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Biomedical subjects

Colin F Mackenzie

Publications and source records attributed to Colin F Mackenzie.

11 recordsLinked to original sources
PubMed2006

Mentors decrease compliance with best sterile practices during central venous catheter placement in the trauma resuscitation unit.

BACKGROUND: In the academic trauma unit during initial evaluation and resuscitation of trauma victims, central venous catheters are often placed by multiple operators. There are few data on compliance with accepted, standard sterile practices during such procedures. METHODS: Prospective data were tabulated from video capture of 144 consecutive central venous catheterizations in a trauma resuscitation unit, during peak hours, by a team of trained video technicians. The physicians were surgical and emergency medicine residents. The number of primary operators (trainees) and secondary operators (mentors) for each line was recorded from the video analysis, as well as physician adherence to the use of maximum barrier precautions (MBP; sterile gown, gloves, full operative drape, cap, and mask). Procedures were stratified by level of urgency: Emergent (n = 7), semi-emergent (n = 20), and elective (n = 113). RESULTS: The subclavian vein was used for 73% of the elective catheter placements. For elective central venous catheters, 99 of 113 primary operators (88%) observed MBP, whereas only 31 of 45 secondary operators (69%) did so (p < or = 0.01). Among the 45 elective central venous catheters placed with a secondary operator, there were four instances of frank contamination (9%). CONCLUSIONS: Secondary operators, typically trauma surgery attendings, trauma/critical care fellows, or senior surgical residents, function as mentors in academic institutions and act as role models. Secondary operators participated in many of the studied cases, yet failed to demonstrate consistent use of MBP. In elective central venous catheter placement, those where there was the greatest opportunity to follow MBP, we observed a statistically significant difference in compliance rate between the primary and secondary operators. The study suggests the need to address the performance of the secondary operators and to educate them, as although they may be technically experienced in placing central venous catheters, they may comply less consistently with MBP.

Catheterization, Central Venous↗
PubMed2006

Video-based ergonomic analysis to evaluate thoracostomy tube placement techniques.

BACKGROUND: Thoracostomy for relief of pneumo- or hemothorax may be performed emergently at the bedside, in the emergency department or trauma area, often in nonideal circumstances. We hypothesized that ergonomic analysis of thoracostomy techniques can identify areas for potential improvement in patient and operator safety. METHODS: Interviews with Subject Matter Experts (SME) provided steps in the task of thoracostomy; 44 thoracostomies (emergent and elective) were video-recorded and reviewed by SMEs. Ergonomic analyses evaluated surgical performance techniques using video clips. RESULTS: Risks to the patient and operator included instrument-tray positioning and instrument content. Analyses of video records revealed that despite SME-survey consensus, operators inconsistently followed recommended techniques. CONCLUSIONS: Discrepancies between SME-recommended and observed practice are prevalent, with simple ergonomic problems impeding performance, and creating risks for patients and operators. Video-based ergonomic analysis is a rich source for identifying task performance problems and potential solutions.

Chest Tubes↗
PubMed2006

Trauma reception and resuscitation.

The hospital reception phase of major trauma management requires a great number of expedient decisions. However, despite widely taught programmes advocating a standardized, algorithmic approach to decision-making, there is an ongoing rate of human errors contributing to adverse outcomes. It is now time for a fundamental change in our approach to trauma resuscitation. Point-of-care computer technology linked to real-time decision-making and trauma team coordination may achieve error reduction through standardized decision-making and a corresponding reduction in preventable mortality and morbidity.

Algorithms↗
PubMed2005

An algorithm for processing vital sign monitoring data to remotely identify operating room occupancy in real-time.

We developed an algorithm for processing networked vital signs (VS) to remotely identify in real-time when a patient enters and leaves a given operating room (OR). The algorithm addresses two types of mismatches between OR occupancy and VS: a patient is in the OR but no VS are available (e.g., patient is being hooked up), and no patient is in the OR but artifactual VS are present (e.g., because of staff handling of sensors). The algorithm was developed with data from 7 consecutive days (122 cases) in a 6 OR trauma center. The algorithm was then tested on data from another 7 consecutive days (98 cases), against patient in- and out-times captured by OR surveillance videos. When pulse oximetry, electrocardiogram, and temperature readings were used, OR occupancy was correctly identified 96% (95% confidence interval [CI] 95%-97%) and OR vacancy >99% of the time. Identified patient in- and out-times were accurate within 4.9 min (CI 4.2-5.7) and 2.8 min (CI 2.3-3.5), respectively, and were not different in accuracy from times reported by staff on OR records. The algorithm's usefulness was demonstrated partly by its continued operational use. We conclude that VS can be processed to accurately report OR occupancy in real-time.

Algorithms↗
PubMed2004

Hemoglobin substitutes.

Orthopaedic patients frequently require blood transfusions to treat peri-operative anemia. Research in the area of hemoglobin substitutes has been of great interest since it holds the promise of reducing the reliance on allogeneic blood transfusions. The three categories of hemoglobin substitutes are (1) cell-free, extracellular hemoglobin preparations made from human or bovine hemoglobin (hemoglobin-based oxygen carriers or HBOCs); (2) fluorine-substituted linear or cyclic carbon chains with a high oxygen-carrying capacity (perfluorocarbons); and (3) liposome-encapsulated hemoglobin. Of the three, HBOCs have been the most extensively studied and tested in preclinical and clinical trials that have shown success in diminishing the number of blood transfusions as well as an overall favorable side-effect profile. This has been demonstrated in vascular, cardiothoracic, and orthopaedic patients. HBOC-201, which is a preparation of cell-free bovine hemoglobin, has been approved for clinical use in South Africa. These products may well become an important tool for physicians treating peri-operative anemia in orthopaedic patients.

Anemia↗
PubMed2004

Artificial oxygen carriers for trauma: myth or reality.

Two-unit blood transfusion accounts for one third of blood use in trauma patients. Artificial oxygen carriers have no need for cross-match, allow volume expansion, prolonged storage at 1-38 degrees C, and improve rheology to reverse ischaemia. Haemoglobin-based oxygen carriers can provide a vital alternative given the predicted future shortfall in blood donations.

Anemia↗
PubMed2002

Hypotensive resuscitation during active hemorrhage: impact on in-hospital mortality.

BACKGROUND: Traditional fluid resuscitation strategy in the actively hemorrhaging trauma patient emphasizes maintenance of a normal systolic blood pressure (SBP). One human trial has demonstrated improved survival when fluid resuscitation is restricted, whereas numerous laboratory studies have reported improved survival when resuscitation is directed to a lower than normal pressure. We hypothesized that fluid resuscitation titrated to a lower than normal SBP during the period of active hemorrhage would improve survival in trauma patients presenting to the hospital in hemorrhagic shock. METHODS: Patients presenting in hemorrhagic shock were randomized to one of two fluid resuscitation protocols: target SBP > 100 mm Hg (conventional) or target SBP of 70 mm Hg (low). Fluid therapy was titrated to this endpoint until definitive hemostasis was achieved. In-hospital mortality, injury severity, and probability of survival were determined for each patient. RESULTS: One hundred ten patients were enrolled over 20 months, 55 in each group. The study cohort had a mean age of 31 years, and consisted of 79% male patients and 51% penetrating trauma victims. There was a significant difference in SBP observed during the study period (114 mm Hg vs. 100 mm Hg, p < 0.001). Injury Severity Score (19.65 +/- 11.8 vs. 23.64 +/- 13.8, p = 0.11) and the duration of active hemorrhage (2.97 +/- 1.75 hours vs. 2.57 +/- 1.46 hours, p = 0.20) were not different between groups. Overall survival was 92.7%, with four deaths in each group. CONCLUSION: Titration of initial fluid therapy to a lower than normal SBP during active hemorrhage did not affect mortality in this study. Reasons for the decreased overall mortality and the lack of differentiation between groups likely include improvements in diagnostic and therapeutic technology, the heterogeneous nature of human traumatic injuries, and the imprecision of SBP as a marker for tissue oxygen delivery.

Adult↗
PubMedDate not supplied

The informatics response in disaster, terrorism, and war.

The United States currently faces several new, concurrent large-scale health crises as a result of terrorist activity. In particular, three major health issues have risen sharply in urgency and public consciousness--bioterrorism, the threat of widespread delivery of agents of illness; mass disasters, local events that produce large numbers of casualties and overwhelm the usual capacity of health care delivery systems; and the delivery of optimal health care to remote military field sites. Each of these health issues carries large demands for the collection, analysis, coordination, and distribution of health information. The authors present overviews of these areas and discuss ongoing work efforts of experts in each.

Bioterrorism↗