Acute Respiratory Distress Flashcards
General Considerations:
Can be immediately life threatening and must be relieved promptly to avoid asphyxia.
Causes of:
* Trauma to the larynx
* Foreign body aspiration
* Laryngospasm
* Laryngeal edema from thermal injury or angioedema
* Infections
* Acute allergic laryngitis
Foreign body aspiration occurs much less frequently in adults than children
Angioedema more prevelant in adults.
Wider familiarity with Heimlich maneuver has reduced death
Acute Respiratory Distress: Severe Airway Obstruction
Physical Findings:
Unless the patient has progressed to apnea unwitnessed, high-grade upper airway obstruction is usually obvious.
* Pronounced stridorous respirations
* Retractions of the supraclavicular/suprasternal areas of the chest indicate significant obstruction
* Patients with complete airway obstruction may not be able to breathe or speak.
* Patients may have a visible swelling or mass in the neck
* The tongue may be swollen, as may other structures in the month.
Acute Respiratory Obstruction
Lab/Imaging:
Laryngoscopy may reveal a foreign body, tumor, or other obstruction in the larynx or trachea.
CXR, if obtained, may reveal radiopaque obstructions.
Acute Respiratory Obstruction
Treatment:
Immediate first steps:
Obstruction liquids and particulate matter can be removed with rigid suction device with blunt tip (Yankauer)
Foreign bodies such as meat may be removed by the Heimlich maneuver for kids.
Is most often due to soft tissue swelling secondary to infection or angioedema.
* Therapy should be directed to reduce the edema
* Epinephrine topically, by inhalation, or parentally, is the most effective medication for angioedema.
Direct laryngoscopy coupled with the use of forceps is the best method of removing obstructing foreign bodies.
A physician skilled in difficult airway management should care for these patients.
If less invasive methods fail, immediate cricothyrotomy or tracheostomy is required.
Acute Respiratory Obstruction
Disposition:
Patient with easy, uncomplicated removal of an obstructing foreign body may be sent home following a period of observation with instructions.
* Eat more slowly
* Chew more thoroughly.
* Swallow more carefully.
Patients who have lost consciousness but otherwise appear well should be examined and observed.
* Hospitalized only if symptoms develop or persist.
Some patients will have aspirated some material into the lungs. Hospitalization is appropriate if significant aspiration is suspected.
Acute Respiratory Obstruction
Mechanical Ventilation:
Intubation, with subsequent mechanical ventilation, is a common life-saving intervention in emergency situations.
Indications- It is indicated for acute respiratory failure, which is defined as insufficient oxygenation, insufficient ventilation, or both.
Some common acute disorders for which mechanical ventilation may be required are:
* Alveolar filling processes (due to pneumonia, drowning, or CHF).
* Pulmonary vascular disease or injury
* Diseases causing airways obstruction: (due to asthma exacerbation, foreign body, or anaphylaxis).
* Hypoventilation due to brain injury, medication overuse, or chest wall injuries.
* Increased ventilator demand due to sepsis, DKA, anaphylaxis, or massive hemorrhage.
Acute Respiratory Obstruction
Airway Obstruction: Ventilation
To protect the airway.
To improve pulmonary gas exchange
To relieve respiratory distress
To assist with airway and lung healing.
To permit appropriate sedation and neuromuscular blockade.
Mechanical ventilation should be considered early in the course of illness and should not be delayed until the need becomes emergent.
Goals of Mechanical Ventilation
Modes of Mechanical Ventilation: 1of 2
This is a mode of ventilation that can do all the breathing for the patient.
Ventilator settings that you need to set are the following
* RR: Normal setting between 12-16 breaths per minute.
* Tidal Volume: Normal setting between 400-500 ml per breath.
* PEEP: Normal setting 5-10 cm H2O.
* FIO2: If it is not attached to any oxygen supply then you will only be delivering room air (which is 21% oxygen), if you are attached to oxygen then you can adjust anywhere from 21% up to 100% oxygen. Adjust based on pulse ox to obtain a pulse ox < 94%.
Volume Control Ventilation (VC):
Modes of Mechanical Ventilation: 1of 2
This is a mode of ventilation that is only set if the patient is breathing on their own, but need extra support, or you do not have enough sedation to totally sedate them.
Ventilator settings you need to set are the following:
* FIO2: Same as above
* PEEP: Normal settings are between 5-10 cm H2O.
* Pressure support (PS): This is the amount of extra pressure the ventilator delivers on inspiration when the patient triggers a breath.
* Normal setting is between 10-20 cm H2O
You will adjust the amount of PS in order to deliver a tidal volume of 400-500 ml per breath
You will still need to give some amount of sedation while on this setting in order for patient to tolerate an endotracheal tube being in place, but does not require a lot to keep them fully out like it would while on VC ventilation.
Continuous Positive Airway Pressure (CPAP): Airway Obstruction
Monitoring Oxygenation and Ventilation:
You can monitor Oxygenation through a pulse oximeter with the goal of keeping the Oxygen saturation above 94%.
* If your oxygen saturation is above 96% then you can titrate the FIO2 down to keep the saturation between 94-96%. This will allow you to conserve oxygen in your tank and avoid hyperoxia in your patient.
You can monitor Ventilation through an end-tidal CO2 monitor with the goal of keeping the CO2 between 35-45.
You can also draw an arterial blood gas if you have that ability with the goal of PaO2 to be 75-100 mmHg and PaCO2 between 35-45 mmHg.
If you have access to arterial blood gas monitoring your goal is also to keep the blood pH between 7.35 and 7.45.
Acute Respiratory Obstruction
Management of Oxygen Desaturation: Ventilation
Confirm ET tube is in trachea using end-tidal CO2.
If desaturation is severe switch immediately to manual bag ventilation with high flow oxygen and PEEP valve.
Exclude equipment malfunction, loss of O2 supply, circuit disconnection.
Suction the airway (consider simultaneous bag ventilation) to verify patency and clear mucous plugs.
Consider increasing sedation or pharmacological paralysis if ventilator dyssynchrony is present.
Consider pneumothorax/hemothorax.
* Review peak pressure trend if using volume ventilation.
* Review ventilation trend if using pressure control ventilation. VT will decrease if significant pneumothorax develops and ΔP is not changed.
* Evaluate existing chest tubes for proper function.
* Needle decompress the chest and place a chest tube if there is suspicion of pneumothorax and concurrent hemodynamic compromise.
Acute Respiratory Obstruction
Ongoing Management: Ventilation
Always be evaluating for the patient oxygen desaturation.
Frequently checking your oxygen tank pressure so you will know if you are going to run out of oxygen.
Mouth Care:
* Regular mouth care decreases the ventilator associated pneumonia risk.
* Chlorhexidine is the preferred agent for mouth care.
* Recommended frequency is to brush the mouth out with Chlorhexidine every 4 hours, workload permitting
Acute Respiratory Obstruction
