CHAPTER 39 Aspiration Malcolm Packer, MD 1 What is aspiration and what differentiates aspiration pneumonitis from aspiration pneumonia? Aspiration is the passage of material from the pharynx into the trachea. Aspirated material can originate from the stomach, esophagus, mouth, or nose. The materials involved can be particulate such as food or a foreign body or fluid such as blood, saliva, or gastrointestinal contents. Aspiration of gastric contents may occur by vomiting, which is an active propulsion from the stomach up the esophagus, or by regurgitation, which is the passive flow of material along the same path. Aspiration pneumonitis describes the initial imflammatory response after aspiration, and aspiration pneumonia describes the consolidation along with the imflammation. 2 How often does aspiration occur and what is the morbidity and mortality rate? The results of several different retrospective and prospective surveys of adult anesthetics place the incidence at one to seven cases of significant aspiration per 10,000 anesthetics. Studies of children’s anesthetics demonstrate about twice that occurrence. The average hospital stay is 21 days, much of which is in intensive care. Complications range from bronchospasm and pneumonia to acute respiratory distress syndrome, lung abscess, and empyema. The average mortality rate is 5%. 3 What are risk factors for aspiration? Extremes of age Emergency cases Type of surgery (most common in cases of esophageal, upper abdominal, or emergency laparotomy surgery) Recent meal (Preoperative fasting guidelines for elective surgery are discussed in Chapter 17.) Delayed gastric emptying and/or decreased lower esophageal sphincter tone (diabetes, gastric outlet obstruction, hiatal hernia Medications (e.g., narcotics, anticholinergics) Trauma Pregnancy Pain and stress Depressed level of consciousness Morbid obesity (including after bariatric surgery and the resulting weight loss) Difficult airway Neuromuscular disease (impaired ability to protect the trachea) Esophageal disease (e.g., scleroderma, achalasia, diverticulum, Zenker’s diverticulum) 4 What precautions before anesthetic induction are required to prevent aspiration or mollify its sequelae? The main precaution is to recognize which patients are at risk. Patients should have an adequate fasting period to improve the chances of an empty stomach. Gastrokinetic medications such as metoclopramide have been thought to be of benefit because they enhance gastric emptying, but no good data support this belief. It is helpful to increase gastric pH by either nonparticulate antacids such as sodium citrate or histamine-receptor (H2) antagonists, which decrease acid production. The market now includes several H2 Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: 76: Electroconvulsive Therapy 48: Alcohol and Substance Abuse 64: Pacemakers and Internal Cardioverter Defibrillators 41: Acute Respiratory Distress Syndrome (ARDS) 49: Diabetes Mellitus 60: Obstetric Analgesia and Anesthesia Tags: Anesthesia Secrets May 31, 2016 | Posted by admin in ANESTHESIA | Comments Off on 39: Aspiration Full access? Get Clinical Tree
CHAPTER 39 Aspiration Malcolm Packer, MD 1 What is aspiration and what differentiates aspiration pneumonitis from aspiration pneumonia? Aspiration is the passage of material from the pharynx into the trachea. Aspirated material can originate from the stomach, esophagus, mouth, or nose. The materials involved can be particulate such as food or a foreign body or fluid such as blood, saliva, or gastrointestinal contents. Aspiration of gastric contents may occur by vomiting, which is an active propulsion from the stomach up the esophagus, or by regurgitation, which is the passive flow of material along the same path. Aspiration pneumonitis describes the initial imflammatory response after aspiration, and aspiration pneumonia describes the consolidation along with the imflammation. 2 How often does aspiration occur and what is the morbidity and mortality rate? The results of several different retrospective and prospective surveys of adult anesthetics place the incidence at one to seven cases of significant aspiration per 10,000 anesthetics. Studies of children’s anesthetics demonstrate about twice that occurrence. The average hospital stay is 21 days, much of which is in intensive care. Complications range from bronchospasm and pneumonia to acute respiratory distress syndrome, lung abscess, and empyema. The average mortality rate is 5%. 3 What are risk factors for aspiration? Extremes of age Emergency cases Type of surgery (most common in cases of esophageal, upper abdominal, or emergency laparotomy surgery) Recent meal (Preoperative fasting guidelines for elective surgery are discussed in Chapter 17.) Delayed gastric emptying and/or decreased lower esophageal sphincter tone (diabetes, gastric outlet obstruction, hiatal hernia Medications (e.g., narcotics, anticholinergics) Trauma Pregnancy Pain and stress Depressed level of consciousness Morbid obesity (including after bariatric surgery and the resulting weight loss) Difficult airway Neuromuscular disease (impaired ability to protect the trachea) Esophageal disease (e.g., scleroderma, achalasia, diverticulum, Zenker’s diverticulum) 4 What precautions before anesthetic induction are required to prevent aspiration or mollify its sequelae? The main precaution is to recognize which patients are at risk. Patients should have an adequate fasting period to improve the chances of an empty stomach. Gastrokinetic medications such as metoclopramide have been thought to be of benefit because they enhance gastric emptying, but no good data support this belief. It is helpful to increase gastric pH by either nonparticulate antacids such as sodium citrate or histamine-receptor (H2) antagonists, which decrease acid production. The market now includes several H2 Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: 76: Electroconvulsive Therapy 48: Alcohol and Substance Abuse 64: Pacemakers and Internal Cardioverter Defibrillators 41: Acute Respiratory Distress Syndrome (ARDS) 49: Diabetes Mellitus 60: Obstetric Analgesia and Anesthesia Tags: Anesthesia Secrets May 31, 2016 | Posted by admin in ANESTHESIA | Comments Off on 39: Aspiration Full access? Get Clinical Tree
