- Department of Neurosurgery, Aga Khan University, Karachi, Pakistan
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
- Department of Ophthalmology, Aga Khan University, Karachi, Pakistan
- Department of Anesthesiology, Aga Khan University, Karachi, Pakistan
Muhammad Shahzad Shamim
Department of Anesthesiology, Aga Khan University, Karachi, Pakistan
DOI:10.4103/2152-7806.120778Copyright: © 2013 Alam MM. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
How to cite this article: Alam MM, Sobani ZA, Shamim MS, Ahmad K, Minai F. Primary elective spine arthrodesis: Audit of institutional cross matched to transfused (C/T) ratio to develop blood product ordering guidelines. Surg Neurol Int 29-Oct-2013;4:
How to cite this URL: Alam MM, Sobani ZA, Shamim MS, Ahmad K, Minai F. Primary elective spine arthrodesis: Audit of institutional cross matched to transfused (C/T) ratio to develop blood product ordering guidelines. Surg Neurol Int 29-Oct-2013;4:. Available from: http://sni.wpengine.com/surgicalint_articles/primary-elective-spine-arthrodesis-audit-of-institutional-cross-matched-to-transfused-ct-ratio-to-develop-blood-product-ordering-guidelines/
Background:Currently, there are no uniform guidelines regarding the appropriate amount of blood products ordered prior to spine surgery. Here, we audited our own institution's practices along with preoperative variables that contributed to perioperative transfusion requirements for elective spinal arthrodesis.
Methods:This study utilized a single institution retrospective chart review of patients undergoing elective spinal fusion over a 2 year period. The cross matched to transfused (C/T) ratio was utilized to compare different patient groups. Sub-group multivariate analysis enabled us to identify possible predictors of transfusion for this patient population.
Results:Eighty-five patients were included in the study. Of the 292 units of packed red blood cells ordered preoperatively, only 66 were transfused (C/T ratio 4.4:1). Those undergoing arthrodesis for degenerative disease (6.9:1) or cervical spine arthrodesis (23:1) had the highest C/T ratios. Univariate analysis revealed several factors contributing to a relatively high probability of perioperative transfusions, while multivariate analysis showed that the indication for surgery was the only factor independently associated with the requirement for transfusion.
Conclusion:We found an unacceptably high C/T ratio at our institution. Based on the results of our univariate analysis, we recommend that two units packed cells to be arranged for patients with preoperative hemoglobin levels
Keywords: Arthrodesis, cross matched/transfusion ratio, elective spine arthrodesis, elective surgery, prediction of transfusion requirements
With innovations regarding the safety and efficacy of spinal arthrodesis, the numbers of complex reconstructive fusion procedures are increasing with technical advances in spine surgery, the numbers of complex spinal reconstructive procedures are increasing.[
Presently, the blood loss and transfusion requirements for patients undergoing spinal procedures are being overestimated.[
Currently there are no specific evidence-based guidelines for the appropriate amount of blood products to be ordered prior to specific spine procedures. Rather, excessive amounts of blood products are ordered due to outdated preoperative institutional or anecdotal surgeon-specific guidelines. This results in an unnecessary increased workload for the blood bank, increased cost to the patient, and waste.[
To address this issue, we introduced a new institutional cross matched to transfused (C/T) protocol at a single institution over a 2-year period. This involved auditing the C/T practices of our institution and comparing them with the literature; by analyzing the various preoperative factors that contributed to blood transfusions for patients undergoing spinal surgery/fusions, we developed a Maximum Surgical Blood Order Schedule.
A retrospective chart review of all adults undergoing elective spine arthrodesis with or without decompression at our institution was performed over a 2-year period (June 1, 2009 to June 30, 2011). Patients undergoing noninstrumented fusion, multiple surgeries, operative revisions, and tumor surgery were excluded. Surgical data included; the preoperative status of patients, indications for surgery, operative approaches, the surgical levels, the number of levels decompressed and arthrodesed, the implants used, the duration of surgery, and intraoperative complications [
A total of 95 patients underwent elective spine arthrodesis at our institution during the review period. Of these, 85 patients met the inclusion criteria; 52.94% (n = 45) of them were male and 47.05% (n = 40) were female. The mean age of study subjects was 38.8 ± 18.5 years. Of the 85 patients, 11% (n = 10) were hypertensive, 6% (n = 5) were diabetic, and 5% (n = 4) had ischemic heart disease.
The primary indication for surgery in 47.05% (n = 40) of the patients was degenerative spine disease, followed by trauma 20% (n = 17), adult idiopathic scoliosis (AIS) 15.29% (n = 13), and infections including Pott's disease 5.88% (n = 5). A total of 52.9% (n = 45) of the patients had spinal arthrodesis via a posterior approach, while the remaining patients underwent the procedure via anterior approach 31.76% (n = 27), circumferential approach 8.23% (n = 7), and lateral approach 7.05% (n = 6).
Analysis of cross matched vs. transfused ratio
The blood bank data were retrieved for 85 procedures, and were analyzed regarding the total number of packed cell units ordered for each patient vs. the total units transfused (C/T Ratio).[
Introduction of new cross matched protocols
Next, we introduced institutional protocols based on the C/T ratios found for different spinal surgical procedures. First determining the association between outcome (bloods transfusion) and the other study variables, we utilized univariate analysis (e.g. Chi-squared tests, or Fisher's Exact test) where appropriate. Variables with a P value of ≤0.2 were included in binary logistic regression model to identify independent associations with blood transfusion. A P < 0.5 was taken as statistically significant.
A total of 292 units of packed red cells were ordered preoperatively, but only 66 units were transfused; this resulted in a 4.4:1 C/T ratio. Patients undergoing elective spine arthrodesis for degenerative spine disease had the highest C/T ratio of 6.9:1 followed by 5:1 for infectious etiologies, 3:1 for AIS, and 2.7:1 for trauma. Similarly, when considering percentage of patients requiring blood transfusion 69.2% (n = 9) of patients undergoing surgery for AIS required transfusions, followed by 60%, (n = 3) for infectious indications, 52.9% (n = 9) for trauma, and 22.5% (n = 9) for degenerative spinal disease. When considering the level of spinal surgery, patients having surgery of the cervical spine had the highest C/T ratio of 23:1 followed by 5.8:1 for thoracic spine, 3.8:1 for thoracolumbar junction, and 3:1 for lumbar spine. When considering the number of patients requiring transfusion by region of spine 71.4% (n = 15) of patients undergoing thoracolumbar surgery required transfusions, followed by 66.7% (n = 4) for thoracic, 59.3% (n = 16) for lumbar, 33.3 (n = 1) for cervico-thoracic, and 10.7% (n = 3) for cervical spine.
Univariate analysis for factors associated with higher risk transfusion
In the univariate analysis, factors associated with a higher risk of blood transfusion (P ≤ 0.20) included; preoperative hemoglobin less than or equal to 9 g/dl, increased requirements for spinal trauma and AIS surgery, fusions including the thoracolumbar spine, and more than two-level decompressions and/or arthrodesed [
Spine decompression and fusion with instrumentation is now a common procedure in the treatment of various pathologies of spine, including degenerative disease, trauma, and scoliosis. However, advances in surgical and anesthetic techniques and perioperative management have significantly reduced the operative blood loss but have not eliminated operative transfusion requirements.[
Nevertheless, there are no uniform guidelines regarding the appropriate amount of blood that should be ordered prior to spinal procedures. This results in the discarding or waste of cross matched but unutilized blood, thus incurring increased operative costs while depleting a vital resource.
In our study we found that majority of the cases did not require blood transfusions and the amount of blood cross matched far exceeded the requirement. Out of 292 units of packed red cells cross matched for our cohort of 85 patients only 66 units were transfused to 39 patients, indicating that only 45.88% of patients required blood transfusions. This was indeed an eye-opener for in a developing country such as ours, where healthcare is already restricted due to financial constraints, such a large wastage of valuable resource including time, money, equipment, personnel, and storage space; carried on unnoticed daily for years. This was especially true for surgeries done for routine degenerative spine pathologies (lumbar laminectomy, microdiscectomy, cervical laminectomy, anterior cervical discectomy, etc.). These incidentally are also the most frequent elective spine cases and by and large do not require perioperative transfusions. We found the C/T ratios to be unacceptably high (22.5%, C/T ratio of 6.9:1) indicating a fundamental flaw in our blood ordering practice. An introduction of a protocol would therefore be most beneficial for this group of patients.
We also found a trend that lower regions of the spine (thoracic, thoracolumbar, lumbar) were more likely to require transfusion compared with cervical spine, which is understandable given the anatomical differences. However, even for lower spine, our C/T ratio was above the optimal 2:1 reported in literature.[
Our findings concur with that of the Torres-Claramunt et.al. study, where patients undergoing elective spinal arthrodesis have excessive amounts of blood arranged, which go unutilized.[
Our study variables were selected after a comprehensive literature review, and even though little has been published on this topic, a number of variables have been proposed to have association with increased transfusion requirements. These include low preoperative hemoglobin, history of pulmonary disease, surgery for tumors, increased number of spinal levels fused, female sex, age more than 60 years, and a preoperative ASA score of 3.[
Based on the univariate analysis, we recommend two units packed cells to be arranged for patients with preoperative hemoglobin levels <9 g/dl, trauma and AIS cases, or where more than two levels are being decompressed and/or arthrodesed. For the remaining cases, a group and hold policy should be sufficient. Obviously, these recommendations are not applicable to patients undergoing extensive surgery, and patients with preexisting coagulation disorders.
Even though our recommendations appear reasonable, our study is limited by a small sample size, a retrospective design, and a case mix representing our institutional catchment and practice trends. These findings can therefore not be generalized. Moreover, due to the small sample size, not enough numbers were present in subgroups to complete a meaningful multivariate analysis, such as that for AIS or tumor cases. We would therefore recommend a larger, prospective multicenter study to validate our recommendations.
We found unacceptably high C/T ratio at our institution, especially when arthrodesis was planned for degenerative disease or cervical spine. Based on univariate analysis, we recommend two units packed cells to be arranged for patients with preoperative hemoglobin levels <9 g/dl, trauma and AIS cases, or where more than two levels are being decompressed and/or arthrodesed. For the remaining cases, a group and hold policy should be sufficient.
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