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(BQ) Part 2 book “The walls manual of emergency airway management” has contents: Pharmacology and techniques of airway management, pediatric airway management, ems airway management, special clinical circumstances.
Section V Pharmacology and Techniques of Airway Management 20 Rapid Sequence Intubation 21 Sedative Induction Agents 22 Neuromuscular Blocking Agents 23 Anesthesia and Sedation for Awake Intubation Chapter 20 Rapid Sequence Intubation Calvin A Brown III and Ron M Walls INTRODUCTION Definition Rapid sequence intubation (RSI) is the administration, after preoxygenation and patient optimization, of a potent induction agent followed immediately by a rapidly acting neuromuscular blocking agent (NMBA) to induce unconsciousness and motor paralysis for tracheal intubation The technique is predicated on the fact that the patient has not fasted before intubation and, therefore, is at risk for aspiration of gastric contents The preoxygenation phase begins before drug administration and permits a period of apnea to occur safely between the administration of the drugs and intubation of the trachea without the need for positive-pressure ventilation Likewise, preintubation optimization is a step focused on maximizing patient hemodynamics and overall physiology before RSI drugs are given and is designed predominantly to protect against circulatory collapse during or immediately after the intubation In other words, the purpose of RSI is to render the patient unconscious and paralyzed and then to intubate the trachea, with the patient as oxygenated and physiologically optimized as possible, without the use of bag-mask ventilation, which may cause gastric distention and increase the risk of aspiration The Sellick maneuver (posterior pressure on the cricoid cartilage to occlude the esophagus and prevent passive regurgitation) has been shown to impair glottic visualization in some cases, and the evidence supporting its use is dubious, at best As in the fourth edition, we no longer recommend routine use of this maneuver during emergency intubation Indications and Contraindications Indications and Contraindications RSI is the cornerstone of emergency airway management and is the technique of choice when emergency intubation is indicated, and the patient does not have difficult airway features felt to contraindicate the use of an NMBA (see Chapters and 3) When a contraindication to succinylcholine is present, rocuronium should be used as the NMBA (see Chapter 22) Some practitioners eschew the use of succinylcholine and routinely use rocuronium for all intubations; this is a matter of preference, for there are both pros and cons to this approach TECHNIQUE RSI can be thought of as a series of discrete steps, referred to as the seven Ps Although conceptualizing RSI as a series of individual actions is helpful when teaching or planning the technique, most emergency intubations require that several steps, especially leading up to tube placement, occur simultaneously In this latest edition, preintubation optimization has replaced pretreatment as the third “P” in RSI because a critical reappraisal of the available evidence behind pretreatment agents has failed to identify high-quality studies or clear patient benefit, except when these agents are used to optimize the patient’s physiologic state to better tolerate the medications, intubation, and positive-pressure ventilation Otherwise, adding unnecessary drugs contributes to procedural inefficiencies and introduces the potential for adverse drugs reactions and dosing errors The seven Ps of RSI are shown in Box 20-1 Preparation Before initiating the sequence, the patient is thoroughly assessed for difficulty of intubation (see Chapter 2) Fallback plans in the event of failed intubation are established, and the necessary equipment is located The patient is in an area of the emergency department that is organized and equipped for resuscitation Cardiac monitoring, BP monitoring, and pulse oximetry should be used in all cases Continuous waveform capnography provides additional valuable monitoring information, particularly after intubation, and should be used whenever possible The patient should have at least one, and preferably two, secure, well-functioning intravenous (IV) lines Pharmacologic agents are drawn up in properly labeled syringes Vital equipment is tested A video laryngoscope, if available, should be brought to the bedside and tested for image clarity whether or not it is to be used on first attempt If a direct laryngoscope is to be used, the blade of choice is affixed to the laryngoscope handle and clicked into the “on” position to ensure that the light functions and is bright The endotracheal tube (ETT) of the desired size is prepared, and the cuff is tested for leaks If difficult intubation is anticipated, a tube 0.5 mm or less in internal diameter (ID) should also be prepared Selection and preparation of the tube, as well as the use of the intubating stylet and bougie, are discussed in Chapter 13 Throughout this preparatory phase, the patient is receiving preoxygenation and optimization measures, if appropriate, as described in the next two sections Preoxygenation Preoxygenation is essential to the “no bagging” principle of RSI Preoxygenation is the establishment of an oxygen reservoir within the lungs, blood, and body tissue to permit several minutes of apnea to occur without arterial oxygen desaturation The principal reservoir is the functional residual capacity in the lungs, which is approximately 30 mL per kg Administration of 100% oxygen for minutes replaces this predominantly nitrogenous mixture of room air with oxygen, allowing several minutes of apnea time before hemoglobin saturation decreases to 90% for minutes, whereas an obese adult will desaturate to 90% in