Aspiration management

short lecture note about aspiration management

1. Aspiration Management Prepared by: Wasihun Aragie NOV 2019

2. Definition ASPIRATION is defined as the inhalation of oropharyngeal or gastric contents into the larynx and lower respiratory tract. The nature of the aspirated material, volume of the aspirated material, and state of the host defenses are three important determinants of the extent and severity of aspiration pneumonia. Aspiration can occur at any time during the perioperative period .

3. Classification of aspiration Aspiration pneumonitis is defined as acute lung injury after the inhalation of regurgitated gastric contents. Aspiration pneumonitis ( Mendelson’s syndrome ) is a chemical injury caused by the inhalation of sterile gastric contents. This condition involves lung tissue damage as a result of aspiration of non-infective but very acidic gastric fluid .

4. Continued… The pH value of less than 2.5 as a threshold for chemical pneumonitis and the critical volume for severe pneumonitis is estimated at 0.8 mL/kg Most common causes are drug overdose, seizures, a massive cerebrovascular accident, or the use of anesthesia.

5. Continued… Aspiration pneumonia develops after the inhalation of colonized oropharyngeal material. Any condition that increases the volume or bacterial burden of oropharyngeal secretions in a person with impaired defense mechanisms may lead to aspiration pneumonia . Exogenous lipoid pneumonia (ELP) is a rare form of pneumonia caused by inhalation or aspiration of a fatty substance. ELP has been reported with inhalation or ingestion of petroleum jelly, mineral oils, “nasal drops,” and even intravenous injection of olive oil.

6. Mechanisms for Protection of Reflux and Aspiration in the Awake Patient Lower esophageal sphincter tone (LES): is the primary barrier to gastro-esophageal reflux Gastro-esophageal angle Upper esophageal sphincter Air way reflexes like: Sneezing Apnea Swallowing Laryngeal closure Coughing

7. Risk factors for regurgitation and pulmonary aspiration under general anesthesia Obesity Depressed level of consciousness History of gastritis/ulcer Bowel obstruction Pregnancy – greater than 12 weeks gestation Pain/stress Emergency surgery ASA IV-V

8. Continued… Ileus Trauma Concurrent opioid administration Symptomatic hiatal hernia Esophageal disorders/previous esophageal surgery Recent meal Diabetes mellitus

9. Signs of Pulmonary Aspiration Signs usually occur within 2 hours of the event Bronchospasm A drop in oxygen saturation of greater than 10% on room air A chest radiograph usually revealing atelectasis or an infiltrate Adult respiratory distress syndrome (ARDS) Hypoxia Increased inspiratory pressure Cyanosis Tachycardia Abnormal auscultation

10. Differential diagnosis Bronchospasm Laryngospasm Endotracheal tube obstruction Pulmonary edema ARDS Pulmonary embolism

11. Prevention Pharmacologic agents to decrease Gastric volume (either by decreasing production or by increasing emptying), Increase gastric pH, or Increase LES tone Metoclopramide Facilitates gastric emptying by causing gastric peristalsis and relaxation at the pylorus. It also increases LES tone Contraindications: bowl obstruction, Parkinson disease

12. Cimetidine or ranitidine Are competitive H 2 -blockers that will decrease basal gastric acid secretions Increase gastric P H . Sodium citrate is a non-particulate antacid that will increase gastric p H .

13. Continued… Omeprazole,Rabrazole,Lansoprazole are proton pump inhibitors that block H+-K+-adenosine triphosphates' activity at the secretory surface of the parietal cells in the stomach. These drugs decrease the volume and increase the pH of gastric secretions Glycopyrrolate, an anticholinergic, will increase gastric pH by inhibiting vagal mediated gastric acid production. Atropine, however, is ineffective.

14. Continued… Nasogastric tube placement Preoperative fasting Applying cricoid pressure during rapid sequence induction

15. Case A 23 years old male patient comes to DRH with compliant of two episode of vomiting, severe abdominal pain of 6 hours duration and diagnosis as acute appendicitis and scheduled for appendectomy. The anesthetist perform rapid assessment and found the following. History no previous anesthesia and surgery exposure. He has history of burn 5 years later at the neck area chest as well recently eat food. PE slight limitation of neck movement 2 fingerS admit and mallampati 3 the patient was anesthetized and intubated successfully with the second attempt using stylate and applying cricoid pressure in the middle of procedure saturation decrease from 95 to 80%. The anesthetist notice gastric content in the mouth area and bilateral crepitation on auscultation and suspect aspiration of gastric content into the lung.

16. Manage this patient following appropriate steps of aspiration management Required resource Emergency drug(adrenalin) Monitors (BP apparatus, stethoscope and pulse oxymetry ) GA equipment's(oxygen source, laryngoscope, ETT, IV anesthetic drugs, suction machine, suction tube, stylate , airway mask)

17. Management and treatment for aspiration If aspiration occurs, treatment is symptomatic. Call for help Place the patient to head down and lateral position Inspect the airway and remove particulate matter Remove the airway suction the pharynx Intubate and suction bronchial tree when the airway secured Ventilate with 100% O 2 Began PEEP as necessary to maintain oxygen saturation Administer B 2 agonist

18. Continued… Auscultate breath sounds periodically for wheezing, rhonchi, and rales Obtain initial chest radiograph Consult bronchoscopy Administer corticosteroids for edema and inflammation Place NG tube and empty stomach before extubation Perform smooth extubation Document the intraop period event Transfer to PACU/ICU Inform the recovery personnel about patient

19. Thank you