in 1971 , fontan and baudet first described a palliative surgery for patients with tricuspid atresia .
it revolutionised the management of patients with complex congenital heart disease characterized by a single functional ventricle .
we describe the anaesthetic management of a 12 year - old girl who had fontan physiology and right hemiparesis , for botox injections , managed under general anaesthesia .
a 12 year - old girl weighing 41 kg was posted for botox ( botulinum ) injections and casting for spasticity of the right upper limb .
she gave history of having some heart disease since birth for which multiple operations had been done .
on going through her past medical records , it was found that she was born with complex congenital heart disease , having dextro - transposition of great arteries , double outlet right ventricle , pulmonary stenosis , and a large ventricular septal defect .
she underwent a right subclavian to right pulmonary artery shunt shortly after birth , a glenn operation at 4 months of age , and an extracardiac fontan operation ( total cavopulmonary conduit ) at 5 years of age .
computed tomography ( ct ) brain showed left middle cerebral artery ( mca ) thrombosis due to which she had developed right hemiparesis .
the hemiparesis improved gradually and she developed spasticity of the right upper and lower limbs .
she had developed pedal edema a few months earlier , due to an element of protein losing enteropathy , which was treated with diuretics and high protein diet .
she gave history of no cardiovascular ( cvs ) complaints at the time of admission , and was regular in her studies and daily activities .
she was on treatment with tablet warfarin 5 mg and tablet furosemide 20 mg once a day . on examination , she was conscious , oriented , well nourished .
she was afebrile , pulse was 82 beats / minute and regular , blood pressure was 102/66 mm hg .
investigations revealed haemoglobin of 11.2g / dl , total and differential white blood cell counts were normal .
renal function tests , serum electrolytes , liver function tests including serum proteins were within normal limits .
echo showed patent functioning cavopulmonary shunts , mild ventricular systolic dysfunction , no thrombi / vegetations .
she was advised to withhold warfarin and switch over to a low - molecular weight ( lmw ) heparin 5 days prior to surgery .
infective endocarditis prophylaxis was given with iv ceftriaxone 1 g 1 hour prior to the procedure .
it was decided to give general anaesthesia since the patient was very apprehensive and insisted on it .
patient was taken to the operation theatre , monitors were attached ( ecg , pulse oximeter , capnograph , non - invasive blood pressure monitor ) .
an infusion of lactated ringer 's solution was started and she was preloaded with around 200ml .
preoxygenation was done for 5 minutes and anaesthesia was induced with iv fentanyl 80 mcg and propofol 80 mg iv slowly and maintained with sevoflurane 0.6 - 0.8% in 50% nitrous oxide in oxygen , on spontaneous ventilation with intermittent assist .
patient received 300ml ringer 's lactate intraoperatively , and the procedure lasted 30minutes . at the end of surgery ,
once awake , responding to oral commands and stable , patient was shifted to the recovery room for monitoring .
she was shifted to the ward after an hour and had an uneventful post operative period .
prior to the development of the fontan procedure , pulmonary blood flow in patients with single ventricle and pulmonary stenosis was surgically augmented by means of systemic to pulmonary artery shunts .
these shunts improved life expectancy remarkably in the short term , but survival past the second decade remained unusual . in 1971 , fontan and baudet , and in 1973 , kreutzer et al .
it involved diverting systemic venous blood from the right atrium to the pulmonary arteries , thus bypassing the right ventricle .
it was then used for treating a number of complex congenital heart lesions with a single effective ventricle . in fontan physiology , systemic venous blood from the great veins
oxygenated blood then drains into the left atrium and then into the single ventricle that empties into the systemic circulation .
the difference between central venous pressure and systemic ventricular end - diastolic pressure ( termed the  transpulmonary gradient  ) is the primary force promoting pulmonary blood flow and , more importantly , cardiac output .
since intravascular volume is the main determinant of central venous pressure , hypovolemia is poorly tolerated .
thus , the main determinants of the fontan circulation are systemic venous pressure and volume , pulmonary vascular resistance , cardiac rhythm and left ventricular function . a disturbance in any of these compromises the cardiac output
. complications in post - fontan surgery patients include arrythmias , thromboembolism , protein losing enteropathy , and ventricular dysfunction .
propofol , with its transient systemic vasodilatation , is usually less problematic , as long as normovolemia is maintained.etomidate , with its cardiostable property would be the best drug for induction is these patients .
hypercarbia , hypoxia , inadequate analgesia , and acidosis should be avoided as they will lead to an increase in pulmonary vascular resistance , decreased pulmonary blood flow and thus decreased cardiac output . for short procedures ,
controlled mechanical ventilation leads to increase in intrathoracic pressure which decreases venous return , in turn causing decreases pulmonary blood flow , and hence , decreases cardiac output .
epidural anaesthesia has been successfully employed in such patients.[1012 ] postoperatively , good analgesia has to be ensured . for more painful surgeries , continuous catheter techniques , epidural analgesia and patient controlled analgesia
normovolemia needs to be maintained , and hypercarbia , hypoxia and acidosis should be avoided .
 fontan procedure is a palliative surgery done for patients born with single ventricle physiology . 
 an understanding of the hemodynamic alterations in such a patient is important for successful perioperative management . 
 we have discussed the anaesthetic considerations in a 12 year - old girl with complex congenital heart disease ultimately palliated by a fontan operation , who was posted for botox injections for upper limb spasticity under general anaesthesia . 
INTRODUCTION
CASE REPORT
DISCUSSION
CONCLUSION