Daniel E. Becker, Morton B. Rosenberg, and James C. Phero
Context
- Offices and outpatient dental facilities must be properly equipped with devices for airway management, oxygenation, and ventilation. Optimizing patient safety using crisis resource management (CRM) involves the entire dental office team being familiar with airway rescue equipment.
- The immediate availability of this equipment is especially important during the administration of sedation and anesthesia as well as the treatment of medical urgencies/emergencies.
- Basic airway rescue algorithms all follow a step-wise approach beginning with attempts at opening the airway via head tilt, chin lift, and jaw extension, proceeding to positive pressure ventilation with a bag-valve-mask system and, if needed, the insertion of an oropharyngeal or nasopharyngeal airway.
Oxygen Cylinders and Regulators
- Every dental office must be equipped with an oxygen source.
- Large H-cylinders and portable E-cylinders are most commonly used in the dental environment.
- A portable E-cylinder of oxygen should always be available and at least one additional backup cylinder should be kept in reserve.
- E-cylinders provide the most appropriate balance of having sufficient oxygen for an emergency, yet are small enough to be portable. A full E-cylinder holds over 600 liters of oxygen and will indicate a pressure of approximately 2200 psi. They should be replaced when their content falls to 500 psi.
- Estimates of time remaining in oxygen cylinders can be approximated using the following formula where the conversion factor (F) = ∼0.3 for E-cylinders and ∼3.0 for large H-cylinders that supply central plumbing: (psi × F) / L/min = time remaining in minutes.1
Devices for Supplemental Oxygenation
- Nasal cannulas, nasal hoods, various mask designs, and certain resuscitation bags may be used to provide supplemental oxygen for the spontaneously breathing patient.
- Nasal cannula: ideal for administering supplemental oxygen to sedated patients as well as those experiencing a medical complication.
- Face masks: provide higher oxygen concentrations but such concentrations may not be required depending upon the situation. For routine supplementation during minimal or moderate procedural sedation, 2 L/min or 28% oxygen is conventional.
- Oxygen masks: traditionally, prehospital emergency responders set the mask flow at 10 L/min as standard practice. A minimum of 6 L/min should be delivered to the mask before placing it on the patient.
- Facemasks with oxygen reservoir bags provide higher concentrations (60–80%) than simple face masks, but the reservoir must be inflated before placing the mask on the patient.1
- Two rules should always be followed: (a) oxygen flow should be established to the mask before placing it on the patient and (b) if a reservoir bag is present it should be filled prior to placement.
- Dated concerns regarding oxygen supplementation depressing hypoxemic drive in patients with chronic obstructive pulmonary disease (COPD) are not valid during emergency interventions.
Devices for Positive Pressure Supplemental and Controlled Ventilation
- Every dental office must have the ability to deliver oxygen with positive pressure which could be accomplished with either oxygen-powered resuscitators (e.g., Robertshaw or Elder Demand Valves) or with resuscitation bag-valve-mask (BVM) devices.
- The goal of positive pressure ventilation is to assure that an adequate volume of oxygen reaches the lungs.
- Although oxygen-powered resuscitators appear simple to use, their delivered inspiratory pressures cannot be modified easily, and the loss of the feel of chest compliance may easily lead to gastric insufflation and also produce lung barotrauma.
Basic Airway Adjuncts
- Oropharyngeal airways are adjuncts that improve airway patency by keeping the mouth open and overcome soft tissue obstruction caused by the base of the tongue sagging against the posterior pharyngeal wall. They are inserted in unconscious, nonresponsive patients who cannot be ventilated adequately using simple head-tilt and chin-lift alone.
- Oropharyngeal airways must be inserted cautiously in order to avoid pushing the tongue caudally and worsening the obstruction.
- Nasopharyngeal airways are softened tubes available in various sizes based on their diameter. They are inserted through a nostril and maintain patency between the tongue and posterior pharyngeal wall.
- Nasopharyngeal airways should not be used without proper training and are contraindicated for patients who are anticoagulated, have bleeding diatheses, or have nasal deformities or a history of nosebleeds.
- During any airway emergency, a Yankauer suction device (“tonsil suction”) should be available to clear the posterior pharynx of secretions and debris.
References