Transient electrocardiographic abnormalities following blunt chest trauma in a child

Blunt cardiac injury may occur in patients after suffering nonpenetrating trauma of the chest. It encompasses a wide spectrum of cardiac injury with varied severity and clinical presentation. Electrocardiographic abnormalities are frequently encountered. This article presents a case of a child who presented with complete right bundle branch block on the initial ECG at the emergency department. She suffered blunt chest trauma during a horseback riding accident. She was admitted for cardiac monitoring. The electrocardiographic abnormalities resolved within 12 hours. No signs of myocardial injury were found on repeat serum troponin measurement and echocardiography. The natural history of ECG abnormalities in the pediatric age group following blunt chest trauma is limited. Although a complete right bundle branch block may be transient in adult patients, this has not been previously reported in a children. Significant ECG abnormalities can be encountered in children following blunt chest trauma. Although a complete RBBB can be associated with severe injury to the RV, it can also occur with minor injury. Keywords Cardiac contusio

Unloading work of breathing during high-frequency oscillatory ventilation: a bench study

INTRODUCTION: With the 3100B high-frequency oscillatory ventilator (SensorMedics, Yorba Linda, CA, USA), patients' spontaneous breathing efforts result in a high level of imposed work of breathing (WOB). Therefore, spontaneous breathing often has to be suppressed during high-frequency oscillatory ventilation (HFOV). A demand-flow system was designed to reduce imposed WOB. METHODS: An external gas flow controller (demand-flow system) accommodates the ventilator fresh gas flow during spontaneous breathing simulation. A control algorithm detects breathing effort and regulates the demand-flow valve. The effectiveness of this system has been evaluated in a bench test. The Campbell diagram and pressure time product (PTP) are used to quantify the imposed workload. RESULTS: Using the demand-flow system, imposed WOB is considerably reduced. The demand-flow system reduces inspiratory imposed WOB by 30% to 56% and inspiratory imposed PTP by 38% to 59% compared to continuous fresh gas flow. Expiratory imposed WOB was decreased as well by 12% to 49%. In simulations of shallow to normal breathing for an adult, imposed WOB is 0.5 J l(-1 )at maximum. Fluctuations in mean airway pressure on account of spontaneous breathing are markedly reduced. CONCLUSION: The use of the demand-flow system during HFOV results in a reduction of both imposed WOB and fluctuation in mean airway pressure. The level of imposed WOB was reduced to the physiological range of WOB. Potentially, this makes maintenance of spontaneous breathing during HFOV possible and easier in a clinical setting. Early initiation of HFOV seems more possible with this system and the possibility of weaning of patients directly on a high-frequency oscillatory ventilator is not excluded either

Imposed work of breathing during high-frequency oscillatory ventilation: a bench study

INTRODUCTION: The ventilator and the endotracheal tube impose additional workload in mechanically ventilated patients breathing spontaneously. The total work of breathing (WOB) includes elastic and resistive work. In a bench test we assessed the imposed WOB using 3100 A/3100 B SensorMedics high-frequency oscillatory ventilators. METHODS: A computer-controlled piston-driven test lung was used to simulate a spontaneously breathing patient. The test lung was connected to a high-frequency oscillatory ventilation (HFOV) ventilator by an endotracheal tube. The inspiratory and expiratory airway flows and pressures at various places were sampled. The spontaneous breath rate and volume, tube size and ventilator settings were simulated as representative of the newborn to adult range. The fresh gas flow rate was set at a low and a high level. The imposed WOB was calculated using the Campbell diagram. RESULTS: In the simulations for newborns (assumed body weight 3.5 kg) and infants (assumed body weight 10 kg) the imposed WOB (mean ± standard deviation) was 0.22 ± 0.07 and 0.87 ± 0.25 J/l, respectively. Comparison of the imposed WOB in low and high fresh gas flow rate measurements yielded values of 1.63 ± 0.32 and 0.96 ± 0.24 J/l (P = 0.01) in small children (assumed body weight 25 kg), of 1.81 ± 0.30 and 1.10 ± 0.27 J/l (P < 0.001) in large children (assumed body weight 40 kg), and of 1.95 ± 0.31 and 1.12 ± 0.34 J/l (P < 0.01) in adults (assumed body weight 70 kg). High peak inspiratory flow and low fresh gas flow rate significantly increased the imposed WOB. Mean airway pressure in the breathing circuit decreased dramatically during spontaneous breathing, most markedly at the low fresh gas flow rate. This led to ventilator shut-off when the inspiratory flow exceeded the fresh gas flow. CONCLUSION: Spontaneous breathing during HFOV resulted in considerable imposed WOB in pediatric and adult simulations, explaining the discomfort seen in those patients breathing spontaneously during HFOV. The level of imposed WOB was lower in the newborn and infant simulations, explaining why these patients tolerate spontaneous breathing during HFOV well. A high fresh gas flow rate reduced the imposed WOB. These findings suggest the need for a demand flow system based on patient need allowing spontaneous breathing during HFOV

Heliox reduces respiratory system resistance in respiratory syncytial virus induced respiratory failure

Introduction Respiratory syncytial virus (RSV) lower respiratory tract disease is characterised by narrowing of the airways resulting in increased airway resistance, air-trapping and respiratory acidosis. These problems might be overcome using helium-oxygen gas mixture. However, the effect of mechanical ventilation with heliox in these patients is unclear. The objective of this prospective cross-over study was to determine the effects of mechanical ventilation with heliox 60/40 versus conventional gas on respiratory system resistance, air-trapping and CO2 removal. Methods Mechanically ventilated, sedated and paralyzed infants with proven RSV were enrolled within 24 hours after paediatric intensive care unit (PICU) admission. At T = 0, respiratory system mechanics including respiratory system compliance and resistance, and peak expiratory flow rate were measured with the AVEA ventilator. The measurements were repeated at each interval (after 30 minutes of ventilation with heliox, after 30 minutes of ventilation with nitrox and again after 30 minutes of ventilation with heliox). Indices of gas exchange (ventilation and oxygenation index) were calculated at each interval. Air-trapping (defined by relative change in end-expiratory lung volume) was determined by electrical impedance tomography (EIT) at each interval. Results Thirteen infants were enrolled. In nine, EIT measurements were performed. Mechanical ventilation with heliox significantly decreased respiratory system resistance. This was not accompanied by an improved CO2 elimination, decreased peak expiratory flow rate or decreased end-expiratory lung volume. Importantly, oxygenation remained unaltered throughout the experimental protocol. Conclusions Respiratory system resistance is significantly decreased by mechanical ventilation with helio

Primary management and treatment of paediatric septic shock

Paediatric shock is common. Hypovolaemic and septic shock are the main forms. Early and rapid results-oriented therapy of paediatric septic shock has a favourable effect on survival. There is an international guideline for the primary management of paediatric shock during the first hour after presentation of the patient. The goal of treatment is to prevent oxygen debt and consequently organ failure. The main symptoms of paediatric shock are tachycardia and reduced consciousness. In a child in shock, the clinical picture should be recognized within 15 minutes and an attempt should be made to reverse the situation by rapid fluid infusion. If the shock persists after 15 minutes, vasoactive medication should be given and the child should be transferred to a local paediatric intensive care unit. Intubation and mechanical ventilation are then also required.</p