Respiratory

Rapid Review

• Background
  • Needle cricothyroidotomy involves the insertion of a needle (or small cannula) percutaneously through the cricothyroid membrane to allow for translaryngeal jet ventilation.
  • Preferred over surgical cricothyroidotomy in pediatric patients (< 12 years)
• Indications
  • Inadequate oxygenation/ventilation with an inability to secure airway through other noninvasive strategies
• Contraindications
  • No absolute contraindications
  • Relative contraindications include inability to identify landmarks, major trauma to trachea, or overlying infection/tumor.
• Complications
  • Posterior tracheal perforation, hemorrhage, infection

Pearls

• Needle cricothyrotomy can provide adequate oxygenation, but not adequate ventilation. Avoid using for greater than 45 minutes.
  
  
• If a commercially available kit is not available, you can use a 12-14 gauge angiocatheter connected to 3-mL syringe with the plunger removed. This will allow you to connect a 6.5 mm endotracheal tube and ventilate via BVM

Deep Dive

• How To Do a Percutaneous Cricothyrotomy (Merck Manual)

Rapid Review

• Background
  • Procedure that involves placing a tube through an incision in the cricothyroid membrane to establish a patent airway, typically during life threatening situations.
• Indications
  • Necessary when airway cannot be secured using nonsurgical methods (ex. Intubation, supraglottic); typically in the presence of severe facial trauma, swelling, or distorted anatomy. 
• Contraindications
  • Patients under the age of 12. No absolute contraindications for adults.
• Complications
  • Bleeding, thyroid injury, esophageal/mediastinal perforation, incorrect placement.

Pearls

• The “Scalpel-Finger-Bougie” technique has the benefit of speed and simplicity, as it does not require any specialized equipment
  
  
• Identifying and marking cricothyroid landmarks with a pen prior to the initial incision has been shown to be unreliable for accurate placement, though it does have the benefit of mentally preparing the clinician and team for the possibility of a surgical airway option if intubation fails.

Deep Dive

• The Sphincter Series: Emergent Cricothyrotomy (emDOCs)

Rapid Review

• Background
  • Continuous positive airway pressure (CPAP) is a noninvasive ventilatory modality that can deliver mechanically assisted breaths without the need for intubation/surgical airway. 
• Indications
  • Asthma, COPD, CHF (treatment of associated pulmonary edema), pneumonia.
• Contraindications
  • Respiratory arrest, uncooperative patients, risk of aspiration, burns/facial trauma.
• Complications
  • Decreased cardiac output, gastric distention, barotrauma

Pearls

• For anxious patients with difficulty tolerating CPAP, consider low dose sedation (dexmetatomidine, ketamine, midazolam, fentanyl, etc.)
  
  
• Be ready to move forward with definitive airway management if needed, particularly within the first hour of CPAP initiation. 

Deep Dive

• Non-invasive Ventilation (WikEM)

Rapid Review

• Background
  • Placement of an endotracheal tube using direct visualization for establishment of definitive airway.
• Indications
  • Failure to ventilate/oxygenate; inability to protect airway. May be placed in anticipation for future clinical courses (impending airway compromise, need for transport, etc.)
• Contraindications
  • No absolute contraindications. However, benefits/risks of intubation should be considered in parallel with other airway strategies (supraglottic airways, surgical airways, NIPPV)
• Complications
  • prolonged hypoxia, right main stem placement, esophageal placement.

Pearls

• Resuscitate before you intubate! This includes preoxygenation, fluid boluses,and vasopressors. The goal is to intubate with a SBP >90 and a SpO2 of >94%
  
  
• Endotracheal tubes often get stuck on the arytenoid cartilages during insertion. This can be resolved by withdrawing the tube and inserting again while rotating the tube one-quarter counter-clockwise. 

Deep Dive

• How To Intubate the Critically Ill Like a Boss (REBEL EM)

Rapid Review

• Background
  • Form of indirect laryngoscopy utilizing a rigid transoral video device, most commonly the Airtraq, C-MAC, or Glidescope. 
  • Blade shapes for video laryngoscopy are either standard-geometry blades (SGVL) or hyperangulated blades (HAVL), both requiring different techniques.
• Indications
  • Any patient meeting criteria for endotracheal intubation.
  • Generally preferred over direct laryngoscopy in patients with difficult anatomy.
• Contraindications
  • No absolute contraindications
  • Relative contraindications include need for foreign body removal, blood/emesis in airway.
• Complications
  • Camera contamination w/ blood or emesis in airway
  • Screen failure (hyperangulated blades will not allow for direct view if video malfunctions)

Pearls

• When using a hyperangulated blade, the goal is to achieve a “sub-optimal” view of the vocal cords prior to insertion. Getting too close and achieving full visualization means displacing the eppiglottis, which whill obstruct your intubation attempt.
  
  
• Using a Bougie can be a great way to maximize first pass success, though users may find it difficult to navigate it around airway structures while using a hyperangulated blade.

Deep Dive

• Video Laryngoscopy in the ED: A Review of Devices, Techniques, Evidence (emDocs)

Rapid Review

• Background
  • Mechanical ventilation involves the utilization of a ventilator to apply positive pressure breaths to patients in respiratory failure. 
  • Ventilatory Modes include assist control (AC), synchronized intermittent mechanical ventilation (SIMV), pressure support ventilation (PSV), or volume assist control (VAC)
  • Additional parameters to be set include respiratory rate, PEEP, tidal volume, and FiO2 concentration.
• Indications
  • Respiratory failure, need for airway protection, controlled hyperventilation (ex. head injury)
• Contraindications
  • No absolute contraindications
• Complications
  • “DOPE” (dislodgement, obstruction, pneumothorax, equipment failure)

Pearls

• Tidal volume settings should be set to “ideal” body weight, instead of actual body weight, to avoid hypo/hyperinflation.
  
  
• A good starting point for mechanical ventilation after intubation is Volume Control (6-8mL/kg ideal body weight, RR 16-22, FiO2 100%, and PEEP 5). The settings can be adjusted based on ABG’s and clinical response. 

Deep Dive

• Taking Ownership of the Ventilator – How to Manage and Troubleshoot (emDocs)

Rapid Review

• Background
  • Nasopharyngeal Airway (NPA) is a soft rubber/plastic airway adjunct passed through the nose and into the posterior pharynx,  assisting with oxygenation and ventilation.
  • Similar function to the oropharyngeal airway (OPA), but does not cause a gag reflex.
• Indications
  • Ideal for patients in need of oxygenation/ventilation who are awake or semiconscious w/ intact gag reflex.
• Contraindications
  • Signs of basilar skull fractures or trauma to the midface/nasopharynx
• Complications
  • Few complications. Most often damage to nasal mucosa. 
  • NPA’s that are too long for the patient may extend into the esophageal route and cause gastric distension. 
  • Few reported cases of NPA placement through basilar skull fractures into the brain.

Pearls

• The “sniffing position” is the most ideal position for facilitation of NPA insertion, though this should be avoided in those with suspected cervical spine injury.
  
  
• NPA insertion should be attempted in the right nare initially because, on average, the right nare is larger than the left. 

Deep Dive

• Nasopharyngeal Airway (PubMed)

Rapid Review

• Background
  • Airway adjunct used to open the oropharynx and prevent the tongue from blocking the epiglottitis; thus improving BVM ventilation
• Indications
  • Unresponsive patients w/o a gag reflex
• Contraindications
  • Conscious patients or those with intact gag reflex
• Complications
  • May induce vomiting, increasing the risk of aspiration. May also worsen airway obstruction if inappropriately sized.

Pearls

• Using a correctly sized OPA is crucial. If it is too large, it may cause a laryngospasm. If it is too small, it may cause an airway obstruction. 
  
  
• For patients expected to regain consciousness soon with medical therapy (i.e. opiate overdose), monitor closely and be prepared to remove the OPA promptly to avoid aspiration.

Deep Dive

• Oropharyngeal Airway (PubMed)

Rapid Review

• Background
  • Also known as “extraglottic airways”. These devices are inserted through the oropharynx to provide temporary airway ventilatory management, without passing the vocal cords. Common brands include the laryngeal mask airway (LMA), King Airway, and I-Gel.
• Indications
  • Commonly used as a rescue device after failed intubation attempts, but may also be useful as a conduit for intubation or first-line for prehospital cardiac arrest. 
• Contraindications
  • Gag reflex, spontaneous respirations, facial trauma
• Complications
  • Ineffective placement, aspiration of gastric contents, pharyngeal edema

Pearls

• I-Gel airways have the advantage of not requiring additional inflation once inserted.
  
  
• Although supraglottic airway devices offer some barrier from gastric contents, as well as ports for gastric decompression tubes, it cannot definitively protect the airway from aspiration like an endotracheal tube can.

Deep Dive

• Supraglottic Airway Review (emDOCs)