Eduovisual
Perioperative & Surgical Care
Bariatric surgery: pre-op evaluation and post-op complications
— Bariatric/metabolic surgery encompasses anatomic GI procedures designed to produce durable weight loss and remission of obesity-related comorbidities (T2DM, OSA, HTN, NAFLD, dyslipidemia, GERD, infertility).
— Most common US procedures: sleeve gastrectomy (SG, ~60%), Roux-en-Y gastric bypass (RYGB, ~20%), one-anastomosis gastric bypass (OAGB), biliopancreatic diversion with duodenal switch (BPD-DS), and adjustable gastric banding (now rare).
— BMI ≥35 kg/m² regardless of comorbidities (lowered from prior ≥40).
— BMI 30–34.9 with metabolic disease, particularly uncontrolled T2DM.
— Asian populations: thresholds shifted down by ~2.5 kg/m² (consider at BMI ≥27.5).
— Adolescents: BMI ≥120% of 95th percentile with comorbidity, or ≥140% regardless.
— Failed structured lifestyle/pharmacotherapy (GLP-1 RA, phentermine-topiramate) for ≥6 months.
— Worsening metabolic syndrome, progressive joint disease delaying arthroplasty, NASH with fibrosis, refractory OSA.
— Persistent obesity-related infertility before ART.
— Active substance use disorder, untreated severe psychiatric illness, active eating disorder (bulimia nervosa), pregnancy/lactation, inability to comply with lifelong follow-up/supplementation, prohibitive cardiopulmonary risk.
— RYGB and SG produce early, weight-loss-independent diabetes remission via altered GLP-1, PYY, ghrelin, and bile acid signaling — often within days.
Step 3 management: A 44-year-old with BMI 32, A1c 8.9% on metformin + semaglutide, OSA on CPAP — refer to a multidisciplinary bariatric program; do not wait for BMI to cross 35. Metabolic surgery is now a guideline-endorsed option at BMI 30–34.9 with uncontrolled diabetes, and referral itself is the correct next step rather than further drug titration alone.
— Establish duration of obesity, prior weight-loss attempts (commercial programs, pharmacotherapy trials, prior bariatric procedures), and weight trajectory in the last year.
— Quantify obesity-related comorbidities: T2DM (duration, insulin use, C-peptide), HTN, dyslipidemia, OSA (STOP-BANG, polysomnography), GERD, NAFLD/NASH, PCOS, degenerative joint disease, pseudotumor cerebri, venous stasis.
— Eating patterns: grazing, night eating, binge eating disorder (BED present in ~25% of candidates — not an absolute contraindication but must be treated).
— Alcohol use: critical baseline — RYGB markedly increases alcohol absorption and post-op AUD risk.
— Tobacco: must stop ≥6 weeks pre-op (marginal ulcer, anastomotic leak, wound complications).
— Adherence track record with chronic medications, clinic visits, supplements.
— History of trauma, depression, anxiety, suicidality (suicide risk rises post-bariatric surgery — screen carefully).
— Social support, transportation, food security, insurance coverage of supplements and follow-up.
— NSAIDs (must discontinue after RYGB — marginal ulcer risk), chronic opioids, anticoagulants, oral contraceptives (switch from oral to non-oral form post-RYGB due to malabsorption), teratogens.
— GLP-1 agonists: hold prior to surgery per ASA guidance (aspiration risk — typically 1 week for weekly agents).
— Early (<30 d): tachycardia, fever, abdominal/back/shoulder pain → leak until proven otherwise.
— Late: dysphagia, food intolerance, bilious vomiting (internal hernia), abdominal pain after meals (marginal ulcer, stricture), dumping symptoms, neuroglycopenia, neuropathy.
Board pearl: Persistent tachycardia >120 in the first post-op week after RYGB or SG is the single most sensitive sign of an anastomotic/staple-line leak — even before fever or peritonitis. Always image (CT with oral contrast or operative re-exploration) rather than attribute to pain or volume status.
— Accurate height, weight, BMI, waist circumference, neck circumference (OSA predictor).
— Skin: intertriginous candidiasis, panniculitis, acanthosis nigricans (insulin resistance), venous stasis ulcers, pannus mapping for surgical access.
— Cardiopulmonary: JVP, S3, peripheral edema (right heart strain from OSA/obesity hypoventilation), bibasilar crackles.
— Abdominal: prior surgical scars, hernias, hepatomegaly (NAFLD), striae.
— Airway: Mallampati score, thyromental distance, cervical mobility — anticipate difficult intubation.
— 6-minute walk test or stair climb — surrogate for METs; <4 METs = elevated perioperative cardiac risk.
— Joint range of motion (informs post-op mobility/VTE risk).
— HR >120, RR >22, SBP <90, oliguria, mental status change → presume leak, hemorrhage, or PE.
— Obese patients mask hemodynamic instability: relative tachycardia (delta from baseline >20) is more useful than absolute thresholds.
— Examine drain output: bilious, feculent, or rising lactate-containing fluid = leak.
— Abdominal exam in early post-op: shoulder tip pain (diaphragmatic irritation from leak), referred back/left flank pain after SG.
— Pallor + glossitis + neuropathy: B12/iron deficiency.
— Wernicke triad (ophthalmoplegia, ataxia, confusion) after persistent vomiting → thiamine deficiency.
— Hyperpigmented rash on extremities, perioral dermatitis: zinc deficiency.
— Postprandial diaphoresis, palpitations, confusion 1–3 h after eating: late dumping/hyperinsulinemic hypoglycemia.
Key distinction: Early dumping (15–30 min post-meal) is vasomotor — tachycardia, flushing, cramping, diarrhea from rapid osmotic load. Late dumping (1–3 h) is reactive hypoglycemia from exaggerated GLP-1/insulin surge. Treatment differs: early → dietary modification; late → low-glycemic diet ± acarbose or somatostatin analog.
— CBC, CMP, lipid panel, HbA1c, TSH, lipase.
— Nutritional baseline: ferritin, iron studies, B12, folate, 25-OH vitamin D, PTH, calcium, magnesium, phosphorus, zinc, copper, vitamin A, vitamin B1 (thiamine), albumin/prealbumin.
— Up to 80% of candidates have at least one micronutrient deficiency at baseline — correct before surgery.
— Pregnancy test (β-hCG) in all reproductive-age women.
— H. pylori testing (stool antigen or urea breath test); eradicate before RYGB to reduce marginal ulcer risk.
— HIV, hepatitis B/C if risk factors.
— ECG in all; transthoracic echo if dyspnea, low functional capacity, known CAD/HF, or pulmonary HTN concern.
— Stress testing per ACC/AHA: poor functional capacity (<4 METs) + elevated surgical risk + would change management.
— Polysomnography for OSA screening — STOP-BANG ≥3 or BMI ≥50; initiate CPAP preoperatively (reduces post-op respiratory failure, atelectasis, atrial fibrillation).
— ABG or venous bicarbonate if obesity hypoventilation syndrome suspected (HCO3⁻ >27 with BMI >40 and daytime hypercapnia).
— EGD is recommended pre-op for many patients, especially symptomatic GERD or planned SG — identifies Barrett esophagus, large hiatal hernia, gastric mass, ulcers.
— Upper GI series or abdominal US if anatomy unclear or RUQ symptoms.
— RUQ ultrasound for gallstones — concurrent cholecystectomy debated; most surgeons treat symptomatic stones, prescribe ursodiol 300 mg BID × 6 months post-op to prevent rapid-weight-loss gallstone formation.
— Required by most insurers and centers of excellence; screens for untreated mood/anxiety/eating disorders, substance use, cognitive capacity for adherence.
Step 3 management: GLP-1 receptor agonists carry delayed gastric emptying and aspiration risk. Current ASA guidance suggests holding weekly agents (semaglutide, tirzepatide) ≥7 days and daily agents the day of surgery. Do not skip this — it is a tested patient-safety detail.
— GERD/Barrett esophagus → favor RYGB (sleeve worsens reflux).
— Severe diabetes, BMI >50, refractory metabolic disease → RYGB or duodenal switch (greater metabolic effect).
— IBD, prior extensive abdominal surgery, need for endoscopic surveillance of stomach (e.g., chronic NSAID dependence, transplant candidate) → favor sleeve.
— Patient on chronic NSAIDs for inflammatory arthritis → avoid RYGB if possible (marginal ulcer).
— Some centers obtain POD 1 upper GI swallow with water-soluble contrast to assess for leak, obstruction, or sleeve stricture — not universally mandated; selective imaging is acceptable.
— Routine drain placement is variable; drain amylase/lipase can detect occult leak.
— Suspected leak: CT abdomen/pelvis with oral and IV contrast (sensitivity ~85%); negative CT does not exclude — if clinical suspicion remains, proceed to diagnostic laparoscopy.
— Suspected internal hernia (late, post-RYGB): CT with "swirl sign" of mesenteric vessels — highly specific. MRI or diagnostic laparoscopy if CT non-diagnostic but suspicion high.
— Suspected marginal ulcer: EGD is diagnostic and therapeutic.
— Suspected stricture (SG incisura, RYGB gastrojejunal): EGD ± fluoroscopic upper GI.
— Bleeding: CT angiography for stable patients with melena/hematochezia; EGD for upper GI bleeding (note: excluded gastric remnant after RYGB is endoscopically inaccessible — may need IR or surgery).
— Post-op leukocytosis, rising CRP, lactate, or unexplained tachycardia → escalate workup.
— Late: annual CBC, iron studies, ferritin, B12, folate, 25-OH vitamin D, PTH, calcium, magnesium, zinc, copper, vitamin A; bone density (DXA) at 2 years and as indicated.
CCS pearl: On the CCS case, a post-op day 2 RYGB patient with HR 130, low-grade fever, and left shoulder pain — order CT abdomen/pelvis with oral and IV contrast, surgery consult STAT, NPO, IV fluids, broad-spectrum antibiotics, type and cross. Do not order a barium swallow (use water-soluble) and do not "watch overnight."
— MBSAQIP risk calculator (Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program) — predicts 30-day morbidity/mortality, leak, reoperation.
— Edmonton Obesity Staging System (EOS): stages 0–4 by metabolic, mechanical, mental health burden; stages 2–3 derive most benefit; stage 4 (end-organ failure) often too high-risk.
— OS-MRS (Obesity Surgery Mortality Risk Score): 5 factors — age >45, male, BMI ≥50, HTN, VTE risk; predicts 30-day mortality.
— Direct patients to MBSAQIP-accredited Center of Excellence — lower mortality, leak rates, readmissions; required by many insurers and Medicare for coverage.
— Sleeve gastrectomy: technically simpler, no malabsorption, no anastomosis, preserved pylorus, easier endoscopic access. Drawbacks: worsens or causes GERD, less durable weight loss than RYGB long-term, irreversible.
— RYGB: gold standard for durable weight loss + diabetes remission + GERD control. Drawbacks: anastomotic leak/ulcer/stricture, internal hernia, dumping, malabsorption requiring lifelong supplements, excluded remnant not endoscopically accessible.
— Duodenal switch / SADI-S: greatest weight loss and diabetes remission; highest nutritional deficiency risk; reserved for super-obese or revisional cases.
— Adjustable gastric band: largely abandoned due to slippage, erosion, reoperation.
— Transplant candidate with obesity: SG often preferred (preserves drug absorption predictability).
— IBD: avoid RYGB; SG preferred.
— Adolescent: SG and RYGB both acceptable in adolescent COE.
Board pearl: A patient with BMI 42, T2DM A1c 9.5%, and severe GERD with Barrett esophagus should undergo RYGB, not sleeve. Sleeve worsens reflux and accelerates Barrett progression; RYGB diverts acid and is the reflux-friendly metabolic operation.
— Hold weekly GLP-1 RA ≥1 week; daily GLP-1 hold day of surgery (aspiration risk per ASA 2023).
— Hold SGLT2 inhibitors ≥3–4 days pre-op (euglycemic DKA risk).
— Discontinue estrogen-containing OCPs ≥4 weeks pre-op (VTE risk); switch to barrier or progestin-only.
— Hold ACEi/ARB the morning of surgery (intraop hypotension).
— Tobacco cessation ≥6 weeks; cessation pharmacotherapy (varenicline, NRT) as needed.
— All bariatric patients receive chemoprophylaxis: enoxaparin 40 mg SC q12h (often weight-based; consider 60 mg q12h for BMI >50), or unfractionated heparin if renal dysfunction.
— Sequential compression devices, early ambulation (POD 0).
— Extended prophylaxis (post-discharge ≥10–14 days) for high-risk: BMI >50, prior VTE, OHS, immobility, hypercoagulable state.
— Cefazolin (weight-dosed: 2 g if <120 kg, 3 g if ≥120 kg) within 60 min of incision; redose if procedure >4 h or EBL >1500 mL.
— Multimodal: acetaminophen, regional blocks (TAP), gabapentinoids, limited opioids.
— NSAIDs are contraindicated lifelong after RYGB (marginal ulcer); use cautiously short-term after SG.
— PPI prophylaxis post-RYGB and post-SG for ≥3–6 months (some recommend ≥1 year or indefinitely after RYGB) to prevent marginal/stomal ulcer.
— Insulin requirements fall dramatically within days (especially RYGB) — proactively reduce basal insulin ~50%, hold sulfonylureas, continue metformin if tolerated.
— Reassess A1c at 3 months; many patients achieve remission and discontinue agents.
Step 3 management: A patient on warfarin for AFib post-RYGB has erratic INRs. Switch to a DOAC with caution — apixaban has the most favorable absorption data after RYGB; avoid dabigatran (poor absorption). Document INR/anti-Xa as appropriate and counsel on follow-up.
— Vertical resection along bougie (typically 36–40 Fr) from antrum to angle of His; ~75–80% of stomach removed; preserves pylorus; staple line buttressed/oversewn at surgeon discretion.
— High-pressure tube → reflux risk, sleeve stenosis at incisura angularis.
— 30 mL gastric pouch, Roux limb 75–150 cm, biliopancreatic limb 30–50 cm, jejunojejunostomy creates excluded remnant + biliopancreatic drainage.
— Three potential internal hernia spaces: Petersen defect, jejunojejunal mesenteric defect, transverse mesocolon defect (in retrocolic technique).
— Anastomotic/staple-line leak: hemodynamically stable + contained → percutaneous drainage + NPO + abx + endoscopic stent or clip. Unstable or diffuse peritonitis → OR for washout, repair, drain placement, feeding jejunostomy.
— Sleeve stenosis: endoscopic pneumatic balloon dilation; refractory → conversion to RYGB.
— Marginal ulcer (RYGB): high-dose PPI + sucralfate, stop NSAIDs/tobacco, treat H. pylori; refractory/perforated → surgical revision.
— Internal hernia: surgical emergency — diagnostic laparoscopy with reduction and closure of all mesenteric defects.
— Cholelithiasis: laparoscopic cholecystectomy when symptomatic; ursodiol prophylaxis during rapid weight loss phase.
— Hypoglycemia (post-bariatric): dietary low-glycemic + acarbose; refractory → diazoxide, octreotide, GLP-1 antagonist (exendin 9-39 in trials); rarely pancreatectomy.
— Intragastric balloon, endoscopic sleeve gastroplasty — for BMI 30–40 not candidates or declining surgery.
CCS pearl: Post-RYGB patient at 9 months presents with intermittent crampy periumbilical pain, nausea, and a CT showing mesenteric "swirl sign" — diagnosis is internal hernia. Order NPO, IV fluids, NG decompression, surgery consult emergently, OR for diagnostic laparoscopy. Delay risks bowel infarction.
— No strict age cutoff; biological age and functional status > chronologic age.
— Outcomes comparable in carefully selected ≥65: weight loss is somewhat less, but comorbidity improvement (T2DM, OSA, HTN, joint function) remains substantial.
— Higher risk: cardiopulmonary complications, VTE, malnutrition, sarcopenia, frailty.
— Pre-op frailty assessment (Fried criteria, 5-meter gait speed); prehabilitation with resistance training and protein optimization.
— Favor sleeve in many elderly (lower anastomotic risk, simpler nutritional management, fewer late surgical emergencies).
— Aggressive protein (≥60–80 g/d) and vitamin D/calcium to prevent sarcopenia and osteoporosis.
— Obesity-related glomerulopathy and diabetic nephropathy frequently improve post-op.
— CKD stages 3–5: bariatric surgery often improves transplant candidacy by lowering BMI below center thresholds (commonly <35–40).
— Medication clearance changes: dose-adjust LMWH (enoxaparin to 30 mg daily or use UFH for CrCl <30), avoid NSAIDs absolutely, careful contrast use.
— Monitor for oxalate nephropathy post-RYGB and BPD-DS — fat malabsorption increases enteric oxalate absorption → calcium oxalate stones and CKD progression. Counsel high fluid intake, calcium with meals (binds oxalate), low-oxalate diet.
— NAFLD/NASH prevalent (~70–90%); often improves dramatically post-op.
— Compensated cirrhosis (Child A) with portal HTN absent: bariatric surgery feasible at experienced centers — SG often preferred (avoids varices around anastomoses, simpler anatomy if transplant later needed).
— Decompensated cirrhosis (Child B/C): contraindicated outside transplant centers; consider combined or staged liver transplant.
— Pre-op screen: liver elastography, MELD, varices EGD when indicated.
Key distinction: SG, not RYGB, is generally preferred in patients with cirrhosis or who may need future liver transplant — preserves endoscopic access for varices, simpler anatomy, no malabsorption affecting immunosuppressants (tacrolimus absorption is unpredictable after RYGB).
— Defer pregnancy ≥12–18 months post-op during rapid weight loss to avoid fetal nutritional compromise and IUGR.
— Pregnancy outcomes overall improved vs obese controls: lower rates of gestational diabetes, preeclampsia, macrosomia. Higher rates of SGA infants and nutritional deficiencies.
— Contraception: avoid oral OCPs after RYGB (malabsorption) — use IUD, implant, depot, patch, or ring.
— Prenatal supplementation: prenatal vitamin plus additional B12, iron, folate, calcium, vitamin D, thiamine; check labs each trimester.
— Pregnant patient with abdominal pain after RYGB → think internal hernia (gravid uterus shifts mesentery). Low threshold for surgical consult and imaging; MRI preferred to limit fetal radiation.
— Avoid 1-h glucose challenge with 50 g glucola in RYGB patients (dumping) — use HbA1c, fasting glucose, or home glucose monitoring for gestational diabetes screening.
— Teen-LABS data: durable weight loss, T2DM remission, HTN improvement at 5 years.
— Indications: BMI ≥120% of 95th percentile + major comorbidity, or ≥140% regardless.
— Multidisciplinary pediatric program required; assess Tanner stage, growth completion not required.
— Adherence and parental support are central; SG and RYGB both used.
— Stable, treated depression/anxiety not a contraindication.
— Active psychosis, untreated bipolar, current substance use → defer.
— Post-op suicide risk is elevated; screen at every visit.
— RYGB increases alcohol bioavailability and AUD risk; counsel abstinence or extreme moderation, especially in years 1–2.
Board pearl: A 28-year-old G2P1, 14 months post-RYGB, presents at 22 weeks gestation with intermittent severe periumbilical pain and vomiting. Internal hernia is the diagnosis until disproven — surgical consult and MRI, not "morning sickness" or expectant management.
— Anastomotic/staple-line leak (1–3%): tachycardia, fever, abdominal/shoulder pain, sepsis. Mortality if missed.
— Bleeding (1–4%): intraluminal (melena, hematemesis) vs intraabdominal (drop Hgb, hemodynamic instability).
— VTE/PE (~0.5–1%): leading cause of 30-day mortality.
— Wound infection, atelectasis, pneumonia, rhabdomyolysis (prolonged lithotomy, BMI >50 — check CK if back/buttock pain).
— Acute gastric remnant dilation (RYGB): dilation of bypassed stomach via JJ obstruction — emergent decompression.
— Internal hernia (RYGB): months to years post-op; "swirl sign"; risk of bowel necrosis.
— Marginal ulcer (RYGB): 1–16%; epigastric pain, bleeding, perforation; risks = smoking, NSAIDs, H. pylori, tension on anastomosis.
— Sleeve stenosis/strictures: dysphagia, regurgitation.
— GERD post-SG: up to 30%; refractory cases → conversion to RYGB.
— Cholelithiasis: up to 30% during rapid weight loss; ursodiol prophylaxis.
— Dumping syndrome (early and late).
— Nutritional deficiencies: iron (most common, especially menstruating women), B12, folate, thiamine (with persistent vomiting), vitamin D, calcium → secondary hyperparathyroidism and osteoporosis, vitamin A (night blindness), copper (myeloneuropathy, cytopenias), zinc, protein-calorie malnutrition (esp. duodenal switch).
— Post-bariatric hypoglycemia (hyperinsulinemic, late dumping).
— Weight regain (~20–30% by 5–10 years).
— Psychiatric: increased suicide, AUD, self-harm risk — actively monitor.
— Accelerated bone loss; DXA at 2 years and as indicated; ensure calcium 1200–1500 mg/d, vitamin D titrated to 25-OH >30 ng/mL.
Key distinction: Wernicke encephalopathy can occur as early as weeks after bariatric surgery if persistent vomiting prevents thiamine repletion. Any post-bariatric patient with vomiting + neurologic symptoms → empiric IV thiamine BEFORE glucose.
— Peritonitis, hemodynamic instability, septic shock in post-op bariatric patient → OR for diagnostic laparoscopy without delay.
— Free air on imaging or expanding abscess unsuitable for percutaneous drainage.
— Suspected internal hernia with ischemia signs (lactic acidosis, peritonitis).
— Massive GI bleed unresponsive to resuscitation.
— Suspected PE with hemodynamic compromise → ICU, consider catheter-directed therapy or thrombolysis.
— Severe OSA/OHS with respiratory failure post-op, sepsis, septic shock, hemodynamic instability, post-cardiac arrest, severe rhabdomyolysis with AKI, anastomotic leak with sepsis.
— Persistent tachycardia >120 unexplained → at minimum step-down monitoring while workup proceeds.
— Bariatric surgeon (operating surgeon ideally) for any post-op complication — early involvement.
— Interventional radiology: percutaneous drainage of contained leaks/abscesses.
— Gastroenterology: endoscopic management of leaks (stents, clips, OTSC), strictures (dilation), bleeding, marginal ulcers, post-bariatric hypoglycemia evaluation.
— Nutrition/dietitian: every patient — pre-op and lifelong.
— Psychiatry/behavioral health: BED, depression, AUD, suicidality.
— Endocrinology: complex diabetes management, hypoglycemia, osteoporosis, secondary hyperparathyroidism.
— Cardiology, pulmonology, hepatology, nephrology, OB: as comorbidities dictate.
— Discharge after uncomplicated SG/RYGB: typically POD 1–2 with clear instructions, ambulation goals, hydration targets (≥64 oz/d), and explicit return precautions (tachycardia, fever, persistent vomiting, abdominal pain, shoulder pain, leg swelling).
Step 3 management: A post-op day 5 patient discharged on POD 2 calls with HR 118 at rest and mild epigastric pain. Do not reassure or schedule routine follow-up — direct to the ED, alert the bariatric surgery team, anticipate imaging for leak/PE. Delayed leak presentations occur after discharge and require urgent evaluation.
— Anastomotic leak (early): tachycardia, fever, peritonitis.
— Marginal ulcer: epigastric pain, often months out; melena; smokers/NSAIDs; H. pylori.
— Internal hernia (RYGB): intermittent crampy pain, can be subtle; "swirl sign."
— Stricture (gastrojejunal or sleeve incisura): dysphagia, postprandial vomiting, food intolerance.
— Cholelithiasis / choledocholithiasis: postprandial RUQ, fatty food intolerance — common during rapid weight loss.
— Intussusception at JJ anastomosis: rare, intermittent crampy pain.
— Gastrogastric fistula (RYGB): weight regain, recurrent ulcers, return of acid reflux.
— Stricture, sleeve stenosis, marginal ulcer, internal hernia, gastric outlet obstruction, dehydration, eating behaviors (overeating, inadequate chewing), motility disorder, candidal esophagitis, thiamine deficiency, pregnancy.
— Early dumping (15–30 min): vasomotor, not true hypoglycemia.
— Late dumping / post-bariatric hyperinsulinemic hypoglycemia (1–3 h post-meal): document Whipple triad; 75 g mixed meal test preferred over OGTT (OGTT contraindicated).
— Rule out insulinoma, adrenal insufficiency, factitious causes.
— Dietary lapse, pouch dilation, gastrogastric fistula (RYGB), sleeve dilation, hormonal adaptation, untreated BED, medication-induced (steroids, atypical antipsychotics).
Board pearl: A 2-year post-RYGB patient with return of GERD, epigastric pain, and regain of weight — suspect gastrogastric fistula. Diagnose with upper GI series or EGD; management is surgical revision.
— Acute coronary syndrome: post-op MI in obese diabetics can present atypically — get ECG and troponin in any new tachycardia, dyspnea, or epigastric pain.
— Pulmonary embolism: still the #1 cause of 30-day post-bariatric mortality — must rule out with CTPA or V/Q in any unexplained tachycardia, hypoxia, or pleuritic pain.
— Pneumonia, atelectasis (especially with OSA/OHS).
— Aspiration pneumonitis (especially with retained GLP-1 effect).
— Acute pancreatitis: gallstone, hypertriglyceridemia.
— C. difficile colitis: recent perioperative antibiotics.
— Acute mesenteric ischemia: especially in older patients with AFib.
— Bowel obstruction from adhesions (any prior abdominal surgery), incisional or port-site hernia.
— Diverticulitis, appendicitis, ovarian pathology — do not anchor on bariatric anatomy.
— DKA/HHS (especially after holding SGLT2 inadequately, or new-onset T1DM).
— Adrenal insufficiency (chronic steroids).
— Hyponatremia from excess hypotonic fluid intake (post-bariatric patients drink small volumes frequently).
— Wernicke encephalopathy from thiamine deficiency.
— Copper deficiency myeloneuropathy mimicking B12 deficiency.
— Idiopathic intracranial hypertension may improve post-op — but new headaches with vomiting should still prompt workup.
— Bariatric surgery does not eliminate cancer risk; age-appropriate screening continues. Endometrial, breast, colorectal cancer rates fall after surgery but remain present.
Key distinction: A post-RYGB patient with macrocytic anemia + paresthesias could be B12 deficiency (most common) or copper deficiency (mimics B12 with myelopathy and cytopenias including neutropenia). Check both, plus zinc (high zinc supplementation can cause copper deficiency).
— PPI (omeprazole 20–40 mg daily) for ≥3–6 months (longer/indefinite for RYGB or marginal ulcer risk).
— Enoxaparin extended prophylaxis 10–14 days if high VTE risk.
— Ursodiol 300 mg BID × 6 months during rapid weight loss (gallstone prevention) unless cholecystectomy performed.
— Antiemetic (ondansetron) PRN short-term.
— Avoid NSAIDs (lifelong after RYGB).
— Adjust diabetes meds (reduce/stop insulin and sulfonylureas; continue metformin).
— Adjust antihypertensives (anticipate hypotension as weight falls).
— Switch contraception away from oral if RYGB.
— Bariatric multivitamin with iron (2 daily for RYGB/DS, 1–2 for SG; ensure adequate B-complex including thiamine).
— Calcium citrate 1200–1500 mg/d in divided doses (not carbonate — needs acid for absorption).
— Vitamin D 3000 IU/d titrated to 25-OH >30 ng/mL.
— Vitamin B12 500 µg sublingual daily or 1000 µg IM monthly (especially RYGB).
— Iron 45–60 mg elemental daily (more for menstruating women); separate from calcium.
— Additional ADEK after duodenal switch.
— Counsel protein intake 60–80 g/d (≥80–100 g for DS).
— Structured exercise: aerobic + resistance training to preserve lean mass; goal ≥150 min/week.
— Hydration ≥64 oz/d, sipped (not gulped) between meals.
— Avoid carbonated beverages, straws, lying flat after eating.
— Abstain from alcohol ≥1–2 years; then strict moderation.
— Smoking cessation, lifelong.
— Continue age-appropriate screening: mammography, cervical, colonoscopy, lung CT if eligible.
— Vaccinations updated; influenza annually; COVID-19, pneumococcal, shingles per age.
Step 3 management: A 38-year-old woman 18 months post-RYGB on oral OCP presents with unintended pregnancy. The root issue is OCP malabsorption after RYGB — counsel transition to IUD, implant, or non-oral hormonal method, and emphasize this is a known patient-safety hazard at every post-op visit.
— Surgical follow-up: 2 weeks, 6 weeks, 3 months, 6 months, 12 months, then annually.
— Nutrition follow-up parallels surgical; dietitian visits at each.
— Behavioral health: as needed; routine screening for depression, AUD, BED, suicidality.
— Primary care: coordinate comorbidity de-escalation (diabetes, HTN, lipids, sleep apnea).
— 3, 6, 12 months, then annually: CBC, CMP, iron studies/ferritin, B12, folate, 25-OH vitamin D, PTH, calcium, magnesium, phosphorus, lipid panel, HbA1c.
— Annual or per symptoms: thiamine, zinc, copper, vitamin A (especially DS); selenium if symptomatic.
— DXA scan at 2 years post-op and as clinically indicated.
— Sleep study reassessment at 12–18 months — many patients can wean CPAP after substantial weight loss.
— RYGB: 60–70% excess weight loss at 1–2 years, ~50% durable at 10 years.
— SG: 50–60% EWL at 1–2 years; somewhat less durable.
— Plateau typically at 12–18 months; address regain early with re-engagement, dietitian, behavioral support, or pharmacotherapy (GLP-1 RA after surgery is increasingly used; cautious in early post-op).
— Pregnancy planning: defer 12–18 months; reinforce non-oral contraception (RYGB).
— Alcohol risk (especially RYGB).
— Mental health vigilance: increased suicide risk.
— Skin and body image: discuss panniculectomy/body contouring after weight stabilization (usually ≥18 months and stable weight ≥6 months); insurance coverage variable.
— Encourage supervised exercise program; physical therapy for joint/back pain; cardiac rehab if applicable.
Board pearl: At 2 years post-bariatric surgery, order a DXA scan; many patients develop early osteopenia/osteoporosis from accelerated bone turnover, vitamin D deficiency, and secondary hyperparathyroidism — even with normal-appearing calcium levels.
— Document understanding of irreversibility (SG) or anatomic permanence (RYGB), lifelong supplementation, lifestyle change, and specific risks: leak, bleeding, VTE, internal hernia, marginal ulcer, nutritional deficiencies, hypoglycemia, weight regain, increased AUD and suicide risk.
— Capacity assessment — particularly important in adolescents and patients with cognitive impairment; obtain parental consent and adolescent assent for minors.
— Discuss expected vs unrealistic outcomes; bariatric surgery is a tool, not a cure.
— Post-discharge tachycardia is a sentinel event commonly missed when patients are managed by non-bariatric clinicians; provide a clear handoff to the PCP including return-precaution criteria and a 24/7 contact line.
— Patients presenting to outside EDs with abdominal pain after bariatric surgery face delays in diagnosis (internal hernia, leak missed). Provide patients with a wallet card or written summary of their anatomy and surgeon contact.
— NSAIDs after RYGB → marginal ulcer/perforation. Document allergy/contraindication in EHR.
— OCP failure after RYGB → unplanned pregnancy in rapid-weight-loss window with fetal risk.
— GLP-1 RA aspiration risk — verify hold dates.
— Insulin and sulfonylurea hypoglycemia post-op — proactive de-escalation prevents harm.
— Disclosure of complications and errors (e.g., retained surgical item, wrong-site marking) per institutional and state requirements; document open conversation with patient/family.
— Pediatric patients with concerns for neglect or food insecurity — connect to social work.
— Bariatric surgery is underutilized in eligible populations; disparities in access by race, sex, insurance — advocate for referral when indicated, and document medical necessity carefully.
— Patient autonomy permits declining surgery despite indication; respect and re-engage with non-surgical optimization (GLP-1 RA, lifestyle, behavioral therapy).
Step 3 management: A post-RYGB patient is seen in an ED 200 miles from her surgical center for vague abdominal pain. The safest action is CT with contrast and bariatric surgery telephone consultation — not "follow up with your surgeon Monday." This transition-of-care risk is the most tested ethics/safety pattern in bariatric Step 3 vignettes.
— BMI thresholds: ≥35 alone, or ≥30 with metabolic disease (2022 update).
— 30-day mortality: ~0.1–0.3% (lower than appendectomy in accredited centers).
— Leak rate: ~1–3%; bleeding ~1–4%; VTE ~0.5–1%.
— T2DM remission at 1 year: RYGB ~60–80%, SG ~50–70%.
— Excess weight loss: RYGB ~65%, SG ~55% at 1–2 years.
— Iron, B12, folate, calcium, vitamin D → all bariatric procedures, worst with RYGB and DS.
— Thiamine → any procedure with persistent vomiting (give IV thiamine empirically).
— Fat-soluble (A, D, E, K) → duodenal switch > RYGB > SG.
— Copper → RYGB and DS; excess zinc supplementation can induce copper deficiency.
— Protein-calorie malnutrition → DS most.
— Tachycardia POD 1–3 → leak.
— Hypoxia + tachycardia POD 0–7 → PE.
— Crampy abdominal pain months–years post-RYGB + "swirl sign" → internal hernia.
— Smoker post-RYGB with epigastric pain or melena → marginal ulcer.
— Dysphagia post-SG → sleeve stenosis at incisura.
— Weight regain + reflux + recurrent ulcer post-RYGB → gastrogastric fistula.
— Postprandial flushing/cramping 30 min → early dumping.
— Postprandial hypoglycemia 2 h → late dumping / post-bariatric hypoglycemia.
— Ataxia + confusion + ophthalmoplegia in a vomiting post-op patient → Wernicke (give IV thiamine).
— Night blindness post-DS → vitamin A deficiency.
— Macrocytic anemia + neutropenia + myelopathy → copper deficiency.
— Apixaban preferred DOAC after RYGB.
— Avoid oral OCPs after RYGB.
— Calcium citrate (not carbonate) after RYGB and SG.
— Hold GLP-1 RA ≥1 week (weekly) preoperatively.
Board pearl: The exam's favorite three "miss-it-and-the-patient-dies" diagnoses after bariatric surgery are anastomotic leak (early), pulmonary embolism (early), and internal hernia (late). Pattern-match tachycardia + the timeline.
— 46-year-old, BMI 32, A1c 9.0% on metformin + GLP-1, OSA on CPAP, HTN on 3 agents. Best next step?
— Answer: Refer for metabolic/bariatric surgery evaluation (BMI ≥30 with uncontrolled T2DM meets 2022 criteria).
— POD 2 after RYGB: HR 124, T 100.9°F, mild abdominal and left shoulder pain, WBC 17. Best next step?
— Answer: CT abdomen/pelvis with oral and IV contrast and surgical re-exploration if positive or clinical suspicion persists.
— 9 months post-RYGB, intermittent severe periumbilical pain, normal labs, CT with "swirl sign" of mesenteric vessels. Next step?
— Answer: Urgent diagnostic laparoscopy with reduction and closure of mesenteric defects.
— 8 months post-RYGB smoker with epigastric pain and melena. Diagnostic and management?
— Answer: EGD; high-dose PPI, sucralfate, smoking cessation, treat H. pylori, NSAID cessation.
— Post-RYGB patient with diaphoresis, tremor, confusion 2 hours after meals, normal fasting glucose. Test?
— Answer: Mixed-meal tolerance test (not OGTT); manage with low-glycemic diet ± acarbose.
— Post-SG patient 6 weeks out with persistent vomiting, now ataxic and confused with ophthalmoplegia. First action?
— Answer: IV thiamine before glucose; suspect Wernicke encephalopathy.
— Reproductive-age woman 1 year post-RYGB on oral OCP. Counseling?
— Answer: Switch to non-oral contraception (IUD, implant); defer pregnancy until 18 months post-op.
— Scheduled for sleeve gastrectomy next week, on weekly semaglutide. Management?
— Answer: Hold semaglutide ≥1 week before surgery to reduce aspiration risk.
— BMI 44 with Barrett esophagus and severe GERD. Best procedure?
— Answer: RYGB, not sleeve.
Step 3 management: Pattern-recognize stems by post-op timeline: hours–days (bleed, leak), weeks (thiamine, early stricture), months (marginal ulcer, gallstones), years (internal hernia, regain, deficiencies, fistula, hypoglycemia).
Bariatric surgery is a guideline-endorsed, durable treatment for obesity and metabolic disease at BMI ≥35 (or ≥30 with comorbidity) whose success depends equally on rigorous multidisciplinary pre-op selection, vigilant recognition of early (leak, bleed, PE) and late (internal hernia, marginal ulcer, dumping, hypoglycemia, nutritional deficiency) complications, and lifelong supplementation and follow-up.