Background Whether respiratory physiology of COVID-19-induced respiratory failure is different from acute respiratory distress syndrome (ARDS) of other etiologies is unclear. We conducted a single-center study to describe respiratory mechanics and response to positive end-expiratory pressure (PEEP) in COVID-19 ARDS and to compare COVID-19 patients to matched-control subjects with ARDS from other causes. Methods Thirty consecutive COVID-19 patients admitted to an intensive care unit in Rome, Italy, and fulfilling moderate-to-severe ARDS criteria were enrolled within 24 h from endotracheal intubation. Gas exchange, respiratory mechanics, and ventilatory ratio were measured at PEEP of 15 and 5 cmH 2 O. A single-breath derecruitment maneuver was performed to assess recruitability. After 1:1 matching based on PaO 2 /FiO 2 , FiO 2 , PEEP, and tidal volume, COVID-19 patients were compared to subjects affected by ARDS of other etiologies who underwent the same procedures in a previous study. Results Thirty COVID-19 patients were successfully matched with 30 ARDS from other etiologies. At low PEEP, median [25th–75th percentiles] PaO 2 /FiO 2 in the two groups was 119 mmHg [101–142] and 116 mmHg [87–154]. Average compliance (41 ml/cmH 2 O [32–52] vs. 36 ml/cmH 2 O [27–42], p = 0.045) and ventilatory ratio (2.1 [1.7–2.3] vs. 1.6 [1.4–2.1], p = 0.032) were slightly higher in COVID-19 patients. Inter-individual variability (ratio of standard deviation to mean) of compliance was 36% in COVID-19 patients and 31% in other ARDS. In COVID-19 patients, PaO 2 /FiO 2 was linearly correlated with respiratory system compliance ( r = 0.52 p = 0.003). High PEEP improved PaO 2 /FiO 2 in both cohorts, but more remarkably in COVID-19 patients ( p = 0.005). Recruitability was not different between cohorts ( p = 0.39) and was highly inter-individually variable (72% in COVID-19 patients and 64% in ARDS from other causes). In COVID-19 patients, recruitability was independent from oxygenation and respiratory mechanics changes due to PEEP. Conclusions Early after establishment of mechanical ventilation, COVID-19 patients follow ARDS physiology, with compliance reduction related to the degree of hypoxemia, and inter-individually variable respiratory mechanics and recruitability. Physiological differences between ARDS from COVID-19 and other causes appear small.
BackgroundBreast and cervical cancer screening are widely recognized as effective preventive procedures in reducing cancer mortality. The aim of this study was to evaluate the impact of socioeconomic disparities in the uptake of female screening in Italy, with a specific focus on different types of screening programs.MethodsA cross-sectional study was conducted using data from the 2004-2005 national health interview survey. A sample of 15, 486 women aged 50-69 years for mammography and one of 35, 349 women aged 25-64 years for Pap smear were analysed. Logistic regression models were used to estimate the association between socioeconomic factors and female screening utilization.ResultsEducation and occupation were positively associated with attendance to both screening. Women with higher levels of education were more likely to have a mammogram than those with a lower level (OR = 1.28; 95% CI = 1.10-1.49). Women of intermediate and high occupational classes were more likely to use breast cancer screening (OR = 1.77; 95% CI = 1.55-2.03, OR = 1.63; 95% CI = 1.40-1.91) compared to unemployed women. Women in the highest occupational class had a higher likelihood of cervical cancer screening compared to those in the lowest class (OR = 1.81; 95% CI = 1.63-2.01). Among women who attended screening, those with lower levels of education and lower occupational classes were more likely than more advantaged women to attend organized screening programs rather than being screened on the basis of their own initiative.ConclusionsInequalities in the uptake of female screening widely exist in Italy. Organized screening programs may have an important role in increasing screening attendance and tackling inequalities.
Background: Airway closure causes lack of communication between proximal airways and alveoli, making tidal inflation start only after a critical airway opening pressure is overcome. The authors conducted a matched cohort study to report the existence of this phenomenon among obese patients undergoing general anesthesia.Methods: Within the procedures of a clinical trial during gynecological surgery, obese patients underwent respiratory/lung mechanics and lung volume assessment both before and after pneumoperitoneum, in the supine and Trendelenburg positions, respectively. Among patients included in this study, those exhibiting airway closure were compared to a control group of subjects enrolled in the same trial and matched in 1:1 ratio according to body mass index.results: Eleven of 50 patients (22%) showed airway closure after intubation, with a median (interquartile range) airway opening pressure of 9 cm H 2 O (6 to 12). With pneumoperitoneum, airway opening pressure increased up to 21 cm H 2 O (19 to 28) and end-expiratory lung volume remained unchanged (1,294 ml [1,154 to 1,363] vs. 1,160 ml [1,118 to 1,256], P = 0.155), because end-expiratory alveolar pressure increased consistently with airway opening pressure and counterbalanced pneumoperitoneum-induced increases in end-expiratory esophageal pressure (16 cm H 2 O [15 to 19] vs. 27 cm H 2 O [23 to 30], P = 0.005). Conversely, matched control subjects experienced a statistically significant greater reduction in end-expiratory lung volume due to pneumoperitoneum (1,113 ml [1,040 to 1,577] vs. 1,000 ml [821 to 1,061], P = 0.006). With airway closure, static/dynamic mechanics failed to measure actual lung/respiratory mechanics. When patients with airway closure underwent pressure-controlled ventilation, no tidal volume was inflated until inspiratory pressure overcame airway opening pressure.conclusions: In obese patients, complete airway closure is frequent during anesthesia and is worsened by Trendelenburg pneumoperitoneum, which increases airway opening pressure and alveolar pressure: besides preventing alveolar derecruitment, this yields misinterpretation of respiratory mechanics and generates a pressure threshold to inflate the lung that can reach high values, spreading concerns on the safety of pressure-controlled modes in this setting.
BACKGROUND: The efficacy of noninvasive oxygenation strategies (NIOS) in treating COVID-19 disease is unknown. We conducted a prospective observational study to assess the rate of NIOS failure in subjects treated in the ICU for hypoxemic respiratory failure due to COVID-19. METHODS: Patients receiving first-line treatment NIOS for hypoxemic respiratory failure due to COVID-19 in the ICU of a university hospital were included in this study; laboratory data were collected upon arrival, and 28-d outcome was recorded. After propensity score matching based on Simplified Acute Physiology (SAPS) II score, age, P aO 2 =F IO 2 and P aCO 2 at arrival, the NIOS failure rate in subjects with COVID-19 was compared to a previously published cohort who received NIOS during hypoxemic respiratory failure due to other causes. RESULTS: A total of 85 subjects received first-line treatment with NIOS. The most frequently used methods were helmet noninvasive ventilation and highflow nasal cannula; of these, 52 subjects (61%) required endotracheal intubation. Independent factors associated with NIOS failure were SAPS II score (P 5 .009) and serum lactate dehydrogenase at enrollment (P 5 .02); the combination of SAPS II score 6 33 with serum lactate dehydrogenase 6 405 units/L at ICU admission had 91% specificity in predicting the need for endotracheal intubation. In the propensity-matched cohorts (54 pairs), subjects with COVID-19 showed higher risk of NIOS failure than those with other causes of hypoxemic respiratory failure (59% vs 35%, P 5 .02), with an adjusted hazard ratio of 2 (95% CI 1.1-3.6, P 5 .01). CONCLUSIONS: As compared to hypoxemic respiratory failure due to other etiologies, subjects with COVID-19 who were treated with NIOS in the ICU were burdened by a 2-fold higher risk of failure. Subjects with a SAPS II score 6 33 and serum lactate dehydrogenase 6 405 units/L represent the population with the greatest risk.
Background and purpose: The objective of this study was to assess the neurological manifestations in a series of consecutive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive patients, comparing their frequency with a population hospitalized in the same period for flu/respiratory symptoms, finally not related to SARS-CoV-2. Methods: Patients with flu/respiratory symptoms admitted to Fondazione Policlinico Gemelli hospital from 14 March 2020 to 20 April 2020 were retrospectively enrolled. The frequency of neurological manifestations of patients with SARS-CoV-2 infection was compared with a control group. Results: In all, 213 patients were found to be positive for SARS-CoV-2, after reverse transcriptase polymerase chain reaction on nasal or throat swabs, whilst 218 patients were found to be negative and were used as a control group. Regarding central nervous system manifestations, in SARS-CoV-2-positive patients a higher frequency of headache, hyposmia and encephalopathy always related to systemic conditions (fever or hypoxia) was observed. Furthermore, muscular involvement was more frequent in SARS-CoV-2 infection. Conclusions: Patients with COVID-19 commonly have neurological manifestations but only hyposmia and muscle involvement seem more frequent compared with other flu diseases.
BackgroundHigh-flow oxygen therapy via nasal cannula (HFOTNASAL) increases airway pressure, ameliorates oxygenation and reduces work of breathing. High-flow oxygen can be delivered through tracheostomy (HFOTTRACHEAL), but its physiological effects have not been systematically described. We conducted a cross-over study to elucidate the effects of increasing flow rates of HFOTTRACHEAL on gas exchange, respiratory rate and endotracheal pressure and to compare lower airway pressure produced by HFOTNASAL and HFOTTRACHEAL.MethodsTwenty-six tracheostomized patients underwent standard oxygen therapy through a conventional heat and moisture exchanger, and then HFOTTRACHEAL through a heated humidifier, with gas flow set at 10, 30 and 50 L/min. Each step lasted 30 min; gas flow sequence during HFOTTRACHEAL was randomized. In five patients, measurements were repeated during HFOTTRACHEAL before tracheostomy decannulation and immediately after during HFOTNASAL. In each step, arterial blood gases, respiratory rate, and tracheal pressure were measured.ResultsDuring HFOTTRACHEAL, PaO2/FiO2 ratio and tracheal expiratory pressure slightly increased proportionally to gas flow. The mean [95% confidence interval] expiratory pressure raise induced by 10-L/min increase in flow was 0.2 [0.1–0.2] cmH2O (ρ = 0.77, p < 0.001). Compared to standard oxygen, HFOTTRACHEAL limited the negative inspiratory swing in tracheal pressure; at 50 L/min, but not with other settings, HFOTTRACHEAL increased mean tracheal expiratory pressure by (mean difference [95% CI]) 0.4 [0.3–0.6] cmH2O, peak tracheal expiratory pressure by 0.4 [0.2–0.6] cmH2O, improved PaO2/FiO2 ratio by 40 [8–71] mmHg, and reduced respiratory rate by 1.9 [0.3–3.6] breaths/min without PaCO2 changes. As compared to HFOTTRACHEAL, HFOTNASAL produced higher tracheal mean and peak expiratory pressure (at 50 L/min, mean difference [95% CI]: 3 [1–5] cmH2O and 4 [1–7] cmH2O, respectively).ConclusionsAs compared to standard oxygen, 50 L/min of HFOTTRACHEAL are needed to improve oxygenation, reduce respiratory rate and provide small degree of positive airway expiratory pressure, which, however, is significantly lower than the one produced by HFOTNASAL.
Background: Driving pressure (DP) represents tidal volume normalised to respiratory system compliance (C RS) and is a novel parameter to target ventilator settings. We conducted a study to determine whether C RS and DP reflect aerated lung volume and dynamic strain during general anaesthesia. Methods: Twenty non-obese patients undergoing open abdominal surgery received three PEEP levels (2, 7, or 12 cm H 2 O) in random order with constant tidal volume ventilation. Respiratory mechanics, lung volumes, and alveolar recruitment were measured to assess end-expiratory aerated volume, which was compared with the patient's individual predicted functional residual capacity in supine position (FRCp). Results: C RS was linearly related to aerated volume and DP to dynamic strain at PEEP of 2 cm H 2 O (intraoperative FRC) (r¼0.72 and r¼0.73, both P<0.001). These relationships were maintained with higher PEEP only when aerated volume did not overcome FRCp (r¼0.73, P<0.001; r¼0.54, P¼0.004), with 100 ml lung volume increases accompanied by 1.8 ml cm H 2 O À1 (95% confidence interval [1.1e2.5]) increases in C RS. When aerated volume was greater or equal to FRCp (35% of patients at PEEP 2 cm H 2 O, 55% at PEEP 7 cm H 2 O, and 75% at PEEP 12 cm H 2 O), C RS and DP were independent from aerated volume and dynamic strain, with C RS weakly but significantly inversely related to alveolar dead space fraction (r¼e0.47, P¼0.001). PEEP-induced alveolar recruitment yielded higher C RS and reduced DP only at aerated volumes below FRCp (P¼0.015 and 0.008, respectively). Conclusions: During general anaesthesia, respiratory system compliance and driving pressure reflect aerated lung volume and dynamic strain, respectively, only if aerated volume does not exceed functional residual capacity in supine position, which is a frequent event when PEEP is used in this setting.
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