ADVANCES IN AIRWAY PHARMACOLOGY: Emerging Trends and Evolving Controversy

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Excellence in airway management has become an integral aspect of emergency medicine. Proficiency in managing the airway demands thorough understanding of the relevant anatomy, various laryngoscopic and intubation techniques, and an extensive working knowledge of airway pharmacology. The use of pharmacologic agents for manipulation and control of a patient's airway dates back to the beginnings of medical anesthesia. Since 1842, the year Crawford Long documented the first use of ether to produce surgical anesthesia, the spectrum of anesthetic and airway pharmacology has broadened immensely. Today there are myriad drug classifications and individual agents that possess specific properties, indications, contraindications, cautions, and concern. For the purposes of emergency department (ED) airway management, the physician should be well versed in the use of specific drugs and medications that allow for rapid, safe, and humane control of the airway.

As emergency medicine has evolved as a specialty, so has the approach to managing the airway. With the use of rapid sequence intubation (RSI), emergent airway management has advanced greatly. Consisting of pretreatment, induction, and paralytic phases, the RSI procedure encompasses the use of many types of drugs. The individual agents used are quite variable in onset, effect, and cardiovascular stability. Thus, many issues have emerged regarding the safe and efficacious use of these drugs, both old and new. Subsequently, many ongoing clinical investigations are exploring the properties of various sympathomimetics, sedatives, analgesics, hypnotics, and muscle relaxants, and their uses in airway management. Exciting new drugs, new ways to use the old familiar agents, and new ideas to maximize pharmacokinetic principles—such as synergy, priming, and timing—have arisen in both recent literature and clinical use. Knowledge of emerging trends, as well as the controversial issues regarding indications and contraindications for preindoctrinated airway pharmacology, will significantly broaden the emergency physician's armamentarium for precision airway management.

Section snippets

RAPID SEQUENCE INTUBATION

RSI has become the emergency physician's cornerstone for emergent airway management.96 Its use in the ED has been shown to be a safe and effective approach to managing the airway of critically ill patients.21, 97, 98 The procedure consists of several distinct phases that prepare and manage both the patient's airway and the physiologic responses to laryngoscopy and intubation (Fig. 1). Although RSI technique follows a predetermined sequence, there are often many pharmacologic options within each

PRETREATMENT

Patients requiring emergency airway control are most often critically ill or injured. Emergent management of the airway requires the use of drugs to produce rapidly sufficient anesthesia for laryngoscopy and endotracheal intubation, both of which are considered noxious stimuli. The physician securing the airway must consider the physiologic consequences of this manipulation and proceed accordingly. Laryngoscopy and tracheal intubation are known to increase sympathetic activity,37, 42, 58, 104

INDUCTION

The induction phase of RSI is used to produce anesthesia and unconsciousness. There are many types of drugs capable of achieving these goals, and all are generally classified as intravenous anesthetics. Intravenous induction of anesthesia was first introduced in 1934; John Lundy used thiopental as the first injectable induction agent. Today, numerous pharmacologic classes of drugs are used for induction purposes. To be useful in emergency airway management, each agent should facilitate

PARALYSIS

In the paralysis phase of RSI, neuromuscular blocking agents are employed to facilitate rapid and efficacious endotracheal intubation. A neuromuscular blocker, also known as a muscle relaxant, is a drug that interrupts transmission of nerve impulses at the neuromuscular junction. Because all ED patients empirically are classified as having a “full stomach,” they are considered at risk for aspiration of gastric contents; thus, in RSI the time between induction of anesthesia and actual placement

AWAKE/TOPICAL INTUBATION

An awake intubation is performed on the spontaneously breathing, conscious, or semiconscious patient. This procedure is indicated when endotracheal intubation under the usual RSI conditions of unconsciousness and apnea may prove difficult or dangerous for the patient. Because the aim of this procedure is to preserve the patient's ability to maintain his or her own airway during laryngoscopy, induction and paralytic agents are not employed. Because tracheal manipulation and intubation are

SUMMARY

The practice of emergency medicine is a constant onslaught of decision making and challenges and the issues of airway management are no exception. Obtaining proper airway control requires thoughtful organization and planning, and necessitates a thorough working knowledge of the drugs or medications employed. Because there are so many agents available, expertise in airway pharmacology has become essential. The emergency physician who is well versed in the uses, and the physiologic effects,

References (107)

  • K.E. McGoldrick

    The open globe: Is an alternative to succinylcholine necessary?

    J Clin Anesth

    (1993)
  • C.D. Miller et al.

    IV lignocaine fails to attenuate the cardiovascular response to laryngoscopy and tracheal intubation

    Br J Anaesth

    (1990)
  • M.L. Mingus et al.

    Propofol permits tracheal intubation but does not affect postoperative myalgias

    J Clin Anesth

    (1996)
  • M. Naguib et al.

    Comparison of suxamethonium and different combinations of rocuronium and mivacurium for rapid tracheal intubation in children

    Br J Anaesth

    (1997)
  • D. Pathak et al.

    Effects of alfentanil and lidocaine on the hemodynamic responses to laryngoscopy and tracheal intubation

    J Clin Anesth

    (1990)
  • E. Simhi et al.

    Intubation in children after 0.3 mg/kg of mivacurium

    J Clin Anesth

    (1997)
  • H. Singh et al.

    Comparative effects of lidocaine, esmolol, and nitroglycerin in modifying the hemodynamic response to laryngoscopy and intubation

    J Clin Anesth

    (1995)
  • I. Smith et al.

    Comparison of intubating conditions after rocuronium or vecuronium when the timing of intubation is judged by clinical criteria

    Br J Anaesth

    (1998)
  • H.J. Sparr et al.

    Influence of induction technique on intubating conditions after rocuronium in adults: Comparison with rapid-sequence induction using thiopentone and suxamenthonium

    Br J Anaesth

    (1996)
  • J.B. Stevens et al.

    A mixture of mivacurium and rocuronium is comparable in clinical onset to succinylcholine

    J Clin Anesth

    (1996)
  • E. Vijayakumar et al.

    The use of neuromuscular blocking agents in the emergency department to facilitate tracheal intubation in the trauma patient: Help or hindrance?

    J Crit Care

    (1998)
  • R.M. Walls

    Management of the difficult airway in the trauma patient

    Emerg Med Clin North Am

    (1998)
  • R.M. Walls

    Rapid sequence intubation in head trauma

    Ann Emerg Med

    (1993)
  • L.O. Warner et al.

    Is intravenous lidocaine an effective adjuvant for endotracheal intubation in children undergoing induction of anesthesia with halothane-nitrous oxide?

    J Clin Anesth

    (1997)
  • J.H. Weiss et al.

    Double-blind comparison of two doses of rocuronium and succinylcholine for rapid-sequence intubation

    J Clin Anesth

    (1997)
  • A. Abdel-Razek et al.

    Nifedipine versus fentanyl to prevent the pressor response to tracheal intubation

    Middle East Journal of Anesthesiology

    (1995)
  • W.Y. Abdulla et al.

    Intraocular pressure changes in response to endotracheal intubation facilitated by atracurium or succinylcholine with or without lidocaine

    Acta Anaesth Belg

    (1992)
  • S. Agoston

    Onset time and evaluation of intubating conditions: Rocuronium in perspective

    Eur J Anesth

    (1995)
  • D.R. Ball

    Propofol infusion for the difficult airway

    Anaesth Intensive Care

    (1997)
  • K.J. Barrington et al.

    Premedication for neonatal intubation

    Am J Perinatol

    (1998)
  • F.A. Berry

    Intramuscular rocuronium in infants and children—is there a need?

    Anesthesiology

    (1996)
  • J.J. Brucia et al.

    The effects of lidocaine on intracranial hypertension

    J Neurosci Nursing

    (1992)
  • K. Bulow et al.

    The effect of topical lignocaine on intubating conditions after propofol-alfentanil induction

    Acta Anaesth Scand

    (1996)
  • H.L. Chee et al.

    The efficacy and safety of mivacurium in children in Singapore

    Singapore Med J

    (1998)
  • C.L. Chiu et al.

    The effect of mivacurium pretreatment on intraocular pressure changes induced by suxamethonium

    Anaesthesia

    (1998)
  • Chung KS, Sinatra RS, Halevy JD, et al: A comparison of fentanyl, esmolol, and their combination for blunting the...
  • D.R. Cook et al.

    Comparison of the neuromuscular effects of mivacurium and suxamethonium in infants and children

    Acta Anaesth Scand

    (1995)
  • G. Dahlgren et al.

    A comparative study of five different techniques to reduce left ventricular dysfunction during endotracheal intubation

    Acta Anaesth Scand

    (1991)
  • D.W. Davies et al.

    Topical anaesthesia of the larynx: Cocaine or lignocaine?

    Eur J Anaesth

    (1992)
  • J.C. De May et al.

    Evaluation of the onset and intubation conditions of rocuronium bromide

    Eur J Anesth

    (1994)
  • C. Diefenbach et al.

    Mivacurium chloride—a comparative profile

    Acta Anaesth Scand

    (1995)
  • A.W. Doenicke et al.

    Onset time, endotracheal intubating conditions, and plasma histamine after cisatracurium and vecuronium administration

    Anesth Analg

    (1998)
  • A.J. England et al.

    Tracheal intubation conditions after one minute:Rocuronium and vecuronium, alone and in combination

    Anesthesiology

    (1997)
  • S.A. Feldman

    Rocuronium—onset times and intubating conditions

    Eur J Anaesth

    (1994)
  • C.K. Feng et al.

    A comparison of lidocaine, fentanyl, and esmolol for attenuation of cardiovascular response to laryngoscopy and tracheal intubation

    Acta Anaesth Sing

    (1996)
  • J.E. Frampton et al.

    Mivacurium: A review of its pharmacology and therapeutic potential in general anaesthesia

    Drugs

    (1993)
  • Y. Fujii et al.

    effects of calcium channel blockers on circulatory response to tracheal intubation in hypertensive patients: Nicardipine versus diltiazem

    Can J Anaesth

    (1995)
  • A. Harsten et al.

    Intubating conditions provided by propofol and alfentanil— acceptable, but not ideal

    Acta Anaesth Scand

    (1997)
  • S.C. Harvey et al.

    A randomized, double-blind comparison of rocuronium, D-tubocurarine, and “mini-dose” succinylcholine for preventing succinylcholine-induced muscle fasciculations

    Anesth Analg

    (1998)
  • S.M. Helfman et al.

    Which drug prevents tachycardia and hypertension associated with tracheal intubation: lidocaine, fentanyl, or esmolol?

    Anesth Analg

    (1991)
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    Address reprint requests to Paula Susanna Wadbrook, MD, Department of Emergency Medicine, Scott & White Medical Center, 2401 South 31st Street, Temple, TX 76508

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