OBJECTIVES:To evaluate the ability of central venous-to-arterial carbon dioxide pressure difference, central venous oxygen saturation, and the combination of these two parameters to detect extubation ...failure in critically ill patients.
DESIGN:Multicentric, prospective, observational study.
SETTING:Three ICUs.
PATIENTS:All patients who received mechanical ventilation for more than 48 hours and tolerated spontaneous breathing trials with a T-piece for 60 minutes.
INTERVENTIONS:Extubation after successful spontaneous breathing trials. Extubation failure was defined as the need for mechanical ventilation within 48 hours.
MEASUREMENTS AND MAIN RESULTS:The oxygen delivery index, oxygen consumption index, central venous oxygen saturation, central venous-to-arterial carbon dioxide pressure difference, and oxygen extraction were measured immediately before spontaneous breathing trials and at 60 minutes after spontaneous breathing trials initiation. Seventy-five patients were enrolled, and extubation failure was noted in 18 (24%) patients. Oxygen consumption index increased significantly during spontaneous breathing trials in the failure group. Oxygen delivery index increased in both success and failure groups. Oxygen extraction increased in the failure group (p = 0.005) and decreased in the success group (p = 0.001). Central venous oxygen saturation decreased in the failure group and increased in the success group (p = 0.014). ΔPCO2 value increased in the extubation failure group and decreased in the success group (p = 0.002). Changes in ΔPCO2 (Δ – ΔPCO2) and central venous oxygen saturation (ΔScvO2) during spontaneous breathing trials were independently associated with extubation failure (odds ratio, 1.02; 95% CI, 1.01–1.05; p = 0.006, and odds ratio, 0.84; 95% CI, 0.70–0.95; p = 0.02, respectively). Δ – ΔPCO2 and central venous oxygen saturation could predict extubation failure with areas under the curve of 0.865 and 0.856, respectively; however, their combined areas under the curve was better at 0.940.
CONCLUSIONS:We found that Δ – ΔPCO2 and central venous oxygen saturation, during spontaneous breathing trials, were independent predictors of weaning outcomes. Combination analysis of both parameters enhanced their diagnostic performance and provided excellent predictability in extubation failure detection in critically ill patients.
Objectives:
To evaluate the ability of central venous-to-arterial carbon dioxide pressure difference, central venous oxygen saturation, and the combination of these two parameters to detect ...extubation failure in critically ill patients.
Design:
Multicentric, prospective, observational study.
Setting:
Three ICUs.
Patients:
All patients who received mechanical ventilation for more than 48 hours and tolerated spontaneous breathing trials with a T-piece for 60 minutes.
Interventions:
Extubation after successful spontaneous breathing trials. Extubation failure was defined as the need for mechanical ventilation within 48 hours.
Measurements and Main Results:
The oxygen delivery index, oxygen consumption index, central venous oxygen saturation, central venous-to-arterial carbon dioxide pressure difference, and oxygen extraction were measured immediately before spontaneous breathing trials and at 60 minutes after spontaneous breathing trials initiation. Seventy-five patients were enrolled, and extubation failure was noted in 18 (24%) patients. Oxygen consumption index increased significantly during spontaneous breathing trials in the failure group. Oxygen delivery index increased in both success and failure groups. Oxygen extraction increased in the failure group (
p
= 0.005) and decreased in the success group (
p
= 0.001). Central venous oxygen saturation decreased in the failure group and increased in the success group (
p
= 0.014). ΔP
co2
value increased in the extubation failure group and decreased in the success group (
p
= 0.002). Changes in ΔP
co2
(Δ – ΔPCO
2
) and central venous oxygen saturation (ΔScvO
2
) during spontaneous breathing trials were independently associated with extubation failure (odds ratio, 1.02; 95% CI, 1.01–1.05;
p
= 0.006, and odds ratio, 0.84; 95% CI, 0.70–0.95;
p
= 0.02, respectively). Δ – ΔPCO
2
and central venous oxygen saturation could predict extubation failure with areas under the curve of 0.865 and 0.856, respectively; however, their combined areas under the curve was better at 0.940.
Conclusions:
We found that Δ – ΔP
co
2
and central venous oxygen saturation, during spontaneous breathing trials, were independent predictors of weaning outcomes. Combination analysis of both parameters enhanced their diagnostic performance and provided excellent predictability in extubation failure detection in critically ill patients.
IntroductionA palliative approach to intensive care unit (ICU) patients with acute respiratory failure and a do-not-intubate order corresponds to a poorly evaluated target for non-invasive ...oxygenation treatments. Survival alone should not be the only target; it also matters to avoid discomfort and to restore the patient’s quality of life. We aim to conduct a prospective multicentre observational study to analyse clinical practices and their impact on outcomes of palliative high-flow nasal oxygen therapy (HFOT) and non-invasive ventilation (NIV) in ICU patients with do-not-intubate orders.Methods and analysisThis is an investigator-initiated, multicentre prospective observational cohort study comparing the three following strategies of oxygenation: HFOT alone, NIV alternating with HFOT and NIV alternating with standard oxygen in patients admitted in the ICU for acute respiratory failure with a do-not-intubate order. The primary outcome is the hospital survival within 14 days after ICU admission in patients weaned from NIV and HFOT. The sample size was estimated at a minimum of 330 patients divided into three groups according to the oxygenation strategy applied. The analysis takes into account confounding factors by modelling a propensity score.Ethics and disseminationThe study has been approved by the ethics committee and patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals.Trial registration numberNCT03673631
Background
To evaluate the ability of the central venous-to-arterial CO
2
content and tension differences to arteriovenous oxygen content difference ratios (∆ContCO
2
/∆ContO
2
and ∆PCO
2
/∆ContO
2
, ...respectively), blood lactate concentration, and central venous oxygen saturation (ScvO
2
) to detect the presence of global anaerobic metabolism through the increase in oxygen consumption (VO
2
) after an acute increase in oxygen supply (DO
2
) induced by volume expansion (VO
2
/DO
2
dependence).
Methods
We prospectively studied 98 critically ill mechanically ventilated patients in whom a fluid challenge was decided due to acute circulatory failure related to septic shock. Before and after volume expansion (500 mL of colloid solution), we measured cardiac index, VO
2
, DO
2
, ∆ContCO
2
/∆ContO
2
and ∆PCO
2
/∆ContO
2
ratios, lactate, and ScvO
2
. Fluid-responders were defined as a ≥15 % increase in cardiac index. Areas under the receiver operating characteristic curves (AUC) were determined for these variables.
Results
Fifty-one patients were fluid-responders (52 %). DO
2
increased significantly (31 ± 12 %) in these patients. An increase in VO
2
≥ 15 % (“VO
2
-responders”) concurrently occurred in 57 % of the 51 fluid-responders (45 ± 16 %). Compared with VO
2
-non-responders, VO
2
-responders were characterized by higher lactate levels and higher ∆ContCO
2
/∆ContO
2
and ∆PCO
2
/∆ContO
2
ratios. At baseline, lactate predicted a fluid-induced increase in VO
2
≥ 15 % with AUC of 0.745. Baseline ∆ContCO
2
/∆ContO
2
and ∆PCO
2
/∆ContO
2
ratios predicted an increase of VO
2
≥ 15 % with AUCs of 0.965 and 0.962, respectively. Baseline ScvO
2
was not able to predict an increase of VO
2
≥ 15 % (AUC = 0.624).
Conclusions
∆ContCO
2
/∆ContO
2
and ∆PCO
2
/∆ContO
2
ratios are more reliable markers of global anaerobic metabolism than lactate. ScvO
2
failed to predict the presence of global tissue hypoxia.
Targeted temperature management (TTM) currently is the only treatment with demonstrated efficacy in attenuating the harmful effects on the brain of ischemia-reperfusion injury after cardiac arrest. ...However, whether TTM is beneficial in the subset of patients with in-hospital cardiac arrest (IHCA) remains unclear.
Is TTM at 33 °C associated with better neurological outcomes after IHCA in a nonshockable rhythm compared with targeted normothermia (TN; 37 °C)?
We performed a post hoc analysis of data from the published Targeted Temperature Management for Cardiac Arrest with Nonshockable Rhythm randomized controlled trial in 584 patients. We included the 159 patients with IHCA; 73 were randomized to 33 °C treatment and 86 were randomized to 37 °C treatment. The primary outcome was survival with a good neurologic outcome (cerebral performance category CPC score of 1 or 2) on day 90. Mixed multivariate adjusted logistic regression analysis was performed to determine whether survival with CPC score of 1 or 2 on day 90 was associated with type of temperature management after adjustment on baseline characteristics not balanced by randomization.
Compared with TN for 48 h, hypothermia at 33 °C for 24 h was associated with a higher percentage of patients who were alive with good neurologic outcomes on day 90 (16.4% vs 5.8%; P = .03). Day 90 mortality was not significantly different between the two groups (68.5% vs 76.7%; P = .24). By mixed multivariate analysis adjusted by Cardiac Arrest Hospital Prognosis score and circulatory shock status, hypothermia was associated significantly with good day 90 neurologic outcomes (OR, 2.40 95% CI, 1.17-13.03; P = .03).
Hypothermia at 33 °C was associated with better day 90 neurologic outcomes after IHCA in a nonshockable rhythm compared with TN. However, the limited sample size resulted in wide CIs. Further studies of patients after cardiac arrest resulting from any cause, including IHCA, are needed.
The objective of this study was to examine the repeatability of blood gas (BG) parameters and their derived variables such as the central venous-to-arterial carbon dioxide tension difference (▵PCO2) ...and the ratio of ▵PCO2 over the central arteriovenous oxygen content difference (▵PCO2/C(a-cv)O2) and to determine the smallest detectable changes in individual patients.A total of 192 patients with arterial and central venous catheters were included prospectively. Two subsequent arterial and central venous blood samples were collected immediately one after the other and analyzed using the same point-of-care BG analyzer. The samples were analyzed for arterial and venous BG parameters, ▵PCO2, and ▵PCO2/C(a-cv)O2 ratio. Repeatability was expressed as the smallest detectable difference (SDD) and the least significant change (LSC). A change in value of these parameters exceeding the SDD or the LSC should be regarded as real.The SDDs for arterial carbon dioxide tension, arterial oxygen saturation, central venous oxygen saturation (ScvO2), and ▵PCO2 were small: ±2.06 mm Hg, ±1.23%, 2.92%, and ±1.98 mm Hg, respectively, whereas the SDDs for arterial oxygen tension (PaO2) and ▵PCO2/C(a-cv)O2 were high: ±9.09 mm Hg and ±0.57 mm Hg/mL, respectively. The LSCs (%) for these variables were 5.06, 1.27, 4.44, 32.4, 9.51, and 38.5, respectively.The repeatability of all these variables was good except for PaO2 and ▵PCO2/C(a-cv)O2 ratio for which we observed an important inherent variability. Expressed as SDD, a ScvO2 change value of at least ±3% should be considered as true. The clinician must be aware that an apparent change in these variables in an individual patient might represent only an inherent variation.
To evaluate the impact of switching to total face mask in cases where face mask-delivered noninvasive mechanical ventilation has already failed in do-not-intubate patients in acute respiratory ...failure.
Prospective observational study in an ICU and a respiratory stepdown unit over a 12-month study period.
Switching to total face mask, which covers the entire face, when noninvasive mechanical ventilation using facial mask (oronasal mask) failed to reverse acute respiratory failure.
Seventy-four patients with a do-not-intubate order and treated by noninvasive mechanical ventilation for acute respiratory failure.
Failure of face mask-delivered noninvasive mechanical ventilation was associated with a three-fold increase in in-hospital mortality (36% vs. 10.5%; p = 0.009). Nevertheless, 23 out of 36 patients (64%) in whom face mask-delivered noninvasive mechanical ventilation failed to reverse acute respiratory failure and, therefore, switched to total face mask survived hospital discharge. Reasons for switching from facial mask to total face mask included refractory hypercapnic acute respiratory failure (n = 24, 66.7%), painful skin breakdown or facial mask intolerance (n = 11, 30%), and refractory hypoxemia (n = 1, 2.7%). In the 24 patients switched from facial mask to total face mask because of refractory hypercapnia, encephalopathy score (3 3-4 vs. 2 2-3; p < 0.0001), PaCO2 (87 ± 25 mm Hg vs. 70 ± 17 mm Hg; p < 0.0001), and pH (7.24 ± 0.1 vs. 7.32 ± 0.09; p < 0.0001) significantly improved after 2 hrs of total face mask-delivered noninvasive ventilation. Patients switched early to total face mask (in the first 12 hrs) developed less pressure sores (n = 5, 24% vs. n = 13, 87%; p = 0.0002), despite greater length of noninvasive mechanical ventilation within the first 48 hrs (44 hrs vs. 34 hrs; p = 0.05) and less protective dressings (n = 2, 9.5% vs. n = 8, 53.3%; p = 0.007). The optimal cutoff value for face mask-delivered noninvasive mechanical ventilation duration in predicting facial pressure sores was 11 hrs (area under the receiver operating characteristic curve, 0.86 ± 0.04; 95% confidence interval 0.76-0.93; p < 0.0001; sensitivity, 84%; specificity, 71%).
In patients in hypercapnic acute respiratory failure, for whom escalation to intubation is deemed inappropriate, switching to total face mask can be proposed as a last resort therapy when face mask-delivered noninvasive mechanical ventilation has already failed to reverse acute respiratory failure. This strategy is particularly adapted to provide prolonged periods of continuous noninvasive mechanical ventilation while preventing facial pressure sores.
Targeted temperature management (TTM) currently is the only treatment with demonstrated efficacy in attenuating the harmful effects on the brain of ischemia-reperfusion injury after cardiac arrest. ...However, whether TTM is beneficial in the subset of patients with in-hospital cardiac arrest (IHCA) remains unclear.
Is TTM at 33 °C associated with better neurological outcomes after IHCA in a nonshockable rhythm compared with targeted normothermia (TN; 37 °C)?
We performed a post hoc analysis of data from the published Targeted Temperature Management for Cardiac Arrest with Nonshockable Rhythm randomized controlled trial in 584 patients. We included the 159 patients with IHCA; 73 were randomized to 33 °C treatment and 86 were randomized to 37 °C treatment. The primary outcome was survival with a good neurologic outcome (cerebral performance category CPC score of 1 or 2) on day 90. Mixed multivariate adjusted logistic regression analysis was performed to determine whether survival with CPC score of 1 or 2 on day 90 was associated with type of temperature management after adjustment on baseline characteristics not balanced by randomization.
Compared with TN for 48 h, hypothermia at 33 °C for 24 h was associated with a higher percentage of patients who were alive with good neurologic outcomes on day 90 (16.4% vs 5.8%; P = .03). Day 90 mortality was not significantly different between the two groups (68.5% vs 76.7%; P = .24). By mixed multivariate analysis adjusted by Cardiac Arrest Hospital Prognosis score and circulatory shock status, hypothermia was associated significantly with good day 90 neurologic outcomes (OR, 2.40 95% CI, 1.17-13.03; P = .03).
Hypothermia at 33 °C was associated with better day 90 neurologic outcomes after IHCA in a nonshockable rhythm compared with TN. However, the limited sample size resulted in wide CIs. Further studies of patients after cardiac arrest resulting from any cause, including IHCA, are needed.
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