Catherine E. Ferland

Effects of Peritoneal Ropivacaine Nebulization for Pain Control After Laparoscopic Gynecologic Surgery

STUDY OBJECTIVE To evaluate the effects of peritoneal cold nebulization of ropivacaine on pain control after gynecologic laparoscopy. DESIGN Evidence obtained from a properly designed, randomized, double-blind, placebo-controlled trial (Canadian Task Force classification I). SETTING Tertiary care center. PATIENTS One hundred thirty-five women with American Society of Anesthesiologists disease classified as ASA I-III who were scheduled to undergo operative laparoscopy. INTERVENTION Patients were randomized to receive either nebulization of 30 mg ropivacaine before surgery (preoperative group), nebulization of 30 mg ropivacaine after surgery (postoperative group), instillation of 100 mg ropivacaine before surgery (instillation group), or instillation of saline solution (control group). Nebulization was performed using the Aeroneb Pro device. MEASUREMENT AND MAIN RESULTS Pain scores, morphine consumption, and ambulation time were collected in the post-anesthesia care unit and at 4, 6, and 24 hours postoperatively. One hundred eighteen patients completed the study. Patients in the preoperative group reported lower pain Numeric Ranking Scale values compared with those in the control group (net difference 2 points; 95% confidence interval [CI], 0.3-3.1 at 4 hours, 1-3 at 6 hours, and 0.7-3 at 24 hours; p = .01) Patients in the preoperative group consumed significantly less morphine than did those in the control group (net difference 7 mg; 95% CI, 0.7-13; p = .02). More patients who received nebulization walked without assistance within 12 hours after awakening than did those in the instillation and control groups (net difference 15%; 95% CI, 6%-24%; p = .001). CONCLUSIONS Cold nebulization of ropivacaine before surgery reduced postoperative pain and morphine consumption and was associated with earlier walking without assistance.

Preoperative Norepinephrine Levels in Cerebrospinal Fluid and Plasma Correlate With Pain Intensity After Pediatric Spine Surgery

PURPOSE Catecholamines were found to be involved in descending pain modulation and associated with perioperative pain. The purpose of the present study was to investigate the relationship between preoperative concentrations of catecholamines and postoperative pain intensity of pediatric patients. METHODS Fifty adolescents with idiopathic scoliosis scheduled for elective spinal fusion surgery were enrolled in this prospective cohort study. Preoperative plasma and cerebrospinal fluid (CSF) samples were collected and analyzed by mass spectrometry. Pain intensity was assessed during the acute postoperative period and in the intermediate period. RESULTS Preoperative plasma concentrations of norepinephrine (NE) and normetanephrine (NME), as well as the CSF concentration of NE, were significantly correlated with the presence of pain six weeks after surgery (r = 0.48, 0.50, and 0.50, respectively; p < .002). We also found that preoperative NE levels in CSF were significantly higher in patients reporting moderate to severe pain intensity than in patients with mild pain during the first day following surgery (0.268 ± 0.29 ng/mL vs. 0.121 ± 0.074 ng/mL, p = .01), as well as between patients reporting pain and painless patients at 6 weeks postsurgery (0.274 ± 0.282 ng/mL vs. 0.103 ± 0.046 ng/mL respectively, U = 69.5, p = .002). CONCLUSIONS These results support the potential role of catecholamine levels in predicting postoperative pain intensity.PURPOSE Catecholamines were found to be involved in descending pain modulation and associated with perioperative pain. The purpose of the present study was to investigate the relationship between preoperative concentrations of catecholamines and postoperative pain intensity of pediatric patients. METHODS Fifty adolescents with idiopathic scoliosis scheduled for elective spinal fusion surgery were enrolled in this prospective cohort study. Preoperative plasma and cerebrospinal fluid (CSF) samples were collected and analyzed by mass spectrometry. Pain intensity was assessed during the acute postoperative period and in the intermediate period. RESULTS Preoperative plasma concentrations of norepinephrine (NE) and normetanephrine (NME), as well as the CSF concentration of NE, were significantly correlated with the presence of pain six weeks after surgery (r = 0.48, 0.50, and 0.50, respectively; p < .002). We also found that preoperative NE levels in CSF were significantly higher in patients reporting moderate to severe pain intensity than in patients with mild pain during the first day following surgery (0.268 ± 0.29 ng/mL vs. 0.121 ± 0.074 ng/mL, p = .01), as well as between patients reporting pain and painless patients at 6 weeks postsurgery (0.274 ± 0.282 ng/mL vs. 0.103 ± 0.046 ng/mL respectively, U = 69.5, p = .002). CONCLUSIONS These results support the potential role of catecholamine levels in predicting postoperative pain intensity.

Bilateral vascularized rib grafts to promote spinopelvic fixation in patients with sacral agenesis and spinopelvic dissociation: a new surgical technique

BACKGROUND CONTEXT Sacral agenesis is a rare congenital disorder that may have spinopelvic instability due to sacroiliac joint malformation. Surgical indication in patients with sacral agenesis is to improve their sitting balance and protect the visceral organs. Achieving solid arthrodesis across this congenital malformation is challenging and prone to non-union. PURPOSE The purpose of this study was to describe a novel surgical technique with vascularized ribs for management of sacral agenesis and complex spinopelvic dissociation. STUDY DESIGN Retrospective study. PATIENT SAMPLE Six patients with sacral agenesis were reviewed and followed for a mean of 8.5 years after spinopelvic fusion augmented with vascularized rib graft spanning the lumbo-pelvic junction. OUTCOME MEASURES The primary outcome measure was the presence or absence of a stable spinopelvic junction and fusion across the spine-vascular rib grafts-pelvis interface. The secondary outcome measures were maintenance of pelvic obliquity, lumbosacral kyphosis, and overall sagittal balance. METHODS The surgical procedure consisted of two-stage surgeries performed 6-12 weeks apart. The first stage consisted of spinal instrumentation and correction of the deformity via a posterior approach and impaction of one of the vascularized ribs from the spine to the iliac crest. The second stage consisted of an anterior thoraco-lumbar approach for spinal fusion and the second vascularized rib spanning the spine to the iliac crest. RESULTS All six patients eventually achieved a solid spinal and spinopelvic fusion. All vascularized ribs increased in diameter over time. A high complication rate consisted mainly of spinal infections and prominent hardware requiring revision surgeries (a total of seven procedures in four patients). Two patients had decreased mobility secondary to spinopelvic surgery at last follow-up. CONCLUSIONS Spinopelvic fusion can be successfully achieved with this novel surgical technique using vascularized rib grafts. This technique allows for biological long-term maintenance of the sagittal deformity correction. Fusion across the lumbosacral junction in patients with sacral agenesis may place them at risk of losing the ability to mobilize independently. Recent lower profile implants have prevented implant-related complications.

EVIDENCE OF IMPAIRED PAIN MODULATION IN ADOLESCENTS WITH IDIOPATHIC SCOLIOSIS AND CHRONIC BACK PAIN

BACKGROUND CONTEXT Although 40% of adolescent idiopathic scoliosis (AIS) patients present with chronic back pain, the pathophysiology and underlying pain mechanisms remain poorly understood. We hypothesized that development of chronic pain syndrome in AIS is associated with alterations in pain modulatory mechanisms. PURPOSE To identify the presence of sensitization in nociceptive pathways and to assess the efficacy of the diffuse noxious inhibitory control in patients with AIS presenting with chronic back pain. STUDY DESIGN Cross-sectional study. PATIENT SAMPLE Ninety-four patients diagnosed with AIS and chronic back pain. OUTCOME MEASURES Quantitative sensory testing (QST) assessed pain modulation and self-reported questionnaires were used to assess pain burden and health-related quality of life. METHODS Patients underwent a detailed pain assessment using a standard and validated quantitative sensory testing (QST) protocol. The measurements included mechanical detection thresholds (MDT), pain pressure threshold (PPT), heat pain threshold (HPT), heat tolerance threshold (HTT), and a conditioned pain modulation (CPM) paradigm. Altogether, these tests measured changes in regulation of the neurophysiology underlying the nociceptive processes based on the patients pain perception. Funding was provided by The Louise and Alan Edwards Foundation and The Shriners Hospitals for Children. RESULTS Efficient pain inhibitory response was observed in 51.1% of patients, while 21.3% and 27.7% had sub-optimal and inefficient CPM, respectively. Temporal summation of pain was observed in 11.7% of patients. Significant correlations were observed between deformity severity and pain pressure thresholds (p=.023) and CPM (p=.017), neuropathic pain scores and pain pressure thresholds (p=.015) and temporal summation of pain (p=.047), and heat temperature threshold and pain intensity (p=.048). CONCLUSIONS Chronic back pain has an impact in the quality of life of adolescents with idiopathic scoliosis. We demonstrated a high prevalence of impaired pain modulation in this group. The association between deformity severity and somatosensory dysfunction may suggest that spinal deformity can be a trigger for abnormal neuroplastic changes in this population contributing to chronic pain syndrome.

Modern Trolley Growth Guidance for Early Onset Scoliosis

Successful management of early onset scoliosis lies in the prevention of curve progression while still maintaining spinal growth. Current treatment modalities can be classified based on the corrective forces placed across the growing spine. The classical posterior-based dual growing rods require repetitive distraction forces mainly across the concavity. In contrast, passive anterior tethering procedure applies compressive forces across the convexity. A third technique, modern Luque trolley, promotes growth guidance by achieving maximal apical control and apical translation, attempting to normalize axial spinal growth. The construct attempts to normalize Hueter-Volkmann forces across the vertebral growth plates and allows for the patient’s own spinal growth to expand the spinal implants while maintaining the apex of the deformity midline. An immediate benefit of such a construct is that it does not require repetitive surgeries. The modern Luque trolley construct relies on apical gliding spinal anchors while solid proximal and distal fixation holds each a set of two rods. Great care must be taken during spinal implantation to avoid periosteal exposure leading to spontaneous fusion. Not all early onset scoliosis can be treated with this technique. To ensure predictable outcome, patients need to have flexible curves allowing the apex to be placed back in midline optimizing axial growth.

Perioperative Pain Assessment in a 14-Year-Old Boy with Lumbar Disc Herniation

This case report illustrates the value of a comprehensive perioperative pain assessment composed of quantitative sensory testing and self-reported measures that highlight the impact of pain experienced by a 14-year-old boy suffering from chronic low back pain and sciatica. Before surgery, the pain assessment revealed inefficient endogenous inhibitory pain control with presence of temporal summation of pain. The severe pain was constant and lasted for 18 months. The patient was in a high-anxiety state, and reported significant functional disability and poor sleep quality. Six months after surgery, the patient was pain free. Quantitative sensory testing showed an improvement in his inhibitory pain control with the absence of temporal summation of pain. The patient was no longer anxious, was back to normal functional abilities, and reported good sleep quality. By including neurophysiology and other pain measures, the clinical application of a comprehensive pain assessment can provide objective measurements of treatment efficacy.

Blood monoamines as potential biomarkers for conditioned pain modulation efficacy: An exploratory study in paediatrics

Monoaminergic pathways are involved in the process of pain inhibition and facilitation. The objective of this study was to investigate the role of blood monoamines as biomarkers of conditioned pain modulation (CPM) efficacy.

Preoperative Norepinephrine Levels in Cerebrospinal Fluid and Plasma of Pediatric Patients Predict Postoperative Pain Intensity after Spinal Fusion Surgery

Introduction The purpose of the present study was to investigate if preoperative concentrations of monoamine neurotransmitters that are known to be involved in descending pain modulation are associated with perioperative pain intensity in a pediatric cohort of patients with idiopathic scoliosis scheduled for elective spinal fusion surgery. Material and Methods Patients scheduled to undergo spinal surgery for Adolescent Idiopathic Scoliosis (AIS) between the ages of 12 and 18 years were recruited from the outpatient clinic of the Shriners Hospital for Children (n = 50). Plasmatic and cerebrospinal fluid concentrations of epinephrine (EPI), norepinephrine (NE), and their respective metabolite metanephrine (ME) and normetanephrine (NME), were assessed. Five mL of blood were collected for study analysis in an EDTA-coated collection tube after the anesthesia induction. Prior to the intratechal epimorphine injection, 2 mL of cerebrospinal fluid was collected in a low binding protein tube. Monoamine neurotransmitters were derivatized by reductive diethylation analyzed by liquid chromatography coupled with tandem mass spectrometry on TripleTOF 5600 mass spectrometer. At all time points throughout the study (preoperative, first postoperative 24 hours = postoperative day 1 (POD1), second 24 hours = postoperative day 2 (POD2) and postoperative 6 weeks follow-up visit), pain intensity was rated with the use of the Faces Pain Scale-Revised (FPS-R). Linear regressions were performed to assess the predictive role of catecholamine levels for postoperative pain. The Mann-Whitney-U test was used to assess differences in baseline characteristics between patients reporting presence of pain and pain-free patients as well as for all other comparisons other than correlations. Results Our results demonstrate that patients reporting persistent postsurgical pain 6 weeks after surgery have greater preoperative peripheral and/or central norepinephrine (NE) and normetanephrine levels when compared with patients reporting no pain at follow-up. Likewise, in the acute postoperative period, patients reporting moderate-to-severe pain intensity had higher preoperative central NE levels. Conclusion These results support the evidence for a potential role of catecholamine levels in predicting postoperative pain intensity and sympathetically maintained pain, which could place pediatric patients at risk for the development of chronic postsurgical pain. Incidence and severity of persistent postoperative pain may be reduced by specific NE preoperative interventions.

Evaluation of the Modern Luque Trolley Construct for the Treatment of Early-onset Scoliosis Using a Gliding Implant in an Immature Animal Model.

Study Design: This was an experimental animal study. Objective: To determine biological compatibility, stability, and growth potential of the Trolley Gliding Vehicle (TGV) used in a novel surgical technique for guided spinal growth. Summary of Background Data: Current treatments for early-onset scoliosis maintaining spinal growth consist of posteriorly based spinal constructs requiring repetitive lengthening. Such interventions have a high rate of complications. Using a muscle-sparing technique, a modified dual-growing rods construct, and new sliding spinal anchors, we aimed to test a modern Luque Trolley construct in an immature animal model. Materials and Methods: Six matched pairs of 3-month-old lambs were randomized to an observation or a surgical group and were followed for 9 months. The surgical group was subjected to implantation of a modern Luque Trolley construct with the new TGV inserted using a minimally invasive transmuscular technique capturing the spine and the 2 overlapping rods on either side. Physical examinations and imaging were performed at routine intervals, with a subsequent necropsy. Results: The spines of the study group grew 96% between the instrumented segments compared with the control group without evidence of implant failure. In total, 42% of the fixed anchors (pedicle screws) and 13.90% of the TGV were loose. All 6 animals had some heterotrophic bone formation tracking along the rods (<20%) mainly originating from the distal anchor point. We identified 19 unplanned spontaneous facet arthrodesis out of the 132 mobile facets found between the fixed proximal and distal anchors. An additional 10 facets spontaneously fused proximal to the most proximal instrumented implants. Conclusions: Implantation of a modern Luque construct with TGV allows for spinal growth in a nonscoliotic animal model. Implant loosening was likely mechanical as no signs of reactive inflammatory reaction were found. Reduction of heterotrophic ossification and spontaneous facet arthrodesis remains a challenge in the management of immature spine.