Does the definition of fluid responsiveness affect passive leg raising reliability? A methodological ancillary analysis from a multicentric study

BACKGROUND

Fluid challenge (FC) is often adopted as gold standard used to assess the reliability of passive leg raising (PLR) in predicting fluid responsiveness in the intensive care unit (ICU). This study aimed to address the impact of the different definitions and timings used to assess FC response on PLR reliability.

METHODS

Ancillary study from a data set of a multicentric study in 85 ICU patient with acute circulatory failure who received a FC (500 mL of crystalloids in 10 minutes) within the first 48h of ICU admission, preceded by PLR in 30 patients. FC response was assessed considering the changes in cardiac index (CI) and stroke volume index (SVI) using different thresholds and at different timepoints.

RESULTS

The definitions of fluid responsiveness by using CI or SVI with a 15% increase after 10 minutes were associated to the best performances of the PLR [AUC (95% CI) 0.94 (0.83-1.01); vs. AUC (95% CI) 0.95 (0.87-1.02)]. The sensitivity of the PLR by adopting the CI or the SVI as reference variable ranged from 54.1% to 67.6% and from 81.5% to 100.0%; the specificity from 65.9% to 78.0% and from 79.5% to 100.0%, respectively. Considering all the subgroups, the number of responders 10 minutes after FC administration was higher as compared to 15 and 30 minutes (140 vs. 120 and 125, respectively, p < 0.05).

CONCLUSIONS

The reliability of the PLR test to predict fluid responsiveness depends on the definition of FC adopted. The timing of FC outcome assessment affected the overall fluid responsiveness.

Neuromuscular Strategies in Stretch-Shortening Exercises with Increasing Drop Heights: The Role of Muscle Coactivation in Leg Stiffness and Power Propulsion

When applying drop jump exercises, knowing the magnitude of the stimulus is fundamental to stabilize the leg joints and to generate movements with the highest power. The effects of different drop heights on leg muscles coactivation, leg stiffness and power propulsion were investigated in fifteen sport science students. Drop jumps from heights of 20, 30, 40, 50, and 60 cm in a random order were performed on a force platform. During each drop jump, the ground reaction force, knee angle displacement, and synchronized surface-electromyography root-mean-square (sEMG_RMS) activity (vastus lateralis, VL; vastus medialis, VM; rectus femoris, RF; biceps femoris, BF; tibialis anterior, TA and lateral gastrocnemius, LG) were recorded. The coactivation in the pre-contact phase, between VL and BF, VM and BF as well as RF and BF, was dependent on the drop height (p < 0.01; effect size (ES) ranged from 0.45 to 0.90). Leg stiffness was dependent on the drop height (p < 0.001; ES = 0.27-0.28) and was modulated by the coactivation of VM-BF (p = 0.034) and RF-BF (p = 0.046) during the braking phase. Power propulsion was also dependent on the drop height (p < 0.001; ES = 0.34); however, it was primarily modulated by the coactivation of LG-TA during the braking phase (p = 0.002). The coactivation of thigh muscles explains leg stiffness adjustments at different drop heights. On the contrary, the coactivation of shank muscles is mostly responsible for the power propulsion.

Individualized Whole-Body Vibration: Neuromuscular, Biochemical, Muscle Damage and Inflammatory Acute Responses

Objective. We aimed to investigate the acute residual hormonal, biochemical, and neuromuscular responses to a single session of individualized whole-body vibration (WBV) while maintaining a half-squat position. Methods. Twenty male sport science students voluntarily participated in the present study and were randomly assigned to an individualized WBV group (with the acceleration load determined for each participant) or an isometric group (ISOM). A double-blind, controlled parallel study design with repeated measures was employed. Results. Testosterone and growth hormone increased significantly over time in the WBV group (P < .05 and P < .01, respectively; effect size [ES] ranged from 1.00 to 1.23), whereas cortisol increased over time in both groups (P < .01; ES ranged from 1.04 and 1.36). Interleukin-6 and creatine kinase increased significantly over time only in the WBV group (P < .05; ES = 1.07). The maximal voluntary contraction decreased significantly over time in the ISOM group (P = .019; ES = 0.42), whereas in the WBV group, the decrease did not reach a significant level (P = .05). The ratio of electromyographic activity and power decreased significantly over time in the WBV group (P < .01; ES ranged from 0.57 to 0.72). Conclusion. Individualized WBV increased serum hormonal concentrations, muscle damage, and inflammation to levels similar to those induced by resistance training and hypertrophy exercises.

Data on laser induced preferential crystal (re)orientation by picosecond laser ablation of zinc in air

Laser ablation of zinc is performed with a 6.7 ps pulsed laser source to investigate the ablation mechanism and resulting morphology of the irradiated surface. The data shows the changes in crater morphology, as well as chemical composition, for different number of pulses and laser fluence levels. We observed Laser Induced Preferential Crystal Orientation (LIPCO), as a result of ultra-short pulsed laser processing of Zn at a wavelength of 515 nm. Crystallographic data for other laser wavelengths, namely 343 and 1030 nm, as well as for Zn coated steel are also provided in support of this observation. Data presented in this article are related to the research article “Investigation of the ultrashort pulsed laser processing of zinc at 515 nm: morphology, crystallography and ablation threshold” [1].

Morphology of single picosecond pulse subsurface laser-induced modifications of sapphire and subsequent selective etching

The effect of 1030nm single picosecond pulsed laser-induced modification of the bulk of crystalline sapphire using a combined process of laser amorphization and selective wet chemical etching is studied. Pulse durations of more than 1 picosecond are not commonly used for this subsurface process. We examine the effect of 7 picosecond pulses on the morphology of the unetched, as well as etched, single pulse modifications, showing the variation of shape and size when varying the pulse energy and the depth of processing. In addition, a qualitative analysis of the material transformation after irradiation is provided as well as an analysis of cracking phenomena. Finally, a calculated laser intensity profile inside sapphire, using the Point Spread Function (PSF), is compared to the shape of the modifications. This comparison is employed to calculate the intensity threshold leading to amorphization, which equals 2.5⋅10¹⁴ ± 0.4⋅10¹⁴ W/cm².

[Use of TachoSil® in the entero-colic anastomoses: results of an observational study]

AIM

In the last decade while many comparative studies examined hemostatic topics, adhesives and sealants, few clinical trials were made. We are focusing our attention particularly on TachoSil®, and studying its efficacy on reducing the frequency of anastomotic leakage, thought to be one of the causes of prolonged periods of patients' hospitalization.

METHODS

We examined 188 patients who underwent colorectal and enteric surgery at our department between January 2010 and March 2013. The efficacy of fibrin glue was evaluated on a cohort of patients at risk of anastomosis leakage. To test the relationship between the application of TachoSil® and the type of complications, a multiple logistic regression model was implemented. Fisher exact Test was used to compare the relations between two groups. The Mann-Whitney test was used to account for the days necessary for the follow-up of the patients in the various units participating in the study.

RESULTS

From the logistic regression model we can infer that TachoSil® is a highly protective factor though not statistically significant (OR=0.78; P>0.05). The results obtained analyzing the average days of patients hospitalization show a statistically significant decrease of such parameter in patients under treatment, especially those who underwent transverse colon resection (P<0.001).

CONCLUSION

The results of this study show that TachoSil® is a highly protective factor, but its efficacy is not statistically significant due to the small number of patients treated. It is important to call the attention to the reduced number of the hospitalization needed for the patients under treatment.

No correlation between physicians administered elbow rating systems and patient's satisfaction

AIM

The aim of this study was to assess the functional outcome of patients who had undergone elbow arthroscopy, evaluating the correlation between three elbow scoring systems and the patients' subjective perception of satisfaction

METHODS

Fourteen patients who had undergone elbow arthroscopy were retrospective reviewed to evaluate the correlation between three elbow scoring systems and the patients' subjective perception of satisfaction at a mean follow-up time of 24 months (range 12-64 months). Two independent orthopedic surgeons evaluated all patients using three elbow scoring systems, a simple satisfaction question and a visual analogue scale.

RESULTS

The three scoring systems showed significant correlation with each other (P<0.05). There was no correlation between the results of the three scoring systems and patients' satisfaction: patients with the same level of satisfaction could perform differently at the scoring systems.

CONCLUSION

Although the three scoring systems used to evaluate the patients showed significant correlation with each other, they failed to correlate to patients' satisfaction. In reporting the results of arthroscopic elbow procedures, emphasis should be placed on individual variables, rather than on global elbow ratings. Further studies are needed to develop a single outcome evaluation system which is reliable, valid and sensitive to changes of clinical importance, which takes into account both patients' and physicians perspective, and which is short and practical to use.

[Physiology and in vivo measurements of nitric oxide in man]

Nitric oxide (NO) is a simple molecule, highly conserved across species with important effects on several physiological mechanisms. In the cardiovascular system, NO is tonically released by the endothelial cells in response to shear stress to maintain vascular tone. This effect is due to the relaxation of the vascular smooth muscle cells in the medium layer (tunica media) of the arterial wall. However, NO is also involved in the regulation of synaptic neurotransmission, platelet aggregation, inflammation, appetite, peristalsis, renal metabolism, respiratory function, lipid metabolism and glucose metabolism. Therefore, an abnormal production of NO (over- or under-production) has multi-systemic effects. Metabolic disorders like hypertension, obesity or dyslipidaemia are associated with a reduction of NO production. The mechanisms responsible for a decreased NO synthesis are partially known but oxidative stress, overproduction of endogenous inhibitors of the Nitric Oxide Synthase (NOS) such as asymmetric dimethylarginine (ADMA) and genetic factors may be implicated. The half-life of NO is extremely short in biological samples (t1/2 < or = 0.2 sec) and its in vivo measurement is very difficult. Therefore, indirect methods have been developed to measure the end products of NO metabolism in biological samples. Some of these methods have used stable isotopes to trace the metabolic fate of the precursor of NO (Arginine) and measure the appearance of stable isotopes in the end products [nitrate (NO3), nitrite (NO2), citrulline]. However, the existing methods are expensive, invasive and require complex analytical laboratory techniques.

Fatigue in adult coeliac disease

BACKGROUND

Fatigue is reported by many adults at the moment of diagnosis of coeliac disease and during follow-up.

AIM

To evaluate the prevalence, characteristics and associations of fatigue in adult coeliac disease patients.

METHODS

The investigated sample comprised adults from Campania, Italy. A total of 130 coeliac disease patients were consecutively recruited in both treated (59 on gluten-free diet) and untreated conditions (71 on normal diet). The control group was made up of 80 healthy controls. Coeliac disease patients and healthy controls underwent laboratory tests, a set of questionnaires for studying fatigue: visual analogue scale for fatigue, chronic fatigue syndrome questionnaire, fatigue severity scale and a modified version of the Zung self-rating depression scale.

RESULTS

Coeliac disease patients showed a significantly lower body mass index than controls (P = 0.0001), lower serum iron (P = 0.04). The entire cohort of coeliac disease patients reported greater modified version of the Zung self-rating depression scale score (P = 0.001), greater visual analogue scale for fatigue score (P = 0.0001) and greater chronic fatigue syndrome questionnaire score (P = 0.0001) compared with healthy controls. Coeliac disease patients on a gluten-free diet had a significantly higher modified version of the Zung self-rating depression scale score than coeliacs on a normal diet (P = 0.001). The prevalence of pathological modified version of the Zung self-rating depression scale score was 17% in all coeliac disease patients and 0% in healthy controls. A significant correlation was found between modified version of the Zung self-rating depression scale score and fatigue scale scores in coeliacs on a normal diet. Presence/absence of gastrointestinal symptoms did not show any significant correlation with modified version of the Zung self-rating depression scale score and fatigue scale scores. In coeliacs on a gluten-free diet, modified version of the Zung self-rating depression scale and fatigue scales scores did not significantly differ from coeliacs on a normal diet and were not related to dietetic compliance.

CONCLUSION

In coeliacs, fatigue is a common finding, which ameliorates with the gluten-free diet and is strictly correlated to depression although coeliacs on a gluten-free diet showed more frequent and more severe depression symptoms than coeliacs on a normal diet.

Distraction lengthening of the radius for radial longitudinal instability after distal radio-ulnar subluxation and excision of the radial head: a case report

The results of late surgery for symptomatic proximal migration of the radius after resection of the radial head for trauma are usually disappointing. Ulnar variance increases when the interosseous membrane is disrupted. Its integrity should be assessed to predict the results of further surgery. We describe a 29-year-old patient in whom distraction lengthening of the radius through an Ilizarov frame allowed him to regain pain-free function of the wrist and elbow after a complex Essex-Lopresti fracture dislocation and late symptoms of ulnar carpal impingement.

In utero partial liver resection in the rabbit model: a study on fetal tissue regeneration

In this study we developed a model of in vivo intrauterine partial liver resection in the fetal rabbit to analyze fetal liver regeneration. After intravenous anesthesia, 12 time-dated pregnant, California rabbits underwent a midline laparotomy and minimal hysterotomy at 24-25 days of gestational age. One fetus was exposed from each pregnant doe and the fetal liver was partially resected. Cesarean sections were performed 24, 48 and 72 h and 4 days after surgery. Three fetuses operated at 24 days of gestational age and 3 fetuses operated at 25 days were alive at retrieval. The fetuses and the sampled livers were weighed at retrieval and fetal liver weight showed a well-maintained value in all cases. Fetal livers were processed for the common histologic stains. Lymphocytes, polymorphonuclear leukocytes and phagocytes were counted from sections obtained in areas close to the edge of resection. Inflammatory cells showed a peculiar pattern of infiltration at different stages of repair, with a constantly increased number of phagocytes peaking 48 h after resection. Fetal liver seems to present a specific pattern of repair that differs from both the adult liver and other fetal tissues healing after injury.

[Immunohistochemical demonstration of neuropeptide Y in the normal human thymus and in thymoma]

The distribution of neuropeptide Y-like immunoreactivity in normal thymic parenchyma and in thymoma was evaluated in order to characterize the typical aspects of the thymic peptidergic pattern of innervation in normal and pathological conditions. The possible role of neuropeptide Y in neuromodulation of the immunological response is discussed.