|Year : 2018 | Volume
| Issue : 3 | Page : 115-122
Spontaneous pneumoperitoneum in pediatric patients: Dilemmas in Management
Department of Paediatric Surgery, SMS Medical College, Jaipur, Rajasthan, India
|Date of Web Publication||4-Jul-2018|
Dr. Rahul Gupta
Department of Paediatric Surgery, Kota Medical College, Kota, Rajasthan
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Context: Pneumoperitoneum is typically a surgical emergency, particularly in neonates. However, pneumoperitoneum can rarely present without gastrointestinal perforation which is known as spontaneous pneumoperitoneum.
Aims: This study aims to analyze the outcome of pediatric patients with spontaneous pneumoperitoneum and describe our experience.
Settings and Design: A retrospective study performed from January 2014 to May 2017.
Materials and Methods: The study included all pediatric patients admitted in a tertiary care institute.
Results: There were 9 patients with 5 males and 4 females, out of which 7 were neonates. At presentation, respiratory distress was a common complaint (8/9). 5 out of all patients developed abdominal distension. Associated malformations were seen in 5 patients. Pneumoperitoneum was preceded by mechanical ventilation in 5 patients. Abdominal examination revealed soft distension with relaxed abdominal wall in 7, while marked distension was present in 2 cases. Features suggestive of peritonitis were absent in all the patients. Abdominal radiographs revealed free air in all, while, radiographic evidence of pneumothorax was seen in 2 patients. Conservative management without any operative intervention was performed in 3 patients with favorable outcome. Laparotomy was performed in 1 patient; negative for any perforation and outcome was unfavorable. In 5 patients, abdominocentesis was performed followed by abdominal drain placement. No patient had any evidence of leakage of intestinal contents from gastrointestinal tract after insertion of abdominal drain. Favorable outcome was present in 5 patients. Out of 4 cases with unfavorable outcome, 3 patients were having esophageal atresia.
Conclusions: A high index of suspicion for spontaneous pneumoperitoneum must be present when dealing with pediatric patients, especially neonates with pneumoperitoneum and without clinical signs of peritonitis. A comprehensive clinical evaluation with sepsis screen must be carried out to supplement the diagnosis. Pneumoperitoneum in pediatric patients, especially neonates, is not always an absolute indication for surgery.
Keywords: Associated malformations, neonate, newborn, outcome, spontaneous pneumoperitoneum
|How to cite this article:|
Gupta R. Spontaneous pneumoperitoneum in pediatric patients: Dilemmas in Management. J Indian Assoc Pediatr Surg 2018;23:115-22
|How to cite this URL:|
Gupta R. Spontaneous pneumoperitoneum in pediatric patients: Dilemmas in Management. J Indian Assoc Pediatr Surg [serial online] 2018 [cited 2018 Jul 21];23:115-22. Available from: http://www.jiaps.com/text.asp?2018/23/3/115/235903
| Introduction|| |
Pneumoperitoneum is the presence of intra-peritoneal free gas, seen radiologically as air under the domes of diaphragm. In most of the patients, pathology is gastrointestinal perforation and is typically a surgical emergency. The source of air is usually from the perforation of the hollow viscus. However, pneumoperitoneum can rarely present without any gastrointestinal perforation.,,, There are few reports in the literature, where neonates, particularly premature newborns were explored after being diagnosed with pneumoperitoneum, and no definite abdominal cause of pneumoperitoneum (perforation/ischemic bowel, etc.) could be found., This condition has been called nonsurgical, asymptomatic, benign, misleading, spontaneous, or idiopathic pneumoperitoneum and sometimes called as continuous positive airway pressure (CPAP) belly syndrome.,,, It can improve without performing exploratory laparotomy. The management of the condition poses dilemma for the treating surgeon regarding surgical management of the neonate. The author observed series of cases of spontaneous pneumoperitoneum and is sharing his experience with mini review of pertinent literature.
Aims and objectives
This study aims to analyze the outcome of pediatric patients with spontaneous pneumoperitoneum and describes our experience.
| Materials and Methods|| |
A retrospective study was performed from January 2014 to May 2017. The study included all pediatric patients with spontaneous pneumoperitoneum admitted to our tertiary care institute. The clinical, operative records, and other details of these patients were analyzed along with associated malformations. Charts were reviewed according to age at presentation, sex, chief complaints, clinical findings, investigations undertaken, management (operative procedure/conservative), and outcomes.
| Results|| |
Clinical records revealed 9 pediatric patients with spontaneous pneumoperitoneum. The details of the patients are shown in [Table 1]. There were 5 males and 4 females; age ranged from newborn to 22 months. There were 7 neonates, 1 infant (60 days), and 1 with late presentation (22 months). Out of these 7 neonates, 5 were preterm babies. There were 2 neonates who presented shortly after birth (newborn period). Out of 9 patients, 8 were admitted in the hospital with features of respiratory distress (dyspnea and tachyapnea), 4 with fever (<101°F), while 1 had diarrhea at presentation. Only 5 patients had abdominal distension at the time of presentation, while in the remaining four cases, abdominal distension surfaced latter. Delayed passage of meconium was seen in 2 patients, out of which one was a known case of Hirschsprung's disease who presented after completion of the definitive treatment (Modified Martin's Duhamel procedure). Previous constipation was present in one patient. Associated malformations were seen in 5 patients; out of which 3 patients were Esophageal atresia (EA) type 3b (Vogt classification or EA with distal tracheoesophageal fistula [TEF]) as seen in [Figure 1], one was operated for right congenital diaphragmatic hernia (CDH) with associated malrotation and patent vitellointestinal duct and one with Hirschsprung's disease (as described above). Presentation of spontaneous pneumoperitoneum was preceded by mechanical ventilation in 5 out of 9 patients; AMBU (Artificial Manual Breathing Unit) ventilation in 1, CPAP in 1, synchronized intermittent mandatory ventilation in 1 and pressure support in 3 cases. Five patients were hemodynamically stable at presentation, while poor general condition with hemodynamic instability was present in 4; out of the four patients, one was having sclerema at presentation. Abdominal examination revealed soft distension with the relaxed abdominal wall in 7 patients, while marked abdominal distension was present in 2 cases. Signs such as muscle stiffness, guarding, abdominal wall edema, and induration of skin suggestive of peritonitis were absent in all the patients.
|Table 1: Clinical details, investigations undertaken, management and outcomes of patients with spontaneous pneumoperitoneum|
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|Figure 1: Bed-side radiograph (left) of intubated neonate with esophageal atresia with red rubber catheter (curved arrow) in situ revealing pneumoperitoneum (white arrow) and pneumoscrotum (small white arrow); clinical images (inset image at bottom) showing distended abdomen with pneumoscrotum (brilliantly transilluminant); clinical image of the same neonate (inset image at top) showing abdominal drain in situ with air bubble formation (other end in saline) with every cycle of the ventilation|
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Pneumoscrotum was seen in one patient of EA. Pneumoscrotum was brilliantly transilluminant (even without the use of torch), with shiny overlying skin [Figure 1] along with marked abdominal distension. It was soft to touch, easily reducible with characteristic refilling with air.
Abdominal radiographs revealed free air in all the patients in the study [Figure 2]. Radiographic evidence of pneumothorax was seen in 2 patients; in one patient (CDH), it was simultaneously present [Figure 2], while in other patient pneumothorax was evident after resolution of pneumoperitoneum [Figure 2]. C-reactive protein (CRP) was negative in 5 patients and positive in 1 patient (EA type 3b having sclerema and sepsis). CRP could not be estimated in 3 cases. Ultrasound was performed in all except 2 patients with EA who succumbed before primary repair could be contemplated. Ultrasound examination did not suggest any perforation or visceral pathology, apart from the presence of pneumoperitoneum.
|Figure 2: Radiographs showing: Free air (red arrow) under right dome of diaphragm (A1), resolution of pneumoperitoneum after conservative management (A2); Infant with congenital diaphragmatic hernia (B1) revealing pneumoperitoneum (yellow arrow) with pneumomediastinum (green arrow); pneumothorax with pneumoperitoneum (white arrow) is seen along with abdominal drain in situ (B2); gradual resolution of pneumothorax and pneumoperitoneum (B3); free air (red arrows) on right side (C1) and pneumothorax (yellow arrow) appearing after resolution of pneumoperitoneum (C2 and C3); neonate with abdominal distension (D1), after resolution of pneumoperitoneum (D2)|
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Enteral feeds were stopped and parenteral nutrition was initiated in all patients. Antibiotics with broad-spectrum coverage were given in all patients. All patients were closely observed for any development of signs suggestive of peritonitis.
Conservative management without any operative intervention was performed in 3 patients and all of these had favorable outcome. Laparotomy was performed in 1 patient; negative for any perforation and outcome was unfavorable. In 5 patients, abdominocentesis was performed followed by abdominal drain placement. No patient had any evidence of leakage of intestinal contents from gastrointestinal tract after insertion of abdominal drain [Figure 1] and [Figure 2]. Out of the five patients, right tube thoracostomy was performed in two patients. Primary repair of EA could be performed in 1 patient, while the other 2 cases succumbed and had unfavorable outcome before primary repair could be performed. Favorable outcome was present in 5 patients. Out of 4 cases with unfavorable outcome, 3 patients were having EA; the other patient had Laparotomy which turned out to be negative for any perforation. Time duration for resolution of pneumoperitoneum ranged from 48 h to 10 days in patients with favorable outcome. Associated cardiac anomalies were implicated as the cause for unfavorable outcome in 2 cases, severe sepsis in one and Sclerema and sepsis in other patient in the study. The duration of hospital stay in patients with favorable outcome ranged from 5 to 14 days. Follow-up after discharge was done for 3 months to 3 years and no recurrence of the pneumoperitoneum was seen and all 5 patients were doing well.
| Discussion|| |
Pneumoperitoneum is diagnosed by an erect plain film of the abdomen, with air beneath the domes of diaphragm. In the neonates, the outline of the falciform ligament of the liver against the radiolucency of free abdominal air may be seen (supine view); the oval central abdominal translucency corresponds to a large bubble of free air under the abdominal wall and is known as football sign. On the lateral supine view, a semilunar collection of air anterior to the abdominal viscera may be noted.
Usually, pneumoperitoneum is because of an abdominal pathology and necrotizing enterocolitis is the most common cause of pneumoperitoneum in a neonate. Conditions resulting in perforation of the gastrointestinal tract and presenting as pneumoperitoneum are gastrointestinal obstruction, atresias, volvulus, meconium ileus, Hirschsprung's disease, and iatrogenic injury. It manifests with peritonitis and sepsis. The clinical findings are tense abdominal distension, shiny redness, and induration of abdominal wall, tenderness, muscle stiffness, guarding, shifting dullness, and absent (decreased) bowel sounds. In addition, systemic features such as fever and toxemia are present. Thus it is categorized as surgical pneumoperitoneum. An urgent laparotomy is mandatory to improve survival.,
Pneumoperitoneum in a newborn with a normal abdominal examination and without peritonitis is extremely rare and is known as nonsurgical or spontaneous pneumoperitoneum.,,, In a large series of neonatal pneumoperitoneum, no abdominal etiology could be identified in 7.8% cases. In our study, 77.78% (7/9) patients were neonates and 28.57% (2/9) presented in the newborn period which was similar to other study. Thus, neonates have high predilection for spontaneous pneumoperitoneum., Although the condition was seen more common in males in our study and also recent series  the cause of such predilection is not clear. Associated malformations were seen in 55.56% patients in our study; EA type 3b being the most common (3), followed by CDH and Hirschsprung's disease, one each.
Respiratory distress was the most common presentation (88.89%) in our study. Abdominal distension was present in 55.56% (5/9) patients at presentation, although all cases developed abdominal distension during hospitalization. Diarrhea along with abdominal distension was the chief complaints in one case with Hirschsprung's disease.
The origin of spontaneous pneumoperitoneum has been postulated to be air leak from the lungs. The condition is comparatively more in premature babies (55.56% in our study) owing to the underdeveloped alveoli and their predisposition to rupture after rigorous resuscitation and ventilation.,, Spontaneous pneumoperitoneum has been reported in premature infants who were on mechanical ventilation for pulmonary or cardiac diseases., Positive pressure or mechanical ventilation leads to an increased pressure gradient between the alveoli and the pulmonary interstitium. In combination with an underlying lung abnormality such as surfactant deficiency or prematurity (renders the alveoli more fragile) resulting in alveolar rupture, either leading to pneumothorax or escape of air through the tiny openings of alveoli into the perivascular space. Air dissects along the perivascular sheaths towards the hilum and leaks into loose connective tissue spaces of the mediastinum which leads to pneumomediastinum. This is followed by extension of free air under tension in the mediastinum along the vascular planes through the normal diaphragmatic openings (along the aorta and esophagus) or retrograde path through the pulmonary lymphatics, leading to free air in the retroperitoneum and then to peritoneal cavity. The air can also pass into the peritoneal cavity through CDH or from a pleuroperitoneal fistula. This is more common with high and prolonged airway pressure during mechanical ventilation or CPAP.,,,, In our study, the condition was preceded by mechanical ventilation in 55.56% cases; pressure support ventilation was most commonly seen with 33.33% (3/9) patients. CPAP belly syndrome was evident in one patient. Inpatient of Hirschsprung's disease, the origin of free air could not be explained. The condition has also been observed in patients after cardiopulmonary resuscitation, gynecological procedures, and trauma.
Massive right-sided pneumothorax with retroperitoneal extension followed by passage of free air from retroperitoneum to peritoneal space was also observed by Bakal et al. The presence of pneumothorax  or pneumomediastinum immediately before or simultaneously with pneumoperitoneum is a pointer toward spontaneous pneumoperitoneum, which was clearly evident seen in one of our case. In one patient pneumothorax became obvious on plain radiograph after resolution of pneumoperitoneum. Isolated neonatal pneumomediastinum (2.5/1000 live births) has been reported with use of mechanical ventilation in the setting of premature lungs, respiratory distress syndrome, and pneumonia.
The presence of pneumoscrotum in one of our case could be explained by the patent processus vaginalis which may be present in 95% male neonates., Free air in the peritoneal cavity tracks into the scrotum resulting in its marked scrotal distension and brilliant transillumination. It must be differentiated from hydrocele of tunica vaginalis and lymphangioma of inguinoscrotal region.
The differential diagnoses of spontaneous pneumoperitoneum are extraperitoneal air accumulation, mediastinal emphysema, and pneumatosis cystoides intestinalis in neonatal age group. Pneumatosis cystoides intestinalis may associated with free air under domes of diaphragm, but it has characteristic circular translucent areas on the intestinal wall.
The diagnosis of spontaneous pneumoperitoneum with radiographs showing free air under domes of diaphragm is made only after ruling out abdominal cause of air leak or visceral pathology. The clinical features include soft abdominal distension, the absence of signs of peritonitis such as tenderness, muscle stiffness, guarding, abdominal wall edema, redness and induration of abdominal wall. The absence of systemic features like fever and toxemia in association with unremarkable abdomen are suggestive of spontaneous pneumoperitoneum. However, according to our study, the presence of systemic symptoms such as fever, respiratory distress, and laboratory values such as leukocytosis, falling platelets, and raised CRP may be due to respiratory tract infection, septicemia or due to complications related to associated malformations (EA). Appropriate history and repeated clinical evaluation with abdominal radiographs are performed.
Management consists of discontinuing the oral feeds and optimization of the clinical condition (intravenous fluids, parenteral nutrition, broad-spectrum antibiotics, and intensive care) along with close observation for signs suggestive of peritonitis., Conservative management, avoiding a laparotomy is the treatment of choice.,, In 33.33% (3/9) patients, no operative intervention was performed and results were favorable. Laparotomy was contemplated in one patient due to suspected perforation of hollow viscus, owing to falling platelet counts (147,000/mm 3) and leukocytosis (TLC 23,100/mm 3) in spite of the negative CRP and presence of soft abdominal distension.
In 55.56% (5/9) patients, abdominocentesis was performed to diagnose the contents of leak and ruling out leakage of intestinal contents from gastrointestinal tract or presence of peritoneal fluid. Abdominocentesis is ideally performed under ultrasound guidance. It helps in differentiating surgical from spontaneous pneumoperitoneum, especially in neonates because peritoneal signs may not be characteristic due to laxity of abdominal wall muscles. In 2 patients, additionally, it helped to relieve the marked abdominal distension which was causing respiratory embarrassment. Abdominocentesis was followed by abdominal drain placement; the presence of free air was confirmed.
Right tube thoracostomy was performed in 28.57% (2/9) patients, owing to the presence of pneumothorax, confirmed radiologically in one and clinically in the other patient. Resolution of the free air in the retroperitoneal space secondary to massive tension pneumothorax in a neonate was observed after performing tube thoracostomy. In one neonate, pneumothorax was seen after resolution of pneumoperitoneum; close observation was done as she was stable with no respiratory distress. These pneumothoraces spontaneously resolve in few days.
After following the above-mentioned treatment, the abdominal free air must decrease and surgical pneumoperitoneum is excluded from the study. However, in one of our patient, there was no improvement in the amount of free air after placement of the abdominal drain. With every cycle of the ventilation, there was increment in the free air which was confirmed by bubbling at other end of the drain which was immersed in normal saline [Figure 1]. A right tube thoracostomy helped in resolution of the free air. Complete resolution of pneumoperitoneum [Figure 1] may take 48 h to 10 days, which was similar finding (2–8 days) in another study.
The indications for surgical intervention in pneumoperitoneum are the features of peritonitis, pain, and cardiovascular instability, supplemented by leukocytosis, evidence of leakage from gastrointestinal tract, and failure of conservative management.,
Author recommends that neonates have high predilection for spontaneous pneumoperitoneum. Any pediatric patient, particularly neonate with free air under domes of diaphragm with the absence of signs of peritonitis and no systemic symptoms, diagnosis of spontaneous pneumoperitoneum must be considered. In these patients, conservative treatment is given along with close monitoring and repeated abdominal examination is performed for development of any sign of peritonitis. Ultrasound examination should be performed to rule out visceral pathology, ischemia, or perforation. Neonates with congenital malformations presenting with pneumoperitoneum and absence of abdominal signs of peritonitis, but with features of sepsis like fever or leukocytosis or positive CRP, clinical evaluation of the lungs along with chest radiographs (PA view) are performed to evaluate for pneumonitis.
In suspicious cases, abdominocentesis must be performed to ascertain the peritoneal contents and confirming the presence of free air. Second, it will help in better assessment of abdomen and ruling out peritonitis. Third, it would relieve the respiratory embarrassment due to splinting of diaphragm and improve the cardiopulmonary function. Fourth, it will prevent occurrence of abdominal compartment syndrome due to tension pneumoperitoneum. Furthermore, abdominal drain placement is done in cases with marked abdominal distension causing respiratory embarrassment, which is not relieved by abdominocentesis. It also helps in continuous evaluation of the peritoneal contents. A high index of suspicion for pneumothorax or pneumomediastinum must be present along with low threshold for performing tube thoracostomy, especially in patients with associated malformations like EA and in postoperative period. Repeated radiographic assessment for evaluation of pneumoperitoneum and pneumothorax is contemplated till there is complete resolution of symptoms and disappearance of radiographic signs.
| Conclusions|| |
In any pediatric patient, especially neonate with radiographs showing pneumoperitoneum, a comprehensive clinical evaluation: (a) repeated abdominal examination for signs of peritonitis and (b) pulmonary signs, especially for the presence of pneumothorax are performed. Sepsis screen and blood parameters (including complete blood count) must be carried out to supplement the diagnosis. In the presence of sepsis or marked abdominal distension and suspicious cases, ultrasound examination for ruling out perforation/visceral pathology and abdominocentesis and/or abdominal drain placement should be contemplated to rule out perforation and to direct further management. Unnecessary emergency laparotomy on an otherwise normal neonate with an unexplained pneumoperitoneum is to be condemned. The presence of pneumoperitoneum in pediatric patients, especially neonates, is not always an absolute indication for surgery.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
I am sincerely thankful to faculty, residents and nursing staff of Department of Paediatric Surgery, SMS Medical College, Jaipur, for helping me in this endeavor.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]