The "2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" increased the focus on methods to ensure that high-quality cardiopulmonary resus...

Cardiopulmonary resuscitation quality: Improving cardiac resuscitation outcomes both inside and outside the hospital: A consensus statement from the American heart association

Context:This translational research initiative focused on the physiology of cardiopulmonary resuscitation (CPR) initiated by a clinical observation of consistent hyperventilation by professional rescuers in out-of-hospital cardiac arrest. This observation generated scientific hypotheses that could o

Death by hyperventilation: a common and life-threatening problem during cardiopulmonary resuscitation.

In 10 patients with severe, acute respiratory failure we studied the effects of positive end-expiratory pressure when intermittent positive pressure ventilation (IPPV) with inspired oxygen (F(IO2)) up to 0.5 failed to maintain arterial oxygen tension (P(aO2)) above 70 torr.Positive end-expiratory pressures (PEEP) of 0, 5, 10, and 15 cm H(2)O were applied for 30-min periods each and in random order. Blood gas exchange, lung volumes, compliance, and hemodynamics were studied at each level of PEEP. P(aO2) (F(IO2) = 1.0) rose linearly with elevation of PEEP, the mean increase being from 152 to 347 torr, or 13 torr/cm H(2)O PEEP. Mean functional residual capacity (FRC) was 1.48+/-0.78 liters at zero PEEP (i.e., IPPV) and the increase was essentially linear, reaching 2.37 liters at 15 cm H(2)O PEEP. P(aO2) and FRC showed a close correlation. Total and lung static compliance were greater during ventilation with high than with low levels of PEEP. The increase in P(aO2) correlated with the specific lung compliance. Dynamic lung compliance decreased progressively with rising levels of PEEP except for an increase with 5 and 10 cm H(2)O PEEP in patients with initial values of 0.06 liter/cm H(2)O or higher. Cardiac index fell in some patients and rose in others and there was no correlation of mean cardiac index, systemic blood pressure, or peripheral vascular resistance with level of PEEP. The most probable explanation for the effect of PEEP on P(aO2) and compliance is recruitment of gas exchange airspaces and prevention of terminal airway closure.

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Ventilation with end-expiratory pressure in acute lung disease

Effect of Mechanical Ventilation and Airway Pressures on Circulation and Blood Gas Exchange The ventilatory pattern is defined by: the inspiratory and expiratory flow rates and pressures, including...

Acute respiratory failure in the adult

We investigated the efficacy of intratracheal perfluorocarbon (PFC) administration combined with mechanical ventilation to support gas exchange in adult animals with acute respiratory failure. These were compared with a similar group of animals treated with continuous positive-pressure ventilation (CPPV) with respect to respiratory parameters and postmortem lung histology. After lung lavage with saline, 18 adult rabbits were divided into three groups (n = 6 per group). All groups received conventional CPPV. Additionally, one group received intratracheal PFC administration at a volume of 18 ml/kg (corresponding to functional residual capacity) (PFC group); another received 18 ml/kg of saline administration (saline group), and the last had no further treatment (CPPV group). All groups were ventilated for 3 h using 100% oxygen, with the same ventilator settings of tidal volume of 12 ml/kg, respiratory frequency of 30/min, and positive end-expiratory pressure of 6 cm H2O. In the PFC group, PaO2 increased from...

Comparison of Ventilatory Support with Intratracheal Perfluorocarbon Administration and Conventional Mechanical Ventilation in Animals with Acute Respiratory Failure

SUMMARY The effects of altering end-expiratory inflation pressure were studied in mechanically ventilated dogs in the normo-, hypo- and hypervolaemic state. The mean fall in cardiac output resulting from an increase in end-expiratory pressure was smaller in the hypervolaemic group than in the other two groups. A positive end-expiratory pressure increased the mean deadspace/tidal volume ratio in all groups. A negative end-expiratory pressure increased venous admixture, particularly in the over-transfused animals, but the increase was not significant in the hypovolaemic group. A negative end-expiratory pressure did not affect deadspace/tidal volume ratio.

The effects of variations in end-expiratory inflation pressure on cardiorespiratory function in normo-, hypo and hypervolaemic dogs

The effects of variations in end-expiratory inflation pressure on cardiorespiratory function in normo-, hypo- and hypervolaemic dogs

SUMMARY The effects of changes in applied positive pressure waveform during inspiration were studied in anaesthetized dogs mechanically ventilated with air in the normo-, hypo- and hypervolaemic states. Four waveforms were used (sine, square, late peak and early peak flow patterns), these being delivered from a specially constructed ventilator which behaved as a volume preset machine in the inspiratory phase. Controlled ventilation was performed at a constant frequency of 20 respirations per minute at a fixed inspiratory: expiratory ratio of 1:2. None of the waveforms used was found to produce significant changes in cardiorespiratory function within any of the three states of blood volume.

The effects of variations of inspiratory flow waveform on cardiorespiratory function during controlled ventilation in normo-, hypo- and hypervolaemic dogs

A. Economides

Papers

The effects of variations in end-expiratory inflation pressure on cardiorespiratory function in normo-, hypo and hypervolaemic dogs

The effects of variations in end-expiratory inflation pressure on cardiorespiratory function in normo-, hypo- and hypervolaemic dogs

The effects of variations of inspiratory flow waveform on cardiorespiratory function during controlled ventilation in normo-, hypo- and hypervolaemic dogs