Ghai Essential Pediatrics8th

AGENT

Excess energy

Thermal

Electrical

Chemical

Radiant

Lack of vital elements

Oxygen

Temperature

Fig. 26.2: The epidemiology of childhood injuries

i.Passive injury prevention, such as automatic locks for medicine cabinets, are preferred over active strategies, e.g. "yuck" stickers on bottles.

ii.Specific instructions, e.g. keep water heater temperature lower than 120°F, are more likely to be followed than general advice, e.g. reduce the temperature of hot water tap in your home.

iii.Reinforcement by community wide education programs are more effective than individual education sessions.

Targeted messages for prevention of injuries should be discussed with the parents (Table 26.10).

Fire and Burns

Injury followingburnsis an important cause of deathin India. Scald burns secondary to household accidents constitute 70% of all thermal injuries in infants, toddlers and preschool children. Burns may also occur with chemicals (particularly corrosives), cigarettes (child abuse) and electrical current. Burns have higher mortality in children than adults since the former have (i) thinner and more sensitive skin, (ii) markedly increased ratio of body surface area to body mass; (iii) limited physiological reserves; (iv) significant metabolic and systemic disturbances; (v) immature immune system; and (vi) increased fluid requirements.

First Aid

While approaching a child with fire, a blanket or coat should be kept in between rescuer and the burning child. Flames may be extinguished with water, blanket or by rolling the victim on the ground. Running with clothes on fire is avoided. The victim is kept lying in flat position away from source of heat.

Poisoning, Injuries and Accidents

In case of minor burns or scalds, one should pour cold water, apply cold water soaks or submerge the burned portion immediately in cold water, continuing till pain disappears. Application of any ointment, grease, soda, oil, powder, butter or herbs is avoided. Blistered skin is not ruptured; it should instead be covered with a clean cloth. Charred cloth is removed only if it comes out easily. The wound is covered with clean sheets of sterile dressing and the patient is wrapped in blanket or foil.

Inhalation injury, frequently associated withlargebums, is an important early predictor of mortality and is the most common cause of death during the first hour after burns. The singeing of thenasal vibrissae is commoninfacial burns but does not reliably indicate inhalation injury.

Electrical burn. The power supply should be switched off. Using nonconductor material like dry wooden stick or dry cotton clothes, the victim should be pulled away from the electric source.

Chemical burns. The burnt area should be flushed with plenty of running cold water. If an eye is burnt by che­ mical, especially an acid or an alkali, it should be flushed gently but thoroughly with tap water for prolonged time. Both eyes should be covered with clean cloth. The burn wound should be kept as clean as possible, protecting it from dust and flies.

Management

Estimation of burn size. The primary determinants of survival in patients with burn injury are patient age and the size and depth of the burn wound. Young children below 4 years of age do not tolerate thermal injury as well as adults. The Berkow body surface area chart and the rule of nines used to estimate surface area with burn injuries in adults are not applicable to children. The Lund and Browder modification, which divides the body into smallportions and takes into account childhood differences in body proportions, is used. More simply, the child's palm together with fingers is considered as representing 1% of total body surface area (TBSA).

Hospitalization. Minor burns can be treated at home with topical ointments. Indications for inpatient care include:

(i)third-degree burns involving 5% or more of TBSA;

(ii)second-and third-degree burns involving more than 10% TBSA; and (iii) burn injuries involving the face, hands or genital areas.

Resuscitation. The goals of resuscitation and early manage­ ment are: (i) adequate fluid replacement; (ii) correction of hypoxia and ventilatory disturbances; (iii) prevention of hypothermia; and (iv) adequate control of pain and anxiety. Children with inhalation injury should be intubated and supportive ventilation is initiated early; hyperventilation with 100% oxygen shortens the half-life of carbon monoxide elimination from 4 hr to 40 min.

Don'ts

Allow children to fly kites in rain or on terrace Allow playing with plastic bags, electric cords, dupatta, sharp objects, beads, coins or small toys with detachable or moving parts

Allow children to play on the stairs or balconies without railings or terrace without parapet wall Leave oil, grease or liquid soap on the floor Keep chair or furniture near open windows or galleries

Keeplarge toys in the crib (infant may step on them) Leave any sharp objects near the vicinity of the child

Allow to run or play with sticks or any sharp objects Let child enter the kitchen to recover a toy

Leave hot utensils or pans in the kitchen within the child's reach

Leave an electric iron switched on close to a child

Drink or pass hot tea or coffee while holding the infant

Keep electric equipments plugged on when not in use

Keep electric cables within the reach of children

Leave any medicines in the child's bedroom Store inedible products in food shelves Take medicines in front of the child

Leave young children and those with history of seizure(s)unattendedin bathtubs ornearswimming pools,ponds,beaches or fullbucketsin the bathroom

Give (pea) nuts to children below 2 yr of age Give bolus of food to infants or toddlers

Allow children to run about with food in the mouth or to play while eating

Light firecrackers in hand; bend over while lighting crackers; touch half-lit firecrackers

Allow younger children to cross the streets alone Allow doubling on the bicycle, especially with infants

Carry more than one child on a 2-wheeler; allow child to stand in front of a rider

Riding at night; play near/on roads

Allow child to occupy front seat of car, lean out of vehicle windows or take any body part out of the window

Adequate fluid replacement. The goal of fluid resuscitation is to restore and maintain perfusion and tissue oxygen delivery at optimal levels in order to protect the zone of ischemia in burnt tissues without overloading the circu­ lation. Monitoring urine output and a nasogastric tube for continuous suction to prevent emesis and aspiration are essential. Oliguria occurs due to dehydration and other factors, including excessive secretion of antidiuretic

hormone. Urine output should be maintained between 0.7-1 ml/kg/hr. Isotonic solutions (normal saline or Ringer lactate) should be administered initially at a rate of 20 ml/kg/hr until calculation of appropriate replacement canbemade. The Parkland formula estimates the amount of fluid to be replaced over 24 hr as follows:

Volume of Ringer lactate (mL) = 4 ml x weight (kg) x % TBSA burn

In addition, the child require maintenance fluid therapy. However, while this estimation is adequate for children over 10-yr-old, the formula underestimates the requirements for children weighing less than 20 kg. Potassium is not administered during the first 12-24 hr, or until normal kidney function is demonstrated.

Topical therapy. 65% ofpediatric bums heal spontaneously, without the need of skin grafting, with topical therapy alone. The most commonly used topical agents are 0.5% silver sulphadiazine, 0.5% silver nitrate and mafenide acetate. Silver sulphadiazine offers advantages in small children; its application is painless, it has a soothing effect and restricts fluid and heat loss from the bum surface. It can cause skin rash, leukopenia and thrombocytopenia. Silver nitrate is not an effective antibacterialagent because of poor penetration of the bum eschar. Further, it cancause hyponatremia, hypokalemia, hypochloremia and hypo­ calcemia. Mafenide acetate penetrates the burn eschar effectively; its application can be painful and may be associated withskinreaction and metabolic acidosis since itis acarbonicanhydraseinhibitor. Dailydressingchanges are required after thorough cleansing. Maintaining such dressings intact in a young child is difficult over the face and hands. Moist exposed burn ointment (MEBO) is promising in this regard. A judicious combination of topical therapy, eschar excision and skin grafting helps in quick healing. Decompressive escharotomy of circum­ ferentialburns of thechest,abdomenand extremities must be performed without delay.

Analgesia. Adequate controlof pain and anxietyis essential to minimize the stress response in bum injury. Narcotics are the commonest form of analgesia in major burns.

Nutrition. Attention to the nutritional needs of a burned child is an essential component of management (Table 26.11). High caloric and nitrogen intake is crucial for survival.

Table 26.11: Caloric requirement in children with bums

Infants: 2100 Cal/m2 + 1000 Cal/m2 burn surface area Children: 1800 Cal/m2 + 1300 Cal/m2 bum surface area Adolescents: 1500 Cal/m2 surface area and bum surface area

Adequate protein intake (2-3 g/kg body weight) and supplementation of trace vitamins and minerals are necessary. Whenever feasible, particularly in children with less than15-20% bums, nutrients should be administered by the enteral route. Tube feeding is started on the first day of admission with rapid advancement towards intake goals. In children with more extensive bums, inhalation

Poisoning, Injuries and Accidents -

injury or prolonged paralytic ileus, parenteral nutrition may be considered.

Supportive measures. Assessment of physical abilities and enabling full range of joint movements by physical and occupational therapy and play therapy is encouraged. Family support and evaluation of the child's social environment should not be overlooked.

Drowning

Drowning is a form ofasphyxia!death in which the access of air to the lungs is prevented by the submersion of the body in water or other fluid medium. In India, drowning is animportantcause ofchildmortality.Thoughdrowning occurs most frequently in natural bodies of water like ponds, lakes and rivers, deaths due to drowning in swimming pool and bath tubs are increasing.

Aspiration and Suffocation

Many young children die every year due to suffocation caused by ingestion of foreign objects. More than 50% accidental deaths among infants are caused by aspiration of food during or after feeding. Peanuts are usually

responsible for aspiration-related suffocation fatalities in I 2-4-yr-old children. Eating rapidly, improper chewing,

runningwithfoodinmouthorholding apotentialforeign body in the mouth (such as a pin, nail or small toy) may cause such accidents. Less common reasons include accidental suffocation due to pacifier cords, cords of cradles, smallchains,necklaceandrarely,bybeingcrushed by adults sleeping in the same bed as a young infant.

Most injuries can be prevented by ensuring discipline, which includes immediate stopping of all dangerous practices such as door banging, throwing objects around the room and playing on the stairs. Even a young child of 1 to 1 yr can be trained to keep away from the kitchen stove or electrical connections. Parents should not allow any dangerous habits such as turning on the gas taps that are done for attention seeking. However, they should be awarethat excessivedisciplineandoverstrictness mayforce their children to rebel against restrictions making them vulnerable to injuries.

Suggested Reading

Child Health Dialogue 15. Dealing with accidents and injuries. www.healthlink.org.uk/PDFs/chd15.pdf

Children's Environmental Health Annual Report 2011. http:// www.who.int/ceh/pubbcations/ceh_annualreport_201l.pdf

Summary of principles for evaluating health risks in children associ­ ated with exposure to chemicals. http://www.who.int/ceh/publica­ tions/health_risks_exposure_chemicals/en/index.html

The availability of facilities for pediatric intensive care has resulted in improved child survival. In tertiary care hospitals, 5-10% of total pediatric beds should be earmar­ ked for ICU; greater if the hospital has surgical units. The common indications for admission to PICU are listed in Table 27.1.

Table 27.1: Indications for admission to PICU

Hemodynamicinstability or shock requiring inotropic support and intensive monitoring; cardiac arrhythmias or cardio­ respiratory arrest; severe anemia or hemorrhage Respiratory distress requiring oxygen therapy; impending or establishedrespiratoryfailurerequiringmechanicalventilation

Altered sensoriurn due to any cause; encephalopathy; status epilepticus; raised intracranial pressure

Acute hepatic failure or its complication Acute renal failure or its complications

Severehyperor hypokalemia; severe hyperor hyponatremia; hypoglycemia; diabetic ketoacidosis

Severe malaria; severe pneumonia Acute poisoning

Procedures: Peritoneal dialysis, exchange transfusion, central venous cannulation, postoperative monitoring

The optimal number of beds in an ICU is six to ten, with an area of about 200-250 square feet provided per bed. The unit should have an uninterrupted power supply. Preferably, the unit should be air-conditioned. The type and arrangement of beds should allow rapid access to the head end for airway management. A trolley having all the necessary drugs and resuscitation equipment should be available all the time. The ICU should have equipment for cardiorespiratory monitoring, ECG monitoring, pulse oximeters, devices for oxygen therapy, mechanical ventilators, nebulizers and devices for IV therapy including infusion pumps. The ICU should have access to laboratory facilities, preferably relying on micro-

Rakesh Lodha, Manjunatha Sarthi

methods. The ICU physicians, nurses and technical staff have a key role in care of critically ill children.

Suggested Reading

Consensus guidelines for pediatric intensive care units in India. Indian

Pediatr 2002;39:43-50

ASSESSMENT AND MONITORING OF

A SERIOUSLY ILL CHILD

Assessment

The primary assessment is done using the ABCDE approach. A stands for 'Airway assessment' and is categorized as clear, maintainable and not maintainable. B stands for 'Breathing assessment' and includes the respiratory rate, respiratory effort, tidal volume, abnormal sounds by auscultation and pulse oximetry. C stands for 'Circulation assessment' by skin color and temperature, heart rate, heart rhythm, blood pressure, central and peripheral pulses, capillary refill time and assessment of end organ perfusion (mental status, skin perfusion and urine output). D stands for 'Disability' which establishes the level of consciousness and is assessed by AVPU pediatric response scale (A for alert, V for response to vocal stimuli, P for response only to painful stimuli, or U if unresponsive) or the Glasgow Coma Scale and pupillary response to light. E stands for 'Exposure' where the body parts are examined for temperature (hypoor hyper­ thermia), skin rashes or wounds.

Features suggestive of serious illness are listed in Table 27.2. These featurespredict a serious condition particularly in young infants. In addition, history should focus on identifying any underlying chronic illness. Commonly performed investigations in a sick child include complete blood count, blood glucose and electrolytes, and if feasible, arterial blood gas estimation. Further investigations are tailored to the clinical profile.

Table 27.2: Common danger signs in children

Drowsiness, decreased activity Excessive or inconsolable cry Seizures

Increased work of breathing Abnormal sounds on breathing Apneic episodes or cyanosis

Cold extremities (particularly in warm environment) Decreased urine output (e.g. less than 4 wet nappies in 24 hr) Decreased feeding or decreased intake of fluids

Bilious vomiting

Monitoring

Monitoring of critically ill children is an essential compo­ nent of management. The purposes of monitoring are: (i) to measureintermittentlyorcontinuouslykeyindicesthat help in early diagnosis and management; (ii) to provide alarms that notify the health care team that changes have occurred in the child's condition; and (iii) to evaluate trendsthathelpin theassessment of response to treatment and prognosis.

Respiratory Monitoring

Physical examination. The child should be observed for respiratory rate and pattern, nasal flaring, use of accessory muscles and color. Auscultation is done for symmetry of air entry, type of breath sounds and presence of stridor, rhonchi and crepitations.

Use of monitors. Respiratory rate (Table 27.3) can be monitored continuously by impedance pneumography, which requires the presence of three electrodes over the chest. Pulse oximetry has made it possible to noninvasively measure percent oxygen saturation of hemoglobin. Pulse oximetry is reliable in most settings. However, some conditions lead to inaccuracies, e.g. dyshemoglobinemias (methemoglobin, carbon monoxide), dyes and pigments (methylene blue), poor peripheral perfusion, increased venous pulsations and optical interference with external light sources like phototherapy unit or fluorescent light.

Table 27.3: Normal respiratory and heart rates according to age

Numbers in parentheses indicate normal range

Pediatric Critical Care -

Transcutaneous blood gas monitoring is now feasible and makes continuous monitoring of P02 and PC02 possible. However, it has limitations of need for frequent cali­ bration, highcostsandoccasionalbums.Capnography isthe graphicwaveformproducedby variations in CO2 concen­ tration throughout the respiratory cycle. A side stream or mainstream sampler samples the gases inspired and expired by the patient. CO2 is estimated in these samples by infrared spectroscopy. End-tidal CO2 can be used a substitute for PaC02. EtC02 also has a role in determining endotracheal tubeplacement, deadspace, and mechanical ventilation failures. In mechanically ventilated children, respiratorymechanicshelpinunderstandingofrespiratory pathophysiology.Apartfromthesecontinuousmonitoring modalities, chest radiography and arterial blood gas analyses are performed periodically.

Hemodynamic Monitoring

Physical examination. Repeated examination of a critically ill child is the cornerstone of hemodynamic monitoring. The rate and characterof pulse should be examined. Blood pressure can be monitored by noninvasive or invasive methods. The pressures may be determined manually (aneroid manometers) or by use of automated (oscillo­ metry) systems. Invasive methods rely on placement of a catheter in an artery and pressure measurement by manometer.

Thestateofmicrocirculationcanbeassessedbythecapil­ laryrefilltime.Pressure is appliedwith theindexfinger or ball of thumb over sternum or forehead for 5 seconds to causeblanching. Onremovalofpressure, thecolorreturns andthetimetakenforcompletereturnofcolorisnoted.The normal capillary refill time is 3 seconds or lower; pro­ longationsignifies impairment of microcirculation. This helps in diagnosing hemodynamic compromise earlier than drop in arterial blood pressures. Another way of determiningadequacyoftheperipheralperfusionisnoting thecoreperipheraltemperaturegradient;gradientofmore than 5°C indicates hypoperfusion.

Continuous ECG monitoring. This is mandatory in critically ill children admitted in ICU.

Central venous pressures. These are monitored by placing a catheter through a large vein into the right atrium. The pressuregivesinformationaboutthevenousreturnandthe

preload.Normalright atrialpressureislessthan6 mmHg. Ifthepressureislowinachildwithhypotension,itsignifies a low intravascular fluid volume. On the other hand, central venous pressure may be increased due to myo­ cardialdysfunction,fluidoverloadorincreasedpulmonary artery pressures.

Monitoring vital organ perfusion. This is assessed by monitoring urine output, which is a surrogate marker of renal perfusion and function. Urine output less than 0.5 ml/kg/hrina childwith normal kidneys signifies poor

renal perfusion. Monitoringofthesensoriumandneurologic status also gives information about vital organ perfusion.

Suggested Reading

Cheifetz IM, Venkataraman ST, Hamel OS. Respiratory monitoring. In: Nichols, David G, (Eds.). Roger's Textbook of Pediatric Intensive Care, 4th edn. Philadelphia (USA): Lippincott Williams & Wilkins, 2008; 662-85

Frankel LR. Monitoring techniques for the critically ill infants and children. In: Behrman RE, Kliegman RM, Jenson HB (Eds) Nelson Text book of Pediatrics,19th edition. Philadelphia: WB Saunders; 2010

Halley GC, Tibby S. Hemodynamic monitoring. In: Nichols, David G, (Eds): Roger's Textbook of Pediatric Intensive Care, 4th edn. Philadelphia (USA): Lippincott Williams & Wilkins, 2008;1039--03

TibbySM, MurdochIA. Monitoring cardiacfunction in intensive care. Arch Dis Child 2003; 88:46-52

PEDIATRIC BASIC AND ADVANCED LIFE SUPPORT

Cardiopulmonary arrest in children is much less common thaninadultsandfrequentlyrepresentstheterminalevent of progressive shock or respiratory failure. The major causes of death in infants and children are respiratory failure, sudden infant death syndrome, sepsis, neurologic diseases, submersion or drowning and injuries. Basic life support (BLS) refers to a protocol mandatory in cases of cardiopulmonary arrest providing cardiopulmonary resuscitation (CPR)withorwithoutdevices andbag-mask ventilation till advanced life support (ALS) can be pro­ vided. Two major objectives of cardiopulmonary resusci­ tation are to preserve organ viability duringcardiac arrest and to help return of spontaneous circulation.

Basic Life Support

To maximize survival and intact neurological status in postresuscitation stage, early recognition of the cardiac arrestandstrictadherencetotheBLSsequenceisnecessary. BLS guidelines give a series of skills performed sequen­ tially to assessand restore effective ventilation and circu­ lation in the child with respiratory or cardiorespiratory arrest. Evaluation and interventions in pediatric BLS should be a simultaneous process. The sequence of BLS is

(i) assessment; (ii) circulation; (iii) airway; and (iv) breathing.

Assessment

Initial assessment is done to look for the evidence of cardiac arrest so that life-saving measures such as CPR are initiated. The most accurate method of recognizing cardiac arrest is the combination ofunresponsivenessand absent or abnormal breathing. Palpation of the pulse (for its absence) as the sole determinant of cardiac arrest is unreliable. If the victim is unresponsive, not breathing normally and there are no signs of life, rescuers should begin CPR. In infants and children with no signs of life, health care providers should begin CPR unless they can definitely palpate a pulse within 10 seconds.

Circulation

The CPRshouldbeginwithchest compressionratherthan opening the airway and delivering the rescue breathing. Chest compressions are serial rhythmic compressions of the chest that cause blood flow to the vital organs (heart, lungs and brain) in an attempt to keep them viable until ALS (advanced life support) is available. To provide optimumchestcompression,victimshouldbelyingsupine onahardandflatsurface. Highqualitychestcompressions shouldbegivenby pushing hard,toadepthofatleastone­ third the anterior-posterior dimension or approximately 11h inches (4 cm) ininfants, and at least one-third the ante­ rior-posteriordimension or approximately2 inches (5 cm) inchildren. Thecompressionrateshould beatleast100per minute, allowing full chest recoil and minimizing the interruptions in chest compressions.

Chest compressions in infants (<l yr)

i.Two-thumb technique. The infant's chest is encircled withboth hands; fingers arespreadaround thethorax and the thumbs brought together over the lower half of the sternum avoiding the xiphisternum. The ster­ num is compressed with the thumbs and the thorax with the fingers for counter pressure. The 2 thumb­ encircling hands technique is preferred because it produces higher coronary artery perfusion pressure, moreconsistentlyresultsinappropriatedepthorforce of compression and may generate higher systolic and diastolic pressures. Whileoneprovider performs chest compressions, the other maintains the airway and performs ventilations at a ratio of 15:2with as short a pause in compressions as possible.

ii.Two-finger technique. If the rescuer is alone or unable to physically encircle the victim's chest, chest com­ pression is done using 2 fingers. Two fingers of one hand areplacedverticallyover the sternumjust below the intermammary line (between the two nipples) ensuring that thefingersare not over xiphoid process. One hand may be placed under the infant supporting the body and head and the other hand performs the compression.

Chest compressions in children (l-8 yr age) The heel of one hand should be placed over lower half of sternum avoiding pressure over xiphoid with fingers lifted above thechestwalltopreventcompressionofribcage (Fig. 27.1). Rescuer should position himself vertically above the victim's chest.

Chestcompression for largechildren and those above 8-yr-old The two-hand method for chest compression is used to achieve an adequate depth of compression. This is achieved by placing heel of one hand over the lower half of sternum and heel of the other hand over the first hand, interlocking the fingers of both hands with fingers lifted above the chest wall.

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Pediatric Critical Care -

Opening the airway The tongue is the most common cause of respiratory obstruction in unresponsive children and all the measures are targeted to lift the tongue away from the posterior pharynx to keep the airway patent.

i.Head tilt chin lift maneuver. If the victim is unrespon­ sive, the airway is opened by tilting the head back andlifting the chin (Fig. 27.2). One hand is placed over the child's forehead and the head is gently tilted back. At the same time the fingers of the other hand are placed on the lower jaw to lift the chin to open the airway. This maneuver should not be used if there is suspicion of trauma to head and/or neck.

Fig. 27.1: Chest compression in a child

External chest compression in children and infants should always be accompanied by rescue breathing. Ventilations are relatively less important during the first minute of CPR for victims of sudden arrhythmia induced cardiac arrest than they are after asphyxia-induced arrest, but even in asphyxial arrest, a minute ventilation that is lower than normal is likely to maintain an adequate ventilation-perfusion ratio because cardiac output and therefore, pulmonary blood flow produced by chest compressions is quite low. The lay rescuers should use a 30:2compression-ventilationratio for all (infant, childand adult)victims. Foronehealthcareprovider,thecompression­ ventilation ratio should be 30:2 for all age groups. For two rescuers, the compression-ventilation ratio should be 30:2 for all adult CPR and 15:2 compression ventilation ratio for infant and child up to the start of puberty. When advanced airway (trachealtube) is in situ, the compression should not be interrupted for ventilation.

The victim should be reassessed after 2 min. If signs of spontaneous circulation have reappeared, chest com­ pression should be stoppedand only ventilation continued till return of adequate spontaneous breathing.

Airway

Infants and children are at higher risk of having respira­ tory obstruction and failure due to the following reasons: smaller size of upper airway in comparison toadults,large size of tonguein relation to the size of oropharynx, smaller and compliant subglottic area prone for collapse and/or obstruction, relatively compliant chest wall and rib cage, and limited oxygen reserve.

Positioning the victim If the child is unresponsive but breathing or signs of life present, the child should be placed ona hard surface with face up or in supineposition. Ifhead or necktrauma is suspected, head and torso should be moved as a unit and the neck immobilized.

Fig. 27.2: Head tilt chin lift maneuver

ii.Jaw thrust. Two or three fingers are placed under each sideoflowerjawatitsangletoliftthejawupwardsand outwards (Fig.27.3). Ifthismethodis unsuccessful,the head may be extendedslightlyand anotherattempt is made. This method should be used in all victims with blunt trauma, craniofacial injury, and those having GlasgowComaScalescore of lessthan 8. This method is no longer recommended for the lay rescuer because it is difficult tolearnandperform, is often not effective and may cause spinal movement.

Foreign body airway obstruction. If this is suspected, one should open the mouth and look for the foreign body. If seen, it should be carefully removed under vision. If the victim is an infant who is responsive and has hadfeatures of airway obstruction, back slaps and chest thrusts should be performed till the foreign body comes out or till the infant becomes unresponsive (see Chapter 28). Similarly, if the victim is an older child or adolescent, abdominal thrusts can be given by standing behind the victim till the foreign body is expelled out or till the patient becomes unresponsive. Ifsucha victim becomes unresponsive, CPR should be initiated with an additional maneuver of checking the airway for the foreign body after giving the chest compressions and before breaths are given.

Fig. 27.3: Opening the airway with jaw thrust

After opening of child's airway, one should check for breathing. Periodic gasping, also calledagonalgasps, is not breathing. If the patient ishaving effective spontaneous breathing with no evidence of trauma, the child should be turned to recovery position which helps in maintaining airway patency and prevents aspiration (Fig.27.4).

Bag and mask ventilation This remains the preferred technique for emergency ventilation during the initial steps of resuscitation. Self-inflating bags are available in pediatric and adult sizes.Flow-inflating bags need oxygen flow for inflation and can be used in the hospital setup. For term neonates, infants and children <8 yr of age, ventilation bags of minimum volume 450-500 ml should be used to deliver adequate amount of tidal volume. Neonatal size bags (250 ml) may be useful for preterm neonates. Regardless of the size of ventilation bag, adequate amount of tidal volume should be used to cause

visible chest rise. Excessive expansion may compromise cardiac output, increase the chances of regurgitation by distending stomach and increase the chances of air leak. In patients with head injury or cardiac arrest, excessive ventilation may adversely affect neurological outcome.

The self-inflating bag delivers only room air unless it is connected to an oxygensource. Pediatric bag-valve device without any reservoir, if connected to an oxygen inflow of 10 1/min, delivers 30-80% of oxygen to the patient. If used with a reservoir, it may deliver 60-95% of oxygen at an oxygen inflow of 15 1/min.

Pediatric Advanced Life Support

Pediatric advanced life support (PALS) refers to the assess­ ment and support of pulmonary and circulatory function in the period before, during and after cardiorespiratory arrest.PALS targets the prevention of causes of arrest and early detection and treatment of cardiopulmonary compromise and arrest in critically ill or injured child.

Components of PALS

•Basic life support (BLS), as discussed above

•Use of equipments and techniques to establish and maintain effective oxygenation, ventilation and per­ fusion

•Clinical and ECG monitoring along with arrhythmia detection and management

•Establishing and maintaining vascular access

•Identification and treatment of reversible causes of cardiopulmonary arrest

•Emergency treatment of patients with cardiac and respiratory arrest

•Treating patients with trauma, shock, respiratory failure or other pre-arrest conditions.

Adjuncts for Airway and Ventilation

Oxygenshould begiventoallseriouslyillorinjured child­ ren with respiratory insufficiency, shock and trauma. During mouth-to-mouth rescue breathings, 16-17% oxy­ gen is delivered with alveolar oxygen pressure of 80 mm Hg, and optimal external chestcompressionsprovide only a fraction of cardiac output, resulting in reduced tissue perfusionandoxygen delivery. Ventilation-perfusionmis­ match during CPR and underlying respiratory conditions causes right to left shunting resulting in reduced oxyge­ nation.

Oxygen can be administered by facemask, nasal cannula, pharyngeal mask, laryngeal mask and endo­ tracheal tube with ventilation. All fluids from patients should be treated as potentially infectious and standard universal precautions should be followed.

Endotrachea/ Intubation

Fig. 27.4: Rescue breathing in a child

If used properly, this is the most effective and reliable method of ventilation. The advantages of endotracheal intubation are that it (i) ensures adequate ventilation;

(ii)reduces risk of aspiration of gastric contents;

(iii)inspiratory time and peak inspiratory pressure can be controlled; (iv) suction can be done to keep airway patent; and (v) positive end-expiratory pressure can be provided. The disadvantages of endotracheal intubation over bag and mask ventilation are that (i) a skilled person is required for the intubation and (ii) it is associated with complications like hypoxia, cardiac arrest or injury to airway during the procedure. Hence, it is recommended that bag and mask ventilation be continued in infants and children who require ventilatory support in the out of hospital setting, when transport time is short or when an expert is not available for intubation. The indications for endotracheal intubation are listed in Table 27.4.

Table 27.4: Indications for endotracheal intubation

Excessive work of breathing leading to fatigue Apnea or poor respiratory effort

Functional or anatomical airway obstruction

Needforhigh peakinspiratory and/or positive end-expiratory pressure for effective gas exchange

Lack of airway protective reflexes Prolonged cardiopulmonary resuscitation

The airway in a child is more compliant with a relatively largetongueandanteriorlyplacedglottis. As the ubglottic area is the narrowest part of the airway, uncuffed endo­ trachealtubes are usedin children below 8 yrofage. In certain circumstances (e.g. poor lung compliance, high airway resistance, or a large glottic air leak) a cuffed tube may be preferred. If cuffedtrachealtubesareused,thecuff pressure should not exceed 20 cm water. An appropriate sized endotracheal tube should beused (Table 27.5). Beyond 1 yr of age, the size of the tracheal tube is estimated as follows:

Tracheal tube size (in mm)= (Age in yr/4) + 4.

In general, tubes 0.5 mm smaller and 0.5 mm larger than the estimated size should be available for use. The size of suction catheter is usually twice the internal diameter of the tracheal tube in mm, i.e. 8 Fr suction catheter for tracheal tube of size 4 mm.

Procedure Endotracheal intubation should always be preceded by supplemental oxygen and the attempt at intubation should not exceed approximately 20 seconds, as hypoxia created during prolonged intubation attempts increases morbidity. The procedure should be aborted if

Table 27.5: Sizes of endotracheal tube and suction catheters in infants

Pediatric Critical Care -

bradycardia (rate below 60 per minute), deterioration in hemodynamic status, change in color (sudden pallor or cyanosis) or fall in oxygen saturation are noted. Assisted ventilation should be continued by bag-mask ventilation with supplemental oxygen until the patient's condition improves. In special circumstances, like acute respiratory distress syndrome (ARDS) requiring high peak inspiratory pressure that cannot be maintained by bag-mask venti­ lation alone, intubation should be considered despite presence of bradycardia or cyanosis.

A straight blade laryngoscope is used for infants and curved ones for children beyond 1 2- yr of age. The blade tip is passed over the epiglottis followed by blade traction to lift the base of tongue and epiglottis anteriorly, exposing the glottis. Endotracheal intubation should be attempted after visualizing the glottic opening. Confirmation of intubation is done by detection of exhaled CO2 using colori­ metric detection or capnography. While intubating, the black mark on the tracheal tube (vocal guide) should be kept at the level of vocal cords to place the tube in proper position. It is recommended that the tube placement should be confirmed by looking for the symmetrical chest rise bilaterally and checking for equal air entry on both sides by auscultation at the axillae. Auscultation over upper abdomen is required to rule out esophageal intubation. Other markers of proper endotracheal tube placement are improving heart rate, color, perfusion and improving oxygen saturation. The position of the endotracheal tube should be confirmed by chest radiograph.

The depth of insertion of the endotracheal tube is approximately three times the inner diameter of the tube used. In newborns the depth of insertion depends on the birth weight, and is calculated as:

Depth of insertion (cm)= birthweight + 6

In children above 2 yr of age, the depth of insertion of endotracheal tube can be calculated as:

Depth of insertion (in cm)= (age in yr/2) + 12

Establishing and Maintaining Vascular Access

Intravenous access. During CPR, the preferred access is the largest, most easily accessible vein, cannulating which does not require interruption of the resuscitation. Central venous lines provide secure access to the circulation, rapid action and high peak drug levels and permit adminis­ tration of drugs that might injure the peripheral sites if extravasated, such as vasopressors, hypertonic solutions like sodium bicarbonate or calcium gluconate. Femoral vein is the safestandeasiest to access. Subclavianveinsmay be considered. Agents with short half-life such as vaso­ pressors, adrenaline and adenosine act better if given through central venous access. Catheter lengths of 5 cm in infants, 8 cm in young children and 12 cm in older children are usually suitable.

lntraosseous access. Intraosseous access should be tried in all patients irrespective of age if the central or peripheral

venous access is not achieved. The usual site for intra­ osseous access is the upper end of the tibial, medial to tibial tuberosity (see Chapter 28). Other sites where the intraosseouslines can be securedin children are the distal end of femur, lower end of the tibia above the medial malleous and anterior superior iliac spine. Drugs like adrenaline, adenosine or vasopressors can be transfused by this route. It can be used to take samples for chemical analysis, blood grouping and cross matching.

Tracheal administration. Tracheal route is not the preferred route of administration of drugs even in emergency situa­ tion. If intravenous or intraosseus assess is not established in time, the tracheal route may be used for administration oflipidsoluble drugslikelidocaine, epinephrine,atropine, naloxone.Nonlipidsolubledrugs (e.g.sodiumbicarbonate and calcium) may injure the airway and should not be administered via the endotracheal route.

Fluid Therapy

Earlyrestorationof the circulating blood volume is impor­ tant to prevent progression to refractory shock or cardiac arrest. Volume expansion is best achieved with isotonic crystalloid fluids, such as Ringer's lactate or normal saline. Blood replacement is indicated in patients with severe hemorrhagic shock who remain hypotensive even after

the infusion of 40-60 ml/kg of crystalloid. Dextrose solutions should not be used for initial resuscitation as they do not expand the intravascular volume effectively and may cause hyperglycemia leading toosmoticdiuresis, setting a vicious cycle of polyuria and hypovolemia. Recommendationscannot bemadeabouttheuseofcolloid solutions in fluid resuscitation of infants andchildren due to lack ofstudies.Hypoglycemia, ifsuspectedor documen­ ted, should be managed readily with intravenous glucose with measures to prevent recurrence.

Drugs used for Cardiac Arrest and Resuscitation

Table 27.6showsthe drugs used commonly during resus­ citation.

Arrhythmias

Most arrhythmias are the consequences of hypoxemia, acidosis and hypotension. However, children with myo­ carditis, cardiomyopathy and after cardiac surgery are at increased risk of primary arrhythmias. Drugs in thera­ peuticortoxicdosescanalsocausearrhythmia.About10% of pediatricpatients with cardiac arrest have ventricular fibrillation or pulselessventricular tachycardia.

Bradyarrhythmias. Hypoxemia, hypothermia, acidosis, hypotension and hypoglycemia depress sinus node func-

Tachycardia, pupil dilatation

Bradycardia; flush the line with saline before and after infusing; avoid extravasation

Avoid hyperglycemia