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General orthopaedics: L. K. Smith, D. H. Williams, and V. G. Langkamer Post-operative blood salvage with autologous retransfusion in primary total hip replacement J Bone Joint Surg Br 2007; 89-B: 1092-1097 [Abstract] [Full text] [PDF]

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Author's reply

Lindsay K. Smith   (17 October 2007)

Author's reply:

Lindsay K. Smith   (15 October 2007)

Post-operative blood salvage

K C Kong   (28 September 2007)

Post-operative blood salvage with autologous retransfusion in primary THR

Saeed Al-Naser   (13 September 2007)

Author's reply 17 October 2007
Lindsay K. Smith, Research Associate BOA Send letter to journal: Re: Author's reply Lindsay.Smith{at}waht.swest.nhs.uk Lindsay K. Smith	Sir, We thank Mr Kong for his comments and would like to respond as follows. We note the comment that blood loss is increased through use of suction drains but suggest that our study should not be used to support this view as it was not designed with volume of blood loss as an objective. We found no significant difference in mean post-operative haemoglobin levels between the two groups in our study despite differences in suction pressure. Similarly, Walmsley et al1 did not measure blood loss and did not find a significant difference in post-operative haemoglobin levels between their groups with and without a drain. Widman et al2 studied 22 patients, 12 with and 10 without a drain, and compared the volume of haematoma using erythrocyte scintigraphy. They recorded a higher number of patients in the group with a drain that required a blood transfusion but the study did not appear to be constructed to statistically analyse this outcome and the lack of a reported transfusion policy does not exclude the possibility of performance bias. We agree that there is insufficient evidence from randomised trials to support the routine use of closed suction drainage in orthopaedic surgery in general.3,4 We do, however, also agree with the 2007 Cochrane review that further randomised trials with larger patient numbers are required for different operations before definite conclusions can be made for all types of orthopaedic operations.3 We limited our study to primary hip arthroplasty and did not look at total knee arthroplasty. We hope that our study will contribute to any future analysis of this subject. L.K. Smith, Research Associate, BOA, Department of Trauma and Orthopaedic Surgery, Weston General Hospital, Weston-super-Mare, UK. 1. Walmsley PJ, Kelly MB, Hill RM, Brenkel I. A prospective, randomised, controlled trial of the use of drains in total hip arthroplasty. J Bone Joint Surg [Br] 2005;87-B:1397-1401. 2. Widman J, Jacobsson H, Larsson SA, Isacson J. No effect of drains on the postoperative hematoma volume in hip replacement surgery: a randomized study using scintigraphy. Acta Orthop Scand 2002;73:625–9. 3. Parker MJ, Livingstone V, Clifton R, McKee A. Closed suction surgical wound drainage after orthopaedic surgery. Cochrane Database Syst Rev 2007;3:CD001825. 4. Parker MJ, Roberts CP, Hay D. Closed suction drainage for hip and knee arthroplasty. A meta-analysis. J Bone Joint Surg [Am] 2004;86-A:1146-52.
Author's reply: 15 October 2007
Lindsay K. Smith, Research Associate BOA Send letter to journal: Re: Author's reply: Lindsay.Smith{at}waht.swest.nhs.uk Lindsay K. Smith	Sir, We thank Dr Al-Naser for his comments. We acknowledge the lack of a ‘no-drain’ group in this study and discussed this in our paper. With regard to drains causing ‘more harm than benefit’ we are aware that the latest Cochrane review found no statistically significant difference in the incidence of wound infection, haematoma, dehiscence or re-operations between drained and un-drained wounds.1 Walmsley et al also found no significant difference in either superficial or deep infection rates with the use of drains.2 We agree that, in the same paper, 26.4% of un-drained arthroplasties required a blood transfusion compared with 33% of those patients who received a closed vacuum drain (p = 0.042)2 and note that these figures were higher than those found in either of our study groups (21% in those with a vacuum drain and 8% in those with an autologous system (p = 0.022)). The Cochrane review also concluded that blood transfusion was required more frequently in those who received closed vacuum drains. However, by its nature, the review pooled data from patients undergoing all types of elective and emergency orthopaedic surgery including hip and knee replacement, shoulder surgery, hip fracture surgery, spinal surgery, cruciate ligament reconstruction, open meniscectomy and fracture fixation surgery. So, while they concluded that there is insufficient evidence from randomised trials to support the routine use of closed suction drainage in orthopaedic surgery, they also acknowledged that further randomised trials with larger patient numbers are required for different operations before definite conclusions can be made for all types of orthopaedic operations.1 We feel that our prospective, randomised study adds to this evidence base. Finally, the decision not to record intra-operative loss was made when designing the study. As covered in our discussion, it was felt that consistent and accurate intra-operative blood loss data could not be guaranteed in our unit. May we also refer Dr Al-Naser to the first paragraph of the methods section for the basis of our power calculation. L.K. Smith, Research Associate, BOA, Department of Trauma and Orthopaedic Surgery, Weston General Hospital, Weston-super-Mare, UK. 1. Parker MJ, Livingstone V, Clifton R, McKee A. Closed suction surgical wound drainage after orthopaedic surgery. Cochrane Database Syst Rev 2007;3:CD001825. 2. Walmsley PJ, Kelly MB, Hill RM, Brenkel I. A prospective, randomised, controlled trial of the use of drains in total hip arthroplasty. J Bone Joint Surg [Br] 2005;87-B:1397-1401.
Post-operative blood salvage 28 September 2007
K C Kong, Consultant Orthopaedic Surgeon King George Hospital, Ilford,Essex. Send letter to journal: Re: Post-operative blood salvage kck{at}doctors.org.uk K C Kong	Sir, I read this article with great interest. The authors and other researchers have confirmed that there is increased blood loss as a consequence of using suction drains.1-3 Even their results show a higher mean blood loss in group A with Medinorm vacuum drains due to slightly higher suction pressures. They claim that there is a small cost saving with the use of post-operative blood salvage. There is sufficient evidence4,5 to support the avoidance of surgical drains in total hip arthroplasty. By avoiding the use of drains, there is less blood loss and reduced use of allogeneic blood transfusions and it saves the expense of a post-operative blood salvage system. The cost saving will be substantial with no increased risks to patients if this was applied across the thousands of primary hip replacements in which post-operative drains are still used. K.C. Kong, Consultant Orthopaedic Surgeon, King George Hospital, Ilford, Essex, UK. 1. Walmsley PJ, Kelly MB, Hill RM, Brenkel I. A prospective, randomised, controlled trial of the use of drains in total hip arthroplasty. J Bone Joint Surg [Br] 2005;87-B:1397-1401. 2. Widman J, Jacobsson H, Larsson SA, Isacson J. No effect of drains on the postoperative hematoma volume in hip replacement surgery: a randomized study using scintigraphy. Acta Orthop Scand 2002;73:625–9. 3. Tsumara N, Yoshiya S, Chin T, et al. A prospective comparison of clamping the drain or post-operative salvage of blood in reducing blood loss after total knee arthroplasty. J Bone Joint Surg [Br] 2006;88-B:49-53. 4. Ritter MA, Keating EM, Faris PM. Closed wound drainage in total hip or total knee replacement. A prospective, randomized study. J Bone Joint Surg [Am] 1994;76-A:35-8. 5. Parker MJ, Roberts CP, Hay D. Closed suction drainage for hip and knee arthroplasty. A meta-analysis. J Bone Joint Surg [Am] 2004;86-A:1146-52.
Post-operative blood salvage with autologous retransfusion in primary THR 13 September 2007
Saeed Al-Naser, Senior House Officer Trauma & Orthopaedics Morriston Hospital, Swansea, UK Send letter to journal: Re: Post-operative blood salvage with autologous retransfusion in primary THR alnasersaeed{at}yahoo.co.uk Saeed Al-Naser	Sir, I read the paper by Smith et al and would like to make a few comments. First, this study is comparing two different drainage systems in total hip replacement (THR); however, recent evidence does not support the use of drains at all in elective THR. Rather, evidence suggests that drains can cause more harm than benefit in THR,1 in terms of wound infection and healing,2 mobilisation post-operatively,2,3 pain1 and length of hospital stay.2 What is important is the association between drains and transfusion rates as there is convincing evidence that drains can cause a fall in the haemoglobin level post-operatively, necessitating homologous blood transfusion.3 This means that to omit a 'no drain' group is not justifiable by the fact that this can affect blinding. And the fact that a significant number of patients had a haemoglobin level below 9 g/dl post-operatively could have been avoided if no drains had been used. Secondly, there are some limitations of the study which I think affect the outcome. As mentioned by the authors, the amount of blood loss was not recorded intra-operatively. This is achievable, and might have affected the results as it is directly related to the reduced haemoglobin level post-operatively. Finally, it is reported that the sample size was determined to test the hypothesis, however, there was no mention of a power calculation in the study which leaves this study open to type 2 errors. S. Al-Naser, Senior House Officer, Trauma and Orthopaedics, Morriston Hospital, Swansea, UK. 1. Parker MJ, Roberts CP. Closed suction wound drainage after orthopaedic surgery [abstract]. The Cochrane Collaboration of Systematic Reviews, 2006. Issue 4: CD001825. 2. Walmsley PJ, Kelly MB, Hill RM, Brenkel I. A prospective, randomised, controlled trial of the use of drains in total hip arthroplasty. J Bone Joint Surg [Br] 2005;87-B:1397-1401.