Reflux of gastric contents into the esophagus is associated with symptoms.
The esophagus extends from C6 to LES.
The esophagus has three functional zones:
High intragastric pressure can lead to reflux into the esophagus and increased aspiration risk.
Optimal preoperative conditions have gastric volume <0.4 mL/kg and gastric pH >2.5, which is part of the reason for NPO and premeditations to minimize the risk of aspiration pneumonia. Normal gastric pH 1-3.5.
The urgency of surgery, airway problems, light anesthesia, lithotomy position, diabetes, pregnancy, and obesity lead to increased abdominal pressure.
Patients with reflux disease often have associated respiratory symptoms (laryngitis, recurrent pneumonia, progressive pulmonary fibrosis) along with heartburn and regurgitation.
Decrease LES pressure: thiopental, propofol, opioids, anticholinergics, and inhaled anesthetics.
Increase LES pressure: antiemetics, cholinergics, antacids, and succinylcholine.
Nondepolarizing muscle relaxants and H2-receptor antagonists do not affect LES pressure.
Zantac 150 mg po
H2 blocker - blocks histamine = decreased acid production in stomach = increased pH) Lasts 3 hrs
Reglan 10 mg po
Increases mobility
Alka-Seltzer Gold 2 tabs with 30 mL of water
The goal is to increase stomach PH to >2.5 before intubation to decrease the severity of aspiration pneumonia
Omeprazole (proton pump inhibitor) should be given the night before
Sodium citrate (non-particulate) should be given with prokinetic and only to morbidly obese, pregnant, or diabetic patients.
This combination elevates pH to >2.5 and ensures <25 mL of gastric contents
Neutralizes gastric acid. Note high sodium content of 1meq/ml) - dilute with water to prevent N/V
Elevate the head during intubation. Consider using cricoid pressure and performing RSI (controversial since Succinylcholine increases LES tone, and cricoid pressure decreases LES tone).
Insert NG tube post intubation to manage GI secretions. Consider antiemetic.
If possible, transport the patient to PACU on the side and have suction readily available.