A Patient-Level Meta-Analysis of Intensive Glucose Control in Critically Ill Adults.

BACKGROUND: Whether intensive glucose control reduces mortality in critically ill patients remains uncertain. Patient-level meta-analyses can provide more precise estimates of treatment effects than are currently available. METHODS: We pooled individual patient data from randomized trials investigating intensive glucose control in critically ill adults. The primary outcome was in-hospital mortality. Secondary outcomes included survival to 90 days and time to live cessation of treatment with vasopressors or inotropes, mechanical ventilation, and newly commenced renal replacement. Severe hypoglycemia was a safety outcome. RESULTS: Of 38 eligible trials (n=29,537 participants), 20 (n=14,171 participants) provided individual patient data including in-hospital mortality status for 7059 and 7049 participants allocated to intensive and conventional glucose control, respectively. Of these 1930 (27.3%) and 1891 (26.8%) individuals assigned to intensive and conventional control, respectively, died (risk ratio, 1.02; 95% confidence interval [CI], 0.96 to 1.07; P=0.52; moderate certainty). There was no apparent heterogeneity of treatment effect on in-hospital mortality in any examined subgroups. Intensive glucose control increased the risk of severe hypoglycemia (risk ratio, 3.38; 95% CI, 2.99 to 3.83; P<0.0001). CONCLUSIONS: Intensive glucose control was not associated with reduced mortality risk but increased the risk of severe hypoglycemia. We did not identify a subgroup of patients in whom intensive glucose control was beneficial. (Funded by the Australian National Health and Medical Research Council and others; PROSPERO number CRD42021278869.).

Association Between Selective Decontamination of the Digestive Tract and In-Hospital Mortality in Intensive Care Unit Patients Receiving Mechanical Ventilation: A Systematic Review and Meta-analysis.

Importance: The effectiveness of selective decontamination of the digestive tract (SDD) in critically ill adults receiving mechanical ventilation is uncertain. Objective: To determine whether SDD is associated with reduced risk of death in adults receiving mechanical ventilation in intensive care units (ICUs) compared with standard care. Data Sources: The primary search was conducted using MEDLINE, EMBASE, and CENTRAL databases until September 2022. Study Selection: Randomized clinical trials including adults receiving mechanical ventilation in the ICU comparing SDD vs standard care or placebo. Data Extraction and Synthesis: Data extraction and risk of bias assessments were performed in duplicate. The primary analysis was conducted using a bayesian framework. Main Outcomes and Measures: The primary outcome was hospital mortality. Subgroups included SDD with an intravenous agent compared with SDD without an intravenous agent. There were 8 secondary outcomes including the incidence of ventilator-associated pneumonia, ICU-acquired bacteremia, and the incidence of positive cultures of antimicrobial-resistant organisms. Results: There were 32 randomized clinical trials including 24 389 participants in the analysis. The median age of participants in the included studies was 54 years (IQR, 44-60), and the median proportion of female trial participants was 33% (IQR, 25%-38%). Data from 30 trials including 24 034 participants contributed to the primary outcome. The pooled estimated risk ratio (RR) for mortality for SDD compared with standard care was 0.91 (95% credible interval [CrI], 0.82-0.99; I2 = 33.9%; moderate certainty) with a 99.3% posterior probability that SDD reduced hospital mortality. The beneficial association of SDD was evident in trials with an intravenous agent (RR, 0.84 [95% CrI, 0.74-0.94]), but not in trials without an intravenous agent (RR, 1.01 [95% CrI, 0.91-1.11]) (P value for the interaction between subgroups = .02). SDD was associated with reduced risk of ventilator-associated pneumonia (RR, 0.44 [95% CrI, 0.36-0.54]) and ICU-acquired bacteremia (RR, 0.68 [95% CrI, 0.57-0.81]). Available data regarding the incidence of positive cultures of antimicrobial-resistant organisms were not amenable to pooling and were of very low certainty. Conclusions and Relevance: Among adults in the ICU treated with mechanical ventilation, the use of SDD compared with standard care or placebo was associated with lower hospital mortality. Evidence regarding the effect of SDD on antimicrobial resistance was of very low certainty.

Head CT for the intensivist: 10 tips and pearls.

Head imaging is an essential diagnostic tool for the management of patients with most acute neurological emergencies involving the brain. While numerous modalities including magnetic resonance imaging and catheter angiography play a role, computed tomography (CT) of the brain is far and away the most widely utilized technique because of its widespread availability and the fact that it is usually easier to implement in critically ill and potentially unstable patients. CT is particularly useful in identifying acute intracranial hemorrhage and this makes it often indispensable in the management of patients with traumatic brain injury and hemorrhagic stroke. However, shortcomings in identifying early ischemia on non-contrast CT mean that care must be taken in considering findings early after symptom onset, with newer CT sequences such as CT angiography and CT perfusion adding value. The critical role played by intensivists in managing neurocritical care patients necessitates familiarity and ability with viewing and understanding the advantages and shortcomings of head CT imaging and under which circumstances other modalities may be appropriate to obtain. This manuscript provides ten different circumstances commonly encountered in neurocritical care and how intensivists can use CT for the benefit of their patients.

Prospective, observational study of carbon dioxide gaps and free energy change and their association with fluid therapy following cardiac surgery.

Background Venoarterial carbon dioxide pressure (pv-a CO2 ) and content (Cv-a CO2 ) differences, including the ratio to arteriovenous oxygen content difference (Ca-v O2 ), and free energy changes (-∆∆Ga-v ) may reflect tissue hypoperfusion. The associations with changes in cardiac output (CO) or oxygen consumption (VO2 ) following fluid bolus administration were investigated. Methods Single-centre, observational study of 89 adult post-operative cardiac surgical patients admitted to ICU. The pv-a CO2 , Cv-a CO2 and their ratios to Ca-v O2 as well as the -∆∆Ga-v were determined before and after a 250-500 mL fluid bolus using arterial, central venous and mixed venous blood gas analyses. Responses associated with changes ≥ or <15% in CO or oxygen consumption (VO2 ) were compared. Results In 234 boluses, the mixed venous to arterial pv-a CO2 and its ratio to Ca-v O2 were independently associated with an increase in CO; odds ratio 1.3 (95% CI 1.1-1.5) and 1.7 (95% CI 1.5-1.9) respectively, P < .001) and VO2 ; odds ratio 2.1 (95% CI 1.3-3.1), P < .001 for Ca-v O2 . No measures of pv-a CO2 , Cv-a CO2 or related ratios to the Ca-v O2 were associated with an increase in CO ≥15% following a single volume bolus. The mixed venous and central venous Cv-a CO2 to Ca-v O2 ratios were different for the first bolus episode only; mean differences 0.81 (95% CI 0.13-1.5), P = .02 and 0.44 (95% CI 0.06-0.82), P = .02, respectively, for increased VO2  ≥ 15%. The -∆∆Ga-v did not change. Conclusion The venoarterial carbon dioxide gradients and related calculations to assess the adequacy of tissue perfusion before a fluid bolus were not associated with subsequent increases in CO of oxygen consumption. Editorial Comment In some shock conditions, regional tissue hypoperfusion can be obvious and arterio-venous differences for CO2 or O2 may reflect this. This is not always the case; sometimes there are A-V differences or even a high lactate level without any obvious regional tissue hypoperfusion. Fluid therapy is a cornerstone in shock resuscitation treatment, but determining optimal fluid therapy is challenging, particularly as fluid overload may be detrimental. Fluid challenges are used as an "ex juvantebus" method to dose fluid therapy, but it is not clear if a positive response reflects a state of hypoperfusion or the existence of a cardiac reserve. Still, a better understanding on how to target and guide fluid therapy is welcome, and studies digging into the problem are needed. Here, invasively monitored post-operative cardiac surgery patients are assessed as a model to investigate if carbon dioxide gaps and free energy charge may be useful in detecting possible tissue hypoperfusion.

Microvascular reactivity, assessed by near-infrared spectroscopy and a vascular occlusion test, is associated with patient outcomes following cardiac surgery: A prospective observational study.

BACKGROUND: Microvascular dysfunction in patients admitted to the ICU following cardiac surgery may be related to perioperative complications and increased resource utilisation even in the presence of acceptable systemic haemodynamic variables. OBJECTIVES: To assess the relationship between microvascular impairment using peripheral near-infrared spectroscopy at ICU admission and 6 h postadmission and the duration of mechanical ventilatory support, length of stay in ICU and in hospital. DESIGN: Prospective, observational cohort study. SETTING: Single-centre, tertiary-level cardiac ICU. PATIENTS: Sixty-nine adult patients following elective cardiac surgery excluding patients with on-going extracorporeal support or in whom tissue haemoglobin oxygen saturation (StO2) measurements were not feasible. MAIN OUTCOME MEASURES: Thenar and forearm StO2 in response to a vascular occlusion test to calculate desaturation and reperfusion slopes. A logistic regression model was used to ascertain the associations between StO2, desaturation and reperfusion slopes as well as cardiac index, mean arterial pressure, arterial lactate concentrations and prolonged (≥75th percentile) duration of mechanical ventilation, ICU length of stay and hospital length of stay. RESULTS: A reduced reperfusion slope at ICU admission was associated independently with prolonged mechanical ventilation at thenar (OR 0.08; 95% CI [0.02 to 0.47], P = 0.003) and forearm [OR 0.2 (0.04 to 0.59), P = 0.006] sites. Similarly, a reduced Rres was associated with prolonged ICU LOS at both thenar [OR 0.3 (0.13 to 0.77), P = 0.007] and forearm [OR 0.2 (0.05 to 0.62), P = 0.007] sites at ICU0 h, as well as ICU6 h [OR 0.2 (0.05 to 0.66), P = 0.004 and OR 0.05 (0.008 to 0.34), P = 0.002]. An increased Rdes was associated with prolonged hospital LOS at the thenar eminence at ICU0 h [OR 1.9 (1.4 to 2.3), P = 0.004] and ICU6 h [OR 6.7 (2.0 to 23), P = 0.002] as well as the forearm at ICU0 h [OR 1.5 (1.3 to 1.9), P = 0.004] and ICU6 h [OR 1.6 (1.3 to 2.1), P = 0.004]. CONCLUSION: In the early postoperative period following cardiac surgery, changes in thenar and forearm tissue oxygenation variables are associated with patient resource utilisation outcomes.

Fluid Responsiveness After CArdiac Surgery (FRACAS): A Prospective Observational Study Using Peripheral Near-Infrared Spectroscopy.

OBJECTIVES: To describe tissue oxygen saturation (StO2) in response to a vascular occlusion test using thenar eminence and forearm near-infrared spectroscopy (NIRS) and the association with volume responsiveness after cardiac surgery. DESIGN: Single-center, prospective, observational cohort study. SETTING: Cardiothoracic intensive care unit. PARTICIPANTS: Seventy-six post-cardiac surgical adults. INTERVENTIONS: Immediately before and 10 minutes after a 250-to-500 mL fluid bolus, StO2 was measured in response to a vascular occlusion test to calculate tissue deoxygenation (Rdes) and reoxygenation (Rres) rates. Concurrently, systemic hemodynamic, metabolic, and blood gas variables were collected. MEASUREMENTS AND MAIN RESULTS: A total of 203 boluses were captured using thenar NIRS and 141 boluses using forearm NIRS. Approximately 25% of boluses increased cardiac output by ≥15% (volume responders). Thenar and forearm Rdes decreased in responders, but increased (thenar) or remained unchanged (forearm) in nonresponders. A logistic regression model of the association among StO2, Rdes and Rres, and volume responsiveness was significant for thenar measurements (p = 0.001) with an area under the receiver operating characteristic of 0.69 (95% confidence interval: 0.62-0.75). It also was significant (p = 0.02) for forearm measurements, with an area under the receiver operating characteristic of 0.71 (0.62-0.79). Rdes was an independent variable in both instances (odds ratio 0.31 [0.14-0.69], thenar; odds ratio 0.60 [0.45-0.80], forearm). Thenar and forearm NIRS variables were correlated poorly with cardiac output, stroke volume, systemic oxygen delivery and consumption index, mixed venous, and central venous oxygen saturation (Spearman׳s coefficients, r = 0.17-0.46, p < 0.002). CONCLUSION: In post-cardiac surgical patients, thenar and forearm NIRS variables were associated with volume responsiveness although not achieving precision necessary for clinical management.