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King MR, Feldman JM. Optimal management of apparatus dead space in the anesthetized infant. Paediatr Anaesth 2017; 27:1185-1192. [PMID: 29044830 DOI: 10.1111/pan.13254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/23/2017] [Indexed: 11/28/2022]
Abstract
Mechanical ventilation of the anesthetized infant requires careful attention to equipment and ventilator settings to assure optimal gas exchange and minimize the potential for lung injury. Apparatus dead space, defined as dead space resulting from devices placed between the endotracheal tube and the Y-piece of the breathing circuit, is the primary source of dead space controlled by the clinician. Due to the small tidal volumes required by infants and neonates, it is easy to create excessive apparatus dead space resulting in unintended hypercarbia or increased minute ventilation in an effort to achieve a desirable PCO2 . The goal of this review was to evaluate the apparatus that are commonly added to the breathing circuit during anesthesia care, and develop recommendations to guide the clinician in selecting apparatus that are best matched to the clinical goals and the patient's size. We include specific recommendations for apparatus that are best suited for different size pediatric patients, with a particular focus on patients <5 kg.
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Affiliation(s)
- Michael R King
- Ann and Robert H. Lurie Children's Hospital of Chicago and Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Jeffrey M Feldman
- The Children's Hospital of Philadelphia and the University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
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Biscardi FH, Rubio ER. Transtracheal oxygen and positive airway pressure: A salvage technique in overlap syndrome. Lung India 2014; 31:67-9. [PMID: 24669088 PMCID: PMC3960816 DOI: 10.4103/0970-2113.125988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The coexistence of sleep apnea-hypopnea syndrome (SAHS) with chronic obstructive pulmonary disease (COPD) occurs commonly. This so called overlap syndrome leads to more profound hypoxemia, hypercapnic respiratory failure, and pulmonary hypertension than each of these conditions independently. Not infrequently, these patients show profound hypoxemia, despite optimal continuous positive airway pressure (CPAP) therapy for their SAHS. We report a case where CPAP therapy with additional in-line oxygen supplementation failed to accomplish adequate oxygenation. Adding transtracheal oxygen therapy (TTOT) to CPAP therapy provided better results. We review the literature on transtracheal oxygen therapy and how this technique may play a significant role in these complicated patients with overlap syndrome, obviating the need for more invasive procedures, such as tracheostomy.
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Affiliation(s)
- Frank Hugo Biscardi
- Section of Pulmonary Medicine, Critical Care and Sleep Disorders, Department of Internal Medicine, Virginia Tech Carilion, School of Medicine and Research Institute, Roanoke, Virginia, USA ; Roanoke Memorial, Roanoke, Virginia, USA ; Stonewall Jackson Hospital Sleep Centers, Roanoke, Virginia, USA
| | - Edmundo Raul Rubio
- Section of Pulmonary Medicine, Critical Care and Sleep Disorders, Department of Internal Medicine, Virginia Tech Carilion, School of Medicine and Research Institute, Roanoke, Virginia, USA
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Abstract
Transtracheal gas insufflation (TGI) improves gas exchange efficiency, but is associated with hyperinflation, and usually requires ventilator adjustment to compensate for the increased gas flow. Although bidirectional TGI (Bi-TGI) minimizes hyperinflation, it does not preclude the need to reduce tidal volumes to prevent hyperinflation. A flow-compensation system was developed by Respironics (Murrysville, PA) to match TGI flows; however, neither that nor the efficacy of Bi-TGI have been tested in vivo. We tested the hypotheses that flow compensation allows for a constant minute ventilation; Bi-TGI produces less hyperinflation than does unidirectional TGI (Uni-TGI), and endotracheal tube size influences the degree of hyperinflation during TGI. Seven anesthetized intact dogs were studied during positive-pressure ventilation using the Respironics flow compensation system. Measurements were made during steady-state conditions at constant and measured levels of CO(2) production. Gas exchange efficiency (assessed by expired gas analysis for dead space) and hyperinflation (measured as an increase in pleural pressure) were compared during Bi- and Uni-TGI and for endotracheal tube sizes varying from 7 to 10F. Bi- and Uni-TGI could be delivered at constant minute ventilation without adjusting ventilatory setting when the flow compensation circuit was present. Uni-TGI produced more hyperinflation than did Bi-TGI with all sizes of endotracheal tube, and hyperinflation was universally present as tube size decreased to 7.5F. We conclude that this new flow compensation system allows for the delivery of TGI without the need for adjustments to the ventilator settings, and that Bi-TGI produces less hyperinflation than does Uni-TGI, even with small diameter endotracheal tubes.
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Affiliation(s)
- Michael R Pinsky
- Cardiopulmonary Research Laboratory, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
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Brack T, Senn O, Russi EW, Bloch KE. Transtracheal high-flow insufflation supports spontaneous respiration in chronic respiratory failure. Chest 2005; 127:98-104. [PMID: 15653968 DOI: 10.1378/chest.127.1.98] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
STUDY OBJECTIVES Transtracheal insufflation of oxygen-enriched air at a high flow rate has been proposed to support ventilation. The purpose of this study was to investigate the physiologic effects of high-flow insufflation unobtrusively with a respiratory inductive plethysmograph in patients with chronic respiratory failure. Using a respiratory inductive plethysmograph also permitted monitoring of end-expiratory lung volume, and respiratory variables could be quantified independently of the tracheal bias flow. DESIGN Prospective randomized comparison of low-flow vs high-flow transtracheal insufflation. SETTING Pulmonary division of a tertiary teaching hospital. PATIENTS Fourteen spontaneously breathing outpatients with chronic hypoxemic respiratory failure carrying a transtracheal catheter for long-term oxygen therapy. INTERVENTIONS AND MEASUREMENTS Oxygen-enriched air (fraction of inspired oxygen, 0.37) at 15 L/min and oxygen at 1.5 L/min were transtracheally administered for 1 h each. The breathing pattern and the end-expiratory lung volume were monitored by inductive plethysmography along with pulse oximetry and transcutaneous PCO2. Arterial blood gases were also analyzed at the end of the hour of both low-flow and high-flow insufflation. RESULTS High-flow insufflation decreased the mean (+/- SEM) minute ventilation (Ve) by 20% from 8.37 +/- 0.49 to 6.66 +/- 0.57 L/min, the mean respiratory rate from 19.2 +/- 0.9 to 15.7 +/- 1.0 breaths/min, while mean expiratory time increased from 2.0 +/- 0.1 to 2.8 +/- 0.2 s, and end-expiratory lung volume decreased by 0.55 +/- 0.15 L compared to low-flow oxygen insufflation (p < 0.05 for all comparisons). Mean arterial and transcutaneous PCO2 decreased from 45 +/- 1 to 43 +/- 1 mm Hg and from 54 +/- 2 to 53 +/- 2 mm Hg, respectively (p < 0.05 in both instances), while arterial PaO2 and oxygen saturation did not change. CONCLUSIONS High-flow transtracheal insufflation of oxygen-enriched air assists ventilation by reducing Ve without compromising gas exchange and by reducing end-expiratory lung volume, possibly through the reversal of dynamic hyperinflation.
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Affiliation(s)
- Thomas Brack
- Division of Pulmonary Medicine, University Hospital, Zürich, Switzerland.
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Darwish RS, Gilbert TB, Fahy BG. Management of a bronchopleural fistula using differential lung airway pressure release ventilation. J Cardiothorac Vasc Anesth 2003; 17:744-6. [PMID: 14689418 DOI: 10.1053/j.jvca.2003.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ribal S Darwish
- Department of Anesthesiology, University of Maryland School of Medicine, Suite S8B00, 22 South Greene Street, Baltimore, MD 21201-1595, USA.
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Abstract
Over the past 20 years a variety of transtracheal catheters have been developed for long-term oxygen therapy. A modified Seldinger technique has been the standard in the past, but a more recent procedure for surgical creation of the tracheocutaneous tract presents a number of potential advantages. TTO should be administered as a program of care, and recent advances with a streamlined and shortened program have simplified and improved the delivery of a technology that has a number of potential benefits and established safety. TTO may further increase the oxygen conservation efficiency of demand oxygen controller devices, and studies have shown TTO to be a potential alternative to nasal oxygen, continuous positive airway pressure, and tracheotomy for severe obstructive sleep apnea. Very high flows (> 10 L/minute) of a humidified air/oxygen blend, termed transtracheal augmented ventilation, extend the physiologic benefits of TTO and have promise in both the outpatient nocturnal ventilatory support of patients with severe respiratory disease and in liberation of patients from prolonged mechanical ventilation.
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Hoffman LA, Tasota FJ, Delgado E, Zullo TG, Pinsky MR. Effect of Tracheal Gas Insufflation During Weaning From Prolonged Mechanical Ventilation: A Preliminary Study. Am J Crit Care 2003. [DOI: 10.4037/ajcc2003.12.1.31] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
• Background Tracheal gas insufflation reduces inspired tidal volume and minute ventilation in spontaneously breathing patients and may facilitate weaning from mechanical ventilation.• Objective To determine if tracheal gas insufflation can reduce ventilatory demand during weaning trials in patients who require prolonged mechanical ventilation.• Methods A reduction in ventilatory demand was defined as a relative decrease in tidal volume, minute ventilation, and mean inspiratory flow during trials with tracheal gas insufflation compared with the values during trials without this therapy. A total of 14 subjects underwent T-piece trials with and without insufflation (flow rate 6 L/min) on 2 consecutive days; the order of insufflation was randomized. Tidal volume, minute ventilation, and mean inspiratory flow were measured at baseline (without insufflation) and 2 hours later.• Results Differences in ventilatory demand were not significant when comparisons were made for condition (tracheal gas insufflation vs no flow) or time (baseline vs 2 hours) for the total group (P = .48). Subjects were classified post hoc as responders (n = 9) or nonresponders (n = 5). Comparisons between responders and nonresponders indicated a significant (P = .02) 3-way multivariate interaction for group (responder vs nonresponder), condition (tracheal gas insufflation vs no flow), and time (baseline vs 2 hours) for ventilatory demand variables.• Conclusion Tracheal gas insufflation can reduce ventilatory demand during weaning trials in some patients who require mechanical ventilation.
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Affiliation(s)
- Leslie A. Hoffman
- Department of Acute/Tertiary Care, University of Pittsburgh School of Nursing (LAH, FJT, TGZ), and Respiratory Care (ED) and Department of Critical Care Medicine (MRP), University of Pittsburgh Medical Center, Pittsburgh, Pa
| | - Frederick J. Tasota
- Department of Acute/Tertiary Care, University of Pittsburgh School of Nursing (LAH, FJT, TGZ), and Respiratory Care (ED) and Department of Critical Care Medicine (MRP), University of Pittsburgh Medical Center, Pittsburgh, Pa
| | - Edgar Delgado
- Department of Acute/Tertiary Care, University of Pittsburgh School of Nursing (LAH, FJT, TGZ), and Respiratory Care (ED) and Department of Critical Care Medicine (MRP), University of Pittsburgh Medical Center, Pittsburgh, Pa
| | - Thomas G. Zullo
- Department of Acute/Tertiary Care, University of Pittsburgh School of Nursing (LAH, FJT, TGZ), and Respiratory Care (ED) and Department of Critical Care Medicine (MRP), University of Pittsburgh Medical Center, Pittsburgh, Pa
| | - Michael R. Pinsky
- Department of Acute/Tertiary Care, University of Pittsburgh School of Nursing (LAH, FJT, TGZ), and Respiratory Care (ED) and Department of Critical Care Medicine (MRP), University of Pittsburgh Medical Center, Pittsburgh, Pa
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Tagaito Y, Schneider H, O'Donnell CP, Smith PL, Schwartz AR. Ventilating with tracheal gas insufflation and periodic tracheal occlusion during sleep and wakefulness. Chest 2002; 122:1742-50. [PMID: 12426280 DOI: 10.1378/chest.122.5.1742] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
INTRODUCTION The current invasive and noninvasive methods for delivering long-term ventilatory support rely on cumbersome patient interfaces that may interfere with upper airway function. To overcome these limitations, a novel system was developed to ventilate conscious, spontaneously breathing dogs through a self-contained cuffed cannula that was used for tracheal gas insufflation (TGI) and periodic tracheal occlusion (PTO). We hypothesized that TGI + PTO would provide greater ventilatory support than would TGI alone and that its effect would be more pronounced during sleep than wakefulness. METHODS Chronically tracheostomized dogs were monitored for sleep (ie, EEG, electro- oculogram, and nuchal electromyogram) and breathing (ie, tracheal pressure [Ptr] and upper airway flow via snout mask). A thin transtracheal cannula housed within a cuffed tracheostomy tube was used for TGI and PTO monitoring. E, gas exchange, and breathing patterns were examined during sleep and wakefulness at baseline (ie, no TGI) and during the application of TGI alone (at 5, 10, and 15 L/min) and the application of TGI + PTO. RESULTS Compared to baseline breathing without TGI, TGI at 5, 10, and 15 L/min decreased minute ventilation without influencing PaCO(2). In contrast, TGI + PTO led to progressive increases in ventilation, positive Ptr swings, and decreases in PaCO(2) as the flow rate was increased during sleep and wakefulness. Moreover, spontaneous breathing efforts ceased during TGI + PTO at flow rates of 10 and 15 L/min during wakefulness, and at all flow rates during sleep. CONCLUSIONS The findings indicate that TGI + PTO can fully support ventilation in a spontaneously breathing canine model during sleep and wakefulness. Its streamlined interface could ultimately prove to be clinically significant, once technical concerns are addressed.
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Affiliation(s)
- Y Tagaito
- Department of Anesthesiology, Chiba University School of Medicine, Chiba, Japan
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Abstract
Tracheal gas insufflation is a technique in which gas is injected intratracheally during positive pressure ventilation. The fresh gas rinses expired gas from the tracheal tube and anatomical dead space, aiding carbon dioxide elimination. This reduces ventilatory volume and pressure, helping to reduce ventilator-induced lung damage. Complications of tracheal gas insufflation include interference with ventilator function, tracheal damage and barotrauma. Expiratory washout is a variation of tracheal gas insufflation. We designed and constructed an original expiratory washout system and evaluated its safety and performance in lung and animal models. We found that expiratory limb and tracheal tube occlusion tests caused the device to disable itself at acceptable intratracheal pressures. We also demonstrated up to 31% reduction in tidal volume compared with conventional ventilation, supporting the possibility of using this device clinically to lessen volutrauma. We concluded that aspects of this design might alleviate many of the safety concerns of using tracheal gas insufflation.
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Affiliation(s)
- J Dingley
- Department of Anaesthesia, The Cardiac Centre, Morriston Hospital, Swansea SA6 6NL, UK.
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Rossi N, Musch G, Sangalli F, Verweij M, Patroniti N, Fumagalli R, Pesenti A. Reverse-thrust ventilation in hypercapnic patients with acute respiratory distress syndrome. Acute physiological effects. Am J Respir Crit Care Med 2000; 162:363-8. [PMID: 10934054 DOI: 10.1164/ajrccm.162.2.9908024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Techniques of tracheal gas insufflation (TGI) have been shown to enhance CO(2) clearance efficiency in mechanically ventilated patients with acute respiratory distress syndrome (ARDS). Clinical studies have explored the effects of such techniques only at moderate intratracheal gas flow rates, with TGI superimposed to mechanical ventilation in a continuous fashion, or synchronized to the expiratory phase of the duty cycle. We examined the effects of intratracheal pulmonary ventilation (ITPV), delivering the entire tidal volume (VT) in the proximity of the tracheal carina, with all the gas flow supplied continuously through a reverse-thrust catheter (RTC). A potential limitation in the application of TGI is dynamic hyperinflation. Therefore, in a subgroup of patients, we also evaluated the effects of ITPV on end-expiratory lung volume (EELV) by respiratory inductive plethysmography (RIP). Eleven patients with ARDS under volume-cycled mechanical ventilation were subsequently switched to ITPV at the same baseline respiratory rate, I:E ratio, and VT. At the same minute volume, Pa(CO(2)) decreased from 70 +/- 12.3 to 59 +/- 9.5 mm Hg, with a percent reduction of 15 +/- 4% (range from 10 to 20%). The CO(2) decrease was greater in patients with higher baseline Pa(CO(2)) levels (DeltaPa(CO(2)) = 0.29 x Pa(CO(2)) - 9.48, r = 0.95). During transition from mechanical ventilation to ITPV, tracheal positive end-expiratory pressure (PEEP(tr)) decreased with a correspondent decrease in EELV. Both were restored by increasing the PEEP at the ventilator by 3.6 +/- 2.0 cm H(2)O. These data suggest that in patients with ARDS ITPV effectively reduces dead space ventilation and the employment of the RTC may limit or avoid dynamic hyperinflation.
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Affiliation(s)
- N Rossi
- Department of Anesthesia and Intensive Care, Ospedale San Gerardo Nuovo dei Tintori, University of Milan, Monza, Milan, Italy.
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Abstract
Tracheal insufflation of oxygen has at least three major uses for chronic oxygen supplementation through a percutaneous catheter, it is an adjunctive measure to enhance gas exchange during mechanical ventilation, and it provides an emergency therapy for oxygen delivery with upper airway obstruction. In this article the mechanisms of gas exchange and techniques of oxygen delivery are described for each of these major uses.
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Affiliation(s)
- D M Eckmann
- Department of Anesthesia, University of Pennsylvania School of Medicine, Philadelphia, USA.
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Dorne R, Liron L, Pommier C. [Tracheal gas insufflation associated with mechanical ventilation for CO2 removal]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 2000; 19:115-27. [PMID: 10730175 DOI: 10.1016/s0750-7658(00)00110-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Tracheal gas insufflation (TGI) either continuously, or at inspiration, or at expiration, is a technique associated with mechanical ventilation aimed to enhance CO2 elimination in favouring washout of anatomical dead space. This article analyses the mechanism of action, the techniques and the effects of TGI in presence of hypercapnia, especially in the fame of ARDS in adults. DATA SOURCES In addition to some historical or major references, the articles on TGI published over the past five years have been searched in the Medline data base. STUDY SELECTION Articles with data on TGI associated with mechanical ventilation were selected. DATA EXTRACTION Data on mechanisms of action, technical and practical aspects of TGI were extracted. DATA SYNTHESIS CO2 elimination is increased when the TGI catheter tip is close to the carina, when the gas jet is directed towards the latter, by a continuous gas jet, by a high washing gas volume. The effect on oxygenation is minor. The work of breathing is decreased. An increased intracranial pressure is decreased. Circulatory effects are minor. The major risk is dynamic pulmonary over distension. Local complications include dessiccation and lesion of bronchial mucosa by the gas jet. CONCLUSION In mechanically ventilated patients, additional TGI is a valuable technique for decreasing anatomical dead space. TGI decreases hypercapnia during mechanical ventilation with limited tidal volumes in permissive hypercapnia. Further clinical studies with large series of patients are required to assess the benefits and the effect of TGI on outcome.
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Affiliation(s)
- R Dorne
- Service de réanimation polyvalente, centre hospitalier Saint-Joseph et Saint-Luc, Lyon, France
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Cereda MF, Sparacino ME, Frank AR, Trawöger R, Kolobow T. Efficacy of tracheal gas insufflation in spontaneously breathing sheep with lung injury. Am J Respir Crit Care Med 1999; 159:845-50. [PMID: 10051261 DOI: 10.1164/ajrccm.159.3.9801126] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Tracheal gas insufflation (TGI) decreases dead space (V D) and can be combined with continuous positive airway pressure (CPAP) to decrease minute volume (VE) and effort of breathing. In 11 anesthetized sheep, we induced acute lung injury (ALI) through oleic acid (OA) infusion and studied the effects of TGI combined with CPAP (CPAP-TGI) at different TGI flows and with catheters of different designs. Sheep were randomized to two groups: Group A (n = 7) was placed on CPAP and CPAP-TGI at 10 and 15 L/min of insufflation flow delivered through a reverse thrust catheter (RTC). Group B (n = 4) was placed on CPAP and CPAP-TGI at a flow of 10 L/min delivered through a RTC, and through a straight flow catheter (SFC). Compared with CPAP alone, CPAP-TGI resulted in significantly lower VD, VE, pressure time product, and work of breathing. We found no additional benefit from TGI flow of 15 L/min, compared with 10 L/min, and no statistically significant difference between the SFC and the RTC. In conclusion, TGI can be combined with CPAP in this model of ALI to reduce ventilation and effort of breathing.
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Affiliation(s)
- M F Cereda
- Section on Pulmonary and Cardiac Assist Devices, Pulmonary and Critical Care Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
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Giacomini M, Kolobow T, Reali-Forster C, Trawöger R, Cereda M. Intratracheal pulmonary ventilation and continuous positive airway pressure in a sheep model of severe acute respiratory failure. Chest 1997; 112:1060-7. [PMID: 9377918 DOI: 10.1378/chest.112.4.1060] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
STUDY OBJECTIVES Previously we have shown that optimal pulmonary gas exchange can be sustained at normal airway pressures in a model of severe acute respiratory failure (ARF), using intratracheal pulmonary ventilation (ITPV), with weaning to room air. In an identical model of ARF, we have now explored whether ITPV, combined with continuous positive airway pressure (CPAP), can sustain adequate ventilation, with weaning to room air. DESIGN Randomized study in sheep. SETTING Animal research laboratory at the National Institutes of Health. INTERVENTIONS ARF was induced in 12 sheep, using mechanical ventilation at peak inspiratory pressure of 50 cm H2O, but excluding 5 to 8% of lungs. Sheep were then randomized into two groups: the CPAP-ITPV group (n=6), in which ITPV was combined with a novel CPAP system; and a control group (n=6) in which the same CPAP circuit was used, but without ITPV. MEASUREMENTS AND RESULTS All sheep in the CPAP-ITPV group were weaned to room air in 38.7+/-14 h. PaO2/fraction of inspired oxygen (FIO2) progressively increased from 108.8+/-43 to 355.7+/-93.1; PaCO2 remained within normal range; respiratory rate (RR) ranged from 18 to 120 breaths/min, and tidal volume (VT) was as low as 1.1 mL/kg. All sheep in the control group (CPAP alone) developed severe respiratory acidosis and hypoxemia after 4.8+/-4 h. PaO2/FIO2 decreased from 126.6+/-58.2 to 107.2+/-52.5 mm Hg, with a final PaCO2 of 166.8+/-73.3 mm Hg. CONCLUSIONS All sheep treated with CPAP-ITPV maintained good gas exchange without hypercapnia at high RR and at low VT, with weaning to room air. All control animals treated with CPAP alone developed severe hypercapnia, respiratory acidosis, and severe hypoxemia, and were killed.
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Affiliation(s)
- M Giacomini
- Pulmonary-Critical Care Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md 20892-1590, USA
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Finocchiaro C, Lark A, Keating M, Ugoni A, Abramson M. Does occupational exposure to brown coal dust cause a decline in lung function? Occup Environ Med 1997; 54:642-5. [PMID: 9423576 PMCID: PMC1128837 DOI: 10.1136/oem.54.9.642] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES To determine if the rate of change in forced expiratory volume in one second (FEV1) in subjects with high exposure to Latrobe Valley brown coal dust was significantly greater than the rate of change among subjects with low exposure. METHODS A retrospective dynamic cohort design with variable time windows. This study was conducted over a period of 14 years from 1980 to 1994 and used data collected by the State Electricity Commission (SEC) Lung Function Unit for an asbestos surveillance programme. The subjects were exposed to low, medium, or high levels of coal dust. Basic spirometry with wedge bellows spirometers was used to assess lung function. A general linear model (GLM) was used to assess the effects of smoking and exposure to coal dust upon the change in forced expiratory volume in one second (FEV1) while adjusting for age and height. RESULTS The mean (95% confidence interval (95% CI) rate of decline in FEV1 was 40 (36 to 44) ml/year. Age was a significant predictor of change. A significant effect was found for smoking (P = 0.02) and for exposure to coal dust (P = 0.008). The only significant difference with exposure to coal dust was between the high and mixed exposure categories. CONCLUSION There is no convincing evidence of excessive decline in FEV1 with exposure to coal dust > 0.75 mg/m3. The absence of a dose response relation provides some evidence against a causal relation. On the basis of this study, reduction of the exposure standards currently applied to brown coal dust in the Victorian electricity industry is not warranted to prevent respiratory disease.
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Affiliation(s)
- C Finocchiaro
- Department of Epidemiology and Preventive Medicine, Monash University, Prahran, Victoria, Australia
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Meszaros E, Ogawa R. Continuous low-flow tracheal gas insufflation during partial liquid ventilation in rabbits. Acta Anaesthesiol Scand 1997; 41:861-7. [PMID: 9265929 DOI: 10.1111/j.1399-6576.1997.tb04801.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Both partial liquid ventilation (PLV) and tracheal gas insufflation are novel techniques for mechanical ventilation. In this study we examined whether PLV superimposed by continuous low-flow tracheal gas insufflation (TGI) offers any advantage to the blood gases and lung mechanics in normal-lung rabbits compared to the use of PLV only. METHODS Eighteen anesthetized, paralyzed and mechanically ventilated rabbits were used. After obtaining a baseline PaCO2 value between 29 and 39 mmHg (3.9 and 5.2 kPa), the animals were assigned to three equal groups according to the ventilation they received--A group: PLV superimposed by TGI; B group: PLV only; and C group: continuous mandatory ventilation (CMV) superimposed by TGI. Serial arterial blood gases, pH and lung mechanics were measured. RESULTS The animals in each group were hemodynamically stable. In the case of the A group, PaO2 continuously increased, and PaCO2 stabilized around 40.8 +/- 5.5 mmHg (5.4 +/- 0.7 kPa, mean +/- SD, NS). In the B group, the tendency for PaO2 to increase was not as definite; PaCO2 continuously increased from 35.2 +/- 2.3 mmHg (4.7 +/- 0.3 kPa) to 56.3 +/- 12.7 mmHg (7.5 +/- 1.7 kPa, P < 0.05) at the end of the experiment. In the C group, PaO2 and PaCO2 were stable during the observation period. The superimposition of TGI on PLV did not decrease the airway pressures compared to PLV alone. CONCLUSION In summary, continuous low-flow TGI superimposed on PLV can decrease and stabilize the PaCO2 elevation caused by the initiation of PLV.
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Affiliation(s)
- E Meszaros
- Department of Anesthesiology, Nippon Medical School, Tokyo, Japan
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Okamoto K, Kishi H, Choi H, Sato T. Combination of tracheal gas insufflation and airway pressure release ventilation. Chest 1997; 111:1366-74. [PMID: 9149596 DOI: 10.1378/chest.111.5.1366] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
STUDY OBJECTIVE We hypothesized that the continuous gas flow administration delivered through an insufflation catheter positioned above the carina during airway pressure release ventilation (APRV) would facilitate carbon dioxide (CO2) elimination, resulting in normocarbia with a substantially reduced peak airway pressure (Paw). To test this hypothesis, we compared intermittent positive pressure ventilation (IPPV), tracheal gas insufflation (TGI), APRV, and combined TGI and APRV (TGI + APRV). DESIGN Animal study with random application of four ventilatory modes in a canine restrictive-thorax model with and without pulmonary edema. SETTING Research laboratory at Kumamoto (Japan) University School of Medicine. SUBJECTS Six mongrel dogs. INTERVENTIONS Application of four ventilatory modes (IPPV, TGI, APRV, and TGI + APRV). MEASUREMENTS AND RESULTS TGI + APRV facilitated CO2 elimination. The peak Paw was significantly lower during TGI + APRV than during IPPV (nonpulmonary edema model; 15 +/- 4 vs 28 +/- 9 cm H2O; p < 0.05; pulmonary edema model: 20 +/- 4 vs 34 +/- 10 cm H2O; p < 0.05). Normocarbia was observed in both models. Neither TGI nor APRV alone maintained normocarbia. CONCLUSION The combined use of TGI and APRV is a more effective method of maintaining normocarbia with reduced peak Paw than either IPPV or APRV alone.
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Affiliation(s)
- K Okamoto
- Department of Anesthesiology, Kumamoto University School of Medicine, Japan
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Miro AM, Hoffman LA, Tasota FJ, Sigler DW, Gowski DT, Lutz J, Zullo T, Pinsky MR. Tracheal gas insufflation improves ventilatory efficiency during metacholine-induced bronchospasm. J Crit Care 1997; 12:13-21. [PMID: 9075060 DOI: 10.1016/s0883-9441(97)90021-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Barotrauma and cardiovascular insufficiency are frequently encountered problems in patients with acute bronchospastic disease who require mechanical ventilation. Permissive hypercapnia is a recognized strategy for minimizing these adverse effects; however, it has potential risks. Tracheal gas insufflation (TGI) has been shown to increase carbon dioxide elimination efficiency and thus could permit mechanical ventilation at lower peak airway pressures without inducing hypercapnia. However, caution exists as to the impact of TGI on lung volumes, given that expiratory flow limitation is a hallmark of bronchospastic disease. PURPOSE To examine these issues, we studied ventilatory and hemodynamic effects of continuous TGI as an adjunct to mechanical ventilation before and after methacholine-induced bronchospasm. MATERIALS AND METHODS Ten anesthetized, paralyzed dogs were ventilated on volume-controlled mechanical ventilation during administration of continuous TGI (0, 2, 6, and 10 L/min) while total inspired minute ventilation (ventilator-derived minute ventilation plus TGI) was kept constant. In an additional step, with TGI flow of 10 L/min, total inspired minute ventilation was decreased by 30%. RESULTS PaCO2 decreased (44 +/- 7 mm Hg at zero flow to 34 +/- 7 mm Hg at 6 L/min and 31 +/- 6 mm Hg at 10 L/min, respectively, P < .05), as did the dead space to tidal volume ratio at TGI of 6 and 10 L/min compared with zero flow. There were no significant changes in end-expiratory transpulmonary pressure, mean arterial pressure, or cardiac output. During the highest TGI flow (10 L/min), with a 30% reduction of total inspired minute ventilation, both PaCO2 and peak airway pressure remained less than during zero flow conditions. CONCLUSION We conclude that TGI increases carbon dioxide elimination efficiency during constant and decreased minute ventilation conditions without any evidence of hyperinflation or hemodynamic instability during methacholine-induced bronchospasm.
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Affiliation(s)
- A M Miro
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Pittsburgh, PA 15261, USA
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Gowski DT, Delgado E, Miro AM, Tasota FJ, Hoffman LA, Pinsky MR. Tracheal gas insufflation during pressure-control ventilation: effect of using a pressure relief valve. Crit Care Med 1997; 25:145-52. [PMID: 8989191 DOI: 10.1097/00003246-199701000-00027] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVES Pressure-control ventilation minimizes alveolar overdistention by limiting peak airway pressure, but a consequence of this pressure limitation may be a reduction in tidal volume with subsequent hypercarbia. Tracheal gas insufflation (TGI) can be used in combination with pressure-control ventilation to augment CO2 elimination. During pressure-control ventilation with continuous TGI, we observed that peak airway pressure increased above the set inspiratory pressure. Based on this observation, we investigated the ability of the pressure-control ventilator circuit to compensate for continuous TGI and the effect of insertion of a pressure relief valve to eliminate over-pressurization. SETTING University research laboratory. DESIGN Using an artificial lung model, we studied the effects of continuous TGI with varying catheter flows (0, 2, 6, and 10 L/ min); ventilator frequencies (10 and 20 breaths/min); inspiratory duty cycles (0.33, 0.50, and 0.67); lung compliance (0.01, 0.02, and 0.04 L/cm H2O); and airway resistance (5, 20, and 50 cm H2O/L/sec) on: a) peak airway pressure; b) total inspiratory tidal volume; c) ventilator-derived tidal volume; and d) intrapulmonary pressure at end-exhalation (auto-PEEP). Tests were performed with and without a pressure relief valve whose threshold "pop-off" pressure was adjusted to match the set inspiratory pressure (35 cm H2O) for a total of 432 experimental conditions. MEASUREMENTS AND MAIN RESULTS Our data demonstrate that pressure-control ventilation augmented with continuous TGI can increase peak airway pressure above set inspiratory pressure due to delivery of a higher than intended tidal volume. Predisposing conditions include catheter flow rates of 6 and 10 L/min, long inspiratory time, low compliance, and low resistance. With the pressure relief valve, peak airway pressure was maintained at the set inspiratory pressure and total inspiratory tidal volume remained constant. CONCLUSION A pressure relief valve is a necessary adjunct to maintain peak airway pressure at set inspiratory pressure and keep total inspiratory tidal volume constant when continuous TGI is administered in conjunction with pressure-control ventilation.
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Affiliation(s)
- D T Gowski
- Department of Anesthesiology, School of Medicine, University of Pittsburgh, USA
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Andrivet P, Richard G, Viau F, Letinier JY, Darne C, Vu Ngoc C. Treatment of respiratory failure using minitracheotomy and intratracheal oxygenation in selected patients with chronic lung disease. Intensive Care Med 1996; 22:1323-7. [PMID: 8986480 DOI: 10.1007/bf01709545] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To evaluate the efficacy of minitracheotomy (MT) insertion for intratracheal oxygen insufflation (ITO2) on arterial blood gases and survival in patients with respiratory failure from chronic lung disease. DESIGN Open, prospective clinical study. SETTING A 12-bed medical intensive care unit in a non-university hospital. PATIENTS 20 patients (14 males and 6 females, mean age 74.8 +/- 2.6 years), admitted for respiratory failure and denied mechanical ventilation. INTERVENTION Percutaneous insertion of an MT for ITO2. Arterial blood gases were drawn just prior to, then 3, 24, 48 h and 1 week after MT insertion. Data are evaluated with a two-way analysis of variance for distribution-free data (Friedman's rank sums test). MEASUREMENTS AND RESULTS Three hours after starting ITO2, the partial pressure of oxygen in arterial blood (PaO2) and the arterial oxygen saturation (SaO2) both increased from 51.7 +/- 2.8 to 85.4 +/- 5.6 mmHg and from 79.7 +/- 3.1 to 93.7 +/- 0.9%, respectively (p < 0.001 for both), along with a slight worsening in the partial pressure of carbon dioxide in arterial blood (PaCO2), from 59.6 +/- 2.5 to 63.5 +/- 3.0 mmHg (p < 0.05). At 1 week, improvements in PaO2 and SaO2 were maintained in all patients, while PaCO2 decreased in 14 patients (mean decrease 8.3 mmHg) and increased in the remaining patients (mean 12.5 mmHg), when compared to pre-ITO2 values. Seven patients died during follow-up, leading to a success rate of 65%. Eight and 4 patients were discharged home and to a nursing home, respectively, 9 still receiving ITO2 via MT as chronic oxygen therapy. CONCLUSION Our results suggest that MT insertion for ITO2 may be a therapeutic option in selected patients with respiratory failure from CLD.
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Affiliation(s)
- P Andrivet
- Medical Intensive Care Unit, CMC Bligny, Briis/Forges, France
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Barnett CC, Moore FA, Moore EE, Partrick DA, Goodman J, Burch JM, Haenel JB. Tracheal gas insufflation is a useful adjunct in permissive hypercapnic management of acute respiratory distress syndrome. Am J Surg 1996; 172:518-21; discussion 521-2. [PMID: 8942556 DOI: 10.1016/s0002-9610(96)00250-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Despite numerous advances in critical care, the mortality of postinjury acute respiratory distress syndrome (ARDS) remains high. Recently, permissive hypercapnia (PHC) has been shown to be a viable alternative to traditional ventilator management in patients with ARDS. However, lowering tidal volume, as employed in PHC, below 5 cc/kg impinges upon anatomic dead space and precipitates a significant rise in PaCO2 The purpose of this study was to determine if continuous tracheal gas insufflation (cTGI) is a useful adjunct to PHC by lowering PaCO2, thus allowing adequate reduction in minute ventilation to achieve alveolar protection. METHODS Over a 5-year period, 68 trauma patients with ARDS were placed on permissive hypercapnia. Nine of these patients additionally received cTGI at 7 L/min. Arterial blood gas determinations and ventilatory parameters were examined immediately prior to the implementation of cTGI and after 6h. RESULTS The cTGI produced significant improvement in pH (7.25 +/- 0.03 to 7.33 +/- 0.03), PaCO2 (72 +/- 5 to 59 +/- 5 torr), tidal volume (7.9 +/- 0.6 to 7.2 +/- 0.6 cc/kg), and minute ventilation (13 +/- 1 to 11 +/- 1 L/min; P < 0.05). CONCLUSIONS Continuous TGI is a useful adjunct to permissive hypercapnia, allowing maintenance of an acceptable pH and PaCO2 while allowing further reduction in tidal volume and minute ventilation.
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Affiliation(s)
- C C Barnett
- Department of Surgery, Denver General Hospital, Colorado, USA
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25
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Hotchkiss JR, Crooke PS, Marini JJ. Theoretical interactions between ventilator settings and proximal deadspace ventilation during tracheal gas insufflation. Intensive Care Med 1996; 22:1112-9. [PMID: 8923080 DOI: 10.1007/bf01699238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To investigate the theoretical interactions between ventilator settings, tracheal gas insufflation (TGI), and alveolar ventilation. DESIGN We derived differential equations governing compartmental volume changes in a one-compartment model of TGI-assisted ventilation and equations governing gas dilution in the airway proximal to the TGI catheter and the additional CO2 clearing ventilation arising from this dilution. This additional ventilation was called proximal ventilation. Validation was conducted in a mechanical lung analog. Model predictions for proximal ventilation were then generated over wide ranges of frequency, duty cycle, and tidal volume. RESULTS Significant interactions were identified between ventilator settings and proximal ventilation. The persistence of end-expiratory flow from the lung decreased proximal dilution by fresh gas and thereby reduced TGI-aided proximal ventilation. Changes in end-expiratory lung flow resulting from alterations in ventilator settings were correlated inversely with proximal ventilation. CONCLUSIONS During TGI with constant catheter flow, ventilator settings that promote end-expiratory flow of gas from the lung diminish proximal ventilation. When frequency increases, the decrease in dilution efficiency of the individual breath is partially offset by the increase in cycle number, an effect which is magnified by any concomitant decrease in inspired tidal volume. Prolongation of the duty cycle tends to decrease proximal ventilation. Increases in expiratory resistance, including those arising from the external ventilator circuit or the endotracheal tube, also impair proximal ventilation.
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Affiliation(s)
- J R Hotchkiss
- University of Minnesota, St. Paul Ramsey Medical Center, St. Paul 55101, USA
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Abstract
With few modifications, a high tidal volume, normoxic, normocapnic ventilation paradigm developed as the standard approach to supporting most critically ill patients. Large tidal volumes, high end-tidal (plateau) alveolar pressures, and low levels of positive end-expiratory pressure are still common in many ICUs during ventilation of acute respiratory distress syndrome (ARDS). A body of scientific literature now suggests that this traditional approach may retard healing of the injured lung. A relatively small but growing number of practitioners are shifting their first priority from optimizing oxygen exchange, oxygen delivery, or respiratory system compliance to ensuring adequate lung protection. This article reviews the basis for concern about traditional ventilatory support in ARDS and develops an approach based on current evidence and newer options for management.
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Affiliation(s)
- J J Marini
- Department of Pulmonary and Critical Care Medicine, St. Paul-Ramsey Medical Center, Minnesota, USA
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Hoyt JD, Marini JJ, Nahum A. Effect of tracheal gas insufflation on demand valve triggering and total work during continuous positive airway pressure ventilation. Chest 1996; 110:775-83. [PMID: 8797426 DOI: 10.1378/chest.110.3.775] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Tracheal gas insufflation (TGI) improves CO2 clearance and may reduce work of breathing by lowering the required minute ventilation (VE). However, TGI might also impair the ability to trigger the ventilator, because to lower external circuit pressures, inspiratory effort must outstrip catheter flow rate (Vc) and overcome the dynamic hyperinflation caused by TGI. We studied these effects using a two-chamber lung model of the respiratory muscles (RM) and lungs (L). The RM-chamber was ventilated using a sinusoidal flow pattern with a tidal volume (VT) of 0.5 L at various peak inspiratory flow rates (Vpk) to simulate differences in effort intensity. The L-chamber was connected to a 60-L/min continuous flow circuit with a 10 cm H2O positive end-expiratory pressure valve and to 3 different ventilatory demand valve circuits, each set at continuous positive airway pressure (CPAP) of 10 cm H2O. We used continuous TGI at 0, 2.5, 5, 10, and 15 L/min. The work of triggering (W-trig) increased with increasing Vc and decreased with increasing Vpk. The L-ventilator failed to trigger when Vc was 15 L/min and Vpk was 20 L/min. At a fixed VE, the effect of TGI on total mechanical inspiratory work (W-tot) was relatively small and varied among the different CPAP systems used. We conclude that weak patients may fail to open the demand valve of the CPAP system during TGI at high catheter flow rates. The net effect of TGI on the effort made by ventilated patients would depend not only on the interactions between TGI and the ventilator, but also on the efficiency of TGI in decreasing dead-space and lowering the VE requirement.
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Affiliation(s)
- J D Hoyt
- University of Minnesota, Department of Pulmonary and Critical Care Medicine, St. Paul-Ramsey Medical Center, St. Paul, USA
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Abstract
The available evidence indicates that pulmonary rehabilitation benefits patients with symptomatic COPD. The effect of pulmonary rehabilitation programs on health care use is promising but requires further investigation. In contrast, aerobic lower extremity training is of benefit in several areas of importance to patients with COPD. These areas include exercise endurance, perception of dyspnea, quality of life, and self-efficacy. The exact role of upper extremity exercise training programs requires further studies but should be used in patients who develop symptoms with arm activities. Psychological support improves the awareness of the patient and increases his or her understanding of the disease, but when used alone it is of limited value. Pulmonary rehabilitation when coupled with smoking cessation, optimization of blood gases, and medications offers the best treatment option for patients with symptomatic airflow obstruction.
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Affiliation(s)
- B R Celli
- Department of Pulmonary/Critical Care, St. Elizabeth's Medical Center Boston, Massachusetts, USA
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Eckmann DM, Gavriely N. Chest vibration redistributes intra-airway CO2 during tracheal insufflation in ventilatory failure. Crit Care Med 1996; 24:451-7. [PMID: 8625634 DOI: 10.1097/00003246-199603000-00015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To determine if high-frequency external chest wall vibration added to low flow intratracheal fresh gas insufflation alters the intra-airway CO2 distribution and the resistance to CO2 transport from the lungs. DESIGN Prospective study. SETTING Experimental laboratory. SUBJECTS Six adult anesthesized and paralyzed mongrel dogs (mean weight 24.3+/- 4.4 kg). INTERVENTIONS Dogs were ventilated by three methods: a) intermittent positive pressure ventilation; b) intermittent positive pressure ventilation with tracheal insufflation of fresh gas (FIO2 of 0.4) flowing at 0.15 L/kg/min through a catheter positioned at the carina; and c) intermittent positive pressure ventilation with tracheal insufflation and with external high-frequency chest wall vibration of the dependent hemithorax. MEASUREMENTS AND MAIN RESULTS We measured arterial blood gas values as an index of global gas exchange, and intrapulmonary airway CO2 concentrations as an index of local gas exchange. Intra-airway CO2 concentrations along the axis of the airways were measured via a sampling catheter. Airway axial concentration profiles were constructed and resistances to gas transport were calculated from the measured data. Vibration increased intraluminal CO2 concentrations from 1.1% to 2.5% mouthward of the insufflation catheter tip. Peak resistance to CO2 transport decreased by 65% during vibration relative to the insufflation-only value. Vibration displaced peak transport resistance from second- to fourth-generation airways. CONCLUSIONS Global gas exchange improves during ventilation by chest wall vibration with low flow insufflation. Local gas exchange in the central airways is also improved due to increased intraluminal mixing and CO2 elimination. This ventilation technique may confer therapeutic advantages over conventional mechanical ventilation in the treatment of ventilatory failure.
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Affiliation(s)
- D M Eckmann
- Department of Anesthesia, Northwestern University Medical School, Evanston, Illinois, USA
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Nakos G, Lachana A, Prekates A, Pneumatikos J, Guillaume M, Pappas K, Tsagaris H. Respiratory effects of tracheal gas insufflation in spontaneously breathing COPD patients. Intensive Care Med 1995; 21:904-12. [PMID: 8636522 DOI: 10.1007/bf01712331] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To evaluate the effect of tracheal gas insufflation (TGI) in spontaneously breathing, intubated patients with chronic obstructive pulmonary disease (COPD) undergoing weaning from the mechanical ventilation. DESIGN A prospective study in humans. SETTING Polyvalent intensive care unit (14-bed ICU) in a 700-bed general university hospital. PATIENTS Twelve patients with chronic obstructive pulmonary disease (COPD) who required intubation and mechanical ventilation were studied. All patients met standard criteria for weaning from mechanical ventilation. Seven patients (group 1) had been transorally intubated during episodes of acute respiratory failure. Five patients, all men (group 2), had previously undergone tracheostomy and had a transtracheal tube in place. INTERVENTIONS Intratracheal, humidified, O2-mixture insufflation (TGI) was given via a catheter placed in distal or proximal position. Gas delivered through the intratracheal catheter was blended to match the fractional of inspired gas through the endotracheal tube. Continuous flows of 3 and 6 l/min in randomized order were used in each catheter position. Prior to data collection at each stage, an equilibration period of at least 30 min was observed, and thereafter blood gases were analyzed every 5 min. A new steady state was assumed to have been established when values of both PaCO2 and V CO2 changed by less than 5% between adjacent measurements. The last values of blood gases were taken as representative. The new steady state was confirmed within 35-50 min. Baseline measurements with zero Vcath were made at the beginning and end of the experiment. RESULTS This study shows that VT, MV, PaCO2, and VD/VT are reduced in a flow-dependent manner when gas is delivered through an oral-tracheal tube (group 1). The distal catheter position was more effective than the proximal one. In contrast, when gas was delivered through tracheostomy (group 2), TGI was ineffective in the proximal position and less effective than in group 1 in distal position. CONCLUSION Under the experimental conditions, tracheal gas insufflation decreased dead space, increased alveolar ventilation and possibly reduced work of breathing. From the preliminary data reported here, we believe that TGI may help patients experiencing difficulty during weaning.
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Affiliation(s)
- G Nakos
- Intensive Care Medicine Department, University Hospital of Ioannina, Greece
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Belghith M, Fierobe L, Brunet F, Monchi M, Mira JP. Is tracheal gas insufflation an alternative to extrapulmonary gas exchangers in severe ARDS? Chest 1995; 107:1416-9. [PMID: 7750341 DOI: 10.1378/chest.107.5.1416] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Tracheal gas insufflation (TGI) of pure oxygen combined with mechanical ventilation decreases dead space and increases CO2 clearance. In the present study, TGI was used in six patients with ARDS who met extracorporeal membrane oxygenation criteria and who were severely hypoxemic and hypercapnic despite optimal pressure-controlled ventilation. This open clinical study aimed to investigate the effects of 4 L/min continuous flow of oxygen given via an intratracheal catheter. PaCO2 decreased from 108 +/- 32 to 84 +/- 26 mm Hg (p < 0.05), and no significant change in PaO2 (68 +/- 18 vs 96 +/- 43, p = 0.06). There was no change in airway pressures and hemodynamic variables. A slight increase in end-expiratory and end-inspiratory volumes with TGI possibly occurred, as seen on tracings from respiratory inductive plethysmography (Respitrace). We conclude that TGI improves tolerance of limited pressure ventilation by removing CO2, but it may induce changes in lung volumes that are not detected by ventilator measurements.
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Affiliation(s)
- M Belghith
- Intensive Care Unit, Cochin-University Hospital, Paris, France
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Nakos G, Zakinthinos S, Kotanidou A, Tsagaris H, Roussos C. Tracheal gas insufflation reduces the tidal volume while PaCO2 is maintained constant. Intensive Care Med 1994; 20:407-13. [PMID: 7798444 DOI: 10.1007/bf01710650] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE The aims of the present study were two-fold: first, to confirm the effect of tracheal gas insufflation (TGI) throughout the respiratory cycle on alveolar ventilation at various catheter flows and constant total inspired VT as an adjunct to conventional volume cycled mechanical ventilation in patients with acute lung injury; second, to test the efficacy of TGI in the reduction of toal VT, peak and mean airway pressure while maintaining PaCO2 in its baseline value. The hemodynamic effect and the consequences on oxygenation as result of the reduction of VT, were also estimated. DESIGN Prospective study of patients with acute lung injury requiring mechanical ventilation. SETTING 12 bedded, adult polyvalent intensive care unit in a teaching hospital. PATIENTS 7 paralyzed and sedated patients with acute respiratory failure were studied. All patients were clinically and hemodynamically stable without fluctuation of the body temperature. All patients were orally intubated with cuffed endotracheal tubes, and mechanically ventilated with a standard circuit of known compliance. INTERVENTIONS Continuous flows (4 and 6 l/min) were delivered through a catheter positioned 1 cm above carina while tidal volume or PaCO2 were maintained constant at their baseline value. RESULTS In this study a modest level of TGI significantly enhanced CO2 elimination in patients with acute respiratory failure. Improved ventilatory efficiency resulted from the functional reduction of dead space during TGI allowing the same PaCO2 to be maintained at the same frequency with lower tidal volume and lower airway pressure requirement. Tidal volume, peak and mean airway pressure decreased linearly with catheter flow, without significant changes in oxygenation, while PaCO2 remained stable. CONCLUSION The results of this study suggest that TGI may be an useful adjunct mode of mechanical ventilation that limits alveolar pressure and minute ventilation requirements.
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Affiliation(s)
- G Nakos
- Evangelismos Hospital, Athens, Greece
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Affiliation(s)
- J J Marini
- Department of Pulmonary and Critical Care Medicine, University of Minnesota, St. Paul
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Affiliation(s)
- A F Barker
- Oregon Health Sciences University, Portland 97201
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Ravenscraft SA, Burke WC, Nahum A, Adams AB, Nakos G, Marcy TW, Marini JJ. Tracheal gas insufflation augments CO2 clearance during mechanical ventilation. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1993; 148:345-51. [PMID: 8342897 DOI: 10.1164/ajrccm/148.2.345] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A technique that improves the efficiency of alveolar ventilation should decrease the pressure required and reduce the potential for lung injury during mechanical ventilation. Alveolar ventilation may be improved by replacing a portion of the anatomic dead space with fresh gas via an intratracheal catheter. We studied the effect of intratracheal gas insufflation as an adjunct to volume cycled ventilation in eight sedated, paralyzed patients with a variety of lung disorders. Continuous flows of 2, 4, and 6 L/min were delivered through a catheter positioned 1 or 10 cm above the carina. Carbon dioxide production, inspiratory minute ventilation, and peak and mean airway pressures did not change over the range of flows tested. PaCO2 and dead space volume/tidal volume decreased significantly as joint functions of catheter flow and position (p < 0.001). The highest catheter flow (6 L/min) and most distal catheter position (1 cm above the carina) were the most effective combination tested, averaging a 15% reduction in PaCO2 (range 9 to 23%). Certain characteristics of the expiratory capnogram were helpful in predicting the observed reduction in PaCO2. Tracheal gas insufflation may eventually prove a useful adjunct to a pressure-targeted strategy of ventilatory management (in either volume-cycled or pressure controlled modes), particularly when the total dead space is heavily influenced by its anatomic component.
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Affiliation(s)
- S A Ravenscraft
- Division of Pulmonary and Critical Care Medicine, University of Minnesota, Minneapolis/St. Paul
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Benditt J, Pollock M, Roa J, Celli B. Transtracheal delivery of gas decreases the oxygen cost of breathing. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1993; 147:1207-10. [PMID: 8484632 DOI: 10.1164/ajrccm/147.5.1207] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Transtracheally administered gases decrease inspired minute ventilation in both dogs and humans. To test if this is associated with a decrease in the oxygen cost of breathing and to evaluate subsequent changes in the breathing pattern, we studied five patients with chronic respiratory diseases while they spontaneously breathed air and different flows of tracheally administered gases. In a blinded crossover design, the gas consisted of either oxygen or air at 2, 4, and 6 L/min. Oxygen cost of breathing was estimated by the calculation of pleural pressure-time index (PPTI). The pattern of breathing was evaluated utilizing the tension time index for the diaphragm (TTdi). There were significant decreases in PPTI when the patients received 2, 4, and 6 L/min of transtracheal oxygen or air. TTdi also decreased as gas flow increased. This drop was significant at 6 L/min flow for both gases. We conclude that transtracheally administered gas reduces the oxygen cost of breathing. It also changes the respiratory pattern of the diaphragm to a less demanding pattern. This may offer an alternative form of treatment to rest overworked respiratory muscles.
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Affiliation(s)
- J Benditt
- Pulmonary Section, Department of Veterans Affairs Medical Center, Boston, MA 02130
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Gavriely N, Eckmann D, Grotberg JB. Gas exchange by intratracheal insufflation in a ventilatory failure dog model. J Clin Invest 1992; 90:2376-83. [PMID: 1469093 PMCID: PMC443393 DOI: 10.1172/jci116128] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Respiratory insufficiency patients who need only partial ventilatory support are, nevertheless, intubated and connected to a respirator. In search of a partial respiratory assistance method we evaluated the gas exchange, mechanisms, and hemodynamic effects of intratracheal insufflation (ITI) via a narrow (0.2-cm) catheter. The effects of flow rate (0.05-0.2 liter/min per kg), catheter tip position (carina, bronchus, and trachea), and superimposed chest vibration at 22 Hz were studied in seven anesthetized and partially paralyzed dogs. ITI in the carina induced CO2 removal (VCO2) of 48 +/- 16 ml/min in the periods between breaths, which was 39% of the control VCO2. CO2 removal rates between breaths with ITI in a bronchus and in the trachea were 63 and 28% of control, respectively (P < 0.05). ITI at 0.15-0.2 liter/min per kg augmented total VCO2 by > 50% over control (P < 0.05) and decreased PaCO2 by 10% (P < 0.05) despite a 28% fall in VE and 32% lower work of breathing (P < 0.05). Adding vibration to ITI at 0.15 liter/min per kg induced VCO2 of 162 +/- 34 ml/min, which was significantly greater than control, while PaCO2 fell from 69 +/- 24 to 47 +/- 6 mmHg (P < 0.05), despite complete cessation of spontaneous breathing. ITI with or without vibration did not cause any hemodynamic changes, except for a fall in the shunt fraction from 14.6 +/- 9.9% to 5.8 +/- 2.8% with vibration. Thus, ITI at low flow rates can support respiration with no hemodynamic side effects. Adding chest vibration further enhances gas exchange and can provide total ventilation.
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Affiliation(s)
- N Gavriely
- Department of Anesthesia, Northwestern University Medical School, Chicago, Illinois 60611
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Hoffman LA, Wesmiller SW, Sciurba FC, Johnson JT, Ferson PF, Zullo TG, Dauber JH. Nasal cannula and transtracheal oxygen delivery. A comparison of patient response after 6 months of each technique. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1992; 145:827-31. [PMID: 1554209 DOI: 10.1164/ajrccm/145.4_pt_1.827] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of this study was to compare the efficacy of transtracheal (TT) oxygen delivery to that of nasal cannula delivery in subjects with chronic obstructive pulmonary disease (COPD). Twenty subjects (14 men, 6 women) were followed for 6 months during nasal cannula delivery. A TT catheter was then inserted, and measurements were repeated during TT use. With TT delivery, subjects required 45% less oxygen at rest and 39% less during exercise (p less than 0.0001). Oxygen use, measured by pounds of oxygen delivered to the home, also decreased, but the magnitude of change was less than anticipated (mean, 14%; range, +4% to -32%). Hospital days decreased from 12 +/- 10 during nasal cannula use to 4 +/- 6 during TT use (p less than 0.002). Exercise tolerance, as measured by a 12-min walk distance, was greater during TT use (p less than 0.0001). No change was seen in spirometry or acid-base balance. Also, no change was seen in Profile of Mood States, Sickness Impact Profile or Katz Adjustment Scale scores. Some problems were encountered relating to use of the catheter (displacement, mucus balls), but they were minor, and most were confined to the initial 2 months of TT use when the tract was immature. Our experience suggests that, in addition to decreasing oxygen flow rate, use of TT delivery may confer benefits that result in improved exercise tolerance and decreased hospitalization in patients with COPD.
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Affiliation(s)
- L A Hoffman
- Pulmonary Nursing Program, School of Nursing, University of Pittsburgh, Pennsylvania 15261
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