scholarly journals Reliability of mechanical ventilation during continuous chest compressions: a crossover study of transport ventilators in a human cadaver model of CPR

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Simon Orlob ◽  
Johannes Wittig ◽  
Christoph Hobisch ◽  
Daniel Auinger ◽  
Gabriel Honnef ◽  
...  
Keyword(s):  
Body Weight ◽  
Crossover Study ◽  
Tidal Volume ◽  
Linear Models ◽  
Mixed Linear Model ◽  
Alveolar Ventilation ◽  
Mixed Linear Models ◽  
Chest Compressions ◽  
Predicted Body Weight ◽  
Random Factor

Abstract Background Previous studies have stated that hyperventilation often occurs in cardiopulmonary resuscitation (CPR) mainly due to excessive ventilation frequencies, especially when a manual valve bag is used. Transport ventilators may provide mandatory ventilation with predetermined tidal volumes and without the risk of hyperventilation. Nonetheless, interactions between chest compressions and ventilations are likely to occur. We investigated whether transport ventilators can provide adequate alveolar ventilation during continuous chest compression in adult CPR. Methods A three-period crossover study with three common transport ventilators in a cadaver model of CPR was carried out. The three ventilators ‘MEDUMAT Standard²’, ‘Oxylog 3000 plus’, and ‘Monnal T60’ represent three different interventions, providing volume-controlled continuous mandatory ventilation (VC-CMV) via an endotracheal tube with a tidal volume of 6 mL/kg predicted body weight. Proximal airflow was measured, and the net tidal volume was derived for each respiratory cycle. The deviation from the predetermined tidal volume was calculated and analysed. Several mixed linear models were calculated with the cadaver as a random factor and ventilator, height, sex, crossover period and incremental number of each ventilation within the period as covariates to evaluate differences between ventilators. Results Overall median deviation of net tidal volume from predetermined tidal volume was − 21.2 % (IQR: 19.6, range: [− 87.9 %; 25.8 %]) corresponding to a tidal volume of 4.75 mL/kg predicted body weight (IQR: 1.2, range: [0.7; 7.6]). In a mixed linear model, the ventilator model, the crossover period, and the cadaver’s height were significant factors for decreased tidal volume. The estimated effects of tidal volume deviation for each ventilator were − 14.5 % [95 %-CI: −22.5; −6.5] (p = 0.0004) for ‘Monnal T60’, − 30.6 % [95 %-CI: −38.6; −22.6] (p < 0.0001) for ‘Oxylog 3000 plus’ and − 31.0 % [95 %-CI: −38.9; −23.0] (p < 0.0001) for ‘MEDUMAT Standard²’. Conclusions All investigated transport ventilators were able to provide alveolar ventilation even though chest compressions considerably decreased tidal volumes. Our results support the concept of using ventilators to avoid excessive ventilatory rates in CPR. This experimental study suggests that healthcare professionals should carefully monitor actual tidal volumes to recognise the occurrence of hypoventilation during continuous chest compressions.

Ventilation standards for small mammals

1964 ◽  
Vol 19 (2) ◽  
pp. 360-362 ◽  
Author(s):  
Leonard I. Kleinman ◽  
Edward P. Radford
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Small Mammals ◽  
Artificial Respiration ◽  
Alveolar Ventilation ◽  
Breathing Frequency ◽  
Slide Rule ◽  
Physiological Dead Space ◽  
The Relationship ◽  
Tidal Volume Breathing

Ventilation standards for small mammals have been prepared on the basis of the relationship between alveolar ventilation and metabolism. On the assumptions of an average respiratory quotient of 0.85 and physiological dead space directly proportional to tidal volume, the relationship between tidal volume, breathing frequency, and body weight has been derived. The standards are presented in a graphic form and as a slide rule. animal ventilation; artificial respiration; tidal volume, breathing frequency and body weight relationship Submitted on August 15, 1963

scholarly journals Assessment of Fluid Responsiveness After Tidal Volume Challenge During Pressure-Controlled Ventilation Volume Guaranteed: An observational study

2020 ◽  
Author(s):  
Yu Jiang ◽  
Lingling Jiang ◽  
Jun Hu ◽  
Ye Zhang
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Fluid Responsiveness ◽  
Transient Increase ◽  
Anesthesia Induction ◽  
Predicted Body Weight ◽  
Controlled Ventilation ◽  
Pressure Controlled Ventilation ◽  
Pressure Controlled ◽  
Volume Challenge

Abstract Background: The reliability of pulse pressure variation (PPV) and stroke volume variation (SVV) to predict fluid responsiveness have not previously been established when using pressure-controlled ventilation-volume guaranteed (PCV-VG) mode. We hypothesized that with a transient increase in tidal volume from 6 to 8 mL/kg of predicted body weight (PBW), which we reference as the “tidal volume challenge (TVC)”, the changes to PPV and SVV will be an indicator of fluid responsiveness.Methods: The patients were first ventilated with a tidal volume of (Vt) 6 mL/kg of predicted body weight (PBW) using PCV-VG. Following intravenous anesthesia induction, PPV6 and SVV6 were recorded, then the TVC was performed, which increased Vt from 6 mL/kg to 8 mL/kg PBW for 1 minute and PPV8 and SVV8 were recorded again. The changes in value of PPV and SVV (ΔPPV6-8 and ΔSVV6-8) were calculated after TVC. Following the minute of TVC, the tidal volume was returned to 6 ml/kg PBW for the fluid challenge (FC), a colloid infusion of 6ml/kg PBW for 20 minutes. Patients were classified as responders if there was an increase in cardiac index (CI) of more than 15% after FC, otherwise the patients were identified as non-responders. Eligible patients were divided into groups of responders or non-responders.Results: 37 patients were classified as responders and 44 were non-responders. PPV6 and SVV6 could not predict the fluid responsiveness, while PPV8 and SVV8 could predict the fluid responsiveness when using PCV-VG mode. The changes in value of PPV and SVV after TVC (ΔPPV6-8 and ΔSVV6-8) identified true fluid responders with the highest sensitivity and specificity in the above variables, which predicted fluid responsiveness with the area under the receiver operating characteristic curves (AUCs) (95% CIs) being 0.96 (0.93-1.00) and 0.98 (0.96-1.00), respectively. No significant difference was found when comparing the AUCs of ΔPPV6-8 and ΔSVV6-8 (P > 0.05). Linear correlation was represented between the change value of CI after FC and the change value of SVV or PPV after TVC (r = 0.68; P < 0.0001 and r = 0.77; P < 0.0001, respectively).Conclusions: A transient increase in tidal volume, which we reference as the “tidal volume challenge (TVC)” could enhance the predictive value of PPV and SVV for the evaluation of fluid responsiveness in patients under ventilation with PCV-VG.Trial registration: Chinese Clinical Trial Registry (ChiCTR2000028995). Prospectively registered on 11 January 2020. http://www.medresman.org.

Effects of Feedback and Education on Nurses’ Clinical Competence in Mechanical Ventilation and Accurate Tidal Volume Setting

2021 ◽  
Author(s):  
Samira Norouzrajabi ◽  
Shahrzad Ghiyasvandian ◽  
Alireza Jeddian ◽  
Ali Karimi Rozveh ◽  
Leila Sayadi
Keyword(s):  
Mechanical Ventilation ◽  
Body Weight ◽  
Tidal Volume ◽  
Clinical Competence ◽  
High Tidal Volume ◽  
Education Intervention ◽  
Predicted Body Weight ◽  
Post Test ◽  
The Mean ◽  
Effects Of Feedback

Background: Patients under mechanical ventilation are at risk of ventilator-associated complications. One of these complications is lung injury due to high tidal volume. Nurses’ competence in mechanical ventilation is critical for preventing ventilator-associated complications. This study assessed the effects of feedback and education on nurses’ clinical competence in mechanical ventilation and accurate tidal volume setting. Methods: This single arm pretest-post-test interventional study was conducted in 2019 at Shariati hospital affiliated to Tehran University of Medical Sciences. Participants were 75 conveniently selected nurses. Initially, nurses’ clinical competence in mechanical ventilation and ventilator parameters of 250 patients were assessed. A mechanical ventilation -based feedback and education intervention was implemented for nurses. Finally, mechanical ventilation clinical competence of nurses and ventilator parameters of 250 new patients were assessed. Moreover, patients’ height was estimated based on their ulna length and then, their predicted body weight was calculated using their estimated height. Accurate tidal volume was determined per predicted body weight.  Results: The mean score of nurses’ clinical competence increased from 8.27±3.09 at pretest to 10.07±3.34 at post-test (p<0.001). The mean values of both total tidal volume and tidal volume per kilogram of predicted body weight were significantly reduced respectively from 529.84±69.11 and 9.11±1.73 (ml) at pretest to 476.30±31.01 and 7.79±1.14 (ml) at post-test (p<0.001). Conclusion: The feedback and education intervention is effective in promoting nurses’ clinical competence in mechanical ventilation and reducing tidal volume. Thereby, it can reduce lung injuries associated with high tidal volume and ensure patient safety.

scholarly journals Effect of Immediately-After-Birth Weaning on the Development of Goat Kids Born to Small Ruminant Lentivirus-Positive Dams

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 822 ◽  
Author(s):  
Nalbert ◽  
Czopowicz ◽  
Szaluś-Jordanow ◽  
Moroz ◽  
Mickiewicz ◽  
...  
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Linear Models ◽  
Small Ruminant ◽  
Negative Impact ◽  
Body Weight Gain ◽  
Mixed Linear Models ◽  
Daily Body Weight ◽  
The Mean ◽  
The Difference

A longitudinal study was carried out to investigate the influence of two different rearing systems of young kids on their development to sexual maturity. Kids born to small ruminant lentiviruses-infected (SRLV) female goats were split into two groups: the immediately-after-birth weaned group and the unweaned group. Kids’ body weight (BWT) was measured before the first consumption of colostrum, and then at the age of one week, and one, two, four, and seven months. The relationship between the rearing system and BWT at each age was investigated using mixed linear models adjusted for potential confounders. The mean BWT of kids of the immediately-after-birth weaned group was significantly lower at the age of one week, one month, and two months, and then the difference became insignificant. The mean daily body weight gain (DWG) was significantly lower in the immediately-after-birth weaned group during the whole first month of life, but then DWG in both groups became equal. Crude mortality rate did not differ significantly between groups. This study shows that weaning kids immediately after birth does not appear to have any negative impact on kids’ development except transient growth retardation, which is fully compensated until they reach sexual maturity.

scholarly journals Tidal Volume, Predicted Body Weight, and Modes of Mechanical Ventilation

CHEST Journal ◽  
2016 ◽  
Vol 150 (4) ◽  
pp. 322A
Author(s):  
Keith Lamb ◽  
Trevor Oetting ◽  
Julie Jackson ◽  
Gregory Hicklin
Keyword(s):  
Mechanical Ventilation ◽  
Body Weight ◽  
Tidal Volume ◽  
Predicted Body Weight

scholarly journals High Tidal Volumes in Mechanically Ventilated Patients Increase Organ Dysfunction after Cardiac Surgery

2012 ◽  
Vol 116 (5) ◽  
pp. 1072-1082 ◽  
Author(s):  
François Lellouche ◽  
Stéphanie Dionne ◽  
Serge Simard ◽  
Jean Bussières ◽  
François Dagenais
Keyword(s):  
Risk Factors ◽  
Intensive Care Unit ◽  
Body Weight ◽  
Cardiac Surgery ◽  
Intensive Care ◽  
Lung Injury ◽  
Tidal Volume ◽  
Organ Failure ◽  
Predicted Body Weight ◽  
Prolonged Stay

Background High tidal volumes in patients with acute respiratory distress syndrome and acute lung injury lead to ventilator-induced lung injury and increased mortality. We evaluated the impact of tidal volumes on cardiac surgery outcomes. Methods We examined prospectively recorded data from 3,434 consecutive adult patients who underwent cardiac surgery. Three groups of patients were defined based on the tidal volume delivered on arrival at the intensive care unit: (1) low: below 10, (2) traditional: 10-12, and (3) high: more than 12 ml/kg of predicted body weight. We assessed risk factors for three types of organ failure (prolonged mechanical ventilation, hemodynamic instability, and renal failure) and a prolonged stay in the intensive care unit. Results The mean tidal volume/actual weight was 9.2 ml/kg, and the tidal volume/predicted body weight was 11.5 ml/kg. Low, traditional, and high tidal volumes were used in 724 (21.1%), 1567 (45.6%), and 1,143 patients (33.3%), respectively. Independent risks factors for high tidal volumes were body mass index of 30 or more (odds ratio [OR] 6.25; CI: 5.26-7.42; P &lt; 0.001) and female sex (OR 4.33; CI: 3.64-5.15; P &lt; 0.001). In the multivariate analysis, high and traditional tidal volumes were independent risk factors for organ failure, multiple organ failure, and prolonged stay in the intensive care unit. Organ failures were associated with increased intensive care unit stay, hospital mortality, and long-term mortality. Conclusion Tidal volumes of more than 10 ml/kg are risk factors for organ failure and prolonged intensive care unit stay after cardiac surgery. Women and obese patients are particularly at risk of being ventilated with injurious tidal volumes.

scholarly journals A Higher Tidal Volume May Be Used for Athletes according to Measured FVC

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Pavlos Myrianthefs ◽  
George Baltopoulos
Keyword(s):  
Mechanical Ventilation ◽  
Body Weight ◽  
Tidal Volume ◽  
Vital Capacity ◽  
Professional Athletes ◽  
Normal Lung ◽  
Predicted Body Weight ◽  
Lung Volumes ◽  
Males And Females ◽  
The Difference

We investigated whether professional athletes may require higher tidal volume (Tv) during mechanical ventilation hypothesizing that they have significantly higher “normal” lung volumes compared to what was predicted and to nonathletes. Measured and predicted spirometric values were recorded in both athletes and nonathletes using a Spirovit SP-1 spirometer (Schiller, Switzerland). NormalTv(6 mL/kg of predicted body weight) was calculated as a percentage of measured and predicted forced vital capacity (FVC) and the difference (δ) was used to calculate the additionalTvrequired using the equation: NewTv(TvN)=Tv+(Tv×δ). Professional athletes had significantly higher FVC compared to what was predicted (by 9% in females and 10% in males) and to nonathletes. They may also require aTvof 6.6 mL/kg for males and 6.5 mL/kg for females during mechanical ventilation. Nonathletes may require aTvof 5.8 ± 0.1 mL/kg and 6.3 ± 0.1 mL/kg for males and females, respectively. Our findings show that athletes may require additionalTvof 10% (0.6/6 mL/kg) for males and 8.3% (0.5/6 mL/kg) for females during general anesthesia and critical care which needs to be further investigated and tested.

scholarly journals Accurate Tidal Volume for Patients under Mechanical Ventilation: A Cross-sectional Descriptive Study

2020 ◽  
Author(s):  
Leila Sayadi ◽  
Shahrzad Ghiyasvandian ◽  
Ali Karimi Rozveh ◽  
Samira Norouzrajabi
Keyword(s):  
Mechanical Ventilation ◽  
Body Weight ◽  
Lung Injury ◽  
Tidal Volume ◽  
Improve Patient Safety ◽  
Descriptive Study ◽  
Predicted Body Weight ◽  
Volume Determination ◽  
Cross Sectional ◽  
Nurses Knowledge

Background: In order to prevent lung injury among patients under mechanical ventilation, tidal volume should be determined based on predicted body weight. The aim of the study was to determine the accuracy of tidal volume determination for patients under mechanical ventilation and to assess nurses’ knowledge about accurate tidal volume determination. Methods: This was a cross-sectional descriptive study. This study was conducted on 250 patients under mechanical ventilation and 75 nurses who provided care to the patients. Patients’ height was estimated based on their ulna length and then, their predicted body weight and tidal volume were estimated. Nurses’ knowledge about tidal volume determination was also assessed. Results: The mean of delivered tidal volume was 9.1±1.73 mL/kg of predicted body weight. Tidal volume for 172 patients (68.8%) had been set at more than 8 mL/kg of predicted body weight. Forty nine nurses (65.3%) noted that there was no guideline in their wards for height and weight measurement. They determined patients’ weight and height through either visual estimation (21 nurses; 28.0%) or asking from their colleagues, patients, or patients’ family members (48 nurses; 64.0%). Conclusion: Nurses have limited knowledge about accurate tidal volume determination and hence, deliver high tidal volume to patients under mechanical ventilation which puts them at risk for ventilator-associated lung injury. Urgent interventions such as lung-protective strategies, staff training, and careful managerial supervision are needed to prevent ventilator-associated lung injury and improve patient safety.

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