• • • • • • Demographics the history? What wouldyouliketoelicitfrom 1 differential diagnoses? What areyourimmediate 3 2 movements)? culty breathing,generaldistress, unusualquietnessor colour change? – isitlaboured,erraticornormal? (peripheral orcentral)? Find outmoreabouttheblueness: Presenting complaint disease whentheductclosesafter3–7days. most likelytopresentinthefi Arethereanyassociatedsymptoms(i.e. crying,diffi Whatwasthebabydoingattimeshenoticed Whathasthemothernotedaboutherchild’s breathing Howsuddenlydiditcomeon? Where hasthemothernoticedcolourchange Exactlyhowoldisthisbaby?Congenitalproblemsare

‘he hasstartedturningblue’. Mrs SmithhasbroughtherbabytoA&Ebecauseshesays • • • • • • • • • • • Respiratory causes Lack ofrespiratorydrive Congenital cyanoticheartdisease Case 4 Drugs. CNS infection. CongenitalCNSmalformation. Seizure disorder. Otherrarercyanoticdefects. Transpositionofthegreatarteries. TetralogyofFallot. Acquired obstruction. Congenital obstruction. Acquiredrespiratoryproblem. Congenitalrespiratorydisorder. : The bluebaby : rst month,cyanoticheart : - • • • • Systems enquiryandpastmedicalhistory 1 Review yourdifferentials • • • • • fever, sleepiness? development? stained liquor? Obstetric history problems? Family history Arethereanyothersignsofinfection– poorfeeding, Do theparentshaveanyconcernsaboutchild’s Hasthechildhadanybreathingproblemsbefore? Doesthechildhaveanymedicalconditions? Werethereanyproblemswithantenatalscans? Wasthechildbornatterm? Were thereanyproblemsatbirth,e.g.meconium- Aretheparentsrelated? Arethereotherfamilymemberswithcongenitalheart

history. Allthescanswerenormalinpregnancy. neither she,norherhusband,hasanyrelevantpastmedical but doesnotseemtobestruggling. interested today.Heisbreathingalittlefasterthannormal, did notseemtoimprovewhenhecalmeddown. Mrs Smithputthisdowntohimcryingatthetimebutit turning bluearoundthemouthacoupleofhoursago. term, andeverythinghadseemedfi Baby Smithisonly3daysold.Hewasbornathome, • Respiratory causes cause, butwillnotexcludeit. normal workofbreathingis against arespiratory in onethisyoung.Investigations arerequired.The tell respiratorycausesfromcardiac causesofcyanosis

Mrs Smithwaswellthroughoutthepregnancyand He wasfeedingwellatthebreast,buthasnotseemed Congenital respiratorydisorder : ne until hestarted : Itcanbediffi cult to cult 29

PART 2: CASES 30 Part 2: Cases

• Acquired respiratory disorder: Baby Smith may have On examination, there is deep peripheral and central a chest infection, or bronchiolitis, but the lack of respi- cyanosis. The baby is tachypnoeic with minimally increased ratory symptoms makes this unlikely. work of breathing. There are no apparent obstructions in • Congenital obstruction: Upper airway obstruction is the mouth or pharynx. unlikely without stridor (see Case 13, p. 67, for further The HR is 165, capillary refi ll time 2–3 s, BP 65/35 and the discussion of upper airway obstruction). femorals are palpable. The chest is moving well and clear to • Acquired obstruction: This might be caused by a ausculation and percussion. foreign body. However, baby Smith is too young to put things in his mouth. This is, therefore, an unlikely What investigations will you perform? diagnosis, but it is not out of the question (see Case • Arterial blood gas. 23, p. 106). He could also have an airway infection, • Chest X-ray. such as croup, but again this is unlikely at this age. • Nitrogen washout/hyperoxic test. 2 Congenital cyanotic heart disease: • ECG. • Tetralogy of Fallot: This can present soon after birth • Echocardiography. in extremely severe cases. However, the majority of children present with hypercyanotic ‘spells’ during the Some of the results are back: fi rst year of life. These episodes, usually accompanied by crying, distress and apparent air hunger, are PaO2 3.2 kPa characteristic. PaCO2 4.5 kPa • Transposition of the great arteries (TGA): In this dis- pH 7.15 − order, the pulmonary artery is connected to the left BE 7.1 ventricle and the aorta to the right ventricle. This gives The chest radiograph is also back. The ECG is normal. rise to two separate parallel circulatory systems. In fetal PART 2: CASES life and the fi rst few days ex utero the natural shunts What do you make of the blood results created by the foramen ovale and the ductus arteriosus and chest fi lm? allow mixing of the two circuits. When the ductus closes, There is a metabolic acidosis. This is due to lactic acidosis the infant cannot get oxygenated blood to the body. resulting from poor tissue oxygenation, despite reason- able cardiac output. The chest fi lm (Fig. 8), demonstrates What will you do now? the classic ‘egg on its side’ cardiac shadow. This is an emergency. Cyanosis indicates a potentially life-threatening lack of oxygenated blood. You must assess the baby and decide what degree of resuscitation is required. Check the airway for obstruction, and assess breathing and circulation. Check pulse rate and perfusion. Further examination must be rapid – what key things will you look for? • General observations: ᭺ Cyanosis – central or peripheral? ᭺ Level of arousal – is this baby’s conscious level decreased? If it is, it implies a critical level of hypoxia. • Close assessment of the respiratory system: ᭺ Assess work of breathing. ᭺ Percuss and auscultate the lung fi elds. • Close assessment of the cardiovascular system: ᭺ Check capillary return. ᭺ Auscultation for murmurs. ᭺ Feel the femoral arteries. ᭺ Check BP. Figure 8 Baby Smith’s chest radiograph. Case 4 31

What is the nitrogen washout test and • The Rashkind septostomy is a temporary measure to what do you expect it to show? allow mixing of the two circulations by removing the This test differentiates cardiac from respiratory causes of atrial septum. This can be done by catheter in an ICU. cyanosis. The child is placed in 100% O2 for 10 min. This • The treatment of choice is the arterial switch opera- maximally oxygenates the pulmonary circulation. There- tion. If successful, this has the fewest long-term compli- fore, if the origin of the problem is respiratory, the desat- cations because it is closest to the natural anatomical uration should be ameliorated (unless extremely severe) structure. The arteries are transected and replaced (note as the extra alveolar oxygen overcomes the diffusion that the coronary arteries also have to be replaced). This problem in the lungs. If the child is still cyanotic by the must be done within the fi rst 2 weeks of life, before end of the test there must be a right-to-left cardiac shunt, pressure changes in the heart begin to detrimentally as the increased oxygen is unable to get into the systemic affect the myocardium (the left ventricle regresses blood because of abnormal plumbing. due to attachment to the low pressure pulmonary circulation).

Baby Smith’s 10 min blood gas showed a PaO2 of 7 kPa (an • Sometimes a ‘Mustard’ or ‘Senning’ repair is usually

arterial PaO2 of less than 20 kPa is considered to indicate a done at about 6 months of age. The aim here is to create high likelihood of cyanotic heart disease). a longer term solution by using a baffl e to redirect caval blood through the mitral valve (and therefore the left What do you expect the ventricle and pulmonary artery). Pulmonary return is echocardiography to show? redirected to the tricuspid valve. This tends to result in The echo would show the anatomical cause of the heart failure in the long term because the right ventricle problem. However, neonatal echo is only available in does not have the blood supply to cope with the work of specialist centres. You will have to stabilize the child supplying the high pressure systemic circulation. before you can get an echo. PART 2: CASES What is the prognosis? What is the management plan? The arterial switch operation has a mortality of about 5% It is imperative to maintain some link between the right but success rates are improving all the time. If it is suc- and left circulations. Cyanosis is developing now because cessful, the prognosis is good. Since these techniques the ductus arteriosus is in the process of closing. This is were developed fairly recently, it is diffi cult to say what a ‘duct-dependent’ circulation. To maintain patency of the very long-term complications may be. There is a risk the duct you administer a continuous prostaglandin E2 of residual pulmonary stenosis, which may lead to right infusion (in extreme cases the intraosseus route is accept- heart failure. able), which relaxes the ductus smooth muscle. You continue supportive measures, concentrating on: Comments • Temperature. • The body is not as concerned about hypoxia as it is • Correcting the acidosis. about acidosis or hypercapnia, causing tachypnoea and • Setting up a dextrose infusion to maintain blood increasing tidal volume. Disease in the lungs also directly glucose. stimulates the respiratory centre. The effect of this is that Call the cardiology team to arrange transfer to a pae- cyanosis caused by a cardiac malformation produces few diatric cardiology centre. respiratory signs, but that from a respiratory cause pro- duces fl orid signs. What is the defi nitive treatment? • VACTERL: The traditional VATER acronym (vertebral First the child must have an anatomical diagnosis. anomalies, anal malformations, tracheo-oesophageal The echo confi rms transposition of the great arteries. fi stula and radial and renal abnormalities) is sometimes The aorta and pulmonary arteries are in parallel with the extended to include cardiac and limb deformity. This is aorta in front of the pulmonary artery. Fortunately for a well recognized group of anomalies. Three or more baby Smith, ultrasound also shows a large ventricular must be present in order to apply this term. septal defect. Septal defects are often associated with TGA • Tetralogy of Fallot, which includes: and make the presentation less severe. ᭺ An overriding aorta. Surgical correction must be performed. ᭺ Right ventricular outfl ow tract obstruction. 32 Part 2: Cases

᭺ Ventricular septal defect. • An ECG at birth shows right axis deviation and right ᭺ Right ventricular hypertrophy. ventricular hypertrophy in all babies. Normally this • This is often associated with syndromes (such as changes over the fi rst 5 years to an adult pattern. With Noonan’s, Down’s, maternal phenylketonuria). The RV hypertrophy this does not happen. The ECG is not tetrad results in mixing of oxygenated and deoxygenated usually helpful in the diagnosis of anatomical heart blood, a reduction in pressure in the pulmonary artery disease unless conduction is affected. and elevated pressure in the right ventricle (Figs 9 and • In Fallot’s, the CXR may show a characteristic 10). The older child with an uncorrected defect may be ‘boot-shaped’ heart. Defi nitive diagnosis is on seen to adopt a characteristic squatting position. This echocardiography. obstructs left ventricular output, increasing LV pressure • Without treatment most die before their teens. With and forcing more blood through the obstructed RV surgery, 95% survive into the third decade. Surgical outfl ow tract. repair is in two stages. An early palliative procedure is the Blalock–Taussig shunt (look for the scar behind the left or right scapula). This joins the subclavian artery to the pulmonary artery. When the child is older, fi nal recon- structive surgery can be undertaken. • Incidence rates: Overall, eight in 1000 live born babies will have a heart defect. Most of these are asymptomatic. Many of the septal defects close in their own time. ᭺ Ventricular septal defect (Fig. 11) 33% ᭺ Pulmonary stenosis 8% ᭺ Persistent ductus arteriosus 12% ᭺ Atrial septal defect 6% PART 2: CASES ᭺ Coarctation of the aorta 6% ᭺ Aortic stenosis 5% ᭺ Tetralogy of Fallot 6% ᭺ Transposition of great arteries 5%

Further reading and information British Heart Foundation, http://www.heartstats.org. Figure 9 Radiograph from a child with Terralogy of Fallot. Note The British Heart Foundation has useful information prominent right ventricle and pulmonary oligaemia. on the incidences of congenial heart disease.

Mixed oxygenated and deoxygenated blood in aorta Ductus: flow may be L l R here

LA Overriding aorta RA Constricted pulmonary outflow Overriding aorta allows R l L LV blood flow

RV

Figure 10 Tetralogy of Fallot. Case 4 33

Fully oxygenated blood in aorta

Excessive blood flow in pulmonary artery LA High LA pressure leads to pulmonary oedema RA LV overloaded by excessive blood flow

L R shunt as RV pressure is LV lower than LV pressure

RV RA pressure is raised as a Figure 11 Ventricular septal defect. LA, left atrium; LV, result of higher RV pressure left ventricle; RA, right atrium; RV, right ventricle.

Tanner K. Cardiovascular malformations among preterm KEY POINTS infants. Paediatrics 2005; 116 (6): 833–8. Treasure T. Congenital heart disease. British Medical • Cyanosis is cardiac or respiratory in origin. Journal 2004; 328: 594–5. • The child’s age, and the presence or absence of

associated symptoms, are useful in directing the PART 2: CASES diagnostic process. CASE REVIEW • Cardiac abnormalities are relatively common (eight in 1000 live births). Baby Smith is 3 days old when his mother notices that • Prostaglandins are used in the immediate management he seems to be becoming increasingly cyanosed, although of patients with duct-dependant circulation (to maintain patency of the ductus arteriosus). he has little respiratory diffi culty. A cardiac diagnosis • Surgical correction is the defi nitive treatment for both rather than a respiratory one is suggested by a minimal transposition of the great arteries and tetralogy of increment in PaO2 when put into 100% oxygen. His chest Fallot. radiograph shows no respiratory disease and he has an abnormal cardiac silhouette. He is sent to a paediatric cardiac centre for a diagnostic echocardiogram and corrective surgery. Despite the diffi culty and risks of the procedures he will undergo, his outcome is likely to be good.