Laryngospasm & Bronchospasm PDF

BSc. Anesthesia & ICU Ameer Ahmed Al-hasnawi BASIC OF ANESTHESIA 2nd stage L.2 – Laryngospasm & bronchospasm Laryngospasm is a form of airway obstruction that is so common and different that most anesthesiologists consider it to b...

BSc. Anesthesia & ICU Ameer Ahmed Al-hasnawi BASIC OF ANESTHESIA 2nd stage L.2 – Laryngospasm & bronchospasm Laryngospasm is a form of airway obstruction that is so common and different that most anesthesiologists consider it to be a separate entity. the risk is greater in certain subgroups such as children with asthma or airway infections or those undergoing oesophagoscope or hypospadias repair, and adults undergoing anal surgery. In recognition of the fact that laryngospasm is a distinct entity, other forms of airway obstruction have been considered. While laryngospasm occurs relatively frequently and is nearly always easily recognized and handled, it has the potential to cause morbidity and mortality, especially if managed poorly. Laryngospasm occasionally presents atypically and may be precipitated by factors which are not immediately recognized, increasing the potential for patient harm and further complications such as pulmonary aspiration and post obstructive pulmonary oedema. This latter complication is especially significant as it may cause serious morbidity, and the patient may require intubation, ventilation and management in an intensive care setting. Risk factors include difficult intubation, nasal, oral or pharyngeal surgical site; and obesity with obstructive sleep apnea; however, it may occur unexpectedly in any patient. 1  BSc. Anesthesia & ICU Ameer Ahmed Al-hasnawi BASIC OF ANESTHESIA 2nd stage Tracheal tug Lung Sound Signs: *Inspiratory stridor/airway obstruction. *Increased inspiratory efforts/tracheal tug. Laryngospasm *Paradoxical chest/abdominal movements. *Desaturation, bradycardia, central cyanosis. Precipitating causes of laryngospasm: *Airway manipulation *Blood/secretions in the pharynx *Regurgitation/vomiting *Surgical stimulus *Moving patient *Irritant volatile agent *Failure of anesthetic delivery system *Unable to determine Management: *Cease stimulation/surgery *100% Oxygen *Try gentle chin lift/jaw thrust *Request immediate assistance *Deepen anesthesia with an IV agent *Visualize and clear the pharynx/airway 2  BSc. Anesthesia & ICU Ameer Ahmed Al-hasnawi BASIC OF ANESTHESIA 2nd stage *Suspect aspiration *Suspect airway obstruction *Try mask CPAP/IPPV, if this is unsuccessful, give suxamethonium unless contraindicated, give atropine unless contraindicated. Again, try mask CPAP/IPPV Intubate and ventilate Notes 1- About 77% of cases were clinically obvious, 14% presented as airway obstruction, 5% as regurgitation, 4% as desaturation. 2- The cricothyroid muscle is the only tensor of the vocal cords. Gentle stretching of this muscle may overcome moderate laryngospasm. In applying jaw thrust, gentle pressure should be exerted on the angle of the mandible, and not on soft tissues. 3- Try 20% of the induction dose; this may be all that is needed 4- Suxamethonium: Delay in relieving severe laryngospasm was associated with postobstructive pulmonary oedema and were managed with suxamethonium without intubation. 0.5mg/kg IV to relieve laryngospasm 1.0–1.5mg/kg IV for intubation. 4.0mg/kg IM for intubation (if no IV access). 5- Atropine: 0.01mg/kg. as bradycardia may occur 3  BSc. Anesthesia & ICU Ameer Ahmed Al-hasnawi BASIC OF ANESTHESIA 2nd stage 4  BSc. Anesthesia & ICU Ameer Ahmed Al-hasnawi BASIC OF ANESTHESIA 2nd stage Bronchospasm usually manifests during anesthesia as an expiratory wheeze, prolonged expiration and/or increased inflation pressures during intermittent positive pressure ventilation (IPPV). Wheeze may be audible either with or without auscultation, but can only be present if there is gas flow in the patient’s 5  BSc. Anesthesia & ICU Ameer Ahmed Al-hasnawi BASIC OF ANESTHESIA 2nd stage airways. Thus, in cases of severe bronchospasm, the chest may be silent on auscultation and the diagnosis may rest on correct assessment of increased inflation pressures. Other signs include; low oxygen saturation, change in capnogram, hypoventilation and hypotension. Causes: 1- During induction of anesthesia: Bronchospasm *Bronchospasm due to airway irritation *Anaphylaxis *Misplacement of endotracheal tube *Aspiration of gastric contents *Pulmonary oedema (following failed intubation) *Unknown, possibly allergy 2- During maintenance of anesthesia: *Anaphylaxis (or severe allergy) *Endotracheal tube or ventilator problem *Aspiration, laryngeal mask or mask anesthesia 3- During emergence or recovery phase of anesthesia: *Pulmonary oedema *Anaphylaxis/allergy *Accidental extubating *Extubation spasm *Aspiration *Unilateral bronchospasm and pulmonary oedema (cause not determined) *No defined cause Management: Once the signs of bronchospasm appear, think of: *Anaphylaxis. Allergy to drugs, IV fluid and latex. *Airway manipulation, irritation, secretions and soiling. *Esophageal or endobronchial intubation. 6  BSc. Anesthesia & ICU Ameer Ahmed Al-hasnawi BASIC OF ANESTHESIA 2nd stage *Pneumothorax *Inadequate anesthetic depth of failure of anesthetic delivery system. Emergency management *100% oxygen *Stop stimulation and surgery *Deepen anesthesia *If intubated exclude esophageal or endobronchial position *If mask or laryngeal mask consider laryngospasm, regurgitation, vomit and aspiration *Give adrenaline or salbutamol. *If you cannot ventilate via endotracheal tube, consider: Misplaced, kinked, blocked tube or circuit, pneumothorax, aspiration, anaphylaxis and pulmonary oedema. *Consider possible obstruction distal to the tube: Try to push a small tube past it or push the obstruction down one bronchus and ventilate the other lung *Magnesium sulphate3 (1.2–2 g i.e.) can be helpful in difficult cases; it is cheap, available, and also can suppress tachyarrhythmia Further management: *Bronchodilators, Chest x-ray and admission to the ICU. *Recommended dosage of drugs: - Salbutamol 0.5% 1ml (5mg) solution nebulized for adult or aerosol puffer, 2 puffs (0.1mg/puff) Adrenaline 0.001 mg/kg bolus (0.01 ml/kg of 1:10 000 solution). Repeat bolus, or begin infusion 0.00015mg/kg/min. 7