N401 Mechanical Ventilation

PEEP

positive end expiratory pressure

works to keep alveoli open for as long as possible to improve exchange of O2 and CO2 (oxygenation)

CPAP

continous positive airway pressure

works to keep alveoli open for as long as possible to improve exchange of O2 and CO2 (oxygenation)

EPAP

expiratory positive airway pressure

works to keep alveoli open for as long as possible to improve exchange of O2 and CO2 (oxygenation)

PS

pressure support

works to overcome the work of breathing with a BIPAP/ET tube

PIP

airway pressure or peak inspiratory pressure

highest amount of pressure in your lungs before you exhale

tidal volume

the amount of air that moves in or out of the lungs with each normal, resting breath

oral airways

insert sideways and rotate inside mouth

• only for unconscious patients

• use a bite block

• can cause laryngospasm, gagging, vomiting, and oral trauma

nasal airways

used for nasotracheal suctioning (secretion control)

• not in intubated patients

• changed every 8-12 hours so it doesn’t adhere to your nose

• can cause severe nasal trauma

endotracheal tube

airway maintenance and protection

secretion control (can cause aspiration)

oxygenation and or ventilation

beveled tip location

Beveled tip: stays like 3-5cm above the carina to prevent trauma (cough center of the lungs)

verification for ET tube

• IMMEDIATELY check for bilateral breath sounds and chest movement

• verify with CO2 detector

• CXR: end of tube should be 3-4cm above the carina

• note number on the ET tube at the lips

cuff pressure

20-25 mmHg or 25-30 cm H2O

airway suctioning indications

adventitious breath sounds

sawtooth pattern on the ventilator

coughing

increased peak airway pressures

secretions in the ET tube

decreasing SaO2 or paO2

airway suctioning

PRN only

hyper-oxygenate before and after

15 seconds only

right mainstem intubation

evidenced by breath sounds in right lung with none in left lung

unplanned extubation prevention

ET tube is removed before “ready” d/t patient care (turns) or d/t patient pulling it out

• restraints

• spontaneous awakening trial: continuous sedation with daily “sedation vacation”

• spontaneous breathing trial: assessment of readiness to extubate (most reliable)

pneumonia

acute inflammation of lung parenchyma caused by infectious agent

• HAP: hospital acquired pneumonia

• VAE: ventilator associated event

  • includes VAP

  • clinically occurs after 48 hours of intubation

causes of VAP

• aspiration

• intubation procedure

• biofilm formation

• contaminated secretions

• contaminated respiratory equipment

prevention of VAP

daily oral care with an alcohol-free antiseptic rinse

HOB at 30-35 degrees

Mechanical ventilation indications

hypoxemia: paO2 <50 mmHg and/or hypoventilation: paCO2 > 50 with acidosis

parts of the ventilator orders

• mode

  • how the ventilator addresses ventilator given breaths

  • how the ventilator addresses spontaneous breaths

• FiO2: fraction of inspired oxygen (how much of the air the ventilator is pushing in contains oxygen)

• PEEP: positive end expiratory pressure (keeps alveoli open a the end of expiration to facilitate and improve gas exchange)

• RR: respiratory rate (frequency)

  • the number of breaths the ventilator is going to deliver before spontaneous breaths

volume controlled (VC) breaths

a preset tidal volume is maintained during inspiration - airway pressure reached to achieve that volume is variable (dependent on lung compliance)

• all set rate, FiO2, and PEEP

pressure controlled (PC) breaths

a preset airway pressure is maintained throughout inspiration - tidal volume achieved at that pressure is variable (dependent on lung compliance)

• all set rate, FiO2, and PEEP

spontaneous AC breath

• a full vent breath delivered at preset tidal volume or pressure (with O2)

• PEEP: all (except Peds/Neonate)

ALL BREATHS (SPONTANEOUS OR VENTILATOR) LOOK THE SAME

synchronized intermittent mandatory ventilation (SIMV)

• patient pulls their own tidal volume or pressure (with O2) with support to overcome dead space

• CPAP: all

• pressure support: all

  • small amount of positive pressure delivered during spontaneous breaths (NO vent breaths provided)

  • improves spontaneous tidal volume (good for weaning)

SPONTANEOUS BREATH LOOKS DIFFERENT THAN VENTILATOR BREATH

complications of mechanical ventilation

VAP

• decreased cardiac output

  • positive pressure ventilation causes increased intrathoracic pressure causes decreases venous return (preload)

  • PEEP or CPAP significantly worsen the effect

manage by providing adequate fluids or vasopressors

• trauma

  • volutrauma: increased tidal volume producing over distention of the alveoli

  • barotrauma: increased peak pressures and PEEP stressing the alveolar tissue

  • atelectrauma: repeated opening and closing creating non-physiologic stress

• upper airway trauma

  • nose, lips, tongue, teeth, trachea

• GI disorders

  • stress ulcers: related to length of time on vent (prevent with tube feeding or prophylactic H2 blocker)

  • gastric distention

• overventilation: decreased paCO2 causing respiratory alkalosis

  • use of AC mode

  • rate too high

  • no need for a ventilator

weaning from mechanical ventilation

• physiologic readiness

• hemodynamically stable

• adequate ventilatory drive: > 5-10L/min

• adequate pulmonary mechanics

  • vital capacity > 15ml/kg

  • negative inspiratory pressure (NIP) < 30cm

• spontaneous breathing trial

  • CPAP (5cm) or PS (7cm) used to decreased work of breath and airway collapse

  • increase FiO2 by 0.1