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Biomedical subjects

M Antonelli

Publications and source records attributed to M Antonelli.

At least 19 recordsLinked to original sources

Secondary effluent disinfection: PAA long term efficiency.

The paper summarizes the results of a bench-scale study to evaluate the long-term disinfection efficiency of peracetic acid (PAA). Bacterial counts were repeated 5, 24, and 29 h after the end of the disinfection test, to simulate real re-growth conditions (no residual quenching) and, for the 5 h interval, the potential re-growth (quenching of residual PAA). Fecal coliforms, Escherichia coli, and total heterotrophic bacteria (THB) were enumerated by traditional plate count technique; THB were also enumerated by cytometry. After disinfection, the residual PAA concentration became negligible in about 5 to 11 h, depending on the tested doses. Microbial counts showed that no appreciable re-growth took place after 29 h for coliform group bacteria. For THB, the previously cited enumeration techniques gave different results in re-growth tests, especially for the lowest PAA doses. Indeed plate count technique evaluates the ability to form colonies, while cytometry enumerates intact membrane cells. No regrowth took place, even when no residual disinfectant was present, suggesting that bacteria are unable, even at the lowest doses, to repair damage caused by the PAA disinfecting action. PAA was found to be an efficient disinfecting agent, not only as a bacteriostatic, but also as a bactericide.

Bacteria↗

Noninvasive ventilation in childhood acute neuromuscular respiratory failure: a pilot study.

BACKGROUND: Over a 36-month study period, 10 nonconsecutive neuromuscular pediatric patients (6 infants, mean age 10.16 months, and 4 children, mean age 9.3 years) presenting with acute respiratory failure (ARF) were treated by noninvasive positive pressure ventilation (NPPV). All patients required immediate respiratory support and fulfilled our intubation criteria. OBJECTIVE: The aim of the study was to verify if early NPPV was able to avoid endotracheal intubation and to improve both oxygenation and ventilation within 24 h from admission in this clinical setting. PATIENTS AND METHODS: A prospective pilot study was carried out on neuromuscular patients admitted to the pediatric intensive care unit (PICU) of the Catholic University of Rome because of ARF and managed exclusively with NPPV for at least 24 h following admission. All patients were treated using a flow-triggered mechanical ventilator through a face mask or using the new helmet interface. RESULTS: Eight patients were successfully ventilated during the observation period and 2 early failures occurred. Among children undergoing face mask NPPV, the PaO(2)/FiO(2) ratio increased from a median value of 75 (range 48-149) to 240 (range 133-385; p < 0.001) and 328 (range 180-371; p < 0.001) at selected time points (3 and 12 h after NPPV introduction, respectively); the alveolar-to-arterial oxygenation difference showed a similar trend, i.e. decreasing from a median value of 589 (range 213-659) to 128 (range 62-527; p < 0.01) and 69 (range 45-207; p < 0.001), respectively. Hypercarbic ARF resolved within 6 h from admission even in the most severe cases. CONCLUSIONS: NPPV was a safe and effective first-line therapeutic approach in hypoxemic ARF children/infants with neuromuscular disease. It seems of importance to identify children with neuromuscular disorders who may be able to achieve residual ventilator-free breathing and to perform an NPPV trial avoiding tracheal intubation. Life-threatening respiratory distress and very young age should not preclude NPPV application in the PICU setting. The new helmet interface represents a promising tool for noninvasive ventilation in older children.

Acute Disease↗

Enoximone in cardiac arrest caused by propranolol: two case reports.

We report two clinical cases of cardiac arrest, the former due to an adverse effect of intravenous (i.v.) propranolol in a patient with systemic sclerosis, the latter from a propranolol suicidal overdose. In both cases, conventional advanced life support (ALS) was ineffective but both patients eventually responded to the administration of enoximone, a phosphodiesterase III (PDE III) inhibitor. After the arrest, both patients regained consciousness and were discharged home. The chronotropic and inotropic effects of PDE III inhibitors are due to inhibition of intracellular PDEIII and are therefore unaffected by beta-blockers. These cases suggest that PDEIII inhibitors may be useful in restoring spontaneous circulation in cardiac arrest associated with beta-blocker administration when standard ALS is ineffective.

Adrenergic beta-Antagonists↗

A chart of failure risk for noninvasive ventilation in patients with COPD exacerbation.

Knowing the likelihood of failure of noninvasive positive pressure ventilation (NPPV) in patients with exacerbation of chronic obstructive pulmonary disease (COPD) could indicate the best choice between NPPV and endotracheal intubation instituted earlier. For this purpose, two risk charts were designed (at admission and after 2 h of NPPV) that included all relevant measurable clinical prognostic indicators derived from a population representing the patients seen routinely in clinical practice. Risk stratification of NPPV failure was assessed in 1,033 consecutive patients admitted to experienced hospital units, including two intensive care units, six respiratory intermediate care units, and five general wards. NPPV was successful in 797 patients. Patients with a Glasgow Coma Score <11, acute physiology and chronic health evaluation (APACHE) II > or =29, respiratory rate > or =30 breaths x min(-1) and pH at admission <7.25 have a predicted risk of failure >70%. A pH <7.25 after 2 h greatly increases the risk (>90%). The risk charts were validated on an independent group of 145 consecutive COPD patients treated with NPPV due to an acute ventilatory failure episode. To identify patients with a probability of failure >50%, the sensitivity and specificity were 33% and 96.7% on admission and 52.9% and 94.1% after 2 h of NPPV, respectively. The prediction chart, based on data from the current study, can function as a simple tool to predict the risk of failure of noninvasive positive pressure ventilation and thus improve clinical management of patients tailoring medical intervention.

APACHE↗

Central venous catheters. Observations on the implantation technique and its complications.

The growing utilization of central venous catheterism is linked to the necessity of treating with an always larger number of hospitalized and nonhospitalized patients. The technological development provided us with different devices and materials for specific indications. In the majority of cases the central venous catheter is positioned through direct puncture of a central vein using Seldinger method. The vessels used for the catheterism are: the internal jugular vein, the subclavian vein and femoral vein. The choice of the vein to use is influenced by the operator's experience and by factors depending on the patient. The internal jugular vein via posterior or median and the subclavian vein via subclavicular are the most used sites in the central venous catheterism. However, also the femoral vein can be considered a resource when the clinical conditions of the patient render problematic the positioning in the above mentioned sites. The positioning into the internal jugular vein is generally burdened with a very low risk of pneumothorax and other potentially dangerous complications for the patient. The femoral vein is generally burdened with a larger incidence of thrombosis and infections. The subclavian vein, even if it is the most used, is burdened with a larger incidence of immediate or retarded pneumothorax and accidental venous puncture. The most frequent immediate complications for catheterism are the arterial puncture, pneumothorax, arrhythmias and the wrong positioning. Among the late complications there are the catheter infections correlated, catheter and vessel thrombosis. The use of a proper technique, completed by the operator's experience and the right management of the device, lead to a decrease of the risk level related to the central venous catheterism.

Catheterization, Central Venous↗

Successful treatment with enoximone for severe poisoning with atenolol and verapamil: a case report.

Combined poisoning with calcium channel blockers (CCBs) and beta-blockers is usually associated with severe hypotension and heart failure. Due to the block of the beta receptors, treatment with adrenergic agonists, even at high doses, can be insufficient, and beta-independent inotropes, such as glucagon, may be required. Phosphodiesterase III (PDEIII) inhibitors represent a possible alternative to glucagon in these cases as they have an inotropic effect which is not mediated by a beta receptor.

Adrenergic Agonists↗

New advances in the use of noninvasive ventilation for acute hypoxaemic respiratory failure.

Noninvasive ventilation (NIV) includes various techniques for augmenting alveolar ventilation without an endotracheal airway. The theoretical advantages of this approach include avoiding the complications associated with endotracheal intubation, improving patient comfort, preserving airway defence mechanisms, speech and swallowing. The successful application of NIV in hypoxaemic acute respiratory failure (ARF) of varied etiologies has been extensively described but success rate is strictly dependent on ARF etiology and until today the application of NIV strategies in the setting of hypoxaemic ARF is controversial. Larger, controlled studies are required to clarify the role of NIV in the setting of hypoxaemic ARF. The correct choice of the patient ventilator interface is a crucial issue in noninvasive ventilation. The study of new interfaces could improve tolerability reducing the noninvasive ventilation failure rate.

Acute Disease↗

Noninvasive vs. conventional mechanical ventilation in patients with chronic obstructive pulmonary disease after failure of medical treatment in the ward: a randomized trial.

OBJECTIVE: We conducted a randomized prospective study comparing noninvasive positive pressure ventilation (NPPV) with conventional mechanical ventilation via endotracheal intubation (ETI) in a group of patients with chronic obstructive pulmonary disease who failed standard medical treatment in the emergency ward after initial improvement and met predetermined criteria for ventilatory support. DESIGN AND SETTING: Prospective randomized study in a university hospital 13-bed general ICU. PATIENTS: Forty-nine patients were randomly assigned to receive NPPV (n=23) or conventional ventilation (n=26). RESULTS: both NPPV and conventional ventilation significantly improved gas exchanges. The two groups had similar length of ICU stay, number of days on mechanical ventilation, overall complications, ICU mortality, and hospital mortality. In the NPPV group 11 (48%) patients avoided intubation, survived, and had a shorter duration of ICU stay than intubated patients. One year following hospital discharge the NPPV group had fewer patients readmitted to the hospital (65% vs. 100%) or requiring de novo permanent oxygen supplementation (0% vs. 36%). CONCLUSIONS: The use of NPPV in patients with chronic obstructive pulmonary disease and acute respiratory failure requiring ventilatory support after failure of medical treatment avoided ETI in 48% of the patients, had the same ICU mortality as conventional treatment and, at 1-year follow-up was associated with fewer patients readmitted to the hospital or requiring for long-term oxygen supplementation. An editorial regarding this article can be found in the same issue (http://dx.doi.org/10.1007/s00134-002-1503-3).

Aged↗

Effects of acid-base abnormalities on blood capacity of transporting CO(2): adverse effect of metabolic acidosis.

OBJECTIVE: To investigate the effects of some acid-base abnormalities on blood capacity of transporting CO(2). DESIGN: Prospective study. SETTING: General and Cardiosurgical ICUs of a University hospital. PATIENTS: Six groups of ten patients characterized by: metabolic alkalosis; respiratory alkalosis; absence of acid-base abnormalities; metabolic acidosis; uncompensated respiratory acidosis; and compensated respiratory acidosis. MEASUREMENTS AND RESULTS: The CO(2) dissociation curve, Haldane effect, and the ratio Ra-v between Ca-vCO(2) and Pa-vCO(2) were calculated from arterial and mixed-venous blood gas analyses. The CO(2) dissociation curve was shifted upwards by metabolic alkalosis and compensated respiratory acidosis and downwards by metabolic acidosis. The slope of the curve was unaffected, but CO(2) transport not due to Haldane effect was significantly lower in respiratory acidosis since the slope was less steep at higher PCO(2) values. In comparison with controls, patients affected by metabolic acidosis showed lower Haldane effect values (0.18+/-0.15 vs 0.59+/-0.26 ml of CO(2) per ml of arterial-mixed venous O(2) content difference; P <.05) and Ra-v values (0.43+/-0.10 vs 0.84+/-0.17 ml of CO(2) transported by 100 ml of blood per Torr of arterial-mixed venous PCO(2) gradient; P <.05). CONCLUSIONS: Our findings suggest that acid-base abnormalities, particularly metabolic acidosis, markedly affect blood capacity of transporting CO(2) and may worsen tissue hypercarbia associated with hypoperfusion. However, because of possible errors due to small measurements and the assumptions of the method, in the future definitive clarification will require the construction of original CO(2) dissociation curves for each acid-base abnormality.

Acidosis↗

Comparison of two different protocols of neonatal screening for cystic fibrosis.

The results of two different protocols of neonatal cystic fibrosis (CF) screening in the Lazio region of Italy are reported. The first study, conducted from 1992 to 2000 on about 200,000 newborns, consisted of an immunoreactive trypsin (IRT) protocol without mutation analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, referred to as the IRT/IRT protocol. Approximately 5% of the newborns with a positive first IRT test were also positive at the second test; approximately 57% of the newborns with a high IRT level at the second test were subsequently found to be affected by CF. In September 1998, a second protocol that included mutation analysis (IRT/DNA/IRT protocol) was started. Comparison of the two different screening protocols in terms of sensitivity in detecting CF patients demonstrated that the IRT/DNA/IRT protocol is more effective because it is able to detect a higher number of CF patients than the IRT/IRT protocol. In the same period, in addition to the overall diagnosis performed on a screening basis, 64 other subjects were identified as being affected by CF on the basis of symptomatic findings. The overall incidence of CF (screening + symptoms) was 1 : 2982, while that for carriers was 1 : 27. The sensitivity of the screening program increased over the period from 1992 to 2000, with the enhanced sensitivity in the past 2 years being due to the introduction of the IRT/DNA/IRT protocol.

Cystic Fibrosis↗

Effects of low-dose alfentanil administration on central respiratory drive and respiratory pattern in spontaneously breathing ASA 1 patients.

The aim of this study was to assess the short-term effects of the administration of low doses of alfentanil on respiratory drive and respiratory pattern. We studied 17 ASA I patients scheduled for minor surgery or endoscopic procedures. During spontaneous ventilation, Respiratory Rate, Tidal Volume, Total Respiratory Cycle, Inspiratory and Expiratory Time, Mean Inspiratory Flow, P0.1, S(a)O(2) and EtCO(2) were all measured. The inspired oxygen concentration was 21% and measurements were made at baseline, 5 min (T1), 10 min (T2) and 15 min (T3) following an intravenous bolus injection 10 microg.kg(-1) alfentanil. The administration of alfentanil produced a significant (p < 0.05) reduction in S(a)O(2), minute volume and P0.1. In ASA I spontaneously breathing patients, the pre-operative administration of low doses of alfentanil can initially reduce the respiratory centre activity leading to a reduction in minute volume and S(a)O(2). We therefore recommend careful monitoring of cardio-respiratory function in ASA I patients, following the administration of alfentanil.

Alfentanil↗

Simultaneous cycle sequencing assessment of (TG)m and Tn tract length in CFTR gene.

The lengths of the dinucleotide (TG)m and mononucleotide Tn repeats, both located at the intron 8/exon 9 splice acceptor site of the cystic fibrosis transmembrane conductance regulator (CFTR) gene whose mutations cause cysticfibrosis (CF), have been shown to influence the skipping of exon 9 in CFTR mRNA. This exon 9-skipped mRNA encodes a nonfunctional protein and is associated with various clinical manifestations in CF As a result of growing interest in these repeats, several assessment methods have been developed, most of which are, however, cumbersome, multi-step, and time consuming. Here, we describe a rapid methodfor the simultaneous assessment of the lengths of both (TG)m and Tn repeats, based on a nonradioactive cycle sequencing procedure that can be performed even without DNA extraction. This method determines the lengths of the (TG)m and Tn tracts of both alleles, which in our samples ranged from TG8 to TG12 in the presence of T5, T7, and T9 alleles, and also fully assesses the aplotypes. In addition, the repeats in the majority of these samples can be assessed by single-strand sequencing, with no need to sequence the other strand, thereby saving a considerable amount of time and effort.

Alleles↗

Closed versus open suctioning techniques.

Airway suctioning is classically performed with the disconnection of the patient from the ventilator and the introduction of the suction catheter into the endotracheal tube. Alternatively, it can be accomplished with a closed suctioning system included in the ventilatory circuit, allowing to introduce the suction catheter into the airways without disconnecting the patient from the ventilator. The closed-suction system has some advantages compared to the conventional, open-suction technique. It can be helpful in limiting environmental, personnel and patient contamination and in preventing the loss of lung volume and the alveolar derecruitment associated with standard suctioning in the severely hypoxemic patients. However, the impact of the closed system on ventilator-associated pneumonia as well as its cost-effectiveness and the influence of such devices with ventilatory support remain to be assessed.

Humans↗

Predictors of failure of noninvasive positive pressure ventilation in patients with acute hypoxemic respiratory failure: a multi-center study.

CONTEXT: In patients with hypoxemic acute respiratory failure (ARF), randomized studies have shown noninvasive positive pressure ventilation (NPPV) to be associated with lower rates of endotracheal intubation. In these patients, predictors of NPPV failure are not well characterized. OBJECTIVE: To investigate variables predictive of NPPV failure in patients with hypoxemic ARF. DESIGN: Prospective, multicenter cohort study. SETTING: Eight Intensive Care Units (ICU) in Europe and USA. PATIENTS: Of 5,847 patients admitted between October 1996 and December 1998, 2,770 met criteria for hypoxemic ARF. Of these, 2,416 were already intubated and 354 were eligible for the study. RESULTS: NPPV failed in 30% (108/354) of patients. The highest intubation rate was observed in patients with ARDS (51%) or community-acquired pneumonia (50%). The lowest intubation rate was observed in patients with cardiogenic pulmonary edema (10%) and pulmonary contusion (18%). Multivariate analysis identified age > 40 years (OR 1.72, 95% CI 0.92-3.23), a simplified acute physiologic score (SAPS II) > or = 35 (OR 1.81, 95% CI 1.07-3.06), the presence of ARDS or community-acquired pneumonia (OR 3.75, 95% CI 2.25-6.24), and a PaO2:FiO2 < or = 146 after 1 h of NPPV (OR 2.51, 95% CI 1.45-4.35) as factors independently associated with failure of NPPV. Patients requiring intubation had a longer duration of ICU stay ( P < 0.001), higher rates of ventilator-associated pneumonia and septic complications ( P < 0.001), and a higher ICU mortality ( P < 0.001). CONCLUSIONS: In hypoxemic ARF, NPPV can be successful in selected populations. When patients have a higher severity score, an older age, ARDS or pneumonia, or fail to improve after 1 h of treatment, the risk of failure is higher.

Acute Disease↗