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
?
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