scholarly journals Efficacy of Different Recruitment Maneuvers for Improved Lung Inhomogeneity in a Pig Model of ARDS

2020 ◽  
Author(s):  
Feiping Xia ◽  
Chun Pan ◽  
Lihui Wang ◽  
Ling Liu ◽  
Songqiao Liu ◽  
...  
Keyword(s):  
Random Order ◽  
Lung Compliance ◽  
Pig Model ◽  
Impedance Tomography ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Recruitment Maneuvers ◽  
Sustained Inflation ◽  
Significant Difference ◽  
Before And After

Abstract Background: In acute respiratory distress syndrome (ARDS), lung recruitment maneuvers can recruit collapsed alveoli in gravity-dependent lung regions, improving the homogeneity of ventilation distribution. This study used electrical impedance tomography (EIT) to investigate the efficacy of different recruitment maneuvers for alveolar recruitment in a pig model of ARDS. Methods: ARDS was induced in ten healthy male pigs with repeated bronchoalveolar lavage until the arterial partial pressure of oxygen (PaO 2 )/fraction of inspired oxygen (FiO 2 ) (P/F ratio) was < 100 mmHg and remained stable for 30 minutes (TARDS). ARDS pigs underwent three sequential recruitment maneuvers, including sustained inflation (SI), increments of positive end-expiratory pressure (PEEP) (IP), and pressure-controlled ventilation (PCV) applied in random order, with 30 mins at a PEEP of 5 cmH 2 O between maneuvers. Respiratory mechanics, hemodynamics, arterial blood gas, and EIT were recorded at baseline, TARDS, and before and after each recruitment maneuver.Results: In all ten pigs, ARDS was successfully induced with a mean 2.8±1.03 (2800±1032.80ml) bronchoalveolar lavages. PaO 2 , SO 2 , P/F, and compliance were significantly improved after recruitment with SI, IP or PCV (all p<0.05), and there were no significant differences between maneuvers. Global inhomogeneity (GI) was significantly decreased after recruitment with SI, IP, or PCV. There were no significant differences in GI before or after recruitment with the different maneuvers. The decrease in GI (ΔGI) was significantly greater after recruitment with IP compared to SI (p=0.023), but there was no significant difference in ΔGI between IP and PCV. Conclusion: SI, IP, and PCV increased oxygenation, regional compliance and lung compliance, and decreased inhomogeneous gas distribution with no adverse effects on hemodynamics in ARDS pigs. IP significantly improved inhomogeneity of the lung compared to SI.

scholarly journals Physiological Effects of Different Recruitment Maneuvers in a Pig Model of ARDS

2020 ◽  
Author(s):  
Feiping Xia ◽  
Chun Pan ◽  
Lihui Wang ◽  
Ling Liu ◽  
Songqiao Liu ◽  
...  
Keyword(s):  
Random Order ◽  
Pig Model ◽  
Physiological Effects ◽  
Impedance Tomography ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Recruitment Maneuvers ◽  
Sustained Inflation ◽  
Significant Difference ◽  
Before And After

Abstract Background: In acute respiratory distress syndrome (ARDS), lung recruitment maneuvers can recruit collapsed alveoli in gravity-dependent lung regions, improving the homogeneity of ventilation distribution. This study used electrical impedance tomography (EIT) to investigate the physiological effects of different recruitment maneuvers for alveolar recruitment in a pig model of ARDS. Methods: ARDS was induced in ten healthy male pigs with repeated bronchoalveolar lavage until the arterial partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) (P/F ratio) was < 100 mmHg and remained stable for 30 minutes (TARDS). ARDS pigs underwent three sequential recruitment maneuvers, including sustained inflation (SI), increments of positive end-expiratory pressure (PEEP) (IP), and pressure-controlled ventilation (PCV) applied in random order, with 30 mins at a PEEP of 5 cmH2O between maneuvers. Respiratory mechanics, hemodynamics, arterial blood gas, and EIT were recorded at baseline, TARDS, and before and after each recruitment maneuver.Results: In all ten pigs, ARDS was successfully induced with a mean 2.8±1.03L (2800±1032.80ml) bronchoalveolar lavages. PaO2, SO2, P/F, and compliance were significantly improved after recruitment with SI, IP or PCV (all p<0.05), and there were no significant differences between maneuvers. Global inhomogeneity (GI) was significantly decreased after recruitment with SI, IP, or PCV. There were no significant differences in GI before or after recruitment with the different maneuvers. The decrease in GI (ΔGI) was significantly greater after recruitment with IP compared to SI (p=0.023), but there was no significant difference in ΔGI between IP and PCV.Conclusion: SI, IP, and PCV increased oxygenation, and regional and global compliance of the respiratory system, and decreased inhomogeneous gas distribution in ARDS pigs. IP significantly improved inhomogeneity of the lung compared to SI.

scholarly journals Physiological Effects of Different Recruitment Maneuvers for Improved Lung Inhomogeneity in a Pig Model of ARDS

2020 ◽  
Author(s):  
Feiping Xia ◽  
Chun Pan ◽  
Lihui Wang ◽  
Ling Liu ◽  
Songqiao Liu ◽  
...  
Keyword(s):  
Random Order ◽  
Pig Model ◽  
Physiological Effects ◽  
Impedance Tomography ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Recruitment Maneuvers ◽  
Sustained Inflation ◽  
Significant Difference ◽  
Before And After

Abstract Background: In acute respiratory distress syndrome (ARDS), lung recruitment maneuvers can recruit collapsed alveoli in gravity-dependent lung regions, improving the homogeneity of ventilation distribution. This study used electrical impedance tomography (EIT) to investigate the physiological effects of different recruitment maneuvers for alveolar recruitment in a pig model of ARDS. Methods: ARDS was induced in ten healthy male pigs with repeated bronchoalveolar lavage until the arterial partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) (P/F ratio) was < 100 mmHg and remained stable for 30 minutes (TARDS). ARDS pigs underwent three sequential recruitment maneuvers, including sustained inflation (SI), increments of positive end-expiratory pressure (PEEP) (IP), and pressure-controlled ventilation (PCV) applied in random order, with 30 mins at a PEEP of 5 cmH2O between maneuvers. Respiratory mechanics, hemodynamics, arterial blood gas, and EIT were recorded at baseline, TARDS, and before and after each recruitment maneuver.Results: In all ten pigs, ARDS was successfully induced with a mean 2.8±1.03L (2800±1032.80ml) bronchoalveolar lavages. PaO2, SO2, P/F, and compliance were significantly improved after recruitment with SI, IP or PCV (all p<0.05), and there were no significant differences between maneuvers. Global inhomogeneity (GI) was significantly decreased after recruitment with SI, IP, or PCV. There were no significant differences in GI before or after recruitment with the different maneuvers. The decrease in GI (ΔGI) was significantly greater after recruitment with IP compared to SI (p=0.023), but there was no significant difference in ΔGI between IP and PCV.Conclusion: SI, IP, and PCV increased oxygenation, and regional and global compliance of the respiratory system, and decreased inhomogeneous gas distribution in ARDS pigs. IP significantly improved inhomogeneity of the lung compared to SI.

scholarly journals Physiological effects of different recruitment maneuvers in a pig model of ARDS

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Feiping Xia ◽  
Chun Pan ◽  
Lihui Wang ◽  
Ling Liu ◽  
Songqiao Liu ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Pig Model ◽  
Physiological Effects ◽  
Impedance Tomography ◽  
Arterial Blood ◽  
Recruitment Maneuvers ◽  
Sustained Inflation ◽  
Significant Difference ◽  
Inhomogeneity Index

Abstract Background In acute respiratory distress syndrome (ARDS), lung recruitment maneuvers can recruit collapsed alveoli in gravity-dependent lung regions, improving the homogeneity of ventilation distribution. This study used electrical impedance tomography to investigate the physiological effects of different recruitment maneuvers for alveolar recruitment in a pig model of ARDS. Methods ARDS was induced in ten healthy male pigs with repeated bronchoalveolar lavage until the ratio of arterial partial pressure of oxygen (PaO2) of fraction of inspired oxygen (P/F) was < 100 mmHg and remained stable for 30 min (TARDS). ARDS pigs underwent three sequential recruitment maneuvers, including sustained inflation, increments of positive end-expiratory pressure (PEEP), and pressure-controlled ventilation (PCV) applied in random order, with 30 mins at a PEEP of 5 cmH2O between maneuvers. Respiratory mechanics, hemodynamics, arterial blood gas, and electrical impedance tomography were recorded at baseline, TARDS, and before and after each recruitment maneuver. Results In all ten pigs, ARDS was successfully induced with a mean 2.8 ± 1.03 L bronchoalveolar lavages. PaO2, P/F, and compliance were significantly improved after recruitment with sustained inflation, increments of PEEP or PCV (all p < 0.05), and there were no significant differences between maneuvers. Global inhomogeneity index significantly decreased after recruitment with sustained inflation, increments of PEEP, or PCV. There were no significant differences in global inhomogeneity before or after recruitment with the different maneuvers. The decrease in global inhomogeneity index (ΔGI) was significantly greater after recruitment with increments of PEEP compared to sustained inflation (p = 0.023), but there was no significant difference in ΔGI between increments of PEEP and PCV or between sustained inflation and PCV. Conclusion Sustained inflation, increments of PEEP, and PCV increased oxygenation, and regional and global compliance of the respiratory system, and decreased inhomogeneous gas distribution in ARDS pigs. Increments of PEEP significantly improved inhomogeneity of the lung compared to sustained inflation, while there was no difference between increments of PEEP and PCV or between sustained inflation and PCV.

Antigen-induced bronchospasm in conscious sheep

1979 ◽  
Vol 47 (5) ◽  
pp. 917-922 ◽  
Author(s):  
A. Wanner ◽  
R. J. Mezey ◽  
M. E. Reinhart ◽  
P. Eyre
Keyword(s):  
Lung Compliance ◽  
Base Line ◽  
Histamine Concentration ◽  
Mean Values ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Before And After ◽  
Residual Capacity ◽  
Plasma Histamine Concentration ◽  
Conscious Sheep

In 10 conscious ewes with cutaneous sensitivity to Ascaris suum, measurements of pulmonary resistance (RL), static lung compliance (Cst), functional residual capacity (FRC), and arterial blood gas composition along with arterial plasma histamine concentration (H) were obtained before and after inhalation challenge with A. suum extract. Five animals showed no changes in respiratory mechanics after A. suum challenge; in these H did not change. The remaining five animals responded to A. suum challenge with bronchospasm reflected by the following maximum changes in mean values that were significant 15 and 30 min after beginning of challenge, respectively: RL 248% , FRC 126%, specific pulmonary conductance 33%, and arterial PO2 63% of base line. These parameters returned towards base line by 120 min. No changes occurred in Cst, arterial PCO2, and pH. Five minutes after beginning of A. suum challenge, mean H was increased to 423% of base line with a return to base line 10 min later. In the same 5 animals, no changes were observed in pulmonary function or H after inhalation of ragweed extract (control). These results suggest that antigen-induced bronchospasm in sensitized conscious sheep represents an anaphylactic airway response and shares distinct physiological features with human bronchial asthma including pulmonary hyperinflation.

P18 Plasma-lyte 148 vs 0.9% saline for fluid resuscition in children: electrolytic and clinical outcomes

2018 ◽  
Vol 103 (2) ◽  
pp. e1.22-e1 ◽  
Author(s):  
Wignell Andrew ◽  
Davies Patrick
Keyword(s):  
Clinical Outcomes ◽  
Kidney Injury ◽  
Fluid Volume ◽  
Lower Percentage ◽  
Clinical Effects ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Significant Difference ◽  
Resuscitation Fluid ◽  
Plasma Chloride

AimsCrystalloid fluid boluses are a mainstay of treatment in unwell children, with the traditional fluid of choice being 0.9% saline (NS). However, the use of NS has been associated with an increase in plasma chloride levels and acidosis, leading to kidney injury and other detrimental clinical effects. Plasma-Lyte 148 (PLA) is a balanced, physiological, crystalloid intravenous fluid, which is both calcium-free and isotonic. Its use in place of NS for fluid resuscitation may circumvent hyperchloraemic metabolic acidosis. In May 2015 our hospital altered its standard resuscitation fluid from NS to PLA. We aimed to compare the effect of fluid boluses of NS to those of PLA in children.MethodsAll patients admitted in the 18 month periods before and after the change from NS to PLA, and receiving a fluid bolus in the first 24 hours of admission, were included. Post-surgical patients and those who had undergone haemofiltration were excluded. Arterial blood gas and creatinine values for up to 5 days after bolus fluid administration were examined. Patients were stratified according to the total resuscitation volume (ml/kg), then split into categories determined by the balance of PLA vs. NS.The primary outcome was plasma chloride. Secondary outcomes included blood pH and percentage change in creatinine. Clinical outcomes were length of ventilation and length of PICU stay.Results126 patients were included in the analysis. Patients receiving NS boluses tended to have a higher maximum chloride, higher average chloride, lower pH and higher percentage creatinine increase than those given PLA. Subgroup analysis showed a statistically significant difference in average serum chloride for the 61–90 ml/kg group {PLA 105.59±1.29 vs NS 111.29±2.1 mmol/L; difference: −6.21 [95% confidence interval (CI)−9.55,–2.87]}. Patients who received PLA tended to have a higher pH than those receiving NS. A statistically significant difference was seen in the 10–30 ml/kg group [PLA 7.42±0.49 vs NS 7.33±0.65; difference: 0.0913 (95% CI: −0.18 to −0.02)].Significant differences were not seen in the clinical outcomes of length of stay or ventilationConclusionPLA as a resuscitation fluid is significantly associated with a more physiological plasma chloride and pH across several resuscitation fluid volume categories, when compared to NS. The trends in the other fluid volume categories are in line with these findings, but are not statistically significant. There was also a trend towards patients receiving PLA having a lower percentage rise in creatinine than those who received saline. These results were consistent over all weight and age categories.

Feasıbılıty of Transcutaneous Method for Carbon Dıoxıde Monıtorıng in an Intensive Care Unıt

2022 ◽  
Vol 18 ◽  
Author(s):  
Nazlıhan Boyacı ◽  
Sariyya Mammadova ◽  
Nurgül Naurizbay ◽  
Merve Güleryüz ◽  
Kamil İnci ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
Partial Pressure ◽  
Blood Gas ◽  
Peripheral Oxygen Saturation ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Randomized Controlled Studies ◽  
Significant Difference

Background: Transcutaneous partial pressure of carbon dioxide (PtCO2) monitorization provides a continuous and non-invasive measurement of partial pressure of carbon dioxide (pCO2). In addition, peripheral oxygen saturation (SpO2) can also be measured and followed by this method. However, data regarding the correlation between PtCO2 and arterial pCO2 (PaCO2) measurements acquired from peripheric arterial blood gas is controversial. Objective: We aimed to determine the reliability of PtCO2 with PaCO2 based on its advantages, like non-invasiveness and continuous applicability. Methods: Thirty-five adult patients with hypercapnic respiratory failure admitted to our tertiary medical intensive care unit (ICU) were included. Then we compared PtCO2 and PaCO2 and both SpO2 measurements simultaneously. Thirty measurements from the deltoid zone and 26 measurements from the cheek zone were applied. Results: PtCO2 could not be measured from the deltoid region in 5 (14%) patients. SpO2 and pulse rate could not be detected at 8 (26.7%) of the deltoid zone measurements. Correlation coefficients between PtCO2 and PaCO2 from deltoid and the cheek region were r: 0,915 and r: 0,946 (p = 0,0001). In comparison with the Bland-Altman test, difference in deltoid measurements was -1,38 ± 1,18 mmHg (p = 0.252) and in cheek measurements it was -5,12 ± 0,92 mmHg (p = 0,0001). There was no statistically significant difference between SpO2 measurements in each region. Conclusion: Our results suggest that PtCO2 and SpO2 measurements from the deltoid region are reliable compared to the arterial blood gas analysis in hypercapnic ICU patients. More randomized controlled studies investigating the effects of different measurement areas, hemodynamic parameters, and hemoglobin levels are needed.

Furosemide in Hyaline Membrane Disease

PEDIATRICS ◽  
1978 ◽  
Vol 62 (5) ◽  
pp. 785-788
Author(s):  
Keith H. Marks ◽  
William Berman ◽  
Zvi Friedman ◽  
Victor Whitman ◽  
Cheryl Lee ◽  
...  
Keyword(s):  
Interstitial Fluid ◽  
Hyaline Membrane Disease ◽  
Skinfold Thickness ◽  
Acute Stage ◽  
Control Group ◽  
Arterial Blood Gas ◽  
Cardiorespiratory Function ◽  
Arterial Blood ◽  
Significant Difference ◽  
Hyaline Membrane

In a randomized clinical trial designed to evaluate the effect of diuresis on infants with hyaline membrane disease, seven infants were treated with furosemide (2 mg/kg intravenously) and five received 5% dextrose water in 0.225% sodium chloride (control group). Arterial blood gas analyses performed before and during the six hours after treatment showed no significant difference between control and treated infants. Urine output and urine sodium and calcium loss were significantly increased (P &lt; .05) in the infants receiving furosemide. The diuresis seemed to have no effect on left atrial size determined echocardiographically, whereas measurements of dynamic skinfold thickness suggested mobilization of subcutaneous water. One infant became seriously dehydrated and hypotensive secondary to a massive diuresis. We concluded that furosemide had a potent diuretic effect in infants with hyaline membrane disease but does not improve cardiorespiratory function acutely. This may be because of failure to mobilize pulmonary interstitial fluid in the time period tested. It may also be possible that the presence of pulmonary interstitial fluid does not play an important role in the impairment of gas exchange in the acute stage of hyaline membrane disease.

scholarly journals Platypnoea–orthodeoxia after left total knee replacement

2019 ◽  
Vol 12 (10) ◽  
pp. e230771
Author(s):  
Taha Almufti ◽  
Franz Eversheim ◽  
Brett Johnson ◽  
Gabriel Ayonmigbesimi Akra
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Unusual Case ◽  
Medical Intervention ◽  
Colour Doppler ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Significant Difference ◽  
Severe Hypoxaemia ◽  
Total Knee

Platypnoea–orthodeoxia syndrome (POS) is a rare disorder characterised by both dyspnoea (platypnoea) and arterial desaturation (orthodeoxia) in the upright position, with improvement in the supine position. We report an unusual case in which an 82-year-old woman developed severe hypoxaemia with POS after left total knee replacement. A significant difference in alveolar–arterial blood gas oxygen tension was demonstrated, and hypoxaemia failed to respond to 100% oxygen supply. A patent foramen ovale with a right-to-left shunt was evident on transoesophageal echocardiogram employing colour Doppler and agitated normal saline studies. Interestingly, the patient’s symptoms resolved within 6 months with ongoing chest physiotherapy, without surgical or medical intervention.

Effects of tracheal occlusion on the neonatal cardiopulmonary transition in an ovine model of diaphragmatic hernia

2019 ◽  
Vol 104 (6) ◽  
pp. F609-F616 ◽  
Author(s):  
Philip L J DeKoninck ◽  
Kelly J Crossley ◽  
Aidan J Kashyap ◽  
Sasha M Skinner ◽  
Marta Thio ◽  
...  
Keyword(s):  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Diaphragmatic Hernia ◽  
Weight Ratio ◽  
Lung Compliance ◽  
Ovine Model ◽  
Lung Weight ◽  
Tracheal Occlusion ◽  
Arterial Blood Gas ◽  
Arterial Blood

ObjectiveFetoscopic endoluminal tracheal occlusion (FETO) aims to reverse pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) and mitigate the associated respiratory insufficiency and pulmonary hypertension after birth. We aimed to determine whether FETO improves the cardiopulmonary transition at birth in an ovine model of CDH.MethodsIn 12 ovine fetuses with surgically induced diaphragmatic hernia (DH; 80 dGA), an endotracheal balloon was placed tracheoscopically at ≈110 dGA and removed at ≈131 dGA (DH+FETO), while 10 were left untreated (DH). At ≈138 dGA, all lambs (survival at delivery: 67% [DH+FETO], 70% [DH]) were delivered via caesarean section and ventilated for 2 hours. Physiological and ventilation parameters were continuously recorded, and arterial blood-gas values were measured.ResultsCompared with DH, DH+FETO lambs had increased wet lung-to-body-weight ratio (0.031±0.004 vs 0.016±0.002) and dynamic lung compliance (0.7±0.1 vs 0.4±0.1 mL/cmH2O). Pulmonary vascular resistance was lower in DH+FETO lambs (0.44±0.11 vs 1.06±0.17 mm Hg/[mL/min]). However, after correction for lung weight, pulmonary blood flow was not significantly different between the groups (4.19±0.57 vs 4.05±0.60 mL/min/g). Alveolar–arterial difference in oxygen tension was not significantly different between DH+FETO and DH (402±41mm Hg vs 401±45 mm Hg).ConclusionsFETO accelerated lung growth in fetuses with CDH and improved neonatal respiratory function during the cardiopulmonary transition at birth. However, despite improved lung compliance and reduced pulmonary vascular resistance, there were less pronounced benefits for gas exchange during the first 2 hours of life.

Effects of chest compression on reflex ventilatory drive and pulmonary function

1962 ◽  
Vol 17 (4) ◽  
pp. 701-705 ◽  
Author(s):  
Malcolm B. McIlroy ◽  
John Butler ◽  
Theodore N. Finley
Keyword(s):  
Chest Compression ◽  
Lung Volume ◽  
Transpulmonary Pressure ◽  
Normal Subjects ◽  
Lung Compliance ◽  
External Compression ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Ventilatory Drive ◽  
Anatomical Dead Space

External compression of the chest sufficient to reduce the lung volume (FRC) by 1 liter in eight normal subjects interfered with the mechanical function of the lungs. We have confirmed the findings of Caro et al. ( J. Clin. Invest. 39: 573, 1960), who showed a decrease in lung compliance and an increase in respiratory rate. Neither returned to normal when the compressing force was removed, and it was not until the subject took a deep breath that the lungs returned to their control state. We also found a reduction in anatomical dead space and alveolar hyperventilation. Arterial blood gas tensions showed evidence of complex ventilation-perfusion abnormalities, which could not be explained by any single factor. We think the hyperventilation associated with chest compression is reflex in origin and related to a decrease in lung volume rather than to any change in transpulmonary pressure. Submitted on January 4, 1962

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