A higher altitude is an independent risk factor for venous thromboembolisms following total shoulder arthroplasty

Pulmonary embolism after shoulder surgery: Is it a real threat?

Pulmonary embolism (PE) is a rare but devastating complication of shoulder surgery. Apart from increased morbidity and mortality rates, it may significantly impair postoperative recovery and functional outcome. Its frequency accounts for up to 5.7% of all shoulder surgery procedures with a higher occurrence in women and patients older than 70 years. It is most commonly associated with thrombophilia, diabetes mellitus, obesity, smoking, hypertension, and a history of malignancy. PE usually occurs secondary to upper or lower-extremity deep vein thrombosis (DVT). However, in rare cases, the source of the thrombi cannot be determined. Prophylaxis for PE following shoulder surgery remains a topic of debate, and the standard of care does not routinely require prophylactic medication for DVT prophylaxis. Early ambulation and elastic stockings are important preventative measures for DVT of the lower extremity and medical agents such as aspirin, low-molecular-weight heparin, and vitamin K antagonists are indicated for high-risk patients, long-lasting operations, or concomitant severe acute respiratory syndrome coronavirus 2 infection. The most common symptoms of PE include chest pain and shortness of breath, but PE can also be asymptomatic in patients with intrinsic tolerance of hypoxia. Patients with DVT may also present with swelling and pain of the respective extremity. The treatment of PE includes inpatient or outpatient anticoagulant therapy if the patient is hemodynamically unstable or stable, respectively. Hemodynamic instability may require transfer to the intensive care unit, and cardiovascular arrest can be implicated in fatal events. An important issue for patients with PE in the postoperative period after shoulder surgery is residual stiffness due to a delay in rehabilitation and a prolonged hospital stay. Early physiotherapy and range-of-motion exercises do not adversely affect the prognosis of PE and are highly recommended to preserve shoulder mobility and function.

Anesthesia strategies for elderly patients with craniocerebral injury due to foreign-body penetration in the plateau region: a case report

Background

The administration of anesthesia for elderly individuals who are critically ill, suffering from severe craniocerebral injuries, and living in plateau regions presents a rare, intricate, and high-risk challenge. This case study outlines the specific anesthesia management protocols necessary for plateau-dwelling patients with significant craniocerebral damage undergoing prolonged invasive procedures.

Case report

A 76-year-old male patient had a 26-year history of foreign-body penetration of the skull and had experienced local purulent discharge and pain for the previous 20 days. The diagnoses included right hypoplasia, a foreign body in the skull with an infection, hypokalemia, hypoproteinemia, pulmonary fibrous foci, and bilateral pleural effusion. For almost 6 months, the patient suffered from recurring headaches, blurred vision, and sluggish bodily movement. The patient had a poor diet, poor sleep quality, normal urination, and no noticeable weight loss since the onset of the illness. The right anterior ear had a 2 cm skin abscess with yellow pus and a black metal foreign body tip. The left eyelid was red and swollen, and the left conjunctiva was hyperemic; the right eyelid showed no abnormalities, and both pupils were wide and round, with light and adjustment reflexes and no cyanosis on the lips. Skull development was normal. No dry or moist rales were audible in either lung. The heart rhythm was regular, and the heart rate was 50 bpm. Chest CT revealed left lung calcification foci, bilateral pleural effusion, and fiber foci in the lower lobes of both lungs.

Conclusion

Furthermore, the patient in question was of advanced age and had a complex medical history, including prolonged exposure to high altitudes and previous instances of severe craniocerebral trauma, among other uncommon pathophysiological characteristics. In particular, the patient also underwent surgical interventions at both high and low altitudes, adding to the complexity of their case. To ensure patient safety, close multidisciplinary collaboration, the development of a precise surgical plan, and the implementation of a suitable perioperative anesthetic management strategy are imperative.

The cardiovascular system at high altitude: A bibliometric and visualization analysis

BACKGROUND

When exposed to high-altitude environments, the cardiovascular system undergoes various changes, the performance and mechanisms of which remain controversial.

AIM

To summarize the latest research advancements and hot research points in the cardiovascular system at high altitude by conducting a bibliometric and visualization analysis.

METHODS

The literature was systematically retrieved and filtered using the Web of Science Core Collection of Science Citation Index Expanded. A visualization analysis of the identified publications was conducted employing CiteSpace and VOSviewer.

RESULTS

A total of 1674 publications were included in the study, with an observed annual increase in the number of publications spanning from 1990 to 2022. The United States of America emerged as the predominant contributor, while Universidad Peruana Cayetano Heredia stood out as the institution with the highest publication output. Notably, Jean-Paul Richalet demonstrated the highest productivity among researchers focusing on the cardiovascular system at high altitude. Furthermore, Peter Bärtsch emerged as the author with the highest number of cited articles. Keyword analysis identified hypoxia, exercise, acclimatization, acute and chronic mountain sickness, pulmonary hypertension, metabolism, and echocardiography as the primary research hot research points and emerging directions in the study of the cardiovascular system at high altitude.

CONCLUSION

Over the past 32 years, research on the cardiovascular system in high-altitude regions has been steadily increasing. Future research in this field may focus on areas such as hypoxia adaptation, metabolism, and cardiopulmonary exercise. Strengthening interdisciplinary and multi-team collaborations will facilitate further exploration of the pathophysiological mechanisms underlying cardiovascular changes in high-altitude environments and provide a theoretical basis for standardized disease diagnosis and treatment.

Does living at high altitude increase the risk of bleeding events after total knee arthroplasty? A retrospective cohort study

OBJECTIVE

Post-operative bleeding after total knee arthroplasty (TKA) is a frequent cause of post-operative complications. This study compared blood loss and indicators of coagulation and fibrinolysis between TKA patients living at low or high altitudes.

METHODS

We retrospectively analyzed 120 patients at our institution who underwent primary TKA from May 2019 to March 2020, and we divided them into those living in areas about 500 m or > 3000 m above sea level. We compared the primary outcome of total blood loss between them. We also compared them in terms of several secondary outcomes: coagulation and fibrinolysis parameters, platelet count, reduction in hemoglobin, hidden blood loss, intra-operative blood loss, transfusion rate, and incidence of thromboembolic events and other complications.

RESULTS

Total blood loss was significantly higher in the high-altitude group than in the low-altitude group (mean, 748.2 mL [95% CI, 658.5-837.9] vs 556.6 mL [95% CI, 496.0-617.1]; p = 0.001). The high-altitude group also showed significantly longer activated partial thromboplastin time, prothrombin time, and thrombin time before surgery and on post-operative day one, as well as increased levels of fibrinogen/fibrin degradation product on post-operative days one and three. Ecchymosis was significantly more frequent in the high-altitude group (41.7 vs 21.7%; relative risk (RR) = 1.923 [95% CI, 1.091-3.389]; p = 0.019). The two groups showed similar transfusion rates, and none of the patients experienced venous thromboembolism, pulmonary embolism, or infection.

CONCLUSION

High altitude may alter coagulation and fibrinolysis parameters in a way that increases risk of blood loss after TKA. Such patients may benefit from special management to avoid bleeding events.

Commercial Claims Data Sources: PearlDiver and Individual Payer Databases

Individual or pooled commercial claims data sources such as the IBM MarketScan and PearlDiver provide information from health-care encounters by individuals enrolled in participating health insurance plans. These data sources contain deidentified data on demographic characteristics, enrollment start and end dates, inpatient and outpatient procedures and medical diagnoses with associated service dates and settings, and dispensed medications. Although there are concerns that long-term follow-up is limited because of interruptions in the continuity of coverage and reliance on billing data may overrecord or underrecord diagnoses and confounders, these data sources are nevertheless valuable for orthopaedic studies focusing on short-term complications, costs, and utilization.

Venous Thromboembolism After Total Shoulder Arthroplasty: A Database Study of 31,918 Cases

INTRODUCTION

Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT), is a rare but serious complication of total shoulder arthroplasty (TSA). Owing to limited evidence, Clinical Practice Guideline recommendations for VTE chemoprophylaxis after TSA rely heavily on the risk stratification of individual patients. The objectives of this study were to identify the prevalence and risk factors independently associated with VTE, PE, and DVT in the 30-day postoperative period after TSA.

METHODS

A retrospective case-control study was conducted using the American College of Surgeons National Surgical Quality Improvement Program database by querying the Current Procedural Terminology code for total shoulder arthroplasty from 2011 to 2020. The initial query resulted in 33,089 patients. After applying exclusion criteria for age younger than 50 years, emergency surgery, and open wound or infection, a final cohort of 31,918 patients who underwent TSA were included. The primary outcome was venous thromboembolism, and secondary outcome variables were PE and DVT. A bivariate screen was done for explanatory variables associated with our outcome variables, and variables with P < 0.1 in the bivariate screen were included in a multivariable logistic regression model.

RESULTS

Of the 31,918 patients in our cohort, 183 patients (0.573%) developed VTE, 92 patients (0.29%) developed PE, and 104 patients (0.326%) developed DVT during the 30-day postoperative period. Multivariable logistic regression analysis showed that older age, higher body mass index, longer surgical time, and longer hospital length of stay were associated with VTE and PE and that hypertension and shorter hospital length of stay were associated with DVT.

DISCUSSION

The prevalence of VTE after TSA is low. Older patients, patients with higher body mass index, and patients with longer surgical durations are at higher risk for VTE after TSA. Our findings are relevant for preoperative risk stratification and the decision for chemoprophylaxis.

LEVEL OF EVIDENCE

Level III Prognostic.

Impact of high altitude on the incidence of postoperative venous thromboembolism and its genetic susceptibility: A meta-analysis and systematic review

BACKGROUND

The effect of high-altitude (HA) on venous thromboembolism (VTE) and its mechanism remains ambiguous. To clarify this, we aimed to conduct a meta-analysis and systematic review to evaluate the incidence of VTE at HA and comparatively low altitude (LA) and figure out the intrinsic risk factors such as susceptibility genes of patients with VTE at HA.

METHODS

We selected studies that explored the risk factors for HA and VTE by searching PubMed, Embase, and Web of Science to analyze the impact of HA on VTE. All relevant studies before August 2021 were screened using the terms ([high altitude] OR [plateau] OR [mountain]) AND ([venous thromboembolism] OR [deep vein thrombosis] OR [pulmonary embolism]). Latest studies on the gene of HA-VTE patients were also summarized and analyzed.

RESULTS

Fifteen studies were eventually assessed, and the overall numbers of subjects with and without VTE were 1475 and 286,926 respectively. The overall incidence of VTE, deep vein thrombosis (DVT) and pulmonary embolism (PE) in the HA group was significantly higher than that in the LA group (P < 0.01). The overall incidence of VTE, DVT and PE in the HA group was significantly higher than that in the LA group at 30 days post operation (P < 0.05, P < 0.05 and P < 0.01, respectively). At 90 days post operation, incidence of VTE and PE in the HA group was higher than that in the LA group (P < 0.01and P < 0.01, respectively), but there was no difference in the incidence of DVT (P = 0.07). Regarding endogenous factors, the analysis of genes in patients with HA-VTE revealed numerous targeted genes such as ANG, ACE, lncRNA-LINC00 659/UXT-AS1 and GP4.

CONCLUSIONS

We observed a significant association between HA and the overall incidence of VTE and that at 30/90 days post operation, indicating that HA may be a risk factor for VTE.

High Altitude as a Risk Factor for Venous Thromboembolism in Tibial Plateau Fractures

Background: Tibial plateau fractures are often significant injuries that can require complex surgical interventions with prolonged perioperative immobilization, thereby increasing the risk of developing venous thromboembolic (VTE) events, specifically, deep vein thrombosis (DVT) and pulmonary embolism (PE). Risk stratification is paramount for guiding VTE prophylaxis. Although high altitude has been suggested to create a prothrombotic state, virtually no studies have explored its clinical effects in lower extremity trauma. The purpose of this study was to compare surgical fixation of tibial plateau fractures at high and low altitudes and its effects on post-operative VTE development.

Methods: The Truven MarketScan claims database was used to retrospectively identify patients who underwent surgical fixation of isolated and closed tibial plateau fractures using Current Procedural Terminology (CPT) codes over a 10-year period. Extraneous injuries were excluded using the International Classification of Diseases, 10^th edition (ICD-10), and CPT codes. Patient demographics, comorbidities, and DVT chemoprophylaxis prescriptions were obtained. Patients were partitioned into high altitude (>4000 feet) or low altitude (<100 feet) cohorts based on the zip codes of their surgery locations. One-to-one matching and univariate analysis were used to assess and control any baseline discrepancies between cohorts; multivariate regression was then performed between cohorts to determine the odds ratios (OR) for developing VTEs post-operatively.

Results: There were 7,832 patients included for analysis. There was no statistical difference between high and low altitude cohorts in developing VTEs within 30 days post-operatively. Higher altitudes were associated with increased odds of developing DVT (OR 1.21, p = 0.043) and PE (OR 1.27, p = 0.037) within 90 days post-operatively.

Conclusions: Surgical fixation of tibial plateau fractures is associated with an increased risk of developing VTEs at high altitudes within 90 days post-operatively. Understanding such risk factors in specific orthopaedic patient populations is essential for optimizing DVT prophylaxis protocols. Further studies should investigate this relationship and the role of DVT prophylaxis regimens in this population. 

A Higher Altitude Is Associated with Increased Incidence of Infections following Primary Total Hip Arthroplasty

Purpose

The purpose of this study was to evaluate whether patients undergoing primary total hip arthroplasty (THA) at a higher elevation have higher rates of: 1) in-hospital length of stay (LOS); 2) surgical site infections (SSIs); 3) periprosthetic joint infections (PJIs); and 4) costs.

Materials and Methods

The Medicare claims database was used to identify patients who underwent primary THA at an altitude higher than 4,000 feet (ft). High-altitude patients were matched to patients who underwent primary THA at an altitude less than 100 ft, yielding 24,958 and 124,765 patients respectively. Outcomes that were assessed included in-hospital LOS, SSIs, PJIs, and costs of care. A P-value less than 0.001 was considered statistically significant.

Results

Patients in the study group had significantly longer in-hospital LOS (4 days vs 3 days, P<0.0001). In addition, patients in the study group had a significantly higher incidence and odds of developing SSIs (1.16% vs 0.86%; odds ratio [OR], 1.34; P<0.0001) and PJIs (0.91% vs 0.58%; OR, 1.56; P<0.0001) within 90-days following the index procedure, compared to matched controls. Higher altitude patients incurred higher day of surgery ($16,139.76 vs $15,279.42; P<0.0001) and 90-day costs ($18,647.51 vs $16,401.62; P<0.0001).

Conclusion

This study demonstrated that primary THA procedures performed at an elevation higher than 4,000 ft are associated with longer in-hospital LOS, higher rates of SSIs, PJIs, and costs of care. Orthopedists and other healthcare professionals can use this information to provide adequate education for these patients regarding the potential complications that may occur following their procedure.

Venous thromboembolism complications in shoulder surgery: current concepts

Venous thromboembolism (VTE) is a rare yet known complication of shoulder surgery. Concerning shoulder arthroplasty, reported rates of VTE range from 0.2% to 16%. Unlike many lower extremity procedures, particularly total hip and knee arthroplasty, chemical prophylactic guidelines for VTE in shoulder surgeries have not been established. Some argue that doing so is unnecessary. On the contrary, mechanical prophylaxis is nearly universally accepted in shoulder surgery, particularly for more lengthy procedures. With limited VTE incidence in shoulder surgery, treatment is anecdotally derived from the hip and knee arthroplasty literature. Recent studies have successfully identified risk factors for VTE related to the patient and to the surgery itself. Awareness of these risk factors by the surgeon and declaration of these factors to the patient should be discussed as part of the informed consent process. Further investigational studies and larger patient cohorts will be necessary to optimise VTE prevention in shoulder surgeries.

Higher altitude leads to increased risk of venous thromboembolism after acetabular and pelvic ring injury

INTRODUCTION

There is a high post-operative incidence of venous thromboembolisms (VTEs), specifically deep vein thrombosis (DVT) and pulmonary embolism (PE), in pelvic ring and acetabular fractures, and identification of risk factors for VTEs is crucial to decrease this highly morbid complication. High altitudes have a known physiological effect on the body that may predispose patients to developing VTEs in the postoperative period. The purpose of this study was to investigate the relationship between pelvic ring and acetabular fractures occurring at high altitudes and the development of postoperative VTEs.

METHODS

In this retrospective study, the Truven MarketScan claims database was used to identify patients who underwent surgical fixation of a pelvic ring and/or acetabular fracture from January 2009 to December 2018 using Current Procedural Terminology (CPT) codes. Patient characteristics, including medical comorbidities, were collected. The zip codes of where the surgeries took place were used to determine recovery altitude and patients were separated into either the high altitude (>4000 feet) or low altitude (<100 feet) cohorts. Chi-squared and multivariate analyses were performed to investigate the association between altitude and the development of VTE postoperatively.

RESULTS

In total, 68,923 patients were included for analysis. At 30-days postoperatively, a higher altitude was associated with increased odds of developing a PE (OR 1.47, p = 0.019). At 90-days postoperatively, a higher altitude was associated with increased odds of DVT (OR 1.24, p = 0.029) and PE (OR 1.63, p < 0.001).

CONCLUSION

Surgical fixation of pelvic ring and acetabular fractures performed at a higher altitude (>4,000feet) are associated with increased odds of developing a PE in the first 30 days as well as developing a DVT or PE at 90 days postoperatively. Future prospective studies are needed to further elucidate the causality of altitude on the development of postoperative VTEs.

High Altitude Is an Independent Risk Factor for Developing a Pulmonary Embolism, but Not a Deep Vein Thrombosis Following a 1- to 2-Level Lumbar Fusion

STUDY DESIGN

Retrospective study.

OBJECTIVE

To identify if a 1- to 2-level posterior lumbar fusion at higher altitude is an independent risk factor for postoperative deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

A national Medicare database was queried for all patients undergoing 1- to 2-level lumbar fusions from 2005 to 2014. Those with a prior history of DVT, PE, coagulopathy, or peripheral vascular complications were excluded to better isolate altitude as the dependent variable. The groups were matched 1:1 based on age, gender, and comorbidities to limit potential cofounders. Using ZIP codes of the hospitals where the procedure occurred, we separated our patients into high (>4000 feet) and low (<100 feet) altitudes to investigate postoperative rates of DVTs and PEs at 90 days.

RESULTS

Compared with lumbar fusions performed at low-altitude centers, patients undergoing the same procedure at high altitude had significantly higher PE rates (P = .010) at 90 days postoperatively, and similar rates of 90-day postoperative DVTs (P = .078). There were no significant differences in age or comorbidities between these cohorts due to our strict matching process (P = 1.00).

CONCLUSION

Spinal fusions performed at altitudes >4000 feet incurred higher PE rates in the first 90 days compared with patients receiving the same surgery at <100 feet but did not incur higher rates of postoperative DVTs.

Risk factors for venous thromboembolism in total shoulder arthroplasty

BACKGROUND

Although venous thromboembolism (VTE) has been studied in lower-extremity arthroplasty, there are few guidelines regarding established risk factors for VTE in total shoulder arthroplasty (TSA). With literature suggesting the VTE rate may be as high as 13%, VTE prevention and risk factors should be considered in preoperative planning.

METHODS

All TSAs from 2011 through 2016 were queried from the National Surgical Quality Improvement Program database. Age, sex, body mass index, American Society of Anesthesiologists class, ethnicity, functional status, comorbidities, discharge destination, surgical indication, length of stay, and operative time were compared between patients with and without 30-day postoperative VTE. Pearson χ2 and t tests were used to assess baseline categorical and continuous variables, respectively. Multivariate logistic regression analysis was conducted to determine associated independent risk factors for VTE.

RESULTS

The analysis included 13,299 patients; VTE developed in 83 patients (0.62%). Patients with VTE were older (72 years vs. 69 years) and had a longer hospital stay (3.5 days vs. 1.9 days). Compared with patients with no VTE, patients with VTE were more likely to undergo TSA for proximal humeral fractures, to be discharged to a rehabilitative center, to have a preoperative albumin level lower than 3.5 g/dL, to undergo non-elective surgery, to have an American Society of Anesthesiologists class of 3 or greater, to have a surgical-site infection develop, and ultimately to need a shoulder reoperation (all P < .05). Multivariate logistic regression analysis revealed that hypoalbuminemia (albumin level < 3.5 g/dL), an increased length of stay, and African American ethnicity were independent risk factors for VTE development.

CONCLUSION

Patients with hypoalbuminemia, an increased length of stay, and African American ethnicity are at an increased risk of VTE after shoulder arthroplasty. A high index of suspicion is warranted for elderly patients with fractures who may need preoperative medical optimization.

Venous Thromboembolism at High Altitude: Our Approach to Patients at Risk

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a prevalent disorder that confers substantial cardiovascular morbidity and, in serious cases, death. VTE has a complex and incompletely understood etiopathogenesis with genetic, acquired, and environmental risk factors. As the focus of this review, one environmental risk factor, which may interact with other risk factors such as hereditary and/or acquired thrombophilias, is travel to high altitude (HA), although current evidence is limited. As guidelines do not directly address this topic, we will discuss the epidemiology of HA-VTE, review the putative mechanisms for thrombosis at HA, and discuss our clinical approach to both risk stratification and counseling, including specific pharmacologic and nonpharmacologic recommendations for patients with elevated VTE risk before they travel to HA.