Early experience of an infectious and tropical diseases unit during the coronavirus disease (COVID-19) pandemic, Florence, Italy, February to March 2020.

We analysed the first 84 coronavirus disease (COVID-19) patients hospitalised in an infectious and tropical disease unit in Florence, Italy, over 30 days after the start of the COVID-19 outbreak in Italy. A 12% reduction in the rate of intensive care unit transfer was observed after the implementation of intensity care measures in the regular ward such as increasing the nurse/patient ratio, presence of critical care physicians and using high flow nasal cannulae oxygenation.

In-Line Filtration Reduces Postoperative Venous Peripheral Phlebitis Associated With Cannulation: A Randomized Clinical Trial.

BACKGROUND: Peripheral venous cannulation is an everyday practice of care for patients undergoing anesthesia and surgery. Particles infused with intravenous fluids (eg, plastic/glass/drugs particulate) contribute to the pathogenesis of peripheral phlebitis. The aim of this study is to demonstrate the efficacy of in-line filtration in reducing the incidence of postoperative phlebitis associated with peripheral short-term vascular access. METHODS: In this controlled trial, 268 surgical patients were randomly assigned to in-line filtration and standard care (NCT03193827). The incidence of phlebitis (defined as visual infusion phlebitis [VIP] score, ≥2) within 48 hours was compared between the 2 groups, as well as the onset and severity of phlebitis and the reasons for removal of the cannula. The lifespan of venous cannulae was compared for the in-line filter and no-filter groups through a Kaplan-Meier curve. RESULTS: The incidence of phlebitis within 48 hours postoperatively was 2.2% and 26.9% (difference, 25% [95% confidence interval {CI}, 12%-36%]; odds ratio, 0.05 [0.01-0.15]), respectively, for the in-line filter and no-filter groups (P < .001). From 24 to 96 hours postoperatively, patients in the no-filter group had higher VIP scores than those in in-line filter group (P < .001). Venous cannulae in the in-line filter group exhibited prolonged lifespan compared to those in the no-filter group (P = .01). In particular, 64 (47.8%) of cannulae in the in-line filter group and 56 (41.8%) of those in the no-filter group were still in place at 96 hours postoperatively. At the same time point, patients with a VIP score <3 were 100% in the in-line filter group and only 50% for the no-filter group. In-line filtration was a protective factor for postoperative phlebitis (hazard ratio, 0.05 [95% CI, 0.014-0.15]; P < .0001) and cannula removal (hazard ratio, 0.7 [95% CI, 0.52-0.96]; P = .02). CONCLUSIONS: In-line filtration has a protective effect for postoperative phlebitis and prolongs cannula lifespan during peripheral venous cannulation in surgical patients.

The New MIRUS System for Short-Term Sedation in Postsurgical ICU Patients.

OBJECTIVES: To evaluate the feasibility and safety of the MIRUS system (Pall International, Sarl, Fribourg, Switzerland) for sedation with sevoflurane for postsurgical ICU patients and to evaluate atmospheric pollution during sedation. DESIGN: Prospective interventional study. SETTING: Surgical ICU. February 2016 to December 2016. PATIENTS: Postsurgical patients requiring ICU admission, mechanical ventilation, and sedation. INTERVENTIONS: Sevoflurane was administered with the MIRUS system targeted to a Richmond Agitation Sedation Scale from -3 to -5 by adaptation of minimum alveolar concentration. MEASUREMENTS AND MAIN RESULTS: Data collected included Richmond Agitation Sedation Scale, minimum alveolar concentration, inspired and expired sevoflurane fraction, wake-up times, duration of sedation, sevoflurane consumption, respiratory and hemodynamic data, Simplified Acute Physiology Score II, Sepsis-related Organ Failure Assessment, and laboratory data and biomarkers of organ injury. Atmospheric pollution was monitored at different sites: before sevoflurane delivery (baseline) and during sedation with the probe 15 cm up to the MIRUS system (S1) and 15 cm from the filter-Reflector group (S2). Sixty-two patients were enrolled in the study. No technical failure occurred. Median Richmond Agitation Sedation Scale was -4.5 (interquartile range, -5 to -3.6) with sevoflurane delivered at a median minimum alveolar concentration of 0.45% (interquartile range, 0.4-0.53) yielding a mean inspiratory and expiratory concentrations of 0.79% (SD, 0.24) and 0.76% (SD, 0.18), respectively. Median awakening time was 4 minutes (2.2-5 min). Median duration of sevoflurane administration was 3.33 hours (2.33-5.75 hr), range 1-19 hours with a mean consumption of 7.89 mL/hr (SD, 2.99). Hemodynamics remained stable over the study period, and no laboratory data indicated liver or kidney injury or dysfunction. Median sevoflurane room air concentration was 0.10 parts per million (interquartile range, 0.07-0.15), 0.17 parts per million (interquartile range, 0.14-0.27), and 0.15 parts per million (interquartile range, 0.07-0.19) at baseline, S1, and S2, respectively. CONCLUSIONS: The MIRUS system is a promising and safe alternative for short-term sedation with sevoflurane of ICU patients. Atmospheric pollution is largely below the recommended thresholds (< 5 parts per million). Studies extended to more heterogeneous population of patients undergoing longer duration of sedation are needed to confirm these observations.

Vasodilator activity of hydrogen sulfide (H2S) in human mesenteric arteries.

The role of endogenous H2S has been highlighted as a gaseous transmitter. The vascular smooth muscle inhibitory effects of H2S have been characterized in isolated aorta and mesenteric arteries in rats and mice. Our study was aimed at investigating the vascular effects of H2S on human isolated mesenteric arteries and examining the underlying mechanisms involved. All experiments were performed on rings (4-8mm long) of human mesenteric arteries obtained from patients undergoing abdominal surgery. Ethical approval was obtained from the Ethics Committee of the University Hospital of the University of Florence (app. N. 2015/0024947). The effect of NaHS, an H2S donor, was determined using noradrenaline pre-contracted human isolated mesenteric rings. NaHS evoked a concentration-dependent relaxation (EC50 57µM). In contrast, homocysteine, an endogenous precursor of H2S, failed to affect human isolated mesenteric rings. Vasorelaxant response to NaHS was reduced by endothelium removal, application of the nitric oxide synthase inhibitor L-NAME and ODQ inhibitor of cyclic GMP. SQ 22536, an adenylate-cyclase inhibitor, failed to block NaHS-induced vasorelaxation. Inhibition of endogenous prostanoid production by indomethacin significantly reduced NaHS induced vasorelaxation. The role of potassium channels was also examined: blockers of the Ca2+-dependent potassium channel, charybdotoxin and apamin, failed to have any influence on the relaxant response to NaHS on this vascular tissue. In summary, H2S induced relaxation of isolated rings of human mesenteric arteries. Endothelium-dependent related mechanisms with the stimulation of ATP-sensitive potassium channels represents important cellular mechanisms for H2S effect on human mesenteric arteries.

Cardiac output: a central issue in patients with respiratory extracorporeal support.

The iLA-activve® Novalung is a new extracorporeal device specifically designed for lung support in patients with hypercapnic and/or hypoxemic respiratory failure. To date, only low-flow applications for decompensated hypercapnic chronic obstructive pulmonary disease have been reported in the literature. Here, we briefly report three cases of iLA-activve use in patients with hypercapnic-hypoxemic acute lung failure assisted with mid-flow (up to 2.4 L/min) and different single/double venous cannulation. The main findings of our small case series were: firstly, extracorporeal blood flows over 2.0 L/min across the membrane provided clinically satisfying decarboxylation and improved oxygenation; secondly, the ratio between blood flow through the membrane and the patient's cardiac output (CO) was a major determinant for the oxygen increase. The latter could, therefore, be a useful indicator for understanding performance in the complex and multifactorial evaluation of patients with extracorporeal veno-venous lung support.

The experience of setting up a resident-managed Acute Pain Service: a descriptive study.

BACKGROUND: The benefits of an Acute Pain Service (APS) for pain management have been widely reported, but its diffusion is still limited. There are two APS models: anesthesiologist-based and a nurse-based model. Here we describe the development of a different APS model managed by anesthesia residents, and we report the first year of activity in a tertiary Italian university hospital (Careggi University Hospital, Florence, IT). METHODS: Patients were included in the APS were those undergoing abdominal and urologic surgery causing moderate or severe postsurgical pain. The service was provided for patients, beginning upon their exit from the operating room, for 4, 12, 24 and 48 h for iv, and up to 72 h for epidural therapy. Vital signs, static/dynamic VAS, presence of nausea/vomiting, sedation level, and Bromage scale in case of epidural catheter, were monitored. RESULTS: From September 2013 to April 2015, a total of 1054 patients who underwent major surgery were included in the APS: 542 from abdominal surgery and 512 from urological surgery. PCA and epidural analgesia were more adopted in general surgical patients than in urology (48% vs 36% and 15% vs 2%, respectively; P < 0.0001). Patients who underwent to abdominal surgery had a significantly higher self-administration of morphine (30.3 vs 22.7 mg; P = 0.0315). Elastomeric pump was the analgesic of choice in half of the urologic patients compared to a quarter of the general surgical patients (P < .0001). Among the different surgical techniques, epidural analgesia was used more in open (16.5%) than in videolaparoscopic (1.9%) and robotic technique (1.1%), whereas PCA was predominant in videolaparoscopic (46.5%) and robotic technique (55.5%) than in open technique (31.4%). CONCLUSIONS: The creation of APS, managed by anesthesia residents, may represent an alternative between specialist-based and nurse-based models.

Advanced accident research system based on a medical and engineering data in the metropolitan area of Florence.

BACKGROUND: In the metropolitan area of Florence, 62% of major traumas involve powered two wheeler rider and pillion passengers, 10% cyclists, and 7% pedestrians. The urban and extra-urban areas are the most dangerous for the vulnerable road user. In-depth investigations are needed for assessing detailed information on road accidents. This type of study has been very limited in time frame in Italy, and completely absent in the Tuscan region.Consequently a study called "In-depth Study of road Accident in FlorencE" (In-SAFE) has been initiated. METHODS: A network between the Department of Mechanics and Industrial Technologies (University of Florence) and the Intensive Care Unit of the Emergency Department (Careggi Teaching Hospital, Florence) was created with the aim of collecting information about the road accidents. The data collected includes: on-scene data, data coming from examination of the vehicles, kinematics and dynamic crash data, injuries, treatment, and injury mechanisms. Each injury is codified thorough the AIS score, localized by a three-dimensional human body model based on computer tomography slices, and the main scores are calculated. We then associate each injury with its cause and crash technical parameters. Finally, all the information is collected in the In-SAFE database. RESULTS: Patient mean age at the time of the accident was 34.6 years, and 80% were males. The ISS mean is 24.2 (SD 8.7) and the NISS mean is 33.6 (SD 10.5). The main road accident configurations are the "car-to-PTW" (25%) and "pedestrian run over" (17,9%). For the former, the main collision configuration is "head-on crash" (57%). Cyclists and PTW riders-and-pillions-passengers suffer serious injuries (AIS3+) mainly to the head and the thorax. The head (56.4%) and the lower extremities (12.7%) are the most frequently injured pedestrian body regions. CONCLUSIONS: The aim of the project is to create an in-depth road accident study with special focus on the correlation between technical parameters and injuries. An in-depth investigation team was setup and is currently active in the metropolitan area of Florence.Twenty-eight serious road accidents involving twenty-nine ICU patients are studied. PTW users, cyclist and pedestrians are the most frequently involved in metropolitan accidents.

Early intra-intensive care unit psychological intervention promotes recovery from post traumatic stress disorders, anxiety and depression symptoms in critically ill patients.

INTRODUCTION: Critically ill patients who require intensive care unit (ICU) treatment may experience psychological distress with increasing development of psychological disorders and related morbidity. Our aim was to determine whether intra-ICU clinical psychologist interventions decrease the prevalence of anxiety, depression and posttraumatic stress disorder (PTSD) after 12 months from ICU discharge. METHODS: Our observational study included critical patients admitted before clinical psychologist intervention (control group) and patients who were involved in a clinical psychologist program (intervention group). The Hospital Anxiety and Depression Scale (HADS) and Impact of Event Scale-Revised questionnaires were used to assess the level of posttraumatic stress, anxiety and depression symptoms. RESULTS: The control and intervention groups showed similar demographic and clinical characteristics. Patients in the intervention group showed lower rates of anxiety (8.9% vs. 17.4%) and depression (6.5% vs. 12.8%) than the control group on the basis of HADS scores, even if the differences were not statistically significant. High risk for PTSD was significantly lower in patients receiving early clinical psychologist support than in the control group (21.1% vs. 57%; P < 0.0001). The percentage of patients who needed psychiatric medications at 12 months was significantly higher in the control group than in the patient group (41.7% vs. 8.1%; P < 0.0001). CONCLUSIONS: Our results suggest that that early intra-ICU clinical psychologist intervention may help critically ill trauma patients recover from this stressful experience.

Ventilatory and ECMO treatment of H1N1-induced severe respiratory failure: results of an Italian referral ECMO center.

BACKGROUND: Since the first outbreak of a respiratory illness caused by H1N1 virus in Mexico, several reports have described the need of intensive care or extracorporeal membrane oxygenation (ECMO) assistance in young and often healthy patients. Here we describe our experience in H1N1-induced ARDS using both ventilation strategy and ECMO assistance. METHODS: Following Italian Ministry of Health instructions, an Emergency Service was established at the Careggi Teaching Hospital (Florence, Italy) for the novel pandemic influenza. From Sept 09 to Jan 10, all patients admitted to our Intensive Care Unit (ICU) of the Emergency Department with ARDS due to H1N1 infection were studied. All ECMO treatments were veno-venous. H1N1 infection was confirmed by PCR assayed on pharyngeal swab, subglottic aspiration and bronchoalveolar lavage. Lung pathology was evaluated daily by lung ultrasound (LUS) examination. RESULTS: A total of 12 patients were studied: 7 underwent ECMO treatment, and 5 responded to protective mechanical ventilation. Two patients had co-infection by Legionella Pneumophila. One woman was pregnant. In our series, PCR from bronchoalveolar lavage had a 100% sensitivity compared to 75% from pharyngeal swab samples. The routine use of LUS limited the number of chest X-ray examinations and decreased transportation to radiology for CT-scan, increasing patient safety and avoiding the transitory disconnection from ventilator. No major complications occurred during ECMO treatments. In three cases, bleeding from vascular access sites due to heparin infusion required blood transfusions. Overall mortality rate was 8.3%. CONCLUSIONS: In our experience, early ECMO assistance resulted safe and feasible, considering the life threatening condition, in H1N1-induced ARDS. Lung ultrasound is an effective mean for daily assessment of ARDS patients.

Implantation of 3951 long-term central venous catheters: performances, risk analysis, and patient comfort after ultrasound-guidance introduction.

BACKGROUND: Despite evidence demonstrating improved safety with ultrasound-guided placement of central venous catheters (CVC) in comparison with the use of anatomical landmarks, ultrasound guidance is still not routinely used by all physicians when obtaining central venous access. METHODS: We report data pertaining to the placement of long-term CVCs in a 7-year period before and after ultrasound guidance was introduced. We included 3951 procedures (total of 1,642,402 catheter days) in our study: 1584 using the anatomical landmark method (landmark group, January 2000 to May 2003), and 2367 with ultrasound guidance (ultrasound group, June 2003 to May 2007). All procedures were performed by the same team of intensivists. Comparison criteria included procedural data, complications, patient's comfort, and perceptions. Variables were analyzed with Student's t test and χ(2) test. Multivariate analysis was performed according to the Cox proportional hazards regression model. RESULTS: Using ultrasound guidance, we noted a significant reduction in procedure time in both port (mean difference 4.9 ± 0.4 minutes, confidence interval [CI] 4.1 to 5.7) and tunneled catheter (mean difference 2.4 ± 0.8 minutes, CI 0.9 to 3.8) placement. The landmark method was associated with an increased risk of overall perioperative complications (4.5, CI 3.6 to 5.6). Among disease entities, acute leukemia patients had a significantly higher risk of CVC-related infections (2.6, CI 2.1 to 3.8). On the basis of questionnaires submitted to patients from both groups, ultrasound guidance was associated with improved patient comfort and satisfaction. CONCLUSIONS: Ultrasound guidance reduces complications and improves patient comfort. Further studies are needed to define whether acute leukemia patients should be considered a separate category with regard to the higher incidence of infections.

The use of point-of-care bedside lung ultrasound significantly reduces the number of radiographs and computed tomography scans in critically ill patients.

BACKGROUND: Chest radiography has been reported to have low diagnostic accuracy in critically ill intensive care unit (ICU) patients, and chest computed tomography (CT) scans require patients to be transported out of the ICU, putting them at risk of adverse events. In this study we assessed the efficacy of routine bedside lung ultrasound (LUS) in the evaluation of pleural effusions (PE) in the ICU. METHODS: Three hundred seventy-six patients admitted to the ICU for major trauma (46.3%), medical pathology (41.5%), and postsurgical complications (12.2%) (May 2008 to April 2009) were included in this study. Patients were placed into either the control group (group C) or the study group (group S), on the basis of the introduction of routine LUS performed by a single group of intensivists in 1 tertiary care ICU. To reduce provider bias, the physicians conducting the LUS were not aware of the study. Collected data included patient demographics, clinical course, and number of chest radiographs and CT scans performed. As a secondary goal, we assessed the reliability of Balik's formula in PE estimation. RESULTS: No significant differences were found between the 2 groups with regard to their demographics and ICU clinical course. Group S had a significant reduction in the total number of chest radiographs obtained (-26%; P < 0.001) and CT scans (-47%; P < 0.001) in comparison with the comparison group C. A 6-month follow-up analysis of the ICU LUS protocol revealed a time-dependent decrease in the number of radiological examinations requested for patients with PE. Lastly, PE volume estimation using the LUS and Balik's formula correlates well with the effective volume drained (r = 0.65; P < 0.0001). CONCLUSIONS: Routine use of LUS in the ICU setting can be associated with a reduction of the number of chest radiographs and CT scans performed.

Early tracheostomy in intensive care unit: a retrospective study of 506 cases of video-guided Ciaglia Blue Rhino tracheostomies.

BACKGROUND: Percutaneous dilatational tracheostomy (PDT) is a common procedure in critically ill patients, but the correct timing is still controversial. This study was designed to establish whether an early timing in video-guided Ciaglia Blue Rhino PDT affects the duration of mechanical ventilation (MV) and the length of stay (LOS) in intensive care unit (ICU). Secondary clinical outcomes were the overall hospitalization duration and the mortality rate. METHODS: A retrospective, single-center study of 2,210 patients admitted to the ICU of the Emergency Department of the Careggi Teaching Hospital (Florence, Italy) between 2002 and 2007. Among the 506 patients who underwent PDT, 256 and 250 patients were retrospectively assigned to the early tracheostomy (ET) or late tracheostomy (LT) group according to whether the procedure was performed before (ET) or after (LT) 3 days of MV (median time of procedure execution). RESULTS: The two groups of patients showed comparable demographic and clinical characteristics. The video-guided PDT procedures were performed without major complications in all cases. The average timing of tracheostomy in the ET group was 1.9 +/- 0.9 days, whereas in LT group resulted 6.8 +/- 3.8 days (mean +/- SD). Total hospital LOS and mortality rate were not different between the two groups. However, the duration of MV days and of ICU LOS group were significantly shorter in the ET group (13.3 +/- 9.6 and 16.9 +/- 13.0 days, respectively; p = 0.0001) than in the LT group (16.7 +/- 8.3 days and 20.8 +/- 9.2 days, respectively; p < 0.0001). Stratified analysis by the three major ICU admission diagnosis confirmed that both traumatized and nontraumatized (medical and postsurgical) ET patients had a shorter MV duration and ICU LOS as compared with LT patients. CONCLUSIONS: Video-guided Ciaglia Blue Rhino PDT is safe and easy to perform in ICU. No difference in overall hospital LOS, incidence of pneumonia, and mortality rate between the ET and LT groups was found. However, in both traumatized and nontraumatized patients, shortened duration of ICU LOS and MV in the ET group (

Vacuum-assisted closure device enhances recovery of critically ill patients following emergency surgical procedures.

INTRODUCTION: Critically ill surgical patients frequently develop intra-abdominal hypertension (IAH) leading to abdominal compartment syndrome (ACS) with subsequent high mortality. We compared two temporary abdominal closure systems (Bogota bag and vacuum-assisted closure (VAC) device) in intra-abdominal pressure (IAP) control. METHODS: This prospective study with a historical control included 66 patients admitted to a medical and surgical intensive care unit (ICU) of a tertiary care referral center (Careggi Hospital, Florence, Italy) from January 2006 to April 2009. The control group included patients consecutively treated with the Bogota bag (Jan 2006-Oct 2007), whereas the prospective group was comprised of patients treated with a VAC. All patients underwent abdominal decompressive surgery. Groups were compared based upon their IAP, SOFA score, serial arterial lactates, the duration of having their abdomen open, the need for mechanical ventilation (MV) along with length of ICU and hospital stay and mortality. Data were collected from the time of abdominal decompression until the end of pressure monitoring. RESULTS: The Bogota and VAC groups were similar with regards to demography, admission diagnosis, severity of illness, and IAH grading. The VAC system was more effective in controlling IAP (P < 0.01) and normalizing serum lactates (P < 0.001) as compared to the Bogota bag during the first 24 hours after surgical decompression. There was no significant difference between the SOFA scores. When compared to the Bogota, the VAC group had a faster abdominal closure time (4.4 vs 6.6 days, P = 0.025), shorter duration of MV (7.1 vs 9.9 days, P = 0.039), decreased ICU length of stay (LOS) (13.3 vs 19.2 days, P = 0.024) and hospital LOS (28.5 vs 34.9 days; P = 0.019). Mortality rate did not differ significantly between the two groups. CONCLUSIONS: Patients with abdominal compartment syndrome who were treated with VAC decompression had a faster abdominal closure rate and earlier discharge from the ICU as compared to similar patients treated with the Bogota bag.

Bedside diagnostic laparoscopy to diagnose intraabdominal pathology in the intensive care unit.

INTRODUCTION: Delayed diagnosis of intraabdominal pathology in the intensive care unit (ICU) increases rates of morbidity and mortality. Intraabdominal pathologies are usually identified through presenting symptoms, clinical signs, and laboratory and radiological results; however, these could also delay diagnosis because of inconclusive laboratory tests or imaging results, or the inability to safely transfer a patient to the radiology room. In the current study we evaluated the safety and accuracy of bedside diagnostic laparoscopy to confirm the presence of intraabdominal pathology in an ICU setting. METHODS: This retrospective study, carried out between January 2006 and June 2008, evaluated the diagnostic accuracy of bedside diagnostic laparoscopy performed on patients with a suspicion of ongoing intraabdominal pathology. Clinical indications for bedside diagnostic laparoscopy were: ultrasonography (US) images of gallbladder distension or wall thickening of more than 3 to 4 mm, with or without pericholecystic fluid; elevation of laboratory tests (bilirubin, transaminases, myoglobin, lactate dehydrogenase, creatine phosphokinase, gamma-glutamyltransferase); high level of lactate/metabolic acidosis; CT images inconclusive for intraabdominal pathology; or inability to perform a CT scan. Patients did not undergo bedside diagnostic laparoscopy if they presented clear indications for open surgery, coagulopathy, abdominal wall infection or high intraabdominal pressure. RESULTS: Thirty-two patients underwent bedside diagnostic laparoscopy (Visiport Plus, Autosuture, US), 14 of whom had been admitted to the ICU for major trauma, 12 for sepsis of unknown origin and 6 for complications after cardiac surgery. The procedure was performed on an average of eight days after ICU admission (95% confidence interval = 5 to 15 days) and mean procedure duration was 40 minutes. None of the procedures resulted in complications. Bedside diagnostic laparoscopy was diagnostic for intraabdominal pathology in 15 patients, who subsequently underwent surgery, except in two cases of diffuse gut hypoperfusion. Diagnosis of cholecystitis was obtained in seven cases: two were treated with laparotomic cholecystectomy and five with percutaneous gallbladder drainage positioning. CONCLUSIONS: Bedside diagnostic laparoscopy represents a safe and accurate technique for diagnosing intraabdominal pathology in an ICU setting and should be taken into consideration when patient transfer to radiology or the operating room is considered unsafe, or when routine radiological examinations are not conclusive enough to reach a definite diagnosis.

The Valsalva manoeuvre versus tourniquet for venipuncture.

BACKGROUND: During ultrasound-guided cannulation, venous filling is required for venipuncture. Tourniquet with an elastic tube at the axilla is the most common method to induce venous stasis for cannulation of the deep veins of the arm. Although effective, this method might be associated with short- and long-term complications. Valsalva manoeuvre has been used to produce venous filling in other extrathoracic veins. The aim of this observational study is to demonstrate the effect of Valsalva manoeuvre in respect of the elastic tourniquet on venous distention during echography-guided cannulation of the deep veins of the arm. METHOD: Sixty-nine patients scheduled for cannulation of basilic or brachial vein were prospectively observed. Vein diameters were recorded at rest and after 10 s of Valsalva or tourniquet placement. RESULTS: The mean difference between basilic vein diameters during tourniquet and Valsalva manoeuvre was 0.006 mm (95% confidence interval = -inf, 0.09) with a standard deviation of 0.5 mm (95% confidence interval = 0.5, 0.7; p > 0.01). The mean difference between brachial vein diameters during tourniquet and Valsalva manoeuvre was 0.04 mm (95% confidence interval = -0.23, 0.15) with a standard deviation of 0.8 mm (95% confidence interval = 0.7, 0.9; p > 0.01). DISCUSSION: This increase in cross-sectional basilic and brachial vein diameters was not different to that obtained with the elastic tube tourniquet.

Hydrogen sulfide inhibits human platelet aggregation.

Gaseous mediators such as nitric oxide (NO) play a major regulatory role in the cardiovascular system homeostasis, including platelet aggregation. Here, we investigated whether hydrogen sulfide (H(2)S), a newly recognized endogenous mediator, can affects aggregation of human platelets, using sodium hydrogen sulfide (NaHS) as H(2)S-donor. NaHS inhibited platelet aggregation induced by ADP, collagen, epinephrine, arachidonic acid, thromboxane mimetic, U46619, and thrombin. H(2)S effect was not dependent by cAMP/cGMP generation, NO production or potassium-channels opening. NaHS concentrations (up to 10 mM) did not exert toxic effects on platelet viability. The possible protective role of endogenous H(2)S in cardiovascular system is discussed.