Mechanical Ventilation and ARDS

comfort, breathing, gas, supportive

Goals of Mechanical Ventilation

-Maximize patient _______

-Decrease work of __________

-Provide adequate ___ exchange: oxygenation and ventilation

-Minimize adverse effects

-Remember: the vent is a _________ therapy

oxygenate, ventilate

Lingo

- “My patient is difficult to ________”

• Low PaO2, spO2

• Refractory hypoxemia

- “My patient is difficult to ________”

• High pCO2, respiratory acidosis

• Refractory hypercarbnia

CO2, O2

Tidal volume and respiratory rate are related to ___, while PEEP and FiO2 are related to __

high, decrease, RV

PEEP and Hemodynamics

-____ PEEP → hemodynamic compromise

-Increased intrathoracic pressure → _______ venous return

-Increased pulmonary vascular resistance → increased __ afterload

increasing, tidal volume

Treating Hypercapnia

-You can treat hypercapnia by _________ the patient’s respiratory rate or ____ ______

Minute Ventilation

amount of air breathed per minute

MV = RR x TV

Air Trapping

A condition in which air is not fully exhaled from the lungs, often leading to increased lung volume and difficulty in breathing. It commonly occurs in obstructive lung diseases.

increasing, not, PEEP

Improving Ventilation

-_________ the rate is ___ always the answer

-Check for intrinsic _____

-Sometimes you have to decrease their respiration rate to help them

ventilator, patient

Breath Types

-With controlled breaths, the _________ does all the work

-With assisted breaths, the patient starts the breath, but the ventilator takes over the work

-With supported breaths, the _______ is able to do some or most of the work, and the ventilator assists to finish the work

VC

volume controlled breath

PC

pressure controlled breath

AC/VC+

the most common vent mode used in practice

ventilator, volume, lowest, pressure

AC/VC or AC/VC+ Overview

-Assist control → _________ is doing the work

-Volume control → we set the tidal _______

-Volume control plus → we set the tidal volume + the vent adjusts each breath to give the set volume at the _________ pressure

-Set the volume, need to monitor the _______

peak, inflate, plateau, alveoli, pause

Volume Control: Monitor Pressures

-______ pressure → dynamic compliance

• Overcome resistive and elastic forces needed to _____ the lung

• Displayed on the ventilator

-_______ pressure → static compliance

• Distending pressures of small airways and ______

• Measured at the end of inspiration

• Requires and inspiratory ______ maneuver

Barotrauma

a condition caused by excessive pressure in the lungs, leading to damage, often occurring with mechanical ventilation

Volutrauma

a type of lung injury caused by excessive volume during mechanical ventilation, resulting in overdistension and damage to alveoli

ventilator, pressure, volumes, comfortable

AC/PC Overview

-Assist control → _________ is doing the work

-_______ control → we set the pressure

-Variable _______, monitor them

-Pressure modes are generally more _________ for patients

CPAP, patient, extubation

Spontaneous Modes

-Pressure support/____

• Set a given level of support

• ________ is breathing on their own

• Used with weaning trials to see if the patient is ready for ____________

30

Plateau pressure needs to be < __

paralyzed, supported, OR

Synchronized Intermittent Mandatory Ventilation

-If a patient is _________, this mode looks just like AC modes of ventilation

-If a patient is sedated/awake and wants to take extra breaths → they are __________ breaths

-Used frequently in __/anesthesia

ARDS

life-threatening respiratory failure due to widespread lung inflammation

-non-cardiogenic pulmonary edema and severe hypoxemia

Berlin Criteria

A set of criteria used to diagnose ARDS:

1. Acute onset within 1 week of known insult

2. Bilateral opacities on chest imaging

3. Not explained by cardiac failure or fluid overload

4. PaO2/FiO2 < 300 mmHg with PEEP > 5 cm H2O

direct, pneumonia, injury, sepsis

Etiologies of ARDS

-_______ Lung Injury:

• _________ (bacterial/viral, including COVID)

• Aspiration

• Inhalation ______

• Near-drowning

-Indirect Lung Injury:

• ______ (most common)

• Trauma

• Pancreatitis

• Drug overdose

P/F Ratio

the ratio of arterial oxygen partial pressure (PaO2) to fractional inspired oxygen (FiO2), used to assess the severity of hypoxemia in patients with respiratory failure

Mild, 100, <, edema

ARDS Diagnosis

-PaO2/FiO2 < 300

• p/f 200-300 → ____

• p/f ___-200 → moderate

• p/f _ 100 → severe

-Noncardiogenic pulmonary ______

-ARDSnet Trial

• Multi-center RCT

• Compared high vs low TV in ARDS

high, low, healthcare, negative

COVID-19 Ventilator Management Pearls

-Generally follow ARDSnet strategy of ___ PEEP and ___ tidal volume

-Prone positioning

-Minimize _________ worker exposure: intubation measures, do not disconnect circuit

-No intubation/BiPAP/HFNC unless in ______ airflow room

BiPAP, edema, CPAP, OHS

Non-Invasive Positive Pressure Ventilation (NIPPV)

-CPAP vs BiPAP vs AVAPs

-Acute respiratory failure → _____ or AVAPS

• Acute hypercarbia

• Pulmonary ____

-Chronic NIPPV OSA, ___, chronic hypercapnia, COPD, etc.

• CPAP = OSA

• BiPAP or AVAPS = complex or central sleep apnea, OHS, chronic hypercarbia, COPD

ECMO

a life-supporting technique used in severe cases of respiratory or cardiac failure, providing temporary support to the heart and lungs by oxygenating blood outside the body

-VV = veno-venous, used for isolated respiratory failure

-VA = veno-arterial, combined cardiorespiratory failure

Open Pneumothorax

aka sucking chest wound

-from trauma

-requires a hole in the chest the size of a nickel

-air follows the path of least resistance

acidotic

Never intubate a DKA or any severely metabolically ________ patient because a patient can compensate on their own better than we can with a ventilator

chest tube

How do you treat an open pneumothorax in the hospital?

-In the field, it’s treated with a three sided occlusive dressing

Pseudomediastinum

air in the mediastinal space, which tracks along the mediastinal structures

-can happen spontaneously, usually under barotrauma

-self-limited

-can develop tension pneumomediastinum

Subcutaneous Emphysema

air in the subcutaneous space, usually following procedures or surgeries

-sudden painless soft tissue swelling, with a predilection for the upper chest, neck, and face

-crepitus on PE

-Tx: usually self-limited, fix underlying cause

massive, sub-massive

Defining Pulmonary Embolism

-_______: hemodynamic instability

-___-______: evidence of right-ventricular strain

-Has nothing to do with the size or location of the clot burden