Venous pressure during intravenous regional anesthesia: Implications for setting tourniquet pressure

Background and Aims: Intravenous regional anesthesia (IVRA) is utilized for upper extremity surgery, but higher tourniquet pressure and longer inflation time increase the risk of soft tissue and nerve injury. We investigated the duration and magnitude of elevated venous pressure during IVRA to assess the possibility of safely lowering the tourniquet pressure during surgery. Material and Methods: Twenty adult patients scheduled for distal upper extremity surgery were enrolled. An additional intravenous catheter was placed in the surgical arm connected to a digital pressure transducer for monitoring venous pressure. Venous pressure was recorded prior to IVRA and every 30 s after injection of local anesthetic (LA) until the completion of surgery. Results: All 20 subjects completed the study without complication. Peak venous pressure was 340 mmHg in one patient which lasted for less than 30 s. Mean venous pressures fell below systolic blood pressure after 4.5 min in all cases except one. This patient had elevated venous pressures for 24 of 25 min of tourniquet time exceeding systolic blood pressure. The only statistically significant intraoperative factor associated with elevated venous pressure was elevated peak systolic pressure (P = 0.001). Conclusions: We found that the mean peak venous pressure was below systolic blood pressure in only 14 of the 20 subjects, and the peak injection pressure exceeded 300 mmHg in one patient. Another patient's venous pressure remained above systolic blood pressure for 24 of 25 min of tourniquet time. Current precautions to prevent LA toxicity may be insufficient in some patients and attempts to lower tourniquet pressures to just above systolic blood pressures soon after IVRA injection may result in toxicity, specifically if systolic pressure is elevated

Radiographic diagnosis of scapholunate dissociation among intra-articular fractures of the distal radius: interobserver reliability

PURPOSE: To evaluate the reliability and accuracy of diagnosis of scapholunate dissociation (SLD) among AO type C (compression articular) fractures of the distal radius. METHODS: A total of 217 surgeons evaluated 21 sets of radiographs with type C fractures of the distal radius for which the status of the scapholunate interosseous ligament was established by preoperative 3-compartment computed tomographic arthrography with direct operative visualization of diagnosed SLD (reference standard). Observers were asked whether SLD was present, and if yes, whether they would recommend operative treatment. Diagnostic performance characteristics were calculated with respect to the reference standard. We assessed interobserver reliability using the Fleiss generalized kappa. RESULTS: The interobserver agreement for radiographic diagnosis of SLD was moderate (κ = 0.44). Correct diagnosis for a given set of radiographs ranged from 8% to 98% (average, 79%) of observers. Diagnostic performance characteristics were: 69% sensitivity, 84% specificity, 84% accuracy, 68% positive predictive value, and 84% negative predictive value. Based on a prevalence of 5%, Bayes adjusted positive and negative predictive values were 18% and 98%, respectively. Raters recommended operative treatment in 74% to 100% of patients diagnosed with SLD. CONCLUSIONS: Radiographs are moderately reliable and are better at ruling out than ruling in SLD associated with type C fracture of the distal radius

Factors associated with surgeon recommendation for additional cast immobilization of a CT-verified nondisplaced scaphoid waist fracture

Introduction: Data from clinical trials suggest that CT-confirmed nondisplaced scaphoid waist fractures heal with less than the conventional 8–12 weeks of immobilization. Barriers to adopting shorter immobilization times in clinical practice may include a strong influence of fracture tenderness and radiographic appearance on decision-making. This study aimed to investigate (1) the degree to which surgeons use fracture tenderness and radiographic appearance of union, among other factors, to decide whether or not to recommend additional cast immobilization after 8 or 12 weeks of immobilization; (2) identify surgeon factors associated with the decision to continue cast immobilization after 8 or 12 weeks. Materials and methods: In a survey-based study, 218 surgeons reviewed 16 patient scenarios of CT-confirmed nondisplaced waist fractures treated with cast immobilization for 8 or 12 weeks and recommended for or against additional cast immobilization. Clinical variables included patient sex, age, a description of radiographic fracture consolidation, fracture tenderness and duration of cast immobilization completed (8 versus 12 weeks). To assess the impact of clinical factors on recommendation to continue immobilization we calculated posterior probabilities and determined variable importance using a random forest algorithm. Multilevel logistic mixed regression analysis was used to identify surgeon characteristics associated with recommendation for additional cast immobilization. Results: Unclear fracture healing on radiographs, fracture tenderness and 8 (versus 12) weeks of completed cast immobilization were the most important factors influencing surgeons’ decision to recommend continued cast immobilization. Women surgeons (OR 2.96; 95% CI 1.28–6.81, p = 0.011), surgeons not specialized in orthopedic trauma, hand and wrist or shoulder and elbow surgery (categorized as ‘other’) (OR 2.64; 95% CI 1.31–5.33, p = 0.007) and surgeons practicing in the United States (OR 6.53, 95% CI 2.18–19.52, p = 0.01 versus Europe) were more likely to recommend continued immobilization. Conclusion: Adoption of shorter immobilization times for CT-confirmed nondisplaced scaphoid waist fractures may be hindered by surgeon attention to fracture tenderness and radiographic appearance

Scapula fractures: interobserver reliability of classification and treatment

OBJECTIVES:There is substantial variation in the classification and the management of scapula fractures. The first purpose of this study was to analyze the interobserver reliability of the OTA/AO and the New International Classification of scapula fractures. The second purpose was to assess the proportion of agreement among orthopaedic surgeons on operative or nonoperative treatment. DESIGN:: Web-based reliability study SETTING:: Independent orthopaedic surgeons from several countries were invited to classify scapular fractures in an online survey. PARTICIPANTS:One-hundred and three orthopaedic surgeons evaluated 35 movies of 3DCT-reconstruction of selected scapular fractures, representing a full spectrum of fracture patterns. MAIN OUTCOME MEASUREMENTS:Fleiss' kappa (κ) was used to assess the reliability of agreement between the surgeons. RESULTS:: The overall agreement on the OTA/AO Classification was moderate for the types (A, B, and C, κ = 0.54) with a 71% proportion of rater agreement (PA) as well as for the nine groups (A1 to C3, κ = 0.47) with a 57% PA. For the New International Classification, the agreement about the intra-articular extension of the fracture (Fossa (F), κ = 0.79) was substantial, the agreement about a fractured body (Body (B), κ = 0.57) or process was moderate (Process (P), κ = 0.53), however PAs were more than 81%. The agreement on the treatment recommendation was moderate (κ = 0.57) with a 73% PA. CONCLUSIONS:The New International Classification was more reliable. Body and process fractures generated more disagreement than intra-articular fractures and need further clear definitions