Modified Lund concept versus cerebral perfusion pressure-targeted therapy: a randomised controlled study in patients with secondary brain ischaemia

Purpose

Secondary brain ischaemia (SBI) usually develops after aneurysmal subarachnoid haemorrhage (SAH) and severe traumatic brain injury (TBI). Current approaches to managing these conditions are based either on intracranial pressure-targeted therapy (ICP-targeted) with cerebral microdialysis (CM) monitoring according to the modified Lund concept or cerebral perfusion pressure-targeted therapy (CPP-targeted). We present a prospective, randomised controlled study comparing relative effectiveness of the two management strategies.

Methods

Sixty comatose operated patients with SBI following aneurysmal SAH and severe TBI were randomised into ICP-targeted therapy with CM monitoring and CPP-targeted therapy groups. Mortality rates in both groups were calculated and tissue biochemical signs of cerebral ischaemia were analysed using CM. Measured CM data were related to outcome (Glasgow Outcome Scale GOS] score 1, 2 and 3 for poor outcome or GOS score 4 and 5 for good outcome).

Results

Patients treated with ICP-targeted therapy with CM monitoring had significantly lower mortality rate as compared with those treated with CPP-targeted therapy (P = 0.03). Patients monitored with CM who had poor outcome had lower mean values of glucose and higher mean values of glycerol and lactate/pyruvate ratio as compared with those who had good outcome (glucose: P = 0.003; glycerol: P = 0.02; lactate/pyruvate ratio: P = 0.01). There was no difference in the mortality outcome between aneurysmal SAH and severe TBI in the two groups (P = 0.28 for ICP-targeted therapy with CM monitoring, P = 0.36 for CPP-targeted therapy). Also, there were no differences in the CM values between patients with aneurysmal SAH and severe TBI who underwent ICP-targeted therapy (glucose: P = 0.23; glycerol: P = 0.41; lactate/pyruvate ratio: P = 0.40).

Conclusion

The modified Lund concept, directed at bedside real-time monitoring of brain biochemistry by CM showed better results compared to CPP-targeted therapy in the treatment of comatose patients sustaining SBI after aneurysmal SAH and severe TBI.