Clinical Pearls in Managing Bariatric Surgical Emergencies

| June 18, 2009

by J.K. Champion, MD, FACS

Dr. Champion is Director of Bariatric Surgery, Northside Hospital, Atlanta, GA and Clinical Professor of Surgery, Mercer University School of Medicine, Macon, Georgia.

Introduction
Bariatric surgery—no matter the procedure, no matter the surgeon with however much experience—will result in complications and surgical emergencies. The average incidence of in-hospital complications after bariatric surgery, as reported by Livingston,[1] is approximately 10 percent, and the American Society for Metabolic and Bariatric Surgery Centers of Excellence program (ASMBS SRC) reports a 90-day incidence of readmissions of 4.7 percent and a reoperation rate of 2.6 percent in its initial review of the first 106 centers approved.

These numbers probably reflect an ideal, and underestimate the true incidence depending on the geographic area, availability of resources to manage the bariatric patient, and the demographics of the patient population. We also recognize a subset of bariatric surgery patients with increased morbidity and mortality risk if they demonstrate a BMI >60, are over 50 years of age, have multiple comorbidities (especially pulmonary, cardiac, or hypertension), are male gender, or are revision patients.[2,3] problem we have faced as bariatric surgeons is a generalized lack of experience among many general surgeons in managing complex gastric surgery patients and bariatric surgery patients in particular as the volume of procedures has exploded over the past decade. Gastric surgery was becoming a lost art in the 1990s, and bariatric surgery was principally performed in the private practice setting, so a generation of general surgeons entered the field never having performed a bariatric procedure or managed a bariatric surgery patient in their residency program. We faced a shortage of trained bariatric surgeons as the laparoscopic approach revitalized the public’s interest in the surgical management of obesity, and general surgeons rushed in to fill the void, with little exposure other than a weekend lecture and tissue lab. As a result, complications flourished, especially with the more technically challenging laparoscopic procedures, and surgeons relied on their general surgery training to guide them in managing these problems, which, in many cases, resulted in poor outcomes.

There are principles that can assist surgeons and guide management of this challenging subset of patients (Table 1). Morbidly obese patients are not general surgery patients and they do not exhibit the signs and symptoms commonly expected. Their body habitus makes a physical exam difficult, and they often do not fit on current radiologic and diagnostic tables. Vital signs, laboratory tests, and radiologic exams we normally rely on may be normal in the face of serious complications, such as overwhelming sepsis or ischemic bowel, until the patient suddenly deteriorates and dies. Due to their associated comorbidities, postoperative bariatric patients have no functional reserve to weather a complication, so a seemingly minor complication can quickly escalate to a life-threatening one or initiate a cascade of associated problems.

Bariatric surgery patients with complications may rapidly deteriorate and principles of management based on guidelines for treatment of trauma victims work well in our experience. There is no room for medical management of these patients, and the bariatric surgeon needs to be involved early. The concept of a bariatric “golden period” with an aggressive surgical approach to evaluation and initiation of therapy is appropriate. A goal of completing an evaluation within 6 to 12 hours and surgical intervention within 24 hours offers the best opportunity to improve outcomes. The principles of surgical management of bariatric complications are also based on the “damage control laparotomy,” with a goal to stabilize and support the patient in the operating room, recognizing that a prolonged and challenging recovery may follow.

The etiology of bariatric surgical emergencies can be categorized into four major issues, which are likely to result in postoperative mortality if not recognized and treated within the first 24 hours of onset (Table 2). Postoperative bleeding, leaks, obstructions, and pulmonary emboli are the principle complications to be included in the differential diagnosis. Pulmonary emboli are included in the table even though the treatment is medical, since the diagnosis must be ruled out and the symptoms may be similar to leaks or ischemic bowel; however, this article will not review the management.

The challenge for the evaluating surgeon is differentiating the etiology because the initial phone call will not be from a patient stating, “I have a staple line leak from my gastric remnant.” A useful guide is to consider this series of questions: How will the patient present? Can you identify the problem short of a re-exploration? What is the appropriate emergent treatment and stabilization?

How will the patient present?
Surgeons will be told a patient has bleeding, unstable vital signs or sepsis, abdominal pain, or vomiting. These may be subtle and non-specific initially, but serve as red flags that a serious problem may be developing and deserve prompt evaluation and assessment. Bleeding is self evident. Unstable vital signs or sepsis are defined as fever >101°F, hypotension, tachycardia >120 for four hours, tachypnea or carbon dioxide retention, decreased urinary output, or rise in blood urea nitrogen (BUN) and creatinine. Abdominal pain and colic or vomiting that lasts more than four hours also constitutes a call for prompt treatment. The single most important sign of a significant complication after bariatric surgery is a persistent tachycardia >120 for four hours. Patients who present with the previously listed complaints deserve a prompt evaluation, and the evaluations must not delay treatment unduly.

Can you identify the problem short of a re-exploration?
Options include the following: (1) a physical exam and vital signs, which may require a serial exam over the next 6 to 12 hours; (2) labs to include a complete blood count (CBC) and comprehensive chemistry profile; (3) x-ray evaluation to consider a chest x-ray, computed tomography (CT) scan of abdomen and pelvis with oral contrast, and CT scan of the chest with intravenous (IV) contrast, gastrograffin swallow, or barium upper gastrointestinal (UGI) with small bowel follow-through, and ultrasound of the gallbladder (Note: The patient may not fit on exam table); (4) upper endoscopy or esophagogastroduodenoscopy (EGD). All diagnostic studies are frequently negative, so a normal study rules out nothing.

What is the appropriate emergent treatment and stabilization?
Emergency treatment of a patient who shows signs and symptoms of being “sick,” without an identifiable and rapidly correctable etiology (6–12 hours) requires surgical exploration. If the patient presents to another facility or is seen by an on-call surgeon, the primary bariatric surgeon should be contacted even if he or she is not on staff at that facility, as he or she may have critical information that could influence the evaluation or treatment plan. Management of postoperative complications is a surgical emergency and there is no place for medical management, so a surgeon needs to be involved from the onset.

Another source of potential delays may be a tendency by the primary bariatric surgeon to rationalize that the problem cannot be related to the initial operation, or the on-call surgeon may wait for the return of the primary bariatric surgeon, resulting in a delay for 24 to 48 hours until the patient is in extremis before exploratory surgery is considered. Patients are much more likely to die from delays, missed diagnosis, and failure to treat than from a negative exploration. The best opportunity to improve outcomes is aggressive surgical treatment within the first 24 hours, so delays must be avoided in the bariatric surgery population.

Bleeding
Bleeding may present as bright red blood per mouth or rectum, bloody drainage, melena, tachycardia, hypotension, or orthostatic syncope. Early bleeding (first 48 hours) from the gastrointestinal tract is due to the staple lines and may require re-exploration. If it is from a drain site, it may originate from the external staple lines, mesentery, omentum, spleen, or trocar sites. Oral blood usually originates from the proximal pouch, while rectal bleeding comes from the distal stomach or small bowel.[4]

Initial stabilization consists of a bolus of one liter of normal saline, type and cross match for packed red cells, stopping any anticoagulants, checking renal function tests, and ordering serial hematocrits. Insertion of a Foley catheter and placement of a large IV or central line is also indicated.

Bright red bleeding usually requires surgical intervention by EGD or exploratory surgery, especially within the first six hours postoperative. Melena is more likely to be managed with replacement therapy and discontinuation of anticoagulants. Indicators for a return to the operating room include a decrease in hematocrit of 10, decreasing hematocrit despite transfusion, tachycardia >120 for four hours despite a fluid bolus, hypotension despite blood replacement, or greater than 100cc per hour of bloody drainage via a drain.

At the time of surgery, the bleeding invariably stops on induction of anesthesia, so the bleeding site usually will not be identifiable. If there is intraluminal bleeding, perform an EGD first under general anesthesia so there is control of the airway, a careful inspection of the pouch, and so anastomosis is possible. If a definitive bleeding site is identified, then treat with a combination of injection of epinephrine and cauterization. Be aware that there is a significant risk of a perforation of the gastrointestinal (GI) tract with an early postoperative endoscopic manipulation of fresh staple and suture lines. If no bleeding site is seen, then proceed with re-exploration and oversew all staple lines, decompress the GI tract of clots, even if it takes a G-tube, place a drain, and get out. Retained clots can result in a small bowel obstruction and possible gastric remnant leak. If there is intra-abdominal bleeding, evacuate all the clots, perform a meticulous inspection, obtain hemostasis of every bleeding site to include a suture or clip on every site with a clot, consider fibrin glue on the staple lines, and place a drain.

Leaks
Unstable vital signs or signs of sepsis are leaks until proven otherwise. You need to first rule out hypovolemia, atelectasis, bleeding, pulmonary embolism or closed loop, small bowel obstruction all within the first six hours. Start with a physical exam, CBC, renal profile, chest x-ray, gastrograffin swallow, or oral methylene blue test, and consider a CT exam (abdomen with oral contrast and chest with IV contrast) all within the first six hours. Patients will only be able to drink a few ounces of contrast in the early postoperative period, so do not delay the exam waiting on the patient to drink the 32 ounces of contrast the radiology department usually mandates. Keep in mind that physical exam, lab tests, and radiologic exams are usually negative.[5] Gastrograffin swallows are negative in 70 percent of leak exams and CT scans are negative in 50 percent of leaks.[6] A persistent and progressive tachycardia of >120 for over four hours is an indication for emergent surgical exploration despite an otherwise negative evaluation.
Initial stabilization begins with a fluid bolus of one liter of normal saline and early initiation of antibiotic coverage for gram negative and anaerobic bacteria. Aggressive early surgical exploration is the best option once a pulmonary embolus has been ruled out.
Surgical exploration requires inspection of the entire abdomen with an intraoperative leak test of the pouch and gastrojejunostomy. Do not forget to inspect the distal stomach and enteroenterostomy anteriorly and posteriorly. Also look for iatrogenic injuries of the distal bowel or organs, and rule out a closed loop bowel obstruction by running the entire bowel.
If a leak is identified, remember repairs will usually break down, and revisions are ill advised in the face of infection unless there is no recourse. If the leak is less than 24 hours old, attempt a suture repair or omental patch and drain, drain, drain. Have one drain posteriorly in a dependent position for when the patient is supine or on a ventilator. Place a G-tube for decompression and nutritional support. Irrigate profusely, provide broad antibiotic coverage for gram negative and anaerobic bacteria and coverage for candida, establish deep vein thrombosis (DVT) prophylaxis, and begin nutritional support. Remember the principles of damage control laparotomy and leave the abdomen open if there is gross contamination, or if the inspiratory pressure increases more than 10mm on closing the abdomen. Consider reopening the abdomen later if bladder pressure increases above 25mm Hg (Figure 1) or the patient develops respiratory or renal insufficiency, which are signs of abdominal compartment syndrome and will result in multiple organ failure and death if untreated.[7,8] Many patients survive a leak and repair to succumb to the abdominal compartment syndrome postoperatively. Treatment consists of opening the fascia to decompress the abdomen and cover the bowel with a Bogota bag or vacuum-assisted closure device and reassess every 48 hours for possible closure.

Abdominal Pain/Vomiting
Abdominal pain is a common postoperative complaint, as is occasional vomiting from dietary indiscretions, but persistent pain lasting more than four hours or pain associated with vomiting of more than four hours requires prompt evaluation in the emergency room (Figure 2). Closed loop bowel obstructions and internal hernias are unique to gastric bypass patients and can be lethal if dead bowel develops. The initial evaluation may consist of a flat and upright abdominal series, especially in an adjustable gastric band patient, but may be negative with closed loop obstructions after a gastric bypass, so a CT of the abdomen and pelvis with oral contrast or a UGI with small bowel series is more appropriate in this cohort. Be aware of gastrograffin aspiration if a patient goes into surgery after a radiologic study, as it will result in a severe chemical pneumonitis and respiratory insufficiency and may require ventilatory management. Always give the vomiting bariatric patient 100mg of thiamine IV to prevent Wernicke’s encephalopathy and avoid dextrose in the IV until the thiamine is infused. Bariatric surgery patients who present with vomiting and confusion, ataxia or nystagmus, and blurred vision have a neurologic emergency of Wernicke’s encephalopathy and must have IV thiamine and avoid dextrose—or the neurologic deficient will be converted to a permanent irreversible state.
Be aware that many bariatric patients have had other abdominal procedures (especially hysterectomies and Cesarean sections) so consider adhesive or distal obstructions unrelated to the bariatric procedure. Also be aware of the “red herring” of gallstones found on an ultrasound exam in the emergency room on a post-bariatric surgery patient who presents with abdominal colic and vomiting. The real culprit may be a closed loop bowel obstruction, pelvic pathology, or appendicitis, which can be overlooked during a laparoscopic exam unless an effort is made to inspect the entire abdomen and run the bowel completely.
A careful history is required to determine if vomiting is with solids and liquids or only with solids, and whether it is associated with abdominal pain. Progressive vomiting of solids but not liquids, which is not associated with abdominal pain, usually means a stoma stenosis, which can be managed with an EGD. However, vomiting of both solids and liquids requires an evaluation to rule out a small bowel obstruction. A patient with a history of recurrent colic, especially after meals, or prolonged colic requires an exploratory laparoscopy regardless of x-ray findings, which are often negative in this population. There is no place for a nasogastric tube or conservative management in a bariatric surgery patient with a suspected bowel obstruction.
Surgical management consists of an exploratory laparotomy or laparoscopy. The surgeon must be familiar with the anatomy of the bariatric procedure the patient previously underwent. Inspect the entire abdomen and run the entire small bowel. The anatomy may be confusing, particularly in the face of internal hernias, with twisting of the bowel anatomy so the surgeon may need to begin distally at the cecum and work retrograde. Inspect and close all mesenteric defects, and perform an intra-operative EGD to rule out a stoma stenosis.[9]
Laparoscopic adjustable gastric band (LAGB) patients who present with abdominal colic or vomiting can usually be assessed with a flat and upright abdominal series, and the band position is noted. If the band indicates a slippage, the band must be deflated to avoid necrosis, and then confirm the stomach reduces with a barium swallow or gastroscopy. Band deflation is indicated any time a LAGB patient presents with persistent vomiting and can be accomplished with a Huber needle under sterile local anesthesia in the emergency room.

Summary
Complications are a fact of life after bariatric surgery. An aggressive approach to evaluation and early surgical management within the first 24 hours offers the best opportunity to improve outcomes in this high-risk population.

References
1.    Livingston EH. Procedure incidence and in-hospital complication rates of bariatric surgery in the United States. Am J Surg. 2004;188:105–110.
2.    Helling TS, Willoughby TL, Maxfield DM, et al. Determinants of the need for intensive care and prolonged mechanical ventilation in patients undergoing bariatric surgery. Obes Surg. 2004;14:1036–1041.
3.    Fernandez AZ, DeMaria EJ, Tichansky DS, et al. Multivariate analysis of risk factors for death following gastric bypass for treatment of morbid obesity. Ann Surg. 2004;239:698–703.
4.    Nguyen NT, Longoria M, Chalifoux S, et al. Gastrointestinal hemorrhage after laparoscopic gastric bypass. Obes Surg. 2004;14:1308–1312.
5.    Gonzalez R, Nelson LG, Gallagher SF, et al. Anastomotic leaks after laparoscopic gastric bypass. Obes Surg. 2004;14:1299–1307.
6.    Gonzalez R, Sarr MG, Smith CD, et al. Diagnosis and contemporary management of anastomotic leaks after gastric bypass for obesity. J Am Coll Surg. 2007;204:47–55.
7.    Orlando R, Eddy VA, Jacobs LM, et al. The abdominal compartment syndrome. Arch Surg. 2004;139:415–422.
8.    Hunter JD, Damani Z. Intra-abdominal hypertension and the abdominal compartment syndrome. Anaesthesia. 2004;59:899–907.
9.    Champion JK, Williams M. Small bowel obstruction and internal hernias after laparoscopic roux-en-y gastric bypass. Obes Surg. 2003;13:596–600.

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