Why rapid sequence intubation

This is essentially procedural sedation to achieve suitable conditions for induction of anaesthesia. This technique is in conflict with traditional RSI where no agents are administered before induction but was described in UK pre-hospital anaesthesia guidelines in and again in [ 18 ]. A safety feature of the technique is that sedation is only administered when preparation for RSI is completed. Cricoid pressure was introduced into clinical practice as a key element of RSI in , based mainly on a small case series on cadavers [ 1 ].

It is used to compress the oesophagus and prevent regurgitation of gastric contents until the airway is secured with a tracheal tube.

Many anaesthetists also use it to manipulate the upper airway to improve laryngeal view. There is a growing scepticism about the efficacy of cricoid pressure during emergency anaesthesia. A Cochrane review published in noted the lack of high quality evidence on the subject but acknowledged that what evidence there was did not strongly support the intervention [ 51 ].

Subsequently a multicentre randomized, double-blind, study conducted in the US was published in and demonstrated that in patients who had emergency RSI the use of cricoid pressure did not reduce the incidence of aspiration. It also suggested that intubation was more difficult in the cricoid pressure group [ 52 ]. There is a school of thought that if cricoid pressure is used it may inhibit air entry into the stomach. Therefore ventilation during the apnoeic period following drug administration may be less likely to provoke aspiration.

The UK is one of only a few countries with a high use of cricoid pressure particularly compared to other European countries [ 53 ]. UK DAS guidelines recommend the early removal of cricoid pressure if there is a difficult laryngoscopy [ 37 ].

Other national and international guidelines including those by the European Resuscitation Council, Scandinavian Clinical Practice Guidelines, and German Airway Management Guidelines do not support its use [ 54 , 55 , 56 ].

The use of cricoid pressure as an essential component of RSI is decreasing. When it is used it is widely recommended that it should be rapidly released in the event of a poor view at laryngoscopy. There is recognition that the balance of risk between aspiration and hypoxia was not addressed by the traditional RSI method.

This is particularly important for critically ill patients who are at high risk of becoming hypoxic during the apnoeic period of induction [ 57 ]. This has led to the development of simple techniques to maintain oxygenation. The development of transnasal humidified rapid-insufflation ventilatory exchange THRIVE has also been used to maintain oxygenation although mostly in the operating theatre environment [ 60 , 61 ]. In non-operating theatre environments, it has been clearly demonstrated that apnoeic oxygenation is straightforward to deliver.

Where the airway is patent it would be fully expected to increase the time to desaturation and this has been confirmed in the pre-hospital environment [ 62 ]. Unfortunately, clear benefit has not been demonstrated in more recent studies [ 63 , 64 ]. On the basis that apnoeic oxygenation is likely to delay the onset of hypoxaemia in some patient groups and is easy to deliver, it is likely to continue to be used in emergency practice.

A different approach to the prevention of hypoxia in the apnoeic period is to avoid apnoea during induction altogether. A large multicentre trial showed that gentle bag valve mask ventilation between induction and laryngoscopy reduced the incidence of hypoxia without adversely affecting aspiration rates [ 65 ]. This practice may already have been commonplace.

Another simple technique to improve oxygenation during emergency anaesthesia is to optimise patient positioning. In addition to improving oxygenation a head up position has been recommended to prevent aspiration and improve intubation success [ 38 ].

The authors were unable to demonstrate any benefits in oxygenation and also reported significantly worse laryngoscopic views and increased intubation difficulty [ 66 ]. The benefits or disadvantages of a head up position are not therefore clear.

There are other positioning considerations which can also influence intubation difficulty including removal of cervical collars and ensuring, in the pre-hospital environment, degree access to the patient and the use of an ambulance trolley at waist height to optimise laryngoscopy attempts [ 18 ].

The ability to tip a trolley is also desirable [ 10 ]. Simple strategies to maintain oxygenation and improve the laryngoscopic view have been incorporated into emergency RSI techniques.

Although the benefits have not been straightforward to establish, the available evidence suggests that adaptations do not cause increased risk of complications such as aspiration. The increasing availability and portability of video laryngoscopes has led to a significant increase in their use in emergency anaesthesia including in emergency departments and pre-hospital care. A Cochrane review published in examined over 60 studies and concluded that video laryngoscopy can improve laryngoscopic view and reduce failed intubation rates particularly in patients with difficult airways.

Only three studies included emergency patients [ 67 ]. The published evidence for the value of video laryngoscopy over direct laryngoscopy in emergency anaesthesia is inconclusive and the quality of available evidence is low [ 67 ].

Indeed, one study showed no difference between direct and video laryngoscopy in survival to hospital discharge in trauma patients and showed a longer median time to intubation; sub-group analysis of severe head injury patients seemed to be associated with a greater incidence of hypoxia during the intubation attempt [ 68 ]. There is however consensus that, in the airway management of critically ill patients videolaryngoscopy should be immediately available [ 38 ].

The benefits of availability were confirmed in a recent randomised pre-hospital study which found both direct and indirect laryngoscopy to be equally effective but reported that swapping from one technique to the other was more successful than a second attempt with the same device [ 69 ]. Despite the fact that intubation difficulties are more likely to occur outside the operating theatre environment a recent survey reported that video laryngoscopes are most commonly available in operating rooms and less so in the areas where emergency anaesthesia is performed outside the operating room [ 70 ].

The potential risks of transmission of infection during emergency intubation have been brought into sharp focus during the COVID pandemic. UK guidelines recommend videolaryngoscopy as the first line option for emergency intubation in high risk patients [ 71 ]. Since the description of RSI the use of an intubating bougie has become standard UK practice to optimise the first attempt of emergency tracheal intubation during both direct and video laryngoscopy [ 19 , 72 , 73 ].

The simple device is used variably in other countries, but some recent high-quality studies have demonstrated superiority over other intubation techniques [ 74 ]. Advances in the standard of monitoring equipment have transformed the conduct of emergency anaesthesia.

There are well developed minimum monitoring national standards in place for elective and emergency anaesthesia and almost identical standards are recommended for pre-hospital anaesthesia [ 18 ].

The use of capnography to detect oesophageal intubation is a key improvement in the conduct of RSI and has been identified as a vital tool in the prevention of life threatening complications in emergency intubation [ 15 , 75 ].

In patients requiring neuroprotection, invasive blood pressure monitoring may be indicated to prevent both hypo and hypertension [ 76 ]. The developments in equipment, monitoring and techniques have made failed intubation after RSI less common. When intubation does fail rescue techniques have developed to make poor outcomes less likely. Recent studies have also suggested a fall in the rates of rescue surgical airway both in emergency departments [ 77 ] and in pre-hospital practice [ 78 ].

In most well-resourced hospitals and emergency medical systems the conduct of RSI is subject to multiple governance processes which were not present when RSI was introduced. Training, supervision, guidelines, and incident reporting are just some of the governance elements which aim to deliver safer emergency anaesthesia.

Registries and databases provide information to guide quality improvement and major multicentre national audit projects have identified key areas for improvement of the RSI process, particularly around airway complications and awareness [ 15 , 39 ].

More recently this activity has extended to more the difficult areas of emergency anaesthesia in the emergency department and in pre-hospital care [ 14 ] and individual services have adopted quality improvement recommendations such as key performance indicators for pre-hospital anaesthesia [ 75 ].

In many respects the conduct of RSI in current emergency practice is far removed from the original descriptions of the procedure. Changes to the procedure have tackled several considerations less well addressed by the original technique including reducing the frequency and severity of hypoxaemia, reducing the frequency of failed intubation and making detection and management of complications more effective.

The remarkable consensus in RSI practice that persisted for many years has lessened in recent years. Despite this, standardisation is often in place in many systems.

It is difficult to know whether variations in practice are necessary to deliver tailored care to different patient groups or whether increased consistency has the potential to improve overall patient safety. In in-hospital practice it has been suggested that avoidance of adverse events and successful intubation of critically ill patients on the first attempt can be positively influenced by operator related factors including training and experience, equipment selection and drug choices [ 79 ].

Limiting choice and delivering a very standard RSI might be more appropriate when RSI is delivered by less experienced operators in more austere environments [ 14 ]. One consistency in high performing systems is the recognition that the delivery of high-quality RSI is not a solo activity and requires an effective team approach to apply the appropriate techniques.

In addition, attention to all factors in RSI delivery is important. Systems reporting improvement rarely introduce or change only one component of the procedure. The safety of RSI is as important now as it was when first described. It is carried out on our sickest and most unstable patients in all emergency treatment areas. Choices of drugs and techniques have rapidly increased and many of these changes have the potential to improve safety. Providers of RSI now have a wide range of tools and techniques available to enhance the basic procedure.

These can be incorporated into a structured plan to deliver safe emergency anaesthesia to their particular patient casemix.

Data sharing not applicable to this article as no datasets were generated or analysed during the current study. Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia. Mendelson CL. The aspiration of stomach contents into the lungs during obstetric anesthesia. Am J Obstet Gynecol.

Opioid-induced apnoea can hinder the recovery of spontaneous respiration after failed intubation. Short-acting drugs, such as alfentanil and remifentanil have short half-lives and are rapidly removed from the circulation.

This results in rapid offset of action. Furthermore, the opioid receptor antagonist naloxone can be used as an i. Several alternatives to opioids exist that may exert some of their beneficial effects during intubation and RSI.

Cricoid pressure was first described in Head and neck extension increases the anterior convexity of the cervical spine, stretches the oesophagus and prevents lateral movement of the oesophagus.

Pressure of 20 N 2 kg weight is applied by an assistant with thumb and finger either side of the cricoid cartilage. This is maintained until after intubation and cuff inflation. Studies of the efficacy of cricoid pressure show varying success in preventing regurgitation. In Sellick's original study of 26 high-risk inductions, there were three cases of immediate regurgitation of gastric or oesophageal contents after release of pressure, suggesting that the procedure was effective at preventing regurgitation.

Refinements to the original technique have quantified the timing and amount of pressure applied and also recognized that for the technique to be successful an assistant needs to be trained in application of cricoid pressure and use the skill regularly. It is imperative that the potential complications of performing RSI are appreciated before undertaking the procedure.

The major risk stems from intubation without ascertaining whether it is possible to ventilate the patient. This can result in failure to ventilate a paralysed patient. Each anaesthetist needs to have a plan of action for this situation. Similarly, there is potential for a failed intubation and the need to wake the patient. Ideally this should be done whilst maintaining cricoid pressure to protect the airway. The drugs most commonly used for RSI have relatively high incidences of anaphylaxis; the anaesthetist must be able to treat anaphylaxis and support a compromised patient.

The risk of awareness during the procedure is unlikely to have a dangerous outcome but is very distressing for patients. The complications of cricoid pressure application include failure to occlude the oesophagus, distortion of the larynx disrupting the view at laryngoscopy and, less commonly, oesophageal rupture during active vomiting.

If active vomiting rather than passive regurgitation occurs the cricoid pressure should be released. Attention to detail is required during antagonism of anaesthesia in patients who have required RSI. It is during the transition from deep anaesthesia to full consciousness and vice versa that the risk of aspiration is greatest. The patient should be completely awake and performing purposeful movements or responding to commands before extubation. This confirms that the patient can protect their own airway on removal of the cuffed tube.

Positioning the patient in a sitting position or in the left lateral position further protects the airway in the event of regurgitation. See multiple choice questions 34— Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia.

Lancet ; 2 : Morris J, Cook TM. Rapid sequence induction: a national survey of practice. Mendelson CL. The aspiration of stomach contents into the lungs during obstetric anaesthesia. Am J Obstet Gynaecol ; 52 : — Clinical significance of pulmonary aspiration in the perioperative period. Anaesthesiology ; 78 : 56 — It demonstrates a classic problem in any field including anesthesiology: Effective communication.

It seems that any effort to clearly delineate the efficacy of any of these techniques needs to start with the development of agreeable definitions. Furthermore, the wide variation in practice demonstrated by this survey included many factors including the choice of neuromuscular blocking agent, the oxygen saturation level, at which bag-valve-mask ventilation would be initiated and the application of cricoid pressure.

This variability is not unexpected given the lack of evidence-based trials to answer these questions. National Center for Biotechnology Information , U.

Journal List Saudi J Anaesth v. Saudi J Anaesth. Joseph D. Author information Copyright and License information Disclaimer. Address for correspondence: Dr. E-mail: gro. This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.

This article has been cited by other articles in PMC. Mendelson CL. The aspiration of stomach contents into the lungs during obstetric anesthesia. Am J Obstet Gynecol. Abdulla S. Pulmonary aspiration in perioperative medicine.

Pretreatment done a few minutes prior to induction and paralysis is meant to mitigate the physiological response of the body to the procedure, as a catecholamine surge can result in increased sympathetic activity elevated heart rate and blood pressure , increased intracranial pressure, and bronchospasm.

Some emergency physicians may pretreat with lidocaine or fentanyl in trauma patients who might already have increased intracranial pressure. Some may also consider pretreatment with atropine in children less than 1 year of age. Place towels, blanket, or a wedge under the head until the ears align with suprasternal notch.

Visualize vocal cords, ask to be handed the ET tube without taking your eyes off the cords, and watch for passage through cords. Then, inflate the cuff. Confirm proper placement. This can be done through auscultation of bilateral breath sounds, watching for equal chest rise, and end tidal CO2 the gold standard.

Next is securing the tube, placing on the ventilator, obtaining a confirmatory chest x-ray, and determining a post-intubation sedation plan. Hopefully this bare-bones approach to RSI is enough to get you acquainted with the process, terminology, and medications.

The more you demonstrate a general knowledge of the procedure, the more likely it is that you will have the opportunity to intubate someone yourself as a medical student. Rapid Sequence Intubation Pharmacology. Special thanks to Abby Cosgrove, MD, for reviewing this clinical article.

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