in Infancy and Childhood
Wojtek J. Górecki
Children are not small adults.
The well-known phrase that children are not small adults is eminently applicable to pediatric abdominal emergencies, not only because of differences in physiology and metabolism, but also because of a different clinical spectrum of ab- dominal emergencies, their presentation and management. This chapter focuses on abdominal surgical emergencies in infants and small children. Neonatal emergen- cies are omitted, as you are unlikely to encounter them unless you are a specialist pediatric surgeon.
The first principleto remember is that you are less likely to commit an error if you consider an atypical presentation of a common condition than a typical presentation of a rare condition. Translating this principle into clinical reality, a pediatric acute abdomen is intussusception in infancy or appendicitis in childhood – until proven otherwise.Another principleis that, much like with adults, watchful waiting is a prudent strategy in children.
General Approach to Pediatric Abdominal Pain
The philosophy of classifying the multiple etiologies of the acute abdomen into several well-defined clinical patterns,presented in > Chap.3,works for children as well. The major pitfalls in assessing the pediatric acute abdomen are timing, his- tory and abdominal palpation.
Children with abdominal pain present to the emergency room at varying stages of disease because the timing of presentation depends on the parents. Some parents delay, while others are over-sensitive and rush for a surgical consultation. As a general rule – as originally stated by Sir Zachary Cope – consider any abdominal pain lasting more than 6 hours as a potential surgical problem.
Younger children do not give you a history, but listen to the parents because they know their kids so well.A classical example is intussusception,where a descrip-
tion of the child’s behavior and a glance at the stool can point you to the diagnosis even before the physical examination.
The importance of gentleness during abdominal palpation cannot be over- emphasized.The majority of children with a sore tummy object to abdominal palpa- tion. Sometimes a toy provides a temporary distraction that will allow you to examine the abdomen,but it is pointless to persist if the child is antagonized.Instead of the usual “head-to-toe” sequence of the physical exam in adults, take advantage of a spell of sleep to sneak a warm gentle hand underneath the blanket to palpate the abdomen.
An infant who will not allow a gentle attempt even when held in his mother’s lap should be sedated, because sedation does not affect muscle guarding. Our preference is intranasal midazolam 0.1–0.2 mg/kg.
Examination of the scrotum is essential for two reasons. First, an acute condition in the right testicle,such as torsion,can present with pain in the right groin and iliac fossa. Secondly, perforated appendicitis occasionally presents with a painful scrotal swelling, because pus enters the patent processus vaginalis, causing acute funiculitis.
Rectal examination is best left to the end of physical examination,after looking at the throat and ears, and is not needed if there is a clear indication for laparotomy.
Clinical Patterns of Acute Abdomen in Kids (see also > Chap. 3)
The combination of acute abdominal pain and shock is rare in children, and should make you think of occult abdominal trauma with rupture of an enlarged solid organ or a tumor (e.g. ruptured Wilms’ tumor). Contrary to adults, urgent laparotomy is not always indicated.
Generalized peritonitisin children is most commonly due to appendicitis.
Do not try to elicit rebound tenderness,as you will lose the confidence and coopera- tion of your patient. (This applies to adults too!)
Localized peritonitisin the left lower quadrant can be due to acute constipa- tion, whereas right or left upper quadrant tenderness is commonly due to acute distension of the liver or spleen, respectively.
Intestinal obstructionin a virgin abdomen is caused by intussusception or appendicitis. One of ten children with complicated rotational anomalies of the midgut presents after the neonatal period. The critical concern with malrotation is midgut volvulus with acute bowel ischemia. This life-threatening condition carries the risk of rapid transmural intestinal necrosis. Your surgical intervention should be prompt because simple counter-clockwise detorsion of the bowel may save it.The two major pitfalls in pediatric small bowel obstruction are missing an incarcerated inguinal hernia and waiting too long with conservative management before surgery.
A wide spectrum of non-surgical conditions mimic abdominal emergencies.
Particularly in infants,any acute systemic disease may present with apathy,vomiting and stool abnormalities. Gastroenteritis is common in children and typically presents with acute abdominal complaints. The converse is also true. A child with an acute abdomen may present with a wide array of seemingly unrelated symptoms suggesting early meningitis, a neurological disorder or poisoning.
Specific Pediatric Emergencies
The relative incidence of the conditions in the different age groups is depicted
in > Fig. 32.1.
Acute Appendicitis (AA) (see also > Chap. 28)
AA is rare during the first year of life and is uncommon during the second.
Thereafter the incidence rises and peaks between ages 12 and 20. AA in infancy typically presents as generalized peritonitis due to perforation. The infant looks unwell, with fever, tachycardia and tachypnea. The abdomen is distended and generally tender with guarding. Diarrhea is more common than constipation.Pay attention to the useful “hunger sign”; we have not seen a hungry child who turned out to have AA.Consider AA in the second place on your list of differential diagnoses for an infant with an acute abdomen,and in the first three places in a child.The white cell count is normal in many cases of pediatric AA,but neutrophilia is more specific.
Admitting children with equivocal signs for observation is a safe option, as the chance of rupture under observation in a pediatric surgical ward is less than 1%
(oops – the Editors asked for no percentages…).
Fig. 32.1. Pediatric abdominal emergencies
A limited helical CT with rectal contrast has high accuracy in diagnosing AA in children, but clinical examination by an experienced pediatric surgeon is just as good. Even if the CT scan is positive, appendectomy is not indicated if the child improves clinically.
What is the role of laparoscopy in the doubtful case? While it offers the advan- tage of a diagnostic modality that can be immediately followed by appendectomy, it will subject some children to an unnecessary operation. If you can get the child into a CT scanner without general anesthesia, this should be your preferred choice instead of diagnostic laparoscopy.
The value of laparoscopic pediatric appendectomy remains controversial because there are no good data to suggest that it confers an advantage in postopera- tive recovery. However, it is a valid alternative to the open technique. The short dis- tances and thin abdominal wall of children allow a port-exteriorization append- ectomy,performed via two ports,where the appendix is exteriorized by pulling it out of the right iliac fossa port and then the entire appendectomy is performed outside the abdomen. Or the appendix can be pulled out of the umbilical port, and if you have a laparoscope with a working channel, you can perform a single port append- ectomy using the same technique. [Which would be equivalent to a conventional – no port – appendectomy through a 2-cm incision. – the Editors]
There is no point in culturing the peritoneal fluid in case of obvious AA because the results are predictable and antibiotics have usually been stopped by the time the culture results become available. Decide on the duration of postoperative antibiotics according to the degree of contamination/infection found in the perito- neal cavity (see > Chap. 12).
Intussusception
Telescoping of one portion of the intestine into another can turn a healthy baby into a critically ill patient within a few hours. It typically occurs between the ages of 5 and 7 months, and the etiology is idiopathic. In children older than 2 years, look for an underlying pathology, the most common being a Meckel’s diverticulum. Early intussusception is generally a benign condition, although it is a strangulating obstruction eventually leading to vascular compromise.Most cases start in the ileum as ileo-ileal intussusception and then progresses through the ileo-cecal valve to become ileo-colic intussusception.
The diagnosis is straightforward if the infant exhibits the classical clinical syndrome.A previously healthy infant suddenly starts to scream,pulls up its legs and perhaps clutches the abdomen. The pain is then relieved and the child may relax for a while only to have a similar bout 15–30 minutes later. This leaves the infant pale and ill. Vomiting and passing of “red currant jelly” stools is also characteristic,
although salmonellosis may show a similar clinical picture. Atypical presentations are common and lead to diagnostic errors. The infant may be fretful and restless without either pain or vomiting. Pallor and peripheral coolness due to vasocon- striction, lethargy and seizures may also confuse the picture.The crucial physical sign is palpation of an abdominal mass.The ultrasonographic findings of a “target sign” on cross section and “pseudo-kidney sign” in a longitudinal view are impor- tant adjuncts to the clinical diagnosis.
Children with diffuse peritonitis, perforation, progressive sepsis and possible gangrenous bowel should undergo an urgent laparotomy. Early intussusception without peritonitis is reduced non-operatively with pneumatic or hydrostatic pres- sure under radiographic or ultrasonic guidance.Water-soluble contrast is safer than barium in case of perforation. Reduction is successful in the majority of cases but requires close collaboration between surgeon and radiologist.
Operative reduction of an early intussusception: squeeze on the apex of the intussusception while the bowel is still within the abdomen so that the intus- suscepted segment begins to slide out.When the reduction reaches the region of the hepatic flexure it may become more difficult but after you eviscerate the proximal colon the reduction can be completed under direct vision.After achieving complete reduction remember to examine the entire bowel for a pathology serving as a lead point.If the intussusception is truly irreducible,or if the bowel has suffered a serious vascular compromise – resect it.
Meckel’s Diverticulum
Two-thirds of Meckel’s diverticula encountered by surgeons are incidental findings while the remaining one-third will present with a complication. The inci- dence of these complications is maximal during the first year of life and decreases thereafter so that more than two-thirds of all complications occur in the pediatric population. These complications include bowel obstruction (adhesive obstruction, volvulus or intussusception), complications of peptic ulceration in ectopic gastric mucosa (stricture, hemorrhage, or perforation), or acute inflammation (“second appendicitis”). There is also a distinct tendency for foreign bodies to penetrate and perforate a divetriculum. Littre’s inguinal hernia contains a strangulated Meckel’s diverticulum and, like Richter’s hernia, does not produce signs of intestinal ob- struction.
The treatment of a symptomatic diverticulum is resection. Diverticulectomy is possible if the base is wide and non-inflamed, but remember to check the base of the diverticulum and the adjacent ileal mucosa because the bleeding source may lie within it.If in doubt,or if there is any technical difficulty,resect the segment of ileum carrying the diverticulum.
What should you do with an incidentally found Meckel’s diverticulum? Con- sider the degree of peritoneal infection, the patient’s age and the shape of the diverticulum. On balance, the arguments against removing an asymptomatic Meckel’s diverticulum are a little stronger than those in favor, and the strength of the argument increases with the age of the patient. Thin-walled, wide-mouthed diverticula should be left alone.
Irreducible Inguinal Hernia
This emergency occurs primarily in boys during their first year of life. The fundamental difference between an irreducible inguinal hernia in an infant and an adult is that the former presents a danger to the viability of the testis, whereas with the latter the major concern is the potential for bowel ischemia. Neonates with symptoms lasting for more than 24 hours and with intestinal obstruction are at the greatest risk of testicular infarction.Necrosis of incarcerated bowel is extremely rare in pediatric hernias.
The diagnosis is straightforward because the baby cries and vomits and the parents have usually noticed a tender lump in the groin. The major differential diagnosis is with torsion of a maldescended testicle, acute inguinal lymphadenitis and a hydrocele of the cord. After making the diagnosis, sedate the infant and position him in a head-down position. In the majority of babies, this will result in spontaneous reduction within 1–2 hours. Let the tissue swelling subside for a day or two and book the child for an elective herniotomy on the next available opera- tive list.
The operation for irreducible inguinal hernia in an infant is fraught with danger and should be undertaken only by a surgeon with previous experience in pediatric surgery.The hernia sac is edematous and extremely fragile,and the ductus deferens is almost invisible. Simple herniotomy at the level of the neck of the sac is all that is required.Always make sure that the testicle is safely replaced into the lower part of the scrotum.In a female infant,a movable tender lump may be an irreducible ovary. The child may be almost asymptomatic yet require emergency herniotomy because of the risk of ovarian ischemia.
Testicular Torsion
The key to successful treatment of testicular torsion is speedy detorsion, within less than 6 hours of the onset of symptoms. The incidence of torsion rises sharply around age 12, with two of every three cases occurring between the ages of 12 and 18. Some boys with testicular torsion present with lower abdominal and
inguinal pain so you will miss the diagnosis if you fail to examine the scrotum.
No clinical sign or test is foolproof, and because the price of delay is loss of the testis, the common wisdom is to have a low threshold for exploring an “acute scrotum”.
If prompt surgery is not available, manual detorsion in a lateral direction under sedation or local anesthetic infiltration of the cord may restore testicular blood flow.The operative procedure is bilateral orchidopexy to protect the ipsilateral testicle from recurrence and to secure the contralateral one,as inadequate anatomic suspension is a bilateral phenomenon. After induction of anesthesia, first examine the scrotum to rule out incarcerated hernia or testicular tumor, both requiring an inguinal incision. Then proceed with a scrotal exploration via a vertical incision in the median raphae of the scrotum or two transverse incisions to access both sides.
Enter the serosal compartment of the scrotum to deliver and detort the testis. If it is necrotic, remove it. Orchidopexy of the viable testis is performed by suturing the surface of the testis (tunica albuginea) at four points to the wall of serosal compart- ment using non-absorbable sutures. If you find torsion of the testicular appendage, simply excise it.
Pediatric Abdominal Injuries
Trauma is the major cause of death among children older than 1 year of age, and is responsible for more deaths than all other causes combined. In about one injured child in seven, the most important injury is to the abdomen. The patterns of blunt abdominal trauma and the clinical picture are similar to those of adults, with injuries to the kidneys, spleen, liver and the intestines being the most common
(> Chap. 35). Most cases can be treated conservatively and laparotomy is required
only in one child in four. The major motivation for a non-operative approach to abdominal trauma in children is the risks of non-therapeutic laparotomy and over- whelming post-splenectomy infection.
Even children with hemodynamic instability on admission often quickly improve with crystalloid administration and remain hemodynamically stable thereafter. If the situation stabilizes after infusion of not more than 20 ml/kg of fluid then it is safe to observe the child in an intensive care unit.If the child continues to bleed and there is no other source of hemorrhage, a prompt laparotomy is indi- cated.
The Achilles heel of this conservative approach is the possibility of missed injuries to hollow organs. Thus if the child develops increasing abdominal tender- ness or peritonitis, this too is an indication for laparotomy.A useful clinical marker of blunt bowel trauma is the triad of a fastened lap belt, a seat belt sign on the abdominal wall, and fracture of a lumbar vertebra.
No discussion of pediatric trauma can be complete without emphasizing the need for a high index of suspicion for child abuse.While isolated abdominal trauma is a rare presentation of child abuse, unusually shaped or multiple bruises, associa- ted long bone fractures or inexplicable genital lesions should always raise the suspi- cion of this tragic and potentially life-threatening condition.
Children are not small adults but…see > Fig. 32.2.
Fig. 32.2. “But…but I’m a pediatric surgeon…”
