Intubation in burns patients: a 5-year review of the Manchester regional burns centre experience.

Despite criteria to guide intubation from the American Burn Association (ABA), concerns remain regarding over-intubation of burns patients. The purpose of this study was to review appropriateness of intubation at a UK regional burns centre over a 5-year period. A 5-year retrospective review of adult patients admitted to the Manchester Burns Centre who underwent intubation at or prior to admission was performed. Intubations for non-burn indications or burns >40%TBSA were excluded. Patient demographic and burn characteristics data were extracted from medical records. Indications for intubation were compared to ABA and Denver criteria. 47 patients were identified, of which 40 met inclusion criteria for analysis. 72.5% and 95% of these patients met ABA or Denver criteria respectively. 30.8% of patients were extubated within 48 h. 50% patients extubated within 48 h had ≤1 indication for intubation or negative laryngoscopy. Complications related to intubation and ventilation were noted in 37.5% of patients, with ventilation associated pneumonia (VAP) being the most common occurring in 27.5%. 95% of patients fulfilled recognised criteria for intubation. However, 30% were extubated within 48 h, suggesting potentially avoidable intubation. This study suggests current intubation criteria may over-estimate risk of airway compromise and supports results from non-UK studies that a proportion of patients may be suitable for close observation rather than early intubation.

Non-identifiability of parameters for a class of shear-thinning rheological models, with implications for haematological fluid dynamics.

Choosing a suitable model and determining its associated parameters from fitting to experimental data is fundamental for many problems in biomechanics. Models of shear-thinning complex fluids, dating from the work of Bird, Carreau, Cross and Yasuda, have been applied in highly-cited computational studies of hemodynamics for several decades. In this manuscript we revisit these models, first to highlight a degree of uncertainty in the naming conventions in the literature, but more importantly to address the problem of inferring model parameters by fitting to rheology experiments. By refitting published data, and also by simulation, we find large, flat regions in likelihood surfaces that yield families of parameter sets which fit the data equally well. Despite having almost indistinguishable fits to experimental data these varying parameter sets can predict very different flow profiles, and as such these parameters cannot be used to draw conclusions about physical properties of the fluids, such as zero-shear viscosity or relaxation time of the fluid, or indeed flow behaviours. We verify that these features are not a consequence of the experimental data sets through simulations; by sampling points from the rheological models and adding a small amount of noise we create a synthetic data set which reveals that the problem of parameter identifiability is intrinsic to these models.

Influence of microvascular sutures on shear strain rate in realistic pulsatile flow.

Arterial thrombus formation is directly related to the mechanical shear experienced by platelets within flow. High shear strain rates (SSRs) and large shear gradients cause platelet activation, aggregation and production of thrombus. This study, for the first time, investigates the influence of pulsatile flow on local haemodynamics within sutured microarterial anastomoses. We measured physiological arterial waveform velocities experimentally using Doppler ultrasound velocimetry, and a representative example was applied to a realistic sutured microarterial geometry. Computational geometries were created using measurements taken from sutured chicken femoral arteries. Arterial SSRs were predicted using computational fluid dynamics (CFD) software, to indicate the potential for platelet activation, deposition and thrombus formation. Predictions of steady and sinusoidal inputs were compared to analyse whether the addition of physiological pulse characteristics affects local intravascular flow characteristics. Simulations were designed to evaluate flow in pristine and hand-sutured microarterial anastomoses, each with a steady-state and sinusoidal pulse component. The presence of sutures increased SSRmax in the anastomotic region by factors of 2.1 and 2.3 in steady-state and pulsatile flows respectively, when compared to a pristine vessel. SSR values seen in these simulations are analogous to the presence of moderate arterial stenosis. Steady-state simulations, driven by a constant inflow velocity equal to the peak systolic velocity (PSV) of the measured pulsatile flow, underestimated SSRs by ∼ 9% in pristine, and ∼ 19% in sutured vessels compared with a realistic pulse. Sinusoidal flows, with equivalent frequency and amplitude to a measured arterial waveform, represent a slight improvement on steady-state simulations, but still SSRs are underestimated by 1-2%. We recommend using a measured arterial waveform, of the form presented here, for simulating pulsatile flows in vessels of this nature. Under realistic pulsatile flow, shear gradients across microvascular sutures are high, of the order ∼ 7.9 × 106 m-1 s-1, which may also be associated with activation of platelets and formation of aggregates.

Assessment of the relationship between a written measure of empathy and an independently rated interview of Motivational Interviewing.

Motivational Interviewing (MI) is an evidence-based practice shown to be effective when working with people in treatment for substance use disorders. However, MI is a complex treatment modality optimized by training with feedback. Feedback, assessment and monitoring of treatment fidelity require measurement, which is typically done using audiotaped sessions. The gold standard for such measurement of MI skill has been an audiotaped interview, scored by a rater with a detailed structured instrument such as the Motivational Interviewing Treatment Integrity 2.0 (MITI 2.0) Coding System (Moyers, et al., 2005). The Helpful Responses Questionnaire (HRQ) (Miller, Hedrick, & Orlofsky, 1991) is a pen-and-paper test of empathy (a foundational MI skill) that does not require an audiotaped session. A randomized trial of three different regimens for training counselors in MI (live supervision using Teleconferencing, Tape-based supervision and Workshop only) (Smith et al., 2012) offered the opportunity to evaluate the performance of the HRQ as a measure of MI ability, compared to the several MITI 2.0 global scores and subscales. Participants were counselors (N=97) working at community-based substance use treatment programs, whose MI proficiency was measured at four time points: baseline (before an initial 2-day MI workshop), post-workshop, 8weeks post-workshop (i.e., post-supervision), and 20weeks post-workshop with both MITI 2.0 and HRQ. HRQ total scores correlated significantly with the Reflection to Question Ratio from the MITI 2.0 at post-workshop (r=0.33), week 8 (r=0.34), and week 20 (r=0.38), and with the Spirit (r=0.32) and Empathy (r=0.32) global scores at week 20. Correlations of HRQ with other MITI 2.0 subscales and time points after workshop were small and not significant. As predicted, HRQ scores differed between training conditions (X2(2)=7.88, p=0.02), with counselors assigned to live supervision achieving better HRQ scores than those in Workshop only. In summary, HRQ is a modestly accurate measure, mainly of the Reflection to Question Ratio, considered a core marker of MI skill. It is sensitive to training effects and may help identify counselors needing more intensive supervision. Given its ease of administration and scoring, HRQ may be a useful marker of MI skill during training efforts.

Is a fractured mandible an emergency?

We retrospectively audited the records of 708 patients who presented with the diagnosis of fractured mandible between January 2009 and July 2013 at the Queen Elizabeth Hospital, Birmingham. We assessed the different factors that may have altered their outcomes, and found that delay before definitive fixation caused no harm in either the short or the long term.

Prescription of antibiotics: does it alter the outcome for patients who have fractures of the angle of the mandible?

We retrospectively studied 708 consecutive patients at the Queen Elizabeth Hospital, Birmingham, to find out whether one of the four antibiotic protocols in use conferred any advantage (or disadvantage) on a patient who had a fractured angle of the mandible, and there was none. However, the time from initial injury until the time of the first dose of antibiotic was important. Clinically, if patients waited more than 72hours after the injury before the first dose of antibiotic was given, they had a three times higher rate of postoperative infection than patients who were given their first dose between 24 and 72hours after the injury. Morbidity was more than five times higher during the postoperative period if the patient had waited for three days before their first dose, compared with those given the first dose within eight hours of injury. The overall rate of malunion or non-union of the fracture was between five and 10 times higher if the patient had waited more than 72hours after injury compared with all the other groups. There was a considerable difference in cost between the intravenous and oral versions of the antibiotics used (Augmentin® and metronidazole) so, if it could be shown that the oral doses are as efficacious as intravenous doses, a great deal of money could be saved.

Microarterial anastomoses: A parameterised computational study examining the effect of suture position on intravascular blood flow.

This study investigates the extent to which individual aspects of suture placement influence local haemodynamics within microarterial anastomoses. An attempt to physically quantify flow characteristics of blood past microvascular sutures is made using computational fluid dynamics (CFD) software. Particular focus has been placed on increased shear strain rate (SSR), a known precipitant of intravascular platelet activation and thrombosis. Measurements were taken from micrographs of sutured anastomoses in chicken femoral vessels, with each assessed for bite width, suture angle and suture spacing. Computational geometries were then created to represent the anastomosis. Each suture characteristic was parameterised to allow independent or simultaneous adjustment. Flow rates were obtained from anonymised Doppler ultrasound scans of analogous vessels during preoperative assessment for autologous breast reconstruction. Vessel simulations were performed in 2.5mm ducts with blood as the working fluid. Vessel walls were non-compliant and a continuous Newtonian flow was applied, in accordance with current literature. Suture bite angle and spacing had significant effects on local haemodynamics, causing notably higher local SSRs, when simulated at extremes of surgical practice. A combined simulation, encompassing subtle changes of each suture parameter simultaneously i.e. representing optimum technique, created a more favourable SSR profile. As such, haemodynamic changes associated with optimum suture placement are unlikely to influence thrombus formation significantly. These findings support adherence to the basic principles of good microsurgical practice.

Self-Report After Randomly Assigned Supervision Does not Predict Ability to Practice Motivational Interviewing.

The objective of this study was to investigate the relation between self-report and objective assessment of motivational interviewing (MI) skills following training and supervision. After an MI workshop, 96 clinicians from 26 community programs (age 21-68, 65% female, 40.8% Black, 29.6% Caucasian, 24.5% Hispanic, 2.0% Asian, 3.1% other) were randomized to supervision (tele-conferencing or tape-based), or workshop only. At four time points, trainees completed a self-report of MI skill, using items from the MI understanding questionnaire (MIU), and were objectively assessed by raters using the Motivational Interviewing Treatment Integrity (MITI) system. Correlations were calculated between MIU and MITI scores. A generalized linear mixed model was tested on MIU scores, with MITI scores, supervision condition and time as independent variables. MIU scores increased from pre-workshop (mean = 4.74, SD = 1.79) to post-workshop (mean = 6.31, SD = 1.03) (t = 8.69, p < .0001). With supervision, scores continued to increase, from post-workshop to week 8 (mean = 7.07, SD = 0.91, t = 5.60, p < .0001) and from week 8 to week 20 (mean = 7.28, SD = 0.94, t = 2.43, p = .02). However, MIU scores did not significantly correlate with MITI scores, with or without supervision. Self-reported ability increased with supervision, but self-report was not an indicator of objectively measured skill. This suggests that training does not increase correspondence between self-report and objective assessment, so community treatment programs should not rely on clinician self-report to assess the need for ongoing training and supervision and it may be necessary to train clinicians to accurately assess their own skill.

Reconstructive outcomes of Mohs surgery compared with conventional excision: A 13-month prospective study.

Established in 2012, the Mersey Regional Centre for Mohs Surgery is the first UK Mohs service to be led by a Mohs trained Plastic & Reconstructive surgeon. We evaluate the resection requirements and reconstructive techniques of our patient group and compare their surgical outcome to that which would have been gained with conventional excision (CE) and reconstruction for the same lesions. 157 patients were analysed over 13 months. Had CE and reconstruction been used, 56% of patients would have received a more invasive or cosmetically less desirable reconstruction, and 24% of margins would remain incomplete. The outcome was unchanged in 20% of patients. A small but significant subgroup (9%) of patients would have lost fundamental structures e.g. orbital exenteration, or undergone reconstructions unnecessarily crossing aesthetic subunits. Whilst in its infancy, the Plastic & Reconstructive Mohs surgery service has provided a valuable contribution to the care given to patients in the Mersey and Cheshire Skin Cancer Network. Detailed referral criteria, thorough preoperative patient evaluation, and appreciation of the abilities and limits of CE have enabled the service to produce a demonstrable reconstructive benefit in 80% of patients when compared to non-Mohs resection and reconstruction.

The plastic & reconstructive Mohs surgery service.

Mohs Micrographic Surgery (MMS) is the current 'gold-standard' for excision of a number of cutaneous lesions and provides a valuable addition to a skin cancer service. The Mersey Regional Centre for Mohs Surgery is the first MMS service in the UK to be led by an MMS trained Plastic and Reconstructive surgeon, and this article describes an overview of the processes involved in establishing such a service.

"Old dogs" and new skills: how clinician characteristics relate to motivational interviewing skills before, during, and after training.

OBJECTIVE: The relationships between the occupational, educational, and verbal-cognitive characteristics of health care professionals and their motivational interviewing (MI) skills before, during, and after training were investigated. METHOD: Fifty-eight community-based addiction clinicians (M = 42.1 years, SD = 10.0; 66% Female) were assessed prior to enrolling in a 2-day MI training workshop and being randomized to one of three post-workshop supervision programs: live supervision via tele-conferencing (TCS), standard tape-based supervision (Tape), or workshop training alone. Audiotaped sessions with clients were rated for MI skillfulness with the Motivational Interviewing Treatment Integrity (MITI) coding system v 2.0 at pre-workshop and 1, 8, and 20 weeks post-workshop. Correlation coefficients and generalized linear models were used to test the relationships between clinician characteristics and MI skill at each assessment point. RESULTS: Baseline MI skill levels were the most robust predictors of pre- and post-supervision performances. Clinician characteristics were associated with MI Spirit and reflective listening skill throughout training and moderated the effect of post-workshop supervision method on MI skill. TCS, which provided immediate feedback during practice sessions, was most effective for increasing MI Spirit and reflective listening among clinicians with no graduate degree and stronger vocabulary performances. Tape supervision was more effective for increasing these skills among clinicians with a graduate degree. Further, TCS and Tape were most likely to enhance MI Spirit among clinicians with low average to average verbal and abstract reasoning performances. CONCLUSIONS: Clinician attributes influence the effectiveness of methods used to promote the acquisition of evidence-based practices among community-based practitioners.

Dermal substitutes do well on dura: comparison of split skin grafting +/- artificial dermis for reconstruction of full-thickness calvarial defects.

Large, full-thickness calvarial defects present a series of significant reconstructive challenges involving a range of techniques, including local and free flaps. Occasionally these conventional methods may not be possible due to technical, or patient, factors. Artificial dermis is already widely used in burns surgery and is increasing in oncological reconstruction. We believe that artificial dermis coupled with split-thickness skin grafting provides an excellent option for closure of these defects when other techniques are not appropriate.

Motivational interview improves treatment entry in homeless veterans.

Motivational Interviewing (MI) has successfully been used to facilitate entry and compliance in drug and alcohol treatment programs. Some questions have been raised as to the effectiveness of MI in severely distressed populations. This study aims to assess the effectiveness of MI in a population of homeless, unemployed, and substance dependent veterans who are being wait-listed for entry into a residential treatment program. Seventy-five veterans placed on a wait-list were randomized to receive a single MI or standard (Std) intake interview. Outcomes assessed were entry, and length of stay (LOS). Secondary outcomes assessed included program completion and rates of graduation. Readiness to change and self-efficacy were assessed before and after the interview. Significantly more participants entered the program in the MI group (95%) than in the Std group (71%). Although those in the MI group remained in the program longer, and had higher program completion and graduation rates, these differences were not statistically significant. No significant between-group or within-group differences were found in readiness or self-efficacy. This study demonstrates that a single, easily administered intervention can increase program entry. Also based on the study findings, further research into the question of whether MI can increase program retention, in a severely distressed population, is warranted.

Dermal substitutes do well on dura: comparison of split skin grafting+/-artificial dermis for reconstruction of full-thickness calvarial defects.

Large, full-thickness calvarial defects present a series of significant reconstructive challenges involving a range of techniques, including local and free flaps. Occasionally these conventional methods may not be possible due to technical, or patient, factors. Artificial dermis is already widely used in burns surgery and is increasing in oncological reconstruction. We believe that artificial dermis coupled with split-thickness skin grafting provides an excellent option for closure of these defects when other techniques are not appropriate.

Conservative observational management with selective delayed repair for large abdominal aortic aneurysms in high risk patients.

AIM: Abdominal aortic aneurysms (AAAs) larger than 5.5 cm should generally undergo elective repair. However, some of these patients have serious comorbid conditions, which greatly increase operative risk. This study evaluated the outcomes of nonoperative, observational management and selective delayed AAA repair in high-risk patients with large infrarenal and pararenal AAAs. METHODS: Among 226 patients with AAAs >5.5 cm, we selected 72 with AAAs 5.6-12.0 cm (mean 7.0 cm) for periods of nonoperative management because of their prohibitive surgical risks. Comorbid factors included a low ejection fraction of 15-34% (mean 22%) in 18 patients; FEV1 <50% (mean 38%) in 25; prior laparotomy in 10; and morbid obesity in 22. Follow-up was complete in the 72 patients for the 6-76 months (mean 23 months) that they were treated nonoperatively. Fifty-three patients ultimately underwent repair because of AAA enlargement or onset of symptoms after 6-72 months (mean 19 months) of observational treatment. RESULTS: Of the 72 selected patients, 54 (75%) are living and 18 (25%) are dead. Seven patients undergoing only nonoperative treatment presently survive after 28-76 months (mean 48 months). Of the 18 deaths, AAA rupture occurred in only 3 patients (4%) who had been observed for 12, 31, and 72 months before rupture. Nine other deaths (13%) occurred after 6-72 months from comorbidities unrelated to the patient's AAA. Six of the 53 patients undergoing delayed AAA repair died within 30 days of operation (11% mortality). The mortality for the 154 good risk AAA patients, who underwent prompt open or endovascular repair, was 2.2%. CONCLUSION: These data indicate that some patients with large AAAs and serious comorbidities are acceptably managed for long periods (6-76 months) by nonoperative means. Substantial delays of 12 to 76 months resulted in an AAA rupture rate of only 4%, while 13% of these patients (9 of 72) died of their comorbidities unrelated to AAA rupture or surgery and mortality in this group of patients, when operated on, was 11% (6 of 53). These findings support the selective use of nonoperative observational management in some patients with large AAAs and serious comorbidities.

Overt colon ischemia after endovascular aneurysm repair: the importance of microembolization as an etiology.

OBJECTIVE: The purpose of this study was to analyze the incidence, severity, and etiologic factors of the development of colon ischemia after endovascular aortoiliac aneurysm repair (EVAR). METHODS: During the last 9 years we performed 278 elective EVARs using a variety of grafts. To facilitate these repairs, one hypogastric artery (HA) was coil embolized in 109 patients and both HAs were coil embolized in 13 patients. The preprocedural status of the inferior mesenteric, hypogastric, and iliac arteries as well as anatomical characteristics of the abdominal aortic aneurysm were determined arteriographically and by computerized tomographic scans. Postoperative colon ischemia was documented by colonoscopy or operative findings. RESULTS: Colon ischemia occurred in eight patients (2.9%). Three patients with colon ischemia died and had evidence of widespread (cutaneous, renal, small bowel, and/or lower extremity) microembolization. One of these three had a colectomy and microscopic emboli were present. One other patient who required a colectomy also had pathologic evidence of colonic microembolization but survived. Four other patients with colon ischemia were treated conservatively and survived. In one patient, previous colectomy with interruption of mesenteric collaterals may have been a contributory cause of colon ischemia. Of the eight patients with colon ischemia, only one had unilateral HA occlusion, and none had bilateral HA occlusion. The other 121 patients with unilateral and bilateral HA occlusion had no evidence of colon ischemia. CONCLUSIONS: Colon ischemia occurs after EVAR with an incidence approximating that of open repair. Colon ischemia was unrelated to HA interruption. Embolization appears to be a major cause of colon ischemia, although inadequate mesenteric collateral circulation may also play an etiologic role. Mortality with colon ischemia accompanied by widespread embolization was high, whereas colon ischemia without it was often mild and amenable to nonoperative management.

Limited role for IVUS in the endovascular repair of aortoiliac aneurysms.

BACKGROUND: To determine the need for routine versus selective intraoperative IVUS during endovascular aortoiliac aneurysm (AIA) repair. METHODS: One-hundred and eighty-eight endovascular AIA repairs performed over a 5-year period were reviewed and included in the study. Surgeon-made aorto-uni-femoral grafts (n=78) and industry-made bifurcated or tube grafts (n=110) were used. In the initial 51 cases IVUS was routinely performed. In the latter 137 cases IVUS was used selectively. In this group graft deformities suspected on completion angiography or pullback pressure measurements were treated with balloon dilatation and stenting. IVUS was then performed only in the presence of a persistent pressure gradient or inconclusive angiographic findings. RESULTS: In the initial 51 cases IVUS revealed 20 lesions of which 8 were not initially detected angiographically and which required further treatment. In the latter 137 cases IVUS was necessary in only 1 case, and guided the treatment of an angiographically undetectable lesion. There have been no late episodes of graft compression, kinking, or thrombosis in the selective IVUS group. CONCLUSIONS: The use of pullback pressure measurements with a low threshold for angioplasty and stenting, especially in unsupported grafts, followed by the selective use of IVUS decreases the overall requirement for IVUS and its associated costs.