Comparative-Effectiveness study evaluating outcomes for transforaminal epidural steroid injections performed with 3% hypertonic saline or normal saline in lumbosacral radicular pain.

BACKGROUND: Transforaminal epidural steroid injection (TFESI) are commonly employed to treat lumbosacral radiculopathy. Despite anti-inflammatory properties, the addition of 3% hypertonic saline has not been studied. OBJECTIVE: Compare the effectiveness of adding 0.9% NaCl (N-group) vs. 3% NaCl (H-group) in TFESI performed for lumbosacral radiculopathy. METHODS: This retrospective study compared TFESI performed with lidocaine, triamcinolone and 0.9% NaCl. The primary outcome was the proportion of patients who experienced a ≥ 30% reduction in pain on a verbal rating scale (VRS; 0-100) at 3 months. Secondary outcome measures included the proportion of patients who improved by at least 30% for pain at 1- and 6-months, and who experienced ≥15% from baseline on the Oswestry disability index (ODI) at follow-up. RESULTS: The H-group experienced more successful pain outcomes than the N-group at 3 months (59.09% vs. 41.51%; P = 0.002) but not at 1 month (67.53% vs. 64.78%; P = 0.61) or 6 months (27.13% vs 21.55%: P = 0.31). For functional outcome, there was a higher proportion of responders in the H-group than N-group at 3 months (70.31% vs. 53.46%; P = 0.002). Female, age ≤ 60 years and duration of pain ≤ 6 months were associated with superior outcomes at the 3-month endpoint. Although those with a herniated disc experienced better outcomes in general with TFESI, the only difference favoring the H-group was for spondylolisthesis patients. CONCLUSIONS: 3% hypertonic saline is a viable alternative to normal saline as an adjunct for TFESI, with randomized studies needed to compare its effectiveness to steroids as a possible alternative. REGISTRATION: Thai Clinical Trials Registry ID TCTR 20231110006.

Assessing the effectiveness of a digital, case-based learning platform for cancer pain management in residency training.

Objectives: To determine the effectiveness of self-directed, case-based learning in cancer pain management via a digital learning platform (e-CBL) in interdisciplinary residents' knowledge and critical thinking skill level. Methods: The prospective observational study was conducted on 51 first- and second-year residents from anesthesiology, surgery, and family medicine who had not received training in the management of cancer pain and were invited to participate by their Program Director. Participants voluntarily underwent e-CBL in cancer pain management using four modules (pain assessment, principles of pain management, pharmacological techniques, and non-pharmacological techniques) at their convenience within seven days via the Moodle platform. All participants underwent pre-and post-test assessments of knowledge and rated their satisfaction with the training on a 0-10 scale. Thirty-two residents completed Cornell Critical Thinking Test Level Z. Paired t-tests assessed changes, and the effect size was estimated by Cohen's d. A p-value < .05 was considered statistically significant. Results: Knowledge and critical thinking test results significantly improved after the training (M=68, SD=16.99 to M=86, SD=13.96 correct responses; t(50)=11.24, p<.001, Cohen's d=1.56 for knowledge) and (M=39.8, SD=13.7 vs. M=46.1, SD=10.2 correct responses; t(31)=-3.67, p=.001, Cohen's d=0.65 for critical thinking test). Satisfaction of learning experiences for convenience and understandability was high (M=9.4, SD=0.8). Conclusions: Use of the e-CBL improved knowledge in cancer pain management and critical thinking skills. This digital platform could play an important role in the future of pain education. Further investigation, including a control group, is warranted.

Cost-Effectiveness and Cost-Utility Analyses in Thailand of Continuous Intrathecal Morphine Infusion Compared with Conventional Therapy in Cancer Pain: A 10-year Multicenter Retrospective Study.

Background: Because of the high initial cost of intrathecal drug delivery (ITDD) therapy, this study investigated the cost-effectiveness and cost-utility of ITDD therapy in refractory cancer pain management in Thailand over the past 10 years. Methods: The retrospective study was conducted in patients with cancer pain who underwent ITDD therapy from January 2011 to 2021 at three university hospitals. Clinical outcomes included the numerical rating scale (NRS), Palliative Performance Scale, and the EQ-5D. The direct medical and nonmedical as well as indirect costs were also recorded. Cost-effectiveness and cost-utility analyses were performed comparing ITDD therapy with conventional therapy (extrapolated from costs of the same patient before ITDD therapy) from a societally oriented economic evaluation. Results: Twenty patients (F:M: 10:10) aged 60 ± 15 years who underwent implantation of an intrathecal percutaneous port (IT port; n = 15) or programmable intrathecal pump (IT pump; n = 5) were included. The median survival time was 78 (interquartile range = 121-54) days after ITDD therapy. At 2-month follow-up, the incremental cost-effectiveness ratio (ICER)/pain reduction of an IT port (US$2065.36 (CA$2829.54)/2-point NRS reduction/lifetime) was lower than for patients with an IT pump (US$5479.26 (CA$7506.58)/2-point NRS reduction/lifetime) compared with continued conventional therapy. The ICER/quality-adjusted life years (QALYs) gained for an IT port compared with conventional treatment was US$93,999.31(CA$128,799.06)/QALY gained, which is above the cost-effectiveness threshold for Thailand. Conclusion: The cost-effectiveness and cost-utility of IT port therapy for cancer pain was high relative to the cost of living in Thailand, above the cost-effectiveness threshold. Prospective cost analysis studies enrolling more patients with diverse cancers that investigate the benefit of early ITDD therapy with devices over a range of prices are warranted.

Contexte: En raison du coût initial élevé du traitement par administration intrathécale de médicaments (AIM), cette étude a étudié le rapport coût-efficacité et le rapport coût-utilité du traitement par AIM dans la prise en charge de la douleur cancéreuse réfractaire en Thaïlande au cours des 10 dernières années.Méthodes: L'étude rétrospective a été menée auprès de patients souffrant de douleur cancéreuse ayant subi un traitement par AIM de janvier 2011 et 2021 dans trois hôpitaux universitaires. Les résultats cliniques comprenaient l'échelle d'évaluation numérique (EEN), l'échelle de performance palliative et l'EQ-5D. Les coûts médicaux et non médicaux directs et indirects ont également été consignés. Les analyses coûts-efficacité et coût-utilité ont été effectuées en comparant le traitement par AIM au traitement conventionnel (extrapolé à partir des coûts pour le même patient avant le traitement par AIM) à partir d'une évaluation économique sociétale.Résultats: Vingt patients (F : M : 10 : 10) âgés de 60 ± 15 ans ayant subi l'implantation d'un port percutané intrathécal (port IT; n = 15) ou d'une pompe intrathécale programmable (pompe IT; n = 5) ont été inclus. Le temps de survie médian était de 78 jours (intervalle interquartile = 121­54) après le traitement par AIM. À deux mois de suivi, le ratio coût-efficacité incrémental (RCEI/réduction de la douleur d'un port IT (2 065,36 $ US (2 829,54 $ CA) /réduction de 2 points sur l'EEN/durée de vie) était inférieur à celui des patients avec une pompe IT (5479,26 $ US (7506,58 $ CA) /réduction de 2 points sur l'EEN/durée de vie) comparativement au traitement conventionnel en continu. Le RCEI/année de vie pondérée par la qualité (AVPQ) gagnée pour un port IT comparativement au traitement conventionnel était de 93 999,31 $ US (128 799,06 $ CA) /AVPQ gagné, ce qui est au-dessus du seuil de rentabilité pour la Thaïlande.Conclusion: Le rapport coût-efficacité et le rapport coût-utilité du traitement par port IT pour la douleur cancéreuse étaient élevés par rapport au coût de la vie en Thaïlande, soit au-dessus du seuil de rentabilité. Les études d'analyse de coût prospectives portant sur un plus grand nombre de patients atteints de divers cancers qui étudient les avantages des traitements par AIM précoces à l'aide d'appareils de prix différents sont justifiées.

Antimicrobial therapies for chronic pain (part 1): analgesic mechanisms.

There is increasing evidence that the relationship between chronic pain and infections is complex and intertwined. Bacterial and viral infections can cause pain through numerous mechanisms such as direct tissue damage and inflammation, the induction of excessive immunologic activity, and the development of peripheral or central sensitization. Treating infections might relieve pain by attenuating these processes, but a growing body of literature suggests that some antimicrobial therapies confer analgesic effects, including for nociceptive and neuropathic pain symptoms, and affective components of pain. The analgesic mechanisms of antimicrobials are indirect, but might be conceptualized into two broad categories: 1) the reduction of the infectious burden and associated pro-inflammatory processes; and 2) the inhibition of signaling processes (e.g., enzymatic and cytokine activity) necessary for nociception and maladaptive neuroplastic changes via off-target effects (unintended binding sites). For the former, there is evidence that symptoms of chronic low back pain (when associated with Modic type 1 changes), irritable bowel syndrome, inflammatory bowel disease, chronic pelvic pain, and functional dyspepsia might be improved after antibiotic treatment, though significant questions remain regarding specific regimens and dose, and which subpopulations are most likely to benefit. For the latter, there is evidence that several antimicrobial classes and medications exert analgesic effects independent of their reduction of infectious burden, and these include cephalosporins, ribavirin, chloroquine derivatives, rapalogues, minocycline, dapsone, and piscidin-1. This article aims to comprehensively review the existing literature for antimicrobial agents that have demonstrated analgesic efficacy in preclinical or clinical studies.

Antimicrobial therapies for chronic pain (part 2): the prevention and treatment of chronic pain.

The discovery and development of antimicrobial therapies represents one of the most significant advancements in modern medicine. Although the primary therapeutic intent of antimicrobials is to eliminate their target pathogens, several antimicrobials have been shown to provide analgesia as a secondary benefit. Antimicrobials have demonstrated analgesic effects in conditions that involve dysbiosis or potential subclinical infection (e.g ., chronic low back pain with Modic type 1 changes; chronic prostatitis/chronic pelvic pain; irritable bowel syndrome; inflammatory bowel disease; functional gastrointestinal disorders/dyspepsia; myalgic encephalomyelitis/chronic fatigue syndrome), and might even prevent the chronification of pain after acute infections that are associated with excessive systemic inflammation (e.g ., post COVID-19 condition/long Covid, rheumatic fever). Clinical studies often assess the analgesic effects of antimicrobial therapies in an observational manner, without the ability to identify causative relationships, and significant gaps in the understanding remain regarding the analgesic potential of antimicrobials. Numerous interrelated patient-specific, antimicrobial-specific, and disease-specific factors altogether contribute to the perception and experience of pain, and each of these requires further study. Given worldwide concerns regarding antimicrobial resistance, antimicrobials must continue to be used judiciously and are unlikely to be repurposed as primary analgesic medications. However, when equipoise exists among several antimicrobial treatment options, the potential analgesic benefits of certain antimicrobial agents might be a valuable aspect to consider in clinical decision-making. This article (the second in a two-part series) aims to comprehensively review the evidence on the prevention and treatment of chronic pain using antimicrobial therapies and suggest a framework for future studies on this topic.

Bipolar radiofrequency ablation of the superomedial (SM), superolateral (SL) and inferomedial (IM) genicular nerves for chronic osteoarthritis knee pain: a randomized double-blind placebo-controlled trial with 12-month follow-up.

BACKGROUND: Variability in anatomy in the knees supports the use of aggressive lesioning techniques such as bipolar-radiofrequency ablation (RFA) to treat knee osteoarthritis (KOA). There are no randomized controlled trials evaluating the efficacy of bipolar-RFA. METHODS: Sixty-four patients with KOA who experienced >50% pain relief from prognostic superomedial, superolateral and inferomedial genicular nerve blocks were randomly assigned to receive either genicular nerve local anesthetic and steroid injections with sham-RFA or local anesthetic and steroid plus bipolar-RFA. Participants and outcome adjudicators were blinded to allocation. The primary outcome was Visual Analog Scale pain score 12 months postprocedure. Secondary outcome measures included Western Ontario and McMaster Universities Arthritis (WOMAC) and Patient Global Improvement-Indexes (PGI-I). RESULTS: Both groups experienced significant reductions in pain, with no significant differences observed at 12 months (reduction from 5.7±1.9 to 3.2±2.6 in the RFA-group vs from 5.0±1.4 to 2.6±2.4 in the control-group (p=0.40)) or any other time point. No significant changes were observed between groups for WOMAC and PGI-I at the primary endpoint, with only the control group experiencing a significant improvement in function at 12-month follow-up (mean reduction from 91.2±38.2 to 67.1±51.9 in the RFA-group (p=0.06) vs from 95.8±41.1 to 60.6±42.8 in the control group (p=0.001); p=0.85 between groups). CONCLUSION: Our failure to find efficacy for genicular nerve RFA, coupled with evidence showing that a plenitude of nerves supply the knee joint and preliminary studies indicating superiority of lesioning strategies targeting more than three nerves, suggest controlled trials using more aggressive lesioning strategies are warranted. TRIAL REGISTRATION NUMBER: TCTR20170130003.

Chronic pain and infection: mechanisms, causes, conditions, treatments, and controversies.

Throughout human history, infection has been the leading cause of morbidity and mortality, with pain being one of the cardinal warning signs. However, in a substantial percentage of cases, pain can persist after resolution of acute illness, manifesting as neuropathic, nociplastic (eg, fibromyalgia, irritable bowel syndrome), or nociceptive pain. Mechanisms by which acute infectious pain becomes chronic are variable and can include immunological phenomena (eg, bystander activation, molecular mimicry), direct microbe invasion, central sensitization from physical or psychological triggers, and complications from treatment. Microbes resulting in a high incidence of chronic pain include bacteria such as the Borrelia species and Mycobacterium leprae, as well as viruses such as HIV, SARS-CoV-2 and herpeses. Emerging evidence also supports an infectious cause in a subset of patients with discogenic low back pain and inflammatory bowel disease. Although antimicrobial treatment might have a role in treating chronic pain states that involve active infectious inflammatory processes, their use in chronic pain conditions resulting from autoimmune mechanisms, central sensitization and irrevocable tissue (eg, arthropathy, vasculitis) or nerve injury, are likely to cause more harm than benefit. This review focuses on the relation between infection and chronic pain, with an emphasis on common viral and bacterial causes.

Pain experiences and intrapersonal change among patients with chronic non-cancer pain after using a pain diary: a mixed-methods study.

OBJECTIVE: Pain diaries are a valuable self-assessment tool; however, their use in chronic non-cancer pain has received limited attention. In this study, we examined the effect of pain diary use on pain intensity, interference, and intrapersonal change in patients with chronic non-cancer pain. METHOD: A convergent mixed-methods design was used to prospectively evaluate a cohort of 72 patients. Daily pain intensity and weekly pain-interference were self-reported using pain diaries for a 4-week period. Outcomes were assessed by examining changes in pain scores (primary outcome) as well as the Brief Pain Inventory and Short-form McGill Pain Questionnaire-2. In addition, qualitative data obtained from pain diary entries and focus-group interviews were analyzed using thematic content analysis. RESULTS: Pain intensity and average pain scores were significantly lower after using the diaries. Participants reported less pain interference in mood, walking ability, normal work, and enjoyment of life. No differences were found in SF-MPQ-2 scores. Qualitative analysis indicated that better pain recognition and more effective communication with care providers led to improved self-management and more effectual treatment plans. CONCLUSION: Use of a pain diary in patients with chronic non-cancer pain was associated with reduced pain intensity and improved mood as well as function. Further controlled trials examining the long-term effects of pain diaries are warranted.

Cervical Foraminal Epidural Blood Patch for the Targeted Treatment of Refractory Cerebrospinal Fluid Leakage From a Dural Sleeve.

Epidural blood patches (EBPs) are routinely used to treat symptoms (eg, headaches) associated with spontaneous intracranial hypotension. Although cerebrospinal fluid leakage commonly involves the periforaminal areas of the cervical or thoracic spine, EBPs have been historically performed at the lumbar level. Recent evidence suggests that targeting the causative spinal segment may provide greater clinical benefits. While previous reports have targeted foraminal leaks with segmental thoracic or cervical injections, we present a case report detailing the novel use of a navigable epidural catheter to perform a selective EBP at the C7/T1 foramen.

Parenteral Parecoxib Provides a Similar Reduction in Opioid Requirement to Single-Shot Sciatic Nerve Block after Total Knee Arthroplasty when Combined with Continuous Femoral Nerve Block.

Objective: Continuous femoral nerve blockade has become an accepted modality in the management of pain after total knee arthroplasty (TKA); however, posterior knee pain can be problematic and often requires additional analgesia. The present study compared the use of parenteral parecoxib to single-shot sciatic block for this purpose. Material and Method: After the Ethic Review Board gave approval, adults undergoing TKA were randomly divided into 3 groups. Group 1 (Gr-F+S) received single-shot sciatic nerve block (SNB) with 0.25% bupivacaine 25 ml in addition to continuous femoral analgesia (CFA) (0.125% bupivacaine 7 ml/h); group 2 (Gr-F+P) received parenteral parecoxib 40 mg q 12 hours with CFA; and group 3 (Gr-F) received only CFA. Assessments were performed at 0, 6, 12, and 24 hours post op. and included the following variables: NRS (numerical rating score) at rest, morphine use, time to first analgesic dose and side effects. Results: Seventy-eight patients were enrolled, with 26 participants in each of the 3 groups. There was no inter-group difference in pain score (NRS). However, morphine requirements in the first 24 hours were significantly increased in Gr-F (17±12 mg) when compared to Gr-F+S (10±7 mg) and Gr-F+P (9±5 mg) (p<0.001). There was no difference in time to first analgesic dose, side effects or patient satisfaction. Conclusion: Parenteral parecoxib and single-shot SNB both significantly reduced morphine requirements when used in combination with femoral nerve blockade after TKA.

Prolonged propofol anesthesia is not associated with an increase in blood lactate.

BACKGROUND: Lactic acidosis is considered an early sign of propofol infusion syndrome. In this study, we investigated the changes in lactate and pH with propofol versus volatile anesthesia (VA) of long duration. METHODS: Demographic and intraoperative data were recorded retrospectively from the anesthesia records of patients who underwent elective spine surgery longer than 8 h. Propofol patients were matched 1:2 to VA patients, based on anesthesia time (AT) (+/-30 min) and blood loss (BL) (+/-500 mL). RESULTS: Of 246 patients identified, 50 received propofol (AT = 10 +/- 2 h, BL = 1955 +/- 1409 mL) and were matched to 100 VA cases (AT = 10 +/- 1 h, BL = 1801 +/- 1543 mL), and of those, 40 and 72 patients, respectively, had complete lactate data at baseline and at 8 h after anesthesia and were included in the main analysis. The propofol group received 8.8 +/- 2 mg x kg(-1) x h(-1) of propofol. The VA group age was older than the propofol group (58 +/- 12 vs 51 +/- 15 yr, respectively, P = 0.002), but there was no difference between the groups in gender, ASA grade, intraoperative hemodynamic variables, and use of vasopressors. After 8 h, the VA group had a larger increase in arterial lactate from baseline compared with the propofol group (change from baseline: propofol, 0.48 +/- 0.72 mmol/L; VA, 1.2 +/- 1.2 mmol/L, P = 0.001). CONCLUSIONS: During prolonged spine surgery >8 h, VA was associated with higher serum lactate, when compared with propofol infusion. Prospective studies are needed to elucidate the exact mechanisms and clinical implications of this finding.

Hemispheric differences in cerebral autoregulation in children with moderate and severe traumatic brain injury.

INTRODUCTION: To examine hemispheric differences in cerebral autoregulation in children with traumatic brain injury (TBI). After IRB approval and consent, subjects underwent static cerebral autoregulation testing during the first 9 days after PICU admission. Cerebral autoregulation was quantified using the autoregulatory index (ARI). RESULTS: Forty-two (27 M:15 F) children (10 +/- 5 years) with TBI and admission Glasgow coma scale score (5 +/- 2) were enrolled. Seven (54%) of the 13 children with focal TBI and 8 (28%) of 29 children with diffuse TBI had impairment or absence of cerebral autoregulation of at least one hemisphere. In patients with isolated focal TBI, ARI was lower (0.40 +/- 0.40 vs. 0.67 +/- 0.40; P = 0.03) in the side of TBI than in the unaffected hemisphere, but cerebral autoregulation was often impaired on the side without TBI or shift (5/13) on head CT. There was no difference in ARI between hemispheres in children with diffuse TBI, with or without superimposed focal lesions (P = 0.17). Patients with bilateral intact cerebral autoregulation tended to have higher 6 month Glasgow Outcome Score (GOS) than patients with either unilateral or bilateral cerebral autoregulation impairment (GOS 4.0 +/- 0.60 vs. 3.6 +/- 0.80; P = 0.08). CONCLUSIONS: Hemispheric differences in cerebral autoregulation were common in children with isolated focal TBI. Absence of TBI on CT was not always associated with intact cerebral autoregulation. Patients with bilaterally intact cerebral autoregulation tended to have better outcomes.

Effect of equiosmolar solutions of mannitol versus hypertonic saline on intraoperative brain relaxation and electrolyte balance.

BACKGROUND: The purpose of the study was to compare the effect of equiosmolar solutions of mannitol and hypertonic saline (HS) on brain relaxation and electrolyte balance. METHODS: After institutional review board approval and informed consent, patients with American Society of Anesthesiologists physical status II-IV, scheduled to undergo craniotomy for various brain pathologies, were enrolled into this prospective, randomized, double-blind study. Patients received 5 ml/kg 20% mannitol (n = 20) or 3% HS (n = 20). Partial pressure of carbon dioxide in arterial blood was maintained at 35-40 mmHg, and central venous pressure was maintained at 5 mmHg or greater. Hemodynamic variables, fluid balance, blood gases, electrolytes, lactate, and osmolality (blood, cerebrospinal fluid, urine) were measured at 0, 15, 30, and 60 min and 6 h after infusion; arteriovenous difference of oxygen, glucose, and lactate were calculated. The surgeon assessed brain relaxation on a four-point scale (1 = relaxed, 2 = satisfactory, 3 = firm, 4 = bulging). Appropriate statistical tests were used for comparison; P < 0.05 was considered significant. RESULTS: There was no difference in brain relaxation (mannitol = 2, HS = 2 points; P = 0.8) or cerebral arteriovenous oxygen and lactate difference between HS and mannitol groups. Urine output with mannitol was higher than with HS (P < 0.03) and was associated with higher blood lactate over time (P < 0.001, compared with HS). Cerebrospinal fluid osmolality increased at 6 h in both groups (P < 0.05, compared with baseline). HS caused an increase in sodium in cerebrospinal fluid over time (P < 0.001, compared with mannitol). CONCLUSION: Mannitol and HS cause an increase in cerebrospinal fluid osmolality, and are associated with similar brain relaxation scores and arteriovenous oxygen and lactate difference during craniotomy.

The use of repeated head computed tomography in pediatric blunt head trauma: factors predicting new and worsening brain injury.

OBJECTIVE: Opinion is divided on the value of repeat head computed tomography for guiding clinical management of pediatric patients with blunt head trauma. This study describes the prevalence of worsening brain injury on repeat computed tomography, predictors of worsening computed tomography findings, and the frequency of neurosurgical intervention after the repeat computed tomography. DESIGN: Retrospective cohort study. SETTING: All patients were admitted to a level I pediatric trauma center between 1994 and 2003. PATIENTS: Children <15 yrs old with two or more head computed tomographies following hospital admission for blunt head trauma. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We reviewed the imaging reports to determine injury progression. Potential predictors of worsening computed tomography findings and neurosurgical intervention were recorded by chart review. Logistic regression and recursive partitioning were used to identify predictors. Twenty percent (50 of 257) of patients with mild head injury had worsening computed tomography findings, and three patients (1%) had subsequent neurosurgical intervention. Patients with moderate and severe head injuries were more likely to have worsening computed tomography findings (107 of 248; 43%) and to have neurosurgical intervention (15 of 248; 6%). In most surgical patients, repeat computed tomography was preceded by rapid decline in neurologic status or elevated intracranial pressure. Stratification based on four clinical factors (initial head injury severity, any intraparenchymal finding on initial computed tomography, normal findings on initial computed tomography, coagulopathy) identified 100% of the surgical patients and 89% of patients with worsening brain injuries on the repeat computed tomography. CONCLUSIONS: Repeat head computed tomography imaging is frequently used. About 30% of repeated computed tomographies showed new or worsening brain injury. However, worsening brain injury on repeat computed tomography rarely resulted in neurosurgical intervention. Patients with moderate or severe head injury and intraparenchymal injuries were more likely to show worsening brain injury and undergo neurosurgical intervention.

Change in cerebral autoregulation as a function of time in children after severe traumatic brain injury: a case series.

OBJECTIVE: The objective of this study was to describe changes in cerebral autoregulation after severe pediatric traumatic brain injury (TBI). MATERIALS AND METHODS: Two cerebral autoregulation tests were performed during the first 10 days after severe TBI in children <16 years. Cerebral autoregulation was quantified using the mean autoregulatory index (mARI). RESULTS: Nine (five males/four females) children (10 +/- 5 years) with severe (admission Glasgow Coma Scale (GCS), 5 +/- 2) TBI were enrolled. Thirty (3/9) percent of initial exams revealed impaired cerebral autoregulation; all three had returned to intact cerebral autoregulation on second exam. However, in three of nine (33%) patients, cerebral autoregulation worsened on second exam. Of the factors examined, worsening mARI on second exam was associated with worsening head computed tomography (CT) lesion. CONCLUSIONS: Cerebral autoregulation often changed and worsened during the first 9 days after severe pediatric TBI. Worsening cerebral autoregulation may mirror worsening TBI.

Early childhood gender differences in anterior and posterior cerebral blood flow velocity and autoregulation.

OBJECTIVE: We aimed to describe gender differences in blood flow velocity and autoregulation of the anterior and posterior cerebral circulations in prepubertal children. METHODS: A prospective observational cohort study was performed at Harborview Medical Center's Cerebrovascular Laboratory after institutional review board approval, consent, and assent procedures. Children underwent measurement of middle cerebral and basilar artery flow velocities and cerebral autoregulation testing of the middle cerebral and basilar arteries. Cerebral autoregulation was quantified using the autoregulatory index, and estimated cerebrovascular resistance was calculated. Autoregulatory index <0.4 reflects impaired cerebral autoregulation. Data are presented as mean +/- SD. Patients were healthy 4- to 8-year-old children. RESULTS: Forty-eight children (24 boys and 24 girls) 4 to 8 years of age (mean: 6 +/- 2 years) were enrolled. Middle cerebral artery flow velocity was higher than basilar artery flow velocity (96 +/- 13 vs 65 +/- 11 cm/s). Girls had higher middle cerebral artery flow velocity (99 +/- 11 vs 91 +/- 13 cm/s) and basilar artery flow velocity (70 +/- 10 vs 61 +/- 9 cm/s) than boys. Cerebral autoregulation was intact in all children. There was no gender difference in autoregulation between the middle cerebral artery (boys: 0.97 +/- 0.07; girls: 0.94 +/- 0.11) or basilar artery (boys: 0.94 +/- 0.13; girls: 0.94 +/- 0.11). CONCLUSIONS: Similar to older children and adults, girls between 4 and 8 years of age had higher middle cerebral and basilar artery flow velocity than age-matched boys. This difference may reflect inherent differences in cerebral metabolic rate and/or estimated cerebrovascular resistance between the genders.

Impaired cerebral autoregulation and 6-month outcome in children with severe traumatic brain injury: preliminary findings.

The objective of this study was to describe the incidence of impaired cerebral autoregulation and to describe the relationship between impaired cerebral autoregulation and outcome after severe pediatric traumatic brain injury (TBI). We prospectively examined cerebral autoregulation in 28 children