BY ALEJANDRO E. MACIAS; BILLY ZHANG; KRISTEN HUGHES; SHAMIM KHAN, MD; FRANCISCO JACOME, MD
A 73-year-old man with a past medical history of hypertension, type 2 diabetes, and hyperlipidemia and a surgical history for a coronary artery bypass presented with sudden, severe lower abdominal pain. He characterized his pain as 8/10 and was tender to palpation.
Laboratory studies showed a white blood cell count of 7.51 with a glucose of 759, no bands, a platelet count of 230,000, and a lactic acid level of 6.7. Urinalysis showed +5 ketones and a glucose count of greater than 500. An abdominal CT showed possible microperforations around the cecum. The patient also had electrocardiogram changes indicative of an abnormality in the inferior wall of the heart. The patient was given 1 g of ertapenem and 1 g of ceftriaxone, and was placed on a bicarbonate drip. The clinical impression at this point was shock (septic vs cardiac).
The patient was taken emergently to the catheterization lab to rule out acute coronary artery disease. Severe three-vessel coronary artery disease, totally occluded third vein graft, and moderate to severe reduced left ventricular function with an ejection fraction of 30 to 35 percent were found. The patient was transferred to the intensive care unit, where he was evaluated by surgery. His blood pressures was in the 70s, and he was tachycardic and tachypneic. A central line was placed and dobutamine, levophed, and two liters of normal saline were administered with appropriate caution to the patient's compromised ejection fraction.
An exploratory laparotomy was scheduled. The preoperative diagnosis was a perforated diverticulitis. Ascites was drained during the procedure, and the drained fluid was brown in color without odor. No indurations were felt while palpating the abdomen, but gross contamination of the abdomen was evident. A large 3 cm stercoral ulcer with a hard, rock-like stool was identified when palpation continued toward the left colon around the sigmoid area.
Stercoral ulcers are defined as perforations of the large bowel due to pressure necrosis from fecal impaction. (Curr Gastroenterol Rep 2014;16:404.) Fewer than 100 cases of stercoral ulcers have been documented. (G Chir 2011;32[8-9]:368.) Perforation most often occurs at the antimesenteric border of the sigmoid colon and rectosigmoid junction because this area has a narrower lumen, decreased blood flow, and the driest stool, increasing susceptibility to rupture. Rupture has occurred at other locations, however. (Am Surg 2012;78:E515.)
These patients generally present with a history of chronic constipation, and many have a history of opioid medication use or abuse or other constipating agents along with the use of laxatives or enemas in the past. (G Chir 2011;32[8-9]:368.) Most cases are of elderly patients, but a case of a 25-year-old man with chronic constipation leading to stercoral ulcer perforation has been documented. (South Med J 2006;99:525.)
The rupture of the colon subsequently leads to the release of fecal material into the peritoneal cavity, leading to peritonitis and signs of acute abdomen supported by radiographs demonstrating peritoneal free air. (Am Surg 2012;78:E515.) There have been cases of stercoral ulcers without perforation through the lumen, which instead presented with gastrointestinal bleeding. (CMAJ 2011;183:E134.)
The treatment for stercoral ulcer perforation involves emergent exploratory laparotomy with resection of the affected colon along with repeated abdominal washout to remove feces. A colostomy is performed along with formation of a mucus plug. (South Med J 2006;99:525.) Parenteral antibiotics are required during this procedure because of seeding of bacteria into the bloodstream, which inevitably leads to sepsis. (Am Surg 2012;78:E515.)
The criteria of a systemic inflammatory response syndrome (SIRS) must be met to determine whether a patient is septic. (JAMA 2016;315:775.) These criteria are two or more of the following:
* Temperature >38°C or <36°C
* Heart rate >90/min
* Respiratory rate >20 or PaCO2 <32 mm Hg
* WBC count >12,000/mm3 or <4,000/mm3 or >10% immature band cells
Contrast-enhanced axial CT scan demonstrates extraluminal gas (arrow) in the ileocecal area indicating perforation.
A quick sequential organ failure assessment (qSOFA) can be used to aid in assessing the severity of organ failure and mortality rates. A qSOFA ≥2 has been correlated with a 10 percent increase in mortality. The qSOFA criteria are:
* Respiratory rate ≥22/min
* Altered mentation
* Systolic blood pressure ≤100 mm Hg
The criteria for a patient to be in septic shock are:
* Meet the criteria for sepsis
* Hypotension and requiring vasopressors to maintain MAP ≥65 mm Hg
* Lactate levels >2 mmol/L
All these criteria must be met despite adequate volume resuscitation, and are associated with an increase in mortality more than 40 percent. (JAMA 2016;315:775.) The mortality rates of sepsis are higher among adults over 60. Those who survive often experience a decline in functional status in the first year after discharge. (Open Forum Infect Dis 2016;3:ofw010.)
Treatment of septic shock is centered around maintaining perfusion of organs and preventing the three septic shock criteria from occurring. This is done by fluid resuscitation, use of vasoactive drugs, and red cell transfusion. A meta-analysis looking into early goal-directed therapy rather than waiting for symptoms to occur and treating accordingly found no difference in mortality rates. (N Engl J Med 2015;372:1301.) This patient demonstrated a case of stercoral ulcer perforation, which subsequently led to severe septic shock in an elderly man with an extensive past medical history.
A Must for Differential Diagnosis
The affected areas were transected, which included the ulcerated and contaminated parts of the mesentery, small bowel, and colon. The abdomen was irrigated with about 15 liters of normal saline until the fluid became completely clear. A circular incision was made on the left lower quadrant through all layers of the abdomen, and the proximal aspect of the colon was brought out to complete a colostomy. Lastly, a Jackson-Pratt drain was placed in the pelvis.
No significant changes were observed over the next five days; the patient remained in critical condition with shock, on a ventilator with multiple medications for blood pressure support, and strict NPO. On postoperative day five, the patient developed worsening hypotension, bradycardia, hypoxemia despite maximum vasopressors, bicarbonate, steroids, antibiotics, and intravenous fluid resuscitation. Subsequently, the patient's family requested a DNR; continuous renal replacement therapy was discontinued five minutes later. The patient showed no signs of life and was pronounced dead after 15 minutes.
Chronic constipation leading to fecal impaction is potentially life-threatening. Risk factors for fecal impaction include the elderly, incapacitated patients, and the use of constipating agents. Fecal impaction, if not promptly discovered and treated, can lead to complications of feces leakage or stercoral ulcer rupture. Ruptured stercoral ulcer has a very high mortality due to severe peritonitis and septic shock. (Curr Gastroenterol Rep 2014;16:404.) The risk factors for stercoral ulcer perforation should be identified in patients who are high-risk for prevention and resolution of the underlying constipation.
Contrast-enhanced sagittal CT scan demonstrates the site of the perforation and a fecaloma (arrow) in the proximal sigmoid colon, and due to pressure necrosis, signs of adjacent colonic wall thickening (arrowhead) are noticed.
It is also important to be aware of the different presentations of stercoral ulcers. If the ulcer has not completely ruptured, it may present as chronic constipation with accompanying rectal bleeding. (CMAJ 2011;183:E134.) Stercoral ulcers also have no underlying pathology because they occur without any polyps or colon cancer causing the weakness of the affected viscus. (Am Surg 2012;78:E515.) Patients with a ruptured stercoral ulcer will have peritoneal signs and an acute abdomen; later complications will evolve into septic shock. (G Chir 2011;32[8-9]:368.) Differentials for these presentations include diverticulitis, appendicitis, and perforated peptic ulcer. Due to its rarity, clinicians often do not keep a ruptured stercoral ulcer in mind, but its high mortality rate if missed should warrant its permanent place on a list of differential diagnoses.
Clinicians should also be aware of how to identify and treat a stercoral ulcer once an exploratory laparotomy has begun. Ruptured stercoral ulcers will lead to evisceration of feces into the peritoneal cavity that will likely be widely noticeable. An ulcer will most likely be located at the antimesenteric border of the sigmoid colon and rectosigmoid junction, with feces present at the opening. (Am Surg 2012;78:E515.) The patient may also have evident megacolon leading up to the location of the ulcer. (South Med J 2006;99:525.) The ruptured viscera must be resected and the abdomen properly irrigated to remove the remaining feces from the peritoneal cavity. Lastly, a colostomy must also be formed. (G Chir 2011;32[8-9]:368.)
The need for parenteral antibiotics must also be addressed because these patients have a high risk of mortality due to septic shock. (G Chir 2011;32[8-9]:368.) They should be assessed for SIRS criteria and qSOFA to maintain blood pressure and prevent organ failure. (Open Forum Infect Dis 2016;3:ofw010.)
Mr. Macias, Mr. Zhang, and Ms. Hughes are medical students at the University of Medicine and Health Sciences (UMHS) in St. Kitts. Dr. Khan is a graduate of UMHS. Dr. Jacome is a bariatric and general surgeon at the department of surgery at Doctors Hospital of Augusta in GA.