Mark J. McVey

Children requiring spine surgery are often iron deficient and anemic. Pediatric spine surgery is associated with notable risk of perioperative acute blood loss. To manage acute blood loss, many pediatric patients undergoing spine surgery require allogeneic transfusion of blood products. Both anemia and blood transfusions are associated with morbidity, such as increased length of stay, perioperative costs, and rarely mortality. To mitigate these factors, applying ever evolving concepts related to patient blood management (PBM), blood conservation techniques (BCT), and enhanced recovery after surgery (ERAS) are effective means to reduce anemia and transfusions perioperatively during spine surgery. This review focuses on development of multidisciplinary teams to harness the potential of PBM, BCT, and ERAS strategies. PBM, BCT, and ERAS concepts applied perioperatively for pediatric patients undergoing spine surgery provide a means of mitigating anemia and reducing the requirement for blood transfusions.

Background and Objectives: Respiratory transfusion reactions associate strongly with morbidity and mortality, and transfusion‐associated circulatory overload (TACO) is the leading cause of reaction‐related deaths. Risk factors for TACO include transfusion speed and volume and cardiorenal comorbidities.Materials and Methods: An academic health network haemovigilance database was interrogated to assess variables associating with 371 cases of TACO and involved‐visit outcomes, using univariate and multivariate regression analysis.Results: TACO reactions over 11 years were reported in 179 males and 192 females, median age (interquartile range) 65 (53–75) years. In‐hospital and 28‐day mortality were 17.5% and 12.9%, respectively. In univariate regression modelling, male sex, injury severity grade, product volume administered, the use of platelets and intensive care admissions were each associated with in‐hospital and 28‐day mortality (p < 0.05). However, after multivariate regression analysis, only male sex in transfusion recipients independently associated with mortality (p < 0.05).Conclusion: In this cohort, male recipient sex and platelet administration were associated with TACO‐involving admissions not ending in survival.

Transfusion-related acute lung injury (TRALI) though relatively rare represents a severe lung injury. The sphingolipid sphingosine-1-phosphate (S1P) regulates the severity of platelet-mediated TRALI. Female platelet transfusion recipient plasmas or stored platelets from female donors have higher S1P levels than males, which reduces TRALI. Cold storage of murine platelets preserves platelet-S1P, which reduces TRALI in platelet-transfused recipients.

Introduction Pedicle screws are the primary method of vertebral fixation in scoliosis surgery, but there are lingering concerns over potential malposition. The rates of pedicle screw malposition in pediatric spine surgery vary from 10% to 21%. Malpositioned screws can lead to potentially catastrophic neurological, vascular, and visceral complications. Pedicle screw positioning in patients with neuromuscular scoliosis is challenging due to a combination of large curves, complex pelvic anatomy, and osteopenia. This study aimed to determine the rate of pedicle screw malposition, associated complications, and subsequent revision from screws placed with the assistance of machine vision navigation technology in patients with neuromuscular scoliosis undergoing posterior instrumentation and fusion. Method A retrospective analysis of the records of patients with neuromuscular scoliosis who underwent thoracolumbar pedicle screw insertion with the assistance of machine-vision image guidance navigation was performed. Screws were inserted by either a staff surgeon, orthopaedic fellow, or orthopaedic resident. Post-operative ultra-low dose CT scans were used to assess pedicle screw accuracy. The Gertzbein classification was used to grade any pedicle breaches (grade 0, no breach; grade 1, 4 mm). A screw was deemed accurate if no breach was identified (grade 0). Results 25 patients were included in the analysis, with a mean age of 13.6 years (range 11 to 18 years; 13/25 (52.0%) were female. The average pre-operative supine Cobb angle was 90.0 degrees (48–120 degrees). A total of 687 screws from 25 patients were analyzed (402 thoracic, 241 lumbosacral, 44 S2 alar-iliac (S2AI) screws). Surgical trainees (fellows and orthopaedic residents) inserted 46.6% (320/687) of screws with 98.8% (4/320) accuracy. The overall accuracy of pedicle screw insertion was 98.0% (Grade 0, no breach). All 13 breaches that occurred in the thoracic and lumbar screws were Grade 1. Of the 44 S2AI screws placed, one screw had a Grade 3 breach (2.3%) noted on intra-operative radiographs following rod placement and correction. This screw was subsequently revised. None of the breaches resulted in neuromonitoring changes, vessel, or visceral injuries. Conclusion Machine vision navigation technology combined with careful free-hand pedicle screw insertion techniques demonstrated high levels of pedicle screw insertion accuracy, even in patients with challenging anatomy.

Respiratory transfusion reactions represent some of the most severe adverse reactions related to receiving blood products. Of those, transfusion-related acute lung injury (TRALI) is associated with elevated morbidity and mortality. TRALI is characterized by severe lung injury associated with inflammation, pulmonary neutrophil infiltration, lung barrier leak, and increased interstitial and airspace edema that cause respiratory failure. Presently, there are few means of detecting TRALI beyond clinical definitions based on physical examination and vital signs or preventing/treating TRALI beyond supportive care with oxygen and positive pressure ventilation. Mechanistically, TRALI is thought to be mediated by the culmination of two successive proinflammatory hits, which typically comprise a recipient factor (1st hit—e.g., systemic inflammatory conditions) and a donor factor (2nd hit—e.g., blood products containing pathogenic antibodies or bioactive lipids). An emerging concept in TRALI research is the contribution of extracellular vesicles (EVs) in mediating the first and/or second hit in TRALI. EVs are small, subcellular, membrane-bound vesicles that circulate in donor and recipient blood. Injurious EVs may be released by immune or vascular cells during inflammation, by infectious bacteria, or in blood products during storage, and can target the lung upon systemic dissemination. This review assesses emerging concepts such as how EVs: 1) mediate TRALI, 2) represent targets for therapeutic intervention to prevent or treat TRALI, and 3) serve as biochemical biomarkers facilitating TRALI diagnosis and detection in at-risk patients.

It is a historic and common practice while performing spine surgery on patients with a VNS has been to have the patient’s neurologist turn off the VNS generator in the pre-operative anesthetic care unit and to use bipolar rather than monopolar electrocautery. Here we report a case of a 16-year-old male patient with cerebral palsy and refractory epilepsy managed with an implanted VNS who had scoliosis surgery (and subsequent hip surgery) conducted with the use of monopolar cautery. Although VNS manufacturer guidelines suggest that monopolar cautery should not be avoided, perioperative care providers should consider its selective use in high-risk instances (with greater risks of morbidity and mortality due to blood loss which outweigh the risk of surgical re-insertion of a VNS) such as cardiac or major orthopedic surgery. Considering the number of patients with VNS devices presenting for major orthopedic surgery is increasing, itis important to have an approach and strategy for perioperative management of VNS devices.

Background: Cardiorespiratory transfusion reactions drive most transfusion-related morbidity and mortality. Transfusion-associated circulatory overload and transfusion-related acute lung injury have established causes, important impacts, mitigation options, and revised definitions, while non-conforming CRTRs fall into a category known as transfusion-associated dyspnea. Though procedures to investigate high-risk febrile transfusion reactions are typically rooted in detecting incompatibility or bacterial contamination, a common standard for examining CRTRs is lacking. CRTRs are further challenged by charting limitations, confounding (or enhanced susceptibility) by comorbidities, and/or overlapping insults. Deeper profiling of CRTRs could improve categorizations, reveal best-value diagnostics, and decipher the nature of (and/or minimize) reactions coded as TAD. Methods: The primary objective of this multi-center study is to reduce uncertainty in final conclusions drawn on CRTRs (cases), defined by dyspnea with objective disturbances and/or significant hemodynamic insults, with/without fever (±F). HRFTRs (controls) represent higher-grade F (T≥39°C or chills/rigors or lower-grade F (≥38°C by +Δ1°C) with non-respiratory effects). Patients (goal: 200) consent to additional sampling (≤24h post-TR) to identify contributing factors in case/control presentations, and in diagnostic groups (TRALI, TACO±F, TAD). Mechanistic axes of interest are cardiorenal, hemolytic, leukoagglutinating, biolipid, vasoactive, and inflammatory. Secondary goals include elucidation of real-life “insult-multiplicity” in CRTRs, tests of greatest yield, and distinguishing features in TRALI/TACO/TAD. Conclusions: A deep systematic CRTR probe may not only reduce diagnostic uncertainty but frame biomarker performance and pathologic signatures in definition-specific CRTRs. The re-classifiability or biology of TAD may be better understood. High-quality, mechanistic, true-to-quantity hemovigilance better exposes burdens and management options. Trial Registration: The trial is registered with ClinicalTrials.gov. with registry number NCT04267029.