Final Results of the OPERA Experiment on ν_{τ} Appearance in the CNGS Neutrino Beam

The OPERA experiment was designed to study ν_{μ}→ν_{τ} oscillations in the appearance mode in the CERN to Gran Sasso Neutrino beam (CNGS). In this Letter, we report the final analysis of the full data sample collected between 2008 and 2012, corresponding to 17.97×10^{19} protons on target. Selection criteria looser than in previous analyses have produced ten ν_{τ} candidate events, thus reducing the statistical uncertainty in the measurement of the oscillation parameters and of ν_{τ} properties. A multivariate approach for event identification has been applied to the candidate events and the discovery of ν_{τ} appearance is confirmed with an improved significance level of 6.1σ. |Δm_{32}^{2}| has been measured, in appearance mode, with an accuracy of 20%. The measurement of the ν_{τ} charged-current cross section, for the first time with a negligible contamination from ν[over ¯]_{τ}, and the first direct evidence for the ν_{τ} lepton number are also reported.

Discovery of τ Neutrino Appearance in the CNGS Neutrino Beam with the OPERA Experiment

The OPERA experiment was designed to search for ν_{μ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{μ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{μ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.

Mitral valve endocarditis in a severe burn patient

The authors describe the case of a 40-year-old female with severe burns (85% of total body surface area including the thorax) caused by thermal injury who presented mitral valve endocarditis during intensive care unit stay. Bacterial endocarditis represents a rare cause of fatal septicemia complicating thermal injury. The authors focus on diagnosis and on timing of surgical treatment.

Plasma dopamine concentration and effects of low dopamine doses on urinary output after major vascular surgery

To evaluate plasma dopamine concentration and the effects of low doses infusion on urinary output after abdominal vascular surgery in patients with renal function impairment we performed a prospective clinical study. Twenty hemodynamically stable patients (mean age 66.6 years), with serum creatinine concentration < 2 mg %, who undergoing general anesthesia for major vascular surgery participated. A low dose of dopamine (3 micrograms/kg/min) was administrated to patients with postoperative protracted urinary output < 0.5 ml/kg/hr for at least eight hours. Plasmatic determinations were taken at T0 (no dopamine administration), when urinary output began to increase, or if not, after two hours (T1), at eight (T2), and 24 (T3) hours after the beginning of infusion. After 24 hours the dopamine infusion was stopped and the patient's plasmatic level was measured four hours later (T4). Dopamine plasma concentrations were measured using high-performance liquid chromatography. Plasma dopamine concentration increased in all patients and reached a steady state at T2 (T2 = 76.41 +/- 16.84 ng/ml). Dopamine induced a concentration-dependent increase in urinary output (T0 = 0.45 +/- 0.14; T1 = 1.49 +/- 1.11; T2 = 2.34 +/- 1.44; T3 = 1.57 +/- 0.57; T4 = 0.85 +/- 0.7 ml/kg/hr). Three patients did not have an enhanced urinary output after dopamine infusion; they did have a prolonged clamping time and operation time (162 +/- 24 and 570 +/ 30 min, respectively). We conclude that low dose dopamine induces a dose-dependent increase of urinary output. This phenomenon also has been found in patients when their plasma concentration had not yet reached the steady-state. Lack of responsiveness to dopamine suggests a renal function impairment probably due to the prolonged aortic clamping time.

[Intensity of treatment and severity of illness in the intensive care unit (ICU)]

OBJECTIVE

To investigate the relationship between Therapeutic Intervention Scoring System (TISS), length of ICU stay and severity of illness.

DESIGN

Prospective study lasting 1 year.

SETTING

Two 4-bed surgical-medical ICU.

PATIENTS

All consecutively ICU admitted patients.

METHODS

Every day TISS of each patient during the last 24 h was computed. Age, sex, type of admission, SAPS II and APACHE II, length of ICU stay and hospital outcome were recorded. Out of 446 admissions, 14 were excluded since the ICU stay was < 16 h. Severity of illness was considered in 405 of the remaining 432; total TISS of readmitted patients resulted from all ICU admissions during the same hospital stay.

RESULTS

Median TISS on day 1 was 24 (range 3-58, CI 95% 0.57) and median TISS +/- CI 95% during the first 10 ICU days ranged from 20 to 26. Spearman's correlation coefficient between TISS total and length of stay in ICU was 0.962. Total TISS increased with risk of hospital death predicted by both SAPS II and APACHE II. Total TISS of non surviving patients was significantly (p < 0.001) higher than that of the surviving up to probability of death of 20%.

CONCLUSIONS

Intensity of treatment is essentially steady and total TISS is well related to length of ICU stay. Total TISS increases with increasing risk of hospital death predicted by SAPS II and APACHE II, but it is high especially in non surviving patients with low probability of hospital mortality at the admission.

[Survival in intensive care of patients with chronic obstructive bronchopneumopathy and acute respiratory failure undergoing mechanical ventilation. Retrospective study]

OBJECTIVE

To collect valuable informations for the evaluation of the patients' clinical evolution and to perform a cost-effectiveness analysis on the utilization of resources in the management of patients with chronic obstructive pulmonary disease (COPD) undergoing mechanical ventilation (MV) for acute respiratory failure (ARF).

SETTING

General ICU. University Hospital.

PATIENTS

87 BPCO patients (mean age: 69.6 +/- 8.5) undergoing MV for ARF due to non surgical or traumatic events, for a total of 108 consecutive ICU admissions between January 1983 and December 1993.

METHODS

Retrospective study in which the following data were collected: severity of the underlying chronic respiratory disease before the occurrence of ARF. For this aim patients have been divided into five classes (O-IV) according with ATS classification of dyspnea; causes of ARF; SAPS score; TISS score; OMEGA score; complications occurred in ICU; duration of MV; duration of stay in ICU; ICU and hospital outcome.

RESULTS

In 48 cases (44.4%) clinical history was positive for a severe dyspnea (classes III-IV). Slight airway flogosis or infection were responsible of ARF in 78 cases; pneumonia was present in 24 cases while in 6 cases ARF was due to congestive heart failure. The study population was divided into two groups according with outcome. No statistically significant difference was observed in mean SAPS and TISS scores between the two groups (12.5 +/- 3 vs 13 +/- 4.8 and 18.4 +/- 2.3 vs 19 +/- 4.2). Mean OMEGA score was 155 +/- 11.7 (ES). With reference to ICU outcome the utilization rate or resources was 72.15% with a mean loss of resources of 43.2. Compli-cations were manly due to airway infection (16 cases) which was responsible in one case of the patient's death. Overall incidence of complications was relatively low and five of them led to patients' death in ICU. Mean duration of MV did not differ between the two groups (13.4 +/- 11.7 vs 14.3 +/- 11.7) but it was significantly longer in those patients whose clinical history was positive for severe dyspnea (classes III and IV) than in patients without this report (16.6 +/- 14.9 vs 10.9 +/- 6.9; p < 0.05). Mean stay in ICU did not differ significantly between survivors and non-survivors (21.4 +/- 18.6 vs 19.7 +/- 13). ICU mortality rate was 6.48% (7 patients) and hospital mortality rate was 20.3% (22 patients).

CONCLUSIONS

Our results demonstrate that hospital outcome in COPD patients with ARF requiring mechanical ventilation is quite good. Prolonged mechanical ventilation and--severity of underlying chronic respiratory disease do not affect significatively the prognosis. The high costs of the treatment of these patients are counterbalanced by a good efficiency of utilization of resources and appreciable clinical results.