Fluids in Sepsis and Septic Shock (FISSH): protocol for a pilot randomised controlled trial

RESPIRATORY VARIABILITY OF VALVULAR PEAK SYSTOLIC VELOCITY AS A NEW INDICATOR OF FLUID RESPONSIVENESS IN PATIENTS WITH SEPTIC SHOCK

ABSTRACT

Objective: The aim of this study was to evaluate the reliability and feasibility of pulse Doppler measurements of peak velocity respiratory variability of mitral and tricuspid valve rings during systole as new dynamic indicators of fluid responsiveness in patients with septic shock. Methods: Transthoracic echocardiography (TTE) was performed to measure the respiratory variability of aortic velocity-time integral (∆VTI), respiratory variability of tricuspid annulus systolic peak velocity (∆RVS), respiratory variability of mitral annulus systolic peak velocity (∆LVS), and other related indicators. Fluid responsiveness was defined as a 10% increase in cardiac output after fluid expansion, assessed by TTE. Results: A total of 33 patients with septic shock were enrolled in this study. First, there was no significant difference in the population characteristics between the fluid responsiveness positive group (n = 17) and the fluid responsiveness negative group (n = 16) ( P > 0.05). Second, Pearson correlation test showed that ∆RVS, ∆LVS, and TAPSE with the relative increase in cardiac output after fluid expansion ( R = 0.55, P = 0.001; R = 0.40, P = 0.02; R = 0.36, P = 0.041). Third, multiple logistic regression analysis demonstrated that ∆RVS, ∆LVS, and TAPSE were significantly correlated with fluid responsiveness in patients with septic shock. Fourth, receiver operating characteristic (ROC) curve analysis revealed that ∆VTI, ∆LVS, ∆RVS, and TAPSE had good predictive ability for fluid responsiveness in patients with septic shock. The area under the curve (AUC) of ∆VTI, ∆LVS, ∆RVS, and TAPSE for predicting fluid responsiveness was 0.952, 0.802, 0.822, and 0.713, respectively. The sensitivity (Se) values were 1.00, 0.73, 0.81, and 0.83, whereas the specificity (Sp) values were 0.84, 0.91, 0.76, and 0.67, respectively. The optimal thresholds were 0.128, 0.129, 0.130, and 13.9 mm, respectively. Conclusion: Tissue Doppler ultrasound evaluation of respiratory variability of mitral and tricuspid annular peak systolic velocity could be a feasible and reliable method for the simple assessment of fluid responsiveness in patients with septic shock.

Adjunctive ketamine for sedation in critically ill mechanically ventilated patients: an active-controlled, pilot, feasibility clinical trial

OBJECTIVE

Ketamine has been shown to decrease sedative requirements in intensive care unit (ICU). Randomized trials are limited on patient-centered outcomes. We designed this pilot trial to evaluate the feasibility of a large randomized controlled trial (RCT) testing the effect of ketamine as an adjunct analgosedative compared with standard of care alone as a control group (CG) in critically ill patients with mechanical ventilation (MV). We also provided preliminary evidence on clinically relevant outcomes to plan a larger trial.

MATERIAL AND METHODS

Pilot, active-controlled, open-label RCT was conducted at medical, surgical, and transplant ICUs at a large tertiary and quaternary care medical institution (King Faisal Specialist Hospital and Research Center, Saudi Arabia). The study included adult patients who were intubated within 24 h, expected to require MV for the next calendar day, and had institutional pain and sedation protocol initiated. Patients were randomized in a 1:1 ratio to adjunct ketamine infusion 1-2 μg/kg/min for 48 h or CG alone.

RESULTS

Of 437 patients screened from September 2019 through November 2020, 83 (18.9%) patients were included (43 in CG and 40 in ketamine) and 352 (80.5%) were excluded. Average enrollment rate was 3-4 patients/month. Consent and protocol adherence rates were adequate (89.24% and 76%, respectively). Demographics were balanced between groups. Median MV duration was 7 (interquartile range [IQR] 3-9.25 days) in ketamine and 5 (IQR 2-8 days) in CG. Median VFDs was 19 (IQR 0-24.75 days) in ketamine and 19 (IQR 0-24 days) in the CG (p = 0.70). More patients attained goal Richmond Agitation-Sedation Scale at 24 and 48 h in ketamine (67.5% and 73.5%, respectively) compared with CG (52.4% and 66.7%, respectively). Sedatives and vasopressors cumulative use, and hemodynamic changes were similar. ICU length-of-stay was 12.5 (IQR 6-21.2 days) in ketamine, compared with 12 (IQR 5.5-23 days) in CG. No serious adverse events were observed in either group.

CONCLUSIONS

Ketamine as an adjunct analgosedative agent appeared to be feasible and safe with no negative impact on outcomes, including hemodynamics. This pilot RCT identified areas of improvement in study protocol before conducting a large, adequately powered, multicenter RCT which is likely justified to investigate ketamine association with patient-centered outcomes further. Trial registration ClinicalTrials.gov: NCT04075006. Registered on 30 August 2019. Current controlled trials: ISRCTN14730035. Registered on 3 February 2020.

Resuscitation Fluids in Septic Shock: A Network Meta-Analysis of Randomized Controlled Trials

The aim of this study was to assess the efficacy and safety of various resuscitation fluids in septic shock by adopting a network meta-analysis (NMA). Randomized controlled trials (RCTs) comparing resuscitation fluids in septic shock were carried out by retrieving electronic databases. NMAs of 28-day mortality, 90-day mortality, incidence of acute kidney injury (AKI), and the need for renal replacement therapy (RRT) were conducted using the STATA 15.0 software. Probability-based ranking and surface under cumulative ranking (SUCRA) were performed to identify the optimal resuscitation fluid. Inconsistencies were evaluated by node-splitting analysis and a loop-specific approach. Furthermore, publication bias was analyzed by funnel plots. A total of 13 RCTs were enrolled in the analysis. The NMA results revealed that no significant differences were detected in the outcomes of 28-day mortality and 90-day mortality among various resuscitation fluids. The SUCRAs (the first indicates the best) of 28-day mortality showed that the hypertonic sodium chloride/hydroxyethyl starch 40 solution ranked the highest (93.8%), followed by the balanced solution (BS) (69.6%), and albumin (61.9%). On the other hand, the SUCRAs of 90-day mortality revealed that gelatin (GEL) ranked the highest (75.1%), followed by BS (55.1%), and NS (52.4%). The NMA results of AKI demonstrated that high-molecular-weight hydroxyethyl starch (H-HES) was associated with increased risk of AKI in comparison with GEL, BS, and L-HES. The SUCRAs of AKI showed that GEL ranked the highest (74.4%), followed by NS (64.9%), and BS (58.3%). In addition, the NMA results of RRT revealed that H-HES was associated with an increased need for RRT in comparison with BS and NS, and L-HES was associated with increased need of RRT in comparison with BS. The SUCRAs of RRT revealed that NS ranked the highest (91.6%), followed by BS (74.4%) and L-HES (36.1%). No significant inconsistencies were shown by the node-splitting analysis and no publication bias was demonstrated in the funnel plots. In conclusion, BS was determined as the preferred resuscitation fluid for septic shock. Moreover, the use of GEL requires further evaluation. H-HES was associated with a significant risk of AKI and RRT, whereas L-HES with an increased need for RRT compared with BS. Thus, both resuscitation fluids should be avoided for septic shock.

Carotid Ultrasound in Assessing Fluid Responsiveness in Patients with Hypotension and Suspected Sepsis

PURPOSE

We sought to assess whether ultrasound (US) measurements of carotid flow time (CFTc) and carotid blood flow (CBF) predict fluid responsiveness in patients with suspected sepsis.

METHODS

This was a prospective observational study of hypotensive (systolic blood pressure < 90) patients "at risk" for sepsis receiving intravenous fluids (IVF) in the emergency department. US measurements of CFTc and CBF were performed at time zero and upon completion of IVF. All US measurements were repeated after a passive leg raise (PLR) maneuver. Fluid responsiveness was defined as normalization of blood pressure without persistent hypotension or need for vasopressors.

RESULTS

A convenience sample of 69 patients was enrolled. The mean age was 65; 49% were female. Fluid responders comprised 52% of the cohort. CFTc values increased significantly with both PLR (P = 0.047) and IVF administration (P = 0.003), but CBF values did not (P = 0.924 and P = 0.064 respectively). Neither absolute CFTc or CBF measures, nor changes in these values with PLR or IVF bolus, predicted fluid responsiveness, mortality, or the need for intensive care unit admission.

CONCLUSION

In patients with suspected sepsis, a fluid challenge resulted in a significant change in CFTc, but not CBF. Neither absolute measurement nor delta measurements with fluid challenge predicted clinical outcomes.

Chloride and Other Electrolyte Concentrations in Commonly Available 5% Albumin Products

OBJECTIVE

Use of hyperchloremic IV fluids for resuscitation in sepsis may be associated with increased mortality and use of renal replacement therapy. After crystalloids, 5% human albumin represents the second most common resuscitation fluid in the ICU. Its chloride concentration is rarely considered in the clinical setting. This study quantifies previously undocumented chloride concentrations of three 5% albumin solutions using biochemical analysis.

DESIGN

We performed blinded analysis of the electrolyte concentration of albumin samples obtained directly from the national blood supplier (Canadian Blood Services). Two-tailed independent t tests were performed for all possible comparative analyses. Analysis of variance testing was performed for relevant three-way comparisons. Significance threshold was set at p less than 0.05.

SETTING

All samples were analyzed in the core laboratory at an academic hospital associated with McMaster University in Hamilton, Ontario, Canada.

SUBJECTS

We analyzed 65 albumin samples from three available brands obtained through Canadian Blood Services. They include Plasbumin (n = 21), Alburex (n = 24), Octalbin (n = 20).

INTERVENTION

Laboratory technologists blinded to product identification measured the concentration of electrolytes, extended electrolytes, lactate, and albumin of each sample using the Abbott ARCHITECT c8000 chemistry analyzer.

MEASUREMENTS AND MAIN RESULTS

The mean chloride concentration of Plasbumin, Alburex, and Octalbin, respectively, were 109.4 mmol/L (SD, 1.3), 123.6 mmol/L (SD, 1.3), and 136.8 mmol/L (SD, 0.4). The mean sodium concentration of Plasbumin, Alburex, and Octalbin, respectively, were 139.6 mmol/L (SD, 1.6), 137.3 mmol/L (SD, 2.2), and 149.4 mmol/L (SD, 0.5). The chloride and sodium concentration differed significantly for all two-way comparisons (p < 0.0001) and multiple comparison testing (p < 0.0001).

CONCLUSION

This study is the first to identify and document a statistically significant variability in the chloride concentration of available 5% albumin products. This study has also informed a pilot randomized controlled trial examining the effect of administering high chloride versus low chloride fluids in critically ill patients with sepsis.

Impact of Point-of-Care Ultrasound in the Emergency Department on Care Processes and Outcomes in Critically Ill Nontraumatic Patients

Supplemental Digital Content is available in the text.

Outcomes data on point-of-care ultrasound (POCUS) in critically ill patients are lacking. This study examines the association between POCUS in the emergency department and outcomes in critically ill patients.

"I don't get no respect": the role of chloride in acute kidney injury

Acute kidney injury (AKI) is a major public health problem that complicates 10-40% of hospital admissions. Importantly, AKI is independently associated with increased risk of progression to chronic kidney disease, end-stage renal disease, cardiovascular events, and increased risk of in-hospital and long-term mortality. The chloride content of intravenous fluid has garnered much attention over the last decade, as well as its association with excess use and adverse outcomes, including AKI. Numerous studies show that changes in serum chloride concentration, independent of serum sodium and bicarbonate, are associated with increased risk of AKI, morbidity, and mortality. This comprehensive review details the complex renal physiology regarding the role of chloride in regulating renal blood flow, glomerular filtration rate, tubuloglomerular feedback, and tubular injury, as well as the findings of clinical research related to the chloride content of intravenous fluids, changes in serum chloride concentration, and AKI. Chloride is underappreciated in both physiology and pathophysiology. Although the exact mechanism is debated, avoidance of excessive chloride administration is a reasonable treatment option for all patients and especially in those at risk for AKI. Therefore, high-risk patients and those with "incipient" AKI should receive balanced solutions rather than normal saline to minimize the risk of AKI.

Association Between Early Intravenous Fluids Provided by Paramedics and Subsequent In-Hospital Mortality Among Patients With Sepsis

IMPORTANCE

Early administration of intravenous fluids is recommended for all patients with sepsis, but the association of this treatment with mortality may depend on the patient's initial blood pressure.

OBJECTIVE

To test the association between early administration of intravenous fluids by paramedics and in-hospital mortality among patients with sepsis, accounting for patients' initial blood pressure.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study in which multiple analyses were conducted using a 1-year (from April 1, 2015, to March 31, 2016) cohort of 1871 patients with sepsis who were transported to the hospital by paramedics from a large emergency medical services system in Alberta, Canada. Multivariable logistic regression and a propensity-matched analysis adjusting for baseline patient characteristics were used to minimize confounding by indication and test the association between early administration of intravenous fluids by paramedics and in-hospital mortality. Nonparametric additive regression was used to assess the association of early administration of intravenous fluids with prehospital and in-hospital treatment times.

EXPOSURES

Intravenous fluids administered by paramedics at the point of first contact and during transportation to the hospital.

MAIN OUTCOMES AND MEASURES

The primary outcome was in-hospital mortality. Secondary outcomes included prehospital and emergency department treatment times.

RESULTS

A total of 1871 patients with sepsis were identified (955 women and 916 men; median age, 77 years [interquartile range, 64-85 years]), with an overall in-hospital mortality of 28.2% (n = 528). More than half of patients (1015 [54.2%]) received intravenous fluids from paramedics; the median volume provided was 400 mL (interquartile range, 250-500 mL). The association of intravenous fluids with mortality depended on the patient's initial systolic blood pressure (range, 42-222 mm Hg; P < .001 for interaction). For example, in a typical patient with an initial systolic blood pressure of 100 mm Hg, intravenous fluids were associated with decreased mortality (odds ratio, 0.73; 95% CI, 0.56-0.95), but for a typical patient with the median initial systolic blood pressure of 125 mm Hg, intravenous fluids were not associated with in-hospital mortality (odds ratio, 1.41; 95% CI, 0.81-2.44). Similar results were obtained in the propensity-matched analysis. The administration of intravenous fluids was associated with increased prehospital time compared with patients who did not receive intravenous fluids (median difference, 3.2 minutes; 95% CI, 1.7-4.7 minutes) but was not associated with time to assessment in the emergency department (median difference, 2.4 minutes; 95% CI, -2.4 to 7.3 minutes).

CONCLUSIONS AND RELEVANCE

Intravenous fluids provided by paramedics were associated with reduced in-hospital mortality for patients with sepsis and hypotension but not for those with a higher initial systolic blood pressure.

Expert statement for the management of hypovolemia in sepsis

Hypovolemia is frequent in patients with sepsis and may contribute to worse outcome. The management of these patients is impeded by the low quality of the evidence for many of the specific components of the care. In this paper, we discuss recent advances and controversies in this field and give expert statements for the management of hypovolemia in patients with sepsis including triggers and targets for fluid therapy and volumes and types of fluid to be given. Finally, we point to unanswered questions and suggest a roadmap for future research.

Hyperchloraemia in sepsis

Chloride represents—quantitatively—the most prevalent, negatively charged, strong plasma electrolyte. Control of chloride concentration is a probable major mechanism for regulating the body’s acid–base balance and for maintaining homeostasis of the entire internal environment. The difference between the concentrations of chloride and sodium constitutes the major contributor to the strong ion difference (SID); SID is the key pH regulator in the body, according to the physicochemical approach. Hyperchloraemia resulting from either underlying diseases or medical interventions is common in intensive care units. Recent studies have demonstrated the importance of hyperchloraemia in metabolic acidosis and in other pathophysiological disorders present in sepsis. The aim of this narrative review is to present the current knowledge about the effects of hyperchloraemia, in relation to the underlying pathophysiology, in septic patients.