Another step for noninvasive ventilation in chronic obstructive pulmonary disease patients!

The use of noninvasive positive pressure ventilation (NPPV) in chronic obstructive pulmonary disease (COPD) patients who are not eligible for the technique because of their incapability to spontaneously eliminate accumulated secretions associated with hypercapnic encephalopathy is not recommended and is often considered a contraindication. In a case-control study, an experienced team reported the feasibility and safety of the use of NPPV with early fibreoptic bronchoscopy in selected acutely decompensated COPD patients with hypercapnic encephalopathy, and reported the patients' inability to spontaneously clear copious secretions. The reported data suggest that this innovative therapeutic may be considered as a potential alternative to endotracheal intubation

Clinical review: Ventilator-induced diaphragmatic dysfunction - human studies confirm animal model findings!

Diaphragmatic function is a major determinant of the ability to successfully wean patients from mechanical ventilation. However, the use of controlled mechanical ventilation in animal models results in a major reduction of diaphragmatic force-generating capacity together with structural injury and atrophy of diaphragm muscle fibers, a condition termed ventilator-induced diaphragmatic dysfunction (VIDD). Increased oxidative stress and exaggerated proteolysis in the diaphragm have been linked to the development of VIDD in animal models, but much less is known about the extent to which these phenomena occur in humans undergoing mechanical ventilation in the ICU. In the present review, we first briefly summarize the large body of evidence demonstrating the existence of VIDD in animal models, and outline the major cellular mechanisms that have been implicated in this process. We then relate these findings to very recently published data in critically ill patients, which have thus far been found to exhibit a remarkable degree of similarity with the animal model data. Hence, the human studies to date have indicated that mechanical ventilation is associated with increased oxidative stress, atrophy, and injury of diaphragmatic muscle fibers along with a rapid loss of diaphragmatic force production. These changes are, to a large extent, directly proportional to the duration of mechanical ventilation. In the context of these human data, we also review the methods that can be used in the clinical setting to diagnose and/or monitor the development of VIDD in critically ill patients. Finally, we discuss the potential for using different mechanical ventilation strategies and pharmacological approaches to prevent and/or to treat VIDD and suggest promising avenues for future research in this area

Combining high-flow nasal cannula oxygen and non-invasive ventilation for pre-oxygenation in the critically ill: is a double-pronged approach warranted?

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Sodium bicarbonate for severe metabolic acidaemia – Authors' reply

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Symmetrical and Anti-Symmetrical Buckling of Long Corroded Cylindrical Shell Subjected to External Pressure

This paper derives an exact analytical solution for determining elastic critical buckling pressures and mode shapes for very long corroded cylindrical steel shells subjected to external pressure considering symmetrical and anti-symmetrical mode cases. The corroded long cylindrical shell has been modelled as a non-uniform “stepped-type” ring consisting of two portions- corroded and un-corroded regions. A full range parametric study has been made to investigate the effect of corrosion angular extent and corrosion thickness on the elastic buckling pressures and their modes. The study shows that buckling loads and modes depend on the corrosion angular extent â and the corroded to un-corroded thicknesses ratio. The results are verified by a set of investigations with a series of corroded cylindrical shells. They showed a close agreement with those obtained from using the finite element package ABAQUS

Psychometric comparison of three behavioural scales for the assessment of pain in critically ill patients unable to self-report

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Procalcitonin biomarker kinetics fails to predict treatment response in perioperative abdominal infection with septic shock

International audienceIntroduction: Procalcitonin (PCT) biomarker is suggested to tailor antibiotic therapy in the medical intensive care unit (ICU) but studies in perioperative medicine are scarce. The aim of this study was to determine whether PCT reported thresholds are associated with the initial treatment response in perioperative septic shock secondary to intra-abdominal infection. Methods: This single ICU, observational study included patients with perioperative septic shocks secondary to intra-abdominal infection. Demographics, PCT at days 0, 1, 3, 5, treatment response and outcome were collected. Treatment failure included death related to the initial infection, second source control treatment or a new onset intra-abdominal infection. The primary endpoint was to assess whether PCT thresholds (0.5 ng/ml or a drop from the peak of at least 80%) predict the initial treatment response. Results: We included 101 consecutive cases. Initial treatment failed in 36 patients with a subsequent mortality of 75%. Upon admission, PCT was doubled when treatment ultimately failed (21.7 ng/ml +/- 38.7 vs. 41.7 ng/ml +/- 75.7; P = 0.04). Although 95% of the patients in whom PCT dropped down below 0.5 ng/ml responded to treatment, 50% of the patients in whom PCT remained above 0.5 ng/ml also responded successfully to treatment. Moreover, despite a PCT drop of at least 80%, 40% of patients had treatment failure. Conclusions: In perioperative intra-abdominal infections with shock, PCT decrease to 0.5 ng/ml lacked sensitivity to predict treatment response and its decrease of at least 80% from its peak failed to accurately predict treatment response. Studies in perioperative severe infections are needed before using PCT to tailor antibiotic use in this population

Positive end-expiratory pressure affects the value of intra-abdominal pressure in acute lung injury/acute respiratory distress syndrome patients: a pilot study

International audienceIntroduction: To examine the effects of positive end-expiratory pressure (PEEP) on intra-abdominal pressure (IAP) in patients with acute lung injury (ALI).Methods: Thirty sedated and mechanically ventilated patients with ALI or acute respiratory distress syndrome (ARDS) admitted to a sixteen-bed surgical medical ICU were included. All patients were studied with sequentially increasing PEEP (0, 6 and 12 cmH2O) during a PEEP-trial.Results: Age was 55 ± 17 years, weight was 70 ± 17 kg, SAPS II was 44 ± 14 and PaO2/FIO2 was 192 ± 53 mmHg. The IAP was 12 ± 5 mmHg at PEEP 0 (zero end-expiratory pressure, ZEEP), 13 ± 5 mmHg at PEEP 6 and 15 ± 6 mmHg at PEEP 12 (P < 0.05 vs ZEEP). In the patients with intra-abdominal hypertension defined as IAP ≥ 12 mmHg (n = 15), IAP significantly increased from 15 ± 3 mmHg at ZEEP to 20 ± 3 mmHg at PEEP 12 (P < 0.01). Whereas in the patients with IAP < 12 mmHg (n = 15), IAP did not significantly change from ZEEP to PEEP 12(8 ± 2 vs 10 ± 3 mmHg). In the 13 patients in whom cardiac output was measured, increase in PEEP from 0 to 12 cmH2O did not significantly change cardiac output, nor in the 8 out of 15 patients of the high-IAP group. The observed effects were similar in both ALI (n = 17) and ARDS (n = 13) patients.Conclusions: PEEP is a contributing factor that impacts IAP values. It seems necessary to take into account the level of PEEP whilst interpreting IAP values in patients under mechanical ventilation

Spontaneous breathing trial and post-extubation work of breathing in morbidly obese critically ill patients

Figure S5. difference in the work of breathing expressed in J/l between each test and the post-extubation period. Dashed line represents the absence of difference between the test and the post-extubation period. (JPG 44 kb