Homologous blood transfusion is not required in surgery for adolescent idiopathic scoliosis

Intraoperative red blood cell salvage in posterior spinal fusions for idiopathic scoliosis: identifying potential criteria for selective use

STUDY DESIGN

Retrospective.

OBJECTIVES

Evaluate the role and effectiveness of ICS in primary posterior spinal fusion (PSF) for idiopathic scoliosis (IS). Intraoperative cell salvage (ICS) minimizes blood loss and need for allogeneic transfusions. However, it adds substantial charges ($800-1200 US) and may be of less clinical benefit in some PSF for IS.

MATERIALS AND METHODS

This was a single-hospital, retrospective analysis of 178 consecutive IS cases (10-18 years of age) who underwent primary PSF by a single pediatric spine surgeon.

RESULTS

Overall, 41% of cases received a mean 167 cc of ICS blood, after a mean EBL of 528 mL (range 200-1800 mL). No blood was returned in 59% of cases, with a mean EBL of 293 mL (range 75-700 mL). Only 6.5% of the entire cohort received > / = 250 cc via ICS, after a mean EBL of 773 mL. A positive correlation exists between EBL and vertebral levels fused, preoperative major Cobb angle, and length of anesthesia (p < 0.001). ICS may be more efficacious at an inflection point of 12 vertebral fusion levels, preoperative major Cobb angles > / = 55°, anesthesia exposure > / = 6 h, and with use of posterior column osteotomies (PCOs) (p < 0.05). In addition, lack of tranexamic acid use lead to greater EBL (p < 0.0001) and ICS volumes (p = 0.008).

CONCLUSION

The use of ICS in IS patients undergoing PSF resulted in the return of > / = 250 cc of ICS blood (similar volume to one allogeneic unit) in only 6.5% of cases. Charges for ICS set-up and processing of one bowl of ICS is much higher than for one allogeneic unit ($1200 vs. $462 US), hence transfusing lower volumes of autologous ICS blood is not cost-effective for all PSF for IS.

LEVEL OF EVIDENCE

IV; Therapeutic studies.

The efficacy and safety of intraoperative acute normovolaemic haemodilution in complex spine surgery in a private surgical facility in Ghana

Objectives

To assess the safety and clinical benefits of intraoperative acute normovolaemic haemodilution (ANH) in complex spine surgery.

Design

Prospective comparative cohort study.

Setting

A private orthopaedic hospital in Ghana.

Patients

Seventy-six patients who underwent complex spine deformity surgery.

Interventions

Patients were randomly assigned to two groups. 45 patients to the acute normovolaemic haemodilution (ANH) or Group 1 and 31patients to the non-ANH or Group 2. Following anesthetic administration and before incision, autologous blood was collected from patients in Group1 and was reinfused during/shortly after surgery while patients in Group2 were transfused with compatible allogeneic blood intraoperatively.

Main Outcome Measures

Changes in haemodynamic parameters and incidence of allogeneic transfusions and related complications.

Results

The mean age (years), gender ratio, deformity size and aetiology, fusion levels, and operative times were similar in both groups. Blood loss (ml) of patients in groups 1 and 2 were 1583ml± 830.48 vs 1623ml ± 681.34, p=0.82, respectively. The rate of allogeneic blood transfusion in groups 1 and 2 were 71% vs 80.65%, p=0.88, respectively. Haemoglobin levels (g/dL) in groups 1 and 2 were comparable in both groups at Post-operative Day (POD) 0 and POD 1. Incidence of minor allogeneic transfusion reaction was 1/45 vs 1/31, p=0.80, group-1 and group-2, respectively.

Conclusion

Acute normovolaemic haemodilution can be safely performed in complex spine surgery in underserved regions. However, its use does not obviate allogeneic transfusion in patients with complex spine deformities in whom large volumes of blood loss is expected.

Funding

None declared.

Reducing Allogenic Blood Transfusion in Pediatric Scoliosis Surgery:: Reporting 15 Years of a Multidisciplinary, Evidence-Based Quality Improvement Project

STUDY DESIGN

Retrospective review of prospectively collected spinal surgery and transfusion databases.

OBJECTIVES

To evaluate the efficacy of a care pathway developed at our institution since 2003 with a focus on reducing the need for blood transfusions in children undergoing scoliosis correction surgery. The care pathway includes nurse-led clinics facilitating preoperative hemoglobin optimization, intraoperative cell salvage, the use of tranexamic acid, and a transfusion criteria awareness program.

METHODS

Retrospective review of our institution's prospectively recorded spinal surgery and transfusion databases including all cases of scoliosis surgery in patients 18 years and younger between 2001 and 2015.

RESULTS

A total of 1039 procedures were included in the analysis. Overall, 24.4% of patients received a transfusion. The proportion of patients transfused was 89.2% in 2001-2003, 39.6% in 2004-2006, 16.5% in 2007-2009, 15.6% in 2010-2012, and 20.1% in 2013-2015. The volume of blood products transfused in those undergoing transfusion was 9.1 units in 2001-2003, 4.8 units in 2004-2006, 5.0 units in 2007-2009, 2.3 units in 2010-2012, and 2.1 units in 2013-2015. A multivariate logistic regression demonstrated adjusted odds ratios for the probability of receiving any transfusion of 5.45 (95% confidence interval 3.62-8.11) for patients with neuromuscular diagnoses and 11.17 (5.02-24.86) for those undergoing combined anterior and posterior surgical approach.

CONCLUSIONS

We have demonstrated over a 15-year period that the introduction of a multifaceted, multidisciplinary pathway can dramatically and sustainably reduce the need for blood transfusions and their attendant risks in pediatric scoliosis surgery. This data lends weight to the adoption of such a care pathway in pediatric scoliosis surgery.

Acute Normovolemic Hemodilution in Spinal Deformity Surgery

Objective  To prospectively compare the clinical and laboratorial aspects of patients undergoing spine deformity surgery, using the acute normovolemic hemodilution technique with tranexamic acid, versus a control group with tranexamic acid alone, and to evaluate the influence of hemodilution in intraoperative bleeding and the need for homologous transfusion.

Materials and Methods  Comparative prospective study with patients aged between 12 and 65 years undergoing spine deformity surgery with the acute normovolemic hemodilution technique associated with tranexamic acid versus a control group to which only tranexamic acid (15 mg/kg) was administered. Laboratorial exams were performed and analyzed in three different moments.

Results  A total of 30 patients were included in the present study: 17 in the hemodilution group, and 13 in the control group. The mean duration of the surgery in the hemodilution group was longer. The number of levels submitted to surgery ranged from 7 to 16 in the hemodilution group, and from 4 to 13 in the control group. Osteotomy, predominantly of the posterior kind, was performed in 20 patients. There was more intraoperative bleeding in the control group. All patients were stable during the procedures. Only 6 participants needed homologous blood transfusion, mostly from the control group ( p  > 0.05).

Conclusion  There was no significant difference between the two groups regarding the need for blood transfusion and intraoperative bleeding. The severity of the deformity was the main determinant for homologous blood transfusion.

Comparison of the Coagulation Profile of Adolescent Idiopathic Scoliosis Patients Undergoing Posterior Spinal Fusion With and Without Tranexamic Acid

STUDY DESIGN

Prospective, observational cohort study.

OBJECTIVE

To improve the understanding of coagulation and bleeding mechanisms during spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

Fibrinolysis is the mechanism of bleeding for adolescent idiopathic scoliosis undergoing posterior spinal fusion. Antifibrinolytics have become popular; however, literature to support their use remains mixed. The mechanism of action has not been demonstrated.

METHODS

The coagulation profile of 88 adolescent idiopathic scoliosis patients undergoing posterior spinal fusion was analyzed. Standard coagulation laboratory investigations and thromboelastograms were drawn hourly through the case. Fifty-eight patients received no antifibrinolytic, whereas 30 patients received tranexamic acid by standardized protocol. The coagulation parameters, estimated blood loss, and transfusion requirements were compared in the two groups.

RESULTS

The two cohorts had no differences in demographic or surgical characteristics. Mean age was 13.6 years, 83% were female, a mean of 11.1 levels were fused, and the mean duration of surgery was 209 minutes. The tranexamic acid cohort did not demonstrate a decrease in blood loss. The transfusion rate, however, dropped from 47% in the non-tranexamic acid cohort to 23% in the tranexamic acid cohort (p = .03). Standard coagulation parameters did not differ between the groups. Fibrinolysis was diminished in the tranexamic acid cohort as measured by a Fibrinolysis score (mean maximum value 2.0 without tranexamic acid vs. 0.7 with tranexamic acid, p < .0001) and the lysis percent at 30 minutes by thromboelastogram (elevated to 3.9% without tranexamic acid vs. 1.2% with tranexamic acid at the 3-hour mark, p = .05).

CONCLUSIONS

This study provides confirmation of antifibrinolytic activity during posterior spinal fusion for adolescent idiopathic scoliosis. The presented data of fibrinolysis are proposed as standard measurements for future work on controlling blood loss during scoliosis surgery.

LEVEL OF EVIDENCE

Level 2, prospective comparative study.

Development of Consensus Based Best Practice Guidelines for Perioperative Management of Blood Loss in Patients Undergoing Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis

STUDY DESIGN

Delphi process with multiple iterative rounds using a nominal group technique.

OBJECTIVE

The aim of this study was to use expert opinion to achieve consensus on various methods for minimizing blood loss in patients undergoing posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

BACKGROUND DATA

Perioperative blood loss management represents a critical component of safely performing PSF in children with AIS. Little consensus exists on ways to mitigate excessive blood loss after PSF.

METHODS

An expert panel composed of 21 pediatric spine surgeons was selected. Using the Delphi process and iterative rounds using a nominal group technique, participants in this panel were presented with a detailed literature review and asked to voice opinion collectively during three rounds of voting. Agreement >80% was considered consensus. Interventions without consensus were discussed and revised, if feasible.

RESULTS

Consensus was reached to support 21 best practice guideline measures for perioperative management of blood loss in patients undergoing PSF for AIS. Areas included preoperative assessment and preparation, intraoperative strategies to decrease blood loss, and postoperative transfusion indications.

CONCLUSION

We present a consensus-based best practice guideline consisting of 21 recommendations for strategies to minimize and manage blood loss during PSF. This can serve to reduce variability in practice in this area, help develop hospital specific protocols, and guide future research.

The efficacy of bipolar sealer on blood loss in spine surgery: a meta-analysis

OBJECTIVE

The purpose of this meta-analysis of randomized controlled trials (RCTs) and non-RCTs was to gather data to evaluate the efficacy and safety of bipolar sealer versus standard electrocautery in the management of spinal disease.

METHODS

The electronic databases including Embase, PubMed and Cochrane library were searched to identify relevant studies published from the time of the establishment of these databases up to January 2017. The primary outcomes were total blood loss, requirement of transfusion (rate and amount), and operation time. The secondary outcomes were length of hospital stay and postoperative wound infection. Data analysis was conducted with RevMan 5.3 software.

RESULTS

A total of five studies involving 500 patients (261 patients in the BS group and 239 in the control group) were included in the meta-analysis. The pooled results revealed that application of bipolar sealer could decrease the total blood loss in spine surgery [WMD = -467.49, 95% CI (685.47 to -249.51); p < 0.05; I ² = 91%]. Compared with standard electrocautery, bipolar sealer was associated with lower rates of need for transfusion [OR = 0.30, 95% CI (0.16-0.55), p < 0.05; I ² = 0%]. In addition, patients in the BS group were likely to receive less amount of blood transfusion compared with patients in the control group[WMD = -0.73, 95% CI (-1.37 to -0.09), p < 0.05; I ² = 76%]. The mean operative time was shorter in the BS groups compared with the control group [SMD = -0.36, 95% CI (-0.60 to -0.13), p < 0.05; I ² = 0%]. There was no significant difference in terms of length of hospital stay [WMD = -0.73, 95% CI (-1.96 to 0.51), p = 0.25; I ² = 67%] and postoperative wound infection [OR = 0.88, 95% CI (0.31-2.48), p = 0.81; I ² = 0.0%] between both groups.

CONCLUSIONS

The available evidence suggests that bipolar sealer is superior to standard electrocautery with less blood loss, shorter operation time and less transfusion requirement. There is no significant difference between both groups regarding length of hospitalization and wound infection. Hence, bipolar sealer is recommended in spine surgery. Because of the limitation of our study, more well-designed RCTs with large sample are required to provide further evidence of safety and efficacy between bipolar sealer and standard electrocautery in the treatment of spinal disease.

Coagulation Profile of Patients with Adolescent Idiopathic Scoliosis Undergoing Posterior Spinal Fusion

BACKGROUND

Blood loss and transfusion requirements during posterior spinal fusion for adolescent idiopathic scoliosis remain a concern. The mechanism of bleeding in these patients is poorly characterized. Thromboelastography is a comprehensive test of a patient's coagulation system commonly used in cardiac surgical procedures. It has not been well studied for use in patients with adolescent idiopathic scoliosis.

METHODS

A prospective, observational study of the coagulation profile of patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion is presented. Healthy patients with adolescent idiopathic scoliosis without a bleeding abnormality were analyzed during posterior spinal fusion. Standard coagulation laboratory and thromboelastogram measures were obtained at the time of the incision and at 1-hour intervals during the surgical procedure. Laboratory values were analyzed in relation to outcomes such as bleeding, transfusion, and a fibrinolysis score.

RESULTS

Fifty-eight patients were observed. Eighty-one percent of patients were female, the mean age was 13.5 years, a mean of 11.1 levels were fused, the median estimated blood loss was 645 mL, and 47% of patients received blood products. Overall, laboratory values remained stable throughout the surgical procedure. Mild increases in prothrombin time and partial thromboplastin time were observed, and platelets remained stable. From thromboelastogram analysis, an acceleration of clot formation (decreased reaction time) and a slight increase in clot lysis (increased lysis percentage at 30 minutes) were observed. A fibrinolysis score compiled from the presence of fibrin degradation products, the presence of D-dimers, and increased prothrombin time rose steadily over surgical time. The fibrinolysis score was predictive of both transfusion and greater estimated blood loss per level.

CONCLUSIONS

The stress of posterior spinal fusion induces a hypercoagulable state in patients with adolescent idiopathic scoliosis. Over the first 2 hours of a surgical procedure, varying degrees of fibrinolysis develop. Platelets and coagulation factors are not depleted. Our data support the use of antifibrinolytic therapy for patients with adolescent idiopathic scoliosis.

Antifibrinolytic agents for reducing blood loss in scoliosis surgery in children

BACKGROUND

This is an updated version of the original Cochrane review first published in 2008. Scoliosis surgery is often associated with substantial blood loss and potentially detrimental effects in children. Antifibrinolytic agents are often used to reduce perioperative blood loss. Clinical trials have evaluated their efficacy in children undergoing surgical correction of scoliosis, but no systematic review has been published. This review was first published in 2008 and was updated in 2016.

OBJECTIVES

To assess the efficacy and safety of aprotinin, tranexamic acid and aminocaproic acid in reducing blood loss and transfusion requirements in children undergoing surgery for correction of idiopathic or secondary scoliosis.

SEARCH METHODS

We ran the search for the previous review in June 2007. For this updated version, we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 7), MEDLINE (1946 to August week 1 2015), Embase (1947 to 2015 week 38), Latin American Caribbean Health Sciences Literature (LILACS) (1982 to 14 August 2015), Database of Abstracts of Reviews of Effects (DARE; 2015, Issue 2) and reference lists of reviews and retrieved articles for randomized controlled trials in any language. We also checked the clinical trial registry at http://www.clinicaltrials.gov on 8 October 2015.

SELECTION CRITERIA

We included blinded and unblinded randomized controlled trials (RCTs) that evaluated the effects of antifibrinolytics on perioperative blood loss in children 18 years of age or younger and undergoing scoliosis surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. The primary outcome was total blood loss (intraoperative and postoperative combined). Secondary efficacy outcomes were the number of participants receiving blood transfusion (both autologous and allogeneic) or receiving allogeneic blood transfusion alone, and the total amount of blood transfused. Safety outcomes included the number of deaths, the number of participants reporting any adverse event or a serious adverse event, withdrawals due to adverse events and the number of participants experiencing a specific adverse event (i.e. renal insufficiency, hypersensitivity or thrombosis). We assessed methodological risk of bias for each included study and employed the GRADE approach to assess the overall quality of the evidence.

MAIN RESULTS

We included three new studies (201 participants) in this updated review, for a total of nine studies (455 participants). All but one study employed placebo as the control group intervention. For the primary outcome, antifibrinolytic drugs decreased the amount of perioperative blood loss by 427 mL (95% confidence interval (CI) 251 to 603 mL), for a reduction of over 20% versus placebo. We rated the quality of evidence for our primary outcome as low on the basis of unclear risk of bias for several domains in most studies and the small total number of participants.For secondary outcomes, fewer participants receiving antifibrinolytic drugs received transfusion (allogeneic or autologous) versus those receiving placebo (risk ratio (RR) 0.65, 95% CI 0.50 to 0.85, number needed to treat to prevent one additional harmful outcome (NNTp) 5; very low-quality evidence). Only two studies specifically evaluated the number of participants transfused with only allogeneic blood (risk difference (RD) -0.15, 95% CI -0.26 to -0.03, NNTp 7; very low-quality evidence). Antifibrinolytic drugs decreased the volume of blood transfused by 327 mL (95% CI -186 to -469 mL; low-quality evidence).No study reported deaths in active or control groups. Data were insufficient to allow performance of meta-analysis for any safety outcome. No studies adequately described their methods in assessing safety. The only adverse event of note occurred in one study, when three participants in the placebo group developed postoperative deep vein thrombosis.

AUTHORS' CONCLUSIONS

Since the last published version of this review (2008), we have found three new studies. Additional evidence shows that antifibrinolytics reduce the requirement for both autologous and allogeneic blood transfusion. Limited evidence of low to very low quality supports the use of antifibrinolytic drugs for reducing blood loss and decreasing the risk, and volume, of transfusion in children undergoing scoliosis surgery. Evidence is insufficient to support the use of a particular agent, although tranexamic acid may be preferred, given its widespread availability. The optimal dose regimen for any of these three agents has not been established. Although adverse events appear to occur infrequently, evidence is insufficient to confirm the safety of these agents, particularly for rare but potentially catastrophic events. No long-term safety data are available.

Eliminating the use of allogeneic blood products in adolescent idiopathic scoliosis surgery

PURPOSE

The aim of this study was to compare transfusion requirements in patients before and after the introduction of tranexamic acid as standard in patients undergoing spinal surgery for idiopathic scoliosis in a national orthopaedic hospital.

METHODS

A retrospective chart review of 56 idiopathic scoliosis patients who underwent posterior spinal instrumentation and fusion between 2009 and 2013 at our institution. Preoperative, intraoperative, and postoperative data were measured.

RESULTS

Patients who received tranexamic acid as standard (n = 31) showed a trend towards a decrease in transfusion requirements compared with those who received no tranexamic acid (n = 25). These patients had a statistically significant decrease in operative time (223 vs 188 min, p = 0.005), and estimated intraoperative blood loss was reduced by nearly 50% in the tranexamic acid group. They also had an associated reduced decrease in haemoglobin between preoperative and postoperative levels (4 vs 5 g/dL, p = 0.01).

CONCLUSIONS

Since February 2012, no patient has required intraoperative or postoperative allogeneic blood product transfusion in this hospital. The routine use of antifibrinolytic medications in patients undergoing surgery for adolescent idiopathic scoliosis has effectively eliminated the need for allogeneic blood products.

The pattern of blood loss in adolescent idiopathic scoliosis

BACKGROUND CONTEXT

Previous studies have shown that modern intraoperative blood-saving techniques dramatically reduce the allogeneic transfusion requirements in surgery for adolescent idiopathic scoliosis (AIS). No studies have looked at the pattern of postoperative hemoglobin (Hb) in AIS patients undergoing corrective spinal surgery and correlated this with the timing of allogeneic transfusion.

PURPOSE

To describe the pattern of perioperative blood loss in instrumented surgery for AIS. We look at the recommendations regarding an ideal preoperative Hb, the need for preoperative cross-matching, and the timing of postoperative Hb analysis.

STUDY DESIGN

This was a retrospective case series. Surgeries were performed by one of four substantive pediatric spinal surgeons within a single regional center over a 3-year period.

PATIENT SAMPLE

A consecutive series of 86 patients who underwent posterior instrumented fusion for AIS were included: 10 males and 76 females. Mean age was 14 years (range 10-17 years). All patients had posterior instrumented fusion using various blood-saving techniques (eg, cell-saver). All patients were cross-matched preoperatively, and our transfusion trigger value (TTV) was 7 g/dL.

OUTCOME MEASURES

Hemoglobin level was the outcome measure. Hemoglobin readings were obtained preoperatively, within 2 hours of surgery, and daily up to 5 days after surgery. This physiologic measure was assessed using routine blood sampling techniques and standardized laboratory processing.

METHODS

Patient predictor variables (demographic and surgical) were assessed for association with Hb levels in a hierarchical model, with repeated Hb readings at the lower level being clustered within an individual patient at the upper level of the structure. The variation of Hb levels within individuals was compared with mean levels in different individuals via the variance partition coefficient of the model structure.

RESULTS

No patients required intraoperative allogeneic transfusion. Only four patients (4.65%) received allogeneic transfusion, all within 2 days of surgery. A clinically important drop in Hb occurred within the first 2 postoperative days, rising thereafter. The average postoperative drop in Hb was 4.1 g/dL. Young males had lower postoperative Hb values. Neither the preoperative curve magnitude (Cobb angle of major curve) nor the number of vertebrae/levels fused significantly affected the blood loss.

CONCLUSIONS

We recommend setting a minimum preoperative Hb value that is 5 g/dL higher than your TTV. Because no patients required an intraoperative transfusion when using modern blood-saving techniques, preoperative cross-matching is unnecessary and potentially wasteful of blood reserves. Hemoglobin analysis beyond the second postoperative day is unnecessary unless clinically indicated.

Blood Loss Reduction During Surgical Correction of Adolescent Idiopathic Scoliosis Utilizing an Ultrasonic Bone Scalpel

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVES

To evaluate blood loss associated with posterior spinal fusion in adolescent idiopathic scoliosis patients performed with and without the use of an ultrasonic bone scalpel (UBS).

SUMMARY OF BACKGROUND INFORMATION

After using an ultrasonic-powered bone-cutting device with recent Food and Drug Administration approval for use in the spine, the authors perceived a reduction in bone bleeding associated with the cut boney surfaces.

METHODS

The first 20 patients with adolescent idiopathic scoliosis who underwent posterior spinal fusion using the UBS by a single surgeon were compared with 2 control groups: 1) the 20 most recent prior cases of the same surgeon before beginning use of the bone scalpel; and 2) 20 cases of the same surgeon before using the bone scalpel matched based on Cobb angle magnitudes. Both cases and controls had Ponte-type posterior apical releases; none had an anterior procedure. Patient demographic and surgical data were analyzed using analysis of variance (p < .05).

RESULTS

Preoperatively, the UBS group was similar to both control groups in terms of primary and secondary curve magnitudes, number of levels fused, number of levels with Ponte release, antifibrinolytic use, and patient age (p > .05). The UBS group had significantly less estimated blood loss (EBL) (550 ± 359 mL), Cell Saver blood transfused (94 ± 146 mL), and EBL per level fused (48 ± 30 mL) than the most recent controls (EBL: 799 ± 376 mL; Cell Saver: 184 ± 122 mL; EBL/level fused: 72 ± 28 mL) and Cobb-matched controls (EBL: 886 ± 383 mL; Cell Saver: 198 ± 115 mL; EBL/level fused: 78 ± 30 mL) (p < .05). Surgical times were equivalent and there were no dural tears in any group.

CONCLUSIONS

The use of an ultrasonic bone scalpel to perform the bone cuts associated with facetectomies and apical Ponte-type posterior releases resulted in significantly less bleeding compared with cuts made with standard osteotomes and rongeurs, limiting overall blood loss by 30% to 40%.

Predictors of blood transfusion in patients undergoing elective surgery for degenerative conditions of the spine

BACKGROUND

The requirement of blood in the surgery of degenerative conditions of lumbar spine is around 10 %. Preoperative autologous blood donation is an effective method that is used in surgeries with an important blood loss. This is an expensive method because of the great number of predonated blood units not used in the postoperative period (around 70 % in our practice).

OBJECTIVE

To know the risk factors associated with transfusion in the postoperative period in patients who undergo surgeries of degenerative conditions of the lumbar spine.

METHODS

We designed a retrospective study of 142 cases of patients operated for degenerative conditions of the lumbar spine (not including simple disk hernia or adult degenerative scoliosis).

RESULTS

Female sex, age >60 years, preoperative ASA score 3 and preoperative hemoglobin ≤136 g/L are the risk factors related to the need of blood transfusion in the postoperative period. After application of a statistical study, female sex and preoperative ASA score 3 were the most important variables to explain transfusional risk. A woman with ASA score 3 has a 61 % foretold probability to be transfused in the postoperative period, while a man with ASA < 3, only 1.1 %. For this reason, application of this method to patients with these risk factors is more cost-effective.

CONCLUSIONS

Females, ASA 3, preoperative hemoglobin ≤136 g/L and age older than 60 years increase the risk to be transfused in the postoperative period for degenerative conditions of the spine.

Antifibrinolytic agents for reducing blood loss in scoliosis surgery in children

BACKGROUND

Scoliosis surgery is often associated with substantial blood loss and potential detrimental effects in children. Antifibrinolytic agents are often used to reduce perioperative blood loss. Clinical trials have evaluated their effect in children undergoing surgical correction of scoliosis but no systematic review has been published. We performed a systematic review on the efficacy and safety of antifibrinolytic drugs in children undergoing scoliosis surgery.

OBJECTIVES

To assess the efficacy and safety of aprotinin, tranexamic acid and aminocaproic acid in reducing blood loss and transfusion requirements in children undergoing scoliosis surgery.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2007, Issue 3), OVID MEDLINE (1950 to September 3rd 2007), LILACS (1992 to June 20th 2007) and EMBASE (1980 to July 23rd 2007). We also searched conference proceedings from 2003 to 2007 and the clinicaltrials.gov registry. No language restriction was applied.

SELECTION CRITERIA

We included blinded or unblinded randomized controlled trials that evaluated the effect of antifibrinolytics on perioperative blood loss in children that were 18 years of age or younger and undergoing scoliosis surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently performed the data extraction. Primary outcomes were mortality and number of patients transfused. Secondary outcomes were number of patients transfused with allogeneic blood, amount of total blood transfused, total blood loss and adverse events. To assess heterogeneity we used the I(2) test and for the quantitative analysis we used a fixed-effect model.

MAIN RESULTS

Six studies fulfilled the inclusion criteria. The total number of participants was 254, of whom 127 were allocated to placebo and 127 to antifibrinolytic drugs. Aprotinin, tranexamic acid and aminocaproic acid were evaluated in two studies each. All studies had placebo as the control group intervention. There were no deaths or any serious adverse events in any study, in either the active or the control group. The risk of being transfused was similar in patients receiving antifibrinolytic drugs or placebo. Antifibrinolytics drugs decreased the amount of blood transfused by 327 ml (95% CI -469.04 to -185.78) and the amount of blood loss by 427 ml (95% CI -602.51 to -250.56). There was no indication of publication bias, however, we cannot rule it out due to the small number of studies included.

AUTHORS' CONCLUSIONS

The effect of antifibrinolytic drugs on mortality could not be assessed. Antifibrinolytic drugs reduced blood loss and the amount of blood transfused in children undergoing scoliosis surgery; however, their effect on the number of children requiring blood transfusion remains unclear. Aprotinin, tranexamic acid and aminocaproic acid seem to be similarly effective.