Anaesthesia in a patient with subarachanoidal haemorrhage and high oxygen affinity haemoglobinopathy (HB york): case report

BACKGROUND: Approximately 90 haemoglobinopathies have been identified that result in abnormally high oxygen affinity. One of these is haemoglobinopathy York (HbY), first described in 1976. HbY causes an extreme leftward shift of the oxygen dissociation curve with the P50 value changing to 12.5 - 15.5 mmHg (normal value 26.7 mmHg), indicating that approximately half of the haemoglobin is not available as oxygen carrier. Patients with haemoglobinopathies with increased oxygen affinity could suffer from the risk developing ischaemic complications due to a lack of functional oxygen carriers. This is, to best of our knowledge, the first case report on a patient with HbY published in connection with anesthesia. CASE PRESENTATION: A 42-year-old female with a severe headache and Glasgow coma scale (GCS) of 15 was admitted to the neurosurgical intensive care unit with a ruptured, right sided ICA aneurysm with consecutive subarachnoid haemorrhage [Fisher III, World Federation of Neurosurgical Societies (WFNS) I)]. The medical history of the patient included an erythrocytosis (Hb 17.5 g/dl) on the base of a high-oxygen-affinity haemoglobinopathy, called Hb York (HbY). With no time available to take special preoperative precautions, rapid blood loss occurred during the first attempt to clip the aneurysm. General transfusion procedures, according to the guidelines based on haemoglobin and haematocrit values, could not be applied due to the uncertainty in the oxygen carrier reduction. To maintain tissue oxygen supply, clinical indicators of ischaemia were instead utilized to gauge the appropriate required blood products, crystalloids and colloids replacements. Despite this, the patient survived the neurosurgical intervention without any neurological deficit. CONCLUSIONS: Family members of patients with HbY (and other haemoglobinopathies with increased oxygen affinity) should undergo clinical assessment, particularly if they are polycythaemic. If the diagnosis of HbY is confirmed, they should carry an "emergency anaesthesiology card" in order to avert perioperative risks arising from their "hidden" anemia.