During the last 25 years there has been an enormous improvement in the outlook for children who need to undergo surgical procedures. This change in prognosis is the result of a greater understanding of the physiology of children and an awareness of their special needs. Advances in anaesthesia, surgical procedures, and postoperative care have all made it possible to perform complex procedures successfully. The differences between children and adults are most marked immediately after birth, when the infant is adapting to extrauterine life. However such differences exist throughout childhood and must be understood and acted on if a satisfactory outcome is to be achieved.

All staff involved in the care of ill children should have appropriate training and experience. A team approach should include not only nurses and doctors, but pharmacists, laboratory staff, radiographers, and social workers.

As well as having unique physiological characteristics, children have special psychological needs, which the hospital environment must take into account. The family must be involved in the care of their child: staff must, therefore, be able to communicate with parents, siblings, and others who are close to the patient. The physical environment must provide space for private consultation with parents as well as sleeping accommodation and bathrooms. There must be arrangements for eating and access to a telephone.

Irrespective of the condition that leads to a child's admission to hospital, a number of important principles must be understood if hazards are to be avoided. Critically ill children are not ‘small adults’: unnecessary mistakes in management can occur if the differences are not appreciated. Surgical procedures undertaken in the first few days after birth carry particular risks; the process of adaptation to extrauterine life must not be adversely affected.

On admission, the child should undergo careful assessment from a medical and nursing perspective. The details of the presenting condition should be documented in full. Photographs taken with a Polaroid camera can be useful, particularly if a condition is developing rapidly and if the patient is being transferred to another hospital. Information concerning the maternal obstetric history must not be overlooked, even in an older child. Perinatal events and the state of the baby at birth must be recorded: evidence of birth asphyxia, possible aspiration, and the need for resuscitation should be noted. The family and social history should also be obtained immediately: these have implications for the impact of the child's illness.

Body temperature, heart rate, respiratory rate, and blood pressure must be recorded. Haematological and biochemical indices should be measured routinely and the urine analysed. Relevant specimens, including blood, should be sent for microbiological culture. Accurate measurement of body weight is of vital importance. Fluid therapy is adjusted precisely depending on weight; drug dosages are also related to weight, as well as to age.

Neonates are classified by their birthweight and by the length of gestation. The majority of babies are appropriately grown for their gestational age. If the birthweight lies below the tenth centile for gestational age the baby is classified as small for gestational age, and if greater than the 90th centile, as large for gestational age. Centile charts derived from local cohorts of babies should be used wherever possible, because of ethnic differences in birthweight.

Preterm babies are those born before 37 completed weeks of gestation, term babies are born at 37 to 42 weeks, and post-term babies are born after 42 weeks. The clinical problems seen in babies in these categories differ and those that commonly occur in low birthweight babies are listed in Table 1 553. Babies who suffer intrauterine growth retardation are often born to mothers with complicated pregnancy. Pre-eclamptic toxaemia, smoking, and drug addition are the most common factors associated with intrauterine growth retardation in ‘developed’ countries, while poor nutrition and infection are more common in other parts of the world.

Surgery planned for the management of congenital malformation soon after birth must take into account these problems to ensure that operations are carried out at the optimal time.

Preterm babies have conditions which reflect the immaturity of most systems of the body. A baby may be delivered preterm because of fetal and maternal illness and be of low birthweight (<2500 g), very low birthweight (<1500 g), or extremely low birthweight (<1000 g). The preterm baby must be supported to allow the process of maturation to take place after delivery. Clearly a baby may be born growth retarded as well as preterm.

Surfactant, a complex mixture of phospholipids and specific proteins, is released by type II cells in the lining of the alveoli. This substance reduces the surface forces in the terminal bronchioles and alveoli and prevents airway collapse. A deficiency of surfactant due to immaturity of the lung gives rise to the respiratory distress syndrome. The clinical signs of tachypnoea (<60 breaths/min), intercostal or sternal retraction, expiratory grunting, and central cyanosis in air may be present soon after birth in the most preterm infants; these may then require mechanical ventilation. Artificial surfactants can now be administered via an endotracheal tube to babies receiving artificial ventilation. Large randomized controlled trials have shown that such treatment reduces mortality by 40 per cent; the incidence of pneumothorax is also significantly reduced. The relative merits of early prophylactic use and delayed selective administration await the result of recent comparative studies. In babies born between 30 and 34 weeks' gestation the signs of respiratory distress syndrome may take a few hours to develop; these babies must be observed carefully. The severity of any respiratory disease and the underlying cause must be taken into account when planning the timing of surgery soon after birth.

Babies lose body heat very quickly unless nursed in an environment with an optimal temperature at which oxygen consumption is minimal. In a cold environment catecholamine secretion is stimulated through hypothalamic receptors. In an attempt to maintain body temperature brown fat stores, predominantly alongside the scapula and aorta, are broken down by oxidative phosphorylation to release heat. This process of non-shivering thermogenesis, which increases oxygen consumption, is limited during the first 12 h after birth and may be impaired after asphyxia or hypoxia and maternal sedation; it may be non-existent in the most immature infants. Ideally, therefore, term babies should be kept in conditions in which oxygen consumption is kept to a minimum while the core (rectal) temperature is maintained at 37°C (within the range 36.7–37.3°C) and skin temperature at a range of 36.2 to 36.8°C. Infants with cardiorespiratory disease, or impaired nutrition as a result of gastrointestinal disorders, and preterm infants with respiratory disease are at greatest risk of cold stress. Despite the existence of compensatory mechanisms heat loss occurs rapidly because of the large surface area to body weight ratio and inadequate fat stores. The four different routes through which heat loss occurs and the approaches that can be taken to minimize this risk are shown in Table 2 554.

The skin must be dried with warmed towels and the baby well covered. If body temperature is normal, further losses by radiation can be minimized by an aluminium foil wrap over the blanket. This is not a substitute for warming the baby first if heat loss has already occurred, as can happen during resuscitation, but may prevent further losses while the baby is being moved to the nursery. An infant undergoing an operation is subjected to additional thermal stresses due to starvation and sedation which blunt the physiological response to cold stress. Before transport from the intensive care nursery the baby should be well wrapped and insulated by cotton wool padding. Increasing the operation theatre temperature to 28°C, avoiding draughts, and the use of a warming pad below the body can minimize heat loss. The part of the body exposed should be kept to a minimum, and intravenous fluids and blood products should be allowed to warm to room temperature before use.

Immaturity of respiratory control is particularly common in preterm babies, but apnoea can occur in any sick infant. Respiration must be monitored and heart rate and oxygen tension should be measured continuously in severely ill infants. Apnoea may reflect other problems, such as hypothermia, sepsis, or deranged biochemical states, particularly hypoglycaemia. After these abnormalities have been investigated and treated, and if attacks do not respond to tactile stimulation, aminophylline (6 mg/kg intravenously followed by 4 mg/kg.day intravenously) should be given. Artificial ventilation, first by continuous positive airway pressure and finally by intermittent positive pressure, may be necessary. Immature respiratory control may be responsible for a slower than expected postoperative recovery and should be considered when other complications have been excluded.

After birth bilirubin is excreted in bile in the water-soluble conjugated form. In the first few days after birth, while the liver enzymes are maturing, clinical jaundice may become apparent when the serum bilirubin rises above 85 &mgr;mol/l (5 mg/dl). A level greater than 150 &mgr;mol/l on the second day of life or 250 &mgr;mol in the first week in a term baby requires further investigation. Bruising during delivery is a common cause of jaundice; this may also occur if there is polycythaemia. Jaundice associated with lethargy may be the first sign of systemic infection or a haemolytic process. Rare metabolic causes such as galactosaemia must be considered if jaundice persists.

A low serum albumin level and the presence of hypoxia contributes to the risk of kernicterus, a disorder in which free unconjugated bilirubin enters the lipid fraction of brain cells and causes an encephalopathy. Jaundice may complicate many surgical conditions in which bowel obstruction occurs below the ampulla of Vater, such as intestinal atresia, Hirschsprung's disease, and meconium ileus. Conjugated hyperbilirubinaemia occurs in biliary atresia, choledochal cyst, or other causes of obstruction to the bile duct such as inspissated bile syndrome.

Management of neonatal jaundice depends on a careful history and identification of the cause. The majority of well babies born at term need no treatment. Preterm babies and those who have suffered asphyxia or extensive bruising need phototherapy at lower serum bilirubin levels. If jaundice develops within the first 24 h after birth, investigation into the cause and phototherapy should be started immediately. When haemolysis is present due to rhesus incompatibility, the need for exchange transfusion will depend on the rate of rise of the serum bilirubin concentration, the absolute level, and the gestational age of the baby. Haemolysis due to ABO or other blood group incompatibility may also require active treatment (Table 3) 555.

Term babies should ideally receive breast milk. Breast feeding cannot be fully established if a neonate requires emergency surgery, and is interrupted when elective surgery is necessary. In both situations arrangements must be made for the mother to express her milk until feeding can recommence. Low birthweight or sick babies should be fed through an orogastric tube if enteral feeds can be given. Specific formulae are now available for the low birthweight baby if breast milk is not available: careful attention must be paid to the volume of fluid given, which will depend on the state of hydration, as well as the volume and specific gravity of urine. Any increase in insensible fluid losses, such as those which can occur if a preterm baby is nursed under a radiant heat warmer or when internal surfaces are exposed (as occurs in gastroschisis and exomphalos), must be taken into account. Urine volume is usually in the range 1 to 3 ml/kg.h and urine specific gravity is below 1012. The normal daily maintenance fluid requirements are shown in Table 5 557. Adjustments need to be made on the basis of body weight, serum electrolyte concentrations, plasma and urine osmolality, and the measured and insensible water losses. Inappropriate secretion of antidiuretic hormone leading to abnormally low serum sodium and osmolality, with concentrated urine, can occur after severe infections, pulmonary and neurological disorders, and neonatal surgery. Treatment is by fluid restriction. Extra intake of electrolytes through fluids administered intravenously must be taken into account and other sources of electrolytes such as antibiotics (e.g. sodium penicillin) may need to be included. The standard electrolyte intake is shown in Table 6 558. Sodium intake will need to be adjusted if there are abnormal losses or if secretion of ADH is inappropriate, and potassium intake must be monitored carefully if the baby has any bruising. Intravenous electrolyte supplementation can usually be discontinued when a baby is taking more than half the fluid requirements in the form of milk.

Babies, particularly those born preterm, are at increased risk of infections because of deficiencies in their defence mechanisms. Colonization with organisms acquired from the birth canal and the immediate hospital environment is rapid. The thin, easily damaged skin of the newborn and the umbilical stump can be sources of infection. The transplacental passage of maternal IgG is the main source of humoral immunity in the neonate; because passage occurs mostly in the last trimester, preterm babies are at special risk. Cellular immunity is also deficient. Leucocytes have impaired chemotaxis and phagocytosis, and their absolute number is reduced.

Obsessional attention to hand washing by all staff and parents is essential if cross-infection is to be minimized. Equipment such as stethoscopes should be provided for each baby or carefully disinfected before and after use. The wearing of gowns, masks, and gloves does not reduce the risk of cross-infection and is unnecessary, except when staff need to be protected.

Laboratory investigations should be carried out as soon as infection is suspected or when the maternal history, particularly during the labour, suggests that the risk of infection is high (Table 7) 559. The clinical signs of infection in the newborn are often non-specific. Poor feeding with vomiting, temperature instability, hypotonia, apnoea, jaundice, tachypnoea, and hypoglycaemia are some of the early signs.

A ‘sepsis screen’, must be carried out promptly, and antibiotic treatment started without delay. The specimens to be collected and sent for bacterial and viral culture are shown in Table 8 560. Other investigations should be performed on the basis of clinical indications. Such investigations may include chest and abdominal radiographs, urinalysis and measurement of blood glucose, serum urea and electrolytes, and arterial pH and blood gases.

In addition to minimizing the problems associated with cold stress and inadequate feeding, babies suffering from infection may need ventilatory support for apnoea and respiratory failure. Inadequate peripheral circulation and hypotension must be treated with fresh frozen plasma, (10 ml/kg over 20–60 min); this may need to be repeated. Anaemia should be treated by blood transfusion; this may be urgent if oxygen requirement is increasing. Hypoglycaemia should be treated immediately, while serum electrolyte abnormalities must be corrected gradually.

Initial therapy should be with antibiotics active against the spectrum of bacteria prevalent in the nursery. The organisms causing sepsis and the efficacy of the standard antibiotic policy should be continuously monitored.

In Oxford, penicillin G and an aminoglycoside have been found to be satisfactory empirical treatment for early-onset sepsis. Ampicillin, instead of penicillin, is favoured by many, but monotherapy with a third-generation cephalosporin is inadvisable since these drugs are ineffective against Listeria monocytogenes. The current standard regimen for suspected late-onset sepsis is flucloxacillin and netilmicin. Therapy can be changed on the basis of the results of cultures and clinical conditions. Systemic infection with Staphylococcus epidermidis is a particular hazard in infants with centrally placed silastic cannulae or ventriculoperitoneal shunts. Treatment of such sepsis may be unsuccessful until the foreign plastic is removed.

Frequent ultrasound scans of the brain, particularly in babies born at less than 33 weeks' gestation, will detect periventricular haemorrhage. This may occur in the first few days after birth and be followed by ventricular dilation. Periventricular leucomalacia as a result of ischaemic damage to the brain may be detected in the second and third weeks after birth. The cerebral blood flow in sick newborn babies is unstable and the adverse effects of sudden changes in cardiac output and blood pressure must be taken into account during surgical procedures. Hypoxia, hypercapnoea, and acidosis must be avoided.

A venous haematocrit above 65 per cent increases blood viscosity. This is most common in growth retarded infants, those born post-mature, or those born to mothers with pre-eclamptic toxaemia or diabetes. Delayed cord clamping and twin-to-twin transfusion lead directly to polycythaemia. Symptoms are attributable to inadequate blood flow through the capillary bed of various organs. Respiratory distress and cyanosis, hypoglycaemia, irritability, hypotonia, and lethargy may occur. Seizures, necrotizing enterocolitis, renal vein thrombosis, and peripheral gangrene occasionally occur.

If the haematocrit is between 65 and 70 per cent and any symptoms are present a dilutional exchange transfusion with plasma should be carried out. A haematocrit above 75 per cent should be reduced even if there are no symptoms.

The level of anxiety, distress, and pain that a child experiences will depend on the circumstances and the clinical condition. All staff must recognize and respect the special needs of children and make an approach which is appropriate to their age and psychosocial development.

Children at greatest risk of subsequent psychological problems after an admission to hospital are those aged 6 months to 4 years who have either endured a long hospital stay or who have repeated admissions. Their response depends on the stage of development, the diagnosis, the family environment, and personal attitudes. Infants and toddlers may show regressive behaviour, such as clinging and decreased interest in play and physical contact. Slightly older children may regard their illness as a punishment. School-aged children may become physically and verbally aggressive; they need to be given the opportunity to have their questions answered and to be actively involved in their treatment. A visit to the hospital prior to admission can be a great advantage in this respect. Adolescents are more able to deduce the sequence of events and can analyse the experience independently. Respecting their need for privacy and encouraging involvement in their care can contribute to a successful outcome. Clearly the diagnosis and subsequent treatment play a major part in influencing a child's behaviour. In addition a full understanding of a child's social circumstances, including other illness in the family and possible experience of a grandparent's death, for example, are important factors.

Effective communication between all the staff involved, as well as consistent and frequent discussions with the parents and child, are an integral part of the treatment.

The ability to recognize illness in a child is an important asset for any member of the clinical team. Examination should involve an immediate assessment of the level of consciousness, degree of distress, and, if possible, localization of pain. The state of peripheral perfusion, hydration, and presence or absence of anaemia or cyanosis must be noted. Lack of eye contact, hypotonia, and irritability when roused are often signs of illness.

A child's blood volume is approximately 80 ml/kg. In addition to any traumatic blood loss, blood taken for laboratory analysis must be recorded and a cumulative total kept. Laboratories should use micromethods, as frequent samples often need to be taken.

Normal heart rate decreases from an average of 145 beats/min at the age of 1 month to 70 beats/min at 14 years. Tachycardia will normally increase cardiac output and should be expected to a certain degree when cardiorespiratory disease is present. Blood pressure increases gradually throughout infancy and childhood, reaching adult levels by 14 years.

In childhood lung compliance increases from 5 ml/cmH&sub2;O to 70 ml/cmH&sub2;O by 7 years; this is approximately half the adult value. The chest wall becomes more rigid throughout this time, increasing the efficiency of ventilation. Because of the small tidal volume, mechanical ventilators for children must have characteristics that enable low pressures and short respiratory times to be used.

The assessment of neurological integrity in a sick child requires knowledge of the normal stages of development throughout childhood. Management of severe encephalopathy after trauma or infection should only be carried out in a centre which has full monitoring facilities.

Fluid must be administered to a sick child via a volume-controlled infusion pump, and must be monitored on an hourly basis. All sources of fluid intake and loss should be taken into account when fluid requirements are calculated. Hypoglycaemia is common in children, and an intravenous infusion should be maintained until they are able to feed normally. Caloric intake must be maintained and enhanced in all conditions that lead to a higher metabolic rate. These include cardiorespiratory distress, sepsis, pyrexia, and trauma, particularly after burns and during the postoperative phase.

A neutral thermal environment, whilst most important in the care of the newborn, can also contribute to the wellbeing and recovery of older children. Unnecessary distress from overheating as well as from underheating must be avoided, particularly in children who are unable to move fully.

The risk of nosocomially acquired infection increases postoperatively, particularly when ventilatory support and central catheters continue to be necessary. Meticulous attention to hand washing before and after examination of the child is essential.

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