INTRODUCTION
Nearly two-thirds of patients admitted to the intensive care unit (ICU) after cardiac arrest (CA) who subsequently experience return of spontaneous circulation (ROSC) develop post-resuscitation syndrome due to systemic ischemia-reperfusion. The gastrointestinal tract can be damaged by ischemia during CA, reperfusion during ROSC, or shock after ROSC. Ischemia can cause damage ranging from cellular dysfunction to transmural necrosis without occlusion of the major mesenteric arteries, a condition known as nonocclusive mesenteric ischemia (NOMI) [1]. In adults, 0.68% to 2.5% of patients successfully resuscitated from out-of-hospital CA have been reported to develop NOMI [1,2].
Reports of NOMI in children are limited; however, the reported pediatric NOMI cases are associated with underlying conditions including burns, diabetic ketoacidosis, hypoplastic left heart syndrome, familial dysautonomia, Addison disease, situs inversus, limbic encephalitis, and/or severe neurodevelopmental disorders [3–12]. Here, we report the first case of pediatric NOMI after ROSC.
CASE REPORT
A healthy 16-month-old boy (height, 72 cm; weight, 9.2 kg) presented to Hyogo Prefectural Amagasaki General Medical Center (Amagasaki, Japan) with CA resulting from food aspiration. The family attempted to save him by patting his back and holding him upside down; however, these measures were ineffective. After 15 minutes, emergency services were contacted, who initiated chest compressions. Upon the ambulance’s arrival at 23 minutes, the initial electrocardiogram waveform indicated asystole, and cardiopulmonary resuscitation was continued. The patient was transported in an ambulance with paramedics on board. After 44 minutes, the electrocardiogram waveform still indicated asystole, and a rapid response car carrying doctors, nurses, and paramedics joined the ambulance on the way to the hospital. After 47 minutes, the first dose of epinephrine was administered, and the patient was intubated. Multiple pieces of baked potato were removed from the trachea using an endotracheal suction tube. The patient was then admitted to our hospital. After 10 doses of adrenaline, ROSC was confirmed 95 minutes after onset.
Subsequently, a continuous intravenous adrenaline infusion was initiated, the patient was admitted to the pediatric ICU (PICU), and brain-protection treatment was initiated. Upon admission to the PICU, the patient's arterial blood gases showed severe acidosis, with a pH of 6.720, low PCO2 of 28.9 mmHg, high PO2 of 248.0 mmHg, low HCO3 of 3.7 mmoL/L, very low base excess (BE) of –31.7 mmoL/L, and a high lactate level of 18.0 mmoL/L.
The body temperature was 34 °C upon admission and remained stable. Inotropes were administered at high doses for persistent hypotensive shock. The patient was temporarily stabilized with a combination of epinephrine (dose, 0.2 μg/kg/min) and norepinephrine (dose, 0.1 μg/kg/min). After 24 hours, epinephrine was reduced to 0.05 μg/kg/min, and norepinephrine was maintained at 0.1 μg/kg/min. The patient's vital signs improved; however, abdominal distension and a high intravesical pressure of 10 mmHg were observed. Although decompression through the gastric tube and enema were attempted, they had little effect. The gastric contents were small and brown, with no observed defecation. Abdominal sonography did not reveal ascites or fluid accumulation in the intestinal tract. The arterial blood gas levels were as follows: pH, 7.297; PCO2, 44.6 mmHg; HCO3, 20.6 mmoL/L; BE, –4.7 mmoL/L; and lactate, 3.2 mmoL/L.
On hospital day 3, 40 hours after onset, blood pressure decreased again, the abdomen became distended, and intravesical pressure increased to 18 mmHg, for which epinephrine and norepinephrine were increased to 0.3 and 0.3 μg/kg/min, respectively. Hypotensive shock was unresponsive to increased vasoactive drug doses and lactate levels remained elevated. The abdomen continued to expand. Fluid balance since admission was +1,403 mL (152 mL/kg). Scrotal and lower extremity edema worsened. The arterial blood gases were pH, 7.253; PCO2, 43.7 mmHg; HCO3, 18.1 mmoL/L; BE, –7.9 mmoL/L; lactate, 4.4 mmoL/L; and C-reactive protein, 14 mg/dL. The Pediatric Sequential Organ Failure Assessment score was 15.
Abdominal contrast-enhanced computed tomography revealed marked dilatation and pneumatosis of the small bowel. Therefore, NOMI was suspected (Fig. 1). At the time of deterioration, the pupils were constricted, and electroencephalogram revealed burst suppression. However, neurological outcomes were uncertain.
Laparotomy revealed a small bowel discoloration, indicating necrosis (Fig. 2). The necrosis was widespread throughout the intestinal tract. The jejunal artery region exhibited the most severe necrosis, while the ileocecal and splenic flexure areas, which are anatomically prone to ischemia, showed relatively little necrosis [13]. Consequently, a partial resection of the small bowel and a loop ileostomy were performed. Of the total small bowel length of 260 cm, 140 cm remained. The operation lasted 2 hours and 20 minutes, and no blood transfusion was required. Histopathological examination revealed patchy mucosal necrosis, diffuse transmural hemorrhage, and congestion. No arterial or venous thrombi were observed in the resected specimens (Fig. 3).
Despite initial concerns about intestinal edema based on physical findings, intraoperative findings revealed no significant findings. Additionally, pathological findings confirmed the absence of microvascular obstruction due to edema.
Circulation was stabilized, the dose of epinephrine was reduced to 0.2 μg/kg/min, and norepinephrine was reduced to 0.05 μg/kg/min on the day after surgery. Inotropes were discontinued on the 3rd postoperative day. After surgery, body temperature was increased by 0.5 °C every 12 hours.
A tracheotomy was performed on hospital day 18, and the patient was transferred to the general ward on hospital day 32. Creatine levels, which had deteriorated to a maximum of 1.61 mg/dL due to acute kidney injury, returned to a normal level (<0.2 mg/dL). Enteral feeding initiation led to the improvement of colonic obstruction with medical treatment, and stoma closure was performed on hospital day 44. Subsequently, the patient was discharged. Neurologically, the child scored 4 on the Pediatric Cerebral Performance Category scale, remaining severely handicapped but breathing spontaneously and was successfully weaned from daytime ventilation.
DISCUSSION
This report indicates that, similar to reports on adults, toddlers may develop NOMI after ROSC following CA. A review of previous NOMI cases in children revealed that all nine reported pediatric cases underwent surgery, and four were diagnosed through computed tomography scans [3–12]. The initial clinical manifestation of NOMI is typically acute abdominal pain accompanied by pain and muscle guarding. However, in a sedated state following resuscitation, a diagnosis based solely on a physical examination can be challenging. Abdominal distension and intravesical pressure were monitored from the second day of admission, with the latter aiding in the identification of abdominal findings. Laboratory data can also assist in diagnosis. A report on NOMI after CA in adults revealed abnormal pH, lactate, and BE values at the time of admission compared to those in the group without NOMI [2]. Abnormal blood gas levels were also reported at the time of admission. The aforementioned adult study reported that low blood flow for longer than 17 minutes and an inotropic score higher than 7 μg/kg/min were associated with NOMI [1]. These findings also were true in the present case. It has been reported that hypothermia is associated with NOMI [14]. However, when resuscitation time is prolonged, as in the present case, NOMI may be an unavoidable complication, regardless of intensive care management.
For methods of surgical intervention and subsequent treatment courses, four of the nine pediatric cases reported to date required multiple surgeries and three required stoma creation [3–12]. Surgery under compromised circulation conditions is hazardous, and the duration of surgery should be minimized. In contrast, the removal of necrotic bowel tissue can improve circulation. In our patient, necrosis was widespread throughout the intestinal tract. If the entire intestinal tract with poor color had been removed, the remaining small intestine would have been extremely short; however, if necrotic bowel tissue remained in place, a second surgery would likely be necessary. We considered these factors to determine the extent of bowel resection needed. A stoma was inserted to observe the progress, allowing the patient to survive with minimal bowel resection. Although the mortality rate of NOMI is high in adults, all nine reported pediatric patients were discharged. This suggests that children with NOMI are more likely to survive than adults.
In summary, NOMI can occur in children during hypothermia after ROSC following CA. While NOMI is uncommon in children, appropriate surgery can be lifesaving.