Continuous Noninvasive Blood Pressure Measurement With "ClearSight" Compared to Standard Intermittent Blood Pressure Measurement in Patients With Peripheral Arterial Disease. Are Potential Differences Influenced by Phenylephrine or Dobutamine?

OBJECTIVES: To investigate the agreement between continuous noninvasive blood pressure measurement with the ClearSight system (cNIBP-CS) and standard intermittent noninvasive blood pressure measurement (iNIBP) in patients with peripheral arterial disease (PAD). Additionally, the influence of vasoactive medication on potential measurement differences was assessed. DESIGN: A secondary analysis of a randomized controlled trial. SETTING: At a university hospital. PARTICIPANTS: Thirty-four patients with PAD undergoing percutaneous transluminal angioplasty of the lower limbs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Continuous noninvasive blood pressures were measured with the "ClearSight" system and compared to standard iNIBPs. Bland-Altman analysis revealed a mean bias of 13 mmHg (±15) between cNIBP-CS and iNIBP, with 95% limits of agreement (LOA) ranging from -17 to 42 mmHg. When comparing both medication groups, a similar mean bias was found for phenylephrine and dobutamine (12 mmHg [±13] and 13 mmHg [±13], respectively). CONCLUSION: In this study, in patients with PAD, cNIBP-CS showed an underestimation of blood pressure compared to iNIBP in phenylephrine- and dobutamine-treated patients. Compared to previous studies, a larger bias and wider 95% LOA were found.

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.

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.