scholarly journals A Protective Tidal Volume Adapted To Lung Compliance and The PEEP Level With Lowest Transpulmonary Driving Pressure May Be Determined By a Rapid PEEP-Step Procedure

2021 ◽  
Author(s):  
Christina Grivans ◽  
Ola Stenqvist
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Peep Level ◽  
Ideal Body Weight ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Lung Compliance ◽  
Driving Pressure ◽  
Step Procedure ◽  
Ideal Body

Abstract Background: A protective ventilation strategy should be based on lung mechanics and transpulmonary pressure, as this is the pressure that directly “hits” the lung. Esophageal pressure has been used for this purpose but has not gained widespread clinical acceptance. Instead, respiratory system mechanics and airway driving pressure have been used as surrogate measures. We have shown that the lung pressure/volume (P/V) curve coincides with the line connecting the end-expiratory airway P/V points of a PEEP trial. Consequently, transpulmonary pressure increases as much as PEEP and lung compliance (CL) can be determined as ΔEELV/ΔPEEP and transpulmonary driving pressure (ΔPTP) as tidal volume divided by ΔEELV/ΔPEEP.Methods: In ten patients with acute respiratory failure, ΔEELV was measured during each 4 cmH2O PEEP-step from 0 to 16 cmH2O and CL for each PEEP interval calculated as ΔEELV/ΔPEEP giving a lung P/V curve for the whole PEEP trial. Similarily, a lung P/V curve was obtained also for the PEEP levels 8, 12, and 16 cmH2O only.Results: A two-step PEEP procedure starting from a clinical PEEP level of 8 cmH2O gave almost identical lung P/V curves as the four PEEP-step procedure. The lung P/V curves showed a marked individual variation with an over-all CL (CLoa ) 50-137 ml/cmH2O. ΔPTP of a tidal volume of 6-7 ml/kg ideal body weight divided by CLoa ranged from 8.6-2.8 cmH2O, while ΔPTP of tidal volume adapted to CLoa ranged from 3.3 in the patient with lowest to 4.3 cmH 2 O in the patient with highest CLoa . The ratio of airway driving pressure to transpulmonary driving pressure (ΔPTP/ΔPAW) varied between patients and changed with PEEP, reducing the value of ΔPAW as surrogate for ΔPTP in individual patients.Conclusion: Only a two PEEP-step procedure is required for obtaining a lung P/V curve from baseline clinical PEEP to end-inspiration at the highest PEEP level, i.e. without esophageal pressure measurements. The best-fit equation for the curve can be used to determine a tidal volume related to lung compliance instead of ideal body weight and the PEEP level where transpulmonary driving pressure is lowest and possibly least injurious for any given tidal volume.

scholarly journals Protective PEEP and Lung Capacity May Be Determined by a Rapid PEEP-step Procedure

2021 ◽  
Author(s):  
Christina Grivans ◽  
Ola Stenqvist
Keyword(s):  
Tidal Volume ◽  
Peep Level ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Plateau Pressure ◽  
Lung Compliance ◽  
Driving Pressure ◽  
High Peep ◽  
Step Procedure ◽  
Protective Ventilation Strategy

Abstract Background: A protective ventilation strategy should be based on assessment of lung mechanics and transpulmonary pressure, as this is the pressure that directly “hits” the lung. Esophageal pressure has been used for this purpose but has not gained widespread clinical acceptance. Instead, respiratory system mechanics and airway driving pressure have been used as surrogate measures. We have shown that the lung P/V curve coincides with the line connecting the end-expiratory airway P/V points of a PEEP trial. Consequently, transpulmonary pressure increases as much as PEEP is increased. If the change in end-expiratory lung volume (ΔEELV) is determined, lung compliance (CL) can be determined as ΔEELV/ΔPEEP and ΔPTP as tidal volume times ΔPEEP/ΔEELV. Methods: In ten patients with acute respiratory failure, ΔEELV was measured during each 4 cmH2O PEEP-step from 0 to 16 cmH2O and CL for each PEEP interval calculated as ΔEELV/ΔPEEP giving a lung P/V curve for the whole PEEP trial. Results: Lung P/V curves showed a marked individual variation with an overall lung compliance of 43–143 ml/cmH2O (total inspiratory volume divided by end-inspiratory transpulmonary plateau pressure at PEEP 16 cmH2O). The two patients with lowest lung compliance were non-responders to PEEP with decreasing lung compliance at high PEEP levels, indicating over-distension. Patients with higher lung compliance had a positive response to PEEP with successively higher lung compliance when increasing PEEP. A two-step PEEP procedure starting from a clinical PEEP level of 8 cmH2O gave almost identical lung P/V curves as the four PEEP-step procedure. The ratio of airway driving pressure (ΔPAW) to transpulmonary driving pressure (ΔPTP/ΔPAW) varied between patients and changed with PEEP, reducing the value of ΔPAW as surrogate for ΔPTP in individual patients. Conclusion: Separation of lung and chest wall mechanics can be achieved without esophageal pressure measurements if ΔEELV is determined when PEEP is changed . Only a two-step PEEP procedure is required for obtaining a lung P/V curve from baseline clinical PEEP to end-inspiration at the highest PEEP level, which can be used to determine the PEEP level where transpulmonary driving pressure is lowest and possibly least injurious for any given tidal volume.Trial registration: ClinicalTrials.gov, NCT04484727. Registered 24 July 2020 – Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04484727?term=Lindgren%2C+Sophie&cntry=SE&draw=2&rank=1

scholarly journals Managing Hypercapnia in Patients with Severe ARDS and Low Respiratory System Compliance: The Role of Esophageal Pressure Monitoring—A Case Cohort Study

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Arie Soroksky ◽  
Julia Kheifets ◽  
Zehava Girsh Solomonovich ◽  
Emad Tayem ◽  
Balmor Gingy Ronen ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Tidal Volume ◽  
Distress Syndrome ◽  
Ideal Body Weight ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Successful Management ◽  
Esophageal Balloon ◽  
Ideal Body

Purpose. Patients with severe acute respiratory distress syndrome (ARDS) and hypercapnia present a formidable treatment challenge. We examined the use of esophageal balloon for assessment of transpulmonary pressures to guide mechanical ventilation for successful management of severe hypercapnia.Materials and Methods. Patients with severe ARDS and hypercapnia were studied. Esophageal balloon was inserted and mechanical ventilation was guided by assessment of transpulmonary pressures. Positive end expiratory pressure (PEEP) and inspiratory driving pressures were adjusted with the aim of achieving tidal volume of 6 to 8 mL/kg based on ideal body weight (IBW), while not exceeding end inspiratory transpulmonary (EITP) pressure of 25 cm H2O.Results. Six patients with severe ARDS and hypercapnia were studied. Mean PaCO2on enrollment was108.33±25.65 mmHg. One hour after adjustment of PEEP and inspiratory driving pressure guided by transpulmonary pressure, PaCO2decreased to64.5±16.89 mmHg (P<0.01). Tidal volume was3.96±0.92 mL/kg IBW before and increased to7.07±1.21 mL/kg IBW after intervention(P<0.01). EITP pressure before intervention was low with a mean of13.68±8.69 cm H2O and remained low at16.76±4.76 cm H2O (P=0.18) after intervention. Adjustment of PEEP and inspiratory driving pressures did not worsen oxygenation and did not affect cardiac output significantly.Conclusion. The use of esophageal balloon as a guide to mechanical ventilation was able to treat severe hypercapnia in ARDS patients.

scholarly journals Differential Ventilation Using Flow Control Valves as a Potential Bridge to Full Ventilatory Support during the COVID-19 Crisis

2020 ◽  
Vol 133 (4) ◽  
pp. 892-904 ◽  
Author(s):  
Matthew A. Levin ◽  
Anjan Shah ◽  
Ronak Shah ◽  
Erica Kane ◽  
George Zhou ◽  
...  
Keyword(s):  
Body Weight ◽  
Flow Control ◽  
Tidal Volume ◽  
Coefficient Of Variation ◽  
Ideal Body Weight ◽  
Lung Compliance ◽  
Control Mode ◽  
Control Valves ◽  
Differential Ventilation ◽  
Ideal Body

Background During the COVID-19 pandemic, ventilator sharing was suggested to increase availability of mechanical ventilation. The safety and feasibility of ventilator sharing is unknown. Methods A single ventilator in pressure control mode was used with flow control valves to simultaneously ventilate two patients with different lung compliances. The system was first evaluated using high-fidelity human patient simulator mannequins and then tested for 1 h in two pairs of COVID-19 patients with acute respiratory failure. Patients were matched on positive end-expiratory pressure, fractional inspired oxygen tension, and respiratory rate. Tidal volume and peak airway pressure (PMAX) were recorded from each patient using separate independent spirometers and arterial blood gas samples drawn at 0, 30, and 60 min. The authors assessed acid-base status, oxygenation, tidal volume, and PMAX for each patient. Stability was assessed by calculating the coefficient of variation. Results The valves performed as expected in simulation, providing a stable tidal volume of 400 ml each to two mannequins with compliance ratios varying from 20:20 to 20:90 ml/cm H2O. The system was then tested in two pairs of patients. Pair 1 was a 49-yr-old woman, ideal body weight 46 kg, and a 55-yr-old man, ideal body weight 64 kg, with lung compliance 27 ml/cm H2O versus 35 ml/cm H2O. The coefficient of variation for tidal volume was 0.2 to 1.7%, and for PMAX 0 to 1.1%. Pair 2 was a 32-yr-old man, ideal body weight 62 kg, and a 56-yr-old woman, ideal body weight 46 kg, with lung compliance 12 ml/cm H2O versus 21 ml/cm H2O. The coefficient of variation for tidal volume was 0.4 to 5.6%, and for PMAX 0 to 2.1%. Conclusions Differential ventilation using a single ventilator is feasible. Flow control valves enable delivery of stable tidal volume and PMAX similar to those provided by individual ventilators. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

scholarly journals Pulmonary Effects of Adjusting Tidal Volume to Actual or Ideal Body Weight in Ventilated Obese Mice

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Elise Guivarch ◽  
Guillaume Voiriot ◽  
Anahita Rouzé ◽  
Stéphane Kerbrat ◽  
Jeanne Tran Van Nhieu ◽  
...  
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Ideal Body Weight ◽  
Obese Mice ◽  
Ideal Body

scholarly journals IS SELECTION OF TIDAL VOLUME BASED ON PATIENTS IDEAL BODY WEIGHT?

CHEST Journal ◽  
2020 ◽  
Vol 157 (6) ◽  
pp. A415
Author(s):  
A. Alotaibi ◽  
A. Almajhad ◽  
F. Othman ◽  
T. Ismaeil ◽  
Y. Ismaiel ◽  
...  
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Ideal Body Weight ◽  
Ideal Body ◽  
Selection Of

scholarly journals Intraoperative physiological ranges associated with improved outcomes after major spine surgery: an observational study

BMJ Open ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. e025337
Author(s):  
Gang Li ◽  
Liang Lin ◽  
Jifang Xiao ◽  
Stanley Rosenbaum ◽  
Philip Bickler ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Observational Study ◽  
Tidal Volume ◽  
Spine Surgery ◽  
Ideal Body Weight ◽  
Convenience Sample ◽  
Physiological Variables ◽  
Improved Outcomes ◽  
Ideal Body

ObjectiveThere is inadequate information about the values of many intraoperative physiological measurements that are associated with improved outcomes after surgery. The purpose of this observational study is to investigate the optimal physiological ranges during major spine surgery.SettingA teaching hospital in the USA.ParticipantsA convenience sample of 102 patients receiving major posterior spine surgery with multilevel spinal fusion in a prone position.MethodsPhysiological variables, including but not limited to mean arterial pressure (MAP) and cerebral and somatic tissue oxygen saturation (SctO2/SstO2), were recorded. The results of these measurements were associated with length of hospital stay and composite complication data and were analysed based on thresholds (ie, a cut-off value for optimal and suboptimal physiology) and the area under the curve (AUC) values. The AUC values were measured as the area enclosed by the actual tracing and the threshold. The outcomes were dichotomised into above-average and below-average (ie, improved) categories.ResultsAnalyses based on thresholds identified the following variables associated with above-average outcomes: MAP <60 mm Hg, temperature <35°C, heart rate >90 beats per minute (bpm), SctO2 <60% and SstO2 >80%. Analyses based on AUC values identified the following as associated with above-average outcomes: MAP <70 and >100 mm Hg, temperature <36°C, heart rate >90 bpm, tidal volume (based on ideal body weight)<6 mL/kg, tidal volume (based on actual body weight) >10 mL/kg and peak airway pressure <15 cmH2O.ConclusionThe following physiological ranges are associated with improved outcomes (ie, shorter hospitalisation and fewer complications) during major spine surgery: MAP of 70–100 mm Hg, temperature ≥36°C, heart rate <90 bpm, tidal volume based on ideal body weight >6 mL/kg, SctO2 >60% and SstO2 <80%.

Effects Of Adjusting Tidal Volume On Actual Or Ideal Body Weight In Ventilated Obese Mice

2012 ◽  
Author(s):  
Elise Guivarch ◽  
Guillaume Voiriot ◽  
Anahita Rouze ◽  
Jeanne Tran Van NHieu ◽  
Philippe Montravers ◽  
...  
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Ideal Body Weight ◽  
Obese Mice ◽  
Ideal Body

Determining Ideal Body Weight (and Mass)

1983 ◽  
Vol 40 (10) ◽  
pp. 1622-1627 ◽  
Author(s):  
Alan W. Hopefl ◽  
Donald R. Miller ◽  
James D. Carlson ◽  
Beverly J. Lloyd ◽  
Brian Jack Day ◽  
...  
Keyword(s):  
Body Weight ◽  
Ideal Body Weight ◽  
Ideal Body

scholarly journals Dosing of neuromuscular blocking agents in patients with obesity: A narrative review

2021 ◽  
pp. 0310057X2096857
Author(s):  
Brian L Erstad ◽  
Jeffrey F Barletta
Keyword(s):  
Body Weight ◽  
Ideal Body Weight ◽  
Neuromuscular Blocking ◽  
Neuromuscular Blocking Agents ◽  
Patient Specific ◽  
Lean Body Weight ◽  
Short Term ◽  
Blocking Agents ◽  
Ideal Body ◽  
Size Descriptor

There is no consensus on which weight clinicians should use for weight-based dosing of neuromuscular blocking agents (NMBAs), as exemplified by differing or absent recommendations in clinical practice guidelines. The purpose of this paper is to review studies that evaluated various size descriptors for weight-based dosing of succinylcholine and non-depolarising NMBAs, and to provide recommendations for the descriptors of choice for the weight-based dosing of these agents in patients with obesity. All of the studies conducted to date involving depolarising and non-depolarising NMBAs in patients with obesity have assessed single doses or short-term infusions conducted in perioperative settings. Recognising that any final dosing regimen must take into account patient-specific considerations, the available evidence suggests that actual body weight is the size descriptor of choice for weight-based dosing of succinylcholine and that ideal body weight, or an adjusted (or lean) body weight, is the size descriptor of choice for weight-based dosing of non-depolarising NMBAs.

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