- -A major oxygenation adjunct treatment modality
- –AN IMPORTANT GOAL OF PEEP IS TO AVOID INCREASING FiO2WHICH CAN LEAD TO OXYGEN TOXICITY
Normal physiological PEEP in the average adult is what?
» Levels above 10-12 cm H2O are generally considered high
Positive End Expiratory Pressure Monitoring Guidelines
If a significant drop in BP occurs, PEEP may need to be reduced or vasoactive drugs may be indicated
How do you prevent atelectasis?
- • Ensuring adequate Tidal Volumes
- • Ensuring adequate and appropriate ventilator settings
- – Dependent on every single patient
- • Age
- • Weight
- • Diagnosis
What is Ventilation?
The process by which gases are moved into and out of the lungs
What is Perfusion?
The process of blood moving through the pulmonary capillary system to the alveoli for the purpose of gas exchange
What is Anatomical dead space?
- The entire area from nose to terminal bronchioles where gas flows, but is not exchanged
- Calculated as 2 ml/kg
What is Physiological dead space?
The sum of the anatomical dead space plus the volume of any nonfunctional alveoli
What is Tidal volume?
- The volume of air inspired in a single, resting breath
- • Calculation for TV when placing a patient on a ventilator is 7-10 ml/kg
What is Oxygen Toxicity?
O2 greater than 50% for > 12 hours can destroy type 2 alveolar cells and they don’t make surfactant, thereby creating atelectasis
What are the Factors that increase the amount of energy
- needed for ventilation include?
- – Loss of pulmonary surfactant
- – Increase in airway resistance
- – Decrease in pulmonary compliance
- Acute Respiratory Distress Syndrome
- – Acute lung inflammation
- – Diffuse alveolar-capillary injury
- • Resulting in
- –Refractory Hypoxemia
- – Severe pulmonary edema
- – A decrease in pulmonary compliance
- • The cause of ARDS is not well known
What is Shunting as it relates to Acute Respiratory Distress Syndrome?
- • Blood goes from the RV to the pulmonary vasculature and returns to the LV and never comes in contact with an aerated alveoli
- • Gas exchange can not take place
- • There is a separation of alveoli from blood supply
What causes ARDS?
- – Direct physical or toxic injury to the lungs
- – Indirect, blood-born injury to the lungs
- • Trauma
- • Gastric aspiration
- • Bypass surgery
- • Multiple blood transfusions
- • Infections
- • Sepsis
- • Oxygen toxicity
- • Toxic inhalation
- • Drug overdose
- • Pneumonia
- – High concentration of oxygen
- – Ventilatory support
- – Fluid replacement to maintain cardiac out and perfusion
- – PEEP (Positive End Expiratory Pressure)
- – Adequate Tidal Volume
- – Pressure control ventilation vs. Volume control
- – Drug therapy to support mechanical ventilation
- – Pain management
- – Sedatives
- – Paralytics if needed
What are Pleural effusions?
An abnormal accumulation of fluid between the layers of the membrane that lines the lungs and chest cavity
What are the indications for Surgical Cricothyrotomy?
- • Absolute need for definitive airway, AND
- – unable to perform ETT due to structural or anatomical reasons, AND
- – risk of not securing airway is > than surgical airway risk
- • Absolute need for definitive airway AND
- – unable to clear an upper airway obstruction, AND
- – multiple unsuccessful attempts at ETT, AND
- – other methods of ventilation
Contraindications for Surgical Cricothyrotomy
- • No real demonstrated indication
- • Risks > Benefits
- • Age < 8 years (some say 10, some say 12)
- • Evidence of fractured larynx or cricoid cartilage
- • Evidence of tracheal transection