Paediatric Surgical Diagnosis Sanjay N Oak, Nitin G Chaubal, Naveen Viswanath
INDEX
×
Chapter Notes

Save Clear


The Child as a Patient1

What is Paediatric Surgery?
How does it differ from surgery of an adult?
Does a child withstand surgical stress?
Is the outcome acceptable?
These questions are repeatedly asked to paediatric surgeons and many myths and misconceptions still prevail. The most dangerous of the lot is that a child is a miniature adult and its requirements can be arithmetically deduced by using a diminutive quotient to adult values. This is unscientific and unsafe. A child has his own requirements; his own physiology which needs to be understood and respected.
It is essential that the anomalies and aberrations that occur in a child's physio-anatomy be diagnosed at the earliest and therefore complete and comprehensive assessment of the newborn as soon as he/she is born is of utmost importance.
 
 
Expecting the Arrival of a Newborn
To all intents and purposes neonatal surgery is the surgery of congenital malformations. It is therefore essential to know the frequency, aetiology, diagnostic features and preventive and therapeutic measures to reduce or eliminate the morbidity. Few of these have a tendency to repeat in the subsequent pregnancies and hence it becomes the foremost duty of the surgeon to counsel the couple properly.
A congenital anomaly is defined as any departure from normality, whether structural or functional. A congenital malformation is a structural abnormality. Two
or three percent of all the babies are born with a major malformation. The conditions given below make up about 60% of the total.
Early antenatal period (0–16 wks) is the most crucial one when most of these malformations sow the seeds. Genetic defects in the chromosomes, autosomal dominant or recessive traits, maternal infections with cytomegalovirus, rubella and toxoplasmosis, uncontrolled maternal diabetes and phenylketonuria, iodine and vitamin B 12 deficiency in the mother have been postulated to be the causes of many of the malformations. However, it must be admitted that for most of the malformations the exact cause is yet unknown.
 
 
Surgical Malformations Commonly Observed
  • Spina bifida and hydrocephalus
  • Intestinal atresia
  • Oesophageal atresia
  • Diaphragmatic hernia
  • Exomphalos and gastroschisis
  • Hirschsprung's disease
  • Anorectal malformations
  • Posterior urethral valves
  • Ectopia vesicae
  • Hydronephrosis
  • Lymphohaemangiomas
  • Tumours.
 
A BABY IS BORN
The joy of the new arrival is boundless however one must assess the baby as a whole. Many malformations 2are missed because the baby is not examined completely. The list of missed malformations is exhaustive. Oesophageal atresia may be missed and so even imperforate anus. Such mistakes prove to be fatal as the delay in the diagnosis adds to the morbidity of the newborn. Undescended testes have been missed and the children are brought for surgical help late in the infancy or even in late chilhood. It would be advisable to follow adjoining checklist in a newborn.
 
Newborn of Either Sex
  • Check patency of nasal canal
  • Pass No.10 Rubber catheter through mouth into stomach
  • Observe if alae nasae are moving.
  • Observe for jaundice.
  • Observe for tachypnoea.
  • Is the baby cyanotic?
  • Is there froth at the angle of mouth?
  • Is the baby vomiting? Gastric/bilious/blood
  • Is there substernal indrawing?
  • Is one side of the chest moving less?
  • Is the abdomen distended?
  • How are the flanks?
  • Is the anterior abdominal wall complete?
  • How is the umbilicus? Stretched/discharging/wet
  • Look for hernial sites – inguinal/umbilical.
  • Are the bowel loops seen or felt in the abdomen?
  • Are the lower limbs normal and equal?
  • Count the number of toes and digits.
  • Is there a swelling or a depression or a hairy patch on the back?
  • Look for the anus–Present? Patulous? Incontinent?
  • Is the genital area hyperpigmented?
  • Measure the head-circumference.
 
Male newborn
  • Are both the testes present in the scrotum?
  • Is the scrotum well formed?
  • Is there hypospadias?
 
Female Newborn
  • Are urethra/vagina and anal openings separate?
  • Are labial folds separate?
  • Is there a gonad felt in inguinal region?
  • Is there any obvious discord in the external sexual features?
 
Auscultation may Indicate
  • Reduced or absent air entry over lung fields
  • Shift of the apex beat
  • Cardiac murmurs
  • Rhonchi and crepitations
  • Peristalsis in the chest
  • Hyperperistalsis or silent abdomen.
  • Bruit over liver or intra-abdominal lump.
 
SCIENTIFIC DIFFERENCES BETWEEN INFANT AND ADULT
“The adult may safely be treated as a child, but the converse can lead to disaster”. This statement of Sir Lancelot Barrington Ward, made in 1926, sums up in one line the significance of peri-operative care in paediatric surgery.
The differences between an adult and an infant which have practical implications in diagnosis and treatment are as under.
 
Body Water
  • Total body water in a child with respect to body weight is more than an adult
    • 85% of body weight-water (infant)
    • 70% of body weight-water (adult)
  • Extracellular fluid
    • 40%-infant
    • 20%-adult
  • First 48 hours after birth there is a phase of physiological water loss.
  • By first month of life, kidneys acquire concentrating capability and stabilise in output quality and quantity.
  • Child is subjected to recurrent insults of loss of body water in episodes of diarrhoea, enterocolitis and urinary tract infections.
3
 
Temperature Regulation
  • Thermoregulatory mechanism of the child is poorly developed and they tend to take the temperature of their environment (Poikilothermia).
  • In an air-conditioned environment of operation theatre, recovery room, CT/MRI scan rooms and radiology suites, they tend to become hypothermic very rapidly.
  • Hypothermia leads to fast utilisation of body glucose, and later sets in a non-aerobic energy metabolism leading to metabolic acidosis; hypoxia and respiratory acidosis.
  • Newborns depend upon “Brown fat” for thermoregulation and have a mechanism of nonshivering thermogenesis.
  • Monitoring and maintenance of thermoregulation is of paramount importance (Fig. 1.1).
 
Surface Area
  • When related to body weight the surface area of an infant is more than double than that of an adult.
zoom view
Fig. 1.1: Maintenance of temperature and phototherapy for jaundice
  • Head, face and neck form a conspicuous part of surface area of child as compared to that of an adult
  • A relatively large surface area in an infant entails greater heat loss and consequently, caloric needs of an infant are raised.
  • A large surface area also leads to a large volume of fluid loss in a short period in cases of burns.
  • Intravenous infusion volumes; doses of chemotherapeutic drugs must be meticulously computed prior to administration.
 
Blood Volume
  • An average newborn weighing 2.5 kg has a blood volume of 200 ml.
  • A loss of even 20 ml of blood amounts to 10% loss of his blood volume.
  • Hence transfusion volumes as small as 15–20 ml are of paramount importance in paediatric surgery.
  • On the other hand if even 50 ml of blood is transfused rapidly; volume overload and circulatory failure may result.
 
Caloric Requirements
  • The basal metabolic rate and caloric requirements of an infant are two and a half times that of an adult and the protein requirements are twice that of an adult.
  • In a growing child; the additional demands for protein; calcium; zinc; and magnesium must be met.
 
Myocardium and Cardiac Volume
  • Cardiac volume of a child is small and myocardial contractile reserve is limited. Hence volume overload of circulation must always be avoided.
  • Early diagnosis of pulmonary oedema is also important.
 
Tidal Volume and Respiratory Capacity (Fig. 1.2)
  • Breathing pattern is predominantly abdominal (80%). Therefore any pathology that distends a child's abdomen (fluid; flatus; faeces; tumours) lead to respiratory distress.
    4
    zoom view
    Fig. 1.2: Neonatal mechanical ventilatory support
  • Similarly abdominal incisions and explorations make movements painful. Shallow respiration leads to low tidal volumes.
  • Increased need for oxygen can only be met by tachypnoea.
  • Increase in respiratory reserve by increasing depth of breathing is not feasible.
  • Developmental anomalies of diaphragm; renal system and lungs may render lungs hypoplastic.
  • In the immediate post-natal period when ductus arteriosus is not yet anatomically closed; a tendency to revert to foetal circulation exists and this can prove to be lethal.
 
Diagnostic Modalities
  • Non-invasive modalities of diagnosis including USG; Doppler and Echocardiography, are extremely valuable. Most of them can be employed from first trimester antenatally and can be repeated in follow up. Dynamic investigations are more helpful than static images.
  • 99mTc DTPA, DMSA and MAG-3 scans are more practical and useful than IVP.
  • Applications of duplex doppler scan for vesico-ureteral reflux and ICP monitoring is economical, trustworthy and non-invasive.
  • The overall aim of investigations must be clear and concise and investigations must be kept to minimum possible.
 
Clinical Features
In paediatric surgery, a young child very often cannot describe his ailment. Guardians and anxious mother may over-react to the disturbances. Therefore the surgeon must learn to decipher the correct meaning of a baby's cry.
  • A child may not vomit; may not be distended; may continue to pass stools and still has an obstructed GI tract.
  • A foreign body ingested, which fails to be passed out may indicate the presence of a web or a diaphragm within the lumen.
  • A urinary obstructing lesion may present with gastrointestinal features.
  • A dysplastic renal system may feature with respiratory insufficiency.
  • An intra-abdominal tumour may be brought to light by trauma.
  • Visual disturbances may indicate increase in ICP. A visit to an ophthalmologist for photophobia may indicate aniridia associated with Wilms' tumour.
 
Surgical Principles (Figs 1.3 to 1.8)
Every child admitted under “surgery” need not be operated upon. There is a definite role of “watchful conservatism” in paediatric surgery.
zoom view
Fig. 1.3: The baby weighed 900 g and had neonatal perforative peritonitis. After four years now he is a healthy playful child
5
zoom view
Fig. 1.4: Omphalopagus conjoined twins
zoom view
Fig. 1.5: Occipital encephalocele being operated upon in a 6-hour-old female newborn
zoom view
Fig. 1.6: Same newborn at 3 years of age
zoom view
Fig. 1.7: This 'smiling gentleman' underwent an exploratory laparotomy barely 24 hours ago
zoom view
Fig. 1.8: This 7-year-old girl was born with oesophageal atresia. She underwent gastric tube oesophageal replacement and four major operative procedures
  • In the first month of life
    • Operate only if it is life-saving.
    • Do the least and come out as quickly as possible.
    • Disturb the anatomy and physiology as little as possible.
  • In childhood
    • Exercise tissue respect
    • Replace lost volumes of fluid
    • Maintain caloric requirement
    • Maintain temperature
    • Perform meticulous haemostasis
    • Avoid hypoglycaemia and hypoxia
      6
    • Monitor pH of blood
    • Judicious use of antibiotics
    • Stress on day-care surgery and short admissions
    • Rehabilitation is as important as in-house treatment in hospital.
When a surgeon takes care of “milieu interior” of a child and does a dexterous, decent job, the results are often rewarding. Quality of life after surgery is excellent and a surgeon can then take pride in adding not only quantity but quality of meaningful existence to these tiny patients.
 
Minimal Access Surgery in Children (Fig. 1.9)
Within a relatively short period, laparoscopic approach has largely replaced open surgery for certain operations such as cholecystectomy, appendicectomy, surgery for cryptorchidism, anti-reflux surgery, etc. Several other operations can now be performed by laparoscopic approach but feasibility must never be equated with benefit to patient outcome.
The nonspecific depression of the immune system inevitable after classic open surgery is less pronounced after MAS. Wound related complications are also far less in MAS. Parieties are spared of the excess trauma and post operative morbidity is reduced. Hypertrophic scars are avoided. An open surgery also leads to hypothermia; drying out of tissues and handling leads to trauma and impaired healing in children. Due to magnification and good illumination endoscopic surgery gives a much better view and particularly exposure at cardiac end of oesophagus and in pelvic cavity is far superior to an open exploration. Laparoscopic approach elicits fewer adhesions than after open surgery.
zoom view
Fig. 1.9: This child underwent laparoscopic cholecystectomy just 6 hours back
The scope of MAS is to minimise the traumatic insult to the patient without compromise of the safety and efficacy of the treatment.
However, minimal access surgery is also not without limitations. These include:
  • Restricted vision: Display available even by the best CCD TV monitor is inferior to normal stereoscopic 3-D vision in terms of resolution, depth perception.
  • Kinematic restriction: The degree of freedom of movement available for manipulation is limited to 4 by the conventional straight long instruments and to 6 by curved co-axial instruments. This reduces the efficacy of MAS and prolongs the surgeries.
  • Reduced tactile and force feedback: Instrument tissue interface can give the tactile feedback to the surgeon; however a very long instrument and friction between the instruments and the ports reduces this feedback.
Paediatric laparoscopic surgeries can be classified into:
Group I: Operations where the laparoscopic approach provides an undoubted benefit and has replaced open intervention.
  1. Cholecystectomy
  2. Cryptorchidism (diagnostic and therapeutic)
  3. Fundoplications
  4. Adrenelectomy
  5. Varicocele operations
  6. Nephrectomy for benign conditions
    7
Group II: Laparoscopy appears beneficial and safer but more information is warranted.
  1. Appendicectomy
  2. Hernia repair
  3. Adhesiolysis
  4. Treatment of V. P. shunt complications
  5. Pyeloplasty
Group III: Operations, which are currently under evaluation and should not be attempted outside clinical trials
  1. TEF repairs
  2. Ureteric implantations
  3. Intestinal resection and anastomosis
Group IV: Unsuitable by laparoscopy. These are the operations where access trauma forms only a small percentage of total operative insult.
  1. Major cancer resections
  2. Hepatic resections
Complications during laparoscopy happen due to pneumoperitoneum and uncontrolled bleeding. Systemic complications include hypercarbia, acidosis and fatal pulmonary and systemic embolism. Veress needle or a trocar injury may injure viscera, viscus or vessel. Iatrogenic injuries also include bile duct injuries and ureteric trauma. Bowel and bladder injuries may be missed at the time of the initial operation. Injuries to bile ducts may also be addressed aggressively by either stenting it or by a roux-en Y hepaticojejunostomy.