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GI — Bowel Obstruction, Liver Resection, Carcinoid

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Specialty III · 10 min read

Full-stomach RSI + low-CVP liver technique + carcinoid octreotide pre-load — three GI surgery anesthetic clinics.

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Anticipate full-stomach risk in bowel obstruction.
Manage liver resection hemodynamics.
Plan for ERCP + colonoscopy MAC.
Recall pneumoperitoneum effects.

Bowel obstruction induction

KeyFull stomach physiology — high aspiration risk.

RSI principles strict

pre-O₂ ≥3 min
etomidate/propofol + sux 1.5 mg/kg or roc 1.2 mg/kg
no mask ventilation
intubate at peak block

Pre-op NG decompression reduces gastric volume — keep on suction.

Cricoid pressure controversial (DAS 2015 softened).

Head-up tilt + ramped position.

Adequate IV access.

Volume resuscitation pre-induction (often volume-depleted from third-spacing).

Rapid sequence induction (RSI): indications (full stomach, GERD, OB, bowel obstruction, trauma), classic steps - preoxygenation, induction agent (propofol/etomidate/ketamine), succinylcholine 1-1.5 mg/kg or rocuronium 1.2 mg/kg, cricoid pressure (debated), no mask vent.

Hepatic resection — low CVP technique

KeyTarget CVP <5 mmHg during liver transection — reduces hepatic venous bleeding (cava compresses hepatic veins easily when CVP low).

Achieve via

fluid restriction
reverse Trendelenburg
nitroglycerin infusion if needed
low tidal volume + low PEEP

Transition to liberal fluids post-resection (replace 3rd-space + maintain perfusion).

Lactate clearance + glucose monitoring intra-op.

Carcinoid syndrome

KeyTumor-secreted vasoactive substances (serotonin, histamine, bradykinin, prostaglandins) cause crisis on tumor manipulation.

Pre-op octreotide preload 300-500 mcg subcut night before + 50-200 mcg IV at induction + infusion.

Avoid histamine-releasing drugs (morphine, atracurium, succinylcholine).

Prepare for both hypotension + hypertension + bronchospasm.

ICU postop.

Octreotide rescue for breakthrough symptoms.

ERCP positioning + sedation

KeyEndoscopic retrograde cholangiopancreatography.

Prone or left lateral position.

Limited airway access (endoscope in mouth).

Often non-OR location.

MAC sedation adequate for routine (propofol-based, dex adjunct), GA for complex/prolonged.

Capnography mandatory.

Aspiration risk in prone position.

Convert to GA

difficult airway
OSA
full stomach
very long case

Esophagectomy + DLT

KeyMajor thoracoabdominal procedure.

One-lung ventilation via left DLT or bronchial blocker for thoracic phase.

Lateral position then prone for some approaches (minimally invasive Ivor Lewis).

Aggressive multimodal analgesia (thoracic epidural or paravertebral catheter).

Restrictive fluid management (anastomotic leak risk).

ICU postop for first 24-48 hr.

Post-thoracotomy pain management: thoracic epidural (gold standard), paravertebral block, intercostal blocks, erector spinae, serratus plane; multimodal with acetaminophen, NSAIDs, opioids. Adequate analgesia reduces atelectasis, pneumonia, chronic post-thoracotomy pain syndrome.

IBD + chronic steroids

KeyInflammatory bowel disease patients often on prolonged corticosteroids adrenal suppression.

STRESS STEROID COVERAGEhydrocortisone 50 mg IV at induction for moderate surgery, 100 mg q8h for major surgery × 24-48 hr.

Continue baseline immunosuppressants (biologic agents like infliximab, methotrexate) unless surgeon requests hold for wound healing — discuss with rheumatology/GI if uncertain.

Nutritional optimization pre-op (anemia correction, albumin).

Anastomotic leak risk elevated on steroids — surgical concern.

Stress-dose steroid protocol: minor surgery 25 mg hydrocortisone, moderate surgery 50-75 mg/day x 1-2 days, major surgery 100-150 mg/day x 2-3 days. Indicated for patients on chronic steroids (>5 mg pred for ≥3 weeks) within past year to prevent perioperative adrenal insufficiency.

Whipple + pancreatic surgery

KeyPancreaticoduodenectomy (Whipple): long (6-10 hr), large fluid shifts, significant blood loss, hemodynamic swings.

Anesthetic plan: arterial line + central line + Foley + epidural for postop analgesia (or ESP/QL block alternative).

Restrictive vs goal-directed fluid debate — modern trend favors goal-directed (SVV-guided, lower total volume) over liberal historic practice.

Post-op pancreatic fistula + delayed gastric emptying risks.

Pre-op carbohydrate drink + ERAS bundle reduces complications.

Patient often malnourished + diabetic at baseline.

ERAS pathway for C-section spans preop optimization, intraop multimodal analgesia and spinal anesthesia, and postop early oral intake and ambulation; key elements include standardized protocols and multidisciplinary teamwork to improve recovery.

Bariatric + sleeve gastrectomy considerations

Covered fully in bariatric anesthesia lecture; key GI-specific concerns: OG tube placement size matters (surgeon places bougie sized for sleeve resection — DON'T push past resistance, communicate with surgeon at the moment of OG insertion to avoid sleeve perforation).

Bilateral leak test at end of case via methylene blue or air injection through OG.

Multimodal opioid-sparing critical given OSA prevalence.

DVT prophylaxis aggressive given prothrombotic state of obesity.

PONV + ERAS bundles for GI surgery

KeyGI surgery has historically high PONV (related to bowel manipulation + opioid exposure + abdominal procedure).

Multimodal ANTI-EMETIC prophylaxis: ondansetron 4 mg + dexamethasone 4-8 mg + scopolamine patch (24 hr pre) ± aprepitant for very high risk.

PROPOFOL TIVA reduces PONV vs volatile.

ERAS BUNDLES for major colorectal: pre-op carbohydrate drink, multimodal analgesia (TAP block + IV lidocaine + ketamine + scheduled APAP/NSAID), opioid minimization, early ambulation, early enteral feeding, restricted IV fluids — reduces LOS by 1-2 days vs traditional care.

PONV multimodal prophylaxis using Apfel score (female, nonsmoker, h/o PONV/motion sickness, postop opioids); 0-1 factors low risk, ≥3 high risk. Combine agents from different classes: 5HT3 antagonist, dexamethasone, droperidol, scopolamine; TIVA with propofol if very high risk.

⚠ Common pitfalls

Bowel obstruction without RSI — distended gut + dependent emesis.
Liver resection with high CVP — hepatic congestion + worse bleeding.
ERCP without preventing pancreatitis — IV indomethacin reduces post-ERCP rates.
Forgetting pneumoperitoneum drops CO + raises ICP — relevant in glaucoma, neuro.

💎 Clinical pearls

Pringle maneuver (portal triad clamp) during liver resection — anticipate ↑afterload + ↓preload.
Low CVP (≤5) reduces hepatic venous backflow + bleeding — controversial vs Sevo-induced renal/oxygenation effects.
Bariatric ramped positioning + adequate pre-O2 + apneic O2 reduces hypoxemia during induction.
Steep Trendelenburg + pneumoperitoneum: ↑ICP, IOP, FRC ↓ — relative contraindications.

Recap

Pringle maneuver (portal triad clamp) during liver resection — anticipate ↑afterload + ↓preload.
Low CVP (≤5) reduces hepatic venous backflow + bleeding — controversial vs Sevo-induced renal/oxygenation effects.
Bariatric ramped positioning + adequate pre-O2 + apneic O2 reduces hypoxemia during induction.
Steep Trendelenburg + pneumoperitoneum: ↑ICP, IOP, FRC ↓ — relative contraindications.

Mark each section done to complete the module.