New insights into the infection of the American cockroach Periplaneta americana nymphs with Metarhizium anisopliae s.l. (Ascomycota: Hypocreales).

AIMS: To study the marked resistance of Periplaneta americana to entomopathogenic Metarhizium anisopliae. METHODS AND RESULTS: The low susceptibility of 4th instar nymphs applied topically with conidia seemed to be related to an active removal of conidia by the cockroach and to a disabled or retarded germination and subsequent development of conidia on the cuticle (up to 80% germination in the next 7 days after application). Inhibitions or delays of germination were related to the composition of the epicuticular fatty acids (30·1% w/w oleic, 28·3% w/w linoleic, 24·5% w/w palmitic and 11·7% w/w stearic acid) reported here. Propagules invading the nymphs through the cuticle took at least 3 days to reach the haemocoel, and no propagules were found after day 8 post-treatment. Strain IP 46 infected >50% of nymphs treated with doses ≥2 × 104  hyphal bodies (HB) nymph-1 and reduced the survival of nymphs ≤50%. Most nymphs (>70%) survived after injection of 6 × 103 and 2 × 103  HB nymph-1 . CONCLUSIONS: Findings emphasize a distinct resistance of nymphs of the American cockroach to infections by M. anisopliae. SIGNIFICANCE AND IMPACT OF THE STUDY: Our findings provide support for the development of biological control of this synanthropic cockroach pest.

Major trauma critical pathway: preliminary results from the monitoring system in the regional network and in a hub center in Rome metropolitan area.

OBJECTIVE: The aim of this study is to collect the two years' data regarding the Integrated Trauma Management System (SIAT) by capturing the activity of its three Hubs in the Italian Lazio Region and test the performance of one of the Hubs' (Fondazione Policlinico Universitario A. Gemelli - IRCCS, FPG -IRCCS) Major Trauma Clinical Pathway's (MTCP) monitoring system, introducing the preliminary results through volume, process and outcome indicators. MATERIALS AND METHODS: A retrospective analysis on SIAT was conducted on years 2016 to 2018, by collecting outcome and timeliness indicators through the Lazio Informative System whereas the MTCP was monitored through set of indicators from the FPG - IRCCS Informative System belonging to randomly selected clinical records of the established period. RESULTS: Hubs managed 11.3% of the 998,240 patients admitted in SIAT. All patients eligible for MTCP were "Flagged", and 83% underwent a CT within 2 hours; intra-hospital mortality was 13% whereas readmission rates 16.9%. CONCLUSIONS: SIAT converges the most severe patients to its Hubs. The MTCP monitoring system was able to measure a total of 9 out of 13 indicators from the original panel. This research may serve as a departing point to conduct a pre-post analysis on the performance of the MTCP.

Clinical and microbiological outcome in septic patients with extremely low 25-hydroxyvitamin D levels at initiation of critical care.

A relationship between vitamin D status and mortality in patients in intensive care units (ICU) has been documented. The present study aims to describe the clinical profile and sepsis-related outcome of critically ill septic patients with extremely low (<7 ng/mL) vitamin D levels at ICU admission. We conducted an observational study in the ICU of a teaching hospital including all patients admitted with severe sepsis/septic shock and undergoing 25-hydroxyvitamin D (25(OH)D) testing within the first 24 hours from admission. We studied 107 patients over 12 months. At ICU admission vitamin D deficiency (≤20 ng/mL) was observed in 93.5% of the patients: 57 (53.3%) showed levels <7 ng/mL. As primary outcome, sepsis-related mortality rate was higher in patients with vitamin D levels <7 ng/mL (50.9% versus 26%). Multivariate regression analysis showed that vitamin D concentration <7 ng/mL on ICU admission (p 0.01) and higher mean SAPS II (p <0.01) score were independent predictors of sepsis-related mortality. Patients with very low vitamin D levels suffered higher rate of microbiologically confirmed infections but a lower percentage of microbiological eradication with respect to patients whose values were >7 ng/mL (80.7% versus 58%, p 0.02; 35.3% versus 68%; p 0.03, respectively). Post hoc analysis showed that, in the extremely low vitamin D group, the 52 patients with pneumonia showed a longer duration of mechanical ventilation (9 days (3.75-12.5 days) versus 4 days (2-9 days), p 0.04) and the 66 with septic shock needed vasopressor support for a longer period of time (7 days (4-10 days) versus 4 days (2-7.25 days), p 0.02). Our results suggest that in critical septic patients extremely low vitamin D levels on admission may be a major determinant of clinical outcome. Benefits of vitamin D replacement therapy in this population should be elucidated.

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.

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.

Cerebral blood flow and metabolic changes produced by repetitive magnetic brain stimulation.

We evaluated cerebral variation in oxyhemoglobin, deoxyhemoglobin, and cytochrome oxidase before and after transcranial magnetic and electrical stimulation in ten healthy volunteers using near-infrared spectroscopy. Immediately after magnetic but not after electric stimulation a significant increase in oxyhemoglobin and a decrease in cytochrome oxidase were observed (P < 0.05). Our data suggest that repetitive transcranial magnetic stimulation induces metabolic activation of the cerebral cortex together with an increase in cerebral blood flow.

[ Physiopathology and treatment of accidental hypothermia]. / Fisiopatologia e trattamento dell'ipotermia accidentale.

Severe hypothermia is seldom observed in our country due to the mild climate. But it can represent a difficult medical problem. Severe hypothermia occurs when body temperature falls below 28 degrees. The victim may be unconscious with a severe depression of vital functions. All such patients should undergo vigorous cardiopulmonary resuscitation and rapid rewarming. The most efficient methods of rewarming are represented by peritoneal irrigation and esophageal thermal tube.

Chest pain caused by tracheostomy tube malposition: the importance of choosing the right tube.

We describe a case of chest pain caused by tracheostomy tube malposition in a 65-year old woman with chronic respiratory failure due to chronic obstructive pulmonary disease. This report highlights the importance of the correct choice of tracheostomy tube devices for mechanically ventilated and/or spontaneously breathing patients.

Diurnal and nocturnal shifts do not influence non-invasive ventilation outcome.

AIM: The aim of this study was to assess if diurnal or nocturnal shifts were independent risk factors for non-invasive ventilation (NIV) failure. METHODS: This was an observational study carried out on 18 patients of the general Intensive Care Unit in Rome. A total number of 189 consecutive patients needing mechanical ventilation for respiratory failure were prospectively enrolled: 82 were treated with NIV as a first line intervention. Of the 107 patients who were initially intubated, 59 patients were extubated; once extubation failed they were treated with NIV. NIV failure was assessed during both the day (between 7 am and 10 pm) and night shifts (between 10 pm and 7 am). RESULTS: Of the 141 total patients who received NIV, 51 experienced failure during the day shifts and 18 during the night shifts. No difference in the median day and night shift TISS-28 values were observed in any patients who failed NIV during both day and night shifts. Causes of NIV failure were similar during both diurnal and nocturnal shifts. The inability to correct gas exchanges was the main reason for failure. CONCLUSION: In a center with NIV expertise, notwithstanding nurse understaffing, diurnal and nocturnal shifts did not affect the rate of NIV failure.

Hypoalbuminaemia does not impair Diprifusor performance during sedation with propofol.

BACKGROUND: About 98% of plasma propofol is bound to albumin. We investigated if severe hypoalbuminaemia may affect the accuracy of a target-controlled infusion (TCI) device, the Diprifusor, during sedation in critically ill patients. METHODS: Ten critically ill hypoalbuminaemic patients (<24 g litre(-1)) and 10 critically ill normoalbuminaemic patients (>32 g litre(-1)) were included in this study. They underwent sedation with propofol, aimed at a Ramsey sedation score of 4-5. The Diprifusor was used to achieve target propofol plasma concentrations that ranged between 0.6 and 1.5 mg litre(-1). Propofol concentration was measured by high-performance liquid chromatography 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 6 h and 8 h after starting TCI. The accuracy of TCI was evaluated by calculating performance errors [PE=100x(measured concentration-predicted concentration)/predicted concentration], absolute and relative individual median performance errors (MDAPE and MDPE) and divergence (the slope of individual regression lines between PEs and time). RESULTS: PEs [median (range)] were -7 (-65, 79) in hypoalbuminaemic patients and -2 (-53, 188) in normoalbuminaemic patients; absolute PEs were 21 (1, 79) and 22 (0, 188). No significant difference was observed between the two groups. MDPE, MDAPE and divergence values were also similar. In most patients the accuracy of TCI increased with time because higher PE values were observed during the first 30 min. CONCLUSIONS: Hypoalbuminaemia does not affect the accuracy of Diprifusor during sedation with propofol in critically ill patients.

[Non-invasive ventilation in intensive care. Update 2000]. / La ventilazione non invasiva in terapia intensiva. Update 2000.

NIV indications and application in critically ill patients have considerably expanded in the last few years: the aim of this paper is to shortly review NIV main indications, on the basis of data from the current scientific literature.

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.

[Home mechanical ventilation: the extra-hospital phase]. / Ventilazione domiciliare. La fase extra-ospedaliera.

Home mechanical ventilation is the choice option, when there are no contraindications of medical or socio-economic order, in all cases of impossible complete weaning from ventilatory support. Easy to use, reliable and size limited positive pressure ventilators lead to a spread diffusion of this technique. In the patient/ventilator interface, tracheostomy is the golden choice for patient with great reduction in spontaneous ventilatory ability. For all other patients, perfectioning of non-invasive access (nasal and oral nasal mask) represent an effective progress. Major limitations in home ventilation are still, up to present, the lack of multidisciplinary structures able to give territorial assistance. Home ventilation therapy in the experience of the Policlinico Universtitario "La Sapienza", Rome is presented.

[Changes in acid-base equilibrium and CO2 output induced by bicarbonate infusion]. / Variazione dell'equilibrio acido-base e dell'eliminazione di CO2 indotte dall'infusione di bicarbonato.

BACKGROUND: Bicarbonate therapy for metabolic acidosis can cause tissue hypercapnia. We tested the hypothesis that CO2 retention is initially confined to blood and that tissue hypercapnia is consequent to blood hypercapnia. DESIGN: prospective study. SETTING: general Intensive Care Unit in an University Hospital. PATIENTS: ten patients, aged 34-84, undergoing fixed mechanical ventilation for stroke, respiratory failure, polytrauma, or coma and presenting fairly stabilized circulatory condition were included in the study providing that definite exclusion criteria were absent. Sodium bicarbonate, 0.08, 0.17, and 0.25 mEq/kg, was infused in 5 minutes during stages A, B, and C. During each stage, before and after bicarbonate infusion, heart rate, arterial pressure, central venous pressure, and PetCO2 were registered and arterial and central venous haemogasanalysis were performed. CO2 output was measured during and after bicarbonate infusion and total CO2 output over basal values was calculated. RESULTS: Heart rate, arterial pressure, central venous pressure did not change in any stage, while PetCO2 increased in all. Following bicarbonate infusion, pH increased more in venous than in arterial blood and was significantly affected by the amount of bicarbonate infused. In arterial blood both PCO2 and total CO2 content (TCO2) increased. In venous blood PCO2 did not change while TCO2 increased so that arterial-venous rl CO2 difference was unaffected. CO2 output changed in no patient but two during stage A, and increased by 0.54 +/- 0.16 mL/kg during stage B and by 1.18 +/- 0.26 mL/kg during stage C so that 14.5 +/- 4.3 and 21.2 +/- 4.7% of given bicarbonate was released as CO2 through the lungs. CO2 output increased after a latency that was significantly shorter during stage C (145 +/- 51 sec) than during stage B (226 +/- 53 sec). CONCLUSIONS: Since arterial-venous TCO2 difference was unaffected and haemodynamic parameters were stable, the conclusion is drawn that CO2 and bicarbonate did not diffuse out of vascular compartment during this study. However CO2 and bicarbonate diffusion out of blood would have occurred if bicarbonate infusion had continued, because CO2 excess was released through the lungs after a latency and extended after the infusion. Consequently, tissue hypercapnia during bicarbonate infusion could probably be prevented by improving CO2 release through the lungs, i.e. by hyperventilating the patient.

Role of desmopressin in the treatment of a case of septic shock refractory to catecholamines.

The authors describe a case of septic shock refractory to high-dose catecholamines after adequate volemic filling, rapidly corrected with the administration of desmopressin at a dose of 0.02 U/min. There are, in the literature, several cases of septic shock refractory to high-dose catecholamines successfully treated with arginine-vasopressin, a selective V1 agonist. This agent can potentially induce coronary vasoconstriction and presents a very difficult weaning, that imposes a slow reduction of the infusion amount. On the contrary, desmopressin does not present those adverse effects and is able to maintain a high renal blood flow, for its prevalent action on V2 instead of V1 receptors.

Zinc and copper metabolism during open-heart surgery.

Zinc and copper changes were studied in plasma, whole blood, urine and myocardium in 15 patients undergoing valve replacement in hypothermic cardiopulmonary bypass with hemodilution. During the cardiopulmonary bypass, a fall in plasma copper and zinc concentration was related to hemodilution. The zinc concentration also decreased in whole blood, but remained unchanged intracellularly. The urinary concentration of both cations, but not the output, decreased at the end of the operation in relation to the baseline values. The myocardial copper and zinc concentrations increased during the aortic cross-clamping period. The possible causes and significance of these changes are considered.

Quantitative cerebral blood flow and metabolism determination in the first 48 hours after severe head injury with a new dynamic SPECT device.

OBJECTIVE: To determine cerebral blood flow (CBF) and metabolism in the acute phase after severe head injury by a new dynamic SPECT device using 133Xenon and to evaluate a possible role of CBF and metabolism in the determination of prognosis. DESIGN: Prospective study. SETTING: General intensive care unit in a universitary teaching hospital. SUBJECTS: 23 severely head injured patients having CT scan and CBF determination, intracranial pressure (ICP) and jugular bulb oxygen saturation monitoring in the first 48 hours. MEASUREMENTS AND MAIN RESULTS: CBF varied from 18.0 to 60.0 ml/100 g/min. No correlation was found between early CBF and severity of trauma evaluated with the Glasgow Coma Score (GCS) (F = 2.151, p = 0.142) and between CBF and prognosis at 6 months evaluated with Glasgow outcome score (GOS) (F = 0.491, p = 0.622: rs = 0.251, p = 0.246). CMRO2 was depressed in relation to the severity of injury, specifically ranging from 0.9 +/- 0.5 ml/100 g/min in patients with GCS 3 to 1.7 +/- 0.8 ml/100 g/min in patients with GCS 6-7. In no patient with CMRO2 less than 0.8 ml/100 g/min was a good outcome observed. A significant correlation was found between GCS and GOS (rs = 0.699, p = 0.0002), between CMRO2 and GOS (F = 4.303, p = 0.031; rs = 0.525, p = 0.013) and between AJDO2 and GOS (F = 3.602, p = 0.046; rs = 0.491, p = 0.017). Fronto-occipital ratio (F/O) of CBF distribution was significantly lower than normal values (chi 2 = 18.658, p = 0.001) but did not correlate either with prognosis (chi 2 = 1.626, p = 0.443) or with severity (chi 2 = 1.913, p = 0.384). CONCLUSIONS: CBF in the first 48 hours after trauma varies within a large range of values and is not correlated with severity and prognosis. Clinical evaluation with GCS and CMRO2 are much more reliable indicators of severity of head trauma and have a significant role in the determination of prognosis. F/O ration is significantly altered from normal values confirming "post-traumatic hypofrontalism" but does not correlate with severity and prognosis.