The Effect of Hypotensive Anesthesia on Hemoglobin Levels during Total Knee Arthroplasty.

INTRODUCTION: Hypotensive epidural anesthesia (HEA) is used in total joint arthroplasty as a safe and effective blood-saving modality. In order to maintain the blood pressure and heart rate patients, receive 1000 to 1500 mL of lactated Ringer's solution during surgery. While HEA reduces the intraoperative blood loss, the effect of intravenous fluid loading on hemoglobin levels is not fully understood. The current study investigates the effect of HEA on perioperative hemoglobin levels. MATERIALS AND METHODS: The study included 35 patients operated on by a single surgeon undergoing primary total knee arthroplasty under HEA. Intraoperatively, at least 300 mL of intravenous fluid were given every 15 min over the first 60 min after HEA. Blood samples were drawn before entering the operating room, after HEA, as well as after inflation of the tourniquet, every 15 min thereafter, as well as in the recovery room and on postoperative days one and two. In addition, fluid in- and outtake was recorded. RESULTS: Patients received a mean 1275 mL during the 60 min of tourniquet time. The mean arterial pressure (MAP) 5 min after HEA dropped to 60 mmHg and reached a constant level of around 58 mmHg 15 min after HEA. The average hemoglobin level dropped from 13.9 g/dL prior to HEA, to 12.5 g/dL immediately after HEA (p < 0.001). Intraoperatively the hemoglobin level dropped further and reached 11.8 g/dL at 60 min in the absence of blood loss. CONCLUSIONS: Hypotensive epidural anesthesia and the resulting fluid substitution resulted in an average hemoglobin drop of 2.1 g/dL within the first 60 min. This needs to be taken into account when evaluating the need for blood transfusions after primary joint replacement surgery under HEA.

Multimodal prophylaxis in patients with a history of venous thromboembolism undergoing primary elective hip arthroplasty.

AIMS: We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient's risk of VTE. METHODS: Between 2004 to 2018, 257 patients with a proven history of VTE underwent 277 primary elective THA procedures by two surgeons at a single institution. The patients had a history of deep vein thrombosis (DVT) (186, 67%), pulmonary embolism (PE) (43, 15.5%), or both (48, 17.5%). Chemoprophylaxis included aspirin (38 patients), anticoagulation (215 patients), or a combination of aspirin and anticoagulation (24 patients). A total of 50 patients (18%) had a vena cava filter in situ at the time of surgery. Patients were followed for 120 days to record complications, and for one year to record mortality. RESULTS: Postoperative VTE was diagnosed in seven patients (2.5%): DVT in five, and PE with and without DVT in one patient each. After hospitalization, three patients required readmiss-ion for evacuation of a haematoma, one for wound drainage, and one for monitoring of an elevated international normalized ratio (INR). Seven patients died (2.5%). One patient died five months postoperatively of a PE during open thrombectomy. She had discontinued anticoagulation. One patient died of a haemorrhagic stroke while receiving Coumadin. PE or bleeding was not suspected in the remaining five fatalities. CONCLUSION: Multimodal prophylaxis is safe and effective in patients with a history of VTE. Postoperative anticoagulation should be prudent as very few patients developed VTE (2.5%) or died of suspected or confirmed PE. Mortality during the first year was mostly unrelated to either VTE or bleeding. Cite this article: Bone Joint J 2020;102-B(7 Supple B):71-77.

Anaesthetic care of patients undergoing primary hip and knee arthroplasty: consensus recommendations from the International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) based on a systematic review and meta-analysis.

BACKGROUND: Evidence-based international expert consensus regarding anaesthetic practice in hip/knee arthroplasty surgery is needed for improved healthcare outcomes. METHODS: The International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) systematic review, including randomised controlled and observational studies comparing neuraxial to general anaesthesia regarding major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, genitourinary, thromboembolic, neurological, infectious, and bleeding complications. Medline, PubMed, Embase, and Cochrane Library including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, from 1946 to May 17, 2018 were queried. Meta-analysis and Grading of Recommendations Assessment, Development and Evaluation approach was utilised to assess evidence quality and to develop recommendations. RESULTS: The analysis of 94 studies revealed that neuraxial anaesthesia was associated with lower odds or no difference in virtually all reported complications, except for urinary retention. Excerpt of complications for neuraxial vs general anaesthesia in hip/knee arthroplasty, respectively: mortality odds ratio (OR): 0.67, 95% confidence interval (CI): 0.57-0.80/OR: 0.83, 95% CI: 0.60-1.15; pulmonary OR: 0.65, 95% CI: 0.52-0.80/OR: 0.69, 95% CI: 0.58-0.81; acute renal failure OR: 0.69, 95% CI: 0.59-0.81/OR: 0.73, 95% CI: 0.65-0.82; deep venous thrombosis OR: 0.52, 95% CI: 0.42-0.65/OR: 0.77, 95% CI: 0.64-0.93; infections OR: 0.73, 95% CI: 0.67-0.79/OR: 0.80, 95% CI: 0.76-0.85; and blood transfusion OR: 0.85, 95% CI: 0.82-0.89/OR: 0.84, 95% CI: 0.82-0.87. CONCLUSIONS: Recommendation: primary neuraxial anaesthesia is preferred for knee arthroplasty, given several positive postoperative outcome benefits; evidence level: low, weak recommendation. RECOMMENDATION: neuraxial anaesthesia is recommended for hip arthroplasty given associated outcome benefits; evidence level: moderate-low, strong recommendation. Based on current evidence, the consensus group recommends neuraxial over general anaesthesia for hip/knee arthroplasty. TRIAL REGISTRY NUMBER: PROSPERO CRD42018099935.

Changes in the augmentation index and postoperative orthostatic intolerance in orthopedic surgery: a prospective cohort study.

BACKGROUND: Postoperative orthostatic intolerance (OI) can be a major obstacle to early ambulation and its determinants are poorly understood. We aimed to study postoperative changes in vascular tone and their potential association with OI in various orthopedic surgical settings. METHODS: In this prospective cohort study, 350 patients undergoing total joint arthroplasty under neuraxial anesthesia or spine surgery under general anesthesia were enrolled. We determined the augmentation index (AI) as a measure of vascular tone and studied symptoms of OI using a validated questionnaire at various postoperative time points. RESULTS: The AI was significantly reduced postoperatively (at spinal resolution in patients with neuraxial anesthesia or two hours postoperatively in general anesthesia) compared with baseline values in all procedures and did not subsequently return to baseline throughout the postoperative period in the majority of patients [252/335 (75.2%); P < 0.001]. The majority [260/342 (76.0%); P < 0.001] of patients had postoperative symptoms of OI. Nevertheless, no association was found between postoperative change in AI from baseline and postoperative symptoms of OI. CONCLUSIONS: A significantly prolonged decrease in AI and symptoms of OI are common after orthopedic surgery. Nevertheless, an association between the two measures was not observed. While compensatory mechanisms may limit the influence of an AI decrease on symptoms of OI, more research is needed to understand the contributing factors and aid in the identification of patients at risk of OI.

Changes in Markers of Thrombin Generation and Interleukin-6 During Unicondylar Knee and Total Knee Arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is associated with a risk of thromboembolism requiring routine thromboprophylaxis, but there is debate about the risk with unicondylar knee arthroplasty (UKA) as it is a more minor procedure. We sought to investigate the relative risk of thromboembolism with UKA compared to TKA and one-staged bilateral TKA (BTKA) by measuring the increase in circulating biochemical markers of thrombin generation during the procedures. Degree of surgical trauma was also assessed by measuring interleukin-6, a marker of metabolic injury. METHODS: We prospectively studied a total of 75 patients: 25 patients undergoing UKA, unilateral TKA, and BTKA, respectively. All patients had surgery performed with tourniquet and received no tranexamic acid. Blood samples were taken during surgery and assayed for circulating markers of thrombin generation: prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin complexes plus interleukin-6. RESULTS: Thrombin-antithrombin complexes, increased during all time points (P < .001) but was not significantly different between surgical treatment groups. F1+2 also rose significantly during surgery, with no significant difference between UKA and TKA. There was, however, a significant difference in F1+2 between BTKA and UKA or TKA (P < .02). Interleukin-6 rose minimally with UKA but rose significantly with TKA and BTKA (P < .001). CONCLUSION: Based on these data of circulating biochemical markers, patients undergoing UKA are at similar risk of thromboembolism with respect to TKA despite a lower index of metabolic injury. We believe that UKA patients should receive thromboprophylaxis comparable to TKA patients.

The Clinical Severity of Patients Diagnosed With an In-Hospital Pulmonary Embolism Following Modern, Elective Joint Arthroplasty Is Unrelated to the Location of Emboli in the Pulmonary Vasculature.

BACKGROUND: In the event of a postoperative pulmonary embolism (PE), it is generally believed that patients with centrally located emboli will have worse clinical symptoms than those with segmental or subsegmental ones. We studied if a relationship exists between the clinical severity at the time of PE diagnosis and the location of the emboli within the pulmonary vasculature. METHODS: All 269 patients who developed an in-hospital, computed tomography pulmonary angiography-proved, PE following elective total hip arthroplasty or total knee arthroplasty in our institution were studied. The clinical severity of the PE was calculated using the Pulmonary Embolism Severity Index (PESI) that classifies patients in 5 classes (class 5: most severe). All computed tomography pulmonary angiographies were re-reviewed to determine the location of the emboli within the pulmonary vasculature (central, segmental, or subsegmental-unilateral or bilateral). The association between PESI and the PE location was examined. RESULTS: The most proximal location of the emboli was central in 62, segmental in 139, and subsegmental in 68. There were 180 unilateral and 89 bilateral PE patients. There was no association between the PESI and the location of the emboli within the pulmonary vasculature (P = .32). Patients with bilateral or unilateral lung involvement had similar PESI (P = .78). CONCLUSION: The PESI, a recognized, validated predictor of mortality after PE was similar in patients with central, segmental, or subsegmental PE; and in patients with unilateral or bilateral lung involvement. The present study may aid clinicians while assessing and discussing the severity of PE symptoms with patients at the time of diagnosis.

An Observational Study of Cerebral Blood Flow Velocity During Hypotensive Epidural Anesthesia.

BACKGROUND: Hypotensive epidural anesthesia (HEA), as practiced at our institution, uses sympathetic blockade to achieve mean arterial blood pressure (MAP) of ≤50 mm Hg while administering epinephrine by infusion to support the circulation. HEA has not been associated with gross adverse effects on neurologic outcome or cognitive function in the postoperative period, suggesting adequate cerebral blood flow (CBF). However, the use of MAPs well below the commonly accepted lower limit of CBF autoregulation suggests that CBF should be significantly reduced below normal levels. To examine these conflicting hypotheses, we performed a prospective investigation of the effects of HEA on CBF velocity (CBFV), an accepted index of cerebral perfusion. METHODS: Fifty-two hip replacement patients were studied. HEA was induced by lumbar epidural injection of local anesthetic and infusion of epinephrine to achieve an MAP of ≤50 mm Hg. Propofol/midazolam sedation was administered. Baseline CBFV was recorded pre-HEA (after sedation and before local anesthetic injection) and continuously thereafter. RESULTS: During HEA, MAP decreased by 40% and was stable throughout. The CBFVmean at baseline and at 3 HEA intervals during surgery was 46 ± 12 (SD), 45 ± 12, 47 ± 14, and 47 ± 14 cm·s, respectively. Although mean CBFVmean did not vary, there was considerable heterogeneity among patients. Twelve patients (23%) experienced reductions of CBFVmean of >20% during HEA intervals (99% lower confidence limit: 9%) and 6 (12%) reductions of >30% (99% lower confidence limit: 1%). There was no correlation between CBFVmean and MAP for MAPs between 100 and 40 mm Hg (R = 0.0015, P = 0.44). There were no instances of gross postoperative neurologic injury. CONCLUSIONS: Both hypotheses proved partially correct. CBFV was sometimes well maintained during HEA, despite MAPs well below the commonly accepted lower limit of autoregulation. However, there was considerable interindividual heterogeneity with 23% of subjects having CBFV reductions >20% (99% lower confidence limit: 9%), with some reductions approaching the threshold for ischemic injury. The present data do not allow us to determine whether hypotension would be similarly tolerated in other circumstances.

Lateralizing epidural catheter placement as evidenced by electrical stimulation.

BACKGROUND: Epidural steroids are more effective if administered in the anterolateral epidural space. It follows that the ability to administer local anesthetics in the ipsilateral anterolateral epidural space should likewise improve their efficacy for postoperative epidural analgesia. QUESTIONS/PURPOSES: We determined whether epidural catheters can be reliably placed in the ipsilateral anterolateral epidural space using the paramedian approach. Motor responses elicited by electrical stimulation were used to identify lateralization. We further assessed what angle of needle insertion resulted in successful catheter placement. METHODS: Epidural anesthesia was performed in 68 patients undergoing total joint arthroplasty using the paramedian approach. FDA-approved electrical stimulating catheters were utilized, and the muscle response elicited was recorded with each centimeter of advancement of the catheter. Digital photographs were taken to determine the angle of needle entry. RESULTS: Using the paramedian approach, an ipsilateral twitch was noted in 66 of the 68 patients (two had no response). With advancement of the catheter (2-5 cm), the twitch remained ipsilateral in 56 but disappeared in 12. The mean angle of the epidural needle was 40° to the midline. All patients had successful epidural anesthesia as evidenced by no response to surgical incision. CONCLUSIONS: Epidural catheters can be reliably placed onto the side of surgery using the paramedian approach. This provides the opportunity to more selectively administer epidural local anesthetics. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Perioperative comparative effectiveness of anesthetic technique in orthopedic patients.

BACKGROUND: The impact of anesthetic technique on perioperative outcomes remains controversial. We studied a large national sample of primary joint arthroplasty recipients and hypothesized that neuraxial anesthesia favorably influences perioperative outcomes. METHODS: Data from approximately 400 hospitals between 2006 and 2010 were accessed. Patients who underwent primary hip or knee arthroplasty were identified and subgrouped by anesthesia technique: general, neuraxial, and combined neuraxial-general. Demographics, postoperative complications, 30-day mortality, length of stay, and patient cost were analyzed and compared. Multivariable analyses were conducted to identify the independent impact of choice of anesthetic on outcomes. RESULTS: Of 528,495 entries of patients undergoing primary hip or knee arthroplasty, information on anesthesia type was available for 382,236 (71.4%) records. Eleven percent were performed under neuraxial, 14.2% under combined neuraxial-general, and 74.8% under general anesthesia. Average age and comorbidity burden differed modestly between groups. When neuraxial anesthesia was used, 30-day mortality was significantly lower (0.10, 0.10, and 0.18%; P < 0.001), as was the incidence of prolonged (>75th percentile) length of stay, increased cost, and in-hospital complications. In the multivariable regression, neuraxial anesthesia was associated with the most favorable complication risk profile. Thirty-day mortality remained significantly higher in the general compared with the neuraxial or neuraxial-general group for total knee arthroplasty (adjusted odds ratio [OR] of 1.83, 95% CI 1.08-3.1, P = 0.02; OR of 1.70, 95% CI 1.06-2.74, P = 0.02, respectively). CONCLUSIONS: The utilization of neuraxial versus general anesthesia for primary joint arthroplasty is associated with superior perioperative outcomes. More research is needed to study potential mechanisms for these findings.

Pulmonary circulatory changes after bilateral total knee arthroplasty during regional anesthesia.

STUDY OBJECTIVE: To monitor the pulmonary hemodynamics of patients undergoing bilateral total knee arthroplasty (BTKA) intraoperatively and up to 24 hours following surgery. DESIGN: Prospective observational study. SETTING: University-affiliated teaching hospital. PATIENTS: 30 ASA physical status 2 and 3 patients scheduled for single-stage, cemented BTKA during epidural anesthesia. INTERVENTIONS: Pulmonary artery catheters were in all patients. MEASUREMENTS: Systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), the ratio of PVR to SVR at baseline, at the beginning of surgery, and after each knee implantation were recorded and compared with measurements taken one day postoperatively (POD 1). MAIN RESULTS: On POD 1, PVR/SVR was increased by 30% compared with baseline (P < 0.0001) and by 20% versus the end of surgery (P < 0.0001). Systemic vascular resistance decreased during surgery and was significantly lower than baseline at 24 hours after surgery (P < 0.0001). No significant change in PVR was noted during surgery. CONCLUSION: The PVR/SVR ratio on the day following BTKA was increased. This change may represent the different effects of inflammatory perioperative stresses on the pulmonary and systemic vasculature.

Markers of thrombin generation during resurfacing and noncemented total hip arthroplasty: a pilot study.

BACKGROUND: Hip resurfacing arthroplasty (HRA) could be associated with an increased risk of deep vein thrombosis (DVT) compared to traditional noncemented THA because it involves greater dissection, increased kinking and distortion of the femoral vessels, takes longer to perform, and involves insertion of some cement into the femur. QUESTIONS/PURPOSES: Does HRA lead to greater risk of thromboembolism compared with noncemented THA? METHODS: We prospectively studied 20 patients receiving HRA and 20 receiving THA. All patients were younger than 67 years old and were similar in height, weight, American Society of Anesthesiologists status, and gender mix. Patients undergoing HRA were younger (mean, 50 versus 59 years), their surgery was longer (mean, 87 versus 65 minutes), and they required more crystalloid during surgery (mean, 2160 versus 1662 mL). Radial artery blood samples were taken at six events during surgery and assayed for prothrombin fragment F1 + 2 and thrombin-antithrombin III complex (TAT) using enzyme-linked immunosorbent assays. RESULTS: We observed no differences in the intraoperative increases in F1 + 2 and TAT between the two groups and no differences in surgical events. CONCLUSION: Based on these data, HRA and THA should have similar risk of thromboembolism as THA based on the parameters we measured. LEVEL OF EVIDENCE: Level I, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Perioperative pulmonary circulatory changes during bilateral total hip arthroplasty under regional anesthesia.

BACKGROUND AND OBJECTIVES: The transient and rarely clinically relevant effect of bone and cement embolization during unilateral joint arthroplasty is a known phenomenon. However, available studies do not address events surrounding bilateral total hip arthroplasties, during which embolic load is presumably doubled. To elucidate events surrounding this increasingly used procedure and assess the effect on the pulmonary hemodynamics in the intraoperative and postoperative periods, we studied 24 subjects undergoing cemented bilateral total hip arthroplasty during the same anesthetic session. MATERIALS: Twenty-four patients without previous pulmonary history undergoing cemented bilateral total hip arthroplasty under controlled epidural hypotension were enrolled. Pulmonary artery catheters were inserted and hemodynamic variables were recorded at baseline, 5 mins after the implantation of each hip joint, 1 hr and 1 day after surgery. Mixed venous blood gases and complete blood counts were analyzed at every time point. RESULTS: An increase in pulmonary vascular resistance was observed after the second but not the first hip implantation when compared with values at incision. Pulmonary vascular resistance remained elevated 1 hr after surgery. Pulmonary artery pressures were significantly elevated on postoperative day 1 compared with those at baseline. The white blood cell count increased in response to the second hip implantation but not the first compared with incision. CONCLUSIONS: The embolization of material during bilateral total hip arthroplasty is associated with prolonged increases in pulmonary artery pressures and vascular resistance, particularly after completion of the second side. Performance of bilateral procedures should be cautiously considered in patients with diseases suggesting decreased right ventricular reserve.

Relationship between perioperative urinary tract infection and deep infection after joint arthroplasty.

UNLABELLED: Surgical wound infection is a serious and potentially catastrophic complication after joint arthroplasty. Urinary tract infection is a common infection that creates a potential reservoir of resistant pathogens and increases patient morbidity. We asked whether treated preoperative and postoperative urinary tract infections are risk factors for deep joint infection. We examined the medical records of 19,735 patients. The minimum had joint infections develop. Of these, three had preoperative and four had postoperative urinary tract infections. The majority of bacteria were not enteric. The bacteria in the two types of infections were not identical. Control subjects were randomly selected from a list of patients matched with patients having infections. Of these, eight had preoperative and one had postoperative urinary tract infections. We found no association between the preoperative urinary tract infection (odds ratio, 0.341; 95% confidence interval, 0.086-1.357) or postoperative urinary tract infection (odds ratio, 4.222; 95% confidence interval, 0.457-38.9) and wound infection. Only one of the 58 patients with wound infections had a urinary tract infection with the same bacteria in both infections. Given the infection rate was very low (0.29%), the power of the study was only 25%. Although limited, the data suggest patients with urinary tract infections had no more likelihood of postoperative infection. We believe treated urinary tract infection should not be a reason to delay or postpone surgery. LEVEL OF EVIDENCE: Level III, therapeutic study.

Venous thromboembolic disease after total hip and knee arthroplasty: current perspectives in a regulated environment.

Venous thromboembolic disease is the single most common reason for readmission to the hospital following total hip and total knee arthroplasty and remains a genuine threat to the life of the patient. Nevertheless, advances in surgical procedure, anesthetic management, and postoperative convalescence have altered the risks of venous thromboembolism after total joint arthroplasty in the lower extremity. Regional anesthetic techniques reduce the prevalence of venographic thrombosis by approximately 50%, and intraoperative monitoring has identified preparation of the femoral canal as the sentinel event that activates the coagulation cascade by the intravasation of marrow fat into the systemic circulation. Prevention of venographic thrombosis is most efficacious by administering fractionated heparin followed by warfarin; warfarin (international normalized ratio 2.0) appears to have a greater safety margin than fractionated heparin based on clinically meaningful bleeding events. Prevention of readmission events, proximal thrombosis, or pulmonary embolism has been demonstrated by using low-intensity warfarin. Aspirin, when used in conjunction with hypotensive epidural anesthesia after hip arthroplasty and regional anesthesia after knee arthroplasty, combined with pneumatic compression devices, also has been suggested to prevent clinical venous thromboembolism, as measured by readmission events. Oral thrombin inhibitors hold promise, but instances of liver toxicity have precluded approval in North America to date. Mechanical compression devices enhance venous flow and increase fibrinolytic activity in the lower extremity; clinical trials demonstrate efficacy in reducing venographic thrombosis alone after total knee arthroplasty and in combination with other chemoprophylactic agents after total hip arthroplasty. Extended chemoprophylaxis for 3 to 6 weeks after surgery is prudent in view of the protracted risk of thrombogenesis and the late occurrence of readmission for venous thrombosis and pulmonary embolism.

Potent anticoagulants are associated with a higher all-cause mortality rate after hip and knee arthroplasty.

Anticoagulation for thromboprophylaxis after THA and TKA has not been confirmed to diminish all-cause mortality. We determined whether the incidence of all-cause mortality and pulmonary embolism in patients undergoing total joint arthroplasty differs with currently used thromboprophylaxis protocols. We reviewed articles published from 1998 to 2007 that included 6-week or 3-month incidence of all-cause mortality and symptomatic, nonfatal pulmonary embolism. Twenty studies included reported 15,839 patients receiving low-molecular-weight heparin, ximelagatran, fondaparinux, or rivaroxaban (Group A); 7193 receiving regional anesthesia, pneumatic compression, and aspirin (Group B); and 5006 receiving warfarin (Group C). All-cause mortality was higher in Group A than in Group B (0.41% versus 0.19%) and the incidence of clinical nonfatal pulmonary embolus was higher in Group A than in Group B (0.60% versus 0.35%). The incidences of all-cause mortality and nonfatal pulmonary embolism in Group C were similar to those in Group A (0.4 and 0.52, respectively). Clinical pulmonary embolus occurs despite the use of anticoagulants. Group A anticoagulants were associated with the highest all-cause mortality of the three modalities studied.

Hypotensive epidural anesthesia in patients with aortic stenosis undergoing total hip replacement.

BACKGROUND AND OBJECTIVES: The use of conduction anesthesia and induced hypotension are traditionally contraindicated in patients with aortic stenosis. This hypothesis-generating observational pilot study details the clinical outcomes in patients with aortic stenosis undergoing hypotensive epidural anesthesia for total hip replacement. METHODS: From a database of 1,947 consecutive patients undergoing total hip replacement under hypotensive epidural anesthesia performed from 1994 to 2005, 22 patients were identified with aortic stenosis. Chart review was performed. All patients were monitored with central venous pressure and radial arterial catheters. Cardiovascular and renal outcomes, thromboembolic events, and blood loss and transfusion were assessed. RESULTS: Twenty-two patients were identified: 19 patients (86%) were American Society of Anesthesiologists classification III, and 3 patients (14%) were American Society of Anesthesiologists classification IV. The mean age was 75 years (range: 58-92). No patient suffered from preoperative angina, syncope, or resting dyspnea. Valve areas ranged from 0.9 to 1.8 cm(2) and peak gradient from 12 to 64 mm Hg. Systolic blood pressure was maintained at 60 to 100 mm Hg. The mean duration of hypotension was 91 minutes (range: 50-200). Heart rate was maintained at a mean (+/-SD) of 70 +/- 11. Central venous pressure was maintained at baseline value. Mean intraoperative crystalloid administered was 1,695 mL (range: 900-4,000), and mean estimated blood loss was 234 mL (range: 100-1,500). There were no deaths, myocardial infarctions, cerebrovascular accidents, or pulmonary embolic events. No patient developed renal dysfunction. CONCLUSIONS: We report the absence of complications (with calculated upper limit 95% confidence interval of approximately 13.6%) when hypotensive epidural anesthesia was performed in 22 patients with noncritical asymptomatic aortic stenosis.

Symptomatic thromboembolism after one-stage bilateral THA with a multimodal prophylaxis protocol.

To determine the incidence of thromboembolism after one-stage bilateral total hip arthroplasty and the role of two different chemoprophylaxis agents, we retrospectively studied 644 consecutive patients who underwent one-stage bilateral total hip arthroplasties. All patients received a similar multimodal prophylaxis protocol, which differed only in the postoperative chemoprophylaxis: 292 patients received warfarin (Group 1) and 352 received aspirin (Group 2). All patients were followed for a minimum of 3 months. We observed no difference in the incidence of symptomatic venous thrombosis, pulmonary embolism, or mortality in the two groups. Twenty patients in each group had deep venous thrombosis (7% and 5.7%, respectively) develop. Seven patients (2.39%) in Group 1 and eight (2.27%) in Group 2 had proximal deep venous thrombosis. Four patients in each group had a nonfatal pulmonary embolism (1.36% and 1.13%, respectively). There were two deaths in each group, neither related to venous thromboembolism. One-stage bilateral total hip arthroplasties were associated with a low rate of venous thrombosis and embolism with our multimodal prophylaxis protocol, and we found no difference in the incidence of either in patients who received warfarin or aspirin for chemoprophylaxis.