Dilutional coagulopathy in pediatric scoliosis surgery: A single center report

Thrombocytopenia in Critically Ill Children: A Review for Practicing Clinicians

Thrombocytopenia frequently occurs in patients before, during, and after admission to Pediatric Intensive Care Units (PICUs). In critically ill children, it is often due to multifactorial causes and can be a sign of significant organ dysfunction. This review summarizes the potential causes/mechanisms of thrombocytopenia in acutely ill children, their identification, and treatments, with special attention paid to septic patients. The mechanisms of thrombocytopenia include decreased production and sequestration, but the most common reason is increased destruction or consumption. This review specifically reviews and compares the presentation, pathogenesis, and treatment of disseminated intravascular coagulation (DIC) and the thrombotic microangiopathic spectrum (TMA), including thrombocytopenia-associated multiorgan failure (TAMOF), hemolytic uremic syndrome, and other diagnoses. The other etiologies discussed include HLH/MAS, immune thrombocytopenia, and dilutional thrombocytopenia. Finally, this review analyzes platelet transfusions, the various thresholds, and complications.

Postoperative coagulopathy among otherwise healthy pediatric patients undergoing open craniosynostosis repair: a retrospective study

Significant blood loss and resultant transfusion may lead to coagulopathy. The need for routine transfusion of non-RBC blood products in healthy pediatric patients suffering significant, yet controlled, intra-operative blood loss is controversial. Open craniosynostosis surgery is often associated with significant intra-operative blood loss and transfusion, and routinely preformed on otherwise healthy pediatric patients. Therefore, we found it as a useful model for our study, which aimed to assess the need for routine transfusion of non-RBC blood products in healthy pediatric patients suffering significant intra-operative blood loss. We conducted a retrospective cohort study of otherwise healthy pediatric patients, undergoing open craniosynostosis surgery and transfused solely with packed red blood cells (pRBCs) in a single large-volume tertiary surgical center, between January 2010 and December 2021. Among 457 eligible patients, 34 (7.4%) developed significant postoperative coagulopathy. Median [IQR] intra-operative pRBC transfusion volume was 17.4 ml kg^-1 [13.3, 23.1]. Patients who developed coagulopathy did not have higher postoperative pRBC transfusion rate (8.8% vs 3.8%, P = 0.16) or volume (median [IQR], 0 [0, 0] vs 0 [0, 0] ml, P = 0.15), nor higher hospital LOS (5 [4, 5] vs 5 [4, 5] days, P = 0.66). ICU LOS was 0.8 [0.7, 1] vs 0.7 [0.6, 0.8] days (P = 0.02), a difference of no clinical significance.  Conclusions: The incidence of significant coagulopathy after craniosynostosis surgery was low, and not associated with clinically important complications. In otherwise healthy pediatric patients, even significant intra-operative blood loss can be safely managed solely with intravenous fluids and pRBC transfusion. What is Known: • Significant intra-operative blood loss and resultant transfusion may lead to postoperative coagulopathy. • There are potential deleterious effects from both coagulopathy and administration of blood products. What is New: • Open craniosynostosis corrective surgery is a useful model for studying coagulopathy after significant intra-operative blood loss and transfusion in otherwise healthy children. • Under certain conditions, in otherwise healthy pediatric patients, even significant intra-operative blood loss can be safely treated with intravenous fluids and pRBC transfusion alone, with no clinically significant postoperative coagulopathy or its complications.

Variable Response to Antifibrinolytics Correlates with Blood-loss and Transfusion in Posterior Spinal Fusion

PURPOSE

Posterior spinal fusion (PSF) activates the fibrinolytic protease plasmin, which is implicated in blood loss and transfusion. While antifibrinolytic drugs have improved blood loss and reduced transfusion, variable blood loss has been observed in similar PSF procedures treated with the same dose of antifibrinolytics. However, both the cause of this and the appropriate measures to determine antifibrinolytic efficacy during high-blood-loss spine surgery are unknown, making clinical trials to optimize antifibrinolytic dosing in PSF difficult. We hypothesized that patients undergoing PSF respond differently to antifibrinolytic dosing, resulting in variable blood loss, and that specific diagnostic markers of plasmin activity will accurately measure the efficacy of antifibrinolytics in PSF.

METHODS

A prospective study of 17 patients undergoing elective PSF with the same dosing regimen of TXA was conducted. Surgery-induced plasmin activity was exhaustively analyzed in perioperative blood samples and correlated to measures of inflammation, bleeding, and transfusion.

RESULTS

While markers of in vivo plasmin activation (PAP and D-dimer) suggested significant breakthrough plasmin activation and fibrinolysis (P < 0.01), in vitro plasmin assays, including TEG, did not detect plasmin activation. In vivo measures of breakthrough plasmin activation correlated with blood loss (R2 = 0.400, 0.264; P < 0.01), transfusions (R2 = 0.388; P < 0.01), and complement activation (R2 = 0.346, P < 0.05).

CONCLUSIONS

Despite all patients receiving a high dose of TXA, its efficacy among patients was variable, indicated by notable intra-operative plasmin activity. Markers of in vivo plasmin activation best correlated with clinical outcomes. These findings suggest that the efficacy of antifibrinolytic therapy to inhibit plasmin in PSF surgery should be determined by markers of in vivo plasmin activation in future studies.

LEVEL OF EVIDENCE

Level II-diagnostic.

Blood Loss and Transfusion in a Pediatric Scoliosis Surgery Cohort in the Antifibrinolytic Era

Children and adolescents undergoing posterior spinal fusion for scoliosis experience high rates of bleeding and blood product transfusion. Antifibrinolytic therapy is one key strategy to decrease blood loss and transfusion in pediatric scoliosis surgery. Here we review 172 pediatric scoliosis patients (birth to 21 y) who underwent posterior spinal fusion at our institution from 2017 to 2018. We reported rates of blood loss and transfusion, compared patients receiving tranexamic acid to a ε-aminocaproic acid, and evaluated antifibrinolytic agent and laboratory parameters as predictors of blood loss and transfusion. Intraoperatively, 62% received tranexamic acid and 38% received ε-aminocaproic acid. Overall, blood loss (mean intraoperative estimated blood loss=14.9±9.7 mL/kg, 22% with clinically significant blood loss [>20 mL/kg], and mean calculated hemoglobin mass loss=175.9±70.1 g) and transfusion rates (15% with intraoperative allogeneic red blood cell transfusion and mean intraoperative allogeneic red blood cell transfusion volume=12.5±7.1 mL/kg) were similar to previous cohorts studying intraoperative antifibrinolytics. There was no difference in intraoperative estimated blood loss, clinically significant blood loss, calculated hemoglobin mass loss, or transfusion rates between the antifibrinolytic groups. Antifibrinolytic choice was not predictive of blood loss or transfusion. Routine hematologic laboratory parameters and antifibrinolytic choice were insufficient to predict blood loss or other outcomes. Future prospective laboratory-based studies may provide a more comprehensive model of surgical-induced coagulopathy in scoliosis surgery and provide a better tool for predicting blood loss and improving outcomes.

Perioperative blood conservation strategies for pediatric scoliosis surgery

PURPOSE

Many pediatric patients with severe scoliosis requiring surgery have baseline anemia. Pediatric scoliosis fusion surgery is associated with perioperative blood loss requiring transfusion. As such, many patients in this surgical population could benefit from a perioperative blood conservation program.

METHODS

Here we present a narrative review of perioperative blood conservation strategies for pediatric scoliosis surgery involving nurses, transfusion medicine physicians, anesthesiologists, surgeons, dieticians, perfusionists and neurophysiologists spanning the pre-, intra- and postoperative phases of care.

RESULTS

The review highlights how perioperative blood conservation strategies, have the potential to minimize exposures to exogenous blood products. Further, we describe a relevant example of blood conservation related to the care of a Jehovah's Witness patient undergoing staged scoliosis repair. Lastly, we outline areas which would benefit from clinical studies to further elucidate perioperative blood conservation interventions and their outcomes relevant to pediatric scoliosis surgery patients.

CONCLUSION

Interdisciplinary communication and meticulous blood conservation strategies are proving to be a means of reducing if not eliminating the need for allogeneic blood products for surgical correction of pediatric scoliosis.