Roux-en-Y Gastric Bypass (RYGB)

Anesthesia Implications

Position: Supine, Reverse Trendelenburg
Time: 1-2 hours (average)
Blood Loss: Low (10-50 ml)
Post-op Pain: Moderate (3-6)
Maintenance Paralytic: Yes

Anesthetic Approaches

  • GETT
The Anesthesia

Preoperative considerations – The patient will have been on bowel prep, so hydrating by IV is a great consideration. Many suggest opening the fluids completely (where not contraindicated). This will help to prevent large induction and intraoperative swings in hemodynamics.

Post-Induction – After induction, you’ll want to insert an Orogastric tube (OGT). The surgeon will tell you when to remove it. Put a bougie in patient’s mouth but do not advance it (the surgeon will tell you when they want you to advance it). Putting the bougie in the mouth after induction while the pt is still in the supine position is much easier than trying to do so when the pt is in a complete reverse trendelenburg position.

Trendelenburg – when the surgeon asks for reverse trendelenburg, turn the gas down a little and have phenylephrine or ephedrine nearby for drops in hemodynamics.

The Bougie – The bougie is used as a guide to create a new stomach pouch. The surgeon will suture around it. When surgeon tells you to advance the bougie, do so very slowly, being sure to watch the screen as you advance. Once the surgeon is done suturing around the bougie, they will ask you to remove it.

Post-suture check – After removing the bougie, the surgeon may have you insert another OGT and inject 60ml air through it. This is to ensure that the sutures are holding air (not leaking). Please note that the Post-suture check can also be done by inserting OG tube and connecting it to oxygen ( use oxygen extension tubing ), very slowly increasing the oxygen flow rate to 2L.

PSV ventilation – Obesity combined with a pneumoperitoneum may necessitate the use of to use PCV mode, even though pt will be in the reverse trendelenburg position.

PONV – Its very important to give a full run of antiemetics to ensure the patient does NOT have PONV postoperatively.

The Pathophysiology

The National Institutes of Health (NIH) recommends weight reduction surgery as the best alternative treatment for extreme obese patients who cannot lose weight by diet, exercise, and weight loss medications. Bariatric surgery is considered as the only effective long-term treatment for patients with BMI ≥ 40 or ≥ 35 with comorbidities.

Roux-en-Y is used to treat obesity by creating a small stomach pouch and rerouting the small intestine to bypass a large portion of the stomach.

During the surgery, a small stomach pouch is created, which limits the amount of food that can be consumed. This forces the patient to eat less, leading to reduced caloric intake. It also alters the flow of intestinal contents, leading to hormonal changes that affect appetite and metabolism. For instance, Ghrelin levels decrease, leading to reduced feelings of hunger and a decreased appetite.

The Surgery

A small stomach pouch is created and then the small intestine is divided. The surgeon connects the lower part to the new stomach pouch. The upper part of the small intestine is reattached to the lower part further downstream. The bypass results in decreased absorption of fats and carbohydrates and alters the flow of intestinal contents, leading to hormonal changes. These hormonal changes affect appetite and metabolism.