Common means of sedation for patient receiving mechanical ventilation
propofol ("milk of amnesia")
Once inserted, what is important for the initial nurse to establish concerning the ET tube?
Measurement of the tube (on the tube itself) at a specific point on the patient.
Ex: 22 cm at the patient's lip.
If this changes, we know the tube has moved.
Unless medically contraindicated, how should a mechanically ventilated patient be positioned?
Supine, HOB at 30 - 45 degrees (to prevent aspiration)
What other intervention is almost always administered with mechanical ventilation?
OG or NG tube to intermittent suction
Fraction of inspired oxygen delivered to the patient. May be between 21% (normal room air) and 100%.
Positive End-Expiratory Pressure.
The amount of residual pressure in the lungs at the end of expiration that keeps alveoli partially inflated so they are more easily inflated and perfused with the next breath.
~ 5 cm H2O
The degree of negative pressure created by the patient's attempt to breathe that will stimulate the ventilator to either administer a full breath, or assist the patient with positive air pressure.
Controlled Mandatory Ventilation
Ventilator does all the work. Set rate and tidal volume that is delivered with each breath. No accommodation for patient-initiated breaths. Administered to patient who are paralyzed or heavily sedated.
There is a set rate and tidal volume. BUT, the patient is able to initiate an extra breath. The "extra breath" is delivered by the machine, NOT performed by the patient. The delivered breath is a full-tidal volume breath (may be more than the patient needed).
Synchronized Intermittent Mandatory Ventilation
A preset rate and tidal volume are set, but the machine allows the patient to initiate AND perform their own breaths as well. Positive pressure is applied to ASSIST with the breath, but it is the patient doing the WOB. The ventilator synchronizes the automated breaths with the patient's own breaths.
Pressure Support Ventilation
Positive pressure that is applied to the airway ONLY DURING INSPIRATION. The patient initiates and performs that actual breaths, but the machine makes them easier with positive pressure. Think of really smart CPAP. Decreases the work of breathing. Patient has to have their own stable respiratory drive.
Primary nursing concerns with Vents
Regularly auscultate breath sounds and monitor RR for irregularities. Maintain appropriate tube placement and cuff inflation. Prevent skin breakdown. Develop plan for communication (before insertion if possible). Administer sedatives, analgesics, and/or paralytics prn to maintain comfort and promote cooperation with vent. ET tube suctioning. Monitor ABGs.
Extracorporeal Membrane Oxygenation.
Modification of cardiac bypass. Large-bore catheters are inserted, blood is removed, oxygenated, CO2 is removed, and then returned to body.
Complications with positive pressure ventilation
Increased intra-thoracic pressure can cause compression of thoracic vessels.
Hypotension (We need to compensate to avoid shock)
The PRESSURE of the air can cause damage to lungs / alveoli. Patients with decreased pulmonary accommodation (emphysema) are at increased risk. Can lead to pneumothorax.
The VOLUME of the air is more than the lungs can handle and physical damage to the lungs occurs.
Hypo- and Hyperventilation of alveoli
Can lead to abnormal PaO2 and PaCO2 levels --> pH alterations --> acidosis / alkalosis --> etc.
What is the main thing we want to avoid with mechanical ventilation??
Ventilator Associated Pneumonia (VAP). 9 - 27% of all intubated patients.
Signs of VAP
Elevated temp and WBCs. Purulent sputum. Odorous sputum. Crackles or rhonchi on auscultation. Pulmonary infiltrates on X-ray.
Nursing interventions to prevent VAP
HOB elevated to 30 - 45 degrees. Use of an ET-tube with a suction port above the cuff. Proper and regular oral care. Oral suctioning prn. HAND WASHING and proper aseptic/clean technique as indicated.
What medications can be expected to help prevent aspiration?
H2 receptor blockers (Zantac) and proton pump inhibitors (Nexium, Protonix). Decrease gastric acid secretions.
Problems caused by increased thoracic pressure
Decreased BP --> decreased tissue perfusion.
Decreased blood flow back to heart --> INCREASED ICP, decreased myocardial and pulmonary perfusion.
Proper oral care of a ventilated patient
Brush their teeth 2x / day.
Apply moisturizing agent to lips q4h.
What test is performed before paralyzing a patient for Ventilation therapy?
Train-of-Four (TOF) of the ulnar nerve