Effect of Intrawound Vancomycin Powder in Operatively Treated High-risk Tibia Fractures: A Randomized Clinical Trial

Importance

Despite the widespread use of systemic antibiotics to prevent infections in surgically treated patients with fracture, high rates of surgical site infection persist.

Objective

To examine the effect of intrawound vancomycin powder in reducing deep surgical site infections.

Design, Setting, and Participants

This open-label randomized clinical trial enrolled adult patients with an operatively treated tibial plateau or pilon fracture who met the criteria for a high risk of infection from January 1, 2015, through June 30, 2017, with 12 months of follow-up (final follow-up assessments completed in April 2018) at 36 US trauma centers.

Interventions

A standard infection prevention protocol with (n = 481) or without (n = 499) 1000 mg of intrawound vancomycin powder.

Main Outcomes and Measures

The primary outcome was a deep surgical site infection within 182 days of definitive fracture fixation. A post hoc comparison assessed the treatment effect on gram-positive and gram-negative-only infections. Other secondary outcomes included superficial surgical site infection, nonunion, and wound dehiscence.

Results

The analysis included 980 patients (mean [SD] age, 45.7 [13.7] years; 617 [63.0%] male) with 91% of the expected person-time of follow-up for the primary outcome. Within 182 days, deep surgical site infection was observed in 29 of 481 patients in the treatment group and 46 of 499 patients in the control group. The time-to-event estimated probability of deep infection by 182 days was 6.4% in the treatment group and 9.8% in the control group (risk difference, -3.4%; 95% CI, -6.9% to 0.1%; P = .06). A post hoc analysis of the effect of treatment on gram-positive (risk difference, -3.7%; 95% CI, -6.7% to -0.8%; P = .02) and gram-negative-only (risk difference, 0.3%; 95% CI, -1.6% to 2.1%; P = .78) infections found that the effect of vancomycin powder was a result of its reduction in gram-positive infections.

Conclusions and Relevance

Among patients with operatively treated tibial articular fractures at a high risk of infection, intrawound vancomycin powder at the time of definitive fracture fixation reduced the risk of a gram-positive deep surgical site infection, consistent with the activity of vancomycin.

Trial Registration

ClinicalTrials.gov Identifier: NCT02227446.

0090 Stage-Specific Sleep Disruption and its Effect on Spatial Navigational Memory

Introduction

The mechanisms by which sleep disruption impact memory may depend on sleep stage, as rapid eye movement (REM) and slow wave sleep (SWS) differ in several significant ways, including degree of neuronal synchrony and frequency of cortical local field potential oscillations. Here we sought to examine the relationship between stage-specific disruption of sleep and its effect on spatial navigational memory.

Methods

9 healthy adult subjects participated in this study which involved 3 in-lab polysomnograms (normal, REM-disruption, and SWS-disruption) accompanied by pre- and post-sleep functional neuroimaging of brain during a spatial navigational memory task. Graded auditory stimuli consisting of 0.5 second bursts of high-frequency tones (300-3000Hz) were used to disrupt sleep (REM/SWS) in real time. Primary metrics to ascertain the effect of these auditory tones on sleep were time in sleep stage (REM/SWS) as a % of total sleep time (TST), bout length. The primary metric for spatial navigational memory was %change in overnight completion time on a first-person-experience 3D maze task.

Results

Sleep macrostructure was normal during the normal night (TST:379.9±56.6 min; SWS:19.5±7.6%; REM:19.4±5.3%; mean±std). Stage-specific disruption of sleep was achieved using auditory tones during a) SWS-disruption condition (TST:388.9±47.4 mins; SWS:6.6±4.8%; REM:18.7±5.2%) and b) REM-disruption condition (TST:365.3±69.8 mins; SWS:17.1±7.7%; REM:12.1±6.6%). SWS-disruption reduced mean bout length of SWS as compared to no disruption (1.3±0.8 mins vs. 10.3±8.2 mins; p<0.01) and REM-disruption reduced mean bout length of REM as compared to no disruption (2.2±1.7 vs. 10.6±5.2 mins; p<0.01). When sleep was not disrupted, subjects achieved overnight improvements in performance (25.3±17%) which remained unchanged during REM-disruption (18.8±29.6%, p=0.5) and during SWS-disruption (38.8±24.4%; p=0.2). Morning psychomotor vigilance was also unaffected by condition.

Conclusion

Stage specific disruption of sleep can be achieved using graded auditory tones. While performance on a virtual 3D maze remain unchanged with stage specific sleep disruption, lower sample size may have limited our ability to detect the change. Activation patterns from functional neuroimaging that were acquired during the spatial navigation task may elucidate the interaction between stage-specific sleep disruption and performance.

Support

NIH R21AG059179

1150 Obstructive Sleep Apnea-dependent Racial/ethnic And Sex-specific Mechanisms Underlying Alzheimer’s Disease Risk: A Retrospective Cohort Analysis Of In-lab PSG Sleep Study Data

Introduction

We examined race and sex-specific biologic mechanisms of the relationship between obstructive sleep apnea (OSA) and incident AD.

Methods

Retrospective cohort analysis utilizing in-lab PSG sleep study data conducted among older adults between 2001 and 2005. OSA was defined using AHI4%. Participants had no history of cognitive decline or AD at baseline and included 663 (284 Non-Hispanic White (NHW), 207 Black/African-American (AA) and 172 Hispanic) OSA-patients matched on age, sex, race, BMI, 1:1 ratio to 663 (unexposed cohort I from sleep clinic) and 1:4 ratio to 2652 (unexposed cohort II from non-sleep clinics) non-OSA individuals. Incident AD was assessed annually from 2001-2013 with ICD-9-CM code 331.0. Adjusted cox proportional hazard regression models examined race and sex-specific biologic mechanisms including hypoxia, fragmentation and duration measures of OSA and AD risk.

Results

Of the 3,978 participants, 2,148 (54%) were women. Mean age at baseline was 72.6 (7.3) years. Over a mean follow-up time of 8.6 (1.4) years, 358 (9%) individuals (212 female) developed AD (119 NHW, 134 AAs, and 105 Hispanics). Relative to non-OSA individuals, OSA-patients had a higher risk of incident AD, with AAs and females showing stronger risk estimates (aHR: 2.24, 1.83, and 1.73, P <.001 for all, for AAs, Hispanics and NHW respectively; and aHR: 2.38, and 1.37, P <.001 for all, for female and male respectively). Measures of hypoxia, sleep fragmentation and sleep duration were associated with increase AD risk (P <.01 for all). Relative to NHW, AAs and Hispanics demonstrated up to 20% stronger effects/estimates on hypoxia and sleep duration measures. Relative to males, females demonstrated up to 25% stronger effects/estimates on sleep fragmentation measures, and 15% weaker effects/estimates on hypoxia measures (P <.01 for all).

Conclusion

Among OSA-patients, mechanisms related to hypoxia, sleep fragmentation and duration measures increase AD risk and may underlie race/ethnicity and sex disparities in AD.

Support

NIH/NIA/NHLBI (L30-AG064670, CIRAD P30AG059303 Pilot, T32HL129953, R01HL118624, R21AG049348, R21AG055002, R01AG056031, R01AG022374, R21AG059179, R01AG056682, R01AG056531, K07AG05268503, K23HL125939)

0144 Relationship Between Sleep EEG K-Complex Slow Wave Coupling and Next-Day Thalamic Activity During Psychomotor Vigilance Test in Obstructive Sleep Apnea

Introduction

There is large inter-individual variability in the relationship between obstructive sleep apnea (OSA) severity and lapses in vigilance as measured using psychomotor vigilance test (PVT). We have previously shown that overnight sleep EEG K-complex slow wave coupling (∆SWAK) exhibits a dose-responsive relationship with next-day lapses in vigilance in OSA on and off treatment. We hypothesized that a variable thalamic dysfunction in OSA explains difference in lapses in vigilance and alterations in ∆SWAK across individuals.

Methods

Five newly diagnosed severe OSA subjects (mean apnea-hypopnea index [AHI4%=57.1±22.8/hr.]) with excessive daytime sleepiness (Epworth Sleepiness Scale=11±3.4) underwent nocturnal polysomnography followed by PVT testing within a 3T SKYRA MRI scanner. The PVT task inside the scanner (PVT-fMRI) was adapted to match the gold standard PVT-192 device. Each fMRI scanning session consisted of 2 10-min PVT runs interleaved with 2 control conditions wherein the subject pressed the response button at random intervals absent of a visual stimulus. fMRI data was analyzed in 2-step procedure (individual time-series followed by group analysis) using Analysis of Functional Neuroimages (AFNI) software package. To estimate thalamic activity during PVT-fMRI, parameter estimates of the %change in blood-oxygen-level-dependent (BOLD) signal using the contrast PVT-Control were used as the primary metric. The region of interest was limited to the bilateral thalamus using the Eickhoff-Zilles macro labels from the MNI N27 template.

Results

In a preliminary test, PVT performance for the subjects inside the scanner was not significantly different from that outside the scanner (PVTLapsesfMRI=7.3±2.1 vs. PVTLapsesPVT192=6.4±3.6 mean±std; PVTLapses=reaction time > 500 ms.). Within subjects, a trend toward lower thalamic recruitment was observed during PVT-fMRI (-0.17±0.2%; p=0.1). Further, lower thalamic activity during PVT-fMRI also showed a trend to lower overnight ∆SWAK (mean -1.2±1.4) values (r = 0.61, p = 0.17).

Conclusion

In severe OSA subjects with excessive daytime sleepiness, we observed a trend to reduced thalamic activity during daytime PVT. Overnight EEG K-complex slow wave coupling showed a similar trend with next-day thalamic activity during PVT, however the small sample size may have limited our ability to detect this association with statistical significance.

Support

AASM Foundation 199-FP-18; NIH K24HL109156

Molting Site Fidelity in Workers of Formosan Subterranean Termites (Isoptera: Rhinotermitidae)

Spatial assessment of molting in workers of Coptotermes formosanus Shiraki was conducted in laboratory-reared colonies using extended foraging arenas. Workers at a premolt stage were found concentrated in the nest or in a planar arena near the nest. However, molting individuals were found exclusively in the central nest and they stayed inside or near the central nest for at least 36 h postmolting. The absence of premolt workers at foraging sites suggests that the workers have an affinity to the nest for molting and the second study on nest-fidelity evaluation suggested that the workers molt in the proximity of eggs. The molting site fidelity by workers in a colony ensures that speeding up the time for mortality induced by chitin synthesis inhibitor (CSI) baits will not result in an inhibitory cascade of dead termites around the bait stations. Thus, speeding up the elimination of a C. formosanus colony using CSI baits with the addition of molt-accelerating compounds will not lead to secondary repellency. Reasons for the molting-site fidelity amongst workers in a colony are discussed.

Is any particular aspect of perceived quality associated with patients tending to promote a dental practice to their friends and colleagues?

AIMS

To investigate the relationship between perceived quality and patients' tendencies to recommend a practice to friends and colleagues.

METHODS

Data from 64 practices using the Denplan Excel Patient Survey (DEPS) were analysed. The Net Promoter Score (NPS max score 100), developed by Reichheld, is reported to each practice using DEPS. It is claimed that the NPS measures the likelihood that patients will recommend the practice to friends and colleagues. A Patient Perception Index (PPI max score 100) is also reported to practices. The PPI is calculated from the responses to the ten core questions of DEPS on perceived quality. The 64 practices were placed into three groups for data analysis according to their NPS result: group one practices receiving an NPS of less than 80, group two practices receiving an NPS of 80-89 and group three practices receiving an NPS of greater than 89. These groups represented practices scoring statistically significantly (to 90% confidence) below the mean NPS (group one), practices close to the mean NPS (group two) and practices statistically significantly (to 90% confidence) above the mean NPS.

RESULTS

Group one practices scored a mean PPI of 73, group two scored a mean PPI of 76 and group three a mean PPI of 80. These differences in values of PPI between the groups are statistically significant (to 90% confidence). Of the ten constituent issues which contribute to PPI, the greatest difference in scoring between group one and group three was found to be around perceived value for money.

CONCLUSION

The probability of patients recommending a dental practice seems to rise in direct proportion to favourable perceptions of quality. A perception of 'ideal' value for money is the most highly correlated aspect with a high NPS.

The intravenous and oral pharmacokinetics of afoxolaner and milbemycin oxime when used as a combination chewable parasiticide for dogs

The pharmacokinetics of afoxolaner and milbemycin oxime (A3 and A4 forms) in dogs were evaluated following the oral administration of NexGard Spectra^® (Merial), a fixed combination chewable formulation of these two active pharmaceutical ingredients. Absorption of actives was rapid at levels that provide the minimum effective doses of 2.5 mg/kg and 0.5 mg/kg of afoxolaner and milbemycin oxime, respectively. The time to maximum afoxolaner plasma concentrations (t_max ) was 2-4 h. The milbemycin t_max was 1-2 h. The terminal plasma half-life (t_1/2 ) and the oral bioavailability were 14 ± 3 days and 88.3% for afoxolaner, 1.6 ± 0.4 days and 80.5% for milbemycin oxime A3 and 3.3 ± 1.4 days and 65.1% for milbemycin oxime A4. The volume of distribution (V_d ) and systemic clearance (Cls) were determined following an IV dose of afoxolaner or milbemycin oxime. The V_d was 2.6 ± 0.6, 2.7 ± 0.4 and 2.6 ± 0.6 L/kg for afoxolaner, milbemycin oxime A3 and milbemycin oxime A4, respectively. The Cls was 5.0 ± 1.2, 75 ± 22 and 41 ± 12 mL/h/kg for afoxolaner, milbemycin oxime A3 and milbemycin oxime A4, respectively. The pharmacokinetic profile for the combination of afoxolaner and milbemycin oxime supports the rapid onset and a sustained efficacy for afoxolaner against ectoparasites and the known endoparasitic activity of milbemycin oxime.

Long-term validity and reliability of a patient survey instrument designed for general dental practice

AIM

To consider the extent to which the validity and reliability of the Denplan Excel Patient Survey (DEPS) has been confirmed during its development and by its use in general dental practice and to explore methods by which any survey instrument used in general dental practice might be validated and tested for reliability.

METHODS

DEPS seeks to measure perceived practice performance on those issues considered to be of greatest importance to patients. Content validity was developed by a literature review and tested in a pilot study. Criterion validity was tested by comparing patient retention in a payment plan for practices achieving the highest DEPS scores with those attaining the lowest scores over a two year period (surveys completed between 2010 and 2012). Reliability was assessed using the test/re-test method for 23 practices with approximately a three year time interval between tests. Internal consistency was tested by comparing Net Promoter Scores (NPS - which is measured in DEPS) attained by practices with their Patient Perception Index (PPI) as measured by the ten core questions in DEPS.

RESULTS

Practices in the pilot study strongly endorsed the content validity of DEPS. The 12 practices with the highest scores in the DEPS slightly increased their number of patients registered in Denplan payment plans during a two year period. The 12 lowest scoring practices saw 7% of their patients de-register during the same period. The 23 practices selected for the test/re-test study averaged more than 250 responses for both the test and re-test phases. The magnitude and pattern of their results were similar in both phases, while, on average, a modest improvement in results was observed. Internal consistency was confirmed as NPS results in DEPS closely mapped PPI results. The higher the measurement of perceived quality (PPI) the more likely patients were to recommend the practice (NPS).

CONCLUSION

Both through its development and use over the last four years The DEPS has demonstrated good validity and reliability. The authors conclude that this level of validity and reliability is adequate for the clinical/general care audit purpose of DEPS and that it is therefore likely to reliably inform practices where further development are indicated. It is important and quite straightforward to both validate and check the reliability of patient surveys used in general dental practice so that dental teams can be confident in the instrument they are using.

Evaluation of an oral health scoring system by dentists in general dental practice

An Oral Health Index (OHX) has been designed to provide a numerical measure of the overall state of a patient's oral health by means of a series of simple clinical examinations. This has been amended to produce the Oral Health Score (OHS).

OBJECTIVE

To assess, by means of a questionnaire, the ease of use and understanding of the OHS by general dental practitioners.

METHODS

350 GDPs were asked to participate in the project, of whom 329 agreed. These dentists were given a lecture of 2 hours' duration on the OHS. The participating dentists were requested to use the OHS for a period of 1 year. At the end of this period, a questionnaire was delivered to them by post, with an explanatory letter and reply-paid envelope.

RESULTS

Completed, usable questionnaires were received from 239 GDPs, a 77% response rate. Ninety three percent of respondents considered the OHS instructions to be satisfactory. The respondents' views on the criteria on which the OHS component assessments are based indicated that over 90% of respondents agreed with the criteria for caries, adequacy of restorations, periodontal assessment, mucosal assessment and assessment of dentures. A majority of respondents agreed that the OHS provided a valid representation of oral health.

CONCLUSION

The results of the present study indicate that the OHS is considered to be an easy-to-use measure of a patient's oral health and that it provides a valid representation of a patient's oral health.

Surgery versus radiation therapy as single-modality treatment of tonsillar fossa carcinoma: the Roswell Park Cancer Institute experience (1971-1991)

OBJECTIVE

To compare the efficacy and treatment outcomes in patients with tonsillar fossa cancer using surgery or radiation as a single modality therapy.

METHODS

From 1971 to 1991 239 patients with oral pharyngeal cancer were treated at Roswell Park Cancer Institute. Of these patients 90 had tonsillar carcinoma. Seventy-six of these patients received either surgery (SA) (n = 56) or radiation therapy (RA) (n = 20) as single-modality therapy and are the subject of this review. All patients in the radiation arm of this review were surgical candidates who declined primary surgical therapy.

RESULTS

Sixty-three percent of the SA and 80% of the RA treatment groups presented with either stage III or stage IV disease (P < or = .05). Forty-seven percent of the SA group and 52% of the RA patients had clinically positive regional disease at initial presentation. There was a predictable pattern of nodal presentation, with level II the most frequently involved region. The rate of occult metastasis was 27% and was evenly distributed between T1 and T4 disease. The overall local control rate in the SA group was 75%, compared with 60% in the RA group (P value was not significant). The disease-specific survival (all stages) was 61% in the SA group and 37% in the RA group (P < or = .05). The disease-free survival for stage III and stage IV disease in the SA group was 47% and in the RA group 27% (P < or = .05). Survival measured against clinical response to radiation therapy, in complete responders (all stages) was 83%; by contrast there were no survivors past 24 months in the partial response group (P < or = .001).

CONCLUSION

The results from this study suggest that for early disease (stage I/II), surgery or radiation therapy as single-modality treatment is equally effective. For advanced disease radiation therapy is inferior to surgery as a single-modality treatment, as measured by ultimate survival and the local control of disease. There is, however, a subset of patients with advanced disease who respond to radiation therapy and whose survival is equivalent to our surgical cohort of patients.

Surgery as a single modality therapy for squamous cell carcinoma of the oral tongue

PURPOSE

The treatment of squamous cell cancer of the oral tongue remains a challenging clinical problem. The efficacy of primary treatment with surgery versus radiation therapy for early stage disease and an adequate treatment paradigm for the clinically negative neck continues to be the subject of clinical debate. We have reviewed our experience in the treatment of oral tongue cancer with surgery as a single definitive treatment modality.

PATIENTS AND METHODS

From 1971 to 1993, 79 patients with squamous cell carcinoma of the oral tongue were treated with surgery alone at Roswell Park Cancer Institute.

RESULTS

Clinically, 69% of the patients presented with stage I/II disease and 31% presented with stage III/IV. Survival by pathological stage I to IV was 89%, 95%, 76%, and 65%, respectively. Surgical therapy ranged from partial to total glossectomy. There were no patients with positive margins. Local recurrence was observed in 15% of patients with close margins (< 1 cm) and 9% of patients with adequate margins (> or = 1 cm). The incidence of pathological node positive (N+) disease was 6%, 36%, 50%, and 67% for T1, T2, T3, and T4 tumors, respectively. Twenty-five percent of patients undergoing elective neck dissection were pathological N+. All pathological confirmed nodal disease was at level I or II. Of the 43 patients with clinical N0 disease, 16% subsequently developed regional recurrence, all of which were surgically salvaged.

CONCLUSION

Locoregional control in patients with squamous cell carcinoma of the oral tongue can be achieved with primary surgical therapy. Adequate margins are crucial to local control. Salvage neck dissection may result in long-term survival for patients with regional relapse. Because of the high rate of occult disease (41%), we currently recommend prophylactic treatment of regional lymphatics for primary clinical disease of T2 or greater.