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Featured researches published by David S. Mulder.


Journal of Trauma-injury Infection and Critical Care | 1999

Trauma care regionalization: a process-outcome evaluation.

John S. Sampalis; Ronald Denis; André Lavoie; Pierre Frechette; Stella Boukas; Andreas Nikolis; Daniel Benoit; David Fleiszer; Rea A. Brown; Micheal Churchill-Smith; David S. Mulder

BACKGROUND Regionalization of trauma care services in our region was initiated in 1993 with the designation of four tertiary trauma centers. The process continued in 1995 with the implementation of patient triage and transfer protocols. Since 1995, the network of trauma care has been expanded with the designation of 33 secondary, 30 primary, and 32 stabilization trauma centers. In addition, during this period emergency medical personnel have been trained to assess and triage trauma victims within minimal prehospital time. The objective of the present study was to evaluate the impact of trauma care regionalization on the mortality of major trauma patients. METHODS This was a prospective study in which patients were entered at the time of injury and were followed to discharge from the acute-care hospital. The patients were identified from the Quebec Trauma Registry, a review of the records of acute-care hospitals that treat trauma, and records of the emergency medical services in the region. The study sample consisted of all patients fulfilling the criteria of a major trauma, defined as death, or Injury Severity Score (ISS) > 12, or Pre-Hospital Index > 3, or two or more injuries with Abbreviated Injury Scale scores > 2, or hospital stay of more than 3 days. Data collection took place between April 1, 1993, and March 31, 1998. During this period, four distinct phases of trauma care regionalization were defined: pre-regionalization (phase 0), initiation (phase I), intermediate (phase II), and advanced (phase III). RESULTS A total of 12,208 patients were entered into the study cohort, and they were approximately evenly distributed over the 6 years of the study. During the study period, there was a decline in the mean age of patients from 54 to 46 years, whereas the male/female ratio remained constant at 2:1. There was also an increase in the mean ISS, from 25.5 to 27.5. The proportion of patients injured in motor vehicle collisions increased from less than 45% to more than 50% (p < 0.001). The mortality rate during the phases of regionalization were: phase 0, 52%; phase I, 32%; phase II, 19%; and phase III, 18%. These differences were clinically important and statistically significant (p < 0.0001). Stratified analysis showed a significant decline in mortality among patients with ISS between 12 and 49. The change in mortality for patients with fatal injuries (ISS > or = 50) was not significant. During the study period, the mean prehospital time decreased significantly, from 62 to 44 minutes. The mean time to admission after arrival at the hospital decreased from 151 to 128 minutes (p < 0.001). The latter decrease was primarily attributable to changes at the tertiary centers. The proportion of patients with ISS between 12 and 24 and between 25 and 49 who were treated at tertiary centers increased from 56 to 82% and from 36 to 84%, respectively (p < 0.001). Compared with the secondary and primary centers, throughout the course of the study the mortality rate in the secondary and tertiary centers showed a consistent decline (p < 0.001). In addition, the mortality rate in the tertiary centers remained consistently lower (p < 0.001). The results of multivariate analyses showed that after adjusting for injury severity and patient age, the primary factors contributing to the reduced mortality were treatment at a tertiary center, reduced prehospital time, and direct transport from the scene to tertiary centers. CONCLUSION This study produced empirical evidence that the integration of trauma care services into a regionalized system reduces mortality. The results showed that tertiary trauma centers and reduced prehospital times are the essential components of an efficient trauma care system.


Journal of Trauma-injury Infection and Critical Care | 2000

Advanced or basic life support for trauma: meta-analysis and critical review of the literature.

Moishe Liberman; David S. Mulder; John S. Sampalis

BACKGROUND The question of whether to use advanced life support (ALS) or basic life support (BLS) for trauma patients in the prehospital setting has been much debated and still lacks a clear answer. The purpose of this study was to conduct a comprehensive critical review of the literature regarding this controversy METHODS A total of 174 articles on prehospital ALS or BLS for trauma were reviewed. Fifteen of these studies were found to involve mortality statistics for both ALS- and BLS-treated patients. Odds ratios were calculated for survival in ALS versus BLS and summarized across studies on the basis of multivariate scoring systems that incorporated both design and methodological assessment. Overall odds ratios for all studies were calculated on the basis of both raw data from the papers, and weighted odds ratios were calculated from the scoring systems. RESULTS Six studies were scored as being methodologically average (5 favoring BLS and 1 favoring ALS), two were scored as good (1 favoring BLS and 1 favoring ALS), seven as excellent (6 favoring BLS and 1 favoring ALS). Ten studies had an average study design score (6 favoring BLS and 4 favoring ALS) and seven had a good study design score (6 favoring BLS and 1 favoring ALS). Weighted odds ratio for dying was 2.59 for patients receiving ALS compared with those receiving BLS. The crude odds ratio was 2.92. CONCLUSION The aggregated data in the literature have failed to demonstrate a benefit for on-site ALS provided to trauma patients and support the scoop and run approach.


Journal of Trauma-injury Infection and Critical Care | 1997

Direct transport to tertiary trauma centers versus transfer from lower level facilities: impact on mortality and morbidity among patients with major trauma

John S. Sampalis; Ronald Denis; Pierre Frechette; Rea A. Brown; David Fleiszer; David S. Mulder

BACKGROUND The purpose of the study was to compare the outcome of severely injured patients who were transported directly to a Level I, tertiary trauma center with those who were transferred after being first transported to less specialized hospitals. METHODS The data were based on all patients treated at three tertiary trauma centers in Quebec between April 1, 1993, and December 31, 1995. There were 1,608 patients (37%) transferred and 2,756 patients (63%) transported directly. RESULTS The mean age of the patients was approximately 45 years, and more than 60% were males. The predominant mechanisms of injury were falls and motor vehicle crashes. The transfer and direct transport groups were similar with respect to age, gender, and mechanism of injury. Body regions injured were also similar with the exception of head or neck injuries (transfer, 56%; direct, 28%; p < 0.0001). The mean Injury Severity Score was 14, the mean Pre-Hospital Index score was 5.5, and the mean Revised Trauma Score was 7.5. The two groups were similar with respect to these injury severity measures. The primary outcome of interest was mortality described as overall death rate, death rate in the emergency room, and death rate after admission. Other outcomes studied were hospital length of stay and duration of treatment in an intensive care unit. When compared with the direct transport group, transferred patients were at increased risk for overall mortality (transfer, 8.9%; direct, 4.8%; odds ratio, 1.96; 95% confidence interval (CI) = 1.53-2.50), emergency room mortality (transfer, 3.4%; direct, 1.2%; odds ratio, 2.96; 95% CI = 1.90-4.6), and mortality after admission (transfer, 5.5%; direct, 3.6%; odds ratio, 1.57; 95% CI = 1.17-2.11). All of these differences were statistically significant (p < 0.003). Stratified and multiple logistic regression analysis did not alter these results and failed to identify a patient subgroup for which transfer was associated with a reduced risk of mortality. After adjusting for patient age, Injury Severity Score, and presence of injuries to the head or neck and extremities, transferred patients stayed significantly longer in the hospital and the intensive care unit as indicated by the mean length of stay (transfer, 16.0 days; direct, 13.2 days; p = 0.02) and the mean intensive care unit stay (transfer, 2.0 days; direct, 0.95 days; p = 0.001). CONCLUSION The results of this study have shown that transportation of severely injured patients from the scene directly to Level I trauma centers is associated with a reduction in mortality and morbidity. Further studies are required for the evaluation of transport protocols for rural trauma. Economic and cost-effectiveness considerations of patient triage are also essential.


Journal of Trauma-injury Infection and Critical Care | 1993

Impact of on-site care, prehospital time, and level of in-hospital care on survival in severely injured patients

John S. Sampalis; André Lavoie; Jack I. Williams; David S. Mulder; Mathias Kalina

A sample of 360 severely injured patients was selected from a cohort of 8007 trauma victims followed prospectively from the time of injury to death or discharge. A case referent study was used to test the association between on-site care, total prehospital time, and level of care at the receiving hospital with short-term survival. Multiple logistic regression analyses showed that use of Advanced Life Support (ALS) at the scene was not associated with survival, whereas treatment at a level I compatible hospital was associated with a 38% reduction in the odds of dying, which approached statistical significance. Total prehospital time over 60 minutes was associated with a statistically significant adjusted relative odds of dying (OR = 3.0). The results of this study support the need for regionalization of trauma care and fail to show a benefit associated with ALS.


Journal of Trauma-injury Infection and Critical Care | 1990

Endoscopic guided percutaneous tracheostomy: early results of a consecutive trial.

D. Marelli; A. Paul; S. Manolidis; G. Walsh; J. N. K. Odim; T. A. Burdon; Hani Shennib; K.-H. Vestweber; D. M. Fleiszer; David S. Mulder

Percutaneous tracheostomy is increasingly being used for patients needing prolonged ventilatory support. The purpose of this study was to assess the feasibility of widespread application of endoscopic guided percutaneous tracheostomy. Sixty-one consecutive ICU patients requiring prolonged mechanical ventilation underwent bedside endoscopic guided percutaneous tracheostomy. Using a modified Ciaglia technique, a #6-10 tracheostomy tube was introduced between the second and third tracheal rings. Bronchoscopic transillumination facilitated identification of the appropriate tracheostomy site, and verified satisfactory placement of dilators and tracheostomy tube. There was one procedure-related death due to arrhythmia. Procedure-related complications included (n = 7): bleeding (controlled with local pressure), two infections, two cuff tears, and two obstructions of the tracheal tube. The tracheostomy was eventually removed in 13 patients. Bronchoscopic evaluation of three patients at 4 months post-tracheostomy removal was normal and there has been no clinical evidence suggestive of tracheal stenosis in the remaining ten extubated patients. There was a 50% reduction in cost when compared to operative tracheostomy. Percutaneous tracheostomy is a simple, safe, cost-effective bedside procedure for critically ill ventilator-dependent patients. Endoscopic guidance appears to increase the safety of this procedure and may prevent complications of pneumothorax, subcutaneous emphysema, and paratracheal false passage previously reported with blinded percutaneous methods.


Pain | 1987

Pain on a surgical ward: a survey of the duration and intensity of pain and the effectiveness of medication

Ronald Melzack; Frances V. Abbott; Warren Zackon; David S. Mulder; M. William; L. Davis

&NA; The effectiveness of analgesic medication for post‐surgical pain was surveyed in a surgical ward of a large general hospital. Since earlier studies have shown that pain generally decreases rapidly and is negligible by the fourth day after surgery, the patients in the survey were assigned to 2 groups: (1) those given analgesics during the first 4 days after surgery, and (2) those given analgesics for pain after the fourth day. The results show that the patients with pain that persists beyond day 4 comprise a substantial proportion of the patients in a surgery ward (31%), are older, tend to use more words to describe their pain, and are helped less by their prescribed analgesic medications. This group is prescribed lower doses of analgesics and receives them more frequently; however, this prescription strategy appears to be ineffective since 26% of these patients report increased pain after medication compared to only 2% in the group that received analgesics during the first 4 days.


Annals of Surgery | 2003

Multicenter Canadian Study of Prehospital Trauma Care

Moishe Liberman; David S. Mulder; André Lavoie; Ronald Denis; John S. Sampalis

ObjectiveTo evaluate whether the type of on-site care a trauma patient receives affects outcome. Summary Background DataThe controversy regarding the prehospital care of trauma patients between Advanced Life Support (ALS) and Basic Life Support (BLS) is ongoing. Due to this unresolved controversy, as well as historical, cultural, and political factors, there are significant variations with respect to the type of prehospital care available for trauma patients. MethodsThis prospective cohort study compared three types of prehospital trauma care systems: Montreal, where physicians provide ALS (MD-ALS); Toronto, where paramedics provide ALS (PMD-ALS); and Quebec City, where emergency medical technicians provide BLS only (EMT-BLS). The study took advantage of this variation to evaluate the association between the type of on-site care and mortality in patients with major life-threatening injuries. All patients were treated at highly specialized tertiary (level I) trauma hospitals. The main outcome measure was death as a result of injury. Follow-up was to hospital discharge. ResultsThe overall mortality rates by type of on-site personnel were physicians 35%, paramedics 24%, and EMTs 18%. For patients with major but survivable trauma, the overall mortality rates were physicians 32%, paramedics 28%, and EMTs 26%. The overall mortality rate of patients receiving only BLS at the scene was 18% compared to 29% for patients receiving ALS. For the subgroup of patients with major but survivable injuries, the mortality rates were 30% for ALS and 26% for BLS. The adjusted increased risk for mortality in patients receiving ALS at the scene was 21%. ConclusionsIn urban centers with highly specialized level I trauma centers, there is no benefit in having on-site ALS for the prehospital management of trauma patients.


Journal of Trauma-injury Infection and Critical Care | 1994

Trauma center designation: Initial impact on trauma-related mortality

John S. Sampalis; André Lavoie; S. Boukas; Hala Tamim; A. Nikolis; Pierre Frechette; R. Brown; D. M. Fleiszer; R. Denis; Eric Bergeron; David S. Mulder; D. D. Trunkey; J. S. Smith; A. B. Eastman; J. Hammond; P. Angood; M. L. Hawkins; J. A. Mendelson; C. G. Cayten; R. S. Smith

The movement towards trauma care regionalization in Québec was initiated in 1990, with formal designation of three level I trauma centers in 1993. The purpose of this study is to evaluate the impact of trauma center designation on mortality. The study design is that of a two-cohort study, one assembled during 1987 when designation was not in effect, and the other during the first 5 months of designation. The study focuses on patients that fulfilled the following criteria: i) arrived alive at the hospital, and ii) were admitted. The outcome measures are adjusted mortality, and excess mortality as measured by the TRISS methodology. A total of 158 patients treated in 1987, and 288 treated in 1993, were identified. The mean age of the patients treated in 1993 was significantly higher (40.0, +/- 18.1), when compared with the 1987 group (30.9 +/- 18.1; p < 0.001). Patients in the 1987 cohort had a significantly higher proportion of injuries caused by stabbing (p = 0.02), and a significantly lower proportion caused by falls (p = 0.003). The 1987 cohort had a higher rate of abdominal injuries (p = 0.0001), and external injuries (p = 0.0001), and a significantly lower rate of head or neck injuries (p = 0.003), and injuries to the extremities (p = 0.0001). The mean Injury Severity Score (ISS) for the 1987 cohort was 14.96 (+/- 12.36), and 15.49 (+/- 11.61) in 1993 (p = 0.65). The crude mortality rate was 20% for 1987, and 10% for 1993. The crude odds ratio for mortality in 1987 was 2.10 with 95% confidence intervals between 1.22 and 3.62 (p = 0.006).(ABSTRACT TRUNCATED AT 250 WORDS)


Journal of Trauma-injury Infection and Critical Care | 1997

Ineffectiveness of on-site intravenous lines: is prehospital time the culprit?

John S. Sampalis; Hala Tamim; Ronald Denis; Stella Boukas; Sebastien-Abel Ruest; Andreas Nikolis; André Lavoie; David Fleiszer; Rea A. Brown; David S. Mulder; Jack I. Williams

The purpose of the present study was to test the association between on-site intravenous fluid replacement and mortality in patients with severe trauma. The effect of prehospital time on this association was also evaluated. The design was that of an observational quasi-experimental study comparing 217 patients who had on-site intravenous fluid replacement (IV group) with an equal number of matched patients for whom this intervention was not performed (no-IV group). The patients were individually matched on their Prehospital Index obtained at the scene and were included in the study if they had an on-site Prehospital Index score > 3 and were transported alive to the hospital. The outcome measure of interest was mortality because of injury. The patients in the IV group had a significantly lower mean age (37 vs. 45 years; p < 0.001) and higher incidence of injuries to the head or neck (46 vs. 32%; p = 0.004), chest (34 vs. 17%; p < 0.001), and abdomen (28 vs. 12%; p < 0.001). The IV group also had a higher proportion of patients injured by motor vehicle crashes (41 vs. 27%; p = 0.003), firearms (9 vs. 2%; p = 0.001), and stabbing (20 vs. 9%; p = 0.001). The rate of extremity injuries (38 vs. 59%; p < 0.001) and falls (12 vs. 40%; p < 0.001) was lower for the IV group. In addition, the mean Injury Severity Score was significantly higher for the IV group (15 vs. 9; p < 0.001). The mortality rates for the IV and no-IV groups were 23 and 6% (p < 0.001). Logistic regression analysis showed that after adjusting for patient age, gender, Injury Severity Score, mechanism of injury, and prehospital time, the use of on-site intravenous fluid replacement was associated with a significant increase in the risk of mortality (adjusted odds ratio = 2.3; 95% confidence interval = 1.02-5.28; p = 0.04). To further evaluate the effect of prehospital time on the association between on-site IV use and mortality, the analysis was repeated separately for the following time strata: 0 to 30 minutes, 31 to 60 minutes, and >60 minutes. The adjusted odds ratios (95% confidence interval) for these strata were 1.05 (0.08-14.53; p = 0.97), 3.38 (0.84-13.62; p = 0.08), and 8.40 (1.27-54.69; p = 0.03). These results show that for prehospital times of less than 30 minutes, the use of on-site intravenous fluid replacement provides no benefit, and that for longer times, this intervention is associated with significant increases in the risk of mortality. The results of this observational study have shown that the use of on-site intravenous fluid replacement is associated with an increase in mortality risk and that this association is exacerbated by, but is not solely the result of, increased prehospital times. Our findings are consistent with the hypothesis that early intravenous fluid replacement is harmful because it disrupts the normal physiologic response to severe bleeding. Although this evidence is against the implementation of on-site intravenous fluid replacement for severely injured patients, further studies including randomized controlled trials are required to provide a definitive answer to this question.


The Annals of Thoracic Surgery | 1989

Percutaneous endoscopic tracheostomy

A. Paul; D. Marelli; Ray C.-J. Chiu; K.H. Vestweber; David S. Mulder

Bedside percutaneous tracheostomies are increasingly performed. This avoids patient transport to the operating room. Complications of this procedure are largely related to the blind nature of the technique. After laboratory studies, 4 patients underwent percutaneous endoscopic guided tracheostomy in a selective clinical trial. There were no procedure-related complications. Endoscopic guidance ensures precise low tracheostomy position, prevents paratracheal tube misplacement, and avoids inadvertent injuries.

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Rea A. Brown

Montreal General Hospital

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David Fleiszer

Montreal General Hospital

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Moishe Liberman

Montreal General Hospital

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Ronald Denis

Université de Montréal

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