Laryngospasm under anaesthesia: causes, risks and treatment

Anyone planning cosmetic surgery will want to know what the actual risks associated with anaesthesia are and how well the team is prepared to deal with them. Laryngospasm under anaesthesia is one of the rare but serious complications that can occur during any surgical procedure carried out under general anaesthesia. Among the Risks associated with cosmetic procedures and ways to protect against them 4beauty provides comprehensive information.

Pathophysiology: How does vocal cord spasm develop?

Laryngospasm, also known as a glottal spasm, is a reflexive protective mechanism of the body. Under normal circumstances, this reflex prevents foreign matter from entering the lower airways and the lungs. The supraglottic structures – that is, the mucous membranes and nerve endings above the glottis – are extremely sensitive and react to even the slightest stimuli with a spasmodic contraction of the laryngeal muscles.

Under anaesthesia, this protective mechanism gets out of control. The body triggers the spasm even though there is no real risk of aspiration; this is why it is referred to as an „excessive“ reflex. The vocal cords close completely, making ventilation impossible, and the oxygen level in the blood drops to dangerous levels within a matter of seconds.

The excitation phase: the neurophysiological weak point

The excitation stage refers to the transitional phase between wakefulness and deep anaesthesia, and vice versa during recovery. During this phase, protective reflexes such as the laryngospasm reflex are particularly active, whilst cortical control over them is still absent or has not yet been restored. If even a single drop of saliva or blood comes into contact with the sensitive mucous membranes during this critical window, it can trigger the spasm.

According to a review article in the specialist journal Anaesthesiology (Bhananker et al.) state that the neural basis lies in the superior laryngeal nerve, whose afferent fibres respond to minimal stimuli with a maximum efferent response to the adductors of the glottis. This mechanism explains why even a well-positioned airway does not provide complete protection as long as the depth of anaesthesia is insufficient.

When does laryngospasm occur under anaesthesia?

Laryngospasm typically occurs in three distinct phases. Understanding these phases helps anaesthetists to monitor patients particularly closely at critical moments.

The most common time is during extubation, i.e. the removal of the endotracheal tube at the end of the operation. The patient is just emerging from deep anaesthesia, protective reflexes are returning, and at the same time, saliva or blood from the surgical site may irritate the larynx. The DGAI guideline on airway complications describes this transition as the highest-risk phase of general anaesthesia.

When inducing anaesthesia, particularly during inhalational induction with sevoflurane, the excitation phase is a known risk period. If a child or adult enters a state of anaesthesia that is too shallow before the protective reflexes have completely ceased, the mere insertion of a laryngeal mask may trigger a spasm.

Laryngospasm under a laryngeal mask: an underestimated risk

The laryngeal mask (LAMA) is positioned supraglottically, i.e. above the glottis, rather than in the trachea like an endotracheal tube. This makes it gentler for many patients, but increases the risk of laryngospasm if the depth of anaesthesia is insufficient or if secretions enter the contact area. Clinical experience in anaesthesiology shows that, particularly during short cosmetic procedures – which are frequently carried out using a laryngeal mask – care must be taken to ensure a sufficient depth of anaesthesia during insertion and removal.

Risk factors: Who is particularly at risk?

The risk factors for laryngospasm can be divided into three categories: patient-related, procedure-related and anaesthesia-related factors. None of these factors is decisive on its own; it is often a combination of several unfavourable conditions.

Why are children more frequently affected?

Children have a narrower larynx, more sensitive mucous membranes and a more pronounced laryngospasm reflex than adults. According to data from paediatric anaesthesiology, laryngospasm occurs in children under 3 years of age at a rate of up to 10 %, compared with approximately 1–2 % in adults. Furthermore, children have lower oxygen reserves: an untreated spasm leads to dangerous hypoxaemia more quickly in them than in adults. For this reason, paediatric anaesthesia is regarded as a specialist field with particularly stringent safety protocols.

Cosmetic surgery such as otoplasty (ear correction) is also carried out on young people. Anyone planning such procedures for children or teenagers should discuss this risk factor with the anaesthetist. For cosmetic procedures involving anaesthetic risks, the Aftercare insurance from 4beauty financial protection against unforeseen follow-up treatment.

Symptoms and diagnosis: How laryngospasm manifests itself

The clinical presentation of laryngospasm is easily recognisable to experienced anaesthetists, but varies significantly depending on its severity. A partial laryngospasm, in which the glottis is not completely closed, manifests as a high-pitched inspiratory stridor. The patient is visibly struggling to breathe, and the accessory respiratory muscles are working at full capacity.

Paradoxically, complete laryngospasm is quieter: as no air is flowing through the closed glottis, no breathing sounds can be heard. The anaesthetist notices a sharp increase in ventilatory resistance, whilst oxygen saturation drops rapidly on the monitor. If the condition remains untreated, it is followed by bradycardia (a slowed heart rate), cardiac arrhythmias and, in the worst case, cardiac arrest.

Distinguishing it from bronchospasm

Laryngospasm and bronchospasm are sometimes confused because both make breathing difficult. The key difference is that, in laryngospasm, the obstruction occurs in the upper airway, at the glottis. In bronchospasm, the deeper-lying bronchi of the lungs constrict. Clinically, bronchospasm is characterised by a distinctive expiratory wheeze, whilst laryngospasm produces an inspiratory wheeze in cases of partial obstruction and no respiratory sounds at all in cases of complete obstruction. Both conditions are medical emergencies, but the treatment differs fundamentally.

Treatment: Step-by-step emergency management

Emergency management of laryngospasm during anaesthesia follows a clearly structured algorithm. Each step builds on the previous one; time is of the essence, as the patient’s oxygen reserves are depleted within minutes.

1. Remove the irritant and suction out the secretion The triggering factor – saliva, blood or stomach contents – is immediately removed from the throat. At the same time, the patient is given 100 % oxygen via a face mask.
2. Esmarch handle and CPAP The Esmarch manoeuvre, which involves a forceful thrust of the lower jaw forwards and upwards, stretches the supraglottic soft tissues and can mechanically relieve the spasm. Continuous positive airway pressure (CPAP) also helps to counteract the contraction of the glottis.
3. Deepening anaesthesia with propofol A subhypnotic dose of propofol (0.25–0.5 mg/kg i.v.) reduces the reflex sensitivity of the laryngeal muscles. This measure is sufficient in approximately 70–80 per cent of cases of mild to moderate spasms.
4. Succinylcholine for severe spasms Succinylcholine is a depolarising muscle relaxant that takes effect within 30–60 seconds and causes complete relaxation of the laryngeal muscles. The standard dose for adults is 1–1.5 mg/kg intravenously. If no venous access is available, succinylcholine may also be administered intramuscularly (4 mg/kg), with a correspondingly longer onset of action.
5. Intubation and post-operative intensive care Once relaxation has been successfully achieved, endotracheal intubation is performed. Patients with severe laryngospasm remain in the intensive care unit for monitoring, as post-obstructive pulmonary oedema may occur as a complication.

Possible complications following laryngospasm

Even a successfully treated laryngospasm can have lasting effects. Post-obstructive pulmonary oedema (also known as „negative pressure pulmonary oedema“) occurs when the patient breathes against the closed glottis, thereby creating a massive negative pressure in the lungs. Fluid leaks from the pulmonary vessels into the surrounding tissue. Clinically, this manifests as shortness of breath, frothy sputum and a fall in oxygen saturation following treatment of the spasm.

Prolonged, untreated laryngospasm can lead to cardiac arrhythmias or even cardiac arrest. The good news is that with prompt treatment in accordance with clinical guidelines, patients recover without any long-term consequences. However, it is not uncommon for patients to require an extended hospital stay following surgery, and it is precisely these additional costs that are of particular relevance to patients undergoing cosmetic surgery.

Prevention: How anaesthetists prevent laryngospasm

Prevention begins before the operation. According to the recommendations of the European Society of Anaesthesiology and Intensive Care (ESAIC), elective procedures – which include most cosmetic surgeries – should be postponed by at least two weeks in patients with active upper respiratory tract infections. The risk of laryngospasm is significantly increased during this period.

Anaesthetic procedures

The most important preventative measure is to ensure a sufficient depth of anaesthesia at all critical stages: when inserting and removing the laryngeal mask, and during extubation. Propofol, when used as an intravenous induction agent, is considered preferable to inhalational induction as it suppresses laryngeal reflexes more effectively.

There are two strategies available for extubation: „deep extubation“ (removal of the tube whilst the patient is still under deep anaesthesia, before reflexes have returned) and „awake extubation“ (removal only once the patient is fully conscious and protective reflexes are assured). Which strategy is safer depends on the individual patient and is determined by the anaesthetist prior to the operation.

Pharmacological prophylaxis

In high-risk patients, such as children with hyperreactive airways or patients undergoing elective rhinoplasty, prophylactic administration of lidocaine (1–2 mg/kg intravenously) shortly before extubation may reduce reflex sensitivity. Magnesium sulphate is also used prophylactically in some hospitals, as it modulates neuromuscular transmission. Neither substance is standard practice; instead, they are used on a case-by-case basis following a risk assessment.

Measure	Date and time	Objective
Allow a respiratory infection to run its course	Pre-operative (at least a 2-week break)	Reducing hyperreactivity
Propofol induction instead of inhalation	Induction of anaesthesia	Suppress laryngeal reflexes
Adequate depth of anaesthesia	Critical phases (induction/delivery)	Preventing reflex activation
Intravenous lidocaine (1–2 mg/kg)	Shortly before extubation	Reduce reflex sensitivity
Deep or conscious extubation	End of the operation	Bypass the excitation stage

Laryngospasm and the financial consequences for cosmetic surgery patients

Laryngospasm almost always prolongs the hospital stay. Even if the spasm is treated within seconds, the patient remains under close observation for at least several hours, often overnight. If post-obstructive pulmonary oedema develops, intensive care is required: oxygen therapy, and in severe cases, mechanical ventilation and diuretic therapy.

For patients who pay for cosmetic surgery out of their own pocket, this presents a specific financial risk. Statutory health insurance does not cover any follow-up costs associated with cosmetic procedures, neither an extended hospital stay nor medically necessary follow-up treatment resulting from complications arising from anaesthesia.

Follow-on costs insurance closes precisely this gap: it covers medically necessary treatment arising as a result of the insured procedure, regardless of whether the complication occurs during anaesthesia or during the operation itself. The table below shows which procedures are insurable with 4beauty: Overview of the treatments covered. The 4beauty team can answer any specific questions about cover at Contact.

Frequently asked questions about laryngospasm under anaesthesia