[Crisis event] Sudden laryngospasm during perianaesthesia

Click on the "blue word" to follow us! 28 Sudden laryngospasm during peri-anesthesia 01 Occurrence and harm of sudden laryngospasm during peri-anesthesia The door is partially or completely closed, or the epiglottis cartilage relaxes and collapses to cover the glottis (common in children), causing patients to suddenly experience varying degrees of dyspnea or even complete airway obstruction
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Acute laryngospasm during peri-anesthesia is prone to occur during anesthesia induction and recovery, especially in children.
It is the most common cause of upper airway obstruction and a serious complication during anesthesia
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Olsson et al.
collected 136,929 patients, and the incidence of laryngospasm was 8.
7‰
.

The incidence of laryngospasm in high-risk surgery (eg, otorhinolaryngology surgery) ranges from 1/1000 to 20/100, and many factors increase its incidence, including surgical procedures, anesthesia procedures, and patient-related factors
.

1.
Age Young age is the most important risk factor for laryngospasm
.

In the literature (n = 136 adults, 929 children), the incidence of laryngospasm in children aged 0-9 was 1.
7%, and only 0.
9% in adults and older children
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Preschool children have the highest incidence (>2%)
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Recent data suggest that the overall incidence of laryngospasm is decreasing, but the incidence remains significant in younger patients: 50%-68% occur in children under 5 years of age
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The incidence of intraoperative airway injury events decreased by 8% with each additional year of age, and a recent large population study confirmed the inverse relationship, which showed that the incidence of laryngospasm decreased with each additional year of age by 11%.
%
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2.
Children with upper respiratory tract infection with upper respiratory tract infection can increase the incidence of laryngospasm by 2-5 times.
Anesthesiologists should pay more attention to infant patients in the management of pediatric surgery, especially patients with respiratory syncytial virus infection.
son
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In children, airway (trachea and bronchi) responsiveness increases after upper respiratory tract infection and persists beyond the duration of viral infection
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After 1-2 weeks of infection, the respiratory mucosal epithelium has healed, but the increased airway sensitivity caused by the virus will last for more than 6-8 weeks
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In elective surgery, surgery should be postponed when body temperature >38°C and viscous or purulent secretions are present in the respiratory tract
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3.
Smoking exposure In otolaryngology surgery, children exposed to smoking environment can increase the incidence of laryngospasm by 0.
9%-9.
4%
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4.
Factors related to surgical operation The incidence of laryngospasm is the highest in the operation and operation of the larynx, and the probability of laryngospasm in children's tonsillectomy is more than 20%, and the highest is 26.
5%
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The incidence of emergency surgical procedures is higher than that of elective procedures
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5.
Factors related to anesthesia operation Insufficient depth of anesthesia is the main reason for laryngospasm
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Any stimulation of the superior laryngeal nerve can cause laryngospasm, including oral secretions during anesthesia, bloody sputum, insertion of oropharyngeal airways, sputum suction, and laryngoscopy that can trigger the laryngeal reflex
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Other low-risk factors include intravenous induction, mask ventilation, and maintenance of inhaled anesthetics
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Anesthesia induction and recovery are critical periods associated with laryngospasm
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Some authors consider the latter to be more critical, possibly due to improvements in some procedural practices during induction, the use of laryngeal masks and propofol, and other new inhaled drugs, which have reduced the incidence of laryngospasm during induction
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After the occurrence of acute laryngospasm during the peri-anesthesia period, the negative pressure in the alveoli directly reduces the hydrostatic pressure of the pulmonary interstitium, thereby affecting the permeability of the alveolar capillaries and interfering with the normal physiological functions of the cardiovascular system, such as increasing the filling of the right heart and reducing the left heart.
Filling, increasing left ventricular afterload, and reducing left ventricular ejection increase pulmonary capillary hydrostatic pressure, thereby increasing pulmonary capillary permeability and allowing fluid to enter the pulmonary interstitium
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Life-threatening complications include severe hypoxia, bradycardia, negative pressure pulmonary edema, and asystole
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Laryngeal spasm remains the leading cause of perioperative cardiac arrest of respiratory origin
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02 Analysis of the causes of sudden laryngospasm during peri-anesthesia 01 Pathophysiology of laryngospasm The upper airway has many functions (swallowing, breathing, and pronunciation), but protecting the airway from foreign objects is still the most important, and this function involves many upper airway function
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The laryngeal closing reflex (the laryngeal closure reflex) includes vocal cord contraction, breath-holding, swallowing and coughing
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Upper airway reflex-related neural pathways include an afferent pathway, a common central center, and an efferent pathway
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(1) Afferent pathway: The receptor localization of different reflexes includes the pharyngeal mucosa-glossopharyngeal reflex, the supraglottic laryngeal sealing reflex, the laryngeal trachea-cough reflex, and any part of the upper respiratory tract (except the nose)-apnea
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Many receptors are involved in the laryngeal sealing reflex, and these receptors are sensitive to factors such as colds, stress, laryngeal movements, and chemical etiologies
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Among them, chemoreceptors are sensitive to low oxygen, high potassium liquid and strong acid and alkali liquid
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The afferent pathways include the trigeminal nerve of the nasopharynx, the glossopharyngeal nerve of the oropharynx and subgloss, the superior and recurrent laryngeal nerves, and the branches of the vagus nerves that innervate the larynx and trachea
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The afferent pathway of the laryngeal closure reflex is the superior laryngeal nerve
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(2) Common central center: The afferent pathways of reflexes converge in the nucleus tractus solitarius of the brainstem, which is not only the center of the afferent pathways but also the necessary interneurons for the origin of the upper airway reflexes
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The regulation and programming center of the upper airway reflex is located in the medulla oblongata neuron network, and the function of this center is poorly understood
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Higher-order centers appear to regulate upper airway reflexes, such as coughing that can be suppressed by free consciousness
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(3) Efferent pathway: The main effector is the respiratory muscles (diaphragm and intercostal muscles)
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The laryngeal sealing reflex is responsible for the contraction of the vocal cords.
The muscles involved in the laryngeal muscles are the transverse cricoarytenoid cartilage, the cricothyroid cartilage, and the cricothyroid cartilage
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Stimulation of the upper airway mucosa produces cardiovascular reflexes (changes in arterial pressure and bradycardia) and bronchial tone reflex, suggesting that not only skeletal but also smooth muscle is involved in the upper airway reflex
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02 Causes of laryngospasm It is generally believed that the common causes and precipitating factors of acute laryngospasm in the peri-anesthesia period are as follows
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(1) Patient's own factors: In patients with bronchial asthma or chronic airway inflammation, their respiratory mucosa is more sensitive to various adverse stimuli, and any external stimuli can induce laryngospasm in clinical practice
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The probability of laryngospasm in patients with allergic constitution and airway hyperresponsiveness is higher than that in general patients
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(2) Throat irritation: Reflex laryngospasm caused by irritation of the throat is the most common
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Such as: ① pharyngeal foreign body or tumor to stimulate the larynx
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②Coughing, nausea, hiccups, swallowing, etc.
induce laryngospasm
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③Induced by stimuli such as blood in the airway, secretions, vomiting, or refluxed gastric contents
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④ Intra-airway operation under light anesthesia: Too shallow anesthesia is an important cause of laryngospasm during anesthesia
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The larynx is highly irritable under light anesthesia, and laryngospasm can be induced by direct stimulation of the throat or stimulation at sensitive parts of the body at a distance
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Throat irritation caused by suction, placement of oropharyngeal or nasopharyngeal airways, endotracheal intubation or extubation under light anesthesia
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(3) Inhalation of irritating volatile anesthetics (such as ether) or electrocautery or laser cutting in the oral cavity and nasopharyngeal cavity
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(4) Anesthetics such as sodium thiopental, ketamine hydrochloride, sodium oxybate, atracurium, etc.
that excite the vagus nerve, increase respiratory secretions, and promote the release of histamine are used
.

(5) Hypoxia and carbon dioxide accumulation caused by the failure of the breathing circuit of the anesthesia machine
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(6) Allergies, such as: blood transfusion, infusion reaction,
etc.

(7) Surgical operation stimulation: non-tracheal intubation under shallow general anesthesia, eye, head and neck, periosteum stripping, anus expansion, internal organ traction,
etc.

(8) Moving patients under light anesthesia: especially after intramuscular injection of ketamine in children with high throat sensitivity
.

(9) Central nervous system diseases: such as bulbar palsy, rabies, tetanus, epilepsy,
etc.

(10) Thyroid surgery
.

(11) Hypocalcemia (increased neuromuscular excitability)
.

03 Coping strategies for sudden laryngospasm during peri-anesthesia 01 Diagnosis of sudden laryngospasm during peri-anesthesia The diagnosis of laryngospasm often depends on the clinical diagnosis of anesthesiologists
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Defined as complete or partial airway obstruction combined with a compensatory increase in abdominal and chest wall respiratory amplitude against a closed glottis
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(1) Partial laryngospasm: the "three concave sign" is obvious, the suprasternal fossa, the supraclavicular fossa, and the intercostal space have obvious depressions, abnormal breathing movements of the chest wall and abdominal breathing can be seen, and inspiratory wheezing may be heard.

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(2) Complete laryngospasm: no respiratory movement: no breath sounds; the breathing sac connected to the ventilator does not move, inspiratory wheezing cannot be heard; flat end-expiratory CO2 partial pressure; persistent obstruction may not be relieved Lead to SpO2 drop, cyanosis and bradycardia
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02 Prevention of sudden laryngospasm during peri-anesthesia Identifying risk factors for laryngospasm and formulating a reasonable anesthesia management plan can effectively reduce the incidence and severity of laryngospasm
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(1) Preoperative preparation: understanding the medical history is the most important
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It is traditionally believed that children with upper respiratory tract infection should undergo elective surgery after 4-6 weeks.
However, children <3 years old have 5-10 upper respiratory tract infections per year, so the safety window for general anesthesia management will be very short
.

Von Ungem et al believed that children with cold symptoms on the day of surgery or within 2 weeks increased the risk of laryngospasm, which was confirmed by the latest clinical study (n=9297)
.

Surgery is considered safe 2-3 weeks after the symptoms of the upper respiratory tract appear, and it is also suitable for patients whose upper respiratory tract infection is expected to recur after otolaryngology surgery
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Preoperative administration of anticholinergics may reduce secretions, but there is no evidence that it has an effect on the incidence of laryngospasm (2) Anesthesia plan ① Airway management: Manual ventilation is the main factor causing laryngospasm when the depth of anesthesia is insufficient
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In children with upper respiratory tract infection, endotracheal intubation (ETT) increased the incidence of respiratory adverse events by 11 times compared with face mask ventilation, and laryngeal mask (LMA) application was associated with a lower incidence of respiratory adverse events than endotracheal intubation , so less invasive airway stimulation can reduce its incidence
.

The latest prospective study shows that both laryngeal mask and endotracheal intubation increase the incidence of laryngospasm compared with face mask ventilation
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②Induction period: the risk of laryngospasm increased by inhalation drug or intravenous drug is still controversial
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Experiments in 2-6-year-old children with increased airway reactivity showed that the laryngeal respiratory reflex was induced differently by sevoflurane and propofol under the same depth of anesthesia, and the incidence of apnea and laryngospasm was higher than that of propofol The phenol group was lower than the sevoflurane group
.

If endotracheal intubation is performed, the application of muscle relaxants can reduce its incidence
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In comparative trials, topical infiltration anesthesia did not reduce its incidence, and application of lidocaine spray to the vocal cords increased the incidence of laryngospasm
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③Maintenance period: When the anesthesia is too shallow, laryngospasm is often caused by systemic noxious stimulation
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The incidence of laryngospasm was slightly higher with sevoflurane maintenance than with propofol intravenous infusion
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Desflurane maintenance significantly increased the incidence of respiratory adverse events during surgery
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④ Recovery period: awake state or deep anesthesia, which state extubation can reduce the incidence of laryngospasm is still under discussion.
Most studies suggest that extubation under deep anesthesia can reduce the incidence of laryngospasm, but other studies have shown that There is no difference
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One study showed that the incidence of adverse events of extubation and breathing under deep anesthesia was higher in patients with endotracheal intubation than in patients with laryngeal mask
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The incidence of adverse events in extubated breathing while awake was lower in intubated patients than in laryngeal mask patients
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In conclusion, it is relatively safe to remove the laryngeal mask under deep anesthesia and to remove the tracheal intubation while awake
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During recovery from anesthesia in children, an "artificial cough maneuver" (a rapid large lung expansion with 100% O2 prior to extubation of the endotracheal tube) can delay or prevent oxygen saturation relative to suction extubation after extubation.
Decreases in the first 5 minutes as strong airflow exhales secretions remaining in the throat into the mouth when the tracheal tube is in the trachea
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Usually, after the laryngospasm is relieved, most patients recover quickly and without sequelae, and a few may develop negative pressure pulmonary edema and require special treatment
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The typical cause of postoperative negative pressure pulmonary edema is upper airway obstruction, resulting in increased inspiratory power, progressive increase in negative pressure in the thoracic cavity, and increased pulmonary microvascular pressure, resulting in pulmonary edema
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80% of negative pressure pulmonary edema occurs after the upper airway obstruction is relieved, but some cases delay the occurrence of 4-6 hours after the obstruction is relieved, so it is considered that negative pressure pulmonary edema does not occur 4-6 hours after the occurrence of laryngospasm.
It didn't happen after that
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In neonates, the chest wall and lungs are highly compliant and disappear after the second year due to increased chest wall strength, which may be the reason why negative pressure pulmonary edema is less common in infants
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03 Treatment of sudden laryngospasm in peri-anesthesia period The treatment requirements for sudden laryngospasm in peri-anesthesia period generally include proper diagnosis, effective and timely treatment
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Many authors recommend airway control first, followed by medication if necessary
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(1) Airway control: In the past, the treatment standard was to remove irritants, lift the jaw, push the jaw, continuous mask continuous positive pressure ventilation (CPAP), to open the glottis, and reduce wheezing in children during anesthesia and spontaneous breathing.
sound, but continuous mask ventilation may cause gas and increase the risk of regurgitation of gastric contents
.

Data show that more children with laryngospasm can be improved with moderate intermittent positive pressure ventilation and mild chest and abdomen compression, and the treatment success rate is higher than that of the previous mask ventilation (73.
9% and 38.
4%), and the former has no one.
Flatulence occurred and the latter occurred in 86.
5% of patients
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Although hypoxia relaxes the vocal cords and makes CPAP easier to perform, it is not recommended because hypoxia increases the incidence of obstruction and pulmonary edema or even asystole
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Whether it is complete or partial laryngospasm, and whether laryngospasm can be relieved, venous access must be opened in time
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(2) Drugs ① Propofol: It can inhibit the laryngeal reflex and is widely used in the treatment of laryngospasm
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One study showed that 100% O2 inhalation and positive pressure ventilation after removal of the laryngeal mask but SpO2 dropped to 85%, given a small dose of propofol (0.
8mg/kg), 76.
9% of patients can be relieved, and the remaining patients need to be given chlorine.
Endotracheal intubation with succinylcholine
.

During tonsillectomy (with or without adenoidectomy), administration of a hyposomnia dose of propofol (0.
5 mg/kg) can reduce the incidence of laryngospasm during tracheal intubation
.

There are few data on propofol for laryngospasm in children younger than 3 years, and the efficacy of propofol in the setting of complete laryngospasm with bradycardia is questionable
.

Persistent complete laryngospasm requiring intravenous chlorosuccinylcholine
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Although subsleepy doses of propofol are successful in the treatment of pediatric laryngospasm, this dose is insufficient in infants, especially those younger than 1 year of age
.

②Muscle relaxants: When the first step in the treatment of laryngospasm fails, muscle relaxants need to be given
.

The most commonly used is chlorosuccinylcholine, others are rocuronium bromide, micuronium chloride, etc.
More recommended dosage of chlorosuccinylcholine is not less than 0.
5mg/kg, and the recommended dose for intramuscular injection is 1.
5-4mg/kg.
kg, the onset of action is slower than that of intravenous injection, but it can effectively relieve laryngospasm and the onset time is shorter than the time to reach the maximum muscle relaxation effect
.

Endotracheal intubation can be performed 45 seconds after administration
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For children with contraindications to chlorosuccinylcholine (burns, hyperkalemia, multiple fractures, pseudo-hyperglycemia), rocuronium bromide (0.
9-1.
2 mg/kg) can be used, and its effect can be suppressed by Sugammadex ( selective muscle relaxant antagonists) antagonists
.

Compared with placebo and neostigmine, Sugammadex rapidly (3 minutes) reversed any degree of neuromuscular blockade induced by rocuronium without any adverse effects
.

Prefer propofol or muscle relaxants depending on the severity of the laryngospasm (partial or complete), and closuccinylcholine is contraindicated in bradycardia
.

③Lidocaine: Since the 1970s, some scholars have studied the effect of lidocaine in the prevention and treatment of post-extubation laryngospasm.
has the opposite result
.

A randomized, double-blind, multicenter controlled prospective study showed that intravenous administration of 1.
5 mg/kg lidocaine 2 minutes before extubation in pediatric cleft palate surgery could reduce the occurrence of laryngospasm and cough (29.
9%, 18.
92%).
However, no other studies have confirmed this conclusion, and the prevention of laryngospasm by intravenous or local administration of lidocaine remains controversial
.

④ Other drugs: Other drugs for the prevention and treatment of laryngospasm include magnesium, doxapram, diazepam, and nitroglycerin
.

However, the number of patients in the group experiment was small, so no meaningful conclusions could be drawn
.

Severe bradycardia or even asystole may result from chlorosuccinylcholine injection in hypoxic patients, so atropine is required before intravenous chlorosuccinylcholine for laryngospasm
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04Thinking about sudden laryngospasm during peri-anesthesia (1) The management process of sudden laryngospasm and prevention of laryngospasm during peri-anesthesia is shown in Figure 28-1
.

Figure 28-1 Management process of laryngospasm Prevention of laryngospasm is shown in Figure 28-2 (2) Resolution of sudden laryngospasm crisis during peri-anesthesia 1.
Adequate preoperative preparation (1) Knowledge of medical history: with or without chronic bronchi History of inflammation, preoperative acute upper respiratory tract infection, long-term smoking or smoking exposure, repeated persistent pharyngeal infection,
etc.

(2) Necessary physical examination: including auscultation of the lungs and examination of the pharynx
.

(3) Grasp the indications of elective anesthesia: For patients with acute upper respiratory tract infection and recent pulmonary infection, elective surgery should be postponed
.

(4) Rational application of preoperative anticholinergic drugs: preoperative anticholinergic drugs can reduce glandular secretion, which is important for children who use ketamine or inhalation anesthetics
.

2.
Appropriate depth of anesthesia Moderate depth of anesthesia is of great significance to prevent laryngospasm caused by surgical stress and stimulation.
Surgical operations under light anesthesia and excessive stress state will induce laryngospasm, which is the best time for extubation.
Laryngeal spasm is now buried hidden dangers
.

3.
Appropriate timing of extubation The timing of extubation depends on which airway management method is used, but for patients with high risk factors for laryngospasm, gentle suction should be considered under deep anesthesia.
Under the condition that the tidal volume and respiratory rate can meet the physiological needs, the tracheal intubation is pulled out, and the positive pressure ventilation with a closed mask is used for transition
.

4.
Timely diagnosis of laryngospasm In patients with high risk factors of laryngospasm, if dyspnea and a sharp drop in blood oxygen saturation occur after extubation, one must be alert to the occurrence of laryngospasm, and a quick and accurate diagnosis can save the patient's life
.

5.
Correct treatment According to the standard treatment process of laryngospasm, most patients can recover quickly without any sequelae
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(3) Handling of disputes between doctors and patients and self-protection of doctors 1.
Sufficient and detailed preoperative conversation is essential.
Laryngeal spasm is a kind of emergency, and the course of the disease progresses very quickly.
If it is not handled in time, it may cause serious complications in patients.
Laryngeal spasm usually occurs during the operation and during the period of anesthesia and extubation after the operation.
It is an emergency situation that has no important relationship with the disease itself.
Therefore, the family members are often emotional and unacceptable after the occurrence of laryngeal spasm and death.
Therefore, it is very important to talk to high-risk groups of laryngospasm before surgery.
It is necessary to emphasize the possibility and serious harm of laryngospasm, so that patients and their families can fully understand and prepare psychologically
.

2.
Try to minimize the harm when medical disputes occur , it is still necessary to try our best to carry out further treatment and treatment to help the patient recover better
.

5.
Typical case sharing of sudden laryngospasm during peri-anesthesia period Case 1, the patient, female, 4 years old, weighing 19kg, was admitted to the hospital due to the chief complaint of "metastatic right lower abdominal pain for 8 hours", the diagnosis was: acute appendicitis, no special medical history.
, No upper respiratory tract infection before operation, ASA grade I, fasting for 6 hours, fasting for 4 hours, planned to perform appendectomy under general anesthesia without endotracheal intubation, intramuscular injection of ketamine 90mg, and hold the child for surgery after falling asleep After the skin incision, the child had body movement.
Then, 20 mg of ketamine and 2 mg of "Liyuexi" were intravenously injected.
After 5 minutes, the oxygen saturation of the child's finger pulse decreased, and the throat appeared.
Phlegm sound, obvious three concave signs during inhalation, cyanosis of the lips, pulse oxygen saturation dropped to 30%, heart rate dropped to 35 beats/min, immediate positive pressure ventilation with closed mask, but no thoracic ups and downs, diagnosis Laryngeal spasm occurred, immediately intravenous injection of propofol 50mg, succinylcholine 20mg, epinephrine 0.
1mg, tracheal intubation, positive airway pressure ventilation, finger pulse oxygen saturation gradually rose, heart rate increased, 2 hours after surgery , The child was awake, and the oropharyngeal secretions were successfully extubated after inhalation, and the postoperative recovery was good
.

Case 2, the patient, male, 42 years old, 70kg, has a long history of smoking, no acute upper respiratory tract infection before surgery, and underwent laparoscopic cholecystectomy under general anesthesia due to "cholecystitis"
.

Induction: "Liyuexi" 2mg, sufentanil 20ug, vecuronium 6mg, etomidate 12mg, the tracheal intubation was successful, and the airway pressure increased 30 minutes after the operation.
deal with
.

Sputum suction at the end of the operation found that the sputum was abundant and thin
.

10 minutes after the operation, the patient's muscle strength recovered, the tidal volume was 250-300ml, and the frequency was 12 times/min
.

So the tracheal tube was pulled out after suctioning the phlegm
.

After extubation, the patient had breathing action but no effective ventilation, lost consciousness, and the oxygen saturation of the fingers dropped sharply, followed by cyanosis, and SpO2 dropped from 99% to 50%.
Phenol 200mg intravenously
.

Ventilation improved, and the pulse oxygen saturation began to rise.
After 5 minutes, the above symptoms did not improve significantly, and the patient gradually became awake
.

About 20 minutes later, the patient was conscious, his respiratory function recovered, he could cooperate with the commanded movements, and there was no obvious manifestation of dyspnea
.

After 30 minutes of observation, the patient was returned to the ward
.

There is no special follow-up
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Notes/Hangbo Typesetting/Dingdang Wanzima "Qingming" (Tang Dynasty) Du Mu's Qingming season is rainy, and pedestrians on the road want to break their souls
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Where is the restaurant? The shepherd boy pointed to Xinghua Village
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