David Petrie

Complications following management of displaced intra-articular calcaneal fractures: a prospective randomized trial comparing open reduction internal fixation with nonoperative management.

Objective To report on all complications experienced by patients with displaced intra-articular calcaneal fractures (DIACFs) following nonoperative management or open reduction internal fixation (ORIF). Design Prospective, randomized, multicenter study. Setting Four level I trauma centers. Patients The patient population consisted of consecutive patients, age 17 to 65 at the time of injury, presenting to 1 of the centers with DIACFs between April 1991 and December 1998. Interventions Patients were randomized to the nonoperative treatment group or to operative reduction using a lateral approach to the calcaneus. Main Outcome Measurements Follow-up for patients was at 2 weeks, 6 weeks, 3 months, 12 months, 24 months, and once greater than 24 months following injury. At each follow-up interval, patients were assessed for the development of major and minor complications. After a minimum of 2-year follow-up, patients were asked to fill out a validated visual analogue scale questionnaire (VAS) and a general health review (SF-36). Results There were 226 DIACFs (206 patients) in the ORIF group with 57 of 226 (25%) fractures (57 of 206 patients [28%]) having at least 1 major complication. Of 233 fractures (218 patients) nonoperatively managed, 42 (18%) (42 of 218 patients [19%]) developed at least 1 major complication (indirectly resulting in surgery). Conclusion Complications occur regardless of the management strategy chosen for DIACFs and despite management by experienced surgeons. Complications are a cause of significant morbidity for patients. Outcome scores in this study tend to support ORIF for calcaneal fractures. However, ORIF patients are more likely to develop complications. Certain patient populations (WCB and Sanders type IV) developed a high incidence of complications regardless of the management strategy chosen.

Displaced intra-articular calcaneal fractures: variables predicting late subtalar fusion.

Objective The goal of the current study was to analyze the prospective clinical outcome of patients who failed closed or open treatment of a displaced intra-articular calcaneal fracture. This cohort of patients required a secondary subtalar fusion by distraction bone-block arthrodesis. Design Review of prospective, randomized trial database. Setting Four level I trauma centers. Patients Between April 1, 1991 and December 31, 1997, 424 patients with 471 displaced intra-articular calcaneal fractures were involved in a large, multicenter, randomized trial. Forty-four patients who required subtalar fusion following initial treatment of a displaced intra-articular calcaneal fracture were compared to the population of patients who did not require subtalar fusion. The variables compared between the two groups included Böhler angles, two computed tomography classification systems, and clinical scores including SF-36, visual analogue score, and oral analogue score. Intervention Subtalar distraction bone-block arthrodesis with tricortical bone graft was used in all 45 feet. Main Outcome Measurements The following were examined: x-ray fracture classification, specifically Böhler angles and Essex-Lopresti classification; computed tomography classification, specifically Sanders and Crosby; clinical scores, specifically validated visual analogue score, general health survey scores, oral analogue score, and other factors (i.e., patient demographics including age, sex, profession, smoking history, and Workers Compensation Board involvement. Results Initial treatment of the 44 patients in our study was nonoperative in 37 (84%) patients and operative (open reduction and internal fixation) in 7 (16%) (1 patient had bilateral heel fractures). Patients requiring fusion differed demographically from those patients not requiring fusion. Mean age was 39 years in both the fusion and nonfusion group. The fusion group had 97% males, whereas the nonfusion group had 89% males. Sixty-four percent of the fusion patients were Workers Compensation Board claims, whereas 35% of the nonfusion group were Workers Compensation Board claims. Of those that required fusion, 77% were heavy laborers. On average, the fusion group had a Böhler angle 15° less than the nonfusion group. Forty-six percent of the fusion patients were Sanders-type IV initial fractures. Logistic regression analysis revealed that the primary predictors of requiring fusion were Workers Compensation Board status (odds ratio = 3.03, 95% confidence interval = 1.41–6.57), Sanders-type IV (odds ratio = 5.48, 95% confidence interval = 1.57–19.18), Böhler angle <0° (odds ratio = 10.64–95% confidence interval = 1.33–85.17), and nonoperative initial treatment (odds ratio = 5.86–95% confidence interval = 2.33–14.67). Conclusion These data suggest that the amount of initial injury involved with the calcaneal fracture is the primary prognostic determinant of long-term patient outcome. Böhler angle on presentation of <0° was 10 times more likely to require a secondary subtalar fusion than a Böhler angle on presentation of >15°. Sanders-type IV calcaneal fractures were 5.5 times more likely to be fused than a simple Sanders type II fracture. Workers Compensation Board patients were three times more likely to be fused than non-Workers Compensation Board patients. Nonoperative care was six times more likely to lead to a late fusion as compared to open reduction and internal fixation treatment. Late fusion provided relief from pain and improved function as evidenced by an improvement in visual analogue score postsurgery. This study demonstrates that there is a distinct patient group with a displaced intra-articular calcaneal fracture who are at high risk of subtalar fusion. These include male Workers Compensation Board patients who participate in heavy labor work with a fracture pattern with Böhler angle less than 0°. If their initial treatment was nonoperative, the likelihood of requiring late subtalar fusion was significantly increased. Initial open reduction and internal fixation of patients with displaced intra-articular calcaneal fracture minimized the likelihood that subtalar fusion would be required.

Inter-observer agreement using the Canadian Emergency Department Triage and Acuity Scale

OBJECTIVE To determine the inter-observer agreement on triage assignment by first-time users with diverse training and background using the Canadian Emergency Department Triage and Acuity Scale (CTAS). METHODS Twenty emergency care providers (5 physicians, 5 nurses, 5 Basic Life Support paramedics and 5 Advanced Life Support paramedics) at a large urban teaching hospital participated in the study. Observers used the 5-level CTAS to independently assign triage levels for 42 case scenarios abstracted from actual emergency department patient presentations. Case scenarios consisted of vital signs, mode of arrival, presenting complaint and verbatim triage nursing notes. Participants were not given any specific training on the scale, although a detailed one-page summary was included with each questionnaire. Kappa values with quadratic weights were used to measure agreement for the study group as a whole and for each profession. RESULTS For the 41 case scenarios analyzed, the overall agreement was significant (quadratic-weighted K = 0.77, 95% confidence interval, 0.76-0.78). For all observers, modal agreement within one triage level was 94.9%. Exact modal agreement was 63.4%. Agreement varied by triage level and was highest for Level I (most urgent). A reasonably high level of intra- and inter-professional agreement was also seen. CONCLUSIONS Despite minimal experience with the CTAS, inter-observer agreement among emergency care providers with different backgrounds was significant.

An evaluation of patient outcomes comparing trauma team activated versus trauma team not activated using TRISS analysis. Trauma and Injury Severity Score

OBJECTIVE The purpose of this study was to compare the outcomes of trauma patients with an Injury Severity Score (ISS) > 12 who had the trauma team involved (TTA) in their resuscitative care to those that did not (TTNA). SETTING Level I regional trauma center teaching hospital with university affiliation. METHODS All trauma patients admitted between July 1, 1991 and August 31, 1994 with an ISS > 12 were identified through the trauma registry. Burn patients, those who suffered their injury > 24 hours before admission, and deaths in the emergency room were excluded from analysis. The TRISS methodology, which offers a standard approval for evaluating outcomes for different populations of trauma patients, was used to determine whether there was a difference in outcomes between the two groups. To include patients who arrived at the trauma center intubated, a Trauma and Injury Severity Score (TRISS)-like analysis was also conducted on this patient population. MAIN RESULTS A total of 640 patients were identified; 174 (65.2%) in the TTA group and 223 (34.8%) in the TTNA group. A total of 448 (70%) were eligible for TRISS analysis and 574 (89.7%) were eligible for TRISS-like analysis. Using the TRISS analysis, the TTA group had a Z statistic of 3.36 yielding a W score of 4.27. This compared to the TTNA group whose Z statistic was 0.30. Using the TRISS-like logistic regression equation, the TTA group had a Z statistic of 6.50, yielding a W score of 8.60 compared with the TTNA group whose Z statistic was 0.88. After controlling for differences in the demographics of the two groups, the TTA still had consistently higher Z scores. CONCLUSION In a Level I trauma center, the outcomes of trauma patients with an ISS > 12 are statistically significantly better if the trauma team is activated than if the patients are managed on an individual service-by-service basis.

Effect of proximal and distal venting during intramedullary nailing.

During intramedullary manipulation, 2 main phenomena occur. A dramatic rise in intramedullary pressure occurs followed by intravasation of damaged marrow tissue. There are concerns about the development of increased interosseous pressure during reaming and the potential for this to contribute to fat embolism syndrome. The intramedullary pressures generated with various intramedullary devices was determined and the effects of a fracture, with and without proximal and distal venting on these pressures were studied. Pressures generated in 78 embalmed anatomic specimen femurs and tibias were studied, leaving all soft tissues intact. Pressures were recorded for awl, guide rod, reamer, and nail insertion. Venting was done by creating a 4.5-mm hole in the cortex directly opposite the transducer. Proximal venting reduced proximal pressures to 80 mm Hg in the tibia (90% reduction) and 460 mm Hg in the femur (70% reduction). Distal venting reduced distal pressures to 65 mm and 30 mm in the tibias and femurs, respectively (90% reduction in pressures). Intramedullary pressures generated during nail or alignment rod insertion in anatomic specimen bone greatly exceeds the critical thresholds (150 mm Hg) thought to be responsible for fat emboli to the lung in the dogs. The introduction of a vent may reduce the chance of fat embolism. Despite the high association of raised intramedullary pressures and fat emboli in animal studies, there is no known critical threshold for humans. Therefore, although venting seems effective in reducing the intramedullary pressure in anatomic specimen bones, its efficacy in the patient with trauma remains to be determined.

Out-of-Hospital Continuous Positive Airway Pressure Ventilation Versus Usual Care in Acute Respiratory Failure : A Randomized Controlled Trial

STUDY OBJECTIVE Continuous positive airway pressure ventilation (CPAP) in appropriately selected patients with acute respiratory failure has been shown to reduce the need for tracheal intubation in hospital. Despite several case series, the effectiveness of out-of-hospital CPAP has not been rigorously studied. We performed a prospective, randomized, nonblinded, controlled trial to determine whether patients in severe respiratory distress treated with CPAP in the out-of-hospital setting have lower overall tracheal intubation rates than those treated with usual care. METHODS Out-of-hospital patients in severe respiratory distress, with failing respiratory efforts, were eligible for the study. The study was approved under exception to informed consent guidelines. Patients were randomized to receive either usual care, including conventional medications plus oxygen by facemask, bag-valve-mask ventilation, or tracheal intubation, or conventional medications plus out-of-hospital CPAP. The primary outcome was need for tracheal intubation during the out-of-hospital/hospital episode of care. Mortality and length of stay were secondary outcomes of interest. RESULTS In total, 71 patients were enrolled into the study, with 1 patient in each group lost to follow-up after refusing full consent. There were no important differences in baseline physiologic parameters, out-of-hospital scene times, or emergency department diagnosis between groups. In the usual care group, 17 of 34 (50%) patients were intubated versus 7 of 35 (20%) in the CPAP group (unadjusted odds ratio [OR] 0.25; 95% confidence interval [CI] 0.09 to 0.73; adjusted OR 0.16; 95% CI 0.04 to 0.7; number needed to treat 3; 95% CI 2 to 12). Mortality was 12 of 34 (35.3%) in the usual care versus 5 of 35 (14.3%) in the CPAP group (unadjusted OR 0.3; 95% CI 0.09 to 0.99). CONCLUSION Paramedics can be trained to use CPAP for patients in severe respiratory failure. There was an absolute reduction in tracheal intubation rate of 30% and an absolute reduction in mortality of 21% in appropriately selected out-of-hospital patients who received CPAP instead of usual care. Larger, multicenter studies are recommended to confirm this observed benefit seen in this relatively small trial.

Air Versus Ground Transport of the Major Trauma Patient: A Natural Experiment

Abstract Objectives. 1) To compare the outcomes of adult trauma patients transported to a level I trauma center by helicopter vs. ground ambulance. 2) To determine whether using a unique “natural experiment” design to obtain the ground comparison group will reduce potential confounders. Methods. Outcomes in adult trauma patients transported to a tertiary care trauma center by air were compared with outcomes in a group of patients who were accepted by the online medical control physician for air transport, but whose air missions were aborted for aviation reasons (weather, maintenance, out on a mission); these patients were subsequently transported by ground ambulance instead. Outcomes were also analyzed for a third ground control group composed of all other adult trauma patients transported by ground during this time period. Data were collected by retrospective database review of trauma patients transferred between July 1, 1997, and June 30, 2003. Outcomes were measured by Trauma Injury Severity Score (TRISS) analysis. Z and W scores were calculated. Results. Three hundred ninety-seven missions were flown by LifeFlight during the study period vs. 57 in the clinical accept–aviation abort ground transport group. The mean ages, gender distributions, mechanisms of injury, and Injury Severity Scores (ISSs) were similar in the two groups. Per 100 patients transported, 5.61 more lives were saved in the air group vs. the clinical accept–aviation abort ground transport group (Z = 3.37). As per TRISS analysis, this is relative to the expected mortality seen with a similar group in the Major Trauma Outcomes Study (MTOS). The Z score for the clinical accept–aviation abort ground transport group was 0.4. The 1,195 patients in the third all-other ground control group had a higher mean age, lower mean ISS, and worse outcomes according to TRISS analysis (W = –2.02). Conclusions. This unique natural experiment led to better matched air vs. ground cohorts for comparison. As per TRISS analysis, air transport of the adult major trauma patient is associated with significantly improved survival as compared with ground transport.

Procedural sedation and analgesia in a Canadian adult tertiary care emergency department: a case series.

OBJECTIVES To examine the safety of emergency department (ED) procedural sedation and analgesia (PSA) and the patterns of use of pharmacologic agents at a Canadian adult teaching hospital. METHODS Retrospective analysis of the PSA records of 979 patients, treated between Aug. 1, 2004, and July 31, 2005, with descriptive statistical analysis. This represents an inclusive consecutive case series of all PSAs performed during the study period. RESULTS Hypotension (systolic blood pressure < or = 85 mm Hg) was documented during PSA in 13 of 979 patients (1.3%; 95% confidence interval [CI] 0.3%-2.3%), and desaturation (SaO2 < or = 90) in 14 of 979 (1.4%; Cl 0.1%-2.7%). No cases of aspiration, endotracheal intubation or death were recorded. The most common medication used was fentanyl (94.0% of cases), followed by propofol (61.2%), midazolam (42.5%) and then ketamine (2.7%). The most frequently used 2-medication combinations were propofol and fentanyl (P/F) followed by midazolam and fentanyl (M/F), used with similar frequencies 58.1% (569/979) and 41.0% (401/979) respectively. There was no significant difference in the incidence of hypotension or desaturation between the P/F and M/F treated groups. In these patients, 9.1% (90/979) of patients received more than 2 different drugs. CONCLUSIONS Adverse events during ED PSA are rare and of doubtful clinical significance. Propofol/fentanyl and midazolam/fentanyl are used safely, and at similar frequencies for ED PSA in this tertiary hospital case series. The use of ketamine for adult PSA is unusual in our facility.

Comparison of a nomogram and physician-adjusted dosage of warfarin for prophylaxis against deep-vein thrombosis after arthroplasty.

Background: Warfarin is an effective agent for prophylaxis against deep-vein thrombosis following total hip or knee arthroplasty. However, management with warfarin in the postoperative setting is problematic because of the need for anticoagulant monitoring. We developed a nomogram for the dosing of warfarin that was specific for joint arthroplasty. The objective of this study was to compare the performance of this nomogram with that of physician-adjusted dosing of warfarin for patients undergoing total hip or knee arthroplasty.Methods: The study involved two cohort trials. The historical control group consisted of 1024 patients who underwent total hip or knee arthroplasty during the course of a clinical trial (the Post-Arthroplasty Screening Study [PASS]) in which all warfarin dose adjustments were made by two hematologists. The first dose of warfarin was given on the evening of the surgery, and the warfarin dose was adjusted daily on the basis of the international normalized ratio and was discontinued at the time of discharge from the hospital. In the PASS study, the dosage of warfarin was designed to prolong the international normalized ratio to 1.7 by postoperative day 4 and to maintain it between 1.8 and 2.5 until discharge from the hospital. Subsequently, a warfarin nomogram was developed on the basis of the dose adjustments used in the PASS study, and it was used prospectively to manage a cohort of 729 patients undergoing total hip or knee arthroplasty. In the nomogram cohort, the initial dose of warfarin was given on the evening of the surgery. Both cohorts were followed for twelve weeks after the surgery to determine if any venous thromboembolic complications had developed.Results: The nomogram cohort and the control cohort had similar daily doses of warfarin (mean, 3.2 versus 3.3 mg) and levels of international normalized ratio on postoperative day 4 (mean, 1.9 versus 1.9) (p > 0.2). The average number of days to achieve an international normalized ratio of >1.7 was 4.0 for the nomogram cohort compared with 4.3 for the control cohort (p = 0.01). The percentage of days that the international normalized ratio was between 1.8 and 2.5 was 61% for the nomogram cohort and 58% for the control cohort (p < 0.01), and the percentage of days that the international normalized ratio was >3.0 was only 6.5% for the nomogram cohort and 6.0% for the control cohort (p > 0.2). Eighty-two percent of the patients managed with the nomogram achieved an international normalized ratio of >1.7 by the time of discharge from the hospital compared with 92% in the control cohort (p = 0.01). In the three-month follow-up period, a deep-vein thrombosis or a nonfatal pulmonary embolism developed in nineteen patients (2.6%; 95% confidence interval, 1.6% to 4.0%) in the nomogram cohort compared with fourteen patients (1.4%; 95% confidence interval, 0.7% to 2.3%) in the control cohort. No major bleeding event or fatal pulmonary embolism was observed in the patients managed with use of the nomogram.Conclusion: This study demonstrated that the administration of warfarin during hospitalization with use of a nomogram designed for the prevention of deep-vein thrombosis following total hip or knee arthroplasty provided effective and safe prophylaxis that was comparable with that provided by physician-adjusted dosing of warfarin.

Some basic biomechanical characteristics of medullary pressure generation during reaming of the femur

We measured femoral intramedullary pressures and applied axial thrust force generated in vitro during reaming with the AO and Zimmer systems. Six pairs of cadaver femora were instrumented with pressure taps midshaft and in the distal diaphysis, a load cell distally to measure force, and a displacement transducer to monitor reamer position. Following initial hand reaming, intramedullary power reaming was conducted utilizing a 9-mm reamer initially, with subsequent increases in steps of 0.5 mm. All femora were maintained at 37 degrees C and albumin was used to maintain a fluid-filled canal. The highest pressures consistently occurred during initial power reaming, with peak pressures ranging from 270 to 1500 mmHg amongst femora with the AO system. No significant differences were found in the peak pressures generated for the two systems (P = 0.10). The pressure measurements at the two locations in the femur were consistently similar, indicating that pressures are continuous throughout this aspect of the femur. The pressures were not correlated with instantaneous applied axial thrust (R2 = 0.191), and this could be attributed chiefly to the additional friction force of cutting. While pressure generation in the medullary canal upon reaming is likely governed by the rate of clearance of canal content, this is a highly variable response produced by characteristics of the femur which are still not fully understood.