Journal of critical care最新文献

Purpose

Materials and methods

Results

Conclusions

Purpose

Materials and methods

Results

Conclusion

Background

Hemoglobin‑oxygen (Hb-O₂) affinity is an important determinant for oxygen delivery and oxygen extraction. Although cardiovascular agents such as noradrenaline, adrenaline, atropine, milrinone and levosimendan are widely used in intensive care units worldwide, nothing is known about their possible effects on Hb-O₂ affinity.

Methods

In this experimental ex-vivo trial, venous blood samples were taken from 5 male and 6 female volunteers and incubated with the particular cardiovascular agents. Oxygen dissociation curves (ODC) were measured in-vitro with a new high-throughput method.

Results

Compared to the P₅₀ in male and female controls, a significant right-shift of the ODC was found for noradrenaline and milrinone in all participants and for levosimendan in male samples only. Adrenaline decreased Hb-O₂ affinity in male samples, atropine in female samples only.

Discussion

All investigated agents decreased Hb-O₂ affinity, with marked differences between males and females. Although the underlying mechanisms remain unclear, the extent of these effects may increase oxygen extraction at the tissue level as long as pulmonary oxygen uptake is maintained.

Purpose

To investigate the frequency, content, and clinical translation of advance directives in intensive care units (ICUs).

Material and methods

Retrospective cohort study in a Swiss tertiary ICU, including patients with advance directives treated in ICUs ≥48 h. The primary endpoint was the violation of directives. Key secondary endpoints were the directives' prevalence and their translation into clinical practice.

Results

Of 5′851 patients treated ≥48 h in ICUs, 2.7 % had documented directives. Despite 92 % using templates, subjective or contradictory wording was found in 19 % and 12 %. Nine percent of directives were violated. Patients with directive violations had worse in-hospital outcomes (p = 0.012). At admission, 64 % of patients experiencing violations could not communicate, and directives were missing/unrecognized in 30 %. Mostly, directives were not followed regarding life-prolonging measures (6 %), ICU admission (5 %), and mechanical ventilation (3 %). Kaplan Meier statistics revealed a lower survival rate with directives recognized at admission (p = 0.04) and when treatment was withheld (p < 0.001).

Conclusions

Advance directives are available in a minority of ICU patients and often contain subjective/contradictory wording. Physicians respected directives in 90 % of patients, with treatment adapted following their wishes. However, violation of directives may have serious consequences with unfavorable in-hospital outcomes and decreased long-term survival with treatment adaption following directives.

Mechanical ventilation stands as a life-saving intervention in the management of respiratory failure. However, it carries the risk of ventilator-induced lung injury. Despite the adoption of lung-protective ventilation strategies, including lower tidal volumes and pressure limitations, mortality rates remain high, leaving room for innovative approaches. The concept of mechanical power has emerged as a comprehensive metric encompassing key ventilator parameters associated with the genesis of ventilator-induced lung injury, including volume, pressure, flow, resistance, and respiratory rate. While numerous animal and human studies have linked mechanical power and ventilator-induced lung injury, its practical implementation at the bedside is hindered by calculation challenges, lack of equation consensus, and the absence of an optimal threshold. To overcome the constraints of measuring static respiratory parameters, dynamic mechanical power is proposed for all patients, regardless of their ventilation mode. However, establishing a causal relationship is crucial for its potential implementation, and requires further research. The objective of this review is to explore the role of mechanical power in ventilator-induced lung injury, its association with patient outcomes, and the challenges and potential benefits of implementing a ventilation strategy based on mechanical power.

Background

Recent guidelines for post-cardiac arrest (CA) management have undergone significant changes regarding targeted therapeutic management (TTM), transitioning from hypothermia to temperature control. We aimed to assess changes in post-CA management in French intensive care units following the new recommendations.

Methods

Two declarative web surveys were conducted from March to August 2023. We compared the doctors' survey to that previously published in 2015. We contacted 389 departments from 276 French centers.

Results

Three hundred thirty-four physicians from 189 distinct ICUs departments participated in the survey. TTM was used by 95.5 % of respondents. TTM with temperature feedback device was used by 64 % of respondents. In multivariate analysis, use of TTM with temperature feedback was associated with university hospital responder [OR 1.99 (1.19–3.34, p = 0.009)], high CA admissions rate [OR 2.25 (1.13–4.78, p = 0.026)], use of a written CA procedure [OR 1.76 (1.07–2.92, p = 0.027)] and presence of a cath-lab performing coronary angiography [OR 2.42 (1.33–4.44, p = 0.004)]. The targeted temperature rose from 32 to 34 °C in 2015, to 35–36 °C in 2023 (p < 0.001). Proportions of TTM with temperature feedback devices switched from 45 % to 65 % (p < 0.001). 660 nurses responses from 150 ICUs were analyzed. According to TTM users, gel-coated water circulating pads and intravascular cooling were considered the most effective devices and were found to be easily adjustable.

Conclusions

These surveys provide insights into post-resuscitation care and TTM practice in France. One year after their publication, the latest recommendations concerning TTM have not been fully implemented, as the majority of ICUs continue to use moderate hypothermia. They widely reported employing specific TTM, with the use of TTM with temperature feedback devices increasing significantly. Heterogeneity exists regarding the TTM systems used, with a significant proportion lacking temperature feedback. This aspect requires specific attention, depending on local constraints and devices costs.

This study investigated fluid removal strategies for critically ill patients with fluid overload on mechanical ventilation. Traditionally, a negative fluid balance (FB) is aimed for. However, this approach can have drawbacks. Here, we compared a new approach, namely removing fluids until patients become fluid responsive (FR) to the traditional empiric negative balance approach.

Twelve patients were placed in each group (n = 24). FR assessment was performed using passive leg raising (PLR). Both groups maintained stable blood pressure and heart function during fluid management. Notably, the FR group weaned from the ventilator significantly faster than negative FB group (both for a spontaneous breathing trial (14 h vs. 36 h, p = 0.031) and extubation (26 h vs. 57 h, p = 0.007); the difference in total ventilator time wasn't statistically significant (49 h vs. 62 h, p = 0.065). Additionally, FR group avoided metabolic problems like secondary alkalosis and potential hypokalemia seen in the negative FB group.

FR-guided fluid-removal in fluid overloaded mechanically ventilated patients was a feasible, safe, and maybe superior strategy in facilitating weaning and disconnection from mechanical ventilation than negative FB-driven fluid removal. FR is a safe endpoint for optimizing cardiac function and preventing adverse consequences during fluid removal.