Influence of systemic hemodynamics on microcirculation during sepsis

Association between diastolic blood pressure during the first 24 h and 28-day mortality in patients with septic shock: a retrospective observational study

BACKGROUND

Although the mean arterial pressure (MAP) target of 65 mmHg was achieved, diastolic blood pressure (DBP) was still low in some septic shock patients. The effects of DBP on the prognosis and optimal target for patients with septic shock are unclear. We sought to investigate the relationship between DBP and 28-day mortality in septic shock patients.

METHODS

In this retrospective observational study, we obtained data from the Chinese Database in Intensive Care (CDIC). We included patients with an admission diagnosis of septic shock and shock was controlled. DBP was measured every 1 h, and the mean DBP during the first 24 h (mDBP24h) was recorded. The primary outcome was 28-day mortality. Multivariable logistic regression determined the relationship between mDBP24h and 28-day mortality.

RESULTS

In total, 1251 patients were finally included. The 28-day mortality of included septic shock patients was 28.3%. The mDBP24h, not mSBP24h, was higher among 28-day survivors compared with non-survivors. 28-day mortality was inversely associated with mDBP24h (unadjusted OR 0.814 per 10 mmHg higher mDBP24h, P = 0.003), with a stepwise increase in 28-day mortality at lower mDBP24h. The 28-day mortality of patients with mDBP24h < 59 mmHg had an absolute risk reduction of 9.4% (P = 0.001). And mDBP24h < 59 mmHg was the remaining high risk factor inversely associated with 28-day mortality after multivariable adjustment (adjusted OR 1.915, 95% CI 1.037-3.536, P = 0.038), while mMAP24h and mSBP24h were not.

CONCLUSION

In patients with septic shock after initial resuscitation, we observed an inverse association between mDBP24h and 28-day mortality. The poor outcomes in patients with mDBP24h < 59 mmHg provide indirect evidence supporting a further DBP goal of 59 mmHg for patients with septic shock after MAP of 65 mmHg was achieved.

The association of diastolic arterial pressure and heart rate with mortality in septic shock: a retrospective cohort study

BACKGROUND

The effects of diastolic arterial pressure (DAP) and heart rate (HR) on the prognosis of patients with septic shock are unclear, and whether these effects persist over time is unknown. We aimed to investigate the relationship between exposure to different intensities of DAP and HR over time and mortality at 28 days in patients with septic shock.

METHODS

In this cohort study, we obtained data from the Medical Information Mart for Intensive Care IV, which includes the data of adult patients (≥ 18 years) with septic shock who underwent invasive blood pressure monitoring. We excluded patients who received extracorporeal membrane oxygenation (ECMO) or glucocorticoids within 48 h of ICU admission. The primary outcome was mortality at 28 days. Piece-wise exponential additive mixed models were used to estimate the strength of the associations over time.

RESULTS

In total, 4959 patients were finally included. The median length of stay in the ICU was 3.2 days (IQR: 1.5-7.1 days), and the mortality in the ICU was 12.9%, with a total mortality at 28 days of 15.9%. After adjustment for baseline and time-dependent confounders, both daily time-weighted average (TWA) DAP and HR were associated with increased mortality at 28 days and strong association, mainly in the early to mid-stages of the disease. The results showed that mortality in patients with septic shock was lowest at a DAP of 50-70 mm Hg and an HR of 60-90 beats per minute (bpm). Throughout, a significant increase in the risk of death was found with daily exposure to TWA-DAP ≤ 40 mmHg (hazard ratio 0.99, 95% confidence interval (CI) 0.94-1.03) or TWA-HR ≥ 100 bpm (hazard ratio 1.16, 95% CI 1.1-1.21). Cumulative and interactive effects of harmful exposure (TWA-DAP ≤ 40 mmHg and TWA-HR ≥ 100 bpm) were also observed.

CONCLUSION

The optimal ranges for DAP and HR in patients with septic shock are 50-70 mmHg and 60-90 bpm, respectively. The cumulative and interactive effects of exposure to low DAP (≤ 40 mmHg) and tachycardia (≥ 100 bpm) were associated with an increased risk of death.

Can central-venous oxygen saturation be estimated from tissue oxygen saturation during a venous occlusion test?

OBJECTIVE

To test whether tissue oxygen saturation (StO2) after a venous occlusion test estimates central venous oxygen saturation (ScvO2).

METHODS

Observational study in intensive care unit patients. Tissue oxygen saturation was monitored (InSpectra Tissue Spectrometer Model 650, Hutchinson Technology Inc., MN, USA) with a multiprobe (15/25mm) in the thenar position. A venous occlusion test in volunteers was applied in the upper arm to test the tolerability and pattern of StO2 changes during the venous occlusion test. A sphygmomanometer cuff was inflated to a pressure 30mmHg above diastolic pressure until StO2 reached a plateau and deflated to 0mmHg. Tissue oxygen saturation parameters were divided into resting StO2 (r-StO2) and minimal StO2 (m-StO2) at the end of the venous occlusion test. In patients, the cuff was inflated to a pressure 30mmHg above diastolic pressure for 5 min (volunteers' time derived) or until a StO2 plateau was reached. Tissue oxygen saturation parameters were divided into r-StO2, m-StO2, and the mean time that StO2 reached ScvO2. The StO2 value at the mean time was compared to ScvO2.

RESULTS

All 9 volunteers tolerated the venous occlusion test. The time for tolerability or the StO2 plateau was 7 ± 1 minutes. We studied 22 patients. The mean time for StO2 equalized ScvO2 was 100 sec and 95 sec (15/25mm probes). The StO2 value at 100 sec ([100-StO2] 15mm: 74 ± 7%; 25mm: 74 ± 6%) was then compared with ScvO2 (75 ± 6%). The StO2 value at 100 sec correlated with ScvO2 (15 mm: R2 = 0.63, 25mm: R2 = 0.67, p < 0.01) without discrepancy (Bland Altman).

CONCLUSION

Central venous oxygen saturation can be estimated from StO2 during a venous occlusion test.

Cox-LASSO Analysis for Hospital Mortality in Patients With Sepsis Received Continuous Renal Replacement Therapy: A MIMIC-III Database Study

Background

Sepsis remains the leading cause of mortality in-hospital in the intensive care unit (ICU). Continuous renal replacement therapy (CRRT) is recommended as an adjuvant therapy for hemodynamics management in patients with sepsis. The aim of this study was to develop an adaptive least absolute shrinkage and selection operator (LASSO) for the Cox regression model to predict the hospital mortality in patients with Sepsis-3.0 undergoing CRRT using Medical Information Martin Intensive Care (MIMIC)-III v1.4.

Methods

Patients who met the Sepsis-3.0 definition were identified using the MIMIC-III v1.4. Among them, patients who received CRRT during ICU hospitalization were included in this study. According to the survival status, patients were split into death or survival group. Adaptive LASSO for the Cox regression model was constructed by STATA software. At last, nomogram and Kaplan-Meier curves were drawn to validate the model.

Results

A total of 181 patients who met Sepsis 3.0 criteria received CRRT were included in the study, in which, there were 31 deaths and 150 survivals during hospitalization, respectively. The overall in-hospital mortality was 17.1%. According to the results of multivariate Cox-LASSO regression analysis, use of vasopressor, international normalized ratio (INR) ≥1.5, and quick sequential organ failure assessment (qSOFA) score were associated with hospital mortality in patients with sepsis who underwent CRRT, but lactate level, mechanical ventilation (MV) support, PaO₂/FiO₂, platelet count, and indicators of acute kidney injury (AKI), such as blood urea nitrogen (BUN) and creatinine, were not independently associated with hospital mortality after adjusted by qSOFA. The risk nomogram and Kaplan-Meier curves verified that the use of vasopressor and INR ≥1.5 possess significant predictive value.

Conclusions

Using the Cox-LASSO regression model, use of vasopressor, INR ≥1.5, and qSOFA score are found to be associated with hospital mortality in patients with Sepsis-3.0 who received CRRT. This finding may assist clinicians in tailoring precise management and therapy for these patients who underwent CRRT.

Associations between peripheral perfusion disorders, mean arterial pressure and dose of norepinephrine administrated in the early phase of septic shock

The aim of the study was to explore the correlations between peripheral perfusion, mean arterial pressure and the dose-rate of norepinephrine (NE) infused for the treatment of septic shock. The study is retrospective analysis of data acquired prospectively on 57 patients during the first 24 hours after the occurrence of the shock. Clinical and haemodynamic characteristics, skin perfusion parameters (capillary refill time [CRT], mottling score and temperature gradients) and the dose rate of NE infusion were collected. Negative correlations between mean arterial pressure (MAP) and temperature gradients (core-to-toe: P = .03, core-to-index: P = .04) were found and abnormal CRT was associated with lower MAP (P = .02). The dose rate of NE was negatively correlated with temperature gradients (core-to-toe: P = .02, core-to-index: P = .01, forearm-to-index: P = .008) in the overall population. In patients receiving NE for at least 12 hours, the NE dose rate positively was correlated with the mottling score (P = .006), temperature gradients (core-to-toe: P = .04, forearm-to-index: P = .02, core-to-index: P = .005) and CRT (P = .001). The dose of NE administrated was associated with 14-days mortality (odds ration [OR] = 1.21 [1.06-1.38], P = .006) and with 28-days mortality (OR = 1.17 [1.01-1.36], P = 0.04). In conclusion, the study described the presence of correlations between peripheral perfusion and MAP and between peripheral perfusion and the dose rate of NE infusion.