Diagnostic Accuracy of Vascular Ultrasonography for Postanesthesia Induction Hypotension: A Systematic Review and Network Meta-Analysis.

BACKGROUND: Arterial hypotension commonly occurs after anesthesia induction and is associated with negative clinical outcomes. Point-of-care ultrasound examination has emerged as a modality to predict postinduction hypotension (PIH). We performed a systematic review and network meta-analysis of the predictive performance of point-of-care ultrasound tests for PIH in noncardiac, nonobstetrical routine adult surgery. METHODS: Online databases were searched for diagnostic test accuracy studies of point-of-care ultrasound for predicting PIH up to March 30, 2023. The systematic review followed the Cochrane methodology. A Bayesian diagnostic test accuracy network meta-analysis model was used, with PIH as defined by study authors as the main outcome. Risk of bias and applicability were examined through the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) score. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to assess evidence certainty. RESULTS: A total of 32 studies with 2631 participants were eligible for systematic review. Twenty-six studies with 2258 participants representing 8 ultrasound tests were included in the meta-analysis. Inferior vena cava collapsibility index (22 studies) sensitivity was 60% (95% credible interval [CrI], 49%-72%) and specificity was 83% (CrI, 74%-89%). Carotid artery corrected flow time (2 studies) sensitivity was 91% (CrI, 76%-98%) and specificity was 90% (CrI, 59%-98%). There were serious bias and applicability concerns due to selection bias and inappropriate blinding. The certainty of evidence was very low for all tests. CONCLUSIONS: The predictive performance of point-of-care ultrasound for PIH is uncertain. There is a need for high-quality randomized controlled trials with appropriate blinding and void of selection bias.

The Effect of CytoSorb on Inflammatory Markers in Critically Ill Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: The effectiveness of CytoSorb at removing inflammatory mediators in critically ill patients is controversial. DATA SOURCES: Electronic databases were searched from inception to May 2023. STUDY SELECTION: Randomized controlled trials reporting the effects of CytoSorb therapy on inflammatory parameters in critically ill patients with hyperinflammatory conditions were included. DATA EXTRACTION: Two authors screened articles for eligibility, extracted data, and assessed the risk of bias, conflicts of interest, and certainty of evidence (CoE). The primary outcome was interleukin (IL)-6 at 1 day after initiation of the therapy. Secondary outcomes included various inflammatory markers at 1, 2, 3, and 5 days and mortality. Data were pooled if at least three trials reported the outcome of interest. We conducted meta-analyses of the data using a random-effects model. DATA SYNTHESIS: Seventeen trials ( n = 855) were included. Fourteen trials were judged to have notable concern about conflicts of interest. Seven trials were performed in medical ICU patients with hyperinflammatory conditions and 10 in complex cardiovascular surgery under cardiopulmonary bypass. Hemoadsorption with CytoSorb was not associated with lower IL-6 at 1 day (mean difference -5.98 [95% CI, -30.44 to 18.48] pg/mL), 2 days, 3 days, or 5 days after initiation of the treatment, as well as the concentration of procalcitionin. The levels of C-reactive protein were not lower with CytoSorb at 1, 2, and 3 days. The use of CytoSorb was associated with higher mortality at latest follow-up (relative risk = 1.22 [95% CI, 1.02-1.45]) and at 30 days. CoE ranged from low to very low. CONCLUSIONS: The use of CytoSorb hemoadsorption in a mixed population of critically ill patients with hyperinflammatory conditions does not exhibit a consistent decrease in IL-6 and other inflammatory parameters within the first 5 days of treatment. The significant uncertainty surrounding these findings highlights the need for further investigations.

Impact of pharmacological interventions on intrapulmonary shunt during one-lung ventilation in adult thoracic surgery: a systematic review and component network meta-analysis.

BACKGROUND: Intrapulmonary shunt is a major determinant of oxygenation in thoracic surgery under one-lung ventilation. We reviewed the effects of available treatments on shunt, Pao2/FiO2 and haemodynamics through systematic review and network meta-analysis. METHODS: Online databases were searched for RCTs comparing pharmacological interventions and intrapulmonary shunt in thoracic surgery under one-lung ventilation up to March 30, 2022. Random-effects (component) network meta-analysis compared 24 treatments and 19 treatment components. The Confidence in Network Meta-Analysis (CINeMA) framework assessed evidence certainty. The primary outcome was intrapulmonary shunt fraction during one-lung ventilation. RESULTS: A total of 55 RCTs were eligible for systematic review (2788 participants). The addition of N2O (mean difference [MD]=-15%; 95% confidence interval [CI], -25 to -5; P=0.003) or almitrine (MD=-13%; 95% CI, -20 to -6; P<0.001) to propofol anaesthesia were efficient at decreasing shunt. Combined epidural anaesthesia (MD=3%; 95% CI, 1-5; P=0.005), sevoflurane (MD=5%; 95% CI, 2-8; P<0.001), isoflurane (MD=6%; 95% CI, 4-9; P<0.001), and desflurane (MD=9%; 95% CI, 4-14; P=0.001) increased shunt vs propofol. Almitrine (MD=147 mm Hg; 95% CI, 58-236; P=0.001), dopexamine (MD=88 mm Hg; 95% CI, 4-171; P=0.039), and iloprost (MD=81 mm Hg; 95% CI, 4-158; P=0.038) improved Pao2/FiO2. Certainty of evidence ranged from very low to moderate. CONCLUSIONS: Adding N2O or almitrine to propofol anaesthesia reduced intrapulmonary shunt during one-lung ventilation. Halogenated anaesthetics increased shunt in comparison with propofol. The effects of N2O, iloprost, and dexmedetomidine should be investigated in future research. N2O results constitute a research hypothesis currently not backed by any direct evidence. The clinical availability of almitrine is limited. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42022310313.

The importance of liver function assessment before cardiac surgery: A narrative review.

The demand for cardiac surgery procedures is increasing globally. Thanks to an improvement in survival driven by medical advances, patients with liver disease undergo cardiac surgery more often. Liver disease is associated with the development of heart failure, especially in patients with advanced cirrhosis. Cardiovascular risk factors can also contribute to the development of both cardiomyopathy and liver disease and heart failure itself can worsen liver function. Despite the risk that liver disease and cirrhosis represent for the perioperative management of patients who undergo cardiac surgery, liver function is often not included in common risk scores for preoperative evaluation. These patients have worse short and long-term survival when compared with other cardiac surgery populations. Preoperative evaluation of liver function, postoperative management and close postoperative follow-up are crucial for avoiding complications and improving results. In the present narrative review, we discuss the pathophysiological components related with postoperative complications and mortality in patients with liver disease who undergo cardiac surgery and provide recommendations for the perioperative management.

Cardioprotective Effects of Glucose-Insulin-Potassium Infusion in Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-Analysis.

The infusion of glucose-insulin-potassium (GIK) has yielded conflicting results in terms of cardioprotective effects. We conducted a meta-analysis to examine the impact of perioperative GIK infusion in early outcome after cardiac surgery. Randomized controlled trials (RCTs) were eligible if they examined the efficacy of GIK infusion in adults undergoing cardiac surgery. The main study endpoint was postoperative myocardial infarction (MI) and secondary outcomes were hemodynamics, any complications and hospital resources utilization. Subgroup analyses explored the impact of the type of surgery, GIK composition and timing of administration. Odds ratio (OR) or mean difference (MD) with 95% confidence interval (CI) were calculated with a random-effects model. Fifty-three studies (n=6129) met the inclusion criteria. Perioperative GIK infusion was effective in reducing MI (k=32 OR 0.66[0.48, 0.89] P=0.0069), acute kidney injury (k=7 OR 0.57[0.4, 0.82] P=0.0023) and hospital length of stay (k=19 MD -0.89[-1.63, -0.16] days P=0.0175). Postoperatively, the GIK-treated group presented higher cardiac index (k=14 MD 0.43[0.29, 0.57] L/min P<0.0001) and lesser hyperglycemia (k=20 MD -30[-47, -13] mg/dL P=0.0005) than in the usual care group. The GIK-associated protection for MI was effective when insulin infusion rate exceeded 2 mUI/kg/min and after coronary artery bypass surgery. Certainty of evidence was low given imprecision of the effect estimate, heterogeneity in outcome definition and risk of bias. Perioperative GIK infusion is associated with improved early outcome and reduced hospital resource utilization after cardiac surgery. Supporting evidence is heterogenous and further research is needed to standardize the optimal timing and composition of GIK solutions.

Patent foramen ovale and perioperative stroke in noncardiac surgery: a systematic review and meta-analysis.

BACKGROUND: Patent foramen ovale (PFO) is associated with perioperative stroke in noncardiac surgery. The magnitude of this association was assessed in a systematic review and meta-analysis. METHODS: Electronic databases were searched up to June 2022 for studies assessing the association between patent foramen ovale and perioperative stroke in adult patients undergoing noncardiac surgery. The primary analysis was limited to studies reporting effect estimates adjusted for significant clinical confounders. We calculated the adjusted odds ratio (aOR) and 95% confidence interval (CI). RESULTS: We included nine retrospective and two prospective observational studies, including 21 257 082 patients. The presence of a patent foramen ovale was independently associated with stroke at 30 days after surgery (aOR=6.68 [95% CI: 3.51-12.73]; P<0.001) and at longest follow-up available (aOR=7.36 [95% CI: 3.56-15.21]; P<0.001). The odds of stroke at 30 days varied according to surgical specialty: neurosurgery (aOR=4.52 [95% CI: 3.17-6.43]), vascular surgery (aOR=7.15 [95% CI: 2.52-20.22]), thoracic surgery (aOR=10.64 [95% CI: 5.97-18.98]), orthopaedic surgery (aOR=11.85 [95% CI: 5.38-26.08]), general surgery (aOR=14.40 [95% CI: 10.88-19.06]), and genitourinary surgery (aOR=17.28 [95% CI: 10.36-28.84]). CONCLUSIONS: The presence of a patent foramen ovale is associated with a large and consistent increase in odds of stroke across all explored surgical settings. Prospective trials should further explore this association by systematically assessing patent foramen ovale and stroke prevalence and identifying a specific population at risk. This is crucial for the elaboration of prevention plans and may improve perioperative outcomes.

Mortality and adverse events of hemoadsorption with CytoSorb® in critically ill patients: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The effects and safety of extracorporeal hemoadsorption with CytoSorb® in critically ill patients with inflammatory conditions are controversial. METHODS: We performed a systematic review with meta-analysis and trial sequential analysis (TSA) of randomized-controlled trials to assess the mortality and safety of CytoSorb® therapy in critically ill patients with inflammatory conditions. Electronic databases were searched up to April 2022. The primary outcome was mortality at longest follow-up and secondary outcomes included various adverse event (AE) outcomes. Conflict of interest and funding of each trial were assessed. We calculated relative risk (RR) and 95% confidence interval (CI). RESULTS: Fourteen published (n = 764) and 4 unpublished (n = 111) trials were included. Eight trials were performed in medical ICU patients and 10 in complex cardiac surgery. Ten trials had significant industrial funding or an author conflict of interest. Hemoadsorption with CytoSorb® was associated with higher mortality at latest follow-up (16 trials, n = 807, 120 of 402 [29.85%] patients in the CytoSorb® group vs. 98 of 405 [24.20%] patients in the control group, RR = 1.24 [95% CI, 1.04-1.49], p = .02, [TSA-adjusted CI, 0.92-1.68]) and at 30-days or in-hospital (11 trials, n = 727; RR = 1.41 [95% CI, 1.06-1.88], p = .02, [TSA-adjusted CI, 0.44-4.62]). Only one trial reported the definition of adverse event, while detailed results were reported in 3 trials; the risk of adverse events was not higher with CytoSorb®. Certainty of evidence ranged from low to very low. CONCLUSION: Low certainty of evidence showed that the use of CytoSorb® might increase mortality in critically ill patients with inflammatory conditions. Adverse events were frequent but underreported and not systematically evaluated. Industrial funding and conflict of interest were common. Considerable uncertainty about the findings does not allow firm conclusions and suggests a need for high-quality randomized trials to clarify mortality and adverse events related to CytoSorb®. EDITORIAL COMMENT: Hemoadsorption with CytoSorb® have been used in critically ill patients despite lack of high quality data from RCTs suggesting any patient-important benefits. The findings from this systematic review and meta-analysis suggests an increased risk of adverse events including mortality. With no apparent benefits and at the same time risk of harm, use of hemoadsorption with CytoSorb® in daily clinical practice cannot be recommended at this time.

Efficacy and safety of perioperative vitamin C in patients undergoing noncardiac surgery: a systematic review and meta-analysis of randomised trials.

BACKGROUND: Perioperative oxidative stress plays a role in organ injury and pain and could be improved by the antioxidant effects of vitamin C. METHODS: We performed a systematic review and meta-analysis of RCTs comparing perioperative vitamin C administration vs placebo or no treatment in adults undergoing noncardiac surgery. The primary outcome was hospital length of stay (LOS). RESULTS: Thirty-seven RCTs and 2747 patients were included. Administration of vitamin C was associated with no difference in LOS (mean difference=0.02 day; 95% confidence interval [CI], -0.30 to 0.35; P=0.88). Mortality did not differ between groups (relative risk=1.04; 95% CI, 0.52 to 2.08; P=0.5). No trials reported on other major postoperative complications. Vitamin C was associated with a reduction in postoperative pain score and cumulative morphine consumption up to 48 h after surgery. The incidence of complex regional pain syndrome was lower in orthopaedic patients receiving vitamin C. Adverse events were present in three RCTs (n=157), absent in 10 RCTs (n=957), and not reported in 25 RCTs (n=1570). One trial (n=20) in kidney transplantation surgery was stopped early because of safety concerns on vitamin C. The quality of evidence ranged from moderate to very low. CONCLUSIONS: Administration of vitamin C was not associated with a decrease in LOS after noncardiac surgery. The effects on morbidity and mortality are inconclusive and mostly uninvestigated. A small reduction in postoperative pain was found. Adverse events were rare but not systematically assessed. The evidence is uncertain, not supporting the use of vitamin C outside an experimental setting. STUDY PROTOCOL: PROSPERO database, CRD42021241654.

Percutaneous coronary intervention versus coronary artery bypass graft for left main coronary artery disease: A meta-analysis.

BACKGROUND: The optimal revascularization strategy for patients with left main coronary artery disease is still controversial. This is systematic review and meta-analysis aims to evaluate the outcomes of percutaneous coronary intervention (PCI) with drug-eluting stents compared with coronary artery bypass graft (CABG) for LM disease. METHODS: Online electronic databases were systematically reviewed until January 2020 for randomized trials comparing PCI with drug-eluting stents and CABG. Primary outcomes were: all-cause mortality, myocardial infarction (MI), stroke, and repeated revascularization. Secondary outcomes included periprocedural and nonperiprocedural MI. The period of follow-up included 30 days, 1 year, and 5 years. Odds ratio and 95% confidence interval were calculated with a fixed-effects model. RESULTS: A total of 4595 patients (5 randomized trials) with left main coronary artery disease were included. At 30 days and 1 year, PCI was associated with lower incidence of stroke, higher repeated revascularization, and similar odds of mortality and MI compared with CABG. At 5 years, PCI was associated with higher rates of MI (odds ratio, 1.43; 95% confidence interval, 1.13-1.79; P = .003) and repeat revascularization (odds ratio, 1.89; 95% CI, 1.58-2.26; P < .001) than CABG. PCI was associated with lower periprocedural MI at 30 days, whereas at 5 years PCI was associated with higher nonperiprocedural MI (odds ratio, 2.32; 95% confidence interval, 1.62-3.31; P < .001). Mortality and stroke rate did not differ at 5-year follow-up. CONCLUSIONS: Patients with left main coronary artery disease treated with either PCI or CABG do not show significant difference in early or 5-year mortality. Although CABG was associated with higher stroke rates at 30 days and 1 year, PCI was associated with an increase in MI and need for repeat revascularization at 5 years.

Effect of adjunctive vitamin C, glucocorticoids, and vitamin B1 on longer-term mortality in adults with sepsis or septic shock: a systematic review and a component network meta-analysis.

We aimed to compare the effects of vitamin C, glucocorticoids, vitamin B1, combinations of these drugs, and placebo or usual care on longer-term mortality in adults with sepsis or septic shock. MEDLINE, Embase, CENTRAL, ClinicalTrials.gov and WHO-ICTRP were searched. The final search was carried out on September 3rd, 2021. Multiple reviewers independently selected randomized controlled trials (RCTs) comparing very-high-dose vitamin C (≥ 12 g/day), high-dose vitamin C (< 12, ≥ 6 g/day), vitamin C (< 6 g/day), glucocorticoid (< 400 mg/day of hydrocortisone), vitamin B1, combinations of these drugs, and placebo/usual care. We performed random-effects network meta-analysis and, where applicable, a random-effects component network meta-analysis. We used the Confidence in Network Meta-Analysis framework to assess the degree of treatment effect certainty. The primary outcome was longer-term mortality (90-days to 1-year). Secondary outcomes were severity of organ dysfunction over 72 h, time to cessation of vasopressor therapy, and length of stay in intensive care unit (ICU). Forty-three RCTs (10,257 patients) were eligible. There were no significant differences in longer-term mortality between treatments and placebo/usual care or between treatments (10 RCTs, 7,096 patients, moderate to very-low-certainty). We did not find any evidence that vitamin C or B1 affect organ dysfunction or ICU length of stay. Adding glucocorticoid to other treatments shortened duration of vasopressor therapy (incremental mean difference, - 29.8 h [95% CI - 44.1 to - 15.5]) and ICU stay (incremental mean difference, - 1.3 days [95% CI - 2.2 to - 0.3]). Metabolic resuscitation with vitamin C, glucocorticoids, vitamin B1, or combinations of these drugs was not significantly associated with a decrease in longer-term mortality.

Therapeutic Hypothermia in Critically Ill Patients: A Systematic Review and Meta-Analysis of High Quality Randomized Trials.

OBJECTIVES: To investigate the effect of the application of therapeutic hypothermia (32-35°C) on survival and major clinical endpoints in critically ill patients. DATA SOURCES: We searched online database and clinical trial registries dated up to April 30, 2019, and references of relevant studies. STUDY SELECTION: Low risk of bias randomized trials which compared hypothermia applied for at least 24 hours and conventional therapy in critically ill patients were included. We excluded trials investigating therapeutic hypothermia in indications already supported by international guidelines (adult cardiac arrest and hypoxic-ischemic encephalopathy of newborns) or intraoperative hypothermia. DATA EXTRACTION: Titles and abstracts were reviewed independently by two authors. If the articles seemed eligible, full-text articles were reviewed, and data were abstracted using a structured template. DATA SYNTHESIS: Our search retained 14 low risk of bias randomized trials (2,670 patients) performed in three different settings: traumatic brain injury, serious infections, and stroke. Therapeutic hypothermia was associated with an increase in mortality at longest follow-up available (432/1,375 [31%] vs 330/1,295 [25%]; risk ratio, 1.24; 95% CI, 1.10-1.39; p = 0.0004; I = 0%). Pooled results showed no difference of good neurologic outcome among survivors between the two treatment arms (493/1,142 [43%] vs 486/1,067 [46%]; risk ratio, 1.04; 95% CI, 0.97-1.12; p = 0.27; I = 1%). Arrhythmias were significantly increased among patients undergoing therapeutic hypothermia. We found no difference between groups in pneumonia, serious infections, any infection, hemorrhage, renal failure, deep vein thrombosis, and uncontrollable intracranial hypertension. CONCLUSIONS: High-quality randomized evidence indicates that therapeutic hypothermia is associated with higher mortality and no difference in good neurologic outcome compared with normothermia in critically ill patients. Although there still might be a possibility that therapeutic hypothermia is beneficial in a specific setting, routine application of therapeutic hypothermia would better be avoided outside the settings indicated by international guidelines (adult cardiac arrest and hypoxic-ischemic encephalopathy of newborns).

The influence of postoperative albumin levels on the outcome of cardiac surgery.

BACKGROUND: The prognostic role of low postoperative serum albumin levels (SAL) after cardiac surgery (CS) remains unclear in patients with normal preoperative SAL. Our aim was to evaluate the influence of SAL on the outcome of CS. METHODS: Prospective observational study. Patients undergoing CS with normal preoperative SAL and nutritional status were included and classified into different subgroups based on SAL at 24 h after CS. We assessed outcomes (i.e., in-hospital mortality, postoperative complications and long-term survival) and results were analyzed among the different subgroups of SAL. RESULTS: We included 2818 patients. Mean age was 64.5 ± 11.6 years and body mass index 28.0 ± 4.3Kg·m- 2. 5.8%(n = 162) of the patients had normal SAL levels(≥35 g·L- 1), 32.8%(n = 924) low deficit (30-34.9 g·L- 1), 44.3%(n = 1249) moderate deficit (25-29.9 g·L- 1), and 17.1%(n = 483) severe deficit(< 25 g·L- 1). Higher SAL after CS was associated with reduced in-hospital (OR:0.84;95% CI:0.80-0.84; P = 0.007) and long-term mortality (HR:0.85;95% CI:0.82-0.87;P < 0.001). Subgroups of patients with lower SAL showed worst long-term survival (5-year mortality:94.3% normal subgroup, 87.4% low, 83.1% moderate and 72.4% severe;P < 0.001). Multivariable analysis showed higher in-hospital mortality, sepsis, hemorrhage related complications, and ICU stay in subgroups of patients with lower SAL. Predictors of moderate and severe hypoalbuminemia were preoperative chronic kidney disease, previous CS, and longer cardiopulmonary bypass time. CONCLUSIONS: The presence of postoperative hypoalbuminemia after CS is frequent and the degree of hypoalbuminemia may be associated with worst outcomes, even in the long-term scenario.

The optimal dose of succinylcholine for rapid sequence induction: a systematic review and meta-analysis of randomized trials.

BACKGROUND: The evidence base for the widely accepted standard regimen of succinylcholine for rapid sequence induction (1.0 mg kg- 1) remains unclear. METHODS: We performed a systematic review and meta-analysis of randomized trials comparing any succinylcholine regimen with the standard regimen (1.0 mg kg- 1) and reporting on intubating conditions and/or apnoea times. Results were expressed as absolute risk differences (ARD) for dichotomous data and mean differences (MD) for continuous data. RESULTS: We retrieved six trials with relevant data of 864 patients (ASA 1 or 2, aged 18-65 years, body mass index < 30 kg m- 2). Four regimens (0.3, 0.4, 0.5, 0.6 mg kg- 1) were compared with 1.0 mg kg- 1 in at least three trials each, and three (0.8, 1.5, 2 mg kg- 1) in one each. With 0.3 to 0.5 mg kg- 1, the likelihood of excellent intubating conditions was significantly decreased (ARD - 22% to - 67%). With 0.3 and 0.4 mg kg- 1, but not with 0.5, 0.6, 0.8, 1.5 and 2.0 mg kg- 1, the likelihood of unacceptable intubating conditions was significantly increased (ARD + 22% and + 32%, respectively). With 2.0 mg kg- 1, but not with 0.8 or 1.5 mg kg- 1, the likelihood of excellent intubating conditions was significantly increased (ARD + 23%). Apnoea times were significantly shorter with regimens ≤0.8 mg kg- 1 (MD - 1.0 to - 3.4 min) but were not reported with 1.5 or 2.0 mg kg- 1. CONCLUSIONS: With succinylcholine regimens ≤0.5 mg kg- 1, excellent intubating conditions are less likely and apnoea times are shorter, compared with 1 mg kg- 1. With 0.3 and 0.4 mg kg- 1, unacceptable intubating conditions are more common. Succinylcholine 1.5 mg kg- 1 does not produce more often excellent conditions compared with 1 mg kg- 1, while 2.0 mg kg- 1 does, but the database with these regimens is weak and apnoea times remain unknown. Limited information size and strong statistical heterogeneity decrease the certainty of the evidence.

Tracheal intubation in patients at risk for cervical spinal cord injury: A systematic review.

BACKGROUND: Tracheal intubation in patients at risk for secondary spinal cord injury is potentially difficult and risky. OBJECTIVES: To compare tracheal intubation techniques in adult patients at risk for secondary cervical spinal cord injury undergoing surgery. Primary outcome was first-attempt failure rate. Secondary outcomes were time to successful intubation and procedure complications. DESIGN: Systematic review and meta-analysis of randomized controlled trials (RCTs) with trial sequential analysis (TSA). DATA SOURCES: Databases searched up to July 2019. ELIGIBILITY: Randomized controlled trials comparing different intubation techniques. RESULTS: We included 18 trials enrolling 1972 patients. Four studies used the "awake" approach, but no study compared awake versus non-awake techniques. In remaining 14 RCTs, intubation was performed under general anesthesia. First-attempt failure rate was similar when comparing direct laryngoscopy or fiberoptic bronchoscopy versus other techniques. A better first-attempt failure rate was found with videolaryngoscopy and when pooling all the fiberoptic techniques together. All these results appeared not significant at TSA, suggesting inconclusive evidence. Intubating lighted stylet allowed faster intubation. Postoperative neurological complications were 0.34% (no significant difference among techniques). No life-threatening adverse event was reported; mild local complications were common (19.5%). The certainty of evidence was low to very low mainly due to high imprecision and indirectness. CONCLUSIONS: Videolaryngoscopy and fiberoptic-assisted techniques might be associated with higher first-attempt failure rate over controls. However, low to very low certainty of evidence does not allow firm conclusions on the best tracheal intubation in patients at risk for cervical spinal cord injury.