Respiratory Therapy and Ventilation Concepts

Practice flashcards covering Winter's Formula, ventilator setting calculations, and non-invasive ventilation (CPAP/BiPAP) equipment and modes.

Winter's Formula

A calculation used in the presence of metabolic acidosis to determine the target $CO_2$ range needed for full compensation, calculated as $(\text{bicarb} \times 1.5) + 8 \text{ with a range of } \nu \text{ plus or minus } 2$.

Metabolic Acidosis

A clinical condition characterized by a low pH (e.g., $7.24$) and a low bicarb where the $CO_2$ decreases in an attempt to bring the pH back up.

Desired $CO_2$ Calculation

A formula to determine the necessary respiratory rate to achieve a target $CO_2$: $\frac{\text{known } CO_2 \times \text{known rate}}{\text{desired } CO_2}$.

V 60

A common hospital ventilator used for non-invasive ventilation that includes features such as disconnect alarms and specialty modes like AVAPS.

CPAP

Continuous Positive Airway Pressure; a single set pressure (e.g., $10 \text{ cm } H_2O$) used for typical obstructive sleep apnea to split the airway open while the patient breathes.

BiPAP

Two levels of pressure (e.g., $12$ over $6$) often including a backup rate, used for patients with a respiratory failure component such as COPD.

Auto-titrating CPAP

A device where a clinician sets a pressure range (e.g., $8 \text{ to } 15 \text{ cm } H_2O$) and the machine assesses breathing/obstruction to adjust the delivered pressure automatically.

AVAPS

Automatic Volume Assured Pressure Support; a specialty pressure-based mode on the V 60 where the machine adjusts pressure to achieve a set tidal volume.

IVAPS

Intelligent Volume Assured Pressure Support; a volume-assured pressure support mode used in specific respiratory therapy machines.

Central Sleep Apnea

A condition where regular CPAP may not work because the patient lacks the central drive to breathe, requiring the machine to provide actual ventilation.

Tidal Volume Calculation

The process of measuring a patient's height to determine the appropriate volume and verifying the $ml/kg$ of tidal volume they are receiving from the ventilator.