Association between outcome, cerebral pressure reactivity and slow ICP waves following head injury

OBJECTIVE

To investigate the relationships between slow vasogenic waves ('B waves') of intracranial pressure (ICP), pressure-reactivity and outcome after traumatic brain injury.

MATERIAL AND METHOD

193 head-injured patients (age 34 +/- 16.7 years; median GCS 6) were monitored from 1997 to 2002. ICP, arterial blood pressure (ABP) were continuously monitored. Pressure-reactivity index (PRx) and magnitude of ICP slow waves were evaluated using the bed-side computers.

RESULTS

Distribution of PRx in different outcome groups indicated that pressure-reactivity was significantly worse in patients with fatal outcome. A magnitude of spontaneous slow waves of ICP was gradually decreasing in poorer outcome grades. Mortality indicated threshold rise from 20% to 70% when averaged PRx increased above 0.3 (p < 0.01). There was no threshold for mortality observed along distribution of magnitude of ICP slow waves. Mortality gradually increased when the magnitude of slow waves decreased (R = -0.26; p < 0.0001).

CONCLUSION

Inadequate pressure-reactivity and low magnitude of slow vasogenic waves of ICP are associated with fatal outcome after head injury. Based on brain monitoring data, differentiation between favourable outcome and severe disability is more problematic than differentiation between survivors and non-survivors.

Raised intracranial pressure and seizures in the neurological intensive care unit

BACKGROUND

The relationship between changes in intracranial pressure and incidence of subclinical seizures in patients requiring neurological intensive care is not fully understood. The aim of this study was to investigate if acute increases in intracranial pressure were accompanied by subclinical seizures.

METHODS

We prospectively studied 17 intensive care patients (11 male, aged 3-66 yr) who were selected from 85 patients requiring intracranial pressure measurement. Patients were selected to have a 30 min, 16-channel electroencephalogram (EEG) recorded when intracranial pressure remained increased despite preliminary treatments.

RESULTS

Diagnoses included head injury, intracranial haemorrhage, subarachnoid haemorrhage and sagittal sinus thrombosis. All patients had at least one acute episode of intracranial pressure increase. Pressures ranged from 90 to 440 mm H(2)O. Encephalopathic features (delta/theta rhythms and burst suppression) were noted on all EEGs. No seizure activity was recorded.

CONCLUSIONS

We conclude from this pilot study that seizures are an uncommon cause of acute raised intracranial pressure. To determine whether raised intracranial pressure causes seizures, long-term monitoring in a large cohort of intensive care patients would be necessary, studying patients with similar diagnoses and ages.

Prospective randomised trial comparing traditional suture technique with the dynamic sliding loop suture technique in the closure of skin lacerations

OBJECTIVE

The aim of this study was to compare the cosmetic appearance and related complications of selected skin lacerations closed by traditional suture technique with that of the dynamic sliding loop suture technique.

DESIGN

Prospective, randomised clinical trial.

SETTING

A district general hospital.

PARTICIPANTS

Thirty seven eligible patients aged between 16 and 60 years with skin lacerations (no deeper than superficial fascia) to the limbs, trunk, and neck (excluding face and scalp) and with no associated neurovascular or tendon injuries were recruited into the trial. The exclusion criteria used included immunocompromised patients (diabetics, malignancy, renal failure, corticosteroid treatment), primary dermatological conditions (psoriasis, eczema), keloid prone or susceptible patients, and wounds judged unsuitable for primary closure.

INTERVENTION

Skin lacerations were randomly allocated to have closure by either the traditional method or by use of the dynamic sliding loop suture method. The trial had ethical approval of the hospital ethics committee and all participants were fully informed of the trial both verbally and by an information leaflet. Written informed consent was obtained before starting the study.

MAIN OUTCOME MEASURE

The cosmetic appearance of photographs of wounds immediately after suture removal and at three months were assessed by a general surgeon and an orthopaedic surgeon blinded to the technique used. The 10 point visual analogue cosmesis scale was used for scoring the appearance of the wounds.

SECONDARY OUTCOME MEASURE

The presence of wound closure related complications such as infection, dehiscence, suture slippage, wound edge submergence, skin edge necrosis, and haematoma formation were noted and recorded on follow up visits.

RESULTS

A total of 37 patients participated in the trial over a period of 18 months. Seventeen patients underwent suture by the traditional technique and 20 by the dynamic sliding loop suture technique. Four patients (all from the traditional group) were lost to follow up and not included in the study. Most wounds healed uneventfully although there was one case of wound infection in each group. Four patients had ligature slippage (three from the dynamic suture and one from the traditional group). Two patients had evidence of skin edge necrosis both from the traditional technique group. A comparison of the healed wounds by two independent assessors blinded to the technique used showed no statistically significant difference observed between the two types of intervention (Wilcoxon matched paired test p>0.05) immediately after suture removal or at three months. Although there was no statistically demonstrable difference, the comparative paired absolute visual analogue scores seemed to consistently show higher values for the sliding loop technique.

CONCLUSION

The cosmetic appearance of wounds sutured using the dynamic sliding loop suture technique in this study were not statistically shown to be superior to those sutured using the traditional suture technique although absolute visual analogue scores consistently showed higher values for the sliding loop technique. The significance of this is unclear and may warrant a much larger trial to see if it is a trend that a larger population of participants can help to support or refute with regard to the superiority of this new technique.

The science of health technology assessment--the economic perspective

Economic evaluation is a component of health technology assessment. Methods for economic evaluation began to be developed about 30 years ago. More recently, governments have encouraged the development of methodological and reporting guidelines for economic evaluation in health care with the major focus being placed on pharmaceutical products. There are two aspects of economic evaluations discussed in the present paper: the science of the techniques used and the utility of the resulting evaluations. Although activity is increasing in this area, it is still not clear how useful such 'value for money' evaluations have actually been and how much they have been used. It seems that the 'value for money' of 'value for money' evaluations of pharmaceutical products has yet to be shown.

Bifrontal decompressive craniectomy in the management of posttraumatic intracranial hypertension

Bifrontal decompressive craniectomy has been used on an ad hoc basis for the treatment of post-traumatic intracranial hypertension for more than thirty years. In this observational study we report the clinical outcome and physiological effects of the procedure in a series of 26 patients with refractory intracranial hypertension treated on a protocol driven basis. Bifrontal decompressive craniectomy was associated with significant reductions in mean ICP from 37.5 to 18.1 mmHg (p = 0.003). In addition, craniectomy reduced the amplitude of ICP waves (p < 0.02) and increased compensatory reserve (p < 0.05). A favourable outcome was achieved in 69% of patients; 8% were severely disabled and 23% died. We conclude that this study provides pathophysiological evidence that bifrontal decompressive craniectomy significantly reduces posttraumatic intracranial hypertension and improves pressure dynamics. Our results support the continued use of bifrontal decompressive craniectomy in selected patients after head injury.

Application of strengths, weaknesses, opportunities and threats analysis in the development of a health technology assessment program

There has been recent interest in developing a health technology assessment (HTA) function in Estonia. A group of individuals knowledgeable about HTA in Canada, Germany, Romania and Spain, along with representatives of the University of Tartu, Estonia, was convened by the Institute of Health Economics in Edmonton, Canada, to consider options for such a function. In a one-day workshop strengths, weaknesses, opportunities and threats (SWOT) analyses of HTA were conducted, first at a 'global' level, and then of the Estonian situation. The 'global' SWOT analysis yielded a large number of items that pertain to institutionalized HTA in a generic sense, i.e. not based on any individual HTA agency. The 'Estonian' SWOT yielded a subset of items, which pertain to development of HTA in that country. Ten actionable steps were then developed on the basis of this subset, which could be used to initiate the creation of an HTA body in Estonia.

Inter-provincial variation in government drug formularies

In Canada, coverage for ambulatory prescription drug expenditures is provided to some groups by provincial drug plans through a provincial formulary. Little is known about the drugs provincial formularies give access to. We report the variation in availability of new drug molecules (NDM) across provincial formularies. We identified 108 NDM approved in Canada between 1991 and 1998. From each drug plan bulletin or formulary, we abstracted names of NDM listed as per 15 January 1999. We compared the level of listing across provinces using kappa coefficients. In the Quebec, BC, Manitoba and Saskatchewan formularies, more than 70% of the NDM were listed. In four provinces, this proportion was lower than 50%. In general, the agreement between formularies was poor. There is a wide variation across provinces in terms of NDM listed in the formularies. This variation reflects inter-provincial differences in the way drugs are selected for coverage.

Pharmaceutical cost control in Canada: does it work?

Governments in Canada have instituted mechanisms intended to control drug prices. These include the establishment of a semi-judicial body by the federal government to control factory-gate prices and of various measures at the provincial level, such as formulary management, use of generics, reference-based pricing, price freezes, and limits on markups. To a large extent, these measures have been effective in price control. Total drug spending in the country continues to rise, however; clearly, mechanisms other than price controls will need to be developed if drug spending is to be better managed.

Increased myeloperoxidase index and large unstained cell values can predict the neutropenia phase of cancer patients treated with standard dose chemotherapy

OBJECTIVE

The objective of this study was to better understand neutropenia induced by standard dose chemotherapy and to verify if there are any hematological parameters for defining the phase and possibly the duration of neutropenia.

METHODS

The kinetics of large unstained cells (LUCs) and lymphocytes was evaluated in 324 blood counts of 56 chemotherapy cycles through the use of a Technicon H2 or an ADVIA 120 hematology analyzer. Blood samples collected during the neutropenia phase were also studied by flow cytometry using a large panel of monoclonal antibodies. Parametric and nonparametric statistics were employed to compare the different variables analyzed. A linear regression between each variable before and after nadir and a simple linear correlation among the same variables in the neutropenic and recovery phase were performed.

RESULTS

The percentage of LUCs reaches the higher value at nadir and the difference between the mean value of prenadir and nadir is statistically significant (P <.01). The number of LUCs increases during the pre and postnadir phase. Lymphocytes number appears stable in the prenadir phase. The MPXI index increases in the prenadir phase and falls at nadir and this difference is statistically significant(P <.01). LUCs are correlated with blasts and CD34+ cells in the pre and postnadir phase, with CD3+/CD4+ cells in the prenadir phase, and with CD2+/CD56+ in the postnadir phase.

CONCLUSIONS

Our data have shown that the estimation of both percentage of LUCs and MPXI can predict the neutropenia phase and orient for its duration. The lymphocyte number may be regarded as a parameter of risk of fever after day 5 of chemotherapy and the number of blood CD34+ cells may be predicted by LUC count.

Health technology assessment in Canada. A decade in review

OBJECTIVES

Since 1988, four government-funded health technology assessment (HTA) agencies have been established in Canada. This paper is a descriptive review of reports issued by these organizations during the period from 1988 to 1998.

METHODS

Publications from the national and three provincial HTA agencies in Canada were obtained and reviewed. Only the 117 assessment reports that were reported to have undergone external review were included in this analysis. Each report was classified on a standard abstraction form according to criteria such as technology type(s), assessment focus, whether a specific policy question was clearly stated and relevant decision maker(s) identified, description of search strategy and selection criteria, sources of data and assessment methods used, whether recommendations or conclusions were made, and duplication or overlap of reports. The trends in these qualities over the 10-year period were also examined.

RESULTS

Therapeutic technologies have received the most attention from all four agencies, although the focus on devices, drugs, and procedures varied between agencies. The policy question under investigation was clearly identified in 82% of reports, and 71% clearly identified the decision maker toward whom the assessment was targeted. Efficacy or effectiveness was examined in 81% of reports, and costs were assessed in 65% of studies. These were the two most frequently examined aspects. Almost all assessments were descriptive literature reviews; 9% included meta-analyses and 32% had cost analyses or economic evaluations. Forty-four percent of reports had a clear description of the literature search strategy, and selection criteria were clearly specified in 38% of studies, but there was considerable variation among agencies in the level of description of these methods. Conclusions were clearly stated in 83% of the assessments' conclusions, and 13% had recommendations. When analyzed longitudinally, it is apparent that the quality of reports has improved markedly during the past decade. This was determined by examining the clarity of specifying the policy question(s) under investigation, the identification of the target audience of decision makers for the information, and by evaluating the thoroughness of the description of the methods used in the assessment.

CONCLUSIONS

Canadian government agencies have contributed a considerable quantity of health technology assessments. There has been very little duplication of technologies evaluated, and the quality of the assessment reports has markedly improved during the past decade.

A prospective evaluation of surgeon performed sonography as a screening test in blunt abdominal trauma

INTRODUCTION

Sonography has found a role in the evaluation of patients with abdominal injury. However, the accuracy of sonography as performed by non-radiologists remains controversial. This study aims to determine the accuracy of focused abdominal sonography for trauma when performed by surgeons.

MATERIALS AND METHOD

Over a 1-year period, 48 patients with abdominal injury were initially evaluated for free intraperitoneal fluid by sonography. These tests were performed by 2 surgeons who had received instructions and performed a minimum of 30 examinations. Sonographic findings were then compared with other diagnostic modalities including computed tomography (CT) scan, diagnostic peritoneal lavage and exploratory laparotomy.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for sonography were found to be 0.86, 0.92, 0.89, 0.90 and 0.89, respectively. Although not specifically sought for, 2 cases of solid organ injury and 1 haemothorax, which were missed in initial examinations and X-rays, were detected on sonography.

CONCLUSION

In conclusion, our initial experience suggests that local surgeons can perform a focused sonographic examination for trauma with acceptable accuracy. Although sonography lacks the sensitivity of diagnostic peritoneal lavage and the accuracy of CT scan, the diagnostic algorithm for abdominal trauma should include sonography as a screening test.

Edmonton Quality Assessment Tool for Drug Utilization Reviews: EQUATDUR-2: the development of a scale to assess the methodological quality of a drug utilization review

OBJECTIVE

The objective of this study was to develop an instrument that will assist in evaluating the methodological quality of drug utilization reviews (DURs) and studies of prescribing appropriateness.

DESIGN

An expert committee followed accepted steps for developing and testing new instruments. Consultations on content, face validity, and scoring of items were solicited from external experts. Seven raters tested an initial version; subsequently, a refined instrument was designed. The Edmonton Quality Assessment Tool for Drug Utilization Reviews (EQUATDUR-2) evaluates 3 domains: sample selection (1 item), data collection (1 item), and data analysis (3 items). Sixteen raters tested EQUATDUR-2 on a random sample of DURs.

MEASURES

The study measures were reliability-using random effects interclass correlation coefficients for ratings by individual raters (ICC2,1) and the mean of ratings (ICC2,k)-and variability between DUR quality levels and rater groups.

RESULTS

There were significant differences in methodological quality (P <0.001) and in mean scores comparing low-, moderate-, and high-quality DURs. Nonmethodologists' ratings exhibited significant variability (P = 0.03) and tended to be higher. Agreement varied for individual items (ICC2,1, 0.22 to 0.44; ICC2,k, 0.81 to 0.91) and for mean summary ratings (ICC2,1, 0.42 [95% CI, 0.28 to 0.61]; ICC2,k, 0.92 [95% CI, 0.86 to 0.96]). The average time to rate each DUR was 10.0 minutes (95% CI, 9.2 to 10.9).

CONCLUSIONS

EQUATDUR-2 is a succinct, self-administered instrument with evidence of validity and reliability. We recommend that > or =2 raters independently assess each DUR and resolve disagreements by consensus. EQUATDUR-2 will help clinicians and decision makers to evaluate the quality of DUR studies and provide a framework for enhancing rigor in the design, conduct, and reporting of DURs.

Introducing "evidence" into board decision-making

The purpose of this article is to report on the results of a workshop that introduced evidence-based decision-making techniques to Board members of regional health authorities in Alberta. results and conclusions: The workshop demonstrated that it is possible to design a process for the incorporation of evidence in administrative decision-making. The participants demonstrated that they were able to apply scientific evidence in administrative decision making and that the decisions taken were reasonably consistent. Also, in the absence of evidence, values took precedence in the decision-making process and the decisions taken were less consistent.

Potential role of NovoSeven in the prevention of rebleeding following aneurysmal subarachnoid haemorrhage

Rebleeding following aneurysmal subarachnoid haemorrhage is a major factor contributing to unfavourable outcome. Antifibrinolytic agents reduce the rate of rebleeding but increase the risk of cerebral ischaemia and infarction and hence provide no overall benefit. To address the theoretical concern that recombinant activated factor VII (NovoSeven, Novo Nordisk A/S, Bagsvaerd, Denmark) might increase the risk of cerebral ischaemia while stabilizing the clot at the site of aneurysmal rupture, an open-label, dose-escalation safety study has been developed in collaboration with the UK Spontaneous Intracranial Haemorrhage Group. The trial design includes the recruitment of 15 patients (aged 18 years or over) in good grade with subarachnoid haemorrhage verified by computerized tomography scan or lumbar puncture. Safety evaluation includes clinical observation, monitoring of laboratory variables, positron emission tomography (PET) scanning (rCBF, rOEF, rCMRO2) and transcranial Doppler ultrasound. To date, ten patients have been recruited [NovoSeven 80 microg/kg single bolus (n = 2), NovoSeven 80 microg/kg single bolus followed by continuous infusion at 3.5 microg/kg per h (n = 2) or 7 microg/kg per h (n = 1), or control (n = 5)]. Clinical observation, transcranial Doppler ultrasound and PET studies revealed no evidence of cerebral ischaemia in the first nine patients treated with NovoSeven. The last patient developed middle cerebral artery branch thrombosis contralateral to the aneurysm. The study is currently suspended pending further investigation.

Altered tissue electric properties in lung cancer patients as detected by bioelectric impedance vector analysis

Modifications of body composition are frequent in cancer patients. Bioelectric impedance analysis can specifically detect changes in tissue electric properties, which may be associated with outcome. We evaluated the distribution of the impedance vectors from 63 adult male patients with lung cancer, stages IIIB (33 patients) and IV (30 patients), in supportive therapy. Body weight change over the previous 6 m.o. was the same in both groups (stable/increased 36% and decreased in 62%). Patients were compared with 56 healthy subjects matched for gender, age, and body mass index (25 kg/m2). Impedance measurements (standard tetrapolar electrode placement on the hand and foot) were made with 50-kHz alternating currents. The resistance and reactance of the vector components were standardized by the height of the subjects and were plotted as resistance/reactance graphs. The impedance vector distribution was the same in patients with either stage IIIB or IV cancer. The mean vector position differed significantly between cancer patients and control subjects (Hotelling T2 test, P < 0.01) because of a reduced reactance component (i.e., a smaller phase angle) with preserved resistance component in both cancer groups. Patients with a phase angle smaller than 4.5 degrees had a significantly shorter, i.e., 18 m.o., survival. Body weight loss was not significantly associated with survival. In conclusion, impedance vectors from lung cancer patients were characterized by a reduced reactance component. The altered tissue electric properties were more predictive than weight loss of prognosis.

Will GnRH antagonists provide new hope for patients considered 'difficult responders' to GnRH agonist protocols?

We have assessed the use of cetrorelix, a gonadotrophin releasing hormone (GnRH) antagonist, in conjunction with clomiphene citrate and gonadotrophin in 31 in-vitro fertilization (IVF)/gamete intra-Fallopian transfer (GIFT) cycles for 25 difficult responders. Group I included 18 poor responders (24 cycles) with no live birth in 23 previous IVF cycles with GnRH agonists. Group II included seven patients (seven cycles) with polycystic ovaries. Thirteen previous IVF/GIFT cycles with GnRH agonists had resulted in one live birth and three of these patients had developed ovarian hyperstimulation syndrome (OHSS). The treatment protocol involved a daily dose of clomiphene citrate 100 mg for 5 days and gonadotrophin injections from cycle day 2. Cetrorelix 0.25 mg/day was started when the leading follicle reached 14 mm. The outcome in both groups was favourable compared to previous treatment with GnRH agonists. In group I the abandoned cycle rate was 29 versus 57% (P = 0.06). More oocytes were produced (6.4 versus 4.7 oocytes/cycle) at a lower dose of follicle-stimulating hormone (FSH) (709 versus 1163 IU/oocyte; P = 0.08) and two live births resulted (11.8%). In group II fewer oocytes were produced (10.2 versus 14.5 oocytes/cycle), using a lower dose of gonadotrophin (170 versus 189 IU/oocyte) and resulted in one ongoing pregnancy. No patients experienced OHSS. This report is preliminary and a further controlled randomized study is required.

Health economics in the Canadian pharmaceutical industry

OBJECTIVE

To assess the goals, strategic focus, structure, capabilities, activities and effectiveness of health economics (HE) departments in the Canadian pharmaceutical industry, to examine how these have evolved, and the implications of HE in the future of the pharmaceutical industry.

DESIGN AND INTERVENTIONS

A mixture of telephone and face-to-face interviews with members of the HE unit (survey 1) and the chief executive officers (CEOs) [survey 2] of the top 21 Canadian pharmaceutical companies was undertaken in 1997.

MAIN OUTCOME MEASURES AND RESULTS

17 out of 21 companies responded to the first survey, and 12 of the 17 CEOs responded to our second survey. The goals of the HE department in most of the pharmaceutical companies have evolved from supporting efforts to gain reimbursement on government drug plans to include pricing, promotion, internal decision-making and other activities. Members of the HE department perceive their work to be valuable to the company. The CEOs felt that the true value of HE data is not adequately understood by formulary reviewers and, therefore, HE data may be an impediment to market access.

CONCLUSIONS

The purpose of the HE department is to demonstrate the value of the company's product to provincial government insurers. However, pharmaceutical companies are having difficulty justifying the importance of the HE department because of inconsistencies in the interpretation of economic evaluations by healthcare payers.