A pilot study of alternative substrates in the critically Ill subject using a ketogenic feed.

Bioenergetic failure caused by impaired utilisation of glucose and fatty acids contributes to organ dysfunction across multiple tissues in critical illness. Ketone bodies may form an alternative substrate source, but the feasibility and safety of inducing a ketogenic state in physiologically unstable patients is not known. Twenty-nine mechanically ventilated adults with multi-organ failure managed on intensive care units were randomised (Ketogenic n = 14, Control n = 15) into a two-centre pilot open-label trial of ketogenic versus standard enteral feeding. The primary endpoints were assessment of feasibility and safety, recruitment and retention rates and achievement of ketosis and glucose control. Ketogenic feeding was feasible, safe, well tolerated and resulted in ketosis in all patients in the intervention group, with a refusal rate of 4.1% and 82.8% retention. Patients who received ketogenic feeding had fewer hypoglycaemic events (0.0% vs. 1.6%), required less exogenous international units of insulin (0 (Interquartile range 0-16) vs.78 (Interquartile range 0-412) but had slightly more daily episodes of diarrhoea (53.5% vs. 42.9%) over the trial period. Ketogenic feeding was feasible and may be an intervention for addressing bioenergetic failure in critically ill patients. Clinical Trials.gov registration: NCT04101071.

Comparison of Cystatin C and Creatinine in the Assessment of Measured Kidney Function during Critical Illness.

BACKGROUND: Incomplete recovery of kidney function is an important adverse outcome in survivors of critical illness. However, unlike eGFR creatinine, eGFR cystatin C is not confounded by muscle loss and may improve identification of persistent kidney dysfunction. METHODS: To assess kidney function during prolonged critical illness, we enrolled 38 mechanically ventilated patients with an expected length of stay of >72 hours near admission to intensive care unit (ICU) in a single academic medical center. We assessed sequential kidney function using creatinine, cystatin C, and iohexol clearance measurements. The primary outcome was difference between eGFR creatinine and eGFR cystatin C at ICU discharge using Bayesian regression modeling. We simultaneously measured muscle mass by ultrasound of the rectus femoris to assess the confounding effect on serum creatinine generation. RESULTS: Longer length of ICU stay was associated with greater difference between eGFR creatinine and eGFR cystatin C at a predicted rate of 2 ml/min per 1.73 m 2 per day (95% confidence interval [CI], 1 to 2). By ICU discharge, the posterior mean difference between creatinine and cystatin C eGFR was 33 ml/min per 1.73 m 2 (95% credible interval [CrI], 24 to 42). In 27 patients with iohexol clearance measured close to ICU discharge, eGFR creatinine was on average two-fold greater than the iohexol gold standard, and posterior mean difference was 59 ml/min per 1.73 m 2 (95% CrI, 49 to 69). The posterior mean for eGFR cystatin C suggested a 22 ml/min per 1.73 m 2 (95% CrI, 13 to 31) overestimation of measured GFR. Each day in ICU resulted in a predicted 2% (95% CI, 1% to 3%) decrease in muscle area. Change in creatinine-to-cystatin C ratio showed good longitudinal, repeated measures correlation with muscle loss, R =0.61 (95% CI, 0.50 to 0.72). CONCLUSIONS: eGFR creatinine systematically overestimated kidney function after prolonged critical illness. Cystatin C better estimated true kidney function because it seemed unaffected by the muscle loss from prolonged critical illness. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Skeletal Muscle Wasting and Renal Dysfunction After Critical Illness Trauma - Outcomes Study (KRATOS), NCT03736005 .

The learning preferences of aspiring orthopaedic surgeons in the UK.

BACKGROUND/AIMS: The workload of orthopaedic trainees is rapidly increasing at the expense of training. Trainees are expected to assimilate large quantities of information efficiently. This prospective cohort study explores the learning styles, resource preferences and educational needs of aspiring orthopaedic trainees. METHOD: A 21-item questionnaire was distributed to delegates of an orthopaedic teaching series. Data were obtained pertaining to demographics, visual, aural, read/write and kinaesthetic learning styles, study materials used and teaching exposure. RESULTS: Participants had a strong preference for visual (48.0%) and kinaesthetic (43.0%) learning modalities. Most participants prepared for written exams using online question banks (85.9%), clinical exams using question banks (37.5%) and discussion with colleagues (27.3%), and surgical procedures intraoperatively (43.8%). Only 12.4% of participants felt the teaching they received was consistently adapted to their visual, aural, read/write or kinaesthetic learning preference. CONCLUSIONS: The surgical landscape is rapidly changing. It is vital that trainers take into consideration how budding orthopaedic surgeons learn and make the relevant accommodations, to ensure optimal learning.

Acute versus delayed total hip arthroplasty after acetabular fracture fixation: a systematic review and meta-analysis.

BACKGROUND: Post-traumatic osteoarthritis (PTOA) is a disabling complication of open reduction and internal fixation (ORIF) for acetabular fractures. There is a trend towards acute total hip arthroplasty (THA), 'fix-and-replace', in patients considered to have a poor prognosis and likelihood of PTOA. Controversy remains between early fix-and-replace, versus delayed THA as required after initial ORIF. This systematic review included studies comparing functional and clinical outcomes between acute versus delayed THA after displaced acetabular fractures. METHODS: Comprehensive searches following the PRISMA guideline were performed on six databases for articles in English published anytime up to 29 March 2021. Two authors screened articles and discrepancies were resolved by consensus. Patient demographics, fracture classification, functional and clinical outcomes were compiled and analysed. RESULTS: The search yielded 2770 unique studies, of which five retrospective studies were identified with a total of 255 patients. Of them, 138 (54.1%) were treated with acute and 117 (45.9%) treated with delayed THA. Delayed THA group represented a younger cohort compared to the acute group (mean age, 64.3 vs 73.3). The mean follow-up time for the acute and delayed group was 23 and 50 months, respectively. There was no difference in functional outcomes between the two study groups. Complication and mortality rates were comparable. Delayed THA had a higher revision rate compared to the acute group (17.1 vs 4.3%; p = 0.002). CONCLUSION: Fix-and-replace had functional outcomes and complication rates similar to ORIF and delayed THA, but lower revision rates. Although the quality of studies was mixed, sufficient equipoise now exists to justify randomised studies in this area. PROSPERO registration: CRD42021235730.

Outcomes after primary intramedullary nail fixation of open tibial and femoral fractures in low resource settings.

INTRODUCTION: Open fractures are unique in the urgency they impart to the injury and the therapeutic challenge they pose. Non-union and infection are among the major concerns. Open tibial and femoral shaft fractures are among the commonest orthopaedic urgencies. Primary intramedullary (IM) nailing requires a skillset and knowledge of the principles of open fracture management and also a well-equipped operating room with the necessary implants and instruments. In a low resource setting, one or more of these prerequisites may not be met, and the outcome may thus be affected similarly. The objective of this study was to study these outcomes. METHODS: We prospectively studied primary IM nailing of open 1, 2 and 3A tibial and femoral fractures done in our hospital, in a simple non-modular operating room without an image intensifier. RESULTS: There were 106 fractures in 104 patients: 93 tibial and 13 femoral. The mean time from injury to surgical debridement was 19.6 h. Mean duration of antibiotics therapy was 4.3 days, and the mean duration of hospital stay was 4.1 days. All patients were followed up to union. Mean time to radiographic union was 6.1 months for the tibia and 5.7 months for the femur. Non-union was seen in 4 tibial and 1 femoral fractures. There were 3 superficial infections but no deep infection. CONCLUSION: The outcomes were comparable to, and in some cases better than, those found in existing literature. We conclude that primary IM nailing in open long bone fractures can be performed in austere environments with good success, in expert hands if the principles are adhered to.

Pentraxin 3 in Circulating Microvesicles: a Potential Biomarker for Acute Heart Failure After Cardiac Surgery with Cardiopulmonary Bypass.

The aim of this study was to investigate whether pentraxin 3 (PTX3) in microvesicles (MVs) can be a valuable biomarker for the prediction of acute heart failure (AHF) after cardiac surgery with cardiopulmonary bypass (CPB). One hundred and twenty-four patients undergoing cardiac surgery with CPB were included and analyzed (29 with AHF and 95 without AHF). The concentrations of PTX3 in MVs isolated from plasma were measured by ELISA kits before, 12 h, and 3 days after surgery. Patients' demographics, medical history, surgical data, and laboratory results were collected. The levels of PTX3 in MVs were significantly elevated during perioperative surgery, which was increased more in the AHF group. The concentrations of PTX3 in MVs at postoperative 12 h were independent risk factors for AHF with the area under the ROC curve of 0.920. The concentration of PTX3 in MVs may be a novel biomarker for prediction of AHF after cardiac surgery.

Size Distribution of Microparticles: A New Parameter to Predict Acute Lung Injury After Cardiac Surgery With Cardiopulmonary Bypass.

Background: Acute lung injury (ALI) is a common complication after cardiac surgery with cardiopulmonary bypass (CPB). No precise way, however, is currently available to predict its occurrence. We and others have demonstrated that microparticles (MPs) can induce ALI and were increased in patients with ALI. However, whether MPs can be used to predict ALI after cardiac surgery with CPB remains unknown. Methods: In this prospective study, 103 patients undergoing cardiac surgery with CPB and 53 healthy subjects were enrolled. MPs were isolated from the plasma before, 12 h after, and 3 d after surgery. The size distributions of MPs were measured by the LitesizerTM 500 Particle Analyzer. The patients were divided into two subgroups (ALI and non-ALI) according to the diagnosis of ALI. Descriptive and correlational analyzes were conducted between the size distribution of MPs and clinical data. Results: Compared to the non-ALI group, the size at peak and interquartile range (IQR) of MPs in patients with ALI were smaller, but the peak intensity of MPs is higher. Multivariate logistic regression analysis indicated that the size at peak of MPs at postoperative 12 h was an independent risk factor for ALI. The area under the curve (AUC) of peak diameter at postoperative 12 h was 0.803. The best cutoff value of peak diameter to diagnose ALI was 223.05 nm with a sensitivity of 88.0% and a negative predictive value of 94.5%. The AUC of IQR at postoperative 12 h was 0.717. The best cutoff value of IQR to diagnose ALI was 132.65 nm with a sensitivity of 88.0% and a negative predictive value of 92.5%. Combining these two parameters, the sensitivity reached 92% and the negative predictive value was 96%. Conclusions: Our findings suggested that the size distribution of MPs could be a novel biomarker to predict and exclude ALI after cardiac surgery with CPB.

The impact of virtual medical student surgical conferences.

BACKGROUND: In recent years, the number of people pursuing a surgical career in the UK has decreased. The COVID-19 pandemic has led to the cancellation of surgical placements for medical students and has affected surgical education. This study evaluates the perceptions and impact of a 1-day virtual surgical conference for medical students considering pursuing a surgical career. METHODS: All delegates of the 2021 Barts and The London International Surgical Conference were invited to participate in two online surveys pre- and post-conference. Data were collected and analysed to evaluate delegates' reasons for attending the conference, and attitudes towards virtual conferences and a surgical career before and after the conference. RESULTS: Out of 132 participants, 106 (80.3%) completed both the pre- and post-conference surveys. Clinical students showed a statistically significant difference in interest in pursuing a surgical career after the conference than before (P=0.03), unlike pre-clinical students (P=0.12). Post-conference, 43 (40.6%) preferred a virtual to a face-to-face conference, which was a slight increase from 40 (37.7%) pre-conference, while 73 (68.9%) and 80 (75.5%) participants favoured virtual talks and presentations respectively. In contrast, only 12 (11.3%) and 21 (19.8%) students preferred workshops and networking virtually. Furthermore, delegates liked the global accessibility and environmentally-friendly nature of virtual conferences but found they can be less engaging and be disrupted by a poor internet connection. CONCLUSIONS: Virtual surgical conferences have many benefits and can help encourage medical students towards a surgical career. They could help bridge the surgical educational gap in medical school during these unprecedented times. Virtual conferences, which have a broader and more inclusive reach, could be an important complement to conventional conferences after the pandemic.

Low Tidal Volume Reduces Lung Inflammation Induced by Liquid Ventilation in Piglets With Severe Lung Injury.

Total liquid ventilation (TLV) is an alternative treatment for severe lung injury. High tidal volume is usually required for TLV to maintain adequate CO2 clearance. However, high tidal volume may cause alveolar barotrauma. We aim to investigate the effect of low tidal volume on pulmonary inflammation in piglets with lung injury and under TLV. After the establishment of acute lung injury model by infusing lipopolysaccharide, 12 piglets were randomly divided into two groups, TLV with high tidal volume (25 mL/kg) or with low tidal volume (6 mL/kg) for 240 min, respectively. Extracorporeal CO2 removal was applied in low tidal volume group to improve CO2 clearance and in high tidal volume group as sham control. Gas exchange and hemodynamic status were monitored every 30 min during TLV. At the end of the study, pulmonary mRNA expression and plasmatic concentration of interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured by collecting lung tissue and blood samples from piglets. Arterial blood pressure, PaO2 , and PaCO2 showed no remarkable difference between groups during the observation period. Compared with high tidal volume strategy, low tidal volume resulted in 76% reduction of minute volume and over 80% reduction in peak inspiratory pressure during TLV. In addition, low tidal volume significantly diminished pulmonary mRNA expression and plasmatic level of IL-6 and IL-8. We conclude that during TLV, low tidal volume reduces lung inflammation in piglets with acute lung injury without compromising gas exchange.

[Effects of Haikun Shenxi on expression of platelet-derived growth factor-B and mRNA in renal tissue of rats with adriamycin nephropathy].

OBJECTIVE: To investigate the effects of Haikun Shenxi on the expression of platelet-derived growth factor-BB (PDGF-BB) and mRNA in renal tissue of rats with adriamycin nephropathy. METHOD: Rat model was established by unilateral nephrectomy and injecting adriamycin intraperitoneally. The adriamycin-induced nephrotic rats were randomly divided into 6 groups: normal group, sham operation group, model group, lotensin treatment group, Haikun Shenxi low and high dose treatment groups (0.77, 0.08 mg x kg(-1). Ten weeks later, the 24 hour urine protein and blood biochemistry examinations and renal pathologic changes were observed, and the expression of PDGF-BB and mRNA was measured using immunohistochemical method. RESULT: Compared with model group, proteinuria and the levels of serum creatinine (Scr) , urea nitrogen (BUN) were decreased obviously in both Haikun Shenxi low and high dose groups. The expression of PDGF-BB and mRNA was mostly presented in cytoplasm of renal tubular epithelial cells and mesangial area, and it could be reduced significantly after treatment (P < 0. 05). CONCLUSION: The level of PDGF-BB and mRNA is high in renal tissue of adriamycin-induced nephrotic rats. This progress could be effectively inhibited by Haikun Shenxi and the mechanism may be that it can control the excessive expression of PDGF-BB and mRNA.