-
Critical Care (London, England) Jul 2020Mechanical power (MP) is the energy delivered to the respiratory system over time during mechanical ventilation. Our aim was to compare the currently available methods... (Observational Study)
Observational Study
BACKGROUND
Mechanical power (MP) is the energy delivered to the respiratory system over time during mechanical ventilation. Our aim was to compare the currently available methods to calculate MP during volume- and pressure-controlled ventilation, comparing different equations with the geometric reference method, to understand whether the easier to use surrogate formulas were suitable for the everyday clinical practice. This would warrant a more widespread use of mechanical power to promote lung protection.
METHODS
Forty respiratory failure patients, sedated and paralyzed for clinical reasons, were ventilated in volume-controlled ventilation, at two inspiratory flows (30 and 60 L/min), and pressure-controlled ventilation with a similar tidal volume. Mechanical power was computed both with the geometric method, as the area between the inspiratory limb of the airway pressure and the volume, and with two algebraic methods, a comprehensive and a surrogate formula.
RESULTS
The bias between the MP computed by the geometric method and by the comprehensive algebraic method during volume-controlled ventilation was respectively 0.053 (0.77, - 0.81) J/min and - 0.4 (0.70, - 1.50) J/min at low and high flows (r = 0.96 and 0.97, p < 0.01). The MP measured and computed by the two methods were highly correlated (r = 0.95 and 0.94, p < 0.01) with a bias of - 0.0074 (0.91, - 0.93) and - 1.0 (0.45, - 2.52) J/min at high-low flows. During pressure-controlled ventilation, the bias between the MP measured and the one calculated with the comprehensive and simplified methods was correlated (r = 0.81, 0.94, p < 0.01) with mean differences of - 0.001 (2.05, - 2.05) and - 0.81 (2.11, - 0.48) J/min.
CONCLUSIONS
Both for volume-controlled and pressure-controlled ventilation, the surrogate formulas approximate the reference method well enough to warrant their use in the everyday clinical practice. Given that these formulas require nothing more than the variables already displayed by the intensive care ventilator, a more widespread use of mechanical power should be encouraged to promote lung protection against ventilator-induced lung injury.
Topics: Female; Humans; Lung; Male; Mechanical Phenomena; Middle Aged; Pressure; Respiration, Artificial; Respiratory Insufficiency; Weights and Measures
PubMed: 32653011
DOI: 10.1186/s13054-020-03116-w -
Anesthesiology Mar 2023
Topics: Respiration, Artificial; Positive-Pressure Respiration; Lung
PubMed: 36749421
DOI: 10.1097/ALN.0000000000004489 -
Critical Care (London, England) Apr 2013Non-invasive mechanical ventilation (NIV) has proved to be an excellent technique in selected critically ill patients with different forms of acute respiratory failure.... (Review)
Review
Non-invasive mechanical ventilation (NIV) has proved to be an excellent technique in selected critically ill patients with different forms of acute respiratory failure. However, NIV can fail on account of the severity of the disease and technical problems, particularly at the interface. The helmet could be an alternative interface compared to face mask to improve NIV success. We performed a clinical review to investigate the main physiological and clinical studies assessing the efficacy and related issues of NIV delivered with a helmet. A computerized search strategy of MEDLINE/PubMed (January 2000 to May 2012) and EMBASE (January 2000 to May 2012) was conducted limiting the search to retrospective, prospective, nonrandomized and randomized trials. We analyzed 152 studies from which 33 were selected, 12 physiological and 21 clinical (879 patients). The physiological studies showed that NIV with helmet could predispose to CO₂ rebreathing and increase the patients' ventilator asynchrony. The main indications for NIV were acute cardiogenic pulmonary edema, hypoxemic acute respiratory failure (community-acquired pneumonia, postoperative and immunocompromised patients) and hypercapnic acute respiratory failure. In 9 of the 21 studies the helmet was compared to a face mask during either continous positive airway pressure or pressure support ventilation. In eight studies oxygenation was similar in the two groups, while the intubation rate was similar in four and lower in three studies for the helmet group compared to face mask group. The outcome was similar in six studies. The tolerance was better with the helmet in six of the studies. Although these data are limited, NIV delivered by helmet could be a safe alternative to the face mask in patients with acute respiratory failure.
Topics: Clinical Trials as Topic; Critical Illness; Head Protective Devices; Humans; Masks; Positive-Pressure Respiration; Prospective Studies; Respiration, Artificial; Respiratory Insufficiency; Retrospective Studies
PubMed: 23680299
DOI: 10.1186/cc11875 -
MMW Fortschritte Der Medizin Apr 2020
Topics: Home Care Services; Humans; Respiration, Artificial; Respiratory Insufficiency
PubMed: 32291697
DOI: 10.1007/s15006-020-0012-z -
Pharmacology Research & Perspectives Dec 2020At present, the efficacy and safety of dexmedetomidine in patients receiving mechanical ventilation (MV) is still controversial. Therefore, the purpose of this research... (Meta-Analysis)
Meta-Analysis Review
At present, the efficacy and safety of dexmedetomidine in patients receiving mechanical ventilation (MV) is still controversial. Therefore, the purpose of this research was to assess the efficacy and safety of dexmedetomidine in MV patients by reviewing the results of randomized controlled trials (RCT). RCTs evaluating the efficacy of dexmedetomidine in the treatment of MV patients were obtained by searching relevant online databases, including PubMed, EMbase, Web of Science, the Cochrane Library, Medline, OVID, and ClinicalTrials.gov. Literature meeting the inclusion criteria were selected and evaluated by two researchers independently. Risk ratio (RR)/standardized mean difference (SMD) and 95% confidence interval (CI) were used to express the differences between groups. Seven RCTs were included in our study, with 986 participants in the dexmedetomidine group and 862 participants in the control group. Summary analysis results displayed no reduction in 30-day mortality (RR = 0.77, 95% CI: 0.59 to 1.02), delirium (RR = 0.77, 95% CI: 0.57 to 1.03), and adverse events (RR = 1.06, 95% CI: 0.22 to 5.08) in the dexmedetomidine group compared with the control group. As the length of stay in the intensive care unit (ICU) were presented as median and interquartile range (IQR)/standard deviation (SD), descriptive analysis of the results were performed. Generally, for 99.65% (953/986) of patients, dexmedetomidine was not better than the control group in reducing ICU length of stay. Our results demonstrate that for patients requiring MV, dexmedetomidine was not superior to the control group. However, analysis of more RCTs is required to confirm this conclusion.
Topics: Analgesics, Non-Narcotic; Dexmedetomidine; Humans; Mortality; Randomized Controlled Trials as Topic; Respiration, Artificial
PubMed: 33179456
DOI: 10.1002/prp2.658 -
Minerva Anestesiologica Apr 2017
Topics: Airway Extubation; Humans; Intensive Care Units; Respiration, Artificial; Terminal Care; Ventilator Weaning
PubMed: 28206736
DOI: 10.23736/S0375-9393.17.11951-6 -
Respiratory Care Jun 2016Intermittent mandatory ventilation (IMV) was introduced nearly 50 years ago. Despite the initial fanfare and early adoption by many, the role of IMV continues to be... (Review)
Review
Intermittent mandatory ventilation (IMV) was introduced nearly 50 years ago. Despite the initial fanfare and early adoption by many, the role of IMV continues to be questioned. The use of small tidal volumes complicates the application of IMV, and issues with work of breathing, weaning and lack of clear advantages have many calling for a moratorium on its use. Spontaneous breathing, however, has a number of salutatory effects on gas exchange, the distribution of ventilation, and hemodynamics. These issues will be explored in light of a growing body of evidence.
Topics: Animals; Humans; Intermittent Positive-Pressure Ventilation; Lung; Respiration; Respiration, Artificial
PubMed: 27235318
DOI: 10.4187/respcare.04887 -
Respiratory Care Apr 2015Home mechanical ventilation (HMV) is a routine method of treatment for patients with chronic ventilatory failure. Over the last 20 y, a marked development in HMV has...
BACKGROUND
Home mechanical ventilation (HMV) is a routine method of treatment for patients with chronic ventilatory failure. Over the last 20 y, a marked development in HMV has been noted in terms of its prevalence and the changing proportion of patients with various indications. However, data on HMV come exclusively from the developed countries of Europe and North America. Nowadays, we can see the emergence of HMV in less developed countries. This study aimed to describe the development of HMV in Poland.
METHODS
Data from the largest HMV centers were retrospectively evaluated with regard to cause of respiratory failure, ventilation technique, and characteristics of the HMV-implementing institution.
RESULTS
The number of subjects treated with HMV increased from 8 in 2000 to 928 in 2010. Neuromuscular diseases remained the main indication. However, their relative contribution decreased from 100 to 51% in favor of pulmonary diseases (an increase from 0 to 21%) and hypoventilation syndromes (0% in 2000 and 11% in 2010). The majority of the HMV population treated between 2000 between 2008 was ventilated by tracheostomy; however, since 2007, the percentage of subjects on noninvasive ventilation significantly increased and was equal to the number of tracheostomized subjects. HMV was initiated mainly in ICUs. However, their role systematically diminished, and an increasing number of subjects were recruited in respiratory departments.
CONCLUSIONS
The prescription pattern of HMV in Poland has evolved, and there is a clear shift from neuromuscular to respiratory diseases. The prevalence of ventilation via tracheostomy still remains very high in comparison with other European countries. The Polish experience could be useful for countries with emerging HMV care systems.
Topics: Adolescent; Adult; Child; Home Care Services; Humans; Lung Diseases; Neuromuscular Diseases; Poland; Prevalence; Respiration, Artificial; Respiratory Insufficiency; Retrospective Studies; Tracheostomy
PubMed: 25492950
DOI: 10.4187/respcare.03126 -
Critical Care (London, England) Jun 2016Acute respiratory distress syndrome (ARDS) is characterized by a noncardiogenic pulmonary edema with bilateral chest X-ray opacities and reduction in lung compliance,... (Review)
Review
BACKGROUND
Acute respiratory distress syndrome (ARDS) is characterized by a noncardiogenic pulmonary edema with bilateral chest X-ray opacities and reduction in lung compliance, and the hallmark of the syndrome is hypoxemia refractory to oxygen therapy. Severe hypoxemia (PaO2/FiO2 < 100 mmHg), which defines severe ARDS, can be found in 20-30 % of the patients and is associated with the highest mortality rate. Although the standard supportive treatment remains mechanical ventilation (noninvasive and invasive), possible adjuvant therapies can be considered. We performed an up-to-date clinical review of the possible available strategies for ARDS patients with severe hypoxemia.
MAIN RESULTS
In summary, in moderate-to-severe ARDS or in the presence of other organ failure, noninvasive ventilatory support presents a high risk of failure: in those cases the risk/benefit of delayed mechanical ventilation should be evaluated carefully. Tailoring mechanical ventilation to the individual patient is fundamental to reduce the risk of ventilation-induced lung injury (VILI): it is mandatory to apply a low tidal volume, while the optimal level of positive end-expiratory pressure should be selected after a stratification of the severity of the disease, also taking into account lung recruitability; monitoring transpulmonary pressure or airway driving pressure can help to avoid lung overstress. Targeting oxygenation of 88-92 % and tolerating a moderate level of hypercapnia are a safe choice. Neuromuscular blocking agents (NMBAs) are useful to maintain patient-ventilation synchrony in the first hours; prone positioning improves oxygenation in most cases and promotes a more homogeneous distribution of ventilation, reducing the risk of VILI; both treatments, also in combination, are associated with an improvement in outcome if applied in the acute phase in the most severe cases. The use of extracorporeal membrane oxygenation (ECMO) in severe ARDS is increasing worldwide, but because of a lack of randomized trials is still considered a rescue therapy.
CONCLUSION
Severe ARDS patients should receive a holistic framework of respiratory and hemodynamic support aimed to ensure adequate gas exchange while minimizing the risk of VILI, by promoting lung recruitment and setting protective mechanical ventilation. In the most severe cases, NMBAs, prone positioning, and ECMO should be considered.
Topics: Extracorporeal Membrane Oxygenation; Humans; Hypoxia; Respiration, Artificial; Respiratory Distress Syndrome; Tidal Volume; Ventilator-Induced Lung Injury
PubMed: 27255913
DOI: 10.1186/s13054-016-1304-7 -
Respiratory Care Apr 2015Mechanical ventilation is an important and ever-evolving component of everyday critical care. Clinicians can struggle to keep up with current literature and descriptions... (Review)
Review
Mechanical ventilation is an important and ever-evolving component of everyday critical care. Clinicians can struggle to keep up with current literature and descriptions of advancement in a way that they can apply these changes to their bedside patient care. This article serves as a review of important recent findings related to invasive mechanical ventilation and describes their relevance to bedside critical care.
Topics: Critical Care; Humans; Respiration, Artificial; Respiratory Insufficiency
PubMed: 25784772
DOI: 10.4187/respcare.04112