Laryngospasm and noncardiogenic pulmonary edema

Physiology Of Drowning: A Review

Drowning physiology relates to two different events: immersion (upper airway above water) and submersion (upper airway under water). Immersion involves integrated cardiorespiratory responses to skin and deep body temperature, including cold shock, physical incapacitation, and hypovolemia, as precursors of collapse and submersion. The physiology of submersion includes fear of drowning, diving response, autonomic conflict, upper airway reflexes, water aspiration and swallowing, emesis, and electrolyte disorders. Submersion outcome is determined by cardiac, pulmonary, and neurological injury. Knowledge of drowning physiology is scarce. Better understanding may identify methods to improve survival, particularly related to hot-water immersion, cold shock, cold-induced physical incapacitation, and fear of drowning.

Laryngospasm, central and obstructive apnea during seizures: Defining pathophysiology for sudden death in a rat model

Seizure spread into the autonomic nervous system can result in life-threatening cardiovascular and respiratory dysfunction. Here we report on a less-studied consequence of such autonomic derangements-the possibility of laryngospasm and upper-airway occlusion. We used parenteral kainic acid to induce recurring seizures in urethane-anesthetized Sprague Dawley rats. EEG recordings and combinations of cardiopulmonary monitoring, including video laryngoscopy, were performed during multi-unit recordings of recurrent laryngeal nerve (RLN) activity or head-out plethysmography with or without endotracheal intubation. Controlled occlusions of a tracheal tube were used to study the kinetics of cardiac and respiratory changes after sudden obstruction. Seizure activity caused significant firing increases in the RLN that were associated with abnormal, high-frequency movements of the vocal folds. Partial airway obstruction from laryngospasm was evident in plethysmograms and was prevented by intubation. Complete glottic closure (confirmed by laryngoscopy) occurred in a subset of non-intubated animals in association with the largest increases in RLN activity, and cessation of airflow was followed in all obstructed animals within tens of seconds by ST-segment elevation, bradycardia, and death. Periods of central apnea occurred in both intubated and non-intubated rats during seizures for periods up to 33s and were associated with modestly increased RLN activity, minimal cardiac derangements, and an open airway on laryngoscopy. In controlled complete airway occlusions, respiratory effort to inspire progressively increased, then ceased, usually in less than 1min. Respiratory arrest was associated with left ventricular dilatation and eventual asystole, an elevation of systemic blood pressure, and complete glottic closure. Severe laryngospasm contributed to the seizure- and hypoxemia-induced conditions that resulted in sudden death in our rat model, and we suggest that this mechanism could contribute to sudden death in epilepsy.

Black, white, and shades of gray: common abnormalities in chest radiographs

Chest radiographs remain one of the oldest, noninvasive methods for identifying chest diseases. This tool is relatively inexpensive, low risk, and important for the advanced practice nurse to use in making an initial differential diagnosis. Timely intervention depends on the advanced practice nurse's ability to recognize the radiographic abnormalities commonly associated with acute pulmonary disease. When linked with the history, presenting signs and symptoms, and a thorough physical assessment, the chest radiograph is key to appropriate diagnosis and management. This article reviews the basic radiographic lung densities, describes a systematic approach to ensure thorough chest radiographic interpretation, and presents characteristic chest radiographs found in the acute care setting. Selected examples of diffuse lung diseases, localized alveolar opacities, pleural effusions, and hyperlucency of the lungs will also be presented.

Postlaryngospasm pulmonary edema in adults

Laryngospasm is a potential serious complication of intubation. Pulmonary edema can develop after laryngospasm and can affect any patient who has been intubated. Postlaryngospasm pulmonary edema is potentially life threatening and can result in reintubation, mechanical ventilation, admission to an intensive care unit, and a prolonged hospitalization for the patient. Perioperative nurses play a significant role in the prompt detection, diagnosis, and treatment of this syndrome.