The mechanism of blood flow in cardiopulmonary resuscitation—introducing the lung pump

Shaw, David P.; Rütherford, J. S.; Williams, Michael J.A.

doi:10.1016/s0300-9572(97)00038-5

Cited by 9 publications

(10 citation statements)

References 34 publications

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“…Finally, the fourth class includes devices, such as human inventions, which may operate as an outside agency on the body and directly or indirectly promote arterial flow and/or venous return. An example of this would be cardiopulmonary resuscitation, such as the lung pump (Shaw et al 1997). The Z-flow concept permits quantitative analysis of systems with and without valves.…”

Section: Impedance-defined Flow (Z-flow)mentioning

confidence: 99%

The Donders Model of the Circulation in Normo- and Pathophysiology

et al. 2006

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The solution of some recent as well as of long standing problems, unanswerable due to experimental inaccessibility or moral objections are addressed. In this report, a model of the closed human cardiovascular loop is developed. This model, using one set of 88 equations, allows variations from normal resting conditions to exercise, as well as to the ultimate condition of a circulation following cardiac arrest. The principal purpose of the model is to evaluate the continuum of physiological conditions to cardiopulmonary resuscitation (CPR) effects within the circulation.Within the model, Harvey's view of the circulation has been broadened to include impedance-defined flow as a unifying concept, and as a mechanism in CPR. The model shows that depth of respiration, sympathetic stimulation of cardiac contractile properties and baroreceptor activity can exert powerful influences on the increase in cardiac output, while heart and respiratory rate increases tend to exert an inhibiting influence, with the pressure and flow curves compatible with accepted references. Impedance-defined flow encompasses both positive and negative effects.The model also demonstrates the limitations to cardiopulmonary resuscitation caused by external force applied to intrathoracic structures, with effective cardiac output being limited by collapse and sloshing. Stroke volumes from 6 to 51 ml are demonstrated. It shows that the clinical inclination to apply high pressures to intrathoracic structures may not be rewarded with improved net flow.

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Section: Impedance-defined Flow (Z-flow)mentioning

confidence: 99%

The Donders Model of the Circulation in Normo- and Pathophysiology

et al. 2006

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“…However, it has been widely accepted that simultaneous chest compression and ventilation at high airway pressure improves the systemic arterial pressure in humans [17, 18] and experimental models [19]. An open airway limits the effect of the thoracic pump [8] as the pressure measured in the airway becomes equal to the atmospheric pressure. In our experimental setting, the ventilation system was used with a closed circuit.…”

Section: Discussionmentioning

confidence: 99%

“…The competing concepts as to whether the heart is a pump or a conduit have caused much controversy. As a result, the mechanism of chest compression is often explained by the lung pump theory, in which the heart works as a part of the larger pumping system with the lungs [4, 8]. Our work was not conducted to separately investigate this point.…”

Section: Discussionmentioning

confidence: 99%

“…These competing concepts of whether the heart is a pump or a conduit have caused much controversy. The mechanism of chest compression is often explained by the lung pump theory, in which the heart works as a part of the larger pumping system with the lungs [4, 8]. Rudikoff [7] measured pressures in “the heart pump” in dogs, including the left ventricle, aorta, right atrium, and pulmonary artery, which were identical and equal to the intrathoracic pressure estimated by an esophageal balloon catheter.…”

Section: Introductionmentioning

confidence: 99%

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Combination of cardiac and thoracic pump theories in rodent cardiopulmonary resuscitation: a new method of three-side chest compression

Okuma

Shinozaki

Yagi

et al. 2019

ICMx

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BackgroundHigh-quality cardiopulmonary resuscitation (HQ-CPR) is of paramount importance to improve neurological outcomes of cardiac arrest (CA). The purpose of this study was to evaluate chest compression methods by combining two theories: cardiac and thoracic pumps.MethodsMale Sprague-Dawley rats were used. Three types of chest compression methods were studied. The 1-side method was performed vertically with 2 fingers over the sternum. The 2-side method was performed horizontally with 2 fingers, bilaterally squeezing the chest wall. The 3-side method combined the 1-side and the 2-side methods. Rats underwent 10 min of asphyxial CA. We examined ROSC rates, the left ventricular functions, several arterial pressures, intrathoracic pressure, and brain tissue oxygen.ResultsThe 3-side group achieved 100% return of spontaneous circulation (ROSC) from asphyxial CA, while the 1-side group and 2-side group achieved 80% and 60% ROSC, respectively. Three-side chest compression significantly shortened the time for ROSC among the groups (1-side, 105 ± 36.0; 2-side, 141 ± 21.7; 3-side, 57.8 ± 12.3 s, respectively, P < 0.05). Three-side significantly increased the intrathoracic pressure (esophagus, 7.6 ± 1.9, 7.3 ± 2.8, vs. 12.7 ± 2.2; mmHg, P < 0.01), the cardiac stroke volume (the ratio of the baseline 1.2 ± 0.6, 1.3 ± 0.1, vs. 2.1 ± 0.6, P < 0.05), and the common carotid arterial pressure (subtracted by femoral arterial pressure 4.0 ± 2.5, 0.3 ± 1.6, vs. 8.4 ± 2.6; mmHg, P < 0.01). Three-side significantly increased the brain tissue oxygen (the ratio of baseline 1.4±0.1, 1.3±0.2, vs. 1.6 ± 0.04, P < 0.05).ConclusionsThese results suggest that increased intrathoracic pressure by 3-side CPR improves the cardiac output, which may in turn help brain oxygenation during CPR.

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“…[19,26]. Auch ein durch zyklische externe Thoraxkompressionen erzeugter positiver Atemwegsdruck kann so einen antegraden Blutfluss von den pulmonalen Gefäßen durch das linke Herz in die Aorta unterstützen [43]. Kerns Modell der Thoraxkompression mit abgeklemmtem Tubus [32] ist mit der Situation eines nichtintubierten Patienten während einer Ersthelferreanimation in keiner Weise vergleichbar.…”

Section: Introductionunclassified

Kardiopulmonale Reanimation ?oben ohne?

2004

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A decade after the onset of a discussion whether ventilation could be omitted from bystander basic life support (BLS) algorithms, the state of the evidence is reevaluated. Initial animal studies and a prospective randomized patient trial had suggested that omission of ventilation during the first minutes of lay cardiopulmonary resuscitation (CPR) did not impair patient outcomes. More recent studies demonstrate, however, that this may hold true only in very specific scenarios, and that the chest compression-only technique was never superior to standard BLS. Instead of calling basics of BLS training and practice into question, more and better training of lay persons and professionals appears mandatory, and targeted use of dispatcher-guided telephone CPR should be evaluated and, if it improves outcome, it should be encouraged. Future studies should focus much less on the omission but on the optimization of ventilation under the specific conditions of CPR.

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The mechanism of blood flow in cardiopulmonary resuscitation—introducing the lung pump

Cited by 9 publications

References 34 publications

The Donders Model of the Circulation in Normo- and Pathophysiology

The Donders Model of the Circulation in Normo- and Pathophysiology

Combination of cardiac and thoracic pump theories in rodent cardiopulmonary resuscitation: a new method of three-side chest compression

Kardiopulmonale Reanimation ?oben ohne?

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