CONTROL OF CARDIAC OUTPUT

1
Introduction to Critical Care
2
Whats so Special about the ICU?

• Ventilators
• Hemodynamic Monitoring
• Vasoactive Drugs
• Applied Physiology

3
Basic Ventilator Management

• Indications for Ventilation
• Inability to Ventilate (high pCO2)
• COPD
• Inability to Oxygenate (low pO2)
• ARDS
• Mixed
• common

4
Intubation

• Orotracheal
• Nasotracheal
• Cricothyrotomy
• Tracheostomy

5
Ventilator Orders

• Initial Ventilator Orders Volume cycled
• FiO2
• Rate
• Mode (AC, SIMV, PC, PS, CPAP)
• PEEP
• TV
• Consider NG tube, art line, restraints
• Check the CXR!!

6
Ventilator Changes

• pO2 keep FiO2 lt60
• PEEP
• FiO2
• pCO2
• TV
• Rate

7
Ventilator Changes

• pO2 380
• FiO2100
• What now?

8
Ventilator Changes

• Remember the Rule of 7s
• Each change of FiO2 of 1 results in a change of
  pO2 of 7
• pO2 - 100
• ? FiO2 -------------------
• 7

9
Weaning

• PaO2 gt60 on FiO2 lt 0.5 with PEEP lt5
• Minute vent lt10 L/min
• NIF more negative than -20
• VC gt800 mL
• TV gt300 mL
• Use T-piece or CPAP with PS

10

After Extubation

• Oxygen Mask
• Check ABG
• Cough / Deep Breathing
• Incentive Spirometer

11
ARDS 1. Impaired Oxygenation PaO2/FiO2 ratio
lt 200 (normal gt 450) 2. Bilateral pulmonary
infiltrates on CXR 3. PCW lt 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.

12
Causes

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

13
Levy G, Shabot MM, Hart M, et al Transfusion
associated non-cardiogenic pulmonary edema.
Transfusion 198626 278.
Levy G, Shabot MM, Hart M, et al Transfusion
associated non-cardiogenic pulmonary edema.
Transfusion 198626 278.
14
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

15
Inflammatory Mediators
Cells

• Thromboxane A2
• Prostacyclin
• Leukotrienes
• Platelet-activating factor (PAF)
• Bradykinin
• C3a, C5a
• Tumor necrosis factor
• IL-1, IL-6
• Elastase, Collagenase
• Oxygen free radicals

• Leucocytes
• Macrophages
• Monocytes
• Endothelial cells
• Mast cells
• Bosophils
• Fibroblasts
• Platelets

Nothing New...
Still cant do anything about em!
16
Causes Time of Death After Multiple Trauma
17
New Ventilator Strategies - I
Goal Reduce Alveolar distention
Marcy Marini. Chest 1991100494
18
New Ventilator Strategies

• Permissive hypercapnia

• Pressure controlled ventilation
• Pressure release ventilation
• Low volume pressure-limited ventilation
• Inverse ratio ventilation
• Prone ventilation

19
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

20
Prone Positioning
Stocker et al. Chest 19971111008
21
Extracorporeal CO2 Removal (ECCO2R)
Status Ineffective
Guinard et al. Clin Invest Crit Care
19971111000
22
Other New Ventilator Strategies

• High frequency ventilation (gt60/min)

• High Positive End-Expiratory Pressure (PEEP)
  ventilation

• Extra-corporeal membrane oxygenation (ECMO)

• Extra-Corporeal CO2 Removal (ECCOR)

• Partial Liquid Ventilation

23
Partial Liquid Ventilation
Leach et al. Crit Care Med 1993211270.
24
Partial Liquid Ventilation
Status Unproven
Partial Liquid Vent
Conventional Vent
25
New Pharmacologic Strategies

• Inhaled nitric oxide (NO)

• Surfactant replacement
• Ketoconazole
• Prostaglandin E1
• Non-steroidal anti-inflammatory agents
• High dose steroids (again)

26
Pharmacologic Treatment of ARDS
Kollef Schuster. NEJM 199533227.
27
How the SICU Does It
Patient R.N.

• 31 y/o female

• 2 days S/P laparoscopic GYN procedure
• Found hypotensive, febrile on ward
• CT abdomen - fluid collections air
• OR ð SB perf massive contamination
• SICU postop - hypotensive on vent

28
4/5
29
4/11
30
Surgical ICU Management

• Hemodynamic/Swan-Ganz monitoring

• Volume resuscitation gt 20L (sepsis)
• Triple antibiotics
• Dopamine, neosynepherine
• CT guided abscess drainage
• Repeat laparotomy drainage

31
4/13/
32
Ventilator Management

• A/C volume vent ð Pressure Control vent

• Inverse Ratio ventilation
• Paralysis sedation gt 10 days
• Permissive hypercapnia
• High PEEP (as required) 15 cm H2O
• High FiO2 (as required) 100 7 days
• Tracheostomy

33
4/20
34
ARDS Management Principles
ü
ü
Brandstetter RD. Heart Lung 199726 3-14
35
ARDS Prognosis - Overall
Milberg at al. JAMA 1995273306.
36
The News on ARDS in Summary
The good news is.
The prognosis and survival for ARDS is improving!
The bad news is.
WERE NOT EXACTLY SURE WHY!
37
Hemodynamic Monitoring and Vasoactive Drugs
38
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.
• Cardiogenic
• Hypovolemic
• Septic
• Neurogenic
• Cardiac compressive

39
CONTROL OF CARDIAC OUTPUT

• PRELOAD
• left ventricular end diastolic pressure
• AFTERLOAD
• pressure against which the left ventricle
• must eject blood
• HEART RATE
• CONTRACTILITY
• strength of left ventricular contraction

40
CONTROL OF CARDIAC OUTPUT
41
Pulmonary Artery Catheter
42
Starling Curves
43
Catheter Insertion Waveforms
44
CONTROL OF CARDIAC OUTPUT
45
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

46
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

47
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 )

48
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.

49
Intensive Care Medicine

• Ventilators
• ARDS
• Hemodynamic Monitoring
• Vasoactive Drugs