Return of spontaneous Circulation Is Not Affected by Different Chest Compression Rates Superimposed with Sustained Inflations during Cardiopulmonary Resuscitation in Newborn Piglets

Abstract

ObjectiveRecently, sustained inflations (SI) during chest compression (CC) have been suggested as an alternative to the current approach during neonatal resuscitation. However, the optimal rate of CC during SI has not yet been established. Our aim was to determine whether different CC rates during SI reduce time to return of spontaneous circulation (ROSC) and improve hemodynamic recovery in newborn piglets with asphyxia-induced bradycardia.Intervention and measurementsTerm newborn piglets were anesthetized, intubated, instrumented and exposed to 45-min normocapnic hypoxia followed by asphyxia. Resuscitation was initiated when heart rate decreased to 25% of baseline. Piglets were randomized into three groups: CC superimposed by SI at a rate of 90 CC per minute (SI+CC 90, n = 8), CC superimposed by SI at a rate of 120 CC per minute (SI+CC 120, n = 8), or a sham group (n = 6). Cardiac function, carotid blood flow, cerebral oxygenation and respiratory parameters were continuously recorded throughout the experiment.Main resultsBoth treatment groups had similar time of ROSC, survival rates, hemodynamic and respiratory parameters during cardiopulmonary resuscitation. The hemodynamic recovery in the subsequent 4h was similar in both groups and was only slightly lower than sham-operated piglets at the end of experiment.ConclusionNewborn piglets resuscitated by SI+CC 120 did not show a significant advantage in ROSC, survival, and hemodynamic recovery as compared to those piglets resuscitated by SI+CC 90.

Chest compression during sustained inflation versus 3:1 chest compression:ventilation ratio during neonatal cardiopulmonary resuscitation: a randomised feasibility trial

“…Further animal studies by our group compared CC rates of 90/min and 120/min with similar time of ROSC 14. During CC carotid blood flow, mean arterial pressure, and % change in ejection fraction and cardiac output were higher in the CC+SI 90/min group compared with CC+SI 120/min 14. This further supports that higher CC rates do not improve systemic perfusion and that the current recommendation of 90 CC per minute are sufficient to achieve systemic perfusion.…”

“…However, the study used a higher rate during CC+SI which might have contributed to the faster ROSC. Further animal studies by our group compared CC rates of 90/min and 120/min with similar time of ROSC 14. During CC carotid blood flow, mean arterial pressure, and % change in ejection fraction and cardiac output were higher in the CC+SI 90/min group compared with CC+SI 120/min 14.…”

Optimal Chest Compression Rate and Compression to Ventilation Ratio in Delivery Room Resuscitation: Evidence from Newborn Piglets and Neonatal Manikins

“…Aaltonen et al (34) speculated that this drop in MAP could not be explained by a reduced left ventricular output. This is supported by results from Li et al (35) that cardiac output in asphyxiated newborn piglets after CPR was not different from control piglets. Thus, a more likely reason for hypotension in the asphyxic neonate is the profound acidosis and lack of substrate (ATP).…”

“…This is a plausible explanation for why attempts at increasing coronary perfusion by increasing the C:V ratio or even CC rate has not been successful in models of perinatal asphyxia. CCaV has not proven to be of benefit in asphyxiated piglets, unless they are combined with a sustained inflation (35, 37). Manikin studies support that continuous CC and asynchronous standard positive pressure ventilation might not provide benefit.…”

Chest Compressions during Sustained Inflations Improve Recovery When Compared to a 3:1 Compression:Ventilation Ratio during Cardiopulmonary Resuscitation in a Neonatal Porcine Model of Asphyxia

“…A mathematical model has also suggested that higher CC rates (as high as 180/min for term infants) could optimize systemic perfusion [10]. A recent randomized animal trial comparing CC+SI using CC rates of 90/min versus 120/min reported a similar time to ROSC and survival rate, and similar hemodynamic and respiratory parameters during CPR [17], suggesting that higher CC rates are not necessarily an advantage. In addition, recent simulation studies assessing fatigue reported that operators using CC rates of 120/min compared to 90/min showed signs of fatigue within 2 min of initiating CC [18,19].…”