The influence of the airway driving pressure on pulsed pressure variation as a predictor of fluid responsiveness

Objective  

Assessing pulse pressure variation (PPV) to predict fluid responsiveness in mechanically ventilated patients with tidal volume (VT) and the impact of VT and airway driving pressure (P_plat − PEEP) on the ability of PPV for predicting fluid responsiveness.     

Pulse pressure variation and volume responsiveness during acutely increased pulmonary artery pressure: an experimental study

Introduction  

We found that pulse pressure variation (PPV) did not predict volume responsiveness in patients with increased pulmonary artery pressure. This study tests the hypothesis that PPV does not predict fluid responsiveness during an endotoxin-induced acute increase in pulmonary artery pressure and right ventricular loading.     

Determinants of arterial and central venous blood pressure variation in ventilated critically ill children

Purpose  

Ventilation-induced arterial pressure variation predicts volume responsiveness in adults. Several factors are known to influence the interpretability of these variations. We analysed ventilation-induced variations in critically ill children with reference to ventilatory and circulatory parameters.     

Does the systolic pressure variation change in the prone position?

Objective  

The Systolic pressure variation (SPV) is known to be a sensitive indicator of hypovolemia. However, the SPV may be elevated due to other reasons, such as changes in lung compliance or tidal volumes. Using the SPV to monitor the hemodynamic status of patients in the prone position may, therefore, be problematic due to possible effects of increased abdominal pressure on both venous return and lung compliance. The purpose of this study is to examine whether or not the SPV changes significantly when placing the patient in the prone position.     

Pulse-pressure variation and hemodynamic response in patients with elevated pulmonary artery pressure: a clinical study

Introduction  

Pulse-pressure variation (PPV) due to increased right ventricular afterload and dysfunction may misleadingly suggest volume responsiveness. We aimed to assess prediction of volume responsiveness with PPV in patients with increased pulmonary artery pressure.     

Respiratory pulse pressure variation fails to predict fluid responsiveness in acute respiratory distress syndrome

Introduction  

Fluid responsiveness prediction is of utmost interest during acute respiratory distress syndrome (ARDS), but the performance of respiratory pulse pressure variation (Δ_RESPPP) has scarcely been reported. In patients with ARDS, the pathophysiology of Δ_RESPPP may differ from that of healthy lungs because of low tidal volume (Vt), high respiratory rate, decreased lung and sometimes chest wall compliance, which increase alveolar and/or pleural pressure. We aimed to assess Δ_RESPPP in a large ARDS population.     

Influence of respiratory rate and end-expiratory pressure variation on cyclic alveolar recruitment in an experimental lung injury model

Introduction  

Cyclic alveolar recruitment/derecruitment (R/D) is an important mechanism of ventilator-associated lung injury. In experimental models this process can be measured with high temporal resolution by detection of respiratory-dependent oscillations of the paO₂ (ΔpaO₂). A previous study showed that end-expiratory collapse can be prevented by an increased respiratory rate in saline-lavaged rabbits. The current study compares the effects of increased positive end-expiratory pressure (PEEP) versus an individually titrated respiratory rate (RR_ind) on intra-tidal amplitude of Δ paO₂ and on average paO₂ in saline-lavaged pigs.     

Use of expiratory change in bladder pressure to assess expiratory muscle activity in patients with large respiratory excursions in central venous pressure

Background  

Expiratory muscle activity may cause the end-expiratory central venous pressure (CVP) to greatly overestimate right atrial transmural pressure.     

Evaluation of mean systemic filling pressure from pulse contour cardiac output and central venous pressure

Objective  

The volemic status of a patient can be determined by measuring mean systemic filling pressure (Pmsf). Pmsf is obtained from the venous return curve, i.e. the relationship between central venous pressure (Pcv) and blood flow. We evaluated the feasibility and precision of Pmsf measurement.     

Interfaces for long-term noninvasive positive pressure ventilation in children

Objective  

The aim of the study was to report the type and tolerance of the interface chosen for long-term noninvasive positive pressure ventilation (NPPV) in children.     

Positive end-expiratory pressure affects the value of intra-abdominal pressure in acute lung injury/acute respiratory distress syndrome patients: a pilot study

Introduction  

To examine the effects of positive end-expiratory pressure (PEEP) on intra-abdominal pressure (IAP) in patients with acute lung injury (ALI).     

Tracheal pressure and endotracheal tube obstruction can be detected by continuous cuff pressure monitoring: in vitro pilot study

Purpose  

To evaluate whether the degree of endotracheal tube (ETT) obstruction can be predicted by changes of ETT cuff pressure (P _c) as a function of peak inspiratory pressure.     

Noninvasive intracranial pressure measurement using infrasonic emissions from the tympanic membrane

Objective  

We investigated whether ICP can be assessed by measuring infrasonic emissions from the tympanic membrane.     

In vivo accuracy of two intraparenchymal intracranial pressure monitors

Purpose  

To evaluate the in vivo accuracy of the new Pressio^? device for intraparenchymal monitoring of intracranial pressure (ICP) versus the Codman^? device and intraventricular measurement external ventricular drainage (EVD).     

Diurnal variation of melatonin and cortisol is maintained in non-septic intensive care patients

Objective  

To study the diurnal variation of melatonin and cortisol in critically ill patients and to assess whether the severity of organ dysfunction, sedation and sympathetic activity correlate with the production of these hormones.     

Mechanisms underlying center of pressure displacements in obese subjects during quiet stance

Objective  

the aim of this study was to assess whether reduced balance capacity in obese subjects is secondary to altered sensory information.     

Central venous pressure measurements improve the accuracy of leg raising-induced change in pulse pressure to predict fluid responsiveness

Purpose  

Passive leg raising (PLR) is a maneuver performed to test the cardiac Frank-Starling mechanism. We assessed the influence of PLR-induced changes in preload on the performance of PLR-induced change in pulse pressure (Δ_PLRPP) and cardiac output (Δ_PLRCO) for fluid responsiveness prediction.     

Efficacy of open-label counterconditioning for reducing nocebo effects on pressure pain

Background

Nocebo effects can adversely affect the experience of physical symptoms, such as pain and itch. Nocebo effects on itch and pain have shown to be induced by conditioning with thermal heat stimuli and reduced by counterconditioning. However, open-label counterconditioning, in which participants are informed about the placebo content of the treatment, has not been investigated, while this can be highly relevant for clinical practice. Furthermore, (open-label) conditioning and counterconditioning has not been investigated for pain modalities relevant to musculoskeletal disorders, such as pressure pain.

Methods

In a randomized controlled trial, we investigated in 110 healthy female participants whether nocebo effects on pressure pain combined with open-label verbal suggestions can be (1) induced via conditioning and (2) reduced via counterconditioning. Participants were allocated to either a nocebo- or sham-conditioning group. Next, the nocebo group was allocated to either counterconditioning, extinction or continued nocebo conditioning; sham conditioning was followed by placebo conditioning.

Results

Nocebo effects were significantly larger after nocebo conditioning than sham conditioning (d = 1.27). Subsequently, a larger reduction of the nocebo effect was found after counterconditioning than after extinction (d = 1.02) and continued nocebo conditioning (d = 1.66), with effects similar to placebo conditioning (following sham conditioning).

Conclusions

These results show that (counter)conditioning combined with open-label suggestions can modulate nocebo effects on pressure pain, which provides promise in designing learning-based treatments to reduce nocebo effects in patients with chronic pain disorders, particularly for musculoskeletal disorders.

Significance

Few studies have investigated the efficacy counterconditioning to reduce nocebo effects. Whereas typically deceptive procedures are used, these are not ethically appropriate for use in clinical practice. The current study demonstrates that open-label counterconditioning in a pain modality relevant for many chronic pain conditions may be a promising new strategy for reducing nocebo effects in a non-deceptive and ethical manner, which provides promise in designing learning-based treatments to reduce nocebo effects in patients with chronic pain disorders.     

Alveolar fluid clearance in healthy pigs and influence of positive end-expiratory pressure

Introduction  

The objectives were to characterize alveolar fluid clearance (AFC) in pigs with normal lungs and to analyze the effect of immediate application of positive end-expiratory pressure (PEEP).     

Changes in R-Wave amplitude in DII lead is less sensitive than pulse pressure variation to detect changes in stroke volume after fluid challenge in ICU patients postoperatively to cardiac surgery

Objective  

The amplitude of R-wave in DII lead (RDII) has been shown to correlate to central blood volume in animal and healthy volunteers. The aim of this study was to assess if change in RDII (ΔRDII) after passive leg rise (PLR) and fluid loading would allow detecting preload dependence in intensive care ventilated patients. This parameter was compared to concomitant changes in pulse arterial pressure (ΔPP).