Hyperhomocysteinemia and Evan's syndrome with uncal herniation for emergency splenectomy.

Hyperhomocysteinemia is a genetic disorder of metabolism and transport of amino acid, commonly present as a pro-coagulant state. Evan's syndrome is an autoimmune disorder with pancytopenia, a diagnosis of exclusion. The present report highlights the anesthetic management of a rare case, where both these clinical entities coexist. A 26-year-old male, a known case of hyperhomocyteinemia on medication for 4 years, came with a history of severe headache, blurring of vision and bleeding gums. Computerized tomography brain report showed subdural hematoma (SDH) of 16 mm with 9 mm right midline shift and on investigation had thrombocytopenia (5000 cells/cumm). Patient was diagnosed to have Evan's syndrome. Because he was refractory to the medical management, taken up for emergency splenectomy, followed by burr hole evacuation of SDH. Successful anesthetic management of the case is presented in this report.

INTRODUCTION

Hyperhomocysteinemia is a pro-coagulant state, prone for deep vein thrombosis. Diagnosed, if plasma bound and free form of homocysteine level >100 μmol/L.[1]

Evan's syndrome is an autoimmune disorder with pancytopenia, a diagnosis of exclusion. Blood examination: Thrombocytopenia, hemolytic anemia with positive Coombs test (direct/indirect) and antiglobulin test. The first line of management includes low fat diet, folic acid and steroids. Splenectomy is the second line of management.[2]

There is no reporting in the literature regarding anesthetic management of a patient diagnosed to have hyperhomocysteinemia with incidental diagnosis of Evan's syndrome subjected to emergency surgery. Here we report uneventful management of such a case.

CASE REPORT

A 26-year-old male weighing 58 kg, known case of hyperhomocystienemia on tablet warfarin for 4 years presented with severe headache (1-month), blurring of vision and bleeding gums. Pallor and petechiae were present on examination. On investigation: Hemoglobin (Hb) - 4 g%, white blood cell - 2800 cells/cumm, platelets - 5000 cells/mm3 and international normalized ratio (INR) - 2.9. Direct and indirect Coomb's test: Positive. Findings confirmed Evan's syndrome. Fundoscopic eye examination: Dense periretinal and vitreous hemorrhage. Computerized tomography (CT) brain: Left fronto temporo parietal acute on chronic subdural hematoma (SDH) of 16 mm with 9 mm right midline shift [Figure 1].

Figure 1

Preoperative computerized tomography brain showing subdural hematoma with mid line shift

In view of SDH stopped warfarin, started on tablet prednisolone and phenytoin. To optimize for SDH evacuation, platelets 25 units, five fresh frozen plasma and 3 units of packed red blood cells were transfused. Thrombocytopenia persisted (5000–6000 cells/mm3). Hb (8.2 mg %) and INR (1.1) improved. Repeat CT brain had uncal herniation. Patient had projectile vomiting with deterioration of Glasgow coma scale (GCS 13/15). Administering mannitol 20 g intravenously (IV), emergency burr hole evacuation of SDH following open splenectomy was planned.

Monitors, noninvasive blood pressure, electrocardiogram, pulse oximeter and end-tidal carbon dioxide (EtCO2) were connected. Baseline parameters were documented. Pupils were equal and reactive to light.

Preoxygenated with 100% O2 for 3 min and premedicated with: Ondansetron 4 mg, hydrocortisone 100 mg, titrated doses of midazolam up to 0.04 mg/kg and fentanyl 1 μg/kg. Induced with escalating doses of fentanyl (2 μg/kg). Intubation response suppressed with lignocaine (spray 4% [2 ml] and IV 40 mg). Airway secured with rocuronium 1.2 mg/kg. Anesthesia maintained with isoflurane and O2 in air with intermittent boluses of fentanyl and rocuronium. EtCO2 maintained between 30 and 33 mmHg. Bupivacaine (0.25%, 10 ml) infiltration along the line of incision to minimize response to surgical stimulus. The goal of anesthesia was to maintain the vital parameters (heart rate and blood pressure) ±5% from the baseline values.

Following splenectomy, 10 units of platelets were transfused to empirically raise the count to >50,000 cells/mm3 and SDH evacuated through burr hole (75–100 ml). Urine output was 0.5–1 ml/h. As intraoperative course was stable, residual neuromuscular block was reversed with glycopyrrolate 6 μg/kg and neostigmine 0.05 mg/kg. Establishing adequate tidal volume, extubated in deeper plane of anesthesia and maintained with 100% O2 till patient responded to oral commands. Postoperatively patient's GCS was 15/15. For vigilant monitoring shifted to Intensive Care Unit (ICU).

In ICU 1 unit of apheresis platelets was transfused. Repeat CT brain 24 h later showed 14 mm SDH with 7 mm midline shift with persistent uncal herniation [Figure 2]. One week later in the postoperative ward platelet count - 65,000 cells/mm3. The patient got discharged, advised medical follow-up.

Figure 2

Postoperative computerized tomography brain showing subdural hematoma with mid line shift

DISCUSSION

Normal intra cranial pressure (ICP) is 5–10 mmHg, rise up to 30–50 mmHg on coughing, takes 5–10 min to return to base line values.[3] Brain herniation occurs if ICP is >60 mmHg in chronic and >20 mmHg in acute pathologies.[4]

In our case fall or raise in ICP could have led to iatrogenic consequences such as an increase in the size of the SDH or would have precipitated brain herniation respectively.[45]

Splenectomy was the line of management to optimize the platelets count before evacuation of SDH due to persistent platelet refractoriness.[6]

The goal of anesthesiologist was to maintain the cerebral perfusion pressure (CPP) and the depth of anesthesia during the course of surgery with vigilant noninvasive monitoring[7] in view of coagulopathy.

No studies have demonstrated the superiority of any particular anesthetic agent, on the outcome of neurosurgery.[78] Antiemetic was considered in the premedication as titrated dose of fentanyl was the drug of choice for induction.

Pain, anxiety and stress induce catecholamine release, influences the base line vital parameters in unpremedicated patient. Furthermore, mask the underlying volume deficit, due to hemorrhage or mannitol induced diuresis.[7] To assess the true hemodynamic status (stress-free), titrated anxiolytic dose of midazolam (0.02–0.04 mg/kg) was administered.[89] Hypotension was optimized with fluids to maintain vital parameters ±5% from the base line values.

Thiopentone sodium, propofol and etomidate are the induction agents of choice in neurosurgery. We chose fentanyl for the following reasons: Has remarkable hemodynamic stability with little or no direct effect on ICP, with inhaled anesthetic and neuromuscular blockers, it produces balanced anesthesia and reduces minimum alveolar concentration, adding much more to cardiac stability, especially during the course of anesthesia and surgery (mask ventilation, laryngoscopy, endotracheal intubation, skin incision, and retraction, SDH evacuation and extubation).[48] Total dose of fentanyl used during anesthesia was 5 μg/kg.

Rocuronium is cardio stable. Response to laryngoscopy, intubation and skin incision was suppressed with lignocaine (spray and IV) and bupivacaine infiltration. Steroids were administered to enhance platelet survival.[6]

Anesthesia was maintained with precise isoflurane titration, having least influence on cerebral metabolic rate with no influence on cortical cerebral blood flow.[89] For smooth emergence, extubation in a deeper plane was considered.[10]

Carefully monitored postoperative in anticipation of hemodynamic instability, profound bleeding and or deterioration of GCS. Investigations were repeated to know the prognosis of the disease.

CONCLUSION

The knowledge of pathophysiology of the disease and probable perioperatively complications has a great impact on the overall outcome of the patient. Vigilant monitoring of vital parameters with titrated administration of tailor maid anesthesia for a given case maintains a delicate balance of CPP.