scholarly journals Evaluation of alveolar recruitment maneuver on respiratory resistance during general anesthesia: a prospective observational study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Junko Nakahira ◽  
Shoko Nakano ◽  
Toshiaki Minami
Keyword(s):  
Mechanical Ventilation ◽  
General Anesthesia ◽  
Recruitment Maneuver ◽  
Peak Inspiratory Pressure ◽  
Alveolar Recruitment ◽  
Trial Registration ◽  
Inspiratory Pressure ◽  
Forced Oscillation Technique ◽  
Respiratory Resistance ◽  
Recruitment Maneuvers

Abstract Background Alveolar recruitment maneuvers enable easily reopening nonaerated lung regions via a transient elevation in transpulmonary pressure. To evaluate the effect of these maneuvers on respiratory resistance, we used an oscillatory technique during mechanical ventilation. This study was conducted to assess the effect of the alveolar recruitment maneuvers on respiratory resistance under routine anesthesia. We hypothesized that respiratory resistance at 5 Hz (R5) after the maneuver would be decreased after the lung aeration. Methods After receiving the ethics committee’s approval, we enrolled 33 patients who were classified with an American Society of Anesthesiologists physical status of 1, 2 or 3 and were undergoing general anesthesia for transurethral resection of a bladder tumor within a 12-month period from 2017 to 2018. The recruitment maneuver was performed 30 min after endotracheal intubation. The maneuver consisted of sustained manual inflation of the anesthesia reservoir bag to a peak inspiratory pressure of 40 cmH2O for 15 s, including 5 s of gradually increasing the peak inspiratory pressure. Respiratory resistance was measured using the forced oscillation technique before and after the maneuver, and the mean R5 was calculated during the expiratory phase. The respiratory resistance and ventilator parameter results were analyzed using paired Student’s t-tests, and p < 0.05 was considered statistically significant. Results We analyzed 31 patients (25 men and 6 women). R5 was 7.3 ± 1.6 cmH2O/L/sec before the recruitment maneuver during mechanical ventilation and was significantly decreased to 6.4 ± 1.7 cmH2O/L/sec after the maneuver. Peak inspiratory pressure and plateau pressure were significantly decreased, and pulmonary compliance was increased, although the values were not clinically relevant. Conclusion The recruitment maneuver decreased respiratory resistance and increased lung compliance during mechanical ventilation. Trial registration Name of registry: Japan Medical Association Center for Clinical Trials. Trial registration number: reference JMA-IIA00136. Date of registration: 2 September 2013. URL of trial registry record: https://dbcentre3.jmacct.med.or.jp/JMACTR/App/JMACTRE02_04/JMACTRE02_04.aspx?kbn=3&seqno=3582

scholarly journals Quantitative imaging of alveolar recruitment with hyperpolarized gas MRI during mechanical ventilation

2011 ◽  
Vol 110 (2) ◽  
pp. 499-511 ◽  
Author(s):  
Maurizio Cereda ◽  
Kiarash Emami ◽  
Stephen Kadlecek ◽  
Yi Xin ◽  
Puttisarn Mongkolwisetwara ◽  
...  
Keyword(s):  
Quantitative Imaging ◽  
Peak Inspiratory Pressure ◽  
Relative Difference ◽  
Relative Increase ◽  
Alveolar Recruitment ◽  
Inspiratory Pressure ◽  
Sprague Dawley ◽  
Recruitment Maneuvers ◽  
Before And After ◽  
Hyperpolarized Gas Mri

The aim of this study was to assess the utility of 3He MRI to noninvasively probe the effects of positive end-expiratory pressure (PEEP) maneuvers on alveolar recruitment and atelectasis buildup in mechanically ventilated animals. Sprague-Dawley rats ( n = 13) were anesthetized, intubated, and ventilated in the supine position (4He-to-O2 ratio: 4:1; tidal volume: 10 ml/kg, 60 breaths/min, and inspiration-to-expiration ratio: 1:2). Recruitment maneuvers consisted of either a stepwise increase of PEEP to 9 cmH2O and back to zero end-expiratory pressure or alternating between these two PEEP levels. Diffusion MRI was performed to image 3He apparent diffusion coefficient (ADC) maps in the middle coronal slices of lungs ( n = 10). ADC was measured immediately before and after two recruitment maneuvers, which were separated from each other with a wait period (8–44 min). We detected a statistically significant decrease in mean ADC after each recruitment maneuver. The relative ADC change was −21.2 ± 4.1 % after the first maneuver and −9.7 ± 5.8 % after the second maneuver. A significant relative increase in mean ADC was observed over the wait period between the two recruitment maneuvers. The extent of this ADC buildup was time dependent, as it was significantly related to the duration of the wait period. The two postrecruitment ADC measurements were similar, suggesting that the lungs returned to the same state after the recruitment maneuvers were applied. No significant intrasubject differences in ADC were observed between the corresponding PEEP levels in two rats that underwent three repeat maneuvers. Airway pressure tracings were recorded in separate rats undergoing one PEEP maneuver ( n = 3) and showed a significant relative difference in peak inspiratory pressure between pre- and poststates. These observations support the hypothesis of redistribution of alveolar gas due to recruitment of collapsed alveoli in presence of atelectasis, which was also supported by the decrease in peak inspiratory pressure after recruitment maneuvers.

scholarly journals Efficacy of Alveolar Recruitment Maneuvers in the Adult Obese Patient Undergoing General Anesthesia: A Systematic Review of the Literature

2018 ◽  
Author(s):  
Joseph Banks
Keyword(s):  
Systematic Review ◽  
Mechanical Ventilation ◽  
General Anesthesia ◽  
Obese Patient ◽  
Perioperative Period ◽  
Lung Compliance ◽  
Alveolar Recruitment ◽  
Respiratory Physiology ◽  
Arterial Oxygen ◽  
Recruitment Maneuvers

There are many pathophysiologic health effects associated with obesity, and the effects on normal respiratory physiology can be profound. The presence of increased adipose tissue can limit a patient’s functional residual capacity, reduce end expiratory lung volumes, and increase small airway closure. When exposed to general anesthesia with mechanical ventilation these physiologic changes can increase atelectasis development and increase the likelihood of ventilation-perfusion mismatching. Alveolar recruitment maneuvers are brief applications of positive airway pressure that are employed to recruit alveoli that have already collapsed and prevent new atelectasis formation. The purpose of this systematic review was to determine if the use of alveolar recruitment maneuvers are a safe and effective treatment strategy for managing the adult obese patient requiring general anesthesia with mechanical ventilation. The theoretical framework that guided this systematic review was the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Randomized control trials that utilized alveolar recruitment maneuvers in adult obese patients were reviewed and appraised for inclusion in this systematic review. It was determined that alveolar recruitment maneuvers are a safe and effective strategy for minimizing atelectasis development in the adult obese patient undergoing general anesthesia. Alveolar recruitment maneuvers were associated with an improved intraoperative oxygenation, a decreased alveolar-arterial oxygen concentration gradient, and improved lung compliance. Furthermore, alveolar recruitment maneuver use demonstrated a decrease in atelectasis development measured via computed tomography and radiograph imaging. Application of these maneuvers in the obese patient during the perioperative period can improve ventilation-perfusion matching and decrease respiratory complications associated with atelectasis development.

scholarly journals The Effect of Ultrasound-Guided Lung Recruitment Maneuvers On Atelectasis In Lung-Healthy Patients Undergoing Laparoscopic Gynecologic Surgery: a Randomized Controlled Trial

2021 ◽  
Author(s):  
Yi Liu ◽  
Jingyu Wang ◽  
Yong Wan ◽  
Yuan Geng ◽  
Yiran Zhang ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
General Anesthesia ◽  
Lung Ultrasound ◽  
Pulmonary Complications ◽  
Lung Recruitment ◽  
Gynecologic Surgery ◽  
Postoperative Pulmonary Complications ◽  
Ultrasound Guided ◽  
Recruitment Maneuvers ◽  
Laparoscopic Gynecologic Surgery

Abstract BackgroundAtelectasis is a major cause of hypoxemia during general anesthesia and postoperative pulmonary complications (PPCs).Some previous reported that the combined use of lung recruitment procedures (LRMs) and positive end-expiratory pressure (PEEP) in mechanical ventilation mode contributes to the avoidance of PPCs in patients after general anesthesia, while others suggest that the use of LRMs makes patients more susceptible to hemodynamic disturbances and lung injury, and is of limited potential to decrease the incidence of PPCs. From this perspective, controversy exists as to whether LRMs should be routinely applied to surgical patients. More importantly, corresponding clinical studies are also lacking. Therefore, this trial was conducted with the aim of solving the above problem.MethodsIn current clinical trial, patients undergoing laparoscopic gynecologic surgery with healthy lungs were randomized to the recruitment maneuvers group (RM group; 6 cm H2O PEEP and RMs) and the control group (C group; 6 cm H2O PEEP and no RMs). Lung ultrasound was performed on patients at five separate time points. During mechanical ventilation, patients in the RM group received ultrasound-guided pulmonary resuscitation when atelectasis was detected, while the C group did not intervene. Lung ultrasound scores were used to evaluate the incidence and severity of atelectasis.ResultsAfter LRMs, the incidence of atelectasis was significantly lower in the RM group (40%) than in the C group (80%) 15 minutes after arrival in the post-anesthesia care unit (PACU), and this difference did not persist for 24 hours after surgery. Meanwhile, postoperative pulmonary complications showed no difference between the two groups.ConclusionsThe combination of LRMs and PEEP decreased the incidence of atelectasis 15 minutes after admission to the PACU, but did not improve PPCs in adults with healthy lungs. Hence, for lung-healthy patients undergoing gynecological laparoscopic surgery, we do not recommend routine recruitment maneuvers. Trial registration: (prospectively registered): ChiCTR2000033529. Registered on 6/4/2020.

Practical Review of Mechanical Ventilation in Adults and Children in The Operating Room and Emergency Department

2021 ◽  
Vol 16 ◽  
Author(s):  
Christian Zanza ◽  
Yaroslava Longhitano ◽  
Mirco Leo ◽  
Tatsiana Romenskaya ◽  
Francesco Franceschi ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Operating Room ◽  
Protective Ventilation ◽  
Alveolar Recruitment ◽  
Cochrane Library ◽  
Surgical Patient ◽  
Emergency Setting ◽  
Recruitment Maneuvers ◽  
Operative Complications ◽  
Post Operative Complications

Background: During general anesthesia, mechanical ventilation can cause pulmonary damage through mechanism of ventilator-induced lung injury which is a major cause of postoperative pulmonary complications, which varies between 5 and 33% and increases significantly the 30-day mortality of the surgical patient. Objective: The aim of this review is to analyze different variables which played key role in safe application of mechanical ventilation in the operating room and emergency setting. Method: Also, we wanted to analyze different types of population that underwent intraoperative mechanical ventilation like obese patients, pediatric and adult population and different strategies such as one lung ventilation and ventilation in trendelemburg position. The peer-reviewed articles analyzed were selected according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) from Pubmed/Medline, Ovid/Wiley and Cochrane Library, combining key terms such as: “pulmonary post-operative complications”, “protective ventilation”, “alveolar recruitment maneuvers”, “respiratory compliance”, “intraoperative paediatric ventilation”, “best peep”, “types of ventilation”. Among the 230 papers identified, 150 articles were selected, after title - abstract examination and removing the duplicates, resulting in 94 articles related to mechanical ventilation in operating room and emergency setting that were analyzed. Results: Careful preoperative patient’s evaluation and protective ventilation (i.e. use of low tidal volumes, adequate PEEP and alveolar recruitment maneuvers) has been shown to be effective not only in limiting alveolar de-recruitment, alveolar overdistension and lung damage, but also in reducing the onset of pulmonary post-operative complications (PPCs). Conclusion: Mechanical ventilation is like “Janus Bi-front” because it is essential for surgical procedures, for the care of critical care patients and in life-threatening conditions but it can be harmful to the patient if continued for a long time and where an excessive dose of oxygen is administered into the lungs. Low tidal volume is associated with minor rate of PPCs and other complications and every complication can increase length of Stay, adding cost to NHS between 1580 € and 1650 € per day in Europe and currently the prevention of PPCS is only weapon that we possess.

Acute lung injury from mechanical ventilation at moderately high airway pressures

1990 ◽  
Vol 69 (3) ◽  
pp. 956-961 ◽  
Author(s):  
K. Tsuno ◽  
P. Prato ◽  
T. Kolobow
Keyword(s):  
Mechanical Ventilation ◽  
Peak Inspiratory Pressure ◽  
Blood Gases ◽  
Inspiratory Pressure ◽  
Control Group ◽  
Arterial Blood Gases ◽  
Lung Weight ◽  
Pulmonary Atelectasis ◽  
Arterial Pco2 ◽  
Arterial Blood

We have explored adverse pulmonary effects of mechanical ventilation at a peak inspiratory pressure of 30 cmH2O in paralyzed and anesthetized healthy sheep. A control group of eight sheep (group A) was mechanically ventilated with 40% oxygen at a tidal volume of 10 ml/kg, a frequency of 15 breaths/min, a peak inspiratory pressure less than 18 cmH2O, and a positive end-expiratory pressure of 3-5 cmH2O. During the ensuing 48 h, there were no measurable deleterious changes in lung function or arterial blood gases. Another 19 sheep were ventilated with 40% oxygen at a peak inspiratory pressure of 30 cmH2O under a different set of conditions and were randomly assigned to two groups. In group B, the respiratory rate was kept near 4 breaths/min to keep arterial PCO2 in the normal range; in group C, the frequency was kept near 15 breaths/min by including a variable dead space in the ventilator circuit to keep arterial PCO2 near baseline values. There was a progressive deterioration in total static lung compliance, functional residual capacity, and arterial blood gases. After some hours, there were abnormal chest roentgenographic changes. At time of death we found severe pulmonary atelectasis, increased wet lung weight, and an increase in the minimum surface tension of saline lung lavage fluid.

Sustained isocapnic hypoxia suppresses the perception of the magnitude of inspiratory resistive loads

2000 ◽  
Vol 89 (1) ◽  
pp. 47-55 ◽  
Author(s):  
R. S. Orr ◽  
A. S. Jordan ◽  
P. Catcheside ◽  
N. A. Saunders ◽  
R. D. McEvoy
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Peak Inspiratory Pressure ◽  
Normal Subjects ◽  
Inspiratory Pressure ◽  
Respiratory Resistance ◽  
Stimulus Magnitude ◽  
Mean Values ◽  
Central Nervous System Depressant ◽  
Resistive Loads

The sensation of increased respiratory resistance or effort is likely to be important for the initiation of alerting or arousal responses, particularly in sleep. Hypoxia, through its central nervous system-depressant effects, may decrease the perceived magnitude of respiratory loads. To examine this, we measured the effect of isocapnic hypoxia on the ability of 10 normal, awake males (mean age = 24.0 ± 1.8 yr) to magnitude-scale five externally applied inspiratory resistive loads (mean values from 7.5 to 54.4 cmH2O · l−1 · s). Each subject scaled the loads during 37 min of isocapnic hypoxia (inspired O2 fraction = 0.09, arterial O2 saturation of ∼80%) and during 37 min of normoxia, using the method of open magnitude numerical scaling. Results were normalized by modulus equalization to allow between-subject comparisons. With the use of peak inspiratory pressure (PIP) as the measure of load stimulus magnitude, the perception of load magnitude (Ψ) increased linearly with load and, averaged for all loaded breaths, was significantly lower during hypoxia than during normoxia (20.1 ± 0.9 and 23.9 ± 1.3 arbitrary units, respectively; P = 0.048). Ψ declined with time during hypoxia ( P = 0.007) but not during normoxia ( P= 0.361). Our result is remarkable because PIP was higher at all times during hypoxia than during normoxia, and previous studies have shown that an elevation in PIP results in increased Ψ. We conclude that sustained isocapnic hypoxia causes a progressive suppression of the perception of the magnitude of inspiratory resistive loads in normal subjects and could, therefore, impair alerting or arousal responses to respiratory loading.

scholarly journals Effect of Ultrasound-guided Lung Recruitment Maneuvers on Atelectasis in Lung-healthy Patients Undergoing Laparoscopic Gynecologic Surgery: a Randomized Controlled Trial

2021 ◽  
Author(s):  
Yi Liu ◽  
Jingyu Wang ◽  
Yong Wan ◽  
Yuan Geng ◽  
Yiran Zhang ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
General Anesthesia ◽  
Lung Ultrasound ◽  
Pulmonary Complications ◽  
Lung Recruitment ◽  
Gynecologic Surgery ◽  
Postoperative Pulmonary Complications ◽  
Ultrasound Guided ◽  
Recruitment Maneuvers ◽  
Laparoscopic Gynecologic Surgery

Abstract BackgroundAtelectasis is a major cause of hypoxemia during general anesthesia and postoperative pulmonary complications (PPCs).Some previous reported that the combined use of lung recruitment procedures (LRMs) and positive end-expiratory pressure (PEEP) in mechanical ventilation mode contributes to the avoidance of PPCs in patients after general anesthesia, while others suggest that the use of LRMs makes patients more susceptible to hemodynamic disturbances and lung injury, and is of limited potential to decrease the incidence of PPCs. From this perspective, controversy exists as to whether LRMs should be routinely applied to surgical patients. More importantly, corresponding clinical studies are also lacking. Therefore, this trial was conducted with the aim of solving the above problem.MethodsIn current clinical trial, patients undergoing laparoscopic gynecologic surgery with healthy lungs were randomized to the recruitment maneuvers group (RM group; 6 cm H2O PEEP and RMs) and the control group (C group; 6 cm H2O PEEP and no RMs). Lung ultrasound was performed on patients at five separate time points. During mechanical ventilation, patients in the RM group received ultrasound-guided pulmonary resuscitation when atelectasis was detected, while the C group did not intervene. Lung ultrasound scores were used to evaluate the incidence and severity of atelectasis.ResultsAfter LRMs, the incidence of atelectasis was significantly lower in the RM group (40%) than in the C group (80%) 15 minutes after arrival in the post-anesthesia care unit (PACU), and this difference did not persist for 24 hours after surgery. Meanwhile, postoperative pulmonary complications showed no difference between the two groups.ConclusionsThe combination of LRMs and PEEP decreased the incidence of atelectasis 15 minutes after admission to the PACU, but did not improve PPCs in adults with healthy lungs. Hence, for lung-healthy patients undergoing gynecological laparoscopic surgery, we do not recommend routine recruitment maneuvers. Trial registration (prospectively registered)ChiCTR2000033529. Registered on June 4, 2020.

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