Ventilation rates measured by capnography during out-of-hospital cardiac arrest resuscitations and their association with return of spontaneous circulation.

BACKGROUND: Clinical guidelines for adult out-of-hospital cardiac arrest (OHCA) recommend a ventilation rate of 8-10 per minute yet acknowledge that few data exist to guide recommendations. The goal of this study was to evaluate the utility of continuous capnography to measure ventilation rates and the association with return of spontaneous circulation (ROSC). METHODS: This was a retrospective observational cohort study. We included all OHCA during a two-year period and excluded traumatic and pediatric patients. Ventilations were recorded using non-invasive continuous capnography. Blinded medically trained team members manually annotated all ventilations. Four techniques were used to analyze ventilation rate. The primary outcome was sustained prehospital ROSC. Secondary outcomes were vital status at the end of prehospital care and survival to hospital admission. Univariable and multivariable logistic regression models were constructed. RESULTS: A total of 790 OHCA were analyzed. Only 386 (49%) had useable capnography data. After applying inclusion and exclusion criteria, the final study cohort was 314 patients. The median ventilation rate per minute was 7 (IQR 5.4-8.5). Only 70 (22%) received a guideline-compliant ventilation rate of 8-10 per minute. Sixty-two (20%) achieved the primary outcome. No statistically significant associations were observed between any of the ventilation parameters and patient outcomes in both univariable and multivariable logistic regression models. CONCLUSIONS: We failed to detect an association between intra-arrest ventilation rates measured by continuous capnography and proximal patient outcomes after OHCA. Capnography has poor reliability as a measure of ventilation rate. Achieving guideline-compliant ventilation rates remains challenging.

An In Vitro Biomechanical Evaluation of a Lateral Lumbar Interbody Fusion Device With Integrated Lateral Modular Plate Fixation.

STUDY DESIGN: In vitro cadaveric biomechanical study. OBJECTIVE: Biomechanically characterize a novel lateral lumbar interbody fusion (LLIF) implant possessing integrated lateral modular plate fixation (MPF). METHODS: A human lumbar cadaveric (n = 7, L1-L4) biomechanical study of segmental range-of-motion stiffness was performed. A ±7.5 Ncm moment was applied in flexion/extension, lateral bending, and axial rotation using a 6 degree-of-freedom kinematics system. Specimens were tested first in an intact state and then following iterative instrumentation (L2/3): (1) LLIF cage only, (2) LLIF + 2-screw MPF, (3) LLIF + 4-screw MPF, (4) LLIF + 4-screw MPF + interspinous process fixation, and (5) LLIF + bilateral pedicle screw fixation. Comparative analysis of range-of-motion outcomes was performed between iterations. RESULTS: Key biomechanical findings: (1) Flexion/extension range-of-motion reduction with LLIF + 4-screw MPF was significantly greater than LLIF + 2-screw MPF (P < .01). (2) LLIF with 2-screw and 4-screw MPF were comparable to LLIF with bilateral pedicle screw fixation in lateral bending and axial rotation range-of-motion reduction (P = 1.0). (3) LLIF + 4-screw MPF and supplemental interspinous process fixation range-of-motion reduction was comparable to LLIF + bilateral pedicle screw fixation in all directions (P ≥ .6). CONCLUSIONS: LLIF with 4-screw MPF may provide inherent advantages over traditional 2-screw plating modalities. Furthermore, when coupled with interspinous process fixation, LLIF with MPF is a stable circumferential construct that provides biomechanical utility in all principal motions.

Biomechanical Analysis of an Interspinous Process Fixation Device with In Situ Shortening Capabilities: Does Spinous Process Compression Improve Segmental Stability?

OBJECTIVE: The objective of this study was to characterize the biomechanical implications of spinous process compression, via in situ shortening of a next-generation interspinous process fixation (ISPF) device, in the context of segmental fusion. METHODS: Seven lumbar cadaveric spines (L1-L4) were tested. Specimens were first tested in an intact state, followed by iterative instrumentation at L2-3 and subsequent testing. The order followed was 1) stand-alone ISPF (neutral height); 2) stand-alone ISPF (shortened in situ from neutral height; shortened); 3) lateral lumbar interbody fusion (LLIF) + ISPF (neutral); 4) LLIF + ISPF (shortened); 5) LLIF + unilateral pedicle screw fixation; 6) LLIF + bilateral pedicle screw fixation. A 7.5-Nm moment was applied in flexion/extension, lateral bending, and axial rotation via a kinematic test frame. Segmental range of motion (ROM) and lordosis were measured for all constructs. Comparative analysis was performed. RESULTS: Statistically significant flexion/extension ROM reductions: all constructs versus intact condition (P < 0.01); LLIF + ISPF (neutral and shortened) versus stand-alone ISPF (neutral and shortened) (P < 0.01); LLIF + USPF versus ISPF (neutral) (P = 0.049); bilateral pedicle screw fixation (BPSF) versus stand-alone ISPF (neutral and shortened) (P < 0.01); LLIF + BPSF versus LLIF + unilateral pedicle screw fixation (UPSF) (P < 0.01). Significant lateral bending ROM reductions: LLIF + ISPF (neutral and shortened) versus intact condition and stand-alone ISPF (neutral) (P < 0.01); LLIF + UPSF versus intact condition and stand-alone ISPF (neutral and shortened) (P < 0.01); LLIF + BPSF versus intact condition and all constructs (P < 0.01). Significant axial rotation ROM reductions: LLIF + ISPF (shortened) and LLIF + UPSF versus intact condition and stand-alone ISPF (neutral) (P ≤ 0.01); LLIF + BPSF versus intact condition and all constructs (P ≤ 0.04). CONCLUSIONS: In situ shortening of an adjustable ISPF device may support increased segmental stabilization compared with static ISPF.

A Biomechanical Evaluation of a Next-Generation Integrated and Modular ACDF Device Possessing Full-Plate, Half-Plate, and No-Profile Fixation Iterations.

STUDY DESIGN: In vitro biomechanical study. OBJECTIVES: The objective of this in vitro biomechanical range-of-motion (ROM) study was to evaluate spinal segmental stability following fixation with a novel anterior cervical discectomy and fusion (ACDF) device ("novel device") that possesses integrated and modular no-profile, half-plate, and full-plate fixation capabilities. METHODS: Human cadaveric (n = 18, C3-T1) specimens were divided into 3 groups (n = 6/group). Each group would receive one novel device iteration. Specimen terminal ends were potted. Each specimen was first tested in an intact state, followed by anterior discectomy (C5/C6) and iterative instrumentation. Testing order: (1) novel device (group 1, no-profile; group 2, half-plate; group 3, full-plate); (2) novel device (all groups) with lateral mass screws (LMS); (3) traditional ACDF plate + cage; (4) traditional ACDF plate + cage + LMS. A 2 N·m moment was applied in flexion/extension (FE), lateral bending (LB), and axial rotation (AR) via a kinematic testing machine. Segmental ROM was tracked and normalized to intact conditions. Comparative statistical analyses were performed. RESULTS: Key findings: (1) the novel half- and full-plate constructs provided comparable reduction in FE and LB ROM to that of traditional plated ACDF (P ≥ .05); (2) the novel full-plate construct significantly exceeded all other anterior-only constructs (P ≤ .05) in AR ROM reduction; and (3) the novel half-plate construct significantly exceeded the no-profile construct in FE (P < .05). CONCLUSIONS: The novel ACDF device may be a versatile alternative to traditional no-profile and independent plating techniques, as it provides comparable ROM reduction in all principle motion directions, across all device iterations.

Victimizing behaviour among juvenile and young offenders: how different are perpetrators?

This study examined the victimizing behaviours of incarcerated juvenile and young offenders. A total of 108 juveniles and young offenders completed questionnaires relating to victimizing behaviours and were administered the Custodial Adjustment Questionnaire (CAQ: Thornton, 1987 In Applying Psychology to Imprisonment: Theory and Practice, McGurk B.J., Thornton, D. and Williams, M. (Eds). London: HMSO, pp. 445-465) and Hostility and Direction of Hostility Questionnaire (HDHQ: Caine et al., 1967. Manual of the Hostility and Direction of Hostility Questionnaire. London: University of London press). It was found that 50.9% of all respondents reported victimizing others, with verbal assaults and threats being the most common form of such behaviours. Furthermore, staff-identified "victimizers" were significantly more likely to report victimizing behaviour than the rest of the sample. Those who had been in custody longer were more likely to report victimizing others, as were younger offenders (15-17-year olds as compared to 18-21-year olds). Victimizers were also more likely to report having previously experienced victimization themselves. On the psychometric measures, self-reported victimizers scored significantly higher on the deviance sub-scale of the CAQ, and on a number of the sub-scales of the HDHQ. These findings are discussed in terms of previous literature and their practical implications considered.