1,720,968 research outputs found
THE PLEURAL EFFUSION IN ALI/ARDS PATIENTS: A CT SCAN STUDY
No full textINTRODUCTION. The pleural effusion in patients with ALI/ARDS is a quite common finding. However,
there are only few data which evaluated the presence/amount of pleural effusion and its clinical
consequences. We aimed to compute the amount of pleural effusion and the impairment of gas exchange
and the severity of lung disease.
METHODS. Patients were studied at PEEP 5, 15 and 45 cmH2O of airway pressure during an end
expiratory pause, by lung spiral CT scan (exposure 120 Kv-250 mA). Gas exchange was measured at
the two PEEP levels. The outline of the lungs and of pleural effusion were manually delineated in each
image by a physician using a dedicated software (Soft-EFilm University of Milan). Lung recruitability
was computed as the fraction of total lung weight which regains inflation from 5 to 45 cmH2O of airway
pressure. Patients were grouped according to the median value of the amount of pleural effusion.
RESULTS. 68 ALI/ARDS patients mechanically ventilated (age 55±17 yrs, BMI 25±5 Kg/m2,
PaO2/FiO2 200±77, PEEP 11.1±3.0 cmH2O, tidal volume 8.8±1.9 ml/Kg) were enrolled. The
median pleural effusion was 293 ml (range 0-1023 ml).
In table data are presented as mean ± SD.
TABLE 1.
Lower pleural effusion Higher pleural effusion
PaO2 (mmHg) 79±21 80±26
PaCO2 (mmHg) 42±9 41±8
Age (yrs) 50±18 60±15
Lung weight (gr) 1560±515 1441±496
Lung recruitability (%) 13±10 13±13
p<0.05 vs Lower Effusion
CONCLUSION. The presence of pleural effusion was not related to the impairment of gas exchange
and to the amount of lung disease. Older patients presented a higher amount of pleural effusion probably
due to a reduction of lymph drainage
Extracorporeal CO2 removal to reduce lung hyperinflation in a nonintubated patient with acute COPD exacerbation: case report
No full textIntroduction. COPD exacerbation is treated with CPAP or non-invasive ventilation (NIV). If the non-invasive approach fails, tracheal intubation and mechanical ventilation (MV) become mandatory, despite their detrimental side effects in the COPD hyperinflated lungs.
Case report. In a patient with severe respiratory acidosis due to COPD exacerbation (pH 7.22, pCO2
98, pO2 71, FiO2 0,45, RR 40 on NIV), we decided to reduce the need to ventilate using the extracorporeal CO2 removal by an artificial lung (ECCO2-R), so allowing the natural deflation of the lungs, avoiding tracheal intubation and leaving the patient in spontaneous breathing.
Dyspnoea immediately improved after starting the veno-venous (V-V) femoro-femoral bypass:
blood flow 2 L/min and slow increase of gas flow from 1 up to 4 L/min. After 48 hours, almost complete extracorporeal clearance of CO2 production was obtained, leading to sharp decrease of RR and oesophageal pressure swing. Chest X-ray confirmed the reduction of the lung hyperinflation.
We then reduced the extracorporeal CO2 removal, by progressive decrease of gas flow. The patient maintained an acceptable equilibrium with no dyspnea, good breathing coordination and gas exchange (pH 7.45, pCO2 61, pO2 74, FiO2 0,45). The V-V by-pass was removed on day 6 and the patient discharged from the ICU the day after. At six months she is well and has no oxygen need.
Conclusion. In patients with acute severe COPD exacerbation, who fail NIV, the use of V-V ECCO2-R on spontaneous breathing may treat respiratory failure and reduce dynamic
hyperinflation, avoiding the detrimental effects of tracheal intubation and MV
The rule regulating pH changes during crystalloid infusion
No full textPurpose: To define the rule according to which crystalloid solutions characterized by different strong ion difference (SID) modify the acid-base variables of human plasma. Methods: With a previously validated software, we computed the effects of diluting human plasma with crystalloid solutions ([SID] 0-60, 10 mEq/l stepwise). An equation was derived to compute the diluent [SID] required to maintain the baseline pH unchanged, at constant PCO 2 and at every dilution fraction. The results were experimentally tested using fresh frozen plasma, re-warmed at 37°C, equilibrated at PCO 2 35 and 78 mmHg, at baseline and after the infusion of crystalloid solutions with 0, 12, 24, 36, 48 mEq/l [SID]. Results: The mathematical analysis showed that the diluent [SID] required to maintain unmodified the baseline pH equals the baseline bicarbonate concentration, [HCO 3 - ], assuming constant PCO 2 throughout the process. The experimental data confirmed the theoretical analysis. In fact, at the baseline [HCO 3 - ] of 18.3 ± 0.3 mmol/l (PCO 2 35 mmHg) the pH was 7.332 ± 0.004 and remained 7.333 ± 0.003 when the diluting [SID] was 18.5 ± 0.0 mEq/l. At baseline [HCO 3 - ] of 19.5 ± 0.3 mmol/l (PCO 2 78 mmHg) the pH was 7.010 ± 0.003 and remained 7.004 ± 0.003 when the diluting [SID] was 19.1 ± 0.1 mEq/l. At both PCO 2 values infusion with [SID] lower or greater than baseline [HCO 3 - ] led pH to decrease or increase, respectively. Conclusions: The baseline [HCO 3 - ] dictates the pH response to crystalloid infusion. If a crystalloid [SID] equals baseline [HCO 3 - ], pH remains unchanged at constant PCO 2, whereas it increases or decreases if the [SID] is greater or lower, respectively
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
