Bombay Blood Group for Pediatric Cardiac Surgery in the Era of a Pandemic: Newer Challenges Call for Desperate Measures!

ABSTRACT

Bombay blood group is one of the rarest blood types with a prevalence of 1 per 10,000 population in India. Children and adults of this blood group can receive autologous blood or blood from an individual with a Bombay phenotype only. Children with grown-up uncorrected cyanotic heart disease are associated with a high risk of perioperative hemorrhagic diathesis and may require multiple blood transfusions. Arrangement of adequate Bombay blood group units for pediatric cardiac surgery is a unique challenge. The COVID-19 pandemic brought about additional difficulties in the procurement of blood components due to donor hostility. Despite the associated risks, pre-operative multi-session autologous blood harvest under monitored anesthesia care was planned in a 16-year-old child and four units of autologous blood were harvested and preserved for performing total correction surgery.

INTRODUCTION

Bombay blood group is a rare autosomal recessive phenotype with an estimated prevalence of 1 in 10,000 in India and 1 in 1,000,0000 outside of India.[1] These patients can receive only autologous blood or Bombay phenotype red blood cells. Children with such rare blood groups scheduled to undergo pediatric cardiac surgery require careful planning for managing blood component therapy.[2] Grown-up children with uncorrected cyanotic heart disease suffer from hemorrhagic diathesis and arrangement of adequate cross-matched blood products is a prerequisite for total correction surgery.[3]

During the COVID-19 pandemic, because of the government-imposed restrictions on travel and apprehensions associated with acquiring the infection, voluntary blood donations were minimized. A multi-session autologous blood harvest was successfully performed in a 16-year-old child with recurrent cyanotic spells and four units of autologous blood were harvested and preserved for performing total correction surgery due to a lack of available voluntary donors. Challenges were imposed in this particular case due to a risky autologous harvest which was successfully overcome because of a strategized peri-operative plan which has been subsequently described.

CASE REPORT

A 16-year-old girl from a low socio-economic stratum, with a poor nutritional status, weighing 38.5 kg and having a body mass index of 17.1 kg/m², presented with recurrent episodes of cyanotic spells and squatting episodes. Two dimension echocardiography revealed tetralogy of fallot (TOF), large maligned sub-aortic ventricular septal defect with bidirectional shunt, severe infundibular and valvular PS with <50% aortic overriding, and good left ventricular function. The right atrium and ventricle were dilated and significant major aortopulmonary collaterals were noted. During routine pre-operative testing, her blood sample was found to be incompatible with all O-positive blood. After performing reverse grouping with O-pooled red cells and forward typing with anti-H lectin, she was found to have a Bombay blood group (Oh). Four units of cross-matched blood was deemed essential for the major surgery. Bombay blood group red blood cell units were unavailable at the hospital blood center or with other blood centers in the city. All available family members were screened but were found to be non-compatible with the bombay blood group. The blood center team then initiated communications with many of the listed bombay blood group voluntary donors across the country and with many non-governmental organizations in other cities for aid. Most of the listed voluntary donors cited the COVID-19 pandemic as the reason behind their apprehension to travel and visit the hospital for donation. Since the surgery could not be delayed further, it was then decided to harvest autologous blood from the child. The feasibility of performing an intraoperative autologous donation was discussed with the blood center team but was deemed an unreliable plan if the child deteriorated and did not tolerate the large volume of acute normovolemic hemodilution. Oral iron and folic acid supplementation as per her body weight were continued and the child was thus planned for four sessions of autologous blood harvest under monitored anesthesia care (MAC) in the daycare unit on an outpatient basis. Oxygen saturation, electrocardiogram, and non-invasive blood pressure were monitored at each autologous blood harvest session. Difficulties were anticipated in autologous blood harvest due to high baseline hemoglobin of 22.1 gm/dL which could cause high resistance and stasis in the tubing leading to clot formation in the tubing or the autologous blood bag. Clear liquids were fully allowed till the time of performing of harvest and the child was pre-hydrated with 10 ml/kg of crystalloid fluids over 30 to 45 min before performing the autologous harvest to ensure there was no element of dehydration. The height of the recliner was elevated to maximum height in order to enhance gravity-mediated drainage. Blood volume equivalent to 10% of total body weight (~350 ml) was collected in each sitting, which was simultaneously replaced with an equivalent volume of crystalloids. The child was monitored for 4 hours and was discharged after ensuring adequate oral intake and after passing urine. Four such sessions were performed over a month at a regular interval of seven days. A complete blood count was performed before every session and a hemoglobin values of 21.9, 19.6, and 19.5 gm/dL was recorded at the second, third and fourth week respectively. The child was then posted for surgery with four units of autologous blood at hand.

Intraoperative measures of blood conservation included the use of antifibrinolytics like injection tranexamic acid at a loading dose of 10 mg/kg followed by 1 mg/kg/h infusion for 24 hours after surgery. The intra-operative autologous donation was performed and two additional units of autologous blood were collected and stored, before the administration of heparin for cardiopulmonary bypass (CPB) with an aim to achieve hemoglobin of 10 gm/dL on the pump. Injection heparin was administered at a dose of 4 mg/kg to target an activated clotting time of 480 s throughout the CPB run. Retrograde autologous priming of arterial and venous cardio-pulmonary bypass cannulae was done to minimize hemodilution upon initiation of CPB. Intra-cardiac repair with pulmonary valve replacement and right ventricular outflow tract reconstruction using glutaraldehyde fixed autologous pericardium was performed under mild hypothermia and the child was weaned off cardio-pulmonary bypass with minimal inotropic support of dobutamine infusion at 5 mcg/kg/min. The heparin administered was reversed with an injection of protamine at a 1:1 dose. Cell saver was made available for the need of harvesting mediastinal blood loss. Meticulous hemostasis, adequate rewarming and slow re-administration of two units of harvested autologous blood after protamine administration ensured minimal post-operative drainage. Hemoglobin concentration on post-operative day one was 15.2 gm/dL and on post-operative day two was 14.3 gm/dL. The child was successfully extubated after 4 h of mechanical ventilation. The ICU stay was uneventful and the child was discharged after one week of an uneventful hospital stay.

DISCUSSION

Bombay blood group phenotype is a rare autosomal recessive blood type with only a sporadic prevalence in the community. Management of blood products for such patients is an uphill task for the blood center at any hospital as these patients can receive only autologous or Bombay phenotype red blood cells.[4] Owing to the small shelf life of all blood products, maintenance of an inventory of such blood products is impossible and thus, most tertiary care hospitals and private blood centers and non-government organization-aided blood banks to rely on a directory of individuals diagnosed with Bombay blood group who are willing to undergo voluntary blood donation. Up on the diagnosis of this rare blood group in our case, numerous futile attempts were made at contacting voluntary Bombay blood group donors across north India. The fear and apprehension of visiting a hospital during the pandemic and the restrictions on travel due to a lockdown imposed by the government were their major cited reasons for the lack of willingness to donate blood.[5]

TOF is a cyanotic congenital heart disease that ideally requires corrective surgery at an early age. Delayed surgery due to late presentation of such congenital heart anomalies such as TOF in developing countries is associated with an additional risk of hemorrhagic diathesis due to impaired clot retraction secondary to reduced synthesis of clotting factors, subclinical chronic compensated disseminated intravascular coagulation, increased volume of packed red cells (hematocrit) and/or deranged platelet aggregation.[3] Availability of cross-matched blood and blood products under a massive transfusion protocol is thus a prerequisite for such patients undergoing cardiac surgery. As voluntary donors could not be arranged for the child in the wake of the pandemic despite sincere efforts on behalf of the hospital, family, and various non-governmental organizations, it was decided by the hospital transfusion committee to sequentially harvest autologous blood from the child and to carefully preserve it for the definitive surgery.

Children have a low circulating blood volume and are at high risk of hypovolemia if a conventional autologous donation is performed. The high likelihood of precipitation of a tet-spell due to dehydration and hypovolemia in an intensely cyanotic child was avoided in our case by performing the procedure under MAC and ensuring a careful pre-hydration followed by a simultaneous exchange with crystalloids. The surgery was subsequently done putting into practice all blood conservation strategies described above, to minimize post-operative bleeding as it bears a crucial impact on patient outcome. Minimal chest drainage was a reassurance to the entire team and ensured no massive transfusion was required.

To conclude, the presence of an extremely rare blood group imposes difficulties in the procurement of blood components for any challenging surgery, more so in situations where voluntary donations are minimized. Four serial autologous blood collections preoperatively in a child with severe cyanotic heart disease were performed for the first time in a case to avoid any further delay in the definitive surgery. This strategy should however only be used as a rescue plan to address the adversities faced due to a pandemic, lack of available voluntary blood donors, or for extremely rare blood groups only. The successful management of this case emphasizes the fact that meticulous pre-operative planning and patient optimization are necessary to transform adversities into success stories.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.