Biophysics of cardiopulmonary resuscitation with periodic z-axis acceleration or abdominal compression at aortic resonant frequencies

Nasopharyngeal oxygen with intermittent nose-close and abdomen-compression: a novel resuscitation technique in a piglet model

OBJECTIVE

To evaluate the efficacy of a simple and novel cardiopulmonary resuscitation (CPR) technique, nasopharyngeal oxygen with intermittent nose-close and abdomen-compression (NPO(2) -NC-AC) in an animal model.

DESIGN

Prospective piglet study.

SETTING

In an animal physiology laboratory of a medical university. PIGLETS: Six healthy piglets <14 days old.

INTERVENTIONS

Spontaneous breathing of the anesthetized piglets (n = 6) was medically ceased until severe bradycardia (<20 beat/min). NPO(2) -NC-AC CPR trial was then initiated by delivering NPO(2) at 1.0-1.5 L/kg/min and intermittently performing the NC-AC maneuver: (1) NC for inspiration, occluded nostrils for 1 sec; and (2) AC for expiration, released nostrils, and compressed the abdomen for 1 sec. NC-AC was repeated at a rate of 30/min for 5 min. This CPR trial was repeated three times in each piglet. Cardiopulmonary variables were monitored, recorded, and compared.

MEASUREMENTS AND MAIN RESULTS

A total of 18 CPR trials were performed. All of these acute life-threatening asphyxia events rapidly improved within 1 min of CPR. Cardiopulmonary variables recovered to the baseline levels and oxygenation continually increased. The intratracheal pressure (P(tr) ) values of positive end expiratory pressure and peak inspiratory pressure values were 4.3 ± 0.8 cmH(2) O and 26.2 ± 4.1 cmH(2) O, respectively. Chest wall movement was observed when the P(tr) reached 17.5 ± 3.1 cmH(2) O. All six piglets fully recovered after 63.8 ± 7.2 min of experiment without additional support.

CONCLUSIONS

NPO(2) -NC-AC is a simple and effective CPR technique for severe acute cardiopulmonary asphyxia in piglets. It may be clinically applicable for supportive or rescue use.

Abdominal only CPR during cardiac arrest for a patient with an LVAD during resternotomy: a case report

We present a case in which a patient with a previous sternotomy and left ventricular assist device (LVAD) implantation developed cardiac arrest during resternotomy for LVAD exchange. The surgeon refused chest compressions for fear of potential damage to the inflow cannula directly beneath the sternum. The perioperative team had no alternatives to external cardiac massage other than rapid deployment of extra-corporeal membrane oxygenation for mechanical support, so the anesthesiologist advised the nursing personnel to perform abdominal only cardiopulmonary resuscitation while the surgeon performed a femoral bypass to cannulate the groin for extra-corporeal membrane oxygenation support.

Endothelium and cardiopulmonary resuscitation

The endothelium is a viable target for injury, repair and cellular modulation. Because of its vast extension and active metabolic status of producing mediators for vasomotor tone, coagulation, and inflammation, it is a key target for therapy during ischemia/reperfusion injury. Cardiopulmonary resuscitation is a model of whole-body ischemia/reperfusion injury. It has become apparent that the endothelium participates in a host of responses elicited by ischemia/reperfusion. This review examines the role of the endothelium during and after ischemia/reperfusion and the participation by its mediators and evidence for endothelial involvement during and after cardiopulmonary resuscitation. The strategic location of the endothelium makes it an excellent signal transduction mechanism for a host of disease processes. In addition to biochemical stimuli, mechanical stimulation of the endothelium elicits production of several mediators, including endothelium-derived nitric oxide, prostaglandins, and antithrombotics and anticoagulants. Whole-body, periodic acceleration is a novel method of stimulating the endothelium via pulsatile shear stress. Periodic acceleration has been shown to be an effective experimental method of cardiopulmonary resuscitation, with evidence of postresuscitation cardioprotective effects. This review indicates that understanding endothelial modulation during and after ischemia/reperfusion will significantly improve therapeutic choices.