The effect of simulation in improving students’ performance in laparoscopic surgery: a meta-analysis

Background

There is increasing interest in using simulators for laparoscopic surgery training, and simulators have rapidly become an integral part of surgical education.

Methods

We searched MEDLINE, EMBASE, Cochrane Library, and Google Scholar for randomized controlled studies that compared the use of different types of simulators. The inclusion criteria were peer-reviewed published randomized clinical trials that compared simulators versus standard apprenticeship surgical training of surgical trainees with little or no prior laparoscopic experience. Of the 551 relevant studies found, 17 trials fulfilled all inclusion criteria. The effect sizes (ES) with 95?% confidence intervals [CI] were calculated for multiple psychometric skill outcome measures.

Results

Data were combined by means of both fixed- and random-effects models. Meta-analytic combined effect size estimates showed that novice students who trained on simulators were superior in their performance and skill scores (d?=?1.98, 95?% CI: 1.20–2.77; P?<?0.01), were more careful in handling various body tissue (d?=?1.08, 95?% CI: 0.36–1.80; P?<?0.01), and had a higher accuracy score in conducting laparoscopic tasks (d?=?1.38, 95?% CI: 0.30–2.47; P?<?0.05).

Conclusion

Simulators have been shown to provide better laparoscopic surgery skills training for trainees than the traditional standard apprenticeship approach to skill development. Surgical residency programs are highly encouraged to adopt the use of simulators in teaching laparoscopic surgery skills to novice students.     

Procalcitonin and interleukin 6 for predicting blood culture positivity in sepsis

Background

Procalcitonin and interleukin 6 (IL-6) are well-known predictors of blood culture positivity in patients with sepsis. However, the association of procalcitonin and IL-6 with blood culture positivity was assessed separately in previous studies. This study aims to examine and compare the performance of procalcitonin and IL-6, measured concomitantly, in predicting blood culture positivity in patients with sepsis.

Methods

Forty adult patients with sepsis were enrolled in the study. Blood cultures were drawn before the institution of antibiotic therapy. The area under the curve (AUC) of the receiver operating characteristic curve was estimated to assess the performance of procalcitonin and IL-6 in predicting blood culture positivity.

Results

Positive blood cultures were detected in 10 patients (25%). The AUC of procalcitonin and IL-6 was 0.85 and 0.61, respectively. The combined performance of procalcitonin and IL-6 was similar to that of procalcitonin alone, AUC of 0.85. On univariate analysis, only procalcitonin and IL-6 were associated with blood culture positivity. Multivariate logistic regression analysis showed that only procalcitonin was associated with blood culture positivity (odds ratio, 12.15 [1.29-114.0] for levels above the median compared with levels below the median). Using procalcitonin cut points of 1.35 and 2.14 (nanogram per milliliter) enabled 100% and 90% identification of positive blood cultures and reduced the need of blood cultures by 47.5% and 57.5%, respectively.

Conclusions

Compared with IL-6, procalcitonin better predicts blood culture positivity in patients with sepsis. Using a predefined procalcitonin cut points will predict most positive blood cultures and reduce the need of blood cultures in almost half of patients with sepsis.     

Brain natriuretic peptide at discharge as a predictor of 6-month mortality in acute decompensated heart failure

Background

Brain natriuretic peptide (BNP) is well established in detecting acute decompensation of heart failure (ADHF). The role of BNP at discharge in predicting mortality is less established. Accumulating evidence suggests that inflammatory cytokines play an important role in the development of heart failure. We aimed to examine the contribution of BNP, interleukin 6, and procalcitonin to mortality in ADHF.

Methods

A cohort of 33 patients with ADHF was identified between March 2009 and June 2010 at Rambam Health Care Campus, Haifa, Israel. The cohort was followed up for all-cause mortality during 6 months after hospital discharge. Cox proportional hazard model was used to assess the association between BNP, interleukin-6 and procalcitonin and all-cause mortality.

Results

As compared to BNP at admission, BNP at discharge was more predictive for all-cause mortality. The area under the curve for BNP at admission and discharge was 0.810 (P = .004) and 0.864 (P = .001) respectively. Eleven patients (33.3%) patients who died during the follow-up period had higher BNP levels, median 2031.4 (IQR, 1173.4-2707.2), than those who survived; median 692.5 (IQR, 309.9-1159.9), (P = .001). On multivariate analysis, BNP remained an independent predictor for 6 month all-cause mortality HR 9.58 (95% CI, 2.0-45.89) for levels above the median compared to lower levels, (P = .005). Albumin, procalcitonin and interleukin 6 were not associated with all-cause mortality.

Conclusions

BNP at discharge is an independent predictor for all-cause mortality in patients with ADHF. Compared with BNP at admission, BNP at discharge has slightly higher predictive accuracy with regard to 6-month all-cause mortality.     

Pulmonary Hypertension,Right Ventricular Function,and Clinical Outcome in Acute Decompensated Heart Failure

BackgroundPulmonary hypertension (PH) and right ventricular (RV) dysfunction have been associated with adverse outcome in patients with chronic heart failure. However, data are lacking in the setting of acute decompensated heart failure (ADHF). We sought to determine prognostic significance of PH in patients with ADHF and its interaction with RV function.MethodsWe studied 326 patients with ADHF. Pulmonary artery systolic pressure (PASP) and RV function were determined with the use of Doppler echocardiography, with PH defined as PASP >50 mm Hg. The primary end point was all-cause mortality during 1-year follow-up.ResultsPH was present in 139 patients (42.6%) and RV dysfunction in 83 (25.5%). The majority of patients (70%) with RV dysfunction had PH. Compared with patients with normal RV function and without PH, the adjusted hazard ratio (HR) for mortality was 2.41 (95% confidence interval [CI] 1.44–4.03; P = .001) in patients with both RV dysfunction and PH. Patients with normal RV function and PH had an intermediate risk (adjusted HR 1.78, 95% CI 1.11–2.86; P = .016). Notably, patients with RV dysfunction without PH were not at increased risk for 1-year mortality (HR 1.04, 95% CI 0.43–2.41; P = .94). PH and RV function data resulted in a net reclassification improvement of 22.25% (95% CI 7.2%–37.8%; P = .004).ConclusionsPH and RV function provide incremental prognostic information in ADHF. The combination of PH and RV dysfunction is particularly ominous. Thus, the estimation of PASP may be warranted in the standard assessment of ADHF.     

Evaluation of (99m)Tc-ciprofloxacin scintigraphy in a rabbit model of Staphylococcus aureus prosthetic joint infection.

Ciprofloxacin, a quinolone antibiotic drug, binds to DNA topoisomerase IV and DNA gyrase of various bacteria. Thus ciprofloxacin labeled with (99m)Tc could potentially act as a specific marker allowing discrimination between infection and sterile inflammation. We evaluated these properties on a rabbit model of prosthetic joint infection previously validated. We compared the images obtained in 2 groups of animals: rabbits with infected (G1; n = 6) and uninfected (G2; n = 7) prosthesis. METHODS: Partial right-knee arthroplasty was performed on 13 New Zealand White female rabbits, with a tibial silicone-elastomer implant fitting into the intramedullary canal of the tibia. After the surgical wound was closed, 10(7) cfu of a clinical strain of methicillin-susceptible Staphylococcus aureus were injected into the joint in G1 rabbits. G2 rabbits were injected with sterile saline. No antibiotic therapy was given to the animals. (99m)Tc-ciprofloxacin planar imaging was performed on days 5, 12, and 19 after surgery, and after 3 mo in 1 uninfected rabbit. Images were obtained 1, 4, and 24 h after injection (147 +/- 13 MBq). RESULTS: In G1, increased right knee (99m)Tc-ciprofloxacin uptake was observed in 3 of 5 rabbits on day 5, and in all cases on days 12 and 19. Killing of the animals revealed purulent arthritis, osteitis, and tibial myelitis. In G2, significant right-knee uptake was found on days 12 and 19 in 5 of 6 rabbits, and after 3 mo in 1; all sets of images were negative in 1 animal. Bacteriologic studies after the animals were killed were negative in G2. Mean right/left knee uptake ratios on day 19 (4-h images) were 1.8 +/- 0.4 in G1 versus 1.4 +/- 0.3 in G2 (not significant). Late images did not discriminate between infected and uninfected arthroplasty. CONCLUSION: Results of (99m)Tc-ciprofloxacin imaging in rabbits with infected/uninfected knee prosthesis suggest good sensitivity but lack of specificity for the detection of S. aureus infection.     

Aflatoxin and immunity in layer hens.

A study was conducted on the impact of aflatoxin in the feed on the prophylactic immunization of layer hens against Newcastle disease, infectious bronchitis, infectious bursal disease and fowl cholera. Four-hundred-and-eighty 18-week-old white leghorn chickens were used. Different groups of hens were vaccinated, as per commercial recommendations, with a commercial inactivated triple vaccine against Newcastle disease, infectious bronchitis, and infectious bursal disease. A killed polyvalent bacterin was used for fowl cholera. Aflatoxin was fed for 22 weeks at a daily dose of 200 parts/10(9)/hen. Aflatoxin significantly reduced antibody titres, resulted in a decrease of egg weight, a decrease in egg production and an increase of mortality rate in challenged hens. Aflatoxin was detected in eggs at levels far above the permissible concentration.     

Differential binding of chromium(VI) and chromium(III) complexes to salmon sperm nuclei and nuclear DNA and isolated calf thymus DNA

The binding of CrCl₃.6H₂O, Cr(NO₃)₃.9H₂O, [Cr(L-His)₂] (NO₃)₃.H₂O,[Cr(L-Cys)(L-His)].3.5H₂O, [Cr(L-His)(D-Pen)].H₂O, Na[Cr(L-Cys)₂].2H₂O,K₂[Cr(GS)₂].3H₂O, Na₂-CrO₄.4H₂O, and Na₂Cr₂O₇.2H₂O to salmonsperm nuclei and nuclear DNA was determined. The Cr(III)-aminoacid complexes and Cr(VI) exhibited significantly lower Cr-nucleiand Cr-DNA binding levels relative to the inorganic complexesCrCl₃.6H₂O and Cr(NO₃)₃.9H₂O. The binding of CrCl₃.6H₂O, Cr(NO₃)₃.9H₂Oand Na₂Cr₂O₇.2H₂O to salmon sperm nuclei and nuclear DNA inthe presence of rat lung cytosol was determined under the sameconditions. For those complexes studied in both buffer and cytosol,the Cr-DNA binding levels for Cr(III) complexes were higherin buffer than in cytosol, while a relatively higher bindinglevel was observed for Cr(VI) in cytosol than in buffer. Slightlylower nuclear protein levels were present in Cr(VI) incubationsthan in Cr(III) incubations with nuclei both in the presenceand the absence of cytosol. The relative binding of CrCl₃.6H₂O,Cr(NO₃)₃.9H₂O, [Cr(L-His)₂](NO)₃.H₂O, [Cr(L-Cys) (L-His)].3.5H₂O,[Cr(L-His)(D-Pen)].H₂O, Na[Cr(L-Cys)₂].2H₂O and Na₂CrO₄.4H₂Oto isolated calf thymus DNA in buffer was also determined. Positivelycharged, labile inorganic Cr(III) complexes, CrCl₃.6H₂O andCr(NO₃)₃.9H₂O, exhibited higher binding to DNA than [Cr(L-His)(D-Pen)].H₂O, and no binding to DNA was observed with Cr(VI)and the other neutral, positively and negatively charged, inertCr(III)-amino acid complexes. Although labile aquo chromium(III)complexesare quite reactive with DNA, the reactivity of chromium(III),formed upon intracellular reduction of carcinogenic chromium(VI),toward DNA will be diminished by complexation with cellularproteins, peptides and amino acids.     

Midline lumbar ganglion/synovial cyst mimicking an epidural tumor: case report and review of pathogenesis

A case of a midline lumbar extradural ganglion/synovial cyst causing lumbar canal stenosis and mimicking an epidural tumor is presented. The lesion was demonstrated by a magnetic resonance imaging study, and relief of symptoms was achieved with decompressive laminectomy and total removal of the mass. The pathogenesis of lumbar ganglion/synovial cyst is reviewed.     

Thermal enhancement of radiosensitivity in normal and ataxia telangiectasia human cells

Normal human and ataxia telangiectasia (AT) fibroblasts were tested for enhancement of radiosensitivity by hyperthermia. In normal fibroblasts, thermal enhancement of radiosensitivity occurred at 42.0 degrees C and 45.0 degrees C and was greatest for simultaneous treatments of heat and radiation. This thermal enhancement decreased, as an incubation time at 37.0 degrees C was introduced either between heat and X-ray, or X-ray and heat, treatments. AT cells were more radiosensitive (D0 = 0.67 Gy) than normal cells (D0 = 1.4 Gy). Heating at 42.0 degrees or 45.0 degrees C resulted in enhanced radiosensitivity, which was equal for heating before, during or after irradiation. These data show that normal human fibroblasts can recover from heat and radiation treatments, while AT fibroblasts lack this ability.     

Experiences with head injuries in a regional neurosurgical unit.

A review of all patients with major head injuries transferred to a regional neurosurgical unit for the years 1975 and 1976 has been carried out for comparison with the total number of patients with head injury admitted to district general hospitals of the region. Fifty-four per cent of patients admitted to the neurosurgical unit have resumed their old occupation and 20 per cent died. The significance of these figures is discussed, particularly in the light of the need for a more comprehensive policy for treating head injuries within the United Kingdom.