Clinical Study Of Drainage Clamping Time After Total Knee Arthroplasty

Objective: To analyze the clinical outcomes of four different time points of drainage clamping after total knee arthroplasty and to determine the effect on blood loss blood transfusion and postoperative complications.Methods: A prospective study involving 60 patients was performed between March 2010 and April 2011. All the patients were randomized into four groups. The drainage in the four groups was respectively clamped for 0 hour, 1 hour, 2 hours and 4 hours. At 24 hour before operation, 20 hour and 48 hour after operation, the patients'demographic details, blood loss, and haemoglobin values were recorded. The total blood loss was calculated with Gross equation. Meanwhile, the number of swollen,ecchymosis, score of pain grade, HSS of six week after operation were documented.Results: The total blood loss in the four groups was respectively 1326±434 ml, 1244±415ml, 1138±441ml and 642±258ml.The volum of blood transfution in the four groups was respectively 316±266ml, 295±230ml, 285±230ml and 230±133ml.The number of blood transfution in the four groups was respectively9,7,4,3. There were statistically differences in the haemoglobin drop , blood transfusion volume and rate in the four groups.The number of ecchymosed, in the four groups was respectively 1,2,2,8. the number of swollen in the four groups was respectively2,2,1,7. There was non-statistics difference among first three groups. The drainage clamping 4 hour group have the statistical difference with other three groups of comparisons.( There were 2 patients to present the drainage tube obstructed, although after extrudes the drainage tube many times repeatedly, and strengthens the drainage tube management, but the drainage volum obvious reduction.) Aching score among 6 hour,24 hour and 48 hour after operation,the drainage clamping 4 hour group distinctly bigger than other groups. HSS of six week after operation in the four groups was respectively 83±7,80±5, 84±5, 81±4. There was non-statistics difference among the four groups.Conclusion: The results demonstrated that drainage clamping could decrease the volume of drainage, Compare clamping 1 hour and non-clamping, clamping 2 hours could significant reduce blood loss and blood transfusion rate. compare clamping 4 hours, the number of swollen, ecchymosis, score of pain grade in clamping 2 hours was significant reduced, aching score among 6 hour ,24 hour and 48 hour after operation were lower. There was no significant difference between the 4 groups regarding, postoperative range of motion and incidence of thromboembolic events.