Hachida 1995.

Study characteristics
Methods	Randomised controlled trial. Number of centres and blinding not stated
Participants	28 adult patients undergoing open heart valvular surgery (leukodepletion filter (LD) 14, control filter 14) Baseline characteristics: mean age 54 years, gender not stated, all valve surgery, no difference in pre‐operative variables (body surface area, type of cardiac disease, haemoglobin and neutrophil count). Mean pre‐operative fractional shortening <30% in both groups. Inclusion: not stated Exclusion: abnormal pre‐operative lung function (pre‐op arterial blood gases, chest x‐ray and pulmonary function)
Interventions	All patients on same CPB circuit (no detail) except for filter. Systemic cooling to 28°C Leukodepletion: Pall LG6 arterial line filter after aortic declamp Control: Pall Auto Vent‐SV filter
Outcomes	Intra‐operative: aortic cross‐clamp time, CPB time White blood cell count (WBC), CK‐MB and lipid peroxide; pre‐op, in first hour (5/15/30/45/60/pump off (min), 3, 6, 12 and 24 hrs after reperfusion. Cardiac index and percent fraction shortening pre‐ and post‐op. Catecholamine dose after surgery. Pulmonary index pre‐op, 3, 6, 12 and 24 hours after reperfusion. Chest tube drainage, blood product usage, post‐operative chest x‐rays. Post‐operative infections
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Number of patients per outcome or withdrawal and completion rates not reported
Selective reporting (reporting bias)	Low risk	All collected data reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not described
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described