Laryngospasm and Negative Pressure Pulmonary Edema Management
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Learn about the recognition, signs, management, and prevention of laryngospasm and negative pressure pulmonary edema. Understand potential risks, differential diagnosis, and treatment options for these critical airway conditions.
Laryngospasm and Negative Pressure Pulmonary Edema Management
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Presentation Transcript
Laryngospasm and Negative Pressure Pulmonary Edema พญ.สุดารัตน์ ศุภกิจเจริญ หน่วยงานวิสัญญี โรงพยาบาลกำแพงเพชร
Laryngospasm is a form of airway obstruction. • Laryngospasm is usually easily detected and managed, but may present atypically and/or be precipitated by factors which are not immediately recognized. • If poorly managed, it has the potential to cause morbidity and mortality such as severe hypoxaemia, pulmonary aspiration, and post-obstructive pulmonary edema.
SIGNS • Inspiratory stridor/airway obstruction • Increased inspiratory efforts/tracheal tug • Paradoxical chest/abdominal movements • Desaturation • Bradycardia esp.in children • Central cyanosis
THINK OF • Airway irritation and/or obstruction • Blood/secretions in the airway • Regurgitation and aspiration • Excessive stimulation/“light” anaesthesia
MANAGEMENT Recognise Laryngospasm Apply CPAP c 100% O2 c airway maneuver Assess O2 entry Bag movement No Some Complete laryngospasm Partial laryngospasm
Complete laryngospasm Partial laryngospasm Consider specialized Maneuver to convert to partial laryngospasm Eliminate stimulus ex.secretion Deepen anesthesia c volatile or porpofol not improvement Reassess O2 entry No iv assess iv assess Improvement suxa 1-2 mg/kg iv +/- atropine 0.02mg/kg iv suxa 3-4 mg/kg im +/- atroine 0.02 mg/kg im CPAP ventilate c 100%O2 Attempt intubation as appropriate Improvement Stabilise and resume anesthesia +/- NG tube Not improved CPR + ACLS as indicated
Specialised maneuver • Pressure in laryngospasm notch • Pull mandible forward = forcible jaw thrust
Mechanism of Edema Formation • Two theories on the edema fluid formation • One of the theory suggests significant fluid shifts due to changes in intrathoracic pressure and hydrostatic transpulmonary gradient due to increased blood flow in pulmonary vessel. • The second proposed mechanism involves the disruption of the alveolar epithelial and pulmonary microvascular membranes from severe mechanical stress which leads to increased pulmonary capillary permeability and protein-rich pulmonary edema.
Negative Pressure Pulmonary Edema • Inspiratory efforts against a closed glottis (modified Mueller maneuver) may result in pleural pressures (> - 100 cm H2O) • Hypoxic pulmonary vasoconstriction • These changes result in: • Increased transmural pressure • Fluid filtration into the lung • Development of pulmonary edema and capillary failure.
Mechanism of Negative Pressure Pulmonary Edema 10 Pulmonary edema remains An upper airway obstruction occurs 1 9 2 The patient continues trying to inhale against the obstruction Airway obstruction is relieved 8 3 Fluid from the interstitial space floods into the alveoli A high degree of negative intra-thoracic pressure develops 7 4 A disruption in the alveolar membrane junction occurs Venous return to the heart increases 6 5 Pressure in the pulmonary capillary bed increases Cardiac output decreases
Normal Respiration -1cm H2O +1cm H2O
Normal Pressure - Oncotic Pressure (25mmHg) - Osmotic Pressure (15mmHg)
Airway Obstruction -1cm H2O
Risk assessment • Laryngospasm • Obesity, OSA • Young male athlets • Epiglotitis • Croup • Partial trachial obstruction by FB • Upper airway pathology ex .laryngomalacia, vocal cord paralysis • Obstructed ETT or LMA • Difficult intubation, nasal, oral or pharyngeal • Surgical site ex. Oropharynx,neck,urogenital • Extubation during light planes of anesthesia • Secretions falling on the vocal cords.
Signs and Symptoms • Frothy pink pulmonary secretions : Hallmark sign • Tachycardia,hypertension • Diaphoresis • Auscultation : Rales,Occasionally wheezing • Hypoxemia on pulse oximetry or ABG • Bilateral, alveolar infiltrates on chest x-ray
Differential diagnosis • ARDS • Intravascular volume excess • Cardiac abnormalities • Pulmonary emboli
Treatment • Early diagnosis • Reestablishment of the airway • Adequate oxygenation • Application of positive airway pressure • Via face mask or LMA • Endotracheal intubation with vent support • Although NPPE does not result from fluid overload, most authors recommend gentle diuresis using low-dose furosemide(1mg/kg).
Prevention • Early recognition • Avoid potential obstruction • Ensure adequate depth of anesthesia during use of facemask or LMA • Consider the use of Bite block to ensure patency of artificial airway during emergence from anesthesia • Perform trachial extubation in fully awake Pt.