Evaluation of acute normovolemic hemodilution for surgical repair of craniosynostosis

Optimizing Blood Loss and Management in Craniosynostosis Surgery: A Systematic Review of Outcomes Over the Last 40 Years

Surgical correction of craniosynostosis can involve significant blood loss. Rates of allogenic blood transfusion have been reported to approach 100%. Multiple interventions have been described to reduce blood loss and transfusion requirements. The aim of this study was to analyze various approaches over the last 4 decades to optimize blood loss and management during craniosynostosis surgery.

PRISMA guidelines for systematic reviews were followed. PubMed and Cochrane database searches identified studies analyzing approaches to minimizing blood loss or transfusion rate in craniosynostosis surgery.

Primary outcomes included rate or amount of allogenic or autologous blood transfusion, estimated blood loss (EBL), postoperative hemoglobin (Hg), or hematocrit (Hct) levels. Secondary outcomes were examined when reported.

Fifty-two studies met inclusion criteria. There was marked heterogeneity regarding design, inclusion criteria, surgical intervention, and endpoints. The majority of the studies were nonrandomized and noncomparative. Four studies analyzed erythropoietin (EPO), 6 analyzed various cell-saver (CS) technologies, 18 analyzed antifibrinolytics (tranexamic acid [TXA], aminocaproic acid [ACA], and aprotinin [APO]), 8 analyzed various alternatives, and 16 analyzed multimodal pathways & protocols. Some studies analyzed multiple approaches.

Although the majority of studies reviewed represent level III/IV evidence, several high-quality level I studies were identified and included. Level I evidence supported an improvement in blood outcomes by utilizing EPO, CS, and TXA, individually or in concert with one another. Thus, this review suggests that a multi-prong approach may be the most effective means to optimize blood loss and transfusion outcomes in craniosynostosis surgery.

Association of tranexamic acid with decreased blood loss in patients undergoing laminectomy and fusion with posterior instrumentation: a systematic review and meta-analysis

OBJECTIVE

Tranexamic acid (TXA) is an antifibrinolytic agent associated with reduced blood loss and mortality in a wide range of procedures, including spine surgery, traumatic brain injury, and craniosynostosis. Despite this wide use, the safety and efficacy of TXA in spine surgery has been considered controversial due to a relative scarcity of literature and lack of statistical power in reported studies. However, if TXA can be shown to reduce blood loss in laminectomy with fusion and posterior instrumentation, more surgeons may include it in their armamentarium. The authors aimed to conduct an up-to-date systematic review and meta-analysis of the efficacy of TXA in reducing blood loss in laminectomy and fusion with posterior instrumentation.

METHODS

A systematic review and meta-analysis, abiding by PRISMA guidelines, was performed by searching the databases of PubMed, Web of Science, and Cochrane. These platforms were queried for all studies reporting the use of TXA in laminectomy and fusion with posterior instrumentation. Variables retrieved included patient demographics, surgical indications, involved spinal levels, type of laminectomy performed, TXA administration dose, TXA route of administration, operative duration, blood loss, blood transfusion rate, postoperative hemoglobin level, and perioperative complications. Heterogeneity across studies was evaluated using a chi-square test, Cochran's Q test, and I2 test performed with R statistical programming software.

RESULTS

A total of 7 articles were included in the qualitative study, while 6 articles featuring 411 patients underwent statistical analysis. The most common route of administration for TXA was intravenous with 15 mg/kg administered preoperatively. After the beginning of surgery, TXA administration patterns were varied among studies. Blood transfusions were increased in non-TXA cohorts compared to TXA cohorts. Patients administered TXA demonstrated a significant reduction in blood loss (mean difference -218.44 mL; 95% CI -379.34 to -57.53; p = 0.018). TXA administration was not associated with statistically significant reductions in operative durations. There were no adverse events reported in either the TXA or non-TXA patient cohorts.

CONCLUSIONS

TXA can significantly reduce perioperative blood loss in cervical, thoracic, and lumbar laminectomy and fusion procedures, while demonstrating a minimal complication profile.

Impact of multidisciplinary engagement in a quality improvement blood conservation protocol for craniosynostosis

OBJECTIVE

Patients undergoing open cranial vault remodeling for craniosynostosis frequently experience substantial blood loss requiring blood transfusion. Multiple reports in the literature have evaluated the impact of individual blood conservation techniques on blood transfusion rates during craniosynostosis surgery. The authors engaged a multidisciplinary team and assessed the impact of input from multiple stakeholders on the evolution of a comprehensive quality improvement protocol aimed at reducing or eliminating blood transfusion in patients undergoing open surgery for craniosynostosis.

METHODS

Over a 4-year period from 2012 to 2016, 39 nonsyndromic patients were operated on by a single craniofacial plastic surgeon. Initially, no clear blood conservation protocol existed, and specific interventions were individually driven. In 2014, a new pediatric neurosurgeon joined the craniofacial team, and additional stakeholders in anesthesiology, transfusion medicine, critical care, and hematology were brought together to evaluate opportunities for developing a comprehensive blood conservation protocol. The initial version of the protocol involved the standardized administration of intraoperative aminocaproic acid (ACA) and the use of a cell saver. In the second version of the protocol, the team implemented the preoperative use of erythropoietin (EPO). In addition, intraoperative and postoperative resuscitation and transfusion guidelines were more clearly defined. The primary outcomes of estimated blood loss (EBL), transfusion rate, and intraoperative transfusion volume were analyzed. The secondary impact of multidisciplinary stakeholder input was inferred by trends in the data obtained with the implementation of the partial and full protocols.

RESULTS

Implementing the full quality improvement protocol resulted in a 66% transfusion-free rate at the time of discharge compared to 0% without any conservation protocol and 27% with the intermediate protocol. The administration of EPO significantly increased starting hemoglobin/hematocrit (11.1 g/dl/31.8% to 14.7 g/dl/45.6%, p < 0.05). The group of patients receiving ACA had lower intraoperative EBL than those not receiving ACA, and trends in the final-protocol cohort, which had received both preoperative EPO and intraoperative ACA, demonstrated decreasing transfusion volumes, though the decrease did not reach statistical significance.

CONCLUSIONS

Patients undergoing open calvarial vault remodeling procedures benefit from the input of a multidisciplinary stakeholder group in blood conservation protocols. Further research into comprehensive protocols for blood conservation may benefit from input from the full surgical team (plastic surgery, neurosurgery, anesthesiology) as well as additional pediatric subspecialty stakeholders including transfusion medicine, critical care, and hematology.

Optimizing Perioperative Red Blood Cell Utilization and Wastage in Pediatric Craniofacial Surgery

Utilization, wastage, and adverse consequences of assigning one full red blood cell (RBC) unit were investigated for children undergoing craniosynostosis surgery. The authors hypothesized that significant RBC wastage in the perioperative period exists for pediatric craniofacial surgery. The authors sought to determine what factors could guide patient-specific blood product preparation by evaluating utilization and wastage of RBCs in pediatric patients undergoing surgical correction of craniosynostosis. Eighty-five children with craniosynostosis undergoing surgical correction at our institution between July 2013 and June 2015 were identified. Fifty-three patients received RBC transfusion in the perioperative period, while 32 patients were not transfused. Primary outcome measures were intraoperative, postoperative, and total percent of RBC wastage. Secondary analysis compared the impact of patient weight and procedure type on perioperative RBC wastage. Of the 53 patients who received perioperative RBC transfusion, 35 patients received a volume of blood less than the full volume of the RBC unit while 18 patients received the full volume of blood. There was no significant relationship between perioperative RBC wastage, the type of craniofacial procedure performed, or the duration of surgical time. Children who received a perioperative transfusion and had RBC wastage weighed significantly less than those who received a full volume. These findings suggest that for craniofacial surgical patients weighing less than 10 kg, a protocol that splits cross-matched RBC units can decrease perioperative RBC wastage and blood donor exposure. A future prospective study will determine the success of this intervention as well as the potential to decrease exposure to multiple blood donors.

Operative Time as the Predominant Risk Factor for Transfusion Requirements in Nonsyndromic Craniosynostosis Repair

Background:

Despite recent advances in surgical, anesthetic, and safety protocols in the management of nonsyndromic craniosynostosis (NSC), significant rates of intraoperative blood loss continue to be reported by multiple centers. The purpose of the current study was to examine our center’s experience with the surgical correction of NSC in an effort to determine independent risk factors of transfusion requirements.

Methods:

A retrospective cohort study of patients with NSC undergoing surgical correction at the Montreal Children’s Hospital was carried out. Baseline characteristics and perioperative complications were compared between patients receiving and not receiving transfusions and between those receiving a transfusion in excess or <25 cc/kg. Logistic regression analysis was carried out to determine independent predictors of transfusion requirements.

Results:

A total of 100 patients met our inclusion criteria with a mean transfusion requirement of 29.6 cc/kg. Eighty-seven patients (87%) required a transfusion, and 45 patients (45%) required a significant (>25 cc/kg) intraoperative transfusion. Regression analysis revealed that increasing length of surgery was the main determinant for intraoperative (P = 0.008; odds ratio, 18.48; 95% CI, 2.14–159.36) and significant (>25 cc/kg) intraoperative (P = 0.004; odds ratio, 1.95; 95% CI, 1.23–3.07) transfusions.

Conclusions:

Our findings suggest increasing operative time as the predominant risk factor for intraoperative transfusion requirements. We encourage craniofacial surgeons to consider techniques to streamline the delivery of their selected procedure, in an effort to reduce operative time while minimizing the need for transfusion.

Perioperative Outcomes and Management in Pediatric Complex Cranial Vault Reconstruction

Background

The Pediatric Craniofacial Collaborative Group established the Pediatric Craniofacial Surgery Perioperative Registry to elucidate practices and outcomes in children with craniosynostosis undergoing complex cranial vault reconstruction and inform quality improvement efforts. The aim of this study is to determine perioperative management, outcomes, and complications in children undergoing complex cranial vault reconstruction across North America and to delineate salient features of current practices.

Methods

Thirty-one institutions contributed data from June 2012 to September 2015. Data extracted included demographics, perioperative management, length of stay, laboratory results, and blood management techniques employed. Complications and outlier events were described. Outcomes analyzed included total blood donor exposures, intraoperative and perioperative transfusion volumes, and length of stay outcomes.

Results

One thousand two hundred twenty-three cases were analyzed: 935 children aged less than or equal to 24 months and 288 children aged more than 24 months. Ninety-five percent of children aged less than or equal to 24 months and 79% of children aged more than 24 months received at least one transfusion. There were no deaths. Notable complications included cardiac arrest, postoperative seizures, unplanned postoperative mechanical ventilation, large-volume transfusion, and unplanned second surgeries. Utilization of blood conservation techniques was highly variable.

Conclusions

The authors present a comprehensive description of perioperative management, outcomes, and complications from a large group of North American children undergoing complex cranial vault reconstruction. Transfusion remains the rule for the vast majority of patients. The occurrence of numerous significant complications together with large variability in perioperative management and outcomes suggest targets for improvement.

The role of tranexamic acid in prevention of hemorrhage in major spinal surgeries

Background:

Blood loss that necessitates blood transfusion is one of the most frequent complications of major spinal surgeries. This study has been designed to evaluate the efficacy and safety of prophylactic tranexamic acid (TA) in decreasing perioperative blood loss.

Materials and Methods:

From January to August 2011, all the patients who needed major spinal surgeries and aged between 18 and 60-year-old were divided into two groups randomly, the experimental group received 10 mg/kg of TA 20 min after inducing the anesthesia as loading dose followed by 0.5 mg/kg/h until skin closure and the control group received equal amounts of normal saline as placebo. Intraoperative blood loss was recorded by estimating blood with the suction tube plus the number of bloody gasses. The amounts compared between the 2 groups and analyzed.

Results:

Forty patients were enrolled in this study in the first group intraoperative, the 1^st and 2^nd postoperative days, the mean blood loss were 574 ml, 80.5 ml, and 669.5 ml while in the second group were 797 ml, 124 ml, and 921.5 ml.

Conclusion:

TA seems to be safe and can be considered in spinal surgeries with significant excepted blood loss especially in female patients and instrumental procedures. We suggest further studies on TAs efficacy and safety in larger scales.

Pediatric Patient Blood Management Programs: Not Just Transfusing Little Adults

Red blood cell transfusions are a common life-saving intervention for neonates and children with anemia, but transfusion decisions, indications, and doses in neonates and children are different from those of adults. Patient blood management (PBM) programs are designed to assist clinicians with appropriately transfusing patients. Although PBM programs are well recognized and appreciated in the adult setting, they are quite far from standard of care in the pediatric patient population. Adult PBM standards cannot be uniformly applied to children, and there currently is significant variation in transfusion practices. Because transfusing unnecessarily can expose children to increased risk without benefit, it is important to design PBM programs to standardize transfusion decisions. This article assesses the key elements necessary for a successful pediatric PBM program, systematically explores various possible pediatric specific blood conservation strategies and the current available literature supporting them, and outlines the gaps in the evidence suggesting need for further/improved research. Pediatric PBM programs are critically important initiatives that not only involve a cooperative effort between pediatric surgery, anesthesia, perfusion, critical care, and transfusion medicine services but also need operational support from administration, clinical leadership, finance, and the hospital information technology personnel. These programs also expand the scope for high-quality collaborative research. A key component of pediatric PBM programs is monitoring pediatric blood utilization and assessing adherence to transfusion guidelines. Data suggest that restrictive transfusion strategies should be used for neonates and children similar to adults, but further research is needed to assess the best oxygenation requirements, hemoglobin threshold, and transfusion strategy for patients with active bleeding, hemodynamic instability, unstable cardiac disease, and cyanotic cardiac disease. Perioperative blood management strategies include minimizing blood draws, restricting transfusions, intraoperative cell salvage, acute normovolemic hemodilution, antifibrinolytic agents, and using point-of-care tests to guide transfusion decisions. However, further research is needed for the use of intravenous iron, erythropoiesis-stimulating agents, and possible use of whole blood and pathogen inactivation. There are numerous areas where newly formed collaborations could be used to investigate pediatric transfusion, and these studies would provide critical data to support vital pediatric PBM programs to optimize neonatal and pediatric care.

Association of postoperative furosemide use with a reduced blood transfusion rate in sagittal craniosynostosis surgery

OBJECT A major challenge in sagittal craniosynostosis surgery is the high transfusion rate (50%-100%) related to blood loss in small pediatric patients. Several approaches have been proposed to prevent packed red blood cell (PRBC) transfusion, including endoscopic surgery, erythropoietin ortranexamic acid administration, and preoperative hemodilution. The authors hypothesized that a significant proportion of postoperative anemia observed in pediatric patients is actually dilutional. Consequently, since 2005, at CHU Sainte-Justine, furosemide has been administered to correct the volemic status and prevent PRBC transfusion. The purpose of this study was to evaluate the impact of postoperative furosemide administration on PRBC transfusion rates. METHODS This was a retrospective study of 96 consecutive patients with sagittal synostosis who underwent surgery at CHU Sainte-Justine between January 2000 and May 2012. The mean age at surgery was 4.9 ± 1.5 months (range 2.8-8.7 months). Patients who had surgery before 2005 constituted the control group. Those who had surgery in 2005 or 2006 were considered part of an implementation phase because furosemide administration was not routine. Patients who had surgery after 2006 were part of the experimental (or furosemide) group. Transfusion rates among the 3 groups were compared. The impact of furosemide administration on transfusion requirement was also measured while accounting for other variables of interest in a multiple logistic regression model. RESULTS The total transfusion rate was significantly reduced in the furosemide group compared with the control group (31.3% vs 62.5%, respectively; p = 0.009), mirroring the decrease in the postoperative transfusion rate between the groups (18.3% vs 50.0%, respectively; p = 0.003). The postoperative transfusion threshold remained similar throughout the study (mean hemoglobin 56.0 g/dl vs 60.9 g/dl for control and furosemide groups, respectively; p = 0.085). The proportion of nontransfused patients with recorded hemoglobin below 70 g/dl did not differ between the control and furosemide groups (41.7% vs 28.6%, respectively; p = 0.489). Surgical procedure, preoperative hemoglobin level, estimated blood loss, and furosemide administration significantly affected the risk of receiving a postoperative PRBC transfusion. When these variables were analyzed in a multiple logistic regression model, furosemide administration remained strongly associated with a reduced risk of being exposed to a blood transfusion (OR 0.196, p = 0.005). There were no complications related to furosemide administration. CONCLUSIONS A significant part of the postoperative anemia observed in patients who underwent sagittal craniosynostosis surgery was due to hypervolemic hemodilution. Correction of the volemic status with furosemide administration significantly reduces postoperative PRBC transfusion requirements in these patients.

Minimizing blood transfusions in the surgical correction of craniosynostosis: a 10-year single-center experience

INTRODUCTION

Our center previously reported low transfusion rates for craniosynostosis surgery by two experienced neurosurgeons using standard intraoperative techniques and acceptance of low hemoglobin levels. This study evaluated whether low rates were maintained over the last 10 years and if a less experienced neurosurgeon, trained in and practicing in the same environment, could achieve similar outcomes.

METHODS

All craniosynostosis operations performed in children between 2004 and 2015 were reviewed retrospectively. Transfusion rates were calculated. Analyses examined the relationship of transfusion to craniosynostosis type, surgical procedure, redo operation, surgeon, and perioperative hemoglobin levels.

RESULTS

Two hundred eighteen patients were included: 71 open sagittal, 28 endoscopic-assisted sagittal, 32 unicoronal, 14 bicoronal, 42 metopic, and 31 multisuture. Median age at operation was 9.1 months. Overall transfusion rate was 24 %: 17 % open sagittal, 7 % endoscopic-assisted sagittal, 6 % unicoronal, 21 % bicoronal, 45 % metopic, and 45 % multisuture. The timing of transfusions were 75, 21, and 4 % for intraoperative, postoperative, and both, respectively. Patients not receiving transfusion had a mean lowest hemoglobin of 87 g/l (range 61-111) intraoperatively and 83 g/l (range 58-115) postoperatively. Mean lowest hemoglobin values were significantly lower in those necessitating intraoperative (75 g/l, range 54-102) or postoperative (59 g/l, range 51-71) transfusions. There was no significant difference in transfusion rate between less and more experienced surgeons. There were no cardiovascular complications or mortalities.

CONCLUSION

In craniosynostosis surgery, reproducible, long-term low blood transfusion rates were able to be maintained at a single center by careful intraoperative technique and acceptance of low intraoperative and postoperative hemoglobin levels in hemodynamically stable patients. Furthermore, low rates were also achieved by an inexperienced neurosurgeon in the group. This suggests that these results may be achievable by other neurosurgeons, who follow a similar protocol.

Use of tranexamic acid in craniosynostosis surgery

Background

Intraoperative tranexamic acid (TXA) administration has been used to abate blood loss in a variety of surgical procedures. Several recent studies have supported its efficacy in reducing transfusion requirements in pediatric cranial vault reconstruction (CVR).

Objective

To conduct a retrospective chart review to determine whether a significant reduction in packed red blood cell (PRBC) and fresh frozen plasma (FFP) transfusions exists when TXA is used.

Methods

A retrospective cohort study of 28 patients who underwent CVR for sagittal craniosynostosis was performed. Transfusion requirements for 14 patients who did not receive TXA were compared with 14 patients who did. Predictors of increased blood product transfusion were also studied.

Results

Total volume of PRBC transfusion was reduced by 50% with the use of TXA (P=0.004) with a 34% reduction in intraoperative PRBC transfusion (P=0.017) and a 67% reduction in postoperative PRBC transfusion (P<0.001). Total volume of FFP transfusion was reduced by 46% (P=0.002) and postoperative FFP transfusion was reduced by 100% (P=0.001). The use of TXA was associated with a lower total volume of PRBC (P=0.003) and FFP (P=0.003) transfusions. Older patient age was associated with lower total volume of PRBC transfused (P=0.046 and P=0.002), but not with FFP (P=0.183 and P=0.099) transfusion volumes. Increasing patient weight was associated with lower PRBC (P=0.010 and P=0.020) and FFP (P=0.045 and P=0.016) transfusion volumes.

Conclusion

TXA decreased blood product transfusion requirements in patients undergoing CVR for sagittal craniosynostosis, and should be a routine part of the strategy to reduce blood loss in these procedures.

Prophylactic versus reactive transfusion of thawed plasma in patients undergoing surgical repair of craniosynostosis: a randomized clinical trial

BACKGROUND

Surgical repair of craniosynostosis in young children is associated with copious bleeding and often coagulopathy. Typically, a reactive transfusion strategy is used to treat coagulopathy whereby fresh frozen plasma (FFP) is given only after clinical manifestation of clotting abnormality. This prospective, randomized clinical trial was designed to test the hypothesis that prophylactic FFP during craniofacial surgery reduces blood loss and blood transfusion requirements compared to a reactive FFP transfusion strategy.

METHODS

Eighty-one patients less than 2 years of age requiring primary repair of craniosynostosis were randomized to receive FFP using either a prophylactic or reactive strategy. Laboratory values were measured at four standardized time points. The volume of blood products transfused, length of stay in the pediatric intensive care unit (PICU), hospital length of stay, and number of donor exposures were recorded for each patient.

RESULTS

The prophylactic FFP group received a significantly greater average volume of FFP compared to the reactive group (29.7 ml·kg(-1) vs 16.1 ml·kg(-1) ; P < 0.001), which was associated with improvement in coagulation values at multiple time points. However, there was no difference in blood transfusion requirements or blood loss between the two groups. The two transfusion strategies resulted in similar median donor exposures. There was no difference in PICU or hospital length of stay.

CONCLUSION

A reactive FFP transfusion strategy required less plasma transfusion and was associated with similar rates of blood loss and PRBC transfusion as prophylactic FFP despite improvement in coagulation values in the prophylactic FFP group.

Effect of low dose tranexamic acid on intra-operative blood loss in neurosurgical patients

Background:

Blood loss is often a major complication in neurosurgery that requires transfusion of multiple units of blood. The purpose of this study was to assess the effect of tranexamic acid (TXA) on intraoperative blood loss and the need for blood transfusion in patients undergoing craniotomy for tumor excision.

Materials and Methods:

A total of 100 patients aged 18-60 years, with American Society of Anesthesiologists physical Status 1 and 2 scheduled to undergo elective craniotomy for tumor excision were enrolled. Patients received 10 mg/kg bolus about 20 min before skin incision followed by 1 mg/kg/h infusion of either TXA or saline. Hemodynamic variables, intravenous fluid transfused, amount of blood loss and blood given were measured every 2 h. Laboratory parameters such as serum electrolytes and fibrinogen values were measured every 3 h. On the 5^th postoperative day hemoglobin (POD Hb5), Hb estimation was done and the estimated blood loss (EBL) calculated. Patients were also monitored for any complications.

Results:

The Mean heart rate in TXA group was significantly lower compared with the saline group. Mean arterial pressure and fibrinogen levels were higher in TXA group. The mean total blood loss in the TXA group was less than in the saline group. Blood transfusion requirements were comparable in two groups. The EBL and POD5 Hb were comparable in two groups.

Conclusion:

Even though, there is a significant reduction in the total amount of blood loss in TXA group. However, there was no reduction in intraoperative transfusion requirement.

Use of tranexamic acid in craniosynostosis surgery

BACKGROUND

Intraoperative tranexamic acid (TXA) administration has been used to abate blood loss in a variety of surgical procedures. Several recent studies have supported its efficacy in reducing transfusion requirements in pediatric cranial vault reconstruction (CVR).

OBJECTIVE

To conduct a retrospective chart review to determine whether a significant reduction in packed red blood cell (PRBC) and fresh frozen plasma (FFP) transfusions exists when TXA is used.

METHODS

A retrospective cohort study of 28 patients who underwent CVR for sagittal craniosynostosis was performed. Transfusion requirements for 14 patients who did not receive TXA were compared with 14 patients who did. Predictors of increased blood product transfusion were also studied.

RESULTS

Total volume of PRBC transfusion was reduced by 50% with the use of TXA (P=0.004) with a 34% reduction in intraoperative PRBC transfusion (P=0.017) and a 67% reduction in postoperative PRBC transfusion (P<0.001). Total volume of FFP transfusion was reduced by 46% (P=0.002) and postoperative FFP transfusion was reduced by 100% (P=0.001). The use of TXA was associated with a lower total volume of PRBC (P=0.003) and FFP (P=0.003) transfusions. Older patient age was associated with lower total volume of PRBC transfused (P=0.046 and P=0.002), but not with FFP (P=0.183 and P=0.099) transfusion volumes. Increasing patient weight was associated with lower PRBC (P=0.010 and P=0.020) and FFP (P=0.045 and P=0.016) transfusion volumes.

CONCLUSION

TXA decreased blood product transfusion requirements in patients undergoing CVR for sagittal craniosynostosis, and should be a routine part of the strategy to reduce blood loss in these procedures.

Minimizing transfusion requirements for children undergoing craniosynostosis repair: the CHoR protocol

OBJECT

Children with craniosynostosis may require cranial vault remodeling to prevent or relieve elevated intracranial pressure and to correct the underlying craniofacial abnormalities. The procedure is typically associated with significant blood loss and high transfusion rates. The risks associated with transfusions are well documented and include transmission of infectious agents, bacterial contamination, acute hemolytic reactions, transfusion-related lung injury, and transfusion-related immune modulation. This study presents the Children's Hospital of Richmond (CHoR) protocol, which was developed to reduce the rate of blood transfusion in infants undergoing primary craniosynostosis repair.

METHODS

A retrospective chart review of pediatric patients treated between January 2003 and Febuary 2012 was performed. The CHoR protocol was instituted in November 2008, with the following 3 components; 1) the use of preoperative erythropoietin and iron therapy, 2) the use of an intraoperative blood recycling device, and 3) acceptance of a lower level of hemoglobin as a trigger for transfusion (< 7 g/dl). Patients who underwent surgery prior to the protocol implementation served as controls.

RESULTS

A total of 60 children were included in the study, 32 of whom were treated with the CHoR protocol. The control (C) and protocol (P) groups were comparable with respect to patient age (7 vs 8.4 months, p = 0.145). Recombinant erythropoietin effectively raised the mean preoperative hemoglobin level in the P group (12 vs 9.7 g/dl, p < 0.001). Although adoption of more aggressive surgical vault remodeling in 2008 resulted in a higher estimated blood loss (212 vs 114.5 ml, p = 0.004) and length of surgery (4 vs 2.8 hours, p < 0.001), transfusion was performed in significantly fewer cases in the P group (56% vs 96%, p < 0.001). The mean length of stay in the hospital was shorter for the P group (2.6 vs 3.4 days, p < 0.001).

CONCLUSIONS

A protocol that includes preoperative administration of recombinant erythropoietin, intraoperative autologous blood recycling, and accepting a lower transfusion trigger significantly decreased transfusion utilization (p < 0.001). A decreased length of stay (p < 0.001) was seen, although the authors did not investigate whether composite transfusion complication reductions led to better outcomes.

Evidence-based medicine: Craniosynostosis

LEARNING OBJECTIVES

After studying this article, the participant should be able to: (1) Make the appropriate diagnosis for each of the single-sutural synostoses, based on the physical examination. (2) Explain the functional concerns associated with these synostoses and why surgical correction is indicated. (3) Distinguish between the different types of surgical corrections available, the timing for these various interventions, and in what ways these treatments achieve overall management objectives. (4) Identify the basic goals involved in caring for the syndromic synostoses.

SUMMARY

This article provides an overview of the diagnosis and management of infants with craniosynostosis. This review also incorporates some of the treatment philosophies followed at The Craniofacial Center in Dallas, but is not intended to be an exhaustive treatise on the subject. It is designed to serve as a reference point for further in-depth study by review of the reference articles presented. This information base is then used for self-assessment and benchmarking in parts of the Maintenance of Certification process of the American Board of Plastic Surgery.

Anesthesia for craniofacial surgery in infancy

Anesthetic management of infants undergoing craniofacial surgery can be challenging. Primary concerns for the anesthesiologist include blood loss and its management. The evolution of procedures to treat craniosynostosis has resulted in improvements in perioperative morbidity, including decreased blood loss and transfusion, shorter operations, and shorter hospital stays. An understanding of the procedures performed to treat craniosynostosis is necessary to provide optimal anesthetic management. Descriptions of current surgical techniques and approaches to anesthetic care are presented in this review.

Population pharmacokinetics of epsilon-aminocaproic acid in infants undergoing craniofacial reconstruction surgery

BACKGROUND

Understanding the clinical pharmacology of the antifibrinolytic epsilon-aminocaproic acid (EACA) is necessary for rational drug administration in children. The aim of this study is to determine the pharmacokinetics (PKs) of EACA in infants aged 6-24 months undergoing craniofacial reconstruction surgery.

METHODS

Cohorts of six infants were enrolled sequentially to one of the three escalating loading dose-continuous i.v. infusion (CIVI) regimens: 25 mg kg(-1), 10 mg kg(-1) h(-1); 50 mg kg(-1), 20 mg kg(-1) h(-1); 100 mg kg(-1), 40 mg kg(-1) h(-1). Plasma EACA concentrations were determined using a validated high-performance liquid chromatography-tandem mass spectrometry assay. A population non-linear mixed effects modelling approach was used to characterize EACA PKs.

RESULTS

Population PK parameters of EACA were estimated using a two-compartment disposition model with weight expressed as an allometric covariate and an age effect. The typical patient in this study had an age of 38.71 weeks and a weight of 8.82 kg. PK parameters for this typical patient were: pre-/postoperative plasma drug clearance of 32 ml min(-1) (3.6 ml kg(-1) min(-1)), inter-compartmental clearance of 42.4 ml min(-1) (4.8 ml min(-1) kg(-1)), central volume of distribution of 1.27 litre (0.14 litre kg(-1)), and peripheral volume of distribution of 2.53 litre (0.29 litre kg(-1)). Intra-operative clearance and central volume of distribution were 89% and 80% of the pre-/postoperative value, respectively.

CONCLUSIONS

EACA clearance increased with weight and age. The dependence of clearance on body weight supports weight-based dosing. Based on this study, a loading dose of 100 mg kg(-1) followed by a CIVI of 40 mg kg(-1) h(-1) is appropriate to maintain target plasma EACA concentrations in children aged 6-24 months undergoing these procedures.

Anesthesia for surgery related to craniosynostosis: a review. Part 2

The management of children with craniosynostosis is multidisciplinary and has evolved significantly over the past five decades. The treatment is primarily surgical. The anesthetic challenges continue to be the management of massive blood transfusion and prolonged anesthesia in small children, often further complicated by syndrome-specific issues. This two-part review aims to provide an overview of the anesthetic considerations for these children. The first part described the syndromes associated with craniosynostosis, the provision of services in the UK, surgical techniques, preoperative issues and induction and maintenance of anesthesia. This second part will explore hemorrhage control, the use of blood products, metabolic disturbance and postoperative issues.

Effect of transfusion guidelines on postoperative transfusion in children undergoing craniofacial reconstruction surgery

OBJECTIVE

To assess the effect of implementation of population-specific postoperative management guidelines on postoperative transfusion in children undergoing cranial vault reconstruction surgery.

DESIGN

Retrospective observational study with historical controls.

SETTING

Single, large, academic tertiary pediatric hospital.

PATIENTS

: Children aged 6 months to 17 yrs undergoing fronto-orbital advancement or posterior cranial vault reconstruction surgery enrolled in our craniofacial surgery perioperative registry from April 14, 2008 to September 7, 2011.

INTERVENTION

Postoperative management guidelines for children undergoing cranial vault reconstruction surgery were implemented on December 1, 2009. These management guidelines included projected surgical drain output as well as specific transfusion thresholds for packed red blood cells and hemostatic blood products.

MEASUREMENTS AND MAIN RESULTS

We queried our craniofacial surgery perioperative registry for children who underwent cranial vault reconstruction to assess transfusion practices before and after the implementation of the postoperative guidelines. Subjects were divided into a preguideline cohort and a postguideline cohort. Perioperative demographic data and postoperative transfusion data were compared between the two groups. The registry query returned data on 59 procedures in the preguideline cohort and 58 procedures in the postguideline cohort. The immediate postoperative hematocrit and the postoperative blood loss through surgical drains were not statistically different in the two groups. The prevalence of postoperative transfusion of any blood product was significantly less in the postguideline cohort (17% vs. 42%, p = .003). Most of the transfusion reduction was achieved through a reduction in fresh frozen plasma transfusion (5% vs. 25%, p = .002).

CONCLUSIONS

In this observational study, the implementation of postoperative management guidelines was associated with a 60% reduction in postoperative transfusion. The use of transfusion thresholds is a simple, inexpensive, and effective strategy for transfusion reduction and should be a first-line approach to perioperative transfusion reduction in this population.

Factors influencing blood loss and allogeneic blood transfusion practice in craniosynostosis surgery

OBJECTIVE/AIMS

To identify factors influencing perioperative blood loss and transfusion practice in craniosynostotic corrections.

BACKGROUND

Craniosynostotic corrections are associated with large amounts of blood loss and high transfusion rates.

METHODS

A retrospective analysis was performed of all pediatric craniosynostotic corrections during the period from January 2003 to October 2009. The primary endpoint was the receipt of an allogeneic blood transfusion (ABT) during or after surgery. Pre-, intra-, and postoperative data were acquired using the electronic hospital registration systems and patients' charts.

RESULTS

Forty-four patients were operated using open surgical techniques. The mean estimated blood loss during surgery was 55 ml·kg(-1). In 42 patients, red blood cells were administered during or after surgery with a mean of 38 ml·kg(-1). In 23 patients, fresh frozen plasma was administered with a mean of 28 ml·kg(-1). A median of two different donors per recipient was found. Longer duration of surgery and lower bodyweight were associated with significantly more blood loss and red blood cell transfusions. Higher perioperative blood loss and surgery at an early age were correlated with a longer duration of admission.

CONCLUSIONS

In this study, craniosynostotic corrections were associated with large amounts of blood loss and high ABT rates. The amount of ABT could possibly be reduced by appointing a dedicated team of physicians, by using new less-invasive surgical techniques, and by adjusting anesthetic techniques.

Perioperative management of children undergoing craniofacial reconstruction surgery: a practice survey

OBJECTIVE/AIMS

  To assess current practices in the management of children undergoing craniofacial surgery and identify areas of significant practice variability with the intent to direct future research.

BACKGROUND

  The perioperative management of infants and children undergoing craniofacial reconstruction surgery can be challenging because of the routine occurrence of significant blood loss with associated morbidity. A variety of techniques have been described to improve the care for these children. It is presently unknown to what extent these practices are currently employed.

METHODS

  A web-based survey was sent to representatives from 102 institutions. One individual per institution was surveyed to prevent larger institutions from being over-represented in the results.

RESULTS

  Requests to complete the survey were sent to 102 institutions; 48 surveys were completed. The survey was composed of two parts: management of infants undergoing strip craniectomies, and management of children undergoing major craniofacial reconstruction.

CONCLUSIONS

  Significant variability exists in the management of children undergoing these procedures; further study is required to determine the optimal management strategies. Clinical trials assessing the utility of central venous pressure and other hemodynamic monitoring modalities would enable evidence-based decision-making for monitoring in these children. The development of institutional transfusion thresholds should be encouraged, as there exists a body of evidence supporting their efficacy and safety.

An evidence-based approach to craniosynostosis

The Maintenance of Certification module series is designed to help the clinician structure his or her study in specific areas appropriate to his or her clinical practice. This article is prepared to accompany practice-based assessment of preoperative assessment, anesthesia, surgical treatment plan, perioperative management, and outcomes. In this format, the clinician is invited to compare his or her methods of patient assessment and treatment, outcomes, and complications, with authoritative, information-based references. This information base is then used for self-assessment and benchmarking in parts II and IV of the Maintenance of Certification process of the American Board of Plastic Surgery. This article is not intended to be an exhaustive treatise on the subject. Rather, it is designed to serve as a reference point for further in-depth study by review of the reference articles presented.

Blood transfusion risks and alternative strategies in pediatric patients

Although the safety of the blood supply has been greatly improved, there still remain both infectious and noninfectious risks to the patient. The incidence of noninfectious transfusion reactions is greater than that of infectious complications. Furthermore, the mortality associated with noninfectious risks is significantly higher. In fact, noninfectious risks account for 87-100% of fatal complications of transfusions. It is concerning to note that the majority of pediatric reports relate to human error such as overtransfusion and lack of knowledge of special requirements in the neonatal age group. The second most frequent category is acute transfusion reactions, majority of which are allergic in nature. It is estimated that the incidence of adverse outcome is 18:100,000 red blood cells issued for children aged less than 18 years and 37:100,000 for infants. The comparable adult incidence is 13:100,000. In order to decrease the risks associated with transfusion of blood products, various blood-conservation strategies can be utilized. Modalities such as acute normovolemic hemodilution, hypervolemic hemodilution, deliberate hypotension, antifibrinolytics, intraoperative blood salvage, and autologous blood donation are discussed and the pediatric literature is reviewed. A discussion of transfusion triggers, and algorithms as well as current research into alternatives to blood transfusions concludes this review.

Perioperative management of a child with von Willebrand disease undergoing surgical repair of craniosynostosis: looking at unusual targets

We report the successful management of a craniosynostosis repair in a child with severe Type I von Willebrand disease diagnosed during the preoperative assessment and treated by coagulation factor VIII and ristocetin cofactor. Collaboration among the anesthesiologist, the neurosurgeon, the clinical pathologist, and the pediatric hematologist is important for successful management.

Blood conservation strategies in pediatric anesthesia

Management of bleeding in the neonate, infant, or child presents its own set of dilemmas and challenges. One of the primary problems is the lack of good scientific evidence regarding the best management strategies for children rather than for adults. The key to success in the predicament is firstly to ensure that the physician has a clear understanding of the underlying normal physiology of the young child's hematologic status. Then by adding knowledge of the abnormal pathology that is being presented, the physician can at least understand what anomalies he or she is facing. Once all the available information concerning the patient's clinical condition and the options available has been well digested, a multidisciplinary approach allows the optimal use of all available resources. Good teamwork, understanding, and communication between all vested parties allows for a synergistic relationship to enhance patient care and give the best available end result.

Perioperative management of pediatric patients with craniosynostosis

Craniosynostosis, premature closures of the skull sutures, results in dysmorphic features if left untreated. Brain growth and cognitive development may also be impacted. Craniosynostosis repair is usually performed in young infants and has its perioperative challenges. This article provides background information about the different forms of craniosynostosis, with an overview of associated anomalies, genetic influences, and their connection with cognitive function. It also discusses the anesthetic considerations for perioperative management, including blood-loss management and strategies to reduce homologous blood transfusions.

Minimizing perioperative blood loss and transfusions in children

PURPOSE

To summarize the physiology and pathophysiology relevant to perioperative blood loss in children. Strategies to reduce blood losses are reviewed.

METHODS

The literature was reviewed using the electronic library PUBMED and the Cochrane Database of Systematic Reviews. Relevant studies published in English or French with an English abstract are included. The following keywords were used: children, blood transfusion, surgical blood loss, erythropoietin, autologous blood, red blood cell saver, normovolemic hemodilution, desmopressin, aminocaproic acid, tranexamic acid, aprotinin, cardiac surgery, liver transplantation and scoliosis surgery.

MAIN FINDINGS

For patients with idiopathic scoliosis, predonation with or without the addition of erythropoietin is a safe and effective way to avoid the use of allogenic blood products. For open heart procedures: whole blood of less than 48 hr is helpful for children of less than two years of age undergoing complex procedures; tranexamic acid may be helpful for cyanotic heart disease and, to a lesser degree, for reoperations; while anti-kallikrein blood levels of aprotinin may both reduce the need for allogenic blood transfusions and improve postoperative oxygenation in infants.

CONCLUSION

Reducing perioperative allogenic blood transfusions is possible in pediatric patients provided that prophylactic measures are adapted to age, disease and type of surgery.

Blood Conservation in Pediatric Anesthesia

This review focuses on perioperative blood conservation techniques and the role of transfusion triggers and algorithms, preoperative autologous donation, acute normovolemic hemodilution, intraoperative blood salvage, deliberate hypotension, and preoperative recombinant human erythropoietin in avoiding allogeneic blood transfusion in pediatric patients.

Blood sparing in craniosynostosis surgery

One of the main risks of craniosynostosis surgery is the possible need for an allogenic blood transfusion (ABT). Most patients are operated on in the first months of life, when physiological conditions are particularly sensitive to even limited blood losses. Furthermore, most surgical techniques proposed in the past were based on extensive craniectomies and cranial remodeling. Because of the known infective and immunologic risks of ABT, in recent years more attention has been dedicated to factors that might help reduce the risk of ABT. We review recent preoperative (ie, erythropoietin administration), intraoperative (ie, acute normovolemic hemodilution, intraoperative blood salvage), and postoperative (ie, clinical monitoring, postoperative blood salvage) anesthesiologic procedures developed with this aim in mind. We also consider operative techniques and technical apparatus that reduce surgical invasiveness, particularly preoperative planning, age selection, and the role of endoscopic assistance and gradual distraction devices.

Preoperative acute normovolemic hemodilution: a meta-analysis

BACKGROUND

Acute normovolemic hemodilution (ANH) involves withdrawal of whole blood with concurrent infusion of fluids to maintain normovolemia. The aim of this study was to quantify the efficacy and safety of preoperative ANH with a systematic review and meta-analysis.

STUDY DESIGN AND METHODS

Randomized controlled trials were identified through MEDLINE (1966-2002) and the Cochrane Controlled Trials Database and with hand searching of journals. All trials of preoperative ANH reporting on allogeneic transfusion, bleeding, or adverse outcomes were included. Paired reviewers independently abstracted data. Outcomes were pooled using random-effects models.

RESULTS

A total of 42 trials compared hemodilution to usual care or to another blood conservation method. The risk of allogeneic transfusion was similar among patients receiving ANH and those receiving usual care (relative risk [RR], 0.96; 95% CI, 0.90-1.01), or another blood conservation method (RR, 1.11; 95% CI, 0.96-1.28). Hemodiluted patients, however, were transfused from 1 to 2 fewer units of allogeneic blood. They had less total bleeding than patients receiving usual care (91 mL; 95% CI, 25-158 mL), although more intraoperative bleeding. Only one-third of studies reported on adverse events.

CONCLUSIONS

The literature supports only modest benefits from preoperative ANH. The safety of the procedure is unproven. Widespread adoption of ANH cannot be encouraged.

Anaesthetic management in facial bipartition surgery: The experience of one centre

Facial bipartition is amongst the most radical craniofacial surgery undertaken but is performed rarely. There is little published information on its anaesthetic management. We undertook a retrospective case-note review of 22 consecutive patients undergoing bipartition surgery by the same surgical team in one centre in the period 1993-2001. There were incomplete data for two cases and these were therefore excluded. Patients were aged 2 months to 19 years. Conditions treated were facial cleft (n = 5), frontonasal dysplasia (n = 7) and facial dysostosis (n = 8).Intra-operative complications included major haemorrhage (n = 4), bradycardia (n = 3) and unintentional tracheal extubation (n = 1). There were no peri-operative deaths. All patients required intra-operative blood transfusion and 15% of them had a postoperative haemoglobin concentration > 115% of their pre-operative value. In this series, four patients required postoperative lung ventilation for a median duration of 3 days. Infants < 14 months old were significantly more likely to receive a massive blood transfusion (p = 0.0002), to have an excessively high postoperative haematocrit (p = 0.008) and to require postoperative lung ventilation (p = 0.0002) compared with older patients. We conclude that patients in this age group have a significantly increased risk of postoperative complications.

Erythropoietin therapy and acute preoperative normovolaemic haemodilution in infants undergoing craniosynostosis surgery

BACKGROUND

A retrospective study was performed to evaluate whether pretreatment with erythropoietin and iron combined with acute preoperative normovolaemic haemodilution (APNH) could decrease homologous blood transfusion in craniosynostosis (CS) surgery. A treated group was compared with a historical group of infants who underwent surgery with no pretreatment.

METHODS

The charts of 25 healthy infants who underwent CS surgery were reviewed. Nine of them underwent surgery with no treatment beforehand. Sixteen infants were given erythropoietin at a dosage of 300 U.kg -1 two times per week and iron (elemental iron 10 mg.kg-1.day-1) for 3 weeks before surgery. On the day of surgery APNH was performed after induction of general anaesthesia; a precalculated amount of autologous blood was withdrawn and replaced by hydroxyethyl starch 6%.

RESULTS

Eleven of the 16 infants of the study group received only autologous blood. Five of 16 received homologous blood transfusion vs seven of nine infants in the control group.

CONCLUSIONS

APNH combined with erythropoietin was effective in reducing homologous blood requirements during CS surgery. Further studies are necessary on a larger scale to assess the role of this technique in avoiding homologous blood transfusion and to evaluate how infants can benefit from this combined approach.

[Perioperative management of blood loss during surgical treatment for craniosynostosis]

Blood saving is the major challenge during the surgical repair of craniofacial deformities. Treated patients have a low reserve volume and the techniques available to lower homologous blood transfusions are limited or insufficiently evaluated in this particular case. The most important factor determining blood loss is the quality of the surgical haemostasis. Blood saving begins with early preoperative evaluation of the patient's bleeding risk, which is a function of the type of surgery, of the surgical technique, of the number of sutures involved, of the length of surgery, and of the patients age, weight and physical status. Elaborated blood saving techniques such as preoperative autologous blood donation, erythropoietin administration, normovolaemic haemodilution, and peroperative autologous blood saving and reinfusion have revealed disappointing where used alone. These techniques require a heavy setup and still need to be evaluated extensively. They should be used in selected cases such as in patients with a very high risk of bleeding or face to Jehovah Witnesses. Monitoring during surgery should include precise evaluation of blood losses and haematocrit measurements at regular intervals. The haematocrit threshold allowing homologous blood transfusion should be set at 21%, provided that any other source of autologous blood is exhausted. Postoperative monitoring should also include precise evaluation of blood losses and haematocrit measurements. The 21% threshold should remain the reference during that period.