Ventilate (high pCO 2 ) F COPD u Inability to Oxygenate (low pO 2 ) F ARDS u Mixed F common

Introduction to Critical Care n Orotracheal n Nasotracheal n Cricothyrotomy n Tracheostomy Intubation

Introduction to Critical Care Ventilator Orders n Initial Ventilator Orders : Volume cycled u F i O 2 u Rate u Mode (AC, SIMV, PC, PS, CPAP) u PEEP u TV n Consider NG tube, art line, restraints n Check the CXR!!

Introduction to Critical Care Ventilator Changes n p O2: keep F i O 2 <60% u PEEP u F i O 2 n p CO2 u TV u Rate

Introduction to Critical Care Ventilator Changes n pO 2 = 380 n F i O 2 =100% n What now?

Introduction to Critical Care Ventilator Changes n Remember the “Rule of 7s” n Each % change of F i O 2 of 1 results in a change of pO 2 of 7 pO n  F i O 2 =

Introduction to Critical Care n PaO2 >60 on FiO2 60 on FiO2 < 0.5 with PEEP <5 n Minute vent <10 L/min n NIF more negative than -20 n VC >800 mL n TV >300 mL n Use T-piece or CPAP with PS Weaning

Introduction to Critical Care n Oxygen Mask n Check ABG n Cough / Deep Breathing n Incentive Spirometer After Extubation

Introduction to Critical Care ARDS 1. Impaired Oxygenation: PaO2/FiO2 ratio 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.

Introduction to Critical Care Pathophysiology Large alveolar surface area = 70 m 2 (skin = 1.7 m 2 ) 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 radicals Nothing 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 P CO2 ) 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     ?

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.

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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

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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

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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 EXACTLY SURE 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 nutrient uptake fails to meet the body's metabolic needs. Shock can occur with low, high or normal cardiac output. F Cardiogenic F Hypovolemic F Septic F Neurogenic F Cardiac compressive

Introduction to Critical Care CONTROL OF CARDIAC OUTPUT l PRELOAD n left ventricular end diastolic pressure l AFTERLOAD n pressure against which the left ventricle n must eject blood l HEART RATE l CONTRACTILITY n strength 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 mmHg SVR dynes/cm square PVR dynes/cm square CO L/min

Introduction to Critical Care CONTROL OF CARDIAC OUTPUT Normal Hemodynamic Parameters : DO ml/O2/square meter VO ml/O2/square meter O2 extraction % Qs/Qt - 3-5% Ca O vol% Cv O 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 ) + ( x PaO2 ) - Arterial O2 content Cv O2 = ( 1.39 x Hb x SvO2 ) + ( 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 n Ventilators u ARDS n Hemodynamic Monitoring n Vasoactive Drugs