Approach to Critical Illness Flashcards
Organ systems assessed in Sequential Organ Failure Assessment (SOFA) scoring
6 (six)
Respiration
Coagulation
Liver
Cardiovascular
Central Nervous System
Renal
SOFA scoring diagnostic of SEPSIS
Increase of atleast 2 points in SOFA scoring from baseline, in the setting of suspected or documented infection
qSOFA parameters
RR >/= 22 bpm
Altered mental status
SBP = 100 mmHg
Most commonly used SOI scoring system in North America
THE APACHE II scoring system
What is shock?
Presence of multisystem end-organ hypoperfusion
Clinical indicators of Shock
Reduced MAP
Tachycardia
Tachypnea
Cool skin and extremities
Acute altered mental status
Oliguria
End result of multiorgan hypoperfusion
Tissue hypoxia, often accompanied by lactic acidosis
Mean Arterial Pressure
Cardiac Output x Systemic Vascular Resistance
Components of APACHE II scoring system
Rectal temperature
Mean blood pressure
Heart rate
Respiratory rate
Arterial pH
Oxygenation
Serum Sodium
Serum Potassium
Serum Creatinine
Hematocrit
WBC count
Glasgow Coma Score
Ag
Chronic Health Conditions
Clinical evidence of diminished cardiac output
Narrow Pulse Pressure
Cool extremities with delayed capillary refill
Signs of increased cardiac output
Widened pulse pressure ( ⬇️ diastolic pressure)
Warm extremities with bounding pulses
Rapid capillary refill
In hypotensive patients, with clinical signs of increased cardiac output, reduced BP is due to ___
Decreased Systemic vascular resistance
Better predictor of fluid responsiveness in hypotensive patients with reduced cardiac output
Change in right atrial pressure as a function of spontaneous respiration
Most common cause of High Cardiac Output Shock
Sepsis
Causes of Acute Hypoxemic Respiratory Failure
-Cardiogenic Shock
-Pulmonary Edema
-Septic shock with pneumonia
-ARDS
Causes of Ventilatory Failure
Increased load on the respiratory system
-Acute Metabolic (Lactic) Acidosis
Decreased Lung compliance
-Pulmonary Edema
Inadequate perfusion to respiratory muscles in the setting of shock
Predictor of fluid-responsiveness in spontaneously breathing patient
Inferior vena cava collapse seen on ultrasound
Signs of Respiratory Distress
-Inability to speak full sentences
-Accessory use of respiratory muscles
-Paradoxical abdominal muscle activity
-Extreme tachypnea (>40 bpm)
-Decreasing RR despite increasing drive to breathe
Goals in Mechanical Ventilation (2)
- Initially assume all or the majority of the work of breathing
- Facilitate a state of minimal respiratory muscle work
Decline in MAP seen during Mechanical Ventilation is caused by:
- Impeded venous return from positive-pressure ventilation
- Reduced endogenous catecholamine secretion once the stress associated with respiratory failure abates
- Actions of drugs used to facilitate endotracheal intubation
- Increase in RV afterload from positive-pressure ventilation in patients with Right Heart Dysfunction and Preexisting Pulmonary Hypertension
How to prevent decrease in MAP during intubation?
- IV volume administration
- Vasopressor support pre-intubation
This type of respiratory failure occurs with alveolar flooding and subsequent ventilation-perfusion mismatch and intrapulmonary shunt physiology
Type 1: Acute Hypoxemic Respiratory Failure
Categories of Pulmonary Edema
- Elevated Pulmonary Microvascular Pressures
A. Heart Failure
B. Intravascular Volume Overload - Low pressure Pulmonary Edema
A. Acute Respiratory Distress Syndrome
The pressure-volume relationship of the lung in ARDS in ______
Not linear
Principles in management of ARDS
- Low tidal volume 6mL/kg of IBW and High PEEP
- Prone positioning** improve survival
- Neuromuscular blockade
- Fluid-Conservative management strategy
This type of respiratory failure is a consequence of alveolar hypoventilation resulting from the inability to eliminate CO2 effectively
Type II: Hypercapneic Respiratory Failure
Mechanisms of Type II Respiratory Failure
- Impaired CNS drive to breathe
A. Drug Overdose
B. Brainstem Injury
C. Sleep-disordered breathing
D. Severe hypothyroidism - Impaired strength
A. Impaired neuromuscular transmission
-Myasthenia Gravis
-GBS
-Amyotrophic lateral sclerosis
B. Respiratory Muscle Weakness
-Myopathy
-Electrolyte derangements
-Fatigue - Increased load on the respiratory system
A. Resistive Loads
- Bronchospasms
B. Reduced Lung Compliance
- Alveolar edema
-Atelectasis
-Intrinsic PEEP (Auto-PEEP)
C. Reduced chest wall compliance
-Pneumothorax
-Pleural Effusion
-Abdominal Distention
D. Increased Minute Ventilation
-Pulmonary Embolism
-Increased dead-space fraction
-Sepsis
Treatment of Hypercapnic Respiratory Failure
Non-invasive positive-pressure ventilation with tight-fitting facial or nasal mask with avoidance of endotracheal intubation
This form of respiratory failure results from lung atelectasis
Type III: aka Perioperative Respiratory Failure