Do manual chest compressions provide substantial ventilation during prehospital cardiopulmonary resuscitation?

INTRODUCTION: Chest compressions have been suggested to provide passive ventilation during cardiopulmonary resuscitation. Measurements of this passive ventilatory mechanism have only been performed upon arrival of out-of-hospital cardiac arrest patients in the emergency department. Lung and thoracic characteristics rapidly change following cardiac arrest, possibly limiting the effectiveness of this mechanism after prolonged resuscitation efforts. Goal of this study was to quantify passive inspiratory tidal volumes generated by manual chest compression during prehospital cardiopulmonary resuscitation. MATERIALS AND METHODS: A flowsensor was used during adult out-of-hospital cardiac arrest cases attended by a prehospital medical team. Adult, endotracheally intubated, non-traumatic cardiac arrest patients were eligible for inclusion. Immediately following intubation, the sensor was connected to the endotracheal tube. The passive inspiratory tidal volumes generated by the first thirty manual chest compressions performed following intubation (without simultaneous manual ventilation) were calculated. RESULTS: 10 patients (5 female) were included, median age was 64 years (IQR 56, 77 years). The median compression frequency was 111 compression per minute (IQR 107, 116 compressions per minute). The median compression depth was 5.6 cm (IQR 5.4 cm, 6.1 cm). The median inspiratory tidal volume generated by manual chest compressions was 20 mL (IQR 13, 28 mL). CONCLUSION: Using a flowsensor, passive inspiratory tidal volumes generated by manual chest compressions during prehospital cardiopulmonary resuscitation, were quantified. Chest compressions alone appear unable to provide adequate alveolar ventilation during prehospital treatment of cardiac arrest.

Chest compressions during ventilation in out-of-hospital cardiac arrest cause reversed airflow.

AIM: During cardiopulmonary resuscitation, once the patient is intubated, compressions and ventilations are performed simultaneously. Chest compressions during the inspiratory phase of ventilation may force air out of the lungs, causing so-called "reversed airflow", which may lead to ineffective ventilation. The purpose of this study is to determine the occurrence of this phenomenon and to quantify the volume of reversed airflow. METHODS: Observational study. During manual ventilation of intubated patients receiving chest compressions, the pressure gradient over the endotracheal tube was measured using two air-filled catheters connected to a custom-made portable device. Chest compression data were measured using an accelerometer on a Zoll E- series defibrillator. All data are reported as mean (standard deviation; range). RESULTS: Twenty-five patients and a total of 368 ventilations were studied, on average 15 (6; 10-30) per patient. The mean tidal volume, minute volume and ventilation rate were respectively 690 ml (160; 240-1260), 10.5 l/min (4.8; 4.4-22.1) and 18/min (6; 6-35). Reversed airflow was observed in 21/25 patients (84%) and in 65% of all ventilations, with on average two episodes per ventilation. Fifty-five percent of the chest compressions during the inspiratory phase of the ventilation generated reversed airflow. The mean volume of the reversed airflow was 96 ml per episode (52; 12-364). CONCLUSION: Chest compressions during ventilation in intubated patients generated reversed airflow in most patients. There was wide variation in the number of episodes and volume of the reversed airflow between patients. The effect of this phenomenon on the efficacy of ventilation during resuscitation and on outcome needs further investigation.

Patient safety incidents during interhospital transport of patients: A prospective analysis.

INTRODUCTION: Interhospital transport of critically ill patients is at risk of complications. The objective of the study was to prospectively record patient safety incidents that occurred during interhospital transports and to determine their risk factors. METHODS: We prospectively collected data during a fifteen-month period in 2 hospitals. Patient and transport characteristics were collected using a specifically designed tool. Patient safety incidents were appraised for health-care associated harm, and categorized as technical, operational, and communication problems. RESULTS: Our study included 688 patients who were transferred to or from one of both hospitals by physician or nurse led transport, with complete records. A patient safety incident was reported in 16.7% of transports, health-care associated harm was noted in 3.9% of cases. In multivariate analysis, three factors remained significantly associated with an increased risk of healthcare-associated harm: operational incidents (odds ratio=144.93, 95% CI=37.55-767.50, P<0.001), communication incidents (odds ratio=11.05, 95% CI=3.02-52.99, P<0.001) and the Modified Sequential Organ Failure Assessment (M-SOFA) score (odds ratio=1.198, 95% CI=1.038-1.40, P=0.017). CONCLUSIONS: The observed rate of patient safety incidents during interhospital transfers is lower than previously reported in the literature. However, there is limited previous work done on this topic. Operational and communication incidents, and a higher M-SOFA score are significantly associated with increase odds of harmful incident. These findings call for stricter preparation of transfers, with clear and standardized communication.

Detection and quantification of gasping during resuscitation for out-of-hospital cardiac arrest.

AIM: To detect and quantify gasping during cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA) patients and to investigate whether gasping is associated with increased return of spontaneous circulation (ROSC). MATERIALS AND METHODS: A prospective observational study in patients resuscitated and mechanically or manually ventilated for OHCA by emergency physicians of Ghent University Hospital. After intubation, pressure catheters were inserted in the endotracheal tube (ETT) and pressures were measured at the proximal and distal ends of the ETT. Gasping was analysed with custom-developed software and volumes were calculated based on pressure differences between the catheters. Data are expressed as median (interquartile range). RESULTS: Data were collected in 292 resuscitated patients of whom 36.2% achieved ROSC. Seventy-six of 292 (26.0%) patients showed gasping on the pressure curves during resuscitation. The median gasping volume was 274ml (196-434). The median gasping rate was 3.7 gasps/min (1.5-7.3). Gasping occurred significantly more in patients displaying ventricular fibrillation as the initial rhythm compared to patients with pulseless electrical activity, pulseless ventricular tachycardia or asystole. The median gasping rate was significantly higher in the ROSC group compared to the non-ROSC group (11.8 gasps/min (95% CI [4.2, 13.9]) and 2.8 gasps/min (95% CI [1.7, 3.9]) respectively (P<0.001)). A gasping rate of >7.3 gasps/min appeared to be the optimal criterion value to herald ROSC. Deeper negative pressures were associated with an increased incidence of ROSC (P=0.011). There was no significant difference in ROSC between patients with gasping and those without. CONCLUSION: The occurrence of gasping during CPR was high. Significant gasping volumes were measured. The presence or absence of gasping was not associated with ROSC, but higher gasping rate and deeper negative pressures were.