Effect of residual leaning force on intrathoracic pressure during mechanical ventilation in children
ABSTRACT Determine the effect of residual leaning force on intrathoracic pressure (ITP) in healthy children receiving mechanical ventilation. We hypothesized that application of significant residual leaning force (2.5kg or 20% of subject body weight) would be associated with a clinically important change in ITP.
IRB-approved pilot study of healthy, anesthetized, paralyzed mechanically ventilated children (6 months to 7 years). Peak endotracheal pressure (ETP), a surrogate of ITP, was continuously measured before and during serial incremental increases in sternal force from 10% to 25% of the subject's body weight. A delta ETP of >or=2.0cmH(2)O was considered clinically significant.
13 healthy, anesthetized, paralyzed mechanically ventilated children (age: 26+/-24m, range: 6.5-87m; weight: 13+/-5kg, range: 7.4-24.8kg) were enrolled. Peak ETP increased from baseline for all force applications (10% body weight: mean difference of 0.8cmH(2)O, p<0.01; 15% body weight: mean difference of 1.1cmH(2)O, p<0.01; 20% body weight: mean difference of 1.5cmH(2)O, p<0.01; 25% body weight: mean difference of 1.89cmH(2)O, p<0.01). Residual leaning force of >or=2.5kg was associated with a 2.0cmH(2)O change in peak ETP (odds ratio 7.5; CI(95) 1.5-37.7; p=0.014) while sternal force >or=20% body weight was not (odds ratio 2.4; CI(95) 0.6-9.2; p=0.2).
In healthy anesthetized children, changes in ETP were detectable at residual leaning forces as low as 10% of subject body weight. Residual leaning force of 2.5kg was associated with increases in ETP >or=2.0cmH(2)O.
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ABSTRACT: BACKGROUND: Morbidity and mortality remain high following infant cardiac arrest. Optimal cardiopulmonary resuscitation (CPR) is therefore imperative. OBJECTIVE: Comparison of two-thumb (TT) and two-finger (TF) infant chest compression technique compliance with international recommendations. DESIGN: Randomised cross-over experimental study. METHODS: Twenty-two certified Advanced Paediatric Life Support (APLS) instructors performed 2 min continuous TT and TF chest compressions on an instrumented infant CPR manikin. Compression depth (CD), release force (RF), compression rate (CR) and duty cycles (DCs) were recorded. Quality indices were developed to calculate the proportion of compressions that complied with internationally recommended targets, and an overall quality index was used to calculate the proportion that complied with all four targets. RESULTS: Mean CD was 33 mm and 26 mm (p<0.001; target ≥36.7 mm), mean RF was 0.8 kg and 0.2 kg (p<0.001; target <2.5 kg), mean CR was 128/min and 131/min (p=0.052; target 100-120/min) and mean DCs was 61% and 53% (p<0.001; target 30-50%) for the TT and TF techniques, respectively. With the exception of RF, the majority of compressions failed to comply with targets. The TT technique improved median CD compliance (6% vs 0% (p<0.001)), while the TF technique improved median DC compliance (23% vs 0% (p<0.001)). Overall compliance with all four targets was <1% for both techniques (p=0.14). CONCLUSIONS: Compliance of APLS instructors with current international recommendations during simulated infant CPR is poor. The TT technique provided improved CD compliance, while the TF technique provided superior DC compliance. If this reflects current clinical practice, optimisation of performance to achieve international recommendations during infant CPR is called for.Archives of Disease in Childhood 11/2012; 98(8). DOI:10.1136/archdischild-2012-302583 · 2.91 Impact Factor
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ABSTRACT: Force due to leaning during cardiopulmonary resuscitation (CPR) negatively affects haemodynamics and intrathoracic airway pressures (ITP) in animal models and adults, but has not been studied in children. We sought to characterize the effects of sternal force (SF) comparable to leaning force on hemodynamics and ITP in anaesthetized children. Children (6 mos-8 yrs) presenting for routine haemodynamic cardiac catheterization with anaesthesia and mechanical ventilation >6 mos after cardiac transplant were studied. Haemodynamics and ITP were measured before and during incremental increases in SF of 10% and 20% body weight. Results: 20 subjects (5.4±1.7 yrs of age and 18.3±3.3kg) were studied. Mean right atrial pressure (6.5±2.6 at baseline v. 7.7±2.6 at 10% SF v. 8.6±2.7mmHg at 20% SF), mean pulmonary capillary wedge pressure (10.2±2.9 at baseline v. 11±3.3 at 10% SF v. 11.8±3.4mmHg at 20% SF) and ITP (16.3±3.2 at baseline v. 17.9±3.9 at 10% SF v. 19.5±4cm H2O) all increased significantly with incremental SF (p<0.001 for all). Aortic systolic pressure (85±10mmHg at baseline v. 83±10mmHg at 10% SF v. 82±10mmHg at 20% SF, p=0.014) and coronary perfusion pressure (42±7mmHg at baseline v. 39±7mmHg at 10% SF v. 38±7mmHg at 20% SF, p<0.001) both decreased significantly with incremental SF. In asymptomatic, anaesthetized children after cardiac transplantation, sternal forces comparable to leaning previously reported to occur during CPR elevate ITP and right atrial pressure and decrease coronary perfusion pressure. These haemodynamic effects may be clinically important during CPR and warrant further study.Resuscitation 07/2013; DOI:10.1016/j.resuscitation.2013.07.010 · 3.96 Impact Factor
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ABSTRACT: The "2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" increased the focus on methods to ensure that high-quality cardiopulmonary resuscitation (CPR) is performed in all resuscitation attempts. There are 5 critical components of high-quality CPR: minimize interruptions in chest compressions, provide compressions of adequate rate and depth, avoid leaning between compressions, and avoid excessive ventilation. Although it is clear that high-quality CPR is the primary component in influencing survival from cardiac arrest, there is considerable variation in monitoring, implementation, and quality improvement. As such, CPR quality varies widely between systems and locations. Victims often do not receive high-quality CPR because of provider ambiguity in prioritization of resuscitative efforts during an arrest. This ambiguity also impedes the development of optimal systems of care to increase survival from cardiac arrest. This consensus statement addresses the following key areas of CPR quality for the trained rescuer: metrics of CPR performance; monitoring, feedback, and integration of the patient's response to CPR; team-level logistics to ensure performance of high-quality CPR; and continuous quality improvement on provider, team, and systems levels. Clear definitions of metrics and methods to consistently deliver and improve the quality of CPR will narrow the gap between resuscitation science and the victims, both in and out of the hospital, and lay the foundation for further improvements in the future.Circulation 06/2013; 128(4). DOI:10.1161/CIR.0b013e31829d8654 · 14.95 Impact Factor