Oropharyngeal obstruction

Surgical removal of tissues may be necessary in some cases to alleviate symptoms, such as oropharyngeal obstruction (tonsillectomy) and progressive anemia and thrombocytopenia (splenectomy). 

Fig. 3.1. The mechanism of oropharyngeal obstruction in the supine position and the proper placement of the nasopharyngeal airway. Modified from [42], with permission. Copyright, American Heart Association...

Administer oxygen, usually 8-10 L/min however, lower concentrations may be appropriate for patients with chronic obstructive pulmonary disease. Maintain airway with oropharyngeal airway device. 

Maintenance of a patent airway. Use oropharyngeal or nasopharyngeal airway or endotracheal intubation if airway obstruction persists. 

Angioedema due to ACE inhibitors can manifest as recurrent episodes of facial swelling, which resolves on withdrawal, or as acute oropharyngeal edema and airways obstruction, which requires emergency treatment with an antihistamine and corticosteroids. It may be life-threatening (75) and may need tracheostomy (76). It is occasionally fatal (77). An unusual presentation with subglottic stenosis has also been reported (78). A variant form is angioedema of the intestine, which tends to occur within the first 24 8 hours of treatment (79,80). 

Monitoring for impending respiratory failure should include continued assessment of the adequacy of gag and cough reflexes, oxygen saturation, vital capacity and inspiratory force. Control of oropharyngeal secretions is essential. Patients at risk for hypoventilation usually develop airway obstruction or aspiration. In patients with botulism, deterioration of respiratory function is an indication for controlled, anticipatory ventilation. The proportion of patients requiring mechanical ventilation has varied from 20% in a food-borne outbreak to 60% in infant botulism. 

Ophthalmic effects due to direct ocular exposure to OPs include optic neuropathy, retinal degeneration, defective vertical smooth pursuit, myopia, and miosis. Respiratory effects, including muscarinic, nicotinic, and central effects, contribute to respiratory distress in acute and delayed OP toxicity, Muscarinic effects, such as bronchospasm and laiyngeal spasm, can lead to airway obstruction. Nicotinic effects can lead to weakness and paralysis of respiratory oropharyngeal tiiuscles. Central effects can lead to cessation of respiration. 

Dolovich et al. reported that oropharyngeal deposition was reduced from 65% of the emitted dose to 6.5% in a group of patients with varying degrees of airflow obstruction who inhaled aerosol from an MDI alone and an MDI used in combination with the small volume Aerochamber spacer, respectively. Total and regional lung deposition fractions were unaltered by the addition of the spacer (76). 

The parameter predicts the chance of impaction against an obstruction in the flow direction of the particle and can for instance be used to predict oropharyngeal deposition. Practically, instead of particle velocity sometimes the flow rate (4>) through an inhaler is used, but this does not enable comparative evaluations between different inhalers when the cross sections for airflow in the mouthpieces are different between the inhalers as this will result in different velocities. 

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