Effectiveness of oral versus intravenous tranexamic acid in primary total hip and knee arthroplasty: a randomised, non-inferiority trial.

BACKGROUND: Tranexamic acid (TXA) reduces rates of blood transfusion for total hip arthroplasty (THA) and total knee arthroplasty (TKA). Although the use of oral TXA rather than intravenous (i.v.) TXA might improve safety and reduce cost, it is not clear whether oral administration is as effective. METHODS: This noninferiority trial randomly assigned consecutive patients undergoing primary THA or TKA under neuraxial anaesthesia to either one preoperative dose of oral TXA or one preoperative dose of i.v. TXA. The primary outcome was calculated blood loss on postoperative day 1. Secondary outcomes were transfusions and complications within 30 days of surgery. RESULTS: Four hundred participants were randomised (200 THA and 200 TKA). The final analysis included 196 THA patients (98 oral, 98 i.v.) and 191 TKA patients (93 oral, 98 i.v.). Oral TXA was non-inferior to i.v. TXA in terms of calculated blood loss for both THA (effect size=-18.2 ml; 95% confidence interval [CI], -113 to 76.3; P<0.001) and TKA (effect size=-79.7 ml; 95% CI, -178.9 to 19.6; P<0.001). One patient in the i.v. TXA group received a postoperative transfusion. Complication rates were similar between the two groups (5/191 [2.6%] oral vs 5/196 [2.6%] i.v.; P=1.00). CONCLUSIONS: Oral TXA can be administered in the preoperative setting before THA or TKA and performs similarly to i.v. TXA with respect to blood loss and transfusion rates. Switching from i.v. to oral TXA in this setting has the potential to improve patient safety and decrease costs.

The Use of Critical Care Services After Orthopedic Surgery at a High-Volume Orthopedic Medical Center: A Retrospective Study.

Background: With an aging population, orthopedics has become one of the largest and fastest growing surgical fields. However, data on the use of critical care services (CCS) in patients undergoing orthopedic procedures remain sparse. Purpose: We sought to elucidate the prevalence and characteristics of patients requiring CCS and intermediate levels of care after orthopedic surgeries at a high-volume orthopedic medical center. Methods: We retrospectively reviewed inpatient electronic medical record data (2016-2020) at a high-volume orthopedic hospital. Patients who required CCS and intermediate levels of care, including step-down unit (SDU) and telemetry services, were identified. We described characteristics related to patients, procedures, and outcomes, including type of advanced services required and surgery type. Results: Of the 50,387 patients who underwent orthopedic inpatient surgery, 1.6% required CCS and 21.6% were admitted to an SDU. Additionally, 482 (1.0%) patients required postoperative mechanical ventilation and 3602 (7.1%) patients required continuous positive airway pressure therapy. Spine surgery patients were the most likely to require any form of advanced care (45.7%). Conclusions: This retrospective review found that approximately one-fourth of orthopedic surgery patients were admitted to units that provided critical and intermediate levels of care. These results may prove useful to hospitals in estimating needs and allocating resources for advanced and critical care services after orthopedic surgery.

Interscalene Brachial Plexus Block with Liposomal Bupivacaine versus Standard Bupivacaine with Perineural Dexamethasone: A Noninferiority Trial.

BACKGROUND: The interscalene nerve block provides analgesia for shoulder surgery. To extend block duration, provide adequate analgesia, and minimize opioid consumption, the use of adjuvants such as dexamethasone as well as the application of perineural liposomal bupivacaine have been proposed. This randomized, double-blinded, noninferiority trial hypothesized that perineural liposomal bupivacaine is noninferior to standard bupivacaine with perineural dexamethasone in respect to average pain scores in the first 72 h after surgery. METHODS: A total of 112 patients undergoing ambulatory shoulder surgery were randomized into two groups. The liposomal bupivacaine group received a 15-ml premixed admixture of 10 ml of 133 mg liposomal bupivacaine and 5 ml of 0.5% bupivacaine (n = 55), while the bupivacaine with dexamethasone group received an admixture of 15 ml of 0.5% standard bupivacaine with 4 mg dexamethasone (n = 56), respectively. The primary outcome was the average numerical rating scale pain scores at rest over 72 h. The mean difference between the two groups was compared against a noninferiority margin of 1.3. Secondary outcomes were analgesic block duration, motor and sensory resolution, opioid consumption, numerical rating scale pain scores at rest and movement on postoperative days 1 to 4 and again on postoperative day 7, patient satisfaction, readiness for postanesthesia care unit discharge, and adverse events. RESULTS: A liposomal bupivacaine group average numerical rating scale pain score over 72 h was not inferior to the bupivacaine with dexamethasone group (mean [SD], 2.4 [1.9] vs. 3.4 [1.9]; mean difference [95% CI], -1.1 [-1.8, -0.4]; P < 0.001 for noninferiority). There was no significant difference in duration of analgesia between the groups (26 [20, 42] h vs. 27 [20, 39] h; P = 0.851). Motor and sensory resolutions were similar in both groups: 27 (21, 48) h versus 27 (19, 40) h (P = 0.436) and 27 [21, 44] h versus 31 (20, 42) h (P = 0.862), respectively. There was no difference in opioid consumption, readiness for postanesthesia care unit discharge, or adverse events. CONCLUSIONS: Interscalene nerve blocks with perineural liposomal bupivacaine provided effective analgesia similar to the perineural standard bupivacaine with dexamethasone. The results show that bupivacaine with dexamethasone can be used interchangeably with liposomal bupivacaine for analgesia after shoulder surgery.

Cerebral Oxygenation in the Sitting Position Is Not Compromised During Spontaneous or Positive-Pressure Ventilation.

BACKGROUND: General anesthesia with neuromuscular blockade may facilitate total shoulder arthroplasty but appears to increase risk of cerebral oxygen desaturation. Cerebral desaturation is undesirable and is a proxy for risk of stroke. PURPOSES/QUESTIONS: This study tested the hypothesis that cerebral oxygen desaturation occurs frequently during general anesthesia with neuromuscular blockade and positive-pressure ventilation but does not occur with spontaneous ventilation. Correlations were sought among cerebral oxygen saturation, blood pressure, and cardiac index. METHODS: We designed a prospective, observational, cohort study to measure cerebral oxygenation in 25 patients during general anesthesia, both with and without positive-pressure ventilation. Patients undergoing elective shoulder arthroplasty in the sitting position received an arterial catheter, near-infrared spectroscopic measurement of cerebral oxygenation, and non-invasive cardiac output measurement. Moderate hypotension was allowed. Blood pressure was supported as needed with ephedrine or low-dose epinephrine (but avoiding phenylephrine). Hypercapnia (45 to 55 mmHg) was targeted during positive-pressure ventilation. RESULTS: No cerebral oxygen desaturations occurred, regardless of ventilation mode. Under positive-pressure ventilation, the median (interquartile range: Q1, Q3) cerebral oxygenation was 110% of baseline (104, 113), the mean arterial pressure was 62% of baseline (59, 69), and the cardiac index was 82% of baseline (71, 104). Cerebral oxygenation did not correlate with blood pressure or cardiac index but had moderate correlation with end-tidal carbon dioxide. No strokes occurred. CONCLUSIONS: There were no signs of inadequate brain perfusion during general anesthesia using paralytic agents. Positive-pressure ventilation with moderate hypotension in the sitting position does not endanger patients, in the context of moderate hypercapnia and hemodynamic support using ephedrine or epinephrine.

Evaluation of Postgraduates Following Implementation of a Focus Assessed Transthoracic Echocardiography (FATE) Training Course-A Pilot Study.

At our institution, implementation of a formal training course in Basic Focus Assessed Transthoracic Echocardiography (FATE) was associated with an improvement in anesthesia trainees' ability to obtain transthoracic echocardiography (TTE) images. Total image acquisition scores improved by a median (Q1, Q3) 9.1 (2.9,14.7) percentage points from pre-to post-hands-on FATE course (n=20; p=0.001). Participants who returned for a subsequent assessment 5 months following the course demonstrated a median (Q1, Q3) 18.0 (9.1,22.1) percentage point improvement from their pre-course total image acquisition scores (n=11; p=0.002). This pilot study established the feasibility of our program and results suggest that the basic FATE course can be used to teach trainees TTE quickly, effectively, and with significant retention.

Aortic perforation during lateral lumbar interbody fusion.

STUDY DESIGN: A case report. OBJECTIVE: To report a unique case of aortic perforation during lateral lumbar interbody fusion (LLIF). SUMMARY OF BACKGROUND DATA: Among the reported advantages of this minimally invasive transpsoas procedure is the avoidance of an anterior intraperitoneal approach to the lumbar spine, thus avoiding visceral and vascular injuries typically associated with the latter. METHODS: We report a single case of aortic perforation during LLIF, which occurred in the setting of an incidental endplate and anterior vertebral cortex violation. RESULTS: During the implantation of an interbody prosthetic device at the L3-L4 level, the proximal aspect of the implant broke which caused cage misplacement. During the attempt to advance the well-fixed cage, distal violation of the endplate and anterior cortex of the L3 vertebra was noted, concomitant with immediate loss of blood pressure. A presumptive diagnosis of injury to a major vascular structure was quickly made, along with the decision to proceed with emergency laparotomy to repair a through-and-through laceration of the aortic terminus. After successful suture repair of the aortic lesions, the patient was kept intubated, and transferred to the intensive care unit in stable condition. CONCLUSIONS: The distal endplate and anterior vertebral cortex violation can result in the formation of an anterior bony spur in close proximity to the major abdominal vascular structures, and despite the avoidance of an anterior approach to the lumbar spine, surgery-related injury to major abdominal vessels can occur during LLIF. Aortic perforation is a rare, yet potentially lethal intraoperative complication of LLIF, which requires emergency laparatomy and vascular suture repair.

Transesophageal echocardiography during cardiac arrest in orthopedic surgery patients: a report of two cases and a review of the literature.

BACKGROUND: Cardiac arrest situations represent an enormous clinical challenge to the physicians involved. Research suggests that the utilization on transesophageal echocardiography (TEE) may provide important diagnostic information and allows for institution of more specific treatment, while not hampering resuscitation efforts. CASE DESCRIPTION: In this review, we highlight the usefulness of TEE in cardiac arrest situations in the orthopedic setting, by presenting two perioperative cases. In one case, TEE was used to diagnose intraoperative pulmonary embolism and guide thrombolytic therapy. The second case highlights the use of TEE in management of hemodynamic instability in a patient with aortic stenosis. LITERATURE REVIEW: Memtsoudis et al. showed that in 19 of 22 cardiac arrests, an underlying pathological process could be established with TEE, leading to specific interventions beyond the institution of advanced cardiac life support measures. CLINICAL RELEVANCE: TEE can provide rapid diagnostic information guiding treatment in patients with hemodynamic compromise. The use is expanding beyond the cardiac operating theater and given the potential clinical impact consideration should be given to utilizing this valuable imaging modality in appropriate clinical situation.

Heparin dose response is independent of preoperative antithrombin activity in patients undergoing coronary artery bypass graft surgery using low heparin concentrations.

BACKGROUND: Unfractionated heparin's primary mechanism of action is to enhance the enzymatic activity of antithrombin (AT). We hypothesized that there would be a direct association between preoperative AT activity and both heparin dose response (HDR) and heparin sensitivity index (HSI) in patients undergoing coronary artery bypass graft surgery. METHODS: Demographic and perioperative data were collected from 304 patients undergoing primary coronary artery bypass graft surgery. AT activity was measured after induction of general anesthesia using a colorimetric method (Siemens Healthcare Diagnostics, Tarrytown, NY). Activated coagulation time (ACT), HDR, and HSI were measured using the Hepcon HMS Plus system (Medtronic, Minneapolis, MN). Heparin dose was calculated for a target ACT using measured HDR by the same system. Multivariate linear regression was performed to identify independent predictors of HDR. Subgroup analysis of patients with low AT activity (<80% normal; <0.813 U/mL) who may be at risk for heparin resistance was also performed. RESULTS: Mean baseline ACT was 135 ± 18 seconds. Mean calculated HDR was 98 ± 21 s/U/mL. Mean baseline AT activity was 0.93 ± 0.13 U/mL. Baseline AT activity was not significantly associated with baseline or postheparin ACT, HDR, or HSI. Addition of AT activity to multivariable linear regression models of both HDR and HSI did not significantly improve model performance. Subgroup analysis of 49 patients with baseline AT <80% of normal levels did not reveal a relationship between low AT activity and HDR or HSI. Preoperative AT activity, HDR, and HSI were not associated with cardiac troponin I levels on the first postoperative day, intensive care unit duration, or hospital length of stay. CONCLUSION: Although enhancing AT activity is the primary mechanism by which heparin facilitates cardiopulmonary bypass anticoagulation, low preoperative AT activity is not associated with impaired response to heparin or to clinical outcomes when using target ACTs of 300 to 350 seconds.

3D transesophageal echocardiography: a review of recent literature 2007-2009.

PURPOSE OF REVIEW: The use of two-dimensional (2D) transesophageal echocardiography (TEE) is nearly universal in cardiac surgical operating rooms around the world. Cardiac anesthesiologists or cardiologists perform these examinations, facilitating significant advancements in surgical techniques by the immediacy and accuracy of intra-operative ultrasound imaging. Three-dimensional (3D) TEE capabilities have been available since the 1990s but penetration has been poor. With the advent of real-time 3D TEE, interest in this technology has increased dramatically. This is a comprehensive review of English language publications in the field from 2007 to 2009. RECENT FINDINGS: This review utilized Pubmed databases, with search strategy based on primary key words: 3D echocardiography, transesophageal echocardiography, cardiac surgery, and/or cardiopulmonary bypass. Three major areas of clinical practice are impacted by the findings of these studies: cardiac valve repair and replacement, assessment of ventricular function, and image guidance for percutaneous procedures. SUMMARY: The review resulted in the conclusion that 3D TEE provides unique and dynamic 3D spatial information that cannot be obtained by 2D TEE or fluoroscopy. In addition to technical and process advancements, future studies should address educational value in terms of acceleration of learning curves, and impact on surgical decision making.

Heparin concentration-based anticoagulation for cardiac surgery fails to reliably predict heparin bolus dose requirements.

BACKGROUND: Hemostasis management has evolved to include sophisticated point-of-care systems that provide individualized dosing through heparin concentration-based anticoagulation. The Hepcon HMS Plus system (Medtronic, Minneapolis, MN) estimates heparin dose, activated clotting time (ACT), and heparin dose response (HDR). However, the accuracy of this test has not been systematically evaluated in large cohorts. METHODS: We examined institutional databases for all patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) at our institution from February 2005 to July 2008. During this period, the Hepcon HMS Plus was used exclusively for assessment of heparin dosing and coagulation monitoring. Detailed demographic, surgical, laboratory, and heparin dosing data were recorded. ACT, calculated and measured HDR, and heparin concentrations were recorded. Performance of the Hepcon HMS Plus was assessed by comparison of actual and target ACT values and calculated and measured HDR. RESULTS: In 3880 patients undergoing cardiac surgery, heparin bolus dosing to a target ACT resulted in wide variation in the postheparin ACT (r(2) = 0.03). The postheparin ACT did not reach the target ACT threshold in 7.4%(i.e., when target ACT was 300 s) and 16.9% (i.e., when target ACT was 350 s) of patients. Similarly, the target heparin level calculated from the HDR did not correlate with the postbolus heparin level, with 18.5% of samples differing by more than 2 levels of the assay. Calculated and measured HDR were not linearly related at any heparin level. CONCLUSIONS: The Hepcon HMS Plus system poorly estimates heparin bolus requirements in the pre-CPB period. Further prospective studies are needed to elucidate what constitutes adequate anticoagulation for CPB and how clinicians can reliably and practically assess anticoagulation in the operating room.

Postoperative activity, but not preoperative activity, of antithrombin is associated with major adverse cardiac events after coronary artery bypass graft surgery.

BACKGROUND: Low levels of antithrombin (AT) have been independently associated with prolonged intensive care unit stay and an increased incidence of neurologic and thromboembolic events after cardiac surgery. We hypothesized that perioperative AT activity is independently associated with postoperative major adverse cardiac events (MACEs) in patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: We prospectively studied 1403 patients undergoing primary CABG surgery with cardiopulmonary bypass (CPB) (http://clinicaltrials.gov/show/NCT00281164). The primary clinical end point was occurrence of MACE, defined as a composite outcome of any one or more of the following: postoperative death, reoperation for coronary graft occlusion, myocardial infarction, stroke, pulmonary embolism, or cardiac arrest until first hospital discharge. Plasma AT activity was measured before surgery, after post-CPB protamine, and on postoperative days (PODs) 1-5. Multivariate logistic regression modeling was performed to estimate the independent effect of perioperative AT activity upon MACE. RESULTS: MACE occurred in 146 patients (10.4%), consisting of postoperative mortality (n = 12), myocardial infarction (n = 108), stroke (n = 17), pulmonary embolism (n = 8), cardiac arrest (n = 16), or a subsequent postoperative or catheter-based treatment for graft occlusion (n = 6). AT activity at baseline did not differ between patients with (0.91 ± 0.13 IU/mL; n = 146) and without (0.92 ± 0.13 IU/mL; n = 1257) (P = 0.18) MACE. AT activity in both groups was markedly reduced immediately after CPB and recovered to baseline values over the ensuing 5 PODs. Postoperative AT activity was significantly lower in patients with MACE than those without MACE. After adjustment for clinical predictors of MACE, AT activity on PODs 2 and 3 was associated with MACE. CONCLUSIONS: Preoperative AT activity is not associated with MACE after CABG surgery. MACE is independently associated with postoperative AT activity but only at time points occurring predominantly after the MACE.