Rapid sequence induction
Encyclopedia
Rapid Sequence Induction (RSI) is a medical procedure
involving the expeditious induction of general anesthesia
and subsequent intubation of the trachea
. RSI is generally used in an emergency setting or for patients who have an increased risk of aspirating stomach contents into the lungs
. If not performed properly, or if tracheal intubation is not accomplished within a short period of time (usually less than 2 minutes), the patient could suffer extreme morbidity or even death from hypoxia
.
RSI is usually performed by an anesthesiologist
, nurse anesthetist
, emergency department physician
, intensive care physician, or physician assistant
. It may also be performed in the prehospital setting by paramedic
s, including flight medic
s and flight nurse
s.
, such as fentanyl, and then a drug to induce unconsciousness (commonly propofol
). At this point, the patient is manually ventilated for a short period of time before a neuromuscular blocking agent (for example succinylcholine or rocuronium
) is administered and the patient is intubated. During rapid sequence induction, the patient still receives the IV opioid. However, the difference lies in the fact that the induction drug and blocking agent are administered in rapid succession with no time allowed for manual ventilation. In either case, the endotracheal tube is placed shortly after onset of action of the blocking agent. Medications are utilized to allow rapid placement of an endotracheal tube
between the vocal cords
, while the cords are being visualized with the aid of a laryngoscope
. Once the endotracheal tube has been passed between the vocal cords, a cuff is inflated around the tube in the trachea
and the patient can then be artificially ventilated
.
RSI involves preoxygenating the lungs with a tightly-fitting oxygen mask
, followed by the sequential intravenous administration of predetermined doses of a sleep-inducing
drug and a rapid-acting neuromuscular blocking agent. Commonly used hypnotics include thiopental
, propofol
and etomidate
. Commonly used neuromuscular blocking agents used include succinylcholine
and rocuronium. The neuromuscular blocking agents
paralyze all of the skeletal muscles, most notably and importantly in the oropharynx
, larynx
, and diaphragm
. Opioid
s such as fentanyl may be given to attenuate the responses to the intubation process (accelerated heart rate
and increased intracranial pressure
). This is supposed to have advantages in patients with ischemic heart disease
and those with brain injury
(e.g. after traumatic brain injury
or stroke
). Lidocaine is also theorized to blunt a rise in intracranial pressure during laryngoscopy, although this remains controversial and its use varies greatly. Atropine may be used to prevent a reflex bradycardia from vagal stimulation during laryngoscopy, especially in young children and infants. Despite their common use, such adjunctive medications have not been demonstrated to improve outcomes.
One important difference between RSI and routine tracheal intubation is that the practitioner does not manually assist the ventilation of the lungs after the onset of general anesthesia and cessation of breathing
, until the trachea has been intubated and the cuff has been inflated. Another key feature of RSI is the application of manual pressure to the cricoid cartilage, often referred to as the "Sellick maneuver", prior to instrumentation of the airway and intubation of the trachea.
ventilation. Alternative airway management devices must be immediately available, in the event the trachea cannot be intubated using conventional techniques. Such devices include the combitube
and the laryngeal mask airway
. Invasive techniques such as cricothyrotomy
must also be available in the event of inability to intubate the trachea by more conventional techniques.
Named for British anesthetist Brian Arthur Sellick (1918–1996) who first described the procedure in 1961, the goal of the Sellick maneuver is to minimize the possibility of regurgitation and pulmonary aspiration of gastric contents. Cricoid pressure has been widely used during RSI for nearly fifty years, despite a lack of compelling evidence to support this practice. The initial article by Sellick was based on a small sample size at a time when high tidal volume
s, head-down positioning
and barbiturate
anesthesia were the rule. Beginning around 2000, a significant body of evidence has accumulated which questions the effectiveness of the Sellick maneuver. The application of cricoid pressure may in fact displace the esophagus laterally instead of compressing it as described by Sellick. Cricoid pressure may also compress the glottis, which can obstruct the view of the laryngoscopist and actually cause a delay in securing the airway. Some clinicians believe the use of cricoid pressure should be abandoned because of the lack of scientific evidence of benefit and possible complications.
The Sellick maneuver is often confused with the "BURP" (Backwards Upwards Rightwards Pressure) maneuver. While both of these involve digital pressure to the anterior aspect (front) of the laryngeal apparatus, the purpose of the latter is to improve the view of the glottis during laryngoscopy and tracheal intubation, rather than to prevent regurgitation.
Medical procedure
A medical procedure is a course of action intended to achieve a result in the care of persons with health problems.A medical procedure with the intention of determining, measuring or diagnosing a patient condition or parameter is also called a medical test...
involving the expeditious induction of general anesthesia
General anaesthesia
General anaesthesia is a state of unconsciousness and loss of protective reflexes resulting from the administration of one or more general anaesthetic agents...
and subsequent intubation of the trachea
Tracheal intubation
Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs...
. RSI is generally used in an emergency setting or for patients who have an increased risk of aspirating stomach contents into the lungs
Pulmonary aspiration
Pulmonary aspiration is the entry of material from the oropharynx or gastrointestinal tract into the larynx and lower respiratory tract...
. If not performed properly, or if tracheal intubation is not accomplished within a short period of time (usually less than 2 minutes), the patient could suffer extreme morbidity or even death from hypoxia
Hypoxia (medical)
Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
.
RSI is usually performed by an anesthesiologist
Anesthesiologist
An anesthesiologist or anaesthetist is a physician trained in anesthesia and peri-operative medicine....
, nurse anesthetist
Nurse anesthetist
A nurse anesthetist is a nurse who specializes in the administration of anesthesia.In the United States, a Certified Registered Nurse Anesthetist is an advanced practice registered nurse who has acquired graduate-level education and board certification in anesthesia...
, emergency department physician
Emergency physician
An emergency physician is a physician who works at an emergency department to care for acutely ill patients. The emergency physician is a specialist in advanced cardiac life support , trauma care such as fractures and soft tissue injuries, and management of other life-threatening situations.In...
, intensive care physician, or physician assistant
Physician assistant
A physician assistant/associate ' is a healthcare professional trained and licensed to practice medicine with limited supervision by a physician.-General description:...
. It may also be performed in the prehospital setting by paramedic
Paramedic
A paramedic is a healthcare professional that works in emergency medical situations. Paramedics provide advanced levels of care for medical emergencies and trauma. The majority of paramedics are based in the field in ambulances, emergency response vehicles, or in specialist mobile units such as...
s, including flight medic
Flight medic
A Flight Medic is a generic term used to describe a Paramedic that functions in an aeromedical environment. Typically the Flight Medic will work with a registered nurse, physician, Respiratory Therapist, or another Paramedic. The Flight Paramedic is usually highly trained and has years of clinical...
s and flight nurse
Flight nurse
A Flight Nurse is traditionally a specialty where highly trained Registered Nurses provide comprehensive prehospital and emergency and critical care to all types of patients during aeromedical evacuation or rescue operations aboard helicopter and propeller aircraft or jet aircraft.Flight Nurses are...
s.
Technique
RSI refers to the pharmacologically induced sedation and neuromuscular paralysis prior to intubation of the trachea. The technique is a quicker form of the process normally used to induce general anesthesia. With standard intravenous induction of general anesthesia, the patient typically receives an opioidOpioid
An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...
, such as fentanyl, and then a drug to induce unconsciousness (commonly propofol
Propofol
Propofol is a short-acting, intravenously administered hypnotic agent. Its uses include the induction and maintenance of general anesthesia, sedation for mechanically ventilated adults, and procedural sedation. Propofol is also commonly used in veterinary medicine...
). At this point, the patient is manually ventilated for a short period of time before a neuromuscular blocking agent (for example succinylcholine or rocuronium
Rocuronium
Rocuronium is an aminosteroid non-depolarizing neuromuscular blocker or muscle relaxant used in modern anaesthesia, to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation.Introduced in 1994, rocuronium has...
) is administered and the patient is intubated. During rapid sequence induction, the patient still receives the IV opioid. However, the difference lies in the fact that the induction drug and blocking agent are administered in rapid succession with no time allowed for manual ventilation. In either case, the endotracheal tube is placed shortly after onset of action of the blocking agent. Medications are utilized to allow rapid placement of an endotracheal tube
Tracheal tube
A tracheal tube is a catheter that is inserted into the trachea in order for the primary purpose of establishing and maintaining a patent airway and to ensure the adequate exchange of oxygen and carbon dioxide. Many different types of tracheal tubes are available, suited for different specific...
between the vocal cords
Vocal folds
The vocal folds, also known commonly as vocal cords, are composed of twin infoldings of mucous membrane stretched horizontally across the larynx...
, while the cords are being visualized with the aid of a laryngoscope
Laryngoscopy
Laryngoscopy is a medical procedure that is used to obtain a view of the vocal folds and the glottis. Laryngoscopy may be performed to facilitate tracheal intubation during general anesthesia or cardiopulmonary resuscitation or for procedures on the larynx or other parts of the upper...
. Once the endotracheal tube has been passed between the vocal cords, a cuff is inflated around the tube in the trachea
Vertebrate trachea
In tetrapod anatomy the trachea, or windpipe, is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet cells that produce mucus...
and the patient can then be artificially ventilated
Artificial respiration
Artificial respiration is the act of assisting or stimulating respiration, a metabolic process referring to the overall exchange of gases in the body by pulmonary ventilation, external respiration, and internal respiration...
.
RSI involves preoxygenating the lungs with a tightly-fitting oxygen mask
Oxygen mask
An oxygen mask provides a method to transfer breathing oxygen gas from a storage tank to the lungs. Oxygen masks may cover the nose and mouth or the entire face...
, followed by the sequential intravenous administration of predetermined doses of a sleep-inducing
Hypnotic
Hypnotic drugs are a class of psychoactives whose primary function is to induce sleep and to be used in the treatment of insomnia and in surgical anesthesia...
drug and a rapid-acting neuromuscular blocking agent. Commonly used hypnotics include thiopental
Sodium thiopental
Sodium thiopental, better known as Sodium Pentothal , thiopental, thiopentone sodium, or Trapanal , is a rapid-onset short-acting barbiturate general anaesthetic...
, propofol
Propofol
Propofol is a short-acting, intravenously administered hypnotic agent. Its uses include the induction and maintenance of general anesthesia, sedation for mechanically ventilated adults, and procedural sedation. Propofol is also commonly used in veterinary medicine...
and etomidate
Etomidate
Etomidate is a short acting intravenous anaesthetic agent used for the induction of general anaesthesia and for sedation for short procedures such as reduction of dislocated joints, tracheal intubation and cardioversion...
. Commonly used neuromuscular blocking agents used include succinylcholine
Suxamethonium chloride
Suxamethonium chloride , also known as suxamethonium or succinylcholine, is a paralytic drug used to induce muscle relaxation and short-term paralysis, usually to facilitate tracheal intubation. Suxamethonium is sold under the trade names Anectine, Quelicin, and Scoline. It is used as a paralytic...
and rocuronium. The neuromuscular blocking agents
Neuromuscular-blocking drug
Neuromuscular-blocking drugs block neuromuscular transmission at the neuromuscular junction, causing paralysis of the affected skeletal muscles. This is accomplished either by acting presynaptically via the inhibition of acetylcholine synthesis or release or by acting postsynaptically at the...
paralyze all of the skeletal muscles, most notably and importantly in the oropharynx
Oropharynx
The Oropharynx reaches from the Uvula to the level of the hyoid bone.It opens anteriorly, through the isthmus faucium, into the mouth, while in its lateral wall, between the two palatine arches, is the palatine tonsil....
, larynx
Larynx
The larynx , commonly called the voice box, is an organ in the neck of amphibians, reptiles and mammals involved in breathing, sound production, and protecting the trachea against food aspiration. It manipulates pitch and volume...
, and diaphragm
Thoracic diaphragm
In the anatomy of mammals, the thoracic diaphragm, or simply the diaphragm , is a sheet of internal skeletal muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in respiration...
. Opioid
Opioid
An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...
s such as fentanyl may be given to attenuate the responses to the intubation process (accelerated heart rate
Tachycardia
Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
and increased intracranial pressure
Intracranial pressure
Intracranial pressure is the pressure inside the skull and thus in the brain tissue and cerebrospinal fluid . The body has various mechanisms by which it keeps the ICP stable, with CSF pressures varying by about 1 mmHg in normal adults through shifts in production and absorption of CSF...
). This is supposed to have advantages in patients with ischemic heart disease
Ischaemic heart disease
Ischaemic or ischemic heart disease , or myocardial ischaemia, is a disease characterized by ischaemia of the heart muscle, usually due to coronary artery disease...
and those with brain injury
Brain injury
A brain injury is any injury occurring in the brain of a living organism. Brain injuries can be classified along several dimensions. Primary and secondary brain injury are ways to classify the injury processes that occur in brain injury, while focal and diffuse brain injury are ways to classify...
(e.g. after traumatic brain injury
Traumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...
or stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
). Lidocaine is also theorized to blunt a rise in intracranial pressure during laryngoscopy, although this remains controversial and its use varies greatly. Atropine may be used to prevent a reflex bradycardia from vagal stimulation during laryngoscopy, especially in young children and infants. Despite their common use, such adjunctive medications have not been demonstrated to improve outcomes.
One important difference between RSI and routine tracheal intubation is that the practitioner does not manually assist the ventilation of the lungs after the onset of general anesthesia and cessation of breathing
Apnea
Apnea, apnoea, or apnœa is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged...
, until the trachea has been intubated and the cuff has been inflated. Another key feature of RSI is the application of manual pressure to the cricoid cartilage, often referred to as the "Sellick maneuver", prior to instrumentation of the airway and intubation of the trachea.
Additional considerations
The clinician that performs RSI must be skilled in tracheal intubation and also in bag valve maskBag valve mask
A bag valve mask is a hand-held device used to provide positive pressure ventilation to a patient who is not breathing or who is breathing inadequately. The device is a normal part of a resuscitation kit for trained professionals, such as ambulance crew...
ventilation. Alternative airway management devices must be immediately available, in the event the trachea cannot be intubated using conventional techniques. Such devices include the combitube
Combitube
The Combitube is a blind insertion airway device often used in the pre-hospital, emergency setting. It is designed to facilitate the tracheal intubation of a patient in respiratory distress. It consists of a cuffed, double-lumen tube that is inserted into a the patient's airway facilitating...
and the laryngeal mask airway
Laryngeal mask airway
The laryngeal mask airway is a supraglottic airway device invented by Archie Brain, a British anaesthetist.-Description:Laryngeal masks consist of a tube with an inflatable cuff that is inserted into the pharynx. Laryngeal mask airways come in a variety of sizes ranging from large adult to infant...
. Invasive techniques such as cricothyrotomy
Cricothyrotomy
A cricothyrotomy is an incision made through the skin and cricothyroid membrane to establish a patent airway during certain life-threatening situations, such as airway obstruction by a foreign body, angioedema, or massive...
must also be available in the event of inability to intubate the trachea by more conventional techniques.
Controversy
Since the introduction of RSI, there has been controversy regarding virtually every aspect of this technique, including:- choice of intravenous hypnotic agents as well as their dosage and timing of administration
- dosage and timing of administration of neuromuscular blocking agents
- avoidance of manual ventilation before tracheal intubation
- optimal position and whether the head-up, head-down, or horizontal supine position is the safest for induction of anesthesia in full-stomach patients
- application of cricoid pressure (the Sellick maneuver)
Named for British anesthetist Brian Arthur Sellick (1918–1996) who first described the procedure in 1961, the goal of the Sellick maneuver is to minimize the possibility of regurgitation and pulmonary aspiration of gastric contents. Cricoid pressure has been widely used during RSI for nearly fifty years, despite a lack of compelling evidence to support this practice. The initial article by Sellick was based on a small sample size at a time when high tidal volume
Tidal volume
Tidal volume is the lung volume representing the normal volume of air displaced between normal inspiration and expiration when extra effort is not applied.Typical values are around 500ml or 7ml/kg bodyweight.-Mechanical Ventilation:...
s, head-down positioning
Trendelenburg position
In the Trendelenburg position the body is laid flat on the back with the feet higher than the head by 15-30 degrees, in contrast to the reverse Trendelenburg position, where the body is tilted in the opposite direction. This is a standard position used in abdominal and gynecological surgery...
and barbiturate
Barbiturate
Barbiturates are drugs that act as central nervous system depressants, and can therefore produce a wide spectrum of effects, from mild sedation to total anesthesia. They are also effective as anxiolytics, as hypnotics, and as anticonvulsants...
anesthesia were the rule. Beginning around 2000, a significant body of evidence has accumulated which questions the effectiveness of the Sellick maneuver. The application of cricoid pressure may in fact displace the esophagus laterally instead of compressing it as described by Sellick. Cricoid pressure may also compress the glottis, which can obstruct the view of the laryngoscopist and actually cause a delay in securing the airway. Some clinicians believe the use of cricoid pressure should be abandoned because of the lack of scientific evidence of benefit and possible complications.
The Sellick maneuver is often confused with the "BURP" (Backwards Upwards Rightwards Pressure) maneuver. While both of these involve digital pressure to the anterior aspect (front) of the laryngeal apparatus, the purpose of the latter is to improve the view of the glottis during laryngoscopy and tracheal intubation, rather than to prevent regurgitation.