Prediction, prognosis, and professionalism in perioperative medicine.

Guidelines provide a framework to take better care of our patients. They are published by different professional groups and are based on all the research done for us by hardworking colleagues. Compiling a guideline is an enormous amount of work and is generally done with the utmost care. However, recommendations often require a subjective interpretation of published research, where personal and academic interests can influence the outcome. We discuss two recently published guidelines on perioperative cardiovascular assessment that led to different conclusions on some important areas of patient care.

Perioperative transfusion study (PETS): Does a liberal transfusion protocol improve outcome in high-risk cardiovascular patients undergoing non-cardiac surgery? A randomised controlled pilot study.

BACKGROUND: Small studies have shown that patients with advanced coronary artery disease might benefit from a more liberal blood transfusion strategy. The goal of this pilot study was to test the feasibility of a blood transfusion intervention in a group of vascular surgery patients who have elevated cardiac troponins in rest. METHODS: We conducted a single-centre, randomised controlled pilot study. Patients with a preoperative elevated high-sensitive troponin T undergoing non-cardiac vascular surgery were randomised between a liberal transfusion regime (haemoglobin >10.4 g/dL) and a restrictive transfusion regime (haemoglobin 8.0-9.6 g/dL) during the first 3 days after surgery. The primary outcome was defined as a composite endpoint of all-cause mortality, myocardial infarction or unscheduled coronary revascularization. RESULTS: In total 499 patients were screened; 92 were included and 50 patients were randomised. Postoperative haemoglobin was different between the intervention and control group; 10.6 versus 9.8, 10.4 versus 9.4, 10.9 versus 9.4 g/dL on day one, two and three respectively (p < 0.05). The primary outcome occurred in four patients (16%) in the liberal transfusion group and in two patients (8%) in control group. CONCLUSION: This pilot study shows that the studied transfusion protocol was able to create a clinically significant difference in perioperative haemoglobin levels. Randomisation was possible in 10% of the screened patients. A large definitive trial should be possible to provide evidence whether a liberal transfusion strategy could decrease the incidence of postoperative myocardial infarction in high risk surgical patients.

Aneurysm Sac Dynamics and its Prognostic Significance Following Fenestrated and Branched Endovascular Aortic Aneurysm Repair.

OBJECTIVE: This study aimed to assess aneurysm sac dynamics and its prognostic significance following fenestrated and branched endovascular aneurysm repair (F/BEVAR). METHODS: Patients undergoing F/BEVAR for degenerative complex aortic aneurysm from 2008 to 2020 at two large vascular centres with two imaging examinations (30 day and one year) were included. Patients were categorised as regression and non-regression, determined by the proportional volume change (> 5%) at one year compared with 30 days. All cause mortality and freedom from graft related events were assessed using Kaplan-Meier methods. Factors associated with non-regression at one year and aneurysm sac volume over time were examined for FEVAR and BEVAR independently using multivariable logistic regression and linear mixed effects modelling. RESULTS: One hundred and sixty-five patients were included: 122 FEVAR, of whom 34% did not regress at one year imaging (20% stable, 14% expansion); and 43 BEVAR, of whom 53% failed to regress (26% stable, 28% expansion). Following F/BEVAR, after risk adjusted analysis, non-regression was associated with higher risk of all cause mortality within five years (hazard ratio [HR] 2.56, 95% confidence interval [CI] 1.09 - 5.37; p = .032) and higher risk of graft related events within five years (HR 2.44, 95% CI 1.10 - 5.26; p = .029). Following multivariable logistic regression, previous aortic repair (odds ratio [OR] 2.56, 95% CI 1.11 - 5.96; p = .029) and larger baseline aneurysm diameter (OR/mm 1.04, 95% CI 1.00 - 1.09; p = .037) were associated with non-regression at one year, whereas smoking history was inversely associated with non-regression (OR 0.21, 95% CI 0.04 - 0.96; p = .045). Overall following FEVAR, aneurysm sac volume decreased significantly up to two years (baseline vs. two year, 267 [95% CI 250 - 285] cm3vs. 223 [95% CI 197 - 248] cm3), remaining unchanged thereafter. Overall following BEVAR, aneurysm sac volume remained stable over time. CONCLUSION: Like infrarenal EVAR, non-regression at one year imaging is associated with higher five year all cause mortality and graft related events risks after F/BEVAR. Following FEVAR for juxtarenal aortic aneurysm, aneurysm sacs generally displayed regression (66% at one year), whereas after BEVAR for thoraco-abdominal aortic aneurysm, aneurysm sacs displayed a concerning proportion of growth at one year (28%), potentially suggesting a persistent risk of rupture and consequently requiring intensified surveillance following BEVAR. Future studies will have to elucidate how to improve sac regression following complex EVAR, and whether the high expansion risk after BEVAR is due to advanced disease extent.

Circulating biomarkers of cardiovascular disease are related to aneurysm volume in abdominal aortic aneurysm.

BACKGROUND: Surveillance programs in abdominal aortic aneurysms (AAA) are mainly based on imaging and leave room for improvement to timely identify patients at risk for AAA growth. Many biomarkers are dysregulated in patients with AAA, which fuels interest in biomarkers as indicators of disease progression. We examined associations of 92 cardiovascular disease (CVD)-related circulating biomarkers with AAA and sac volume. METHODS: In a cross-sectional analysis, we separately investigated (1) 110 watchful waiting (WW) patients (undergoing periodic surveillance imaging without planned intervention) and (2) 203 patients after endovascular aneurysm repair (EVAR). The Cardiovascular Panel III (Olink Proteomics AB, Sweden) was used to measure 92 CVD-related circulating biomarkers. We used cluster analyses to investigate protein-based subphenotypes, and linear regression to examine associations of biomarkers with AAA and sac volume on CT scans. RESULTS: Cluster analyses revealed two biomarker-based subgroups in both WW and EVAR patients, with higher levels of 76 and 74 proteins, respectively, in one subgroup versus the other. In WW patients, uPA showed a borderline significant association with AAA volume. Adjusting for clinical characteristics, there was a difference of -0.092 (-0.148, -0.036) loge mL in AAA volume per SD uPA. In EVAR patients, after multivariable adjustment, four biomarkers remained significantly associated with sac volume. The mean effects on sac volume per SD difference were: LDLR: -0.128 (-0.212, -0.044), TFPI: 0.139 (0.049, 0.229), TIMP4: 0.110 (0.023, 0.197), IGFBP-2: 0.103 (0.012, 0.194). CONCLUSION: LDLR, TFPI, TIMP4, and IGFBP-2 were independently associated with sac volume after EVAR. Subgroups of patients with high levels of the majority of CVD-related biomarkers emphasize the intertwined relationship between AAA and CVD.ClinicalTrials.gov Identifier: NCT03703947.

Prognostic models for outcome prediction following in-hospital cardiac arrest using pre-arrest factors: a systematic review, meta-analysis and critical appraisal.

BACKGROUND: Several prediction models of survival after in-hospital cardiac arrest (IHCA) have been published, but no overview of model performance and external validation exists. We performed a systematic review of the available prognostic models for outcome prediction of attempted resuscitation for IHCA using pre-arrest factors to enhance clinical decision-making through improved outcome prediction. METHODS: This systematic review followed the CHARMS and PRISMA guidelines. Medline, Embase, Web of Science were searched up to October 2021. Studies developing, updating or validating a prediction model with pre-arrest factors for any potential clinical outcome of attempted resuscitation for IHCA were included. Studies were appraised critically according to the PROBAST checklist. A random-effects meta-analysis was performed to pool AUROC values of externally validated models. RESULTS: Out of 2678 initial articles screened, 33 studies were included in this systematic review: 16 model development studies, 5 model updating studies and 12 model validation studies. The most frequently included pre-arrest factors included age, functional status, (metastatic) malignancy, heart disease, cerebrovascular events, respiratory, renal or hepatic insufficiency, hypotension and sepsis. Only six of the developed models have been independently validated in external populations. The GO-FAR score showed the best performance with a pooled AUROC of 0.78 (95% CI 0.69-0.85), versus 0.59 (95%CI 0.50-0.68) for the PAM and 0.62 (95% CI 0.49-0.74) for the PAR. CONCLUSIONS: Several prognostic models for clinical outcome after attempted resuscitation for IHCA have been published. Most have a moderate risk of bias and have not been validated externally. The GO-FAR score showed the most acceptable performance. Future research should focus on updating existing models for use in clinical settings, specifically pre-arrest counselling. Systematic review registration PROSPERO CRD42021269235. Registered 21 July 2021.

Needle-free pharmacological sedation techniques in paediatric patients for imaging procedures: a systematic review and meta-analysis.

BACKGROUND: Sedation techniques and drugs are increasingly used in children undergoing imaging procedures. In this systematic review and meta-analysis, we present an overview of literature concerning sedation of children aged 0-8 yr for magnetic resonance imaging (MRI) procedures using needle-free pharmacological techniques. METHODS: Embase, MEDLINE, Web of Science, and Cochrane databases were systematically searched for studies on the use of needle-free pharmacological sedation techniques for MRI procedures in children aged 0-8 yr. Studies using i.v. or i.m. medication or advanced airway devices were excluded. We performed a meta-analysis on sedation success rate. Secondary outcomes were onset time, duration, recovery, and adverse events. RESULTS: Sixty-seven studies were included, with 22 380 participants. The pooled success rate for oral chloral hydrate was 94% (95% confidence interval [CI]: 0.91-0.96); for oral chloral hydrate and intranasal dexmedetomidine 95% (95% CI: 0.92-0.97); for rectal, oral, or intranasal midazolam 36% (95% CI: 0.14-0.65); for oral pentobarbital 99% (95% CI: 0.90-1.00); for rectal thiopental 92% (95% CI: 0.85-0.96); for oral melatonin 75% (95% CI: 0.54-0.89); for intranasal dexmedetomidine 62% (95% CI: 0.38-0.82); for intranasal dexmedetomidine and midazolam 94% (95% CI: 0.78-0.99); and for inhaled sevoflurane 98% (95% CI: 0.97-0.99). CONCLUSIONS: We found a large variation in medication, dosage, and route of administration for needle-free sedation. Success rates for sedation techniques varied between 36% and 98%.

Alternatives to the in-person anaesthetist-led preoperative assessment in adults undergoing low-risk or intermediate-risk surgery: A scoping review.

BACKGROUND: The design of the optimal preoperative evaluation is a much debated topic, with the anaesthetist-led in-person evaluation being most widely used. This approach is possibly leading to overuse of a valuable resource, especially in low-risk patients. Without compromising patient safety, we hypothesised that not all patients would require this type of elaborate evaluation. OBJECTIVE: The current scoping review aims to critically appraise the range and nature of the existing literature investigating alternatives to the anaesthetist-led preoperative evaluation and their impact on outcomes, to inform future knowledge translation and ultimately improve perioperative clinical practice. DESIGN: A scoping review of the available literature. DATA SOURCES: Embase, Medline, Web-of-Science, Cochrane Library and Google Scholar. No date restriction was used. ELIGIBILITY CRITERIA: Studies in patients scheduled for elective low-risk or intermediate-risk surgery, which compared anaesthetist-led in-person preoperative evaluation with non-anaesthetist-led preoperative evaluation or no outpatient evaluation. The focus was on outcomes, including surgical cancellation, perioperative complications, patient satisfaction and costs. RESULTS: Twenty-six studies with a total of 361 719 patients were included, reporting on various interventions: telephone evaluation, telemedicine evaluation, evaluation by questionnaire, surgeon-led evaluation, nurse-led evaluation, other types of evaluation and no evaluation up to the day of surgery. Most studies were conducted in the United States and were either pre/post or one group post-test-only studies, with only two randomised controlled trials. Studies differed largely in outcome measures and were of moderate quality overall. CONCLUSIONS: A number of alternatives to the anaesthetists-led in-person preoperative evaluation have already been researched: that is telephone evaluation, telemedicine evaluation, evaluation by questionnaire and nurse-led evaluation. However, more high-quality research is needed to assess viability in terms of intraoperative or early postoperative complications, surgical cancellation, costs, and patient satisfaction in the form of Patient-Reported Outcome Measures and Patient-Reported Experience Measures.

Intermittent levosimendan infusion in ambulatory patients with end-stage heart failure: a systematic review and meta-analysis of 984 patients.

We sought to synthesize the available evidence regarding safety and efficacy of intermittent levosimendan (LEVO) infusions in ambulatory patients with end-stage heart failure (HF). Safety and efficacy of ambulatory intermittent LEVO infusion in patients with end-stage HF are yet not established. We systematically searched MEDLINE, EMBASE, SCOPUS, Web of Science, and Cochrane databases, from inception to January 30, 2021 for studies reporting outcome of adult ambulatory patients with end-stage HF treated with intermittent LEVO infusion. Fifteen studies (8 randomized and 7 observational) comprised 984 patients (LEVO [N = 727] and controls [N = 257]) met the inclusion criteria. LEVO was associated with improved New York Heart Association (NYHA) functional class (weighted mean difference [WMD] -1.04, 95%CI: -1.70 to -0.38, p < 0.001, 5 studies, I2 = 93%), improved left ventricular (LV) ejection fraction (WMD 4.0%, 95%CI: 2.8% to 5.3%, p < 0.001, 6 studies, I2 = 9%), and reduced BNP levels (WMD -549 pg/mL, 95%CI -866 to -233, p < 0001, 3 studies, I2 = 66%). All-cause death was not different (RR 0.65, 95%CI: 0.38 to 1.093, p = 0.10, 6 studies, I2 = 0), but cardiovascular death was lower on LEVO (RR 0.34, 95%CI: 0.13 to 0.87, p = 0.02, 3 studies, I2 = 0) compared to controls. Furthermore, health-related quality of life (HRQoL) was improved alongside with reduced LV size following LEVO infusions. Major adverse events were not different between LEVO and placebo. In conclusion, intermittent LEVO infusions in ambulatory patients with end-stage HF is associated with less frequent cardiovascular death alongside with improved NYHA class, quality of life, BNP levels, and LV function. However, the current evidence is limited by heterogeneous and relatively small studies.

Proximal seal dilatation following fenestrated endovascular repair for complex abdominal aortic aneurysms.

OBJECTIVE: Although proximal neck dilatation following infrarenal endovascular aneurysm repair (EVAR) is common and is associated with proximal graft failure, little is known about sealing zone dilatation and its clinical relevance following fenestrated EVAR (FEVAR). We studied proximal seal dilatation (PSD) dynamics following FEVAR and assessed its clinical significance. METHODS: We included all consecutive patients treated for a juxta-/supra-renal aneurysm with fenestrated EVAR using the Zenith Fenestrated Endovascular Graft (Cook Medical, Bloomington, Ind) from 2008 to 2018 in two large teaching hospitals in the Netherlands. The primary outcome was PSD over time and was determined using a linear mixed-effects model. Secondary outcomes included associations for early PSD and difference in aortic dilatation at the level of the covered stent compared with the bare stent. Proximal seal-related adverse events were also obtained. RESULTS: Our cohort included 84 patients with a median computed tomography angiography follow-up time of 24.5 months (interquartile range [IQR], 17-42 months). Maximum aneurysm diameter was 60.1 mm (IQR, 56.9-67.2 mm). Mean proximal seal diameter at baseline was 26.2 mm (standard deviation [SD], ±2.8 mm), mean stent oversizing was 20.1% (SD, ±9.1%), and mean proximal seal length was 29.5 mm (SD, ±11.7 mm). Proximal seal dilatation of 1.7 mm (95% confidence interval [CI], 1.4-2.1 mm) was found in the first year, decelerating thereafter (second year, 0.9 mm/year; 95% CI, 0.7-1.1 mm/y). Over 10% PSD at 1 year occurred in 22 patients (27%) and was associated with stent graft oversizing (odds ratio, 1.1; 95% CI, 1.03-1.2; P = .008) and a lower number of target vessels (four fenestrations/ref two fenestrations: odds ratio, 0.13; 95% CI, 0.02-0.74; P = .029). At last available imaging, dilatation difference was higher at the level of the covered stent compared with the bare stent (3.0 mm [IQR, 1.3-5.1 mm] vs 1.6 mm [IQR, 0.8-2.5 mm]; P < .001). During the study period, only one patient (1.2%) developed a proximal seal-related adverse event (type IA endoleak). CONCLUSIONS: PSD is present following FEVAR, occurring at a faster rate in the first year and subsequently decelerating thereafter, similarly to neck dilatation after standard infrarenal EVAR. Although its clinical implication seems to remain limited in the first years following implantation, further research is required to assess the effect of PSD on long-term FEVAR outcomes.

Perioperative Mortality in Pediatric Patients: A Systematic Review of Risk Assessment Tools for Use in the Preoperative Setting.

BACKGROUND: There are multiple preoperative risk scores for pediatric mortality. The aim of this study was to systematically describe and compare the existing studies of patient-specific multispecialty risk prediction scores for perioperative mortality in pediatric populations, with the goal of guiding clinicians on which may be most appropriate for use in the preoperative setting. METHODS: This study is a systematic literature review of published journal articles that presented the development, extension/updating, and/or validation of a risk core that predicted all-cause mortality (up to 30 days postoperatively) in pediatric patients undergoing a procedure in which anesthesia was used. Scores needed to be applicable to surgeries in more than one noncardiac surgical specialty and had to be able to be calculated by the anesthesiologist at the time of the preanesthetic assessment. Two investigators independently screened studies for inclusion and assessed study quality in the domains of clinical applicability, feasibility/ease of use in the clinical setting, and risk of bias. RESULTS: A total of 1,681 titles were retrieved. Of these, 10 studies met inclusion criteria: 9 reported the development and validation of scores, and 1 was an external validation of an existing score. Seven studies used varying years of multicenter data from the National Surgical Quality Improvement Program-Pediatric Participant Use File for development and/or validation. The unadjusted rate of mortality in the studies ranged from 0.3 to 3.6%. The preoperative predictors of mortality used in score development included patient demographics, preoperative therapies, and chronic conditions, among others. All models showed good discrimination upon validation (area under the receiver operating characteristics curve greater than 0.8). Most risk scores had high or unclear risks of bias. CONCLUSIONS: There are numerous scores available for the prediction of mortality in pediatric populations, all of which exhibited good performance. However, many have high or unclear risks of bias, and most have not undergone external validation.

Supervised Exercise Therapy is Effective for Patients With Intermittent Claudication Regardless of Psychological Constructs.

OBJECTIVE: According to current guidelines, supervised exercise therapy (SET) is the treatment of choice for intermittent claudication (IC). Little is known about the potential consequences of psychological factors on the effectiveness of treatment. The aim of this study was to determine possible associations between a set of psychological constructs and treatment outcomes, and to investigate whether self efficacy increased after SET. METHODS: This was a substudy of the ELECT Registry, a multicentre Dutch prospective cohort study in patients with IC receiving primary SET. A complete set of validated questionnaires scoring extraversion, neuroticism, conscientiousness, anxiety, depression, self control, optimism, and self efficacy was obtained in 237 patients (median age 69 years, 40% female). Anxiety and depression were dichotomised using established cutoff scores, whereas other scores were analysed as continuous measures. Multiple linear regression analyses determined possible associations between these independent variables and maximum and functional walking distances (MWD and FWD, respectively), Six Minute Walk Test (6MWT), and VascuQol-6 (dependent variables). Self efficacy during 12 months of SET was analysed using a linear mixed model. RESULTS: Neuroticism and anxiety were associated with lower overall VascuQol-6 scores (estimate -1.35 points [standard error (SE) 0.57; p = .018] and -1.98 points [SE 0.87, p = .023], respectively). Optimism and self efficacy demonstrated higher overall 6MWT (5.92 m [SE 2.34; p = .012] and 1.35 m [SE 0.42; p = .001], respectively). Self control was associated with lower overall log MWD (-0.02 [SE 0.01; p = .038] and log FWD (-0.02 [SE 0.01; p = .080), whereas self efficacy had a higher overall log MWD (0.01 [SE 0.003; p = .009]) and log FWD (0.01 [SE 0.003; p = .011]). Depressive patients with IC demonstrated a greater improvement in 6MWT during follow up (17.56 m [SE 8.67; p = .044]), but this small effect was not confirmed in sensitivity analysis. Self efficacy did not increase during follow up (0.12% [SE 0.49; p = .080]). CONCLUSIONS: The beneficial effects of SET occur regardless of the psychological constructs, supporting current guidelines recommending a SET first strategy in each patient with IC.

Incidence, Prognostic Significance, and Risk Factors of Acute Kidney Injury Following Elective Infrarenal and Complex Endovascular Aneurysm Repair.

OBJECTIVE: Acute kidney injury (AKI) is a well known complication following cardiovascular procedures. The objective was to assess the incidence, risk factors, and prognostic significance of AKI after infrarenal endovascular aneurysm repair (EVAR) and complex EVAR (cEVAR; fenestrated or branched EVAR). METHODS: Consecutive patients undergoing elective infrarenal EVAR or cEVAR between 2000 and 2018 in two large teaching hospitals in the Netherlands were included. AKI was determined by serum creatinine levels increasing > 1.5 times or by an absolute increase of 26.5 mmol/L from baseline value (KDIGO criteria). The primary outcome was incidence of peri-operative AKI development. Secondary outcomes included mid-term renal function (RIFLE criteria), overall survival, and risk factors for AKI development. To determine survival and risk factors for AKI, multivariable Cox regression and logistic regression analyses were performed, accounting for pre-operative renal function and other confounders. RESULTS: In total, 540 patients who underwent infrarenal EVAR with 147 patients who underwent cEVAR also included. The incidence of AKI was 8.7% (n = 47) in infrarenal EVAR patients and 23% (n = 34) in cEVAR patients (fenestrated EVAR 18%; branched EVAR 38%). In contrast to patients without AKI, the renal function of surviving patients with AKI remained significantly reduced at six weeks and did not return to pre-operative values following infrarenal EVAR (three year estimated glomerular filtration rate [eGFR] 59.3 ± 23.1 mL/min/1.73m2vs. pre-operative eGFR 74.0 ± 21.7 mL/min/1.73m2; p = .006) or following cEVAR (three year eGFR 52.0 ± 23.7 mL/min/1.73m2vs. pre-operative eGFR 65.4 ± 18.6 mL/min/1.73m2; p = .082). After risk adjusted analysis, compared with non-AKI, post-operative AKI development was associated with a higher three year mortality rate following both infrarenal and cEVAR (infrarenal EVAR mortality hazard ratio [HR 1.6, 95% confidence interval [CI] 1.01 - 2.7 [p = .046]; cEVAR mortality HR 2.4, 95% CI 1.1 - 5.2 [p = .033]). Following multivariable logistic regression, pre-operative chronic kidney disease (eGFR < 60 mL/min/1.73m2; odds ratio [OR] 2.2, 95% CI 1.03 - 4.8) and neck diameter (OR 1.1, 95% CI 1.01 - 1.2) were significantly associated with AKI following infrarenal EVAR, whereas for cEVAR only contrast volume (OR 1.1, 95% CI 1.0 - 1.2]) was found to be statistically significantly associated with AKI. CONCLUSION: AKI is a well described complication following infrarenal EVAR and is common after cEVAR. As AKI seems to be associated with permanent renal deterioration and lower survival, efforts to prevent AKI are essential. Future studies are required to assess what factors are associated with a higher risk of developing AKI following cEVAR.

Rotational Thromboelastometry-Guided Transfusion Protocol to Reduce Allogeneic Blood Transfusion in Proximal Aortic Surgery With Deep Hypothermic Circulatory Arrest.

OBJECTIVES: To determine the impact of a rotational thromboelastometry (ROTEM)-guided transfusion protocol on the use of blood products, patient outcomes, coagulation factor concentrates, and costs. DESIGN: A single-center retrospective cohort study. SETTING: A tertiary university hospital. PATIENTS: Adults undergoing proximal aortic surgery with deep hypothermic circulatory arrest. INTERVENTION: ROTEM-guided transfusion protocol compared with clinically-guided transfusion. MEASUREMENTS AND MAIN RESULTS: Two hundred seventeen patients were included; seventy-one elective and 24 emergency patients in the clinically-guided group, and 59 elective and 63 emergency patients in the ROTEM-guided transfusion protocol group. In the ROTEM-guided transfusion protocol group, a significant reduction in transfusion of red blood cells (5 [3-8] v 2 [0-4], p < 0.001), platelet concentrate (2 [2-3] v 1 [1-2], p < 0.001), and plasma (1,980 mL [1,320-3,300] v 800 mL [0-1,000], p < 0.001) was seen in elective surgery. Emergency patients received fewer red blood cells (7 [5-10] v 5 [2-10], p = 0.040), platelet concentrate (3 [2-4] v 2 [2-3], p = 0.023), and plasma (3,140 mL [1,980-3,960] v 1,000 mL [0-1,400], p < 0.001). Prothrombin complex concentrate and fibrinogen concentrate were increased significantly in elective and emergency patients. The surgical reexploration for bleeding rate was decreased in elective patients 33.8% v 5.1%. CONCLUSION: The implementation of a ROTEM-guided transfusion protocol might have the potential to decrease blood product transfusion and may improve patient outcomes.

Validation of a new combined transcutaneous tcPCO2 and tcPO2 sensor in children in the operating theater.

BACKGROUND: Arterial blood gas analysis is the gold standard for monitoring of Pa CO2 and PaO2 during mechanical ventilation. However, continuous measurements would be preferred. Transcutaneous sensors continuously measure blood gases diffusing from the locally heated skin. These sensors have been validated in children mostly in intensive care settings. Accuracy in children during general anesthesia is largely unknown. AIMS: We conducted a study in children undergoing general anesthesia to validate the use and to determine the accuracy of continuous transcutaneous measurements of the partial pressures of PCO2 (tcPCO2 ) and PO2 (tcPO2 ). METHODS: A prospective observational study in a tertiary care pediatric hospital in The Netherlands, from April to October 2018, in children aged 0-18 years undergoing general anesthesia. Patients were included when endotracheally intubated and provided with an arterial catheter for regular blood sampling. Patients with a gestational age <31 weeks, burn victims, and patients with skin disease were excluded. TcPCO2 and tcPO2  measurements were performed with a SenTec OxiVenT™ sensor (SenTec AG). Accuracy was determined with an agreement analysis between arterial and transcutaneous PCO2 and PO2  values, and between arterial and endtidal PCO2 (etCO2 ) values, according to Bland and Altman, accounting for multiple measurements per subject. RESULTS: We included 53 patients (median age 4.1 years, IQR 0.7-14.4 years) and retrieved 175 samples. TcPCO2 -Pa CO2 agreement analysis provided a bias of 0.06 kPa (limits of agreement (LOA) -1.18 to 1.31), the etCO2 -Pa CO2 agreement showed a bias of -0.31 kPa (LOA -1.38 to 0.76). Results of the tcPO2 -PaO2 agreement showed a bias of 3.40 to 0.86* (mean tension) kPa. CONCLUSIONS: This study showed good agreement between Pa CO2 and tcPCO2 in children of all ages during general anesthesia. Both transcutaneous and endtidal CO2  measurements showed good accuracy. TcPO2 is only accurate under 6 months of age.

Observer Variability as a Determinant of Measurement Error of Ultrasonographic Measurements of the Optic Nerve Sheath Diameter: A Systematic Review.

BACKGROUND: Ultrasonographic measurements of the diameter of the sheath of the optic nerve can be used to assess intracranial pressure indirectly. These measurements come with measurement error. OBJECTIVE: Our aim was to estimate observer's measurement error as a determinant of ultrasonographic measurement variability of the optic nerve sheath diameter. METHODS: A systematic search of the literature was conducted in Embase, Medline, Web of Science, the Cochrane Central Register of Trials, and the first 200 articles of Google Scholar up to April 19, 2021. Inclusion criteria were the following: healthy adults, B-mode ultrasonography, and measurements 3 mm behind the retina. Studies were excluded if standard error of measurement could not be calculated. Nine studies featuring 389 participants (median 40; range 15-100) and 22 observers (median 2; range 1-4) were included. Standard error of measurement and minimal detectable differences were calculated to quantify observer variability. Quality and risk of bias were assessed with the Guidelines for Reporting Reliability and Agreement Studies. RESULTS: The standard error of measurement of the intra- and interobserver variability had a range of 0.10-0.41 mm and 0.14-0.42 mm, respectively. Minimal detectable difference of a single observer was 0.28-1.1 mm. Minimal detectable difference of multiple observers (range 2-4) was 0.40-1.1 mm. Quality assessment showed room for methodological improvement of included studies. CONCLUSIONS: The standard errors of measurement and minimal detectable differences of ultrasonographic measurements of the optic nerve sheath diameter found in this review with healthy participants indicate caution should be urged when interpreting results acquired with this measurement method in clinical context.

Impact of body mass index on growth hormone stimulation tests in children and adolescents: a systematic review and meta-analysis.

Peak stimulated growth hormone (GH) levels are known to decrease with increasing body mass index (BMI), possibly leading to overdiagnosis of GH deficiency (GHD) in children with overweight and obesity. However, current guidelines do not guide how to interpret the peak GH values of these children. This systematic review and meta-analysis aimed to study the effect of the BMI standard deviation score (SDS) on stimulated peak GH values in children, to identify potential moderators of this association, and to quantify the extent to which peak GH values in children with obesity are decreased. This systematic review was performed by the PRISMA guidelines. Medline, Embase, Cochrane, Web of Science, and Google Scholar databases were searched for studies reporting the impact of weight status on peak GH in children. Where possible, individual participant data was extracted and/or obtained from authors. Quality and risk of bias were evaluated using the Scottish Intercollegiate Guidelines Network (SIGN) checklists. The primary outcome was the association between peak GH values and BMI SDS. The pooled correlation coefficient r, 95% confidence interval (CI), and heterogeneity statistic I2 were calculated under a multilevel, random-effects model. In addition, exploratory moderator analyses and meta-regressions were performed to investigate the effects of sex, pubertal status, presence of syndromic obesity, mean age and mean BMI SDS on the study level. For the individual participant dataset, linear mixed-models regression analysis was performed with BMI SDS as the predictor and ln(peak GH) as the outcome, accounting for the different studies and GH stimulation agents used. In total, 58 studies were included, providing data on n = 5135 children (576 with individual participant data). Thirty-six (62%) studies had high, 19 (33%) medium, and 3 (5%) low risks of bias. Across all studies, a pooled r of -0.32 (95% CI -0.41 to -0.23, n = 2434 patients from k = 29 subcohorts, I2 = 75.2%) was found. In meta-regressions, larger proportions of males included were associated with weaker negative correlations (p = 0.04). Pubertal status, presence of syndromic obesity, mean age, and mean BMI SDS did not moderate the pooled r (all p > 0.05). Individual participant data analysis revealed a beta of -0.123 (95% CI -0.160 to -0.086, p < 0.0001), i.e. per one-point increase in BMI SDS, peak GH decreases by 11.6% (95% CI 8.3-14.8%). To our knowledge, this is the first systematic review and meta-analysis to investigate the impact of BMI SDS on peak GH values in children. It showed a significant negative relationship. Importantly, this relationship was already present in the normal range of BMI SDS and could lead to overdiagnosis of GHD in children with overweight and obesity. With the ever-rising prevalence of pediatric obesity, there is a need for BMI (SDS)-specific cutoff values for GH stimulation tests in children. Based on the evidence from this meta-analysis, we suggest the following weight status-adjusted cutoffs for GH stimulation tests that have cutoffs for children with normal weight of 5, 7, 10, and 20 µg/L: for overweight children: 4.6, 6.5, 9.3, and 18.6 µg/L; and for children with obesity: 4.3, 6.0, 8.6, and 17.3 µg/L.

Aneurysm Volumes After Endovascular Repair of Ruptured vs Intact Aortic Aneurysms: A Retrospective Observational Study.

PURPOSE: To compare changes in abdominal aortic aneurysm (AAA) sac volume between endovascular aneurysm repairs (EVAR) performed for ruptured (rEVAR) vs intact (iEVAR) AAAs and to determine the impact of early volume shrinkage on future complications. MATERIALS AND METHODS: A retrospective analysis was performed of all patients undergoing standard infrarenal EVAR from 2002 to 2016 at a tertiary referral institution. Only patients with degenerative AAAs and with 30-day and 1-year computed tomography angiography (CTA) imaging were included. Early sac shrinkage was defined as a volume sac reduction >10% between the first (<30-day) and the 1-year CTA. The primary endpoint was to compare AAA sac volume changes between patients undergoing rEVAR (n=51; mean age 71.0±8.5 years; 46 men) vs iEVAR (n=393; mean age 72.3±7.5 years; 350 men). Results are reported as the mean difference with the interquartile range (IQR Q1, Q3). The secondary endpoint was freedom from aneurysm-related complications after 1 year as determined by regression analysis; the results are presented as the hazard ratio (HR) and 95% confidence interval (CI). RESULTS: At baseline, the rEVAR group had larger aneurysms (p<0.001) and shorter (p<0.001) and more angulated (p=0.028) necks. Aneurysm sac volume decreased more in the rEVAR group during the first year [-26.3% (IQR -38.8%, -12.5%)] vs the iEVAR group [-11.9% (IQR -27.5%, 0); p<0.001]. However, after the first year, the change in sac volume was similar between the groups [-3.8% (IQR -32.9%, 31.9%) for rEVAR and -1.5% (IQR -20.9%, 13.6%) for iEVAR, p=0.74]. Endoleak occurrence during follow-up was similar between the groups. In the overall population, patients with early sac shrinkage had a lower incidence of complications after the 1-year examination (adjusted HR 0.59, 95% CI 0.39 to 0.89, p=0.01). CONCLUSION: EVAR patients treated for rupture have more pronounced aneurysm sac shrinkage compared with iEVAR patients during the first year after EVAR. Patients presenting with early shrinkage are less likely to encounter late complications. These parameters may be considered when tailoring surveillance protocols.

Long Term Outcomes of Post-Implantation Syndrome After Endovascular Aneurysm Repair.

OBJECTIVE: The aim of this study was to investigate the association between post-implantation syndrome (PIS) and long term outcomes, with emphasis on cardiovascular prognosis. METHODS: One hundred and forty-nine consecutive patients undergoing EVAR in a tertiary institution were previously included in a study investigating the risk factors and short term consequences of PIS (defined as tympanic temperature ≥ 38°C and CRP > 10 mg/L, after excluding complications with an effect on inflammatory markers). This study was based on a prospectively maintained database. Survival status was derived from inquiry of civil registry database information and causes of death from the Dutch Central Bureau of Statistics. The primary endpoint was cardiovascular events. Secondary endpoints were overall and specific cause mortality (cardiovascular, ischaemic heart disease, AAA, and cancer related mortality). Aneurysm sac dynamics and occurrence of endoleaks were also analysed. Survival estimates were obtained using Kaplan-Meier plots and a multivariable model was constructed to correct for confounders. RESULTS: The PIS incidence was 39% (58/149). At the time of surgery, patients had a mean age of 73 ± 7 years and were predominantly male. There were no baseline differences between the PIS and non-PIS groups. The median follow up was 6.4 years (3.2 - 8.3), similar in both groups (p = .81). There was no difference in cardiovascular events for PIS and non-PIS patients (p = .63). However, Kaplan-Meier plots suggest a trend towards a higher rate of cardiovascular events in PIS patients during the first years: freedom from cardiovascular events at one year was 94% vs. 89% and at three years 90% vs. 82%. No differences were found in overall and specific cause mortality. There was a higher rate of type II endoleaks for non-PIS patients (28% vs. 9%, p = .005). Sac dynamics were similar in both groups. CONCLUSION: The results suggest that PIS is not associated with a statistically significantly higher risk of cardiovascular events. PIS had no impact on mortality. Lastly, PIS patients had fewer type II endoleaks, but sac dynamics were analogous.

Risk Factors, Dynamics, and Clinical Consequences of Aortic Neck Dilatation after Standard Endovascular Aneurysm Repair.

OBJECTIVE: Aortic neck dilatation (AND) occurs after endovascular aneurysm repair (EVAR) with self expanding stent grafts (SESs). Whether it continues, ultimately exceeding the endograft diameter leading to abdominal aortic aneurysm (AAA) rupture, remains uncertain. Dynamics, risk factors, and clinical relevance of AND were investigated after EVAR with standard SESs. METHODS: All intact EVAR patients treated from 2000 to 2015 at a tertiary institution were included. Demographic, anatomical, and device related characteristics were investigated as risk factors for AND. Outer to outer diameters were measured at a single standardised aortic level on reconstructed computed tomography (CT) images. RESULTS: A total of 460 patients were included (median follow up 5.2 years, interquartile range [IQR] 3.0, 7.7 years; CT imaging follow up 3.3 years, IQR 1.3, 5.4). Baseline neck diameter was 24 mm (IQR 22, 26) and increased 11.1% (IQR 1.5%, 21.9%) at last CT imaging. Endograft oversizing was 20.0% (IQR 13.6, 28.0). AND was greater during the first year (5.2% [IQR 0, 11.7]) decreasing subsequently (two to four years to 1.4%/year [IQR 0.0, 4.5%], p ≤ .001) and was associated with suprarenal fixation endografts (t value = 7.9, p < .001) and oversizing (t value = 4.4, p < .001). AND exceeding the endograft was 3.5% (95% CI 2.2% - 4.8%) and 14.4% (95% CI 11.0% - 17.8%) at five and eight years, respectively. Excessive AND was associated with baseline neck diameter (OR 1.2/mm, 95% CI 1.05 - 1.41) while the Excluder endograft had a protective effect (OR 0.15, 95% CI 0.04 - 0.58). Excessive AND was associated with type 1A endoleak (HR 3.3, 95% CI 1.1 - 9.7) and endograft migration > 5 mm (HR 3.1, 95% CI 1.4 - 6.9). CONCLUSION: AND after EVAR with SES is associated with endograft oversizing and radial force but decelerates after the first post-operative year. Baseline aortic neck diameter and suprarenal stent bearing endografts were associated with an increased risk of AND beyond nominal stent graft diameter. However, it remains unclear whether patient selection, differences in endograft radial force or the suprarenal stent are accountable for this difference.

Long-term results after standard endovascular aneurysm repair with the Endurant and Excluder stent grafts.

OBJECTIVE: Many endografts are currently available for standard endovascular repair of infrarenal abdominal aortic aneurysms. Comparison of long-term outcomes between devices might aid in this decision process, but comparative data are scarce. The purpose of this study was to report long-term clinical outcomes of two commercially available endoprosthesis, the Endurant (Medtronic Vascular, Inc, Minneapolis, Minn) and the Excluder (W. L. Gore & Associates, Flagstaff, Ariz) stent grafts. METHODS: Patients undergoing standard endovascular repair from July 2004 to December 2011 in a single institution with the Endurant or the Low-Porosity Excluder endografts were eligible. Only patients treated for intact degenerative abdominal infrarenal aneurysms were included. All measurements were performed on center-lumen line reconstructions obtained on dedicated software. The primary end point was primary clinical success, defined as clinical success without the need for an additional or secondary surgical or endovascular procedure. Neck-related events (a composite of type IA endoleak, neck-related secondary intervention, or migration of >5 mm), neck morphology changes, renal function, and overall survival were secondary end points. RESULTS: The study included 277 patients (156 Endurants; 121 Excluders). The median follow-up was 5.8 years (range, 0.1-12.4 years) and did not differ between groups (P = .18). Patients treated with the Endurant stent graft had wider (neck diameter of >28 mm, 27.3% vs 1.7% [P < .001]; neck diameter of 27 mm, [interquartile range (IQR), 24-29 mm] for Endurant and 24 mm [IQR, 22-25 mm] for Excluder; P < .001) and more angulated necks (ß-angle of >60°, 26.7% vs 12.5%; P = .004). Oversizing was greater in the Endurant group (16% [IQR, 12%-22%] vs 13% [IQR, 8%-17%], respectively; P < .001). Patients were treated outside device instructions for use regarding proximal neck: 16.7% in the Endurant and 17.3% in the Excluder group (P = .720). The 7-year primary clinical success was 54.7% for the Endurant and 58.1% for the Excluder groups (P = .53). Freedom from neck-related events at 7 years was 76.7% for the Endurant and 78.8% for Excluder group (P = .94). The Endurant stent graft (hazard ratio [HR], 2.7; 95% confidence interval [CI], 1.3-5.8; P = .009) was an independent predictor of significant renal function decline. Neck dilatation was greater in Endurant-implanted patients (13% [95% CI, 2%-22%] vs 4% [95% CI, 0%-10%]; P < .001). Overall survival at 7 years was 61.4% in the Endurant and 50.3% (n = 50; standard error, 0.047) in the Excluder group (P = .39). CONCLUSIONS: This study reveals that durable and sustainable results can be obtained with either of these late generation devices. This finding suggests that careful planning and a tailored device selection taking into account the patient's anatomy are more relevant determinants than the graft model itself to obtain clinical success. The Endurant endoprosthesis seems to be associated with a higher rate of neck dilatation and faster decrease in the estimated glomerular filtration rate, but further studies with longer follow-up are necessary to determine the clinical relevance of these findings.