Hypoxemia following hospital discharge after fast-track hip and knee arthroplasty - A prospective observational study subanalysis.

BACKGROUND: Post-operative hypoxemia is prevalent in hospitalized patients and may adversely affect recovery. However, little data exist on the post-discharge phase or details on duration, severity and potential risk factors. Thus, we investigated the incidence and risk factors for severe desaturation during the first post-operative week after THA/TKA by continuous nocturnal oxygen saturation monitoring. METHODS: The study was a secondary analysis of a prospective cohort study of 112 patients undergoing fast-track THA/TKA. Patients with known sleep apnoea were excluded. Oxygen saturation and heart rate were recorded by a wireless wrist-worn pulse oximeter 2 nights before and 7 nights after surgery. Data on demographics, opioid consumption and cognitive function were collected from medical charts, patient diaries and clinical testing respectively. The primary outcome was occurrence of severe desaturation defined as periods with saturation <85% lasting ≥10 minutes. Secondary outcomes included description of various saturation levels and relevant risk factors. RESULTS: Severe oxygen desaturation occurred in 35% of the patients during the first post-operative week. Duration and severity of hypoxemic episodes increased after the first post-operative day. Pre-operative episodes of hypoxemia significantly increased the risk of post-operative hypoxemic events (OR 2.4-4.4, CI 0.4-46), while pre- and post-operative opioid use, age, gender, ASA classification, type of surgery or anaesthesia were significantly related to the development of post-operative hypoxemia. CONCLUSIONS: One third of the patients suffered from increased and prolonged episodes of severe nocturnal hypoxemia during the first week after THA/TKA discharge. Increased risk for severe hypoxemic episodes was related to pre-operative hypoxemia.

Early patient-reported outcomes versus objective function after total hip and knee arthroplasty: a prospective cohort study.

AIMS: The purpose of this study was to assess early physical function after total hip or knee arthroplasty (THA/TKA), and the correlation between patient-reported outcome measures, physical performance and actual physical activity (measured by actigraphy). PATIENTS AND METHODS: A total of 80 patients aged 55 to 80 years undergoing THA or TKA for osteoarthritis were included in this prospective cohort study. The main outcome measure was change in patient reported hip or knee injury and osteoarthritis outcome score (HOOS/KOOS) from pre-operatively until post-operative day 13 (THA) or 20 (TKA). Secondary measures were correlations to objectively assessed change in physical performance (paced-walk, chair-stand, stair-climb tests) at day 14 (THA) or 21 (TKA) and actual physical activity (actigraphy) measured at day 12 and 13 (THA) or 19 and 20 (TKA). RESULTS: Patients reported improved physical function (HOOS or KOOS) pre-operatively until day 13 (THA) or 20 (TKA) with a mean difference of 7 (95% confidence interval (CI) 1 to 13, p = 0.033) and 6 (95% CI 1 to 12, p = 0.033) percentage points, respectively. By contrast, objectively assessed physical function and activity declined, with no correlations between subjective and objective assessments for either THA or TKA patients (r2 ≤ 0.16, p ≥ 0.314). CONCLUSIONS: Early improvement in patient-reported physical function after THA/TKA does not correlate with objectively assessed function, and patient reported outcomes should not be used as the only measure of recovery. Cite this article: Bone Joint J 2017;99-B:1167-75.

Clinical, nociceptive and psychological profiling to predict acute pain after total knee arthroplasty.

BACKGROUND: Pre-operative identification of high-pain responders for acute pain after total knee arthroplasty (TKA) could lead to targeted analgesic trials and individualized analgesic strategies to improve recovery and potentially reduce the risk of persistent post-surgical pain. The aim of this study was to use simple clinical tests and questionnaires to identify predictive nociceptive and psychological factors for acute post-TKA pain. METHODS: Sixty consecutive TKA patients were included in a prospective descriptive study of pain during a 5-m walk-test 24 h post-operatively as the primary outcome. Predictive variables collected prior to surgery included demographics, nociceptive testing (pressure pain threshold (PPT), cold pressor tolerance, electrical pain threshold and tolerance) and psychological profile (pain catastrophizing scale (PCS) and hospital anxiety and depression scale). The prediction of acute post-TKA pain was assessed by univariate analysis, logistic regressions and ROC curves. RESULTS: Reduced PPT on the arm and increased PCS were predictive variables for moderate/severe post-TKA pain 24 h after surgery (P = 0.007 and P = 0.026, respectively, R-squared 0.21) in the logistic regression model. Odds ratios were 0.67 for a 50 kPa increased PPT and 1.36 for a 5 point increase in PCS. A predictive model with cut-off values of PPT ≤ 245 kPa and PCS≥ 8 point had a sensitivity of 71.4 and a specificity of 62.5. CONCLUSION: Pre-operative widespread pressure pain hypersensitivity and pain catastrophizing are predictive of moderate severe post-TKA pain. If validated in a larger population, the clinically applicable tests should be considered in future interventions aiming to minimize post-operative pain in high-risk patients.

Challenges in postdischarge function and recovery: the case of fast-track hip and knee arthroplasty.

This narrative review updates the recent advances in our understanding of the multifactorial pathogenesis for reduced postdischarge physical and cognitive function after fast-track surgery, using total hip and knee arthroplasty as surgical models. Relevant factors discussed include the surgical stress responses and potential methods for controlling postsurgical inflammation, pain, and cognitive dysfunction. The continuation of moderate to severe pain in up to 30% of patients for 2-4 weeks calls for better understanding of the underlying mechanisms and development of effective multimodal opioid-sparing analgesic regimens. The need for the development of effective physiotherapy programmes on a patient-specific basis is discussed, along with the need for optimal assessment of postoperative function to guide rehabilitation. Other relevant factors discussed include the role of orthostatic intolerance, sleep disturbances, and blood management, and specific patient populations at risk for adverse outcomes, including psychiatric disorders, to identify and guide future interventions for optimizing functional postdischarge outcomes after fast-track surgery.