Triage nurse application of the Ottawa knee rule

Are Oblique Views Necessary? A Review of the Clinical Value of Oblique Knee Radiographs in the Acute Setting

Introduction: The purpose of this study was to assess the added clinical value of oblique knee radiographs four-view (4V) compared to orthogonal anteroposterior (AP) and lateral radiographs in a two-view (2V) series. Methods: We obtained 200 adult, 4V knee radiographs in 200 patients in the ED and randomly divided them into two groups with 100 series in each group. Ten reviewers — three musculoskeletal radiologists and seven orthopedic surgeons — performed radiograph analyses. These reviewers were randomly divided evenly into group one and group two. Reviewers were blinded to patient data and first reviewed 2V radiographs (AP/lateral) only, and then reviewed 4V radiographs, including AP/lateral, and two additional oblique views for the same patients at least four weeks later. Acute pathology identification and the need for further imaging was assessed for all reviewers, and clinical decision-making (operative vs nonoperative treatment, need for admission, need for additional imaging) was assessed only by the seven orthopaedic surgeon reviewers. Results: Mean sensitivity for pathology identification was 79% with 2V and 81% with 4V (P =0.25). Intra-observer kappa value was 0.81 (range 0.54-1.00). Additional oblique radiographs led orthopaedic reviewers to change their treatment recommendations in 62/329 patients (18.84%) (P <0.001). Eight of 329 radiographic series were identified as “critical misses.” (2.43%) (P =0.004), when pathology was reported as normal or reviewers recommended nonoperative treatment on 2V radiographs but changed their recommendation to operative management after the addition of oblique radiographs. The number needed to treat (NNT) for any treatment change and for “critical misses” was 83 and 643, respectively. Conclusion: Although the addition of oblique radiographs may improve a clinician’s ability to identify subtle pathologic findings not identified on 2V, it rarely leads to significant changes in treatment recommendations. Given the high NNT, limiting the usage of these oblique radiographs in the general patient population may reduce costs without significantly affecting patient care.

Validation of the Ottawa knee rule in adults: A single centre study

INTRODUCTION

This clinical audit aimed to evaluate performance of the Ottawa Knee Rule (OKR) and degree of compliance by emergency referrers for acute knee injuries in adults.

METHODS

Knee radiography requests were analysed retrospectively for eligibility. Data were extracted from eligible requests under headings describing the OKR criteria, patient history, diagnosis and referrer profession. Sensitivity, specificity, negative likelihood ratio and positive likelihood ratio were calculated with 95% CI for the entire sample and each profession (consultant doctors, resident medical officers [RMO], physiotherapists and triage nurses) individually. The frequency of each OKR criterion and correlation with fracture, referrer compliance to the rule and the relative reduction in radiography were also calculated.

RESULTS

Of 713 patients identified, 149 were enrolled by the eligibility criteria. The overall sensitivity, specificity, negative likelihood ratio and positive likelihood ratio of the OKR for knee fracture were 71% (95%CI, 49-87%), 46% (95%CI, 37-55%), 0.64 (95%CI, 0.33-1.22) and 1.3 (95%CI, 0.96-1.76), respectively. Physiotherapists and triage nurses demonstrated better rule performance than consultant doctors and RMOs, with a sensitivity of 100% and negative likelihood ratio of 0.0. Physiotherapists were most compliant at 73% (19/26). Only 85 requests were OKR positive and, when abiding by the rule, this would have reduced radiography by 43% (64/149).

CONCLUSIONS

In this first Australian study, moderate OKR performance and variable compliance by emergency referrers were observed. This led to unnecessary irradiation of patients without a fracture. The findings suggest emergency referrers could benefit from education on applying and documenting the OKR on radiography requests.

Diagnostic accuracy of the Ottawa Knee Rule in adult acute knee injuries: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aimed to evaluate the current evidence on the diagnostic accuracy of the Ottawa Knee Rule (OKR) for acute knee injuries in adults.

METHODS

A literature search of Embase (Elsevier), MEDLINE (U.S. National Library of Medicine), PubMed and Scopus databases (1995 to date; English language) was performed and the relevant references were assessed. Original articles documenting OKR use by emergency physicians to assess adult acute knee injuries were included. Study methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Results of eligible studies were pooled using random effects or fixed effects modelling to calculate the diagnostic performance of the OKR. The Higgins I² test and Begg's association test were performed to assess between-study heterogeneity and publication bias respectively, with Spearman's correlation test for threshold effect.

RESULTS

Eight studies, including 7385 patients, were enrolled and pooled using the random effects model. Sensitivity, specificity, negative likelihood ratio, positive likelihood ratio and diagnostic odds ratio were 0.99 (95% CI, 0.97 to 1.00), 0.49 (95% CI, 0.47 to 0.51), 0.07 (95% CI, 0.02 to 0.24), 1.86 (95% CI, 1.72 to 2.01) and 25.10 (95% CI, 7.18 to 87.70) respectively. Based on the QUADAS-2 criteria, most studies presented low risk of bias and concern regarding applicability.

CONCLUSIONS

Application of the OKR can rule out knee fracture and thus avoid unnecessary radiography. These results also translate to improved efficiency, lower medical costs and reduced waiting times.

KEY POINTS

• The Ottawa Knee Rule helps clinicians to rule out fracture in adults with an acute knee injury. • The rule allows a reduction in radiography requests, patient waiting time in the emergency department and healthcare costs.

Nanomaterials Designed for Antiviral Drug Delivery Transport across Biological Barriers

Viral infections are a major global health problem, representing a significant cause of mortality with an unfavorable continuously amplified socio-economic impact. The increased drug resistance and constant viral replication have been the trigger for important studies regarding the use of nanotechnology in antiviral therapies. Nanomaterials offer unique physico-chemical properties that have linked benefits for drug delivery as ideal tools for viral treatment. Currently, different types of nanomaterials namely nanoparticles, liposomes, nanospheres, nanogels, nanosuspensions and nanoemulsions were studied either in vitro or in vivo for drug delivery of antiviral agents with prospects to be translated in clinical practice. This review highlights the drug delivery nanosystems incorporating the major antiviral classes and their transport across specific barriers at cellular and intracellular level. Important reflections on nanomedicines currently approved or undergoing investigations for the treatment of viral infections are also discussed. Finally, the authors present an overview on the requirements for the design of antiviral nanotherapeutics.

Perceived facilitators and barriers to clinical clearance of the cervical spine by emergency department nurses: A major step towards changing practice in the emergency department

OBJECTIVES

We conducted a validation study on use of the Canadian C-Spine Rule (CCR) by emergency department (ED) nurses to clear the c-spine in alert and stable trauma patients (N=3633). This survey sought to identify potential facilitators and barriers to an implementation policy that would allow nurses to clinically clear the c-spine of minor trauma patients.

METHODS

We conducted a prospective quantitative survey of ED nurses in six hospitals. Questions were developed from a previous qualitative survey at the same validation study EDs.

RESULTS

158 ED nurses were surveyed and 137 (86.7%) responded. Nurses strongly endorsed potential facilitators for nursing clearance of the c-spine, including 'Like to try new things at work' (96.4%) and 'Easy for me to take on new responsibilities' (96.4%). Most respondents were comfortable applying the rule (89.1%). Nurses endorsed potential barriers but at much lower rates, with the most common being 'Heavy workload makes it difficult to use the rule' (37.2%). Variation existed among hospitals for the facilitator 'Use of the rule would be useful to my practice', ranging from 81.8% to 100% endorsement (P=0.004).

CONCLUSIONS

This survey was an important step towards the goal of empowering ED nurses to clinically clear the c-spine of alert and stable trauma patients. There was a high rate of endorsement of facilitators and a low rate of endorsement of barriers. We found variation between hospitals, emphasizing the importance of understanding local beliefs when seeking to change clinical practice. We are conducting an implementation trial based on this feedback.

Evaluation of the safety of C-spine clearance by paramedics: design and methodology

BACKGROUND

Canadian Emergency Medical Services annually transport 1.3 million patients with potential neck injuries to local emergency departments. Less than 1% of those patients have a c-spine fracture and even less (0.5%) have a spinal cord injury. Most injuries occur before the arrival of paramedics, not during transport to the hospital, yet most patients are transported in ambulances immobilized. They stay fully immobilized until a bed is available, or until physician assessment and/or X-rays are complete. The prolonged immobilization is often unnecessary and adds to the burden of already overtaxed emergency medical services systems and crowded emergency departments.

METHODS/DESIGN

The goal of this study is to evaluate the safety and potential impact of an active strategy that allows paramedics to assess very low-risk trauma patients using a validated clinical decision rule, the Canadian C-Spine Rule, in order to determine the need for immobilization during transport to the emergency department.This cohort study will be conducted in Ottawa, Canada with one emergency medical service. Paramedics with this service participated in an earlier validation study of the Canadian C-Spine Rule. Three thousand consecutive, alert, stable adult trauma patients with a potential c-spine injury will be enrolled in the study and evaluated using the Canadian C-Spine Rule to determine the need for immobilization. The outcomes that will be assessed include measures of safety (numbers of missed fractures and serious adverse outcomes), measures of clinical impact (proportion of patients transported without immobilization, key time intervals) and performance of the Rule.

DISCUSSION

Approximately 40% of all very low-risk trauma patients could be transported safely, without c-spine immobilization, if paramedics were empowered to make clinical decisions using the Canadian C-Spine Rule. This safety study is an essential step before allowing all paramedics across Canada to selectively immobilize trauma victims before transport. Once safety and potential impact are established, we intend to implement a multi-centre study to study actual impact.

Multicentre prospective validation of use of the Canadian C-Spine Rule by triage nurses in the emergency department

OBJECTIVES

The Canadian C-Spine Rule for imaging of the cervical spine was developed for use by physicians. We believe that nurses in the emergency department could use this rule to clinically clear the cervical spine. We prospectively evaluated the accuracy, reliability and acceptability of the Canadian C-Spine Rule when used by nurses.

METHODS

We conducted this three-year prospective cohort study in six Canadian emergency departments. The study involved adult trauma patients who were alert and whose condition was stable. We provided two hours of training to 191 triage nurses. The nurses then assessed patients using the Canadian C-Spine Rule, including determination of neck tenderness and range of motion, reapplied immobilization and completed a data form.

RESULTS

Of the 3633 study patients, 42 (1.2%) had clinically important injuries of the cervical spine. The kappa value for interobserver assessments of 498 patients with the Canadian C-Spine Rule was 0.78. We calculated sensitivity of 100.0% (95% confidence interval [CI] 91.0%-100.0%) and specificity of 43.4% (95% CI 42.0%-45.0%) for the Canadian C-Spine Rule as interpreted by the investigators. The nurses classified patients with a sensitivity of 90.2% (95% CI 76.0%-95.0%) and a specificity of 43.9% (95% CI 42.0%-46.0%). Early in the study, nurses failed to identify four cases of injury, despite the presence of clear high-risk factors. None of these patients suffered sequelae, and after retraining there were no further missed cases. We estimated that for 40.7% of patients, the cervical spine could be cleared clinically by nurses. Nurses reported discomfort in applying the Canadian C-Spine Rule in only 4.8% of cases.

CONCLUSION

Use of the Canadian C-Spine Rule by nurses was accurate, reliable and clinically acceptable. Widespread implementation by nurses throughout Canada and elsewhere would diminish patient discomfort and improve patient flow in overcrowded emergency departments.

Can emergency department triage nurses appropriately utilize the Ottawa Knee Rules to order radiographs?-An implementation trial

OBJECTIVE

To determine whether triage nurses can successfully interpret the Ottawa Knee Rule (OKR) and order knee radiographs according to the OKR.

METHODS

This was a prospective implementation trial of a clinical decision rule, set in a suburban, community emergency department (ED), evaluating a convenience sample of ED patients aged > 17 years with acute knee injuries. Patients were excluded for altered mental status, distracting injuries, and knee lacerations. Triage nurses and attending emergency physicians (EPs) were trained in appropriate use of the OKR. The triage nurses evaluated eligible patients and radiographs were ordered according to their interpretation of the OKR. EPs who were initially blinded to the triage assessments also evaluated the patients. EPs could add an x-ray order if, according to their assessment of the OKR, one was indicated and a radiograph had not been ordered by the nurse. Nurses and EPs recorded their blinded assessments on standardized data collection instruments. Kappa values were calculated to assess interobserver agreement (IOA) between nurses and EPs; sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated as appropriate.

RESULTS

One hundred three patients were enrolled; 53% were female; 10 fractures were identified (9.7%). The IOAs between the nurses and EPs for each of the criteria were moderate to almost perfect: age-0.94; fibular head tenderness-0.4; isolated patellar tenderness-0.68; inability to bend knee to 90 degrees-0.73; inability to bear weight-0.76. The IOA was moderate (0.52) for the overall interpretation of the OKR by nurses and EPs. Sensitivity of nurse interpretation of the OKR for fracture was 70%, specificity 33%, NPV 91%, PPV 10%. Sensitivity of EP interpretation of the OKR for fracture was 100%, specificity 25%, NPV 100%, PPV 13%.

CONCLUSIONS

Triage nurses showed fair to good ability to appropriately apply the OKR to pre-order knee radiographs.

Ottawa Knee Rule: a comparison of physician and triage-nurse utilization of a decision rule for knee injury radiography

The Ottawa Knee Rule (OKR) is a clinical decision rule for the ordering of knee radiographs by physicians in patients with blunt knee injuries. However, in many Emergency Departments, radiographs are also ordered by nurses during triage. This study was designed to compare application of the OKR by triage nurses and physicians. A consecutive sample of all patients presenting to the Emergency Department (ED) of a tertiary care military teaching hospital with blunt knee injuries that met OKR inclusion criteria were enrolled. Radiographs were ordered on all patients. Nurses and physicians were blinded to each other's examinations. Nurse-physician inter-reviewer reliability was compared using the kappa statistic. Of 172 enrolled subjects, 38 were excluded for incomplete data or multiple entries, leaving 134 study patients. Four fractures (3%) were detected. Fair inter-observer reliability was found on four of the five OKR components: patellar tenderness (PT, kappa = 0.31), proximal fibula tenderness (PFT, kappa = 0.31), inability to flex > 90 degrees (FLEX, kappa = 0.24) and inability to walk four steps (WALK, kappa = 0.44). Nurses were more likely to overestimate the presence of individual components (PT 3.5x, PFT 6.6x, FLEX 1.9x and WALK 4.8x) and were 3.6 times more likely than Emergency Physicians (EP), overall, to order radiographs, representing a 21% vs. 37% reduced radiography rate, respectively. No fractures were missed by physicians or nurses. Triage nurses and EPs in this study had fair agreement in their application of the OKR. Triage nurses greatly overestimated knee injuries, while maintaining sensitivity, at the expense of specificity and cost savings.