Lorenzo Tofani

Accuracy of invasive arterial pressure monitoring in cardiovascular patients: an observational study

IntroductionCritically ill patients and patients undergoing high-risk and major surgery, are instrumented with intra-arterial catheters and invasive blood pressure is considered the “gold standard” for arterial pressure monitoring. Nonetheless, artifacts due to inappropriate dynamic response of the fluid-filled monitoring systems may lead to clinically relevant differences between actual and displayed pressure values. We sought to analyze the incidence and causes of resonance/underdamping phenomena in patients undergoing major vascular and cardiac surgery.MethodsArterial pressures were measured invasively and, according to the fast-flush Gardner’s test, each patient was attributed to one of two groups depending on the presence (R-group) or absence (NR-group) of resonance/underdamping. Invasive pressure values were then compared with the non-invasive ones.ResultsA total of 11,610 pulses and 1,200 non-invasive blood pressure measurements were analyzed in 300 patients. Ninety-two out of 300 (30.7%) underdamping/resonance arterial signals were found. In these cases (R-group) systolic invasive blood pressure (IBP) average overestimation of non-invasive blood pressure (NIBP) was 28.5 (15.9) mmHg (P <0.0001) while in the NR-group the overestimation was 4.1(5.3) mmHg (P <0.0001). The mean IBP-NIBP difference in diastolic pressure in the R-group was −2.2 (10.6) mmHg and, in the NR-group −1.1 (5.8) mmHg. The mean arterial pressure difference was 7.4 (11.2) mmHg in the R-group and 2.3 (6.4) mmHg in the NR-group. A multivariate logistic regression identified five parameters independently associated with underdamping/resonance: polydistrectual arteriopathy (P =0.0023; OR = 2.82), history of arterial hypertension (P =0.0214; OR = 2.09), chronic obstructive pulmonary disease (P =0.198; OR = 2.61), arterial catheter diameter (20 vs. 18 gauge) (P <0.0001; OR = 0.35) and sedation (P =0.0131; OR = 0.5). The ROC curve for the maximal pressure–time ratio, showed an optimum selected cut-off point of 1.67 mmHg/msec with a specificity of 97% (95% CI: 95.13 to 99.47%) and a sensitivity of 77% (95% CI: 67.25 to 85.28%) and an area under the ROC curve by extended trapezoidal rule of 0.88.ConclusionPhysicians should be aware of the possibility that IBP can be inaccurate in a consistent number of patients due to underdamping/resonance phenomena. NIBP measurement may help to confirm/exclude the presence of this artifact avoiding inappropriate treatments.

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.

Multisite Near Infrared Spectroscopy During Cardiopulmonary Bypass in Pediatric Patients

Multisite near infrared spectroscopy (NIRS) monitoring during pediatric cardiopulmonary bypass (CPB) has not been extensively validated. Although it might be rational to explore regional tissue saturation at different body sites (namely brain, kidney, upper body, lower body), conflicting results are currently provided by experience in children. The aim of our study was to evaluate absolute values of multisite NIRS saturation during CPB in a cohort of infants undergoing pediatric cardiac surgery to describe average differences between cerebral, renal, upper body (arm), and lower body (thigh) regional saturation. Furthermore, the correlation between cerebral NIRS and cardiac index (CI) at CPB weaning was evaluated. Twenty-five infants were enrolled: their median weight, age, and body surface area were 3.9 (3.3-6) kg, 111 (47-203) days, and 0.24 (0.22-0.33) m(2) , respectively. Median Aristotle score was 8 (6-10), and vasoactive inotropic score at CPB weaning was 16 (14-25). A total of 17 430 data points were recorded by each sensor: two-way ANOVA showed that time (P < 0.0001) and site (P = 0.0001) significantly affected variations of NIRS values: however, if cerebral NIRS values are excluded, sensor site is no more significant (P = 0.184 in the no circulatory arrest [noCA] group and P = 0.42 in the circulatory arrest [CA] group). Analysis of NIRS saturation changes over time showed that, at all sites, average NIRS values increased after CPB start, even if the increase of cerebral saturation was less intense than other sites (P < 0.0001). Detailed analysis of interaction between site of NIRS measurement and time point showed that cerebral NIRS (ranging from 65 to 75%) was always significantly lower than that of other channels (P < 0.0001) that tended to be in the range of oversaturation (80-90%), especially during the CPB phase. Average cerebral NIRS values of patients who did not undergo circulatory arrest (CA) during CPB, 10 min after CPB weaning, were associated with average CI values with a significant correlation (r = 0.7, P = 0.003). In conclusion, during CPB, cerebral NIRS values are expected to remain constantly lower than somatic sensors, which instead tend to show similar elevated saturations, regardless of their position. Based on these results, positioning of noncerebral NIRS sensors during CPB without CA may be questioned.

Comparison of the transcutaneous bilirubinometers BiliCare and Minolta JM-103 in late preterm and term neonates

Abstract Objectives: To assess the agreement of transcutaneous bilirubin (TcB) measurement with the Bilicare™ System in comparison to TcB measured with JM-103™ and total serum bilirubin (TSB). Methods: Caucasian infants with gestational age ≥35 weeks with non-hemolytic jaundice received TcB measurement with both Bilicare™ and JM-103™ devices. TSB was also obtained in infants at risk of phototherapy. Results: We studied 458 infants measuring TcB with Bilicare™ and JM-103™, correlating the results and with TSB. The mean difference ± 2SD between Bilicare™ and JM-103™ TcB was 2.02 ± 4.46 mg/dL and decreased from 2.88 ± 3.17 to 1.20 ± 4.55, and to −0.95 ± 4.58 mg/dL at mild, moderate and high TcB values, respectively. Conclusions: Bilicare™ and JM-103™ TcB measurements are well correlated, but Bilicare™ over-estimates TcB for mild and moderate values and under-estimates it for high values compared to JM-103™. This could increase the prescription of TSB measurements for less serious cases and decrease them in the most worrisome.

Linezolid extracorporeal removal during haemodialysis with high cut-off membrane in critically ill patients

Continuous venovenous haemodialysis with high cut-off membrane (HCO-CVVHD) is often used in critically ill septic patients with acute kidney injury (AKI) to sustain renal function and to remove circulating inflammatory mediators. The aim of this study was to analyse the extracorporeal removal of linezolid and related alterations in pharmacokinetic/pharmacodynamic (PK/PD) parameters during HCO-CVVHD. Three critically ill septic patients with AKI, treated with linezolid and HCO-CVVHD, were prospectively observed. To calculate the extracorporeal clearance of linezolid and the PK parameters, effluent, pre-filter and post-filter samples were contemporaneously collected before linezolid infusion, just after 1-h infusion (maximum serum concentration; C(max)), at 3 h and 6 h after dosing, and before the next dose (trough serum concentration; C(min)). Linezolid C(max) and C(min) (pre-filter) ranged from 10.4-23.5 mg/L and from 2.9-10.3 mg/L. The dialysate saturation coefficient was 0.66-0.85 and the extracorporeal clearance with a diffusive dose of 35 m L/kg/h ranged from 2.1-2.5 L/h. Total linezolid clearance was between 1.7 L/h and 6.3 L/h. The total area under the plasma concentration-time curve (AUC0-∞) ranged from 95.1 mgh/L to 352.9 mgh/L, in accordance with the different clinical conditions. AUCfree/MIC ratios were always <85 for an MIC of 4.0 mg/L, and two of three patients did not reach the optimal PK/PD target of ≥85 even when using an MIC of 2.0 mg/L. Although extracorporeal clearance may affect linezolid total clearance, the clinical features of critically ill septic patients appear to be mainly responsible for the high variability of linezolid serum concentrations.

Comparison between mixed and central venous oxygen saturation in patients with severe acute heart failure after cardiac surgery: A prospective observational study.

[1] Maron BJ, Towbin JA, Thiene G, et al. Contemporary definitions and classification ofthe cardiomyopathies.An American Heart Associationscientific statementfromtheCouncil on Clinical Cardiology, Heart Failure and Transplantation Committee;Quality of Care and Outcomes Research and Functional Genomics and TranslationalBiology Interdisciplinary Working Groups; and Council on Epidemiology andPrevention. Circulation April 2006;113(14):1807–16.[2] Elliott P, Andersson B, Arbustini E, et al. Classification of the cardiomyopathies: aposition statement from the European Society Of Cardiology Working Group onMyocardial and Pericardial Diseases. Eur Heart J Jan 2008;29(2):270–6.0167-5273/

Cost–benefit analysis of the intraoperative parathyroid hormone assay in primary hyperparathyroidism

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Evaluation of candidemia and antifungal consumption in a large tertiary care Italian hospital over a 12-year period

The purpose of this study was to evaluate the usefulness of the routine intraoperative intact parathyroid hormone (IOPTH) assay, the role of unilateral and bilateral cervical exploration and of preoperative imaging, and to do a cost–benefit analysis in parathyroidectomy for primary hyperparathyroidism.

High hERG1 expression in advanced melanoma.

PurposeAn early adequate antifungal therapy based on the knowledge of local epidemiology can reduce the candidemia-attributable mortality and the length of hospitalization. We performed a retrospective study to analyze the epidemiology of candidemia and the antifungal consumption in our hospital.MethodsWe analyzed Candida spp. isolated from the blood, and their susceptibility profile from 2005 to 2016 in Careggi University Hospital, Florence, Italy. We also performed a stratified analysis by clinical setting where Candida spp. were isolated (Medical Wards, Surgery, Intensive Care Unit-ICU). Then, we retrospectively reviewed the annual consumption of antifungal agents and calculated the defined daily dosing for 10,000 hospital days.ResultsThe rate of candidemia was higher in ICU than other settings and Candida albicans was the first cause of candidemia (61.2%). After adjustment for hospital days, the rate of C. albicans showed a statistically significant parabolic trend (p < 0.001), with a peak of incidence in 2010. After 2010, we observed a reduction of candidemia due to both C. albicans and non-albicans species. Between 2005 and 2015, we reported an increasing increased use of echinocandins. As far as resistance profile is concerned, only one Candida glabrata isolate was resistant to caspofungin (1.9%) and 30% of C. glabrata were resistant to fluconazole.ConclusionsOur data describe C. albicans as the first cause of candidemia in all the studied settings and the low rate of echinocandin resistance, despite their increased use over the study period. ICU was confirmed as the setting with the highest incidence of candidemia.

Lung Ultrasound for the Differential Diagnosis of Respiratory Distress in Neonates

Cutaneous melanoma represents the main cause of death among skin cancers. The thickness of the lesion at diagnosis is one of the most important prognostic indicators for survival, which is good for thin melanomas (⩽1 mm) and worsens as thickness increases. Nevertheless, it is not rare to observe disease progression of thin melanomas or, conversely, a good outcome for those melanomas considered to be at high risk, according to the classical prognostic criteria. In the present paper, we analysed for the first time the expression of the hERG1 protein, a potassium channel frequently overexpressed and misexpressed in cancers, in cutaneous melanocytic lesions. The analysis was carried out on archival samples relative to (a) typical melanocytic nevi, (b) atypical melanocytic nevi, (c) thin (<1 mm) melanomas from patients who survived at least 10 years after surgery, (d) thick (>4 mm) melanomas from patients who died for melanoma and (e) melanoma metastases. Samples were analysed by immunohistochemistry using an hERG1-specific antibody. We showed that primary cutaneous melanomas with a thickness greater than 4 mm as well as metastatic melanoma lesions are characterized by a high level of hERG1 expression. Conversely, thin melanomas and benign melanocytic lesions (e.g. typical and atypical melanocytic nevi) express hERG1 at significantly lower levels. Although still preliminary, the data presented here enable us to consider hERG1 as a novel candidate biomarker for aggressive melanoma.