scholarly journals Does a Starting Positive End-Expiratory Pressure of 8 cm H2O Decrease the Probability of a Ventilator-Associated Event?

2021 ◽  
Vol 1 (S1) ◽  
pp. s80-s80
Author(s):  
William Barnett ◽  
Zachary Holtzapple ◽  
Ragheb Assaly
Keyword(s):  
Mechanical Ventilation ◽  
Positive End Expiratory Pressure ◽  
Probability Limit ◽  
Mechanically Ventilated ◽  
Event Probability ◽  
Critical Ill Patients ◽  
Wide Range ◽  
Neurosurgical Patients ◽  
Control And Prevention ◽  
Associated Conditions

Background: Mechanical ventilation is commonly seen in critical ill patients. The vulnerability of these patients is high, and a wide range of associated conditions can stem from this intervention. To objectively identify nosocomial respiratory conditions and provide conformed surveillance definitions of these events, the Centers for Disease Control and Prevention (CDC) established the ventilator-associated event (VAE) criteria. They denote 3 categories of increasing progression in mechanically ventilated patients from a ventilator-associated condition (VAC) to an infection-related ventilator-associated complication (IVAC) and finally to a possible ventilator-associated pneumonia (PVAP). Manipulation of ventilator settings, such as starting on higher values to not trigger VAC criteria, has been criticized by some experts as not only ‘gaming the system,’ but potentially harming patients. In October 2018, our institution began a baseline of 8 cm H2O as the starting positive end-expiratory pressure (PEEP) protocol for mechanical ventilation but exempting neurosurgical patients. We sought to determine whether an 8 PEEP protocol is an effective strategy for reducing VAEs in our institution. Methods: We retrospectively examined patient data at our institution from January 2014 through February 2020. VAEs were separated by VAC only and IVAC positive (+), which are a combination of IVACs and PVAPs. Using the days between VAEs, a daily event probability can be calculated based on the geometric distribution. Furthermore, as VAEs occur, the likelihood of the event can be assessed as expected or unexpected using a strict probability limit of 0.99865 to reduce type 1 errors. Results: In total, 307 patients were identified in our hospital’s VAE surveillance. Of those, 180 met CDC-defined VAC-only criteria, and 127 patients met IVAC+ definitions. After implementation of an 8-PEEP protocol, the daily event probability for VACs decreased from 0.083 to 0.047. The last event occurred 162 days after the previous VAC, which was unexpected, because the probability of occurrence extended beyond the probability limit. With regard to IVAC+ events, the daily event probability decreased from 0.057 to 0.039 without significant reduction in the IVAC+ rate. Conclusions: Although a change in the VAC-only rate occurred, signified by a longer time between events, it took more than a year to achieve in our institution. Additionally, we did not see a reduction in the IVAC+ rate. These findings suggest that an 8-PEEP protocol may be able to reduce VAEs due to noninfectious etiologies, such as congestive heart failure and atelectasis.Funding: NoDisclosure: None

Auto-PEEP: An Impediment to Weaning in the Chronically Ventilated Patient

1991 ◽  
Vol 2 (3) ◽  
pp. 391-397
Author(s):  
Lori Kohles Geisman ◽  
Tom Ahrens
Keyword(s):  
Mechanical Ventilation ◽  
Positive Pressure ◽  
Mechanical Ventilator ◽  
Weaning From Mechanical Ventilation ◽  
Positive End Expiratory Pressure ◽  
Potential Reduction ◽  
Mechanically Ventilated ◽  
Subsequent Elimination ◽  
Ventilator Settings ◽  
Ventilated Patients

Auto-positive end expiratory pressure (auto-PEEP) is a physiologic event that is a recently recognized phenomenon common to mechanically ventilated patients. Auto-PEEP occurs when forces exist that limit expiration and the subsequent elimination of positive pressure from the lungs. If positive pressure is retained, a potential reduction in cardiac output and increase in complications from barotrauma arise. Because of possible physiologic problems associated with it, auto-PEEP can potentially interfere with weaning from mechanical ventilation. Nursing measures that can reduce the effect of auto-PEEP during weaning are centered on improving the inspiratory/expiratory flow patterns. These efforts include manipulating mechanical ventilator settings and reducing causes of increased respiratory rates (e.g., pain and anxiety). Since auto-PEEP was only recently identified as a potential impediment to weaning from mechanical ventilation, the nurse must be aware of the need to assess for the presence of auto-PEEP in these patients

The Clinical Impact of Ventilator-Associated Events: A Prospective Multi-Center Surveillance Study

2015 ◽  
Vol 36 (12) ◽  
pp. 1388-1395 ◽  
Author(s):  
Shichao Zhu ◽  
Lin Cai ◽  
Chunhua Ma ◽  
Hongmei Zeng ◽  
Hua Guo ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Intensive Care ◽  
Mortality Rate ◽  
Mortality Rates ◽  
Clinical Impact ◽  
Surveillance Study ◽  
Ventilator Associated Pneumonia ◽  
Icu Length Of Stay ◽  
Control And Prevention ◽  
Associated Conditions

OBJECTIVEThe Centers for Disease Control and Prevention (CDC) has developed an approach to ventilator-associated events (VAE) surveillance. Using these methods, this study was performed to investigate VAE incidences and to test whether VAEs are associated with poorer outcomes in China.DESIGNA 4-month, prospective multicenter surveillance study between April and July 2013.SETTINGOur study included 15 adult intensive care units (ICUs) of 15 hospitals in China.PATIENTSPatients admitted to ICUs during the study periodMETHODSPatients on mechanical ventilation (MV) were monitored for VAEs: ventilator-associated conditions (VACs), infection-related ventilator-associated complications (IVACs), and possible or probable ventilator-associated pneumonia (VAP). Patients with and without VACs were compared with regard to duration of MV, ICU length of stay (LOS), overall hospital LOS, and mortality rate.RESULTSDuring the study period, 2,356 of the 5,256 patients admitted to ICUs received MV for 8,438 ventilator days. Of these patients, 636 were on MV >2 days. VACs were identified in 94 cases (4.0%; 11.1 cases per 1,000 ventilator days), including 31 patients with IVACs and 16 with possible VAP but none with probable VAP. Compared with patients without VACs, patients with VACs had longer ICU LOS (by 6.2 days), longer duration on MV (by 7.7 days), and higher hospital mortality rate (50.0% vs 27.3%). The mortality rate attributable to VACs was 11.7%. Compared with those with VACs alone, patients with IVACs had longer duration on MV and increased ICU LOS but no higher mortality rates.CONCLUSIONSIn China, surveillance of VACs and IVACs is able to identify MV patients with poorer outcomes. However, surveillance of possible and probable VAP can be problematic.Infect. Control Hosp. Epidemiol. 2015;36(12):1388–1395

scholarly journals Nasal acquisition of Staphylococcus aureus in a subdivided and mechanically ventilated ward: endemic prevalence of a single staphylococcal strain

1970 ◽  
Vol 68 (3) ◽  
pp. 417-433 ◽  
Author(s):  
O. M. Lidwell ◽  
Sheila Polakoff ◽  
J. Davies ◽  
J. H. Hewitt ◽  
R. A. Shooter ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mechanical Ventilation ◽  
Nasal Carriage ◽  
The Other ◽  
Degree Of Contamination ◽  
Wound Sepsis ◽  
Single Strain ◽  
Mechanically Ventilated ◽  
Nasal Carrier ◽  
Wide Range

SUMMARYAn investigation was made of nasal acquisition of Staphylococcus aureus and of staphylococcal wound sepsis in a hospital ward divided into two sections and provided with mechanical ventilation, so that there was no transfer of air from one of the sections to the other. Although the strains of S. aureus found in the air, and those colonizing the noses of patients, in the protected section could seldom be related to patients nursed elsewhere in the ward, the mechanical ventilation did not lead to any significant reduction in the degree of contamination of the air or in the rate of nasal acquisition of S. aureus.Even in the protected section, nearly 20 % of the strains of S. aureus recovered from the air could not be related to known nasal carriers. Since this proportion was nearly as great as that found in the absence of directed air-flow, it seems probable that these strains were derived either from undetected sources within the section or were dispersed from the clothes of persons who entered it.Nearly one-third of the nasal acquisitions in the ward could not be related to known nasal carriers, but about one-half of these (16 %) were probably ‘spurious’ and half of the remainder (8 %) could be related to strains recovered from patients' lesions or drawsheets, leaving no more than 8% unaccounted for. A short investigation in which both drawsheet and perineal samples were examined showed that drawsheet samples did not give a reliable indication of perineal carriage unassociated with nasal carriage.During the period of the investigation, a single strain of S. aureus that was resistant to a wide range of antibiotics established itself in the ward. The most notable character of this strain was the profuse dispersion of it by carriers. As a consequence, staphylococcal wound sepsis increased, with nearly three-quarters of the infections attributable to this strain, and nasal carrier rates increased with length of stay in the ward, over 20 % of patients who stayed 5–6 weeks acquiring the strain.

scholarly journals Predicting physiologic response to changes in positive end-expiratory pressure in mechanically ventilated children: a computable phenotype and machine learning approach

2020 ◽  
Author(s):  
Craig D Smallwood ◽  
Andrew Gouldstone ◽  
John H Arnold
Keyword(s):  
Intensive Care Unit ◽  
Mechanical Ventilation ◽  
Time Series ◽  
Intensive Care ◽  
Diagnostic Accuracy ◽  
Series Data ◽  
Support Vector ◽  
Positive End Expiratory Pressure ◽  
Mechanically Ventilated ◽  
Physiologic Data

Abstract Background Positive end-expiratory pressure (PEEP) is often increased to improve ventilation efficiency and gas exchange during pediatric mechanical ventilation. Although it is clinically important to optimize PEEP in this population, there is a paucity of literature to guide the clinician at the bedside. Increasingly, time-series physiologic data are available for mechanically ventilated subjects in the intensive care unit. However, these data have not been adequately explored in the literature. Therefore, we sought to apply time-series computable phenotyping on time-series physiologic data and develop a model to predict PEEP response in mechanically ventilated children. Methods We conducted a retrospective analysis of continuous data in a academic hospital multidisciplinary intensive care unit. Patients were elgible for inclusion in the study if they received mechanically ventilation for > 25 hours and were < 18 years of age. Time-series data from the patient monitor and mechanical ventilator were abstracted 1-hour preceding and 1-hour following a PEEP change. PEEP increase (PEEPincrease), a responderwas defined as anyone who exhibited an improved dead-space fraction (Vd/Vt); non-respondersdemonstrated a worsening Vd/Vtin the hour following the PEEP change. Features from continuous mechanical ventilation variables were extracted and used to train a support vector machine model in order to predict Vd/Vt response to changes in PEEP. The performance of the model was assessed by calculating the area under the receiver operator characteristic curve (AUROC) and computing measures of diagnostic accuracy. Results In all, 393 PEEP change cases were included in the analysis in 83 subjects. A total of 27 computable phenotypes were identified and incorporated into the model. The AUROC was 0.82 and 0.90 for classifying response to PEEP increases and decreases respectively. The overall diagnostic accuracy was 0.75 for PEEP increases and 0.84 for PEEP decreases. Conclusions The model classified responders to increases and decreases in PEEP with reasonable accuracy. The model performed better for those cases when PEEP was decreases. In the future, these methods may play an important role in optimizing care of the mechanically ventilated pediatric patients, especially if they can be tailored to individual institutions.

scholarly journals Inspiratory Efforts, Positive End-Expiratory Pressure, and External Resistances Influence Intraparenchymal Gas Redistribution in Mechanically Ventilated Injured Lungs

2021 ◽  
Vol 11 ◽  
Author(s):  
Mariangela Pellegrini ◽  
Göran Hedenstierna ◽  
Anders Sune Larsson ◽  
Gaetano Perchiazzi
Keyword(s):  
Mechanical Ventilation ◽  
Spontaneous Breathing ◽  
Distress Syndrome ◽  
Inspiratory Flow ◽  
High Peep ◽  
Swine Model ◽  
Positive End Expiratory Pressure ◽  
Mechanically Ventilated ◽  
Airway Opening ◽  
Controlled Mechanical Ventilation

BackgroundPotentially harmful lung overstretch can follow intraparenchymal gas redistribution during mechanical ventilation. We hypothesized that inspiratory efforts characterizing spontaneous breathing, positive end-expiratory pressure (PEEP), and high inspiratory resistances influence inspiratory intraparenchymal gas redistribution.MethodsThis was an experimental study conducted on a swine model of mild acute respiratory distress syndrome. Dynamic computed tomography and respiratory mechanics were simultaneously acquired at different PEEP levels and external resistances, during both spontaneous breathing and controlled mechanical ventilation. Images were collected at two cranial–caudal levels. Delta-volume images (ΔVOLs) were obtained subtracting pairs of consecutive inspiratory images. The first three ΔVOLs, acquired for each analyzed breath, were used for the analysis of inspiratory pendelluft defined as intraparenchymal gas redistribution before the start of inspiratory flow at the airway opening. The following ΔVOLs were used for the analysis of gas redistribution during ongoing inspiratory flow at the airway opening.ResultsDuring the first flow-independent phase of inspiration, the pendelluft of gas was observed only during spontaneous breathing and along the cranial-to-caudal and nondependent-to-dependent directions. The pendelluft was reduced by high PEEP (p &lt; 0.04 comparing PEEP 15 and PEEP 0 cm H2O) and low external resistances (p &lt; 0.04 comparing high and low external resistance). During the flow-dependent phase of inspiration, two patterns were identified: (1) gas displacing characterized by large gas redistribution areas; (2) gas scattering characterized by small, numerous areas of gas redistribution. Gas displacing was observed at low PEEP, high external resistances, and it characterized controlled mechanical ventilation (p &lt; 0.01, comparing high and low PEEP during controlled mechanical ventilation).ConclusionsLow PEEP and high external resistances favored inspiratory pendelluft. During the flow-dependent phase of the inspiration, controlled mechanical ventilation and low PEEP and high external resistances favored larger phenomena of intraparenchymal gas redistribution (gas displacing) endangering lung stability.

scholarly journals Regional Lung Derecruitment and Inflammation during 16 Hours of Mechanical Ventilation in Supine Healthy Sheep

2013 ◽  
Vol 119 (1) ◽  
pp. 156-165 ◽  
Author(s):  
Mauro R. Tucci ◽  
Eduardo L. V. Costa ◽  
Tyler J. Wellman ◽  
Guido Musch ◽  
Tilo Winkler ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Regions Of Interest ◽  
Positive End Expiratory Pressure ◽  
18F Fluorodeoxyglucose ◽  
Positron Emission ◽  
Lung Dysfunction ◽  
Regional Lung ◽  
Net Uptake ◽  
Normal Lungs

Abstract Background: Lung derecruitment is common during general anesthesia. Mechanical ventilation with physiological tidal volumes could magnify derecruitment, and produce lung dysfunction and inflammation. The authors used positron emission tomography to study the process of derecruitment in normal lungs ventilated for 16 h and the corresponding changes in regional lung perfusion and inflammation. Methods: Six anesthetized supine sheep were ventilated with VT = 8 ml/kg and positive end-expiratory pressure = 0. Transmission scans were performed at 2-h intervals to assess regional aeration. Emission scans were acquired at baseline and after 16 h for the following tracers: (1) 18F-fluorodeoxyglucose to evaluate lung inflammation and (2) 13NN to calculate regional perfusion and shunt fraction. Results: Gas fraction decreased from baseline to 16 h in dorsal (0.31 ± 0.13 to 0.14 ± 0.12, P &lt; 0.01), but not in ventral regions (0.61 ± 0.03 to 0.63 ± 0.07, P = nonsignificant), with time constants of 1.5–44.6 h. Although the vertical distribution of relative perfusion did not change from baseline to 16 h, shunt increased in dorsal regions (0.34 ± 0.23 to 0.63 ± 0.35, P &lt; 0.01). The average pulmonary net 18F-fluorodeoxyglucose uptake rate in six regions of interest along the ventral–dorsal direction increased from 3.4 ± 1.4 at baseline to 4.1 ± 1.5⋅10−3/min after 16 h (P &lt; 0.01), and the corresponding average regions of interest 18F-fluorodeoxyglucose phosphorylation rate increased from 2.0 ± 0.2 to 2.5 ± 0.2⋅10−2/min (P &lt; 0.01). Conclusions: When normal lungs are mechanically ventilated without positive end-expiratory pressure, loss of aeration occurs continuously for several hours and is preferentially localized to dorsal regions. Progressive lung derecruitment was associated with increased regional shunt, implying an insufficient hypoxic pulmonary vasoconstriction. The increased pulmonary net uptake and phosphorylation rates of 18F-fluorodeoxyglucose suggest an incipient inflammation in these initially normal lungs.

scholarly journals Information and information resources in COVID-19: Awareness, control, and prevention

2021 ◽  
pp. 096100062110165
Author(s):  
Mohammadhiwa Abdekhoda ◽  
Fatemeh Ranjbaran ◽  
Asghar Sattari
Keyword(s):  
Low Cost ◽  
Information Resources ◽  
Age And Gender ◽  
Use Of Resources ◽  
Strategic Approach ◽  
Wide Range ◽  
Data Collection Instrument ◽  
Control And Prevention ◽  
And Gender ◽  
And Control

This study was conducted with the aim of evaluating the role of information and information resources in the awareness, control, and prevention of COVID-19. This study was a descriptive-analytical survey in which 450 participants were selected for the study. The data collection instrument was a researcher-made questionnaire. Descriptive and inferential statistics were used to analyze the data through SPSS. The findings show that a wide range of mass media has become well known as information resources for COVID-19. Other findings indicate a significant statistical difference in the rate of using information resources during COVID-19 based on age and gender; however, this difference is not significant regarding the reliability of information resources with regard to age and gender. Health information has an undisputable role in the prevention and control of pandemic diseases such as COVID-19. Providing accurate, reliable, and evidence-based information in a timely manner for the use of resources and information channels related to COVID-19 can be a fast and low-cost strategic approach in confronting this disease.

scholarly journals Management of Intraoperative Mechanical Ventilation to Prevent Postoperative Complications after General Anesthesia: A Narrative Review

2021 ◽  
Vol 10 (12) ◽  
pp. 2656
Author(s):  
Alberto Fogagnolo ◽  
Federica Montanaro ◽  
Lou’i Al-Husinat ◽  
Cecilia Turrini ◽  
Michela Rauseo ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Tidal Volume ◽  
Pulmonary Complications ◽  
Point Of View ◽  
Whole Body ◽  
Positive End Expiratory Pressure ◽  
Ventilation Strategies ◽  
Harmful Effects ◽  
Ventilation Induced Lung Injury ◽  
Different Levels

Mechanical ventilation (MV) is still necessary in many surgical procedures; nonetheless, intraoperative MV is not free from harmful effects. Protective ventilation strategies, which include the combination of low tidal volume and adequate positive end expiratory pressure (PEEP) levels, are usually adopted to minimize the ventilation-induced lung injury and to avoid post-operative pulmonary complications (PPCs). Even so, volutrauma and atelectrauma may co-exist at different levels of tidal volume and PEEP, and therefore, the physiological response to the MV settings should be monitored in each patient. A personalized perioperative approach is gaining relevance in the field of intraoperative MV; in particular, many efforts have been made to individualize PEEP, giving more emphasis on physiological and functional status to the whole body. In this review, we summarized the latest findings about the optimization of PEEP and intraoperative MV in different surgical settings. Starting from a physiological point of view, we described how to approach the individualized MV and monitor the effects of MV on lung function.

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