Perioperative arterial cannulation in children is routinely performed. Based on clinical observation of several complications related to femoral arterial lines, the authors performed a larger study ...to further examine complications. The authors aimed to (1) describe the use patterns and incidence of major short-term complications associated with arterial cannulation for perioperative monitoring in children, and (2) describe the rates of major complications by anatomical site and age category of the patient.
The authors examined a retrospective cohort of pediatric patients (age less than 18 yr) undergoing surgical procedures at a single academic medical center from January 1, 2006 to August 15, 2016. Institutional databases containing anesthetic care, arterial cannulation, and postoperative complications information were queried to identify vascular, neurologic, and infectious short term complications within 30 days of arterial cannulation.
There were 5,142 arterial cannulations performed in 4,178 patients. The most common sites for arterial cannulation were the radial (N = 3,395 66.0%) and femoral arteries (N = 1,528 29.7%). There were 11 major complications: 8 vascular and 3 infections (overall incidence, 0.2%; rate, 2 per 1,000 lines; 95% CI, 1 to 4) and all of these complications were associated with femoral arterial lines in children younger than 5 yr old (0.7%; rate, 7 per 1,000 lines; 95% CI, 4 to 13). The majority of femoral lines were placed for cardiac procedures (91%). Infants and neonates had the greatest complication rates (16 and 11 per 1,000 lines, respectively; 95% CI, 7 to 34 and 3 to 39, respectively).
The overall major complication rate of arterial cannulation for monitoring purposes in children is low (0.2%). All complications occurred in femoral arterial lines in children younger than 5 yr of age, with the greatest complication rates in infants and neonates. There were no complications in distal arterial cannulation sites, including more than 3,000 radial cannulations.
Recurrent ventricular tachycardia (VT) is an important cause of mortality and morbidity late after myocardial infarction. With frequent use of implantable cardioverter-defibrillators, these VTs are ...often poorly defined and not tolerated for mapping, factors previously viewed as relative contraindications to ablation. This observational multicenter study assessed the outcome of VT ablation with a saline-irrigated catheter combined with an electroanatomic mapping system.
Two hundred thirty-one patients (median LV ejection fraction, 0.25; heart failure in 62%) with recurrent episodes of monomorphic VT (median, 11 in the preceding 6 months) caused by prior myocardial infarction were enrolled. All inducible monomorphic VTs with a rate approximating or slower than any spontaneous VTs were targeted for ablation guided by electroanatomic mapping during sinus rhythm and/or VT. Patients were not excluded for multiple VTs (median, 3 per patient) or unmappable VT (present in 69% of patients). Ablation abolished all inducible VTs in 49% of patients. The primary end point of freedom from recurrent incessant VT or intermittent VT after 6 months of follow-up was achieved for 123 patients (53%). In 142 patients with implantable cardioverter-defibrillators before and after ablation for intermittent VT who survived 6 months, VT episodes were reduced from a median of 11.5 to 0 (P<0.0001). The 1-year mortality rate was 18%, with 72.5% of deaths attributed to ventricular arrhythmias or heart failure. The procedure mortality rate was 3%, with no strokes.
Catheter ablation is a reasonable option to reduce episodes of recurrent VT in patients with prior myocardial infarction, even when multiple and/or unmappable VTs are present. This population remains at high risk for death, warranting surveillance and further study.
Amidst controversy about methodology and safety, intraoperative neurophysiology has entered a new era of increasingly routine transcranial and direct electrical brain stimulation for motor evoked ...potential (MEP) monitoring. Based on literature review and illustrative clinical experience, this tutorial aims to present a balanced overview for experienced practitioners, surgeons and anesthesiologists as well as those new to the field. It details the physiologic basis, indications and methodology of current MEP monitoring techniques, evaluates their safety, explores interpretive controversies and outlines some applications and results, including aortic aneurysm, intramedullary spinal cord tumor, spinal deformity, posterior fossa tumor, intracranial aneurysm and peri-rolandic brain surgeries. The many advances in motor system assessment achieved in the last two decades undoubtedly improve monitoring efficacy without unduly compromising safety. Future studies and experience will likely clarify existing controversies and bring further advances.
Intraoperative mortality is now rare, but death within 30 days of surgery remains surprisingly common. Perioperative myocardial infarction is associated with a remarkably high mortality. There are ...strong associations between hypotension and myocardial injury, myocardial infarction, renal injury, and death. Perioperative arterial blood pressure management was thus the basis of a Perioperative Quality Initiative consensus-building conference held in London in July 2017.
The meeting featured a modified Delphi process in which groups addressed various aspects of perioperative arterial pressure.
Three consensus statements on intraoperative blood pressure were established. 1) Intraoperative mean arterial pressures below 60–70 mm Hg are associated with myocardial injury, acute kidney injury, and death. Injury is a function of hypotension severity and duration. 2) For adult non-cardiac surgical patients, there is insufficient evidence to recommend a general upper limit of arterial pressure at which therapy should be initiated, although pressures above 160 mm Hg have been associated with myocardial injury and infarction. 3) During cardiac surgery, intraoperative systolic arterial pressure above 140 mm Hg is associated with increased 30 day mortality. Injury is a function of arterial pressure severity and duration.
There is increasing evidence that even brief durations of systolic arterial pressure <100 mm Hg and mean arterial pressure <60–70 mm Hg are harmful during non-cardiac surgery.
It has been suggested that longer-term postsurgical outcome may be adversely affected by less than severe hypotension under anesthesia. However, evidence-based guidelines are unavailable. The present ...study was designed to develop a method for identifying patients at increased risk of death within 30 days in association with the severity and duration of intraoperative hypotension.
Intraoperative mean arterial blood pressure recordings of 152,445 adult patients undergoing noncardiac surgery were analyzed for periods of time accumulated below each one of the 31 thresholds between 75 and 45 mm Hg (hypotensive exposure times). In a development cohort of 35,904 patients, the associations were sought between each of these 31 cumulative hypotensive exposure times and 30-day postsurgical mortality. On the basis of covariable-adjusted percentage increases in the odds of mortality per minute elapsed of hypotensive exposure time, certain sets of exposure time limits were calculated that portended certain percentage increases in the odds of mortality. A novel risk-scoring method was conceived by counting the number of exposure time limits that had been exceeded within each respective set, one of them being called the SLUScore. The validity of this new method in identifying patients at increased risk was tested in a multicenter validation cohort consisting of 116,541 patients from Cleveland Clinic, Vanderbilt and Saint Louis Universities. Data were expressed as 95% confidence interval, P < .05 considered significant.
Progressively greater hypotensive exposures were associated with greater 30-day mortality. In the development cohort, covariable-adjusted (age, Charlson score, case duration, history of hypertension) exposure limits were identified for time accumulated below each of the thresholds that portended certain identical (5%-50%) percentage expected increases in the odds of mortality. These exposure time limit sets were shorter in patients with a history of hypertension. A novel risk score, the SLUScore (range 0-31), was conceived as the number of exposure limits exceeded for one of these sets (20% set). A SLUScore > 0 (average 13.8) was found in 40% of patients who had twice the mortality, adjusted odds increasing by 5% per limit exceeded. When tested in the validation cohort, a SLUScore > 0 (average 14.1) identified 35% of patients who had twice the mortality, each incremental limit exceeded portending a 5% compounding increase in adjusted odds of mortality, independent of age and Charlson score (C = 0.73, 0.72-0.74, P < .05).
The SLUScore represents a novel method for identifying nearly 1 in every 3 patients experiencing greater 30-day mortality portended by more severe intraoperative hypotensive exposures.
How best to characterize intraoperative hypotension remains unclear. Thus, the authors assessed the relationship between myocardial and kidney injury and intraoperative absolute (mean arterial ...pressure MAP) and relative (reduction from preoperative pressure) MAP thresholds.
The authors characterized hypotension by the lowest MAP below various absolute and relative thresholds for cumulative 1, 3, 5, or 10 min and also time-weighted average below various absolute or relative MAP thresholds. The authors modeled each relationship using logistic regression. The authors further evaluated whether the relationships between intraoperative hypotension and either myocardial or kidney injury depended on baseline MAP. Finally, the authors compared the strength of associations between absolute and relative thresholds on myocardial and kidney injury using C statistics.
MAP below absolute thresholds of 65 mmHg or relative thresholds of 20% were progressively related to both myocardial and kidney injury. At any given threshold, prolonged exposure was associated with increased odds. There were no clinically important interactions between preoperative blood pressures and the relationship between hypotension and myocardial or kidney injury at intraoperative mean arterial blood pressures less than 65 mmHg. Absolute and relative thresholds had comparable ability to discriminate patients with myocardial or kidney injury from those without.
The associations based on relative thresholds were no stronger than those based on absolute thresholds. Furthermore, there was no clinically important interaction with preoperative pressure. Anesthetic management can thus be based on intraoperative pressures without regard to preoperative pressure.
MINI: The objective of this study was to evaluate the accuracy and reliability of pedicle screw placement using O-Arm at dosages below the manufactured recommended dose. O-Arm at reduced dose showed ...a 90% accuracy when compared with computed tomography; however, about 30% medial breaches were misclassified.
Cadaveric study.
The objective was to evaluate O-Arm's ability at low-dose (LD) settings to assess intraoperative screw placement.
Accurate placement of pedicle screws is crucial because of proximity to vital structures. Malposition of screws may result in significant morbidity and potential mortality. O-arm provides real-time, intraoperative imaging of patient's anatomy and provides higher accuracy in scoliosis surgeries, avoiding risk to vital structures. We hypothesize using LD or ultra-low doses (ULDs) to obtain intraoperative images allow for accurate assessment of screw placement, both minimizing radiation exposure and preventing screw misplacement.
Eight cadavers were instrumented with pedicle screws bilaterally from T1 to S1. Screws were randomly placed using O-arm navigation into three positions: contained within the bone, OUT-anterior/lateral, and OUT-medial. O-arm images were obtained at three dosage settings: LD (kVp120/mAs125-lowest manufacturer recommended), very-low dose (VLD) (kVp120/mAs63), and ULD (kVp120/mAs39). Computed tomography (CT) scan was performed using institution's LD protocol (kVp100/mAs50) and gross dissection to identify screw positions.
LD, VLD, ULD, and CT for identifying "IN" screws relative to gross dissection had, a mean (standard deviation) sensitivity of 84.2% (±5.7), specificity of 76.1% (±9.3), and accuracy of 79.9% (±3.1) from all three observers. Across the three observers, the interobserver agreement was 0.67 (0.61-0.72) for LD, 0.74 (0.69-0.79) for VLD, 0.61 (0.56-0.66) for ULD, and 0.79 (0.74-0.84) for CT. Effective doses of radiation (mSV) for LD O-arm scan was 2.16, VLD 1.08, ULD 0.68, and our LD CT protocol was 1.05.
Accuracy of pedicle screw placement is similar for O-arm at all doses and CT compared to gross dissection. Interobserver reliability was substantial for VLD and CT. Approximately 30% of medial screw breaches are, however, misclassified. ULD and VLDs can be used for intraoperative navigation and evaluation purposes within these limitations.
N/A.
Although the package insert clearly states that "the safety and efficacy of sugammadex in pediatric patients have not been established," we hypothesized that sugammadex is used widely in pediatric ...anesthetic practice supplanting neostigmine as the primary drug for antagonizing neuromuscular blockade (NMB). Additionally, we sought to identify the determinants by which pediatric anesthesiologists choose reversal agents and if and how they assess NMB in their practice. Finally, because of sugammadex's effects on hormonal contraception, we sought to determine whether pediatric anesthesiologists counseled postmenarchal patients on the need for additional or alternative forms of contraception and the risk of unintended pregnancy in the perioperative period.
We e-mailed a questionnaire to all 3245 members of the Society of Pediatric Anesthesia (SPA) requesting demographic data and attitudes regarding use of NMB agents, monitoring, and antagonism practices. To address low initial response rates and quantify nonresponse bias, we sent a shortened follow-up survey to a randomly selected subsample (n = 75) of SPA members who did not initially respond. Response differences between the 2 cohorts were determined.
Initial questionnaire response rate was 13% (419 of 3245). Overall, 163 respondents (38.9%; 95% confidence interval CI, 34.2-43.8) used sugammadex as their primary reversal agent, and 106 (25.2%; 95% CI, 21.2-30.0) used it exclusively. Respondents with ≤5 years of practice used sugammadex as their primary reversal agent more often than those with ≥6 years of practice (odds ratio OR: 2.08; 95% CI, 1.31-3.31; P = .001). This increased utilization remained after controlling for institutional restriction and practice type (adjusted OR aOR: 2.20; 95% CI, 1.38-3.54; P = .001). Only 40% of practitioners always assess NMB (train-of-four), and use was inversely correlated with years of practice (Spearman ρ = -0.11, P = .04). Anesthesiologists who primarily used sugammadex assess NMB less routinely (OR: 0.56; 95% CI, 0.34-0.90; P = .01). A slim majority (52.8%) used sugammadex for pediatric postmenarchal girls; those with less experience used it more commonly (P < .001). Thirty-eight percent did not discuss its effects on hormonal contraception with the patient and/or family, independent of anesthesiologist experience (P = .33) and practice location (P = .38). No significant differences were seen in demographics or practice responses between initial and follow-up survey respondents.
Sugammadex is commonly used in pediatric anesthesia, particularly among anesthesiologists with fewer years of practice. Failure to warn postmenarchal adolescents of its consequences may result in unintended pregnancies. Finally, pediatric anesthesia training programs should emphasize objective monitoring of NMB, particularly with sugammadex use.
Continuous monitoring of arterial pressure is important in severely obese patients who are at particular risk for cardiovascular complications. Innovative technologies for continuous noninvasive ...arterial pressure monitoring are now available. In this study, we compared noninvasive arterial pressure measurements using the vascular unloading technique (Clearsight system; Edwards Lifesciences Corp, Irvine, CA) with invasive arterial pressure measurements (radial arterial catheter) in severely obese patients during laparoscopic bariatric surgery.
In 35 severely obese patients (median body mass index, 47 kg/m2), we simultaneously recorded noninvasive and invasive arterial pressure measurements over a period of 45 minutes. We compared noninvasive (test method) and invasive (reference method) arterial pressure measurements (sampling rate 1 Hz = 1/s) using Bland-Altman analysis (accounting for multiple measurements per subject), 4-quadrant plot/concordance analysis (2-minute interval, 5 mm Hg exclusion zone), and error grid analysis (calculating the proportions of measurements in risk zones A-E with A indicating no risk, B low risk, C moderate risk, D significant risk, and E dangerous risk for the patient due to the risk of wrong clinical interventions because of measurement errors).
We observed a mean of the differences (±SD, 95% limits of agreement) between the noninvasively and invasively assessed arterial pressure values of 1.1 mm Hg (±7.4 mm Hg, -13.5 to 15.6 mm Hg) for mean arterial pressure (MAP), 6.8 mm Hg (±10.3 mm Hg, -14.4 to 27.9 mm Hg) for systolic arterial pressure, and 0.8 mm Hg (±6.9 mm Hg, -12.9 to 14.4 mm Hg) for diastolic arterial pressure. The 4-quadrant plot concordance rate (ie, the proportion of arterial pressure measurement pairs showing concordant changes to all changes) was 93% (CI, 89%-96%) for MAP, 93% (CI, 89%-97%) for systolic arterial pressure, and 88% (CI, 84%-92%) for diastolic arterial pressure. Error grid analysis showed that the proportions of measurements in risk zones A-E were 89.5%, 10.0%, 0.5%, 0%, and 0% for MAP and 93.7%, 6.0%, 0.3%, 0%, and 0% for systolic arterial pressure, respectively.
During laparoscopic bariatric surgery, the accuracy and precision of the vascular unloading technique (Clearsight system) was good for MAP and diastolic arterial pressure, but only moderate for systolic arterial pressure according to Bland-Altman analysis. The system showed good trending capabilities. In the error grid analysis, >99% of vascular unloading technique-derived arterial pressure measurements were categorized in no- or low-risk zones.
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