Rapid Sequence Induction

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The rapid sequence induction (RSI, English, for example: "fast flow of the (anesthesia) Introduction") (also rapid sequence induction , flash initiation , ileus introduction , crush intubation and non-fasting initiation ) is a special form of anesthesia . It is used when there is an increased risk for the patient that stomach contents will be vomited or passively flow back ( regurgitation ) and this or other secretions such as blood will get into the airways ( aspiration ). The patient can suffocate or develop life-threatening pneumonia as a resultdevelop. Typical risk constellations include not fasting patients, advanced pregnancy and heavy bleeding in the upper digestive tract; there is an extreme risk with intestinal obstruction ( ileus ), so that the technique is often referred to as ileus induction .

The term Rapid Sequence Induction comes from the fact that the normal sequence (sequence) of intubation is shortened and certain steps are skipped. The aim is to keep the period from loss of consciousness to the securing of the airway through endotracheal intubation as short as possible after the administration of the anesthetic medication, since the medication affects the occlusion of the esophagus (closing force of the upper esophageal sphincter) and the patient's protective reflexes. In a Canadian study from 1966 to 2006, however, no evidence was found for an actual protective effect of the RSI.

Synonyms designations

There are a variety of other names for the RSI, such as rapid sequence induction , Sturzintubation , quick introduction , emergency introduction , non-fasting Introduction , crash intubation or often ileus Introduction

While the term crash induction was previously used in the Anglo-American language area for an emergency initiation, the expression crush induction or crush intubation was widespread in the German language area . This expression is an example of a bogus Anglicism , an English expression that does not exist in the Anglo-American language area.

Areas of application

The rapid sequence induction is pulmonary in all patients with an increased risk aspiration used. This is the case with advanced pregnancy , illnesses or injuries to the gastrointestinal tract and emergency patients with injuries . Various pre-existing conditions such as diabetes mellitus and kidney failure can also delay gastric passage. Patients who have not fasted are also induced using RSI if the recommended waiting periods (six hours for solid foods, two hours for clear liquids such as water, sufficient to ensure that the stomach is emptied) are not guaranteed.

Technique of rapid sequence induction

To reduce the risk of regurgitation , Rapid Sequence Induction is carried out either in the upper body position (30 ° -45 °) of the patient in order to reduce passive regurgitation, or in the head-down position to prevent stomach contents from penetrating the airways, or in a normal supine position in order to achieve the best possible intubation conditions. Especially if there is an obstruction of the intestine, a gastric tube is placed as early as possible in the awake patient with preserved protective reflexes in order to minimize the stomach contents. This can be removed directly before induction of anesthesia so that the lower esophageal sphincter can effectively close and one can preoxygenate better, or it can be left in order to have a better orientation during intubation. In order to be able to quickly remove stomach contents from the throat in an emergency, a running suction device with a large- lumen suction catheter must be kept ready.

As with any induction of anesthesia, the patient is first extensively preoxygenated , he inhales pure oxygen through a ventilation mask. In this way, the nitrogen-rich air in the lungs is largely exchanged for pure oxygen ( denitrogenation ). The body can use the oxygen supply created in this way for several minutes if breathing stops at the beginning of the anesthesia.

In the past, an assistant performed a cricoid pressure (Sellick handle): By applying pressure to the cricoid cartilage of the larynx, the esophagus behind it was compressed, which was supposed to prevent regurgitation . The effectiveness of cricoid pressure has been questioned in the more recent literature, and it may even be associated with an increase in the risk of aspiration. It is no longer used to an increasing extent.

The anesthetic drugs are injected in rapid succession: A opioid (eg. Fentanyl , sufentanil ), a hypnotic (such as etomidate , thiopental or propofol ) and a fast-acting muskelerschlaffendes means ( relaxant , formerly conventionally succinylcholine , now increasingly rocuronium ). The choice of medication can vary according to the indication and doctrine. One difficulty is that the medication cannot be titrated and a good dose estimate is required to avoid unnecessary drops in blood pressure, while at the same time achieving adequate intubation conditions.

The patient falls asleep within a few seconds to less than a minute. Breathing and protective reflexes (coughing, swallowing, choking) stop. If stomach contents get into the throat, the patient is not protected from suffocation or inhalation of the same. To facilitate intubation is a corporate office uses. The patient is quickly intubated endotracheally ; the blocker cuff of the tube in the windpipe is immediately sealed. This prevents blood, saliva or stomach contents from getting into the lungs next to the tube. The airway is thus secured. When the RSI is completed, controlled ventilation is started. If the gag reflex is not or not sufficiently blocked, then vomiting can occur during intubation. To empty the stomach, a nasogastric tube can be inserted again after intubation. This lowers the risk of aspiration during extubation .

While the anesthetist first checks before "normal" intubation after falling asleep, whether mask ventilation is possible without any problems, then gives the relaxant and ventilates the patient with a face mask until the muscles are relaxed, this step is called "intermediate ventilation". skipped at the RSI. This happens because mask ventilation allows air to enter the stomach, which would encourage regurgitation of stomach contents. The necessity of a "test ventilation" before intubation has recently been questioned.

Modifications

While RSI is intended to reduce the risk of aspiration, the procedure accepts the risk of causing a “ cannot-ventilate-cannot-intubate ” situation. In individual cases, especially when there are urgent indications of difficult airway conditions, the anesthetist will deviate from the procedure described in order to weigh up the risks.

Modified RSI in Children

For small children and newborns, the risk of a lack of oxygen is significantly greater than the risk of aspiration. The low oxygen reserves in the lungs ( functional residual capacity ) contrast with a high oxygen demand and high minute ventilation. Therefore, if the child does not use mask ventilation during induction of anesthesia, there would usually be a lack of oxygen. The use of the fast muscle relaxant succinylcholine is problematic in children, as a possibly existing muscle metabolic disease in the child has not yet been established and the administration of succinylcholine could lead to life-threatening malignant hyperthermia . Tilting the table during induction of anesthesia with the aim of reducing the pressure on the stomach or preventing gastric juice from entering the windpipe leads to poorer intubation conditions and thus increases the risk of oxygen deficiency.

The German Society for Anesthesia and Intensive Care Medicine therefore recommends, among other things, with regard to RSI in children:

  • Position on the table with the aim of optimal intubation conditions
  • Introductory medication through previously established venous access
  • no introduction with anesthetic gases via mask
  • Use of non-depolarizing muscle relaxants
  • Do not use succinylcholine
  • No cricoid pressure
  • Mask ventilation during induction of anesthesia
  • Use of a tube with a cuff balloon

literature

Individual evidence

  1. ^ AG Jensen, T. Callesen, JS Hagemo, K. Hreinsson, V. Lund, J Nordmark; Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine: Scandinavian clinical practice guidelines on general anesthesia for emergency situations. In: Acta Anaesthesiol Scand. 54 (8), Sep 2010, pp. 922-950. PMID 20701596 doi: 10.1111 / j.1399-6576.2010.02277.x
  2. ↑ David T. Neilipovitz, Edward T. Crosby: No evidence for Decreased incidence of aspiration after rapid sequence induction. In: Canadian Journal of Anesthesia. 54, 9, 2007, pp. 748-764. PMID 17766743
  3. ↑ German Society for Anaesthesiology and Intensive Care Medicine (DGAI) and Professional Association of German Anesthetists (BDA): Preoperative sobriety requirement for elective interventions. In: Anaesthesiol Intensivmed. 45, 2004, p. 722.
  4. ↑ American Society of Anesthesiologists Task Force on Preoperative Fasting: Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures. In: Anesthesiology. 90, 1999, pp. 896-905.
  5. ↑ D. Steinmann, HJ Priebe: Krikoiddruck. In: Anaesthesiologist. 58 (7), Jul 2009, pp. 695-707. Review. PMID 19554271 ; on this: A. Timmermann, C. Byhahn: Cricoid pressure: protective handle or established nonsense? (Editorial). In: Anaesthesiologist. 58 (7), Jul 2009, pp. 663-664. PMID 19547935 .
  6. ↑ test ventilation before relaxation; Security or Outdated Mindset?
  7. ↑ Recommended Action for Rapid Sequence Induction in Childhood - From the Scientific Working Group on Child Anesthesia of the German Society for Anesthesiology and Intensive Care Medicine (DGAI) In: Anästh Intensivmed. 48, 2007, pp. S88-S93 Aktiv Druck & Verlag GmbH