APACHE II Score: Acute Physiology and Chronic Health Evaluation II Score; APRV: Airway Pressure Release Ventilation; CHDF: Continuous Hemodiafiltration; CT: Computed Tomography; DCS: Damage Control Surgery; DKA: Diabetic Ketoacidosis; ECMO: Extracorporeal Membrane Oxygenation; ICU: Intensive Care Unit; NOMI: Non-occlusive Mesenteric Ischemia; PMMA: Poly-methyl Methacrylate; SOFA Score: Sequential Organ Failure Assessment Score; V-A: Veno- Arterial; V-V: Veno- Venous

Nonocclusive mesenteric ischemia (NOMI) is a condition characterized by intestinal ischemia without any obstruction of the mesenteric artery or vein. NOMI requires extensive intestinal resection, and the outcome is very poor due to complicating organ failure1). We report herein a successful case of ECMO support for postoperative cardiac arrest associated with NOMI that occurred during pregnancy.

Case: 34-year-old woman

Past history: The patient had no particular past history except for glycosuria identified during her first pregnancy without any follow-up.

Present history: She was in her second pregnancy with 6weeks of gestation. She carried to our hospital with abdominal pain and vomiting that persisted for 2 days. She did not exhibit any obstetric abnormalities. Soon after admission, she fell into shock and unconsciousness.

Present symptoms: Glasgow Coma Scale, E4V4M6; blood pressure, 84/43 mmHg; heart rate, 130/min; respiratory rate, 37/min; body temperature, 36.1°C; marked peripheral coldness, abdominal distention and tenderness with muscular defense; Acute physiology and chronic health evaluation II score (APACHE II score), 45; Sequential organ failure assessment score (SOFA score), 15.

Laboratory findings upon hospitalization (Table 1): Blood biochemistry results revealed hyperlactatemia. Marked metabolic acidosis and electrolyte abnormality with excessively high levels of interleukin-6, procalcitonin and endotoxin. As a result, abnormally high blood glucose and a marked increase in total ketone bodies led to a diagnosis of diabetic ketoacidosis (DKA).

Table 1: Laboratory findings upon hospitalization.

Clinical course after intensive care unit (ICU) admission: Since contrast-enhanced computed tomography (CT) scanning identified an extensive filling defect area in the intestinal tract wall with a large volume of portal venous gas (Figure 1), an emergency laparotomy was performed. Ischemia and necrosis were observed in most parts of the small intestine and ascending colon. Minimum essential surgery (subtotal resection of small intestine and right hemicolectomy) was performed due to unstable circulatory/respiratory dynamics, and the patient returned to the ICU with open abdominal management. The duration of surgery was one hour and 36 minutes.

Figure 1:Contrast-enhanced CT of the abdomen CT shows portal venous gas and intestinal dilatation without enhancement.

Since subsequent pathological examination demonstrated no apparent occlusive lesions in the mesenteric artery or vein, a diagnosis of NOMI was established. Close examinations for autoimmune diseases, vasculitis, and thrombotic diathesis were all negative in relevant blood tests.

Postoperative course (Figure 2): Chest-X-ray upon return to the ICU demonstrated a marked decrease in radiolucency. P/F ratio was 35 mmHg despite the high positive pressure ventilation at FIO2 of 1.0 in the airway pressure release ventilation (APRV) mode. Therefore, we decided to implement V-V ECMO.

Figure 2:Clinical course while ECMO management.

However, exacerbation of hemodynamics induced by progressive respiratory failure and postoperative stress led to cardiac arrest during cannulation. V-A ECMO was hastily introduced in place of V-V ECMO. A 25-Fr Biomedicus cannula™ (Medtronic, Minneapolis, United States of America) was placed in the right internal jugular vein as a venous (drainage) cannula; while a 17-Fr Biomedicus cannula™ (Medtronic, Minneapolis, United States of America) was placed in the right femoral artery as an arterial (return) cannula. A BIOCUBE6000™ membrane oxygenator (Nipro, Osaka, Japan) and a Rota flow™ centrifugal pump (Maquet, Rastatt, Germany) were used. Since drainage failure was happened frequently, careful infusion of crystalloid or blood transfusion with monitoring hemodynamic parameters was performed to ensure the required blood flow. In addition, continuous hemodiafiltration (CHDF) using polymethyl methacrylate (PMMA) membrane hemo-filter for renal replacement therapy and cytokine modulation was performed concomitantly, and administration of hydrocortisone for relative adrenal insufficiency and appropriate antibiotics were also initiated. By day 4, these treatments enabled to wean off V-A ECMO although respiratory failure has not recovered yet. Furthermore, compartment syndrome of right lower limb developed and surgical fasciotomy was required despite supplemental blood flow with the bypass circuit to prevent ischemia. Accordingly, V-A ECMO was switched to V-V ECMO on day 4. On day 5, colostomy was performed, with concomitant resection of the necrotized uterus with embryo and left ovary. Abdominal wall was closed at this time. With subsequent improvement of oxygenation, V-V ECMO was terminated on day 9. On day 14, irrigation drainage and colostomy were performed to cope with anastomotic leak. Gauze packing was placed for retroperitoneal bleeding on day 24. Furthermore, since extensive necrosis and infection were observed in the right lower extremity, above knee amputation was performed on day 26. Her general condition has been gradually stabilized thereafter, and mechanical ventilation was terminated on day 35. She was discharged from the ICU on day 78.

Finally, we performed closure of the colostomy and anastomosis of the residual duodenum and colon on Day152. She was discharged to her home without any neurologic impairments on Day262. She is currently on outpatient care with continued home parenteral nutrition due to short bowel syndrome.

This is a case of successful resection of necrotized intestine and intensive care (including ECMO) in NOMI with multiple organ failure. NOMI is known as a lethal condition triggered by shock or heart failure in high-risk patients with heart disease, on chronic maintenance dialysis, or at an advanced age [1,2]. In the present case, the patient had no such risk factors, but developed NOMI in her early pregnancy through a rapid clinical course. Although the mechanism of developing NOMI in this patient could not be clarified by pathological findings, glycosuria identified during her first pregnancy and development of DKA on ICU admission suggest possible exacerbation of glucose tolerance and electrolyte abnormality with hyperemesis gravidarum-induced severe dehydration led to NOMI. To date, several cases of DKA complicating with NOMI have been reported in Japan. Our literature search was unable to identify any reports describing an association between pregnancy and development of NOMI.

Most cases of NOMI bring about intestinal necrosis and therefore require extensive intestinal resection for treatment. In such cases, the outcome is extremely poor, as indicated by mortality rates of approximately 50-80% [1,3], which reaches 75% in the presence of portal venous gas [4]. In the present case, extensive intestinal necrosis and portal venous gas were noted with preoperative complications such as hyperlactatemia and severe metabolic acidosis. The patient fell into cardiac arrest due to severe respiratory/circulatory failure after surgery and was expected poor prognosis based on an APACHE II score of 45 (corresponding to an estimated mortality rate of 97.8%).

In the treatment of trauma or abdominal emergencies, damage control surgery (DCS) is recommended in critically ill patients with the deadly triad (hypothermia, acidosis, and coagulopathy) [5,6]. Although this patient had not fell into deadly triad before surgery, development to it during surgery was anticipated. Therefore, the first surgery of this patient was limited to resection of the apparently necrotized part of the intestine as DCS. Consequently, fatal collapse was occurred at not operation room but ICU and ECMO was implemented very quickly by intensivist. If cardiac arrest was happened during surgery, the duration of cardiac arrest might be longer. In addition, indication of ECMO in such cases depends on the result of source control. As the surgery had been finished, the decision to introduce ECMO was easier. In summary, DCS and quick implement of ECMO led to the survival of this patient.

Successful survival of a patient developing cardiac arrest associated with nonocclusive mesenteric ischemia during pregnancy was achieved by damage control surgery and quick introduction of ECMO.