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At least 217 records · Page 12Linked to original sources

PubMed1999

[Myocardial perfusion tomography imaging in patients without prior myocardial infarction--comparison between 201Tl, 99mTc-tetrofosmin and dual-isotope protocol (rest 201Tl/stress 99mTc-tetrofosmin)].

The authors compared retrospectively the diagnostic accuracy of three protocols--201Tl stress-redistribution, 2-day 99mTc-tetrofosmin and the dual-isotope protocol (rest 201Tl/stress99m Tc-tetrofosmin)--for the detection of ischaemic heart disease (IHD) in a total of 115 patients without previous myocardial infarction (IM). 201Tl protocol (group A) was used to examine 43 patients, incl. 15 women, mean age 51 years (38-69 years). The 2-day 99m Tc-tetrofosmin protocol was used to examine 39 patients incl. 12 women, mean age 49 years (30-71 years). The dual-isotope protocol was used in 33 patients, incl. 8 women, mean age 52 years (31-69 years). In all patients coronarography was performed, stenosis of the artery >50% was considered significant for IHD. The sensitivity of the dual-isotope protocol was 95% and 96% resp. and 92% in the 2-day tetrofosmin and 201Tl protocol, (p>0.05). The specificity of the dual-isotope protocol was 82% and 89% resp. and 88% in the 201Tl and 2-day tetrofosmin protocol, (p >0.05). The diagnostic accuracy was 91% in the dualisotope and 201Tl protocol and 92% in the 2-day protocol (p>0.05). No significant difference was revealed in the sensitivity, specificity and diagnostic accuracy for the detection of IHD between different protocols in patients without previous IM.

Adult↗

PubMed2005

Rapid scanning protocol for brain (18)F-FDG PET: a validation study.

UNLABELLED: Although (18)F-FDG PET is an established technique to assess brain glucose use, a shorter imaging time is preferable for patient convenience and increased throughput. The aim of this study was to validate a brain (18)F-FDG PET protocol more rapid than the conventional protocol. METHODS: For comparison of normalized metabolic activities, brain (18)F-FDG PET was performed on 60 healthy subjects and 25 patients with probable Alzheimer's disease (AD), and an additional 20 healthy subjects served as a control group to assess diagnostic performance between the conventional and rapid scanning protocols. Conventional scans were acquired for a total of 20 min (a 10-min emission and a 10-min transmission). Immediately after conventional scanning, rapid scanning was performed for a total of 4 min (a 3-min emission and a 1-min transmission). PET images were anatomically standardized using NEUROSTAT, with pixel values normalized to the individual global value. Two database sets, from the 2 protocols, were compared by regional values and pixel-by-pixel analysis. A receiver-operating-characteristic analysis was performed for comparison of diagnostic accuracy between the 2 protocols. A kinetic simulation study was also performed to examine the possible difference due to the time lag between the protocols. RESULTS: Although small differences in normalized activity were found in several regions in the healthy subjects between the 2 protocols, no significant difference was found in any region in the patient group. The coefficients of variation of the normalized activity were 20%-30% larger in the rapidly scanned images, but the mean z images and their coefficient-of-variation images did not differ. The kinetic simulation study suggested that the differences were caused by the time lag between the 2 protocols. No significant differences were found in area under the receiver-operating-characteristic curves, and the diagnostic accuracies for the detection of AD were virtually equal between the 2 protocols. CONCLUSION: The rapid scanning protocol used in the present study could provide results nearly equivalent to data from the conventional protocol. Thus, it is feasible to use this rapid protocol to detect AD, without losing diagnostic accuracy.

Aged↗

PubMed2006

Randomized trial for answers to clinical questions: evaluating a pre-appraised versus a MEDLINE search protocol.

OBJECTIVE: The paper compares the speed, validity, and applicability of two different protocols for searching the primary medical literature. DESIGN: A randomized trial involving medicine residents was performed. SETTING: An inpatient general medicine rotation was used. PARTICIPANTS: Thirty-two internal medicine residents were block randomized into four groups of eight. MAIN OUTCOME MEASURES: Success rate of each search protocol was measured by perceived search time, number of questions answered, and proportion of articles that were applicable and valid. RESULTS: Residents randomized to the MEDLINE-first (protocol A) group searched 120 questions, and residents randomized to the MEDLINE-last (protocol B) searched 133 questions. In protocol A, 104 answers (86.7%) and, in protocol B, 117 answers (88%) were found to clinical questions. In protocol A, residents reported that 26 (25.2%) of the answers were obtained quickly or rated as "fast" (<5 minutes) as opposed to 55 (51.9%) in protocol B, (P = 0.0004). A subset of questions and articles (n = 79) were reviewed by faculty who found that both protocols identified similar numbers of answer articles that addressed the questions and were felt to be valid using critical appraisal criteria. CONCLUSION: For resident-generated clinical questions, both protocols produced a similarly high percentage of applicable and valid articles. The MEDLINE-last search protocol was perceived to be faster. However, in the MEDLINE-last protocol, a significant portion of questions (23%) still required searching MEDLINE to find an answer.

Computer User Training↗

PubMed2002

Effect of mechanical ventilator weaning protocols on respiratory outcomes in infants and children: a randomized controlled trial.

CONTEXT: Ventilator management protocols shorten the time required to wean adult patients from mechanical ventilation. The efficacy of such weaning protocols among children has not been studied. OBJECTIVE: To evaluate whether weaning protocols are superior to standard care (no defined protocol) for infants and children with acute illnesses requiring mechanical ventilator support and whether a volume support weaning protocol using continuous automated adjustment of pressure support by the ventilator (ie, VSV) is superior to manual adjustment of pressure support by clinicians (ie, PSV). DESIGN AND SETTING: Randomized controlled trial conducted in the pediatric intensive care units of 10 children's hospitals across North America from November 1999 through April 2001. PATIENTS: One hundred eighty-two spontaneously breathing children (<18 years old) who had been receiving ventilator support for more than 24 hours and who failed a test for extubation readiness on minimal pressure support. INTERVENTIONS: Patients were randomized to a PSV protocol (n = 62), VSV protocol (n = 60), or no protocol (n = 60). MAIN OUTCOME MEASURES: Duration of weaning time (from randomization to successful extubation); extubation failure (any invasive or noninvasive ventilator support within 48 hours of extubation). RESULTS: Extubation failure rates were not significantly different for PSV (15%), VSV (24%), and no protocol (17%) (P =.44). Among weaning successes, median duration of weaning was not significantly different for PSV (1.6 days), VSV (1.8 days), and no protocol (2.0 days) (P =.75). Male children more frequently failed extubation (odds ratio, 7.86; 95% confidence interval, 2.36-26.2; P<.001). Increased sedative use in the first 24 hours of weaning predicted extubation failure (P =.04) and, among extubation successes, duration of weaning (P<.001). CONCLUSIONS: In contrast with adult patients, the majority of children are weaned from mechanical ventilator support in 2 days or less. Weaning protocols did not significantly shorten this brief duration of weaning.

Adolescent↗

PubMed2007

Achieving durable glucose control in the intensive care unit without hypoglycaemia: a new practical IV insulin protocol.

BACKGROUND: Hyperglycaemia occurs in a substantial portion of critically ill patients in our intensive care units. Near normalization of elevated blood glucose levels with IV insulin may improve outcome. However, currently published IV insulin protocol are not ideal; most are relatively complex and often result in hypoglycaemia. We designed a protocol that would be practical to use while incorporating the necessary complexities required to achieve good glucose control, coupled with a low incidence hypoglycaemia. METHODS: The essential part of the protocol is a matrix specifying the amount by which an insulin flow rate is to be changed. The intersection of the current and the previous blood glucose values on the matrix locates the appropriate cell containing the required change in insulin flow rate. No additional calculations or tables are required. RESULTS: The initial glucose level obtained by blood glucose meter (BGM) averaged 253.5 +/- 95.6 mg/dL and fell below 140 within 9.3 h on the protocol. The average BGM on the protocol was 133.5 +/- 43.9 mg/dL. Only 0.09% of all glucose values were <40 mg/dL and insulin had to be held only 2.2% of the time on the protocol. Physician input was not required and nursing accuracy in applying the protocol was greater than 94%. This protocol has been adopted as the default IV insulin protocol for the NorthShore-LIJ Health System and several other medical centers. CONCLUSION: A practical IV insulin protocol that has been extensively tested is presented. The protocol has been implemented at multiple institutions indicating its ease of use and excellent results.

Aged↗

PubMed1993

Towards a protocol for measurement of maximum spatial peak temporal average acoustic intensity from diagnostic B mode ultrasound scanners in the field.

The Northern Regional Medical Physics Department has been involved in measurement of the acoustic output of diagnostic ultrasound equipment for several years. As the complexity of diagnostic ultrasound equipment has increased, so have the problems of measuring the acoustic outputs of this equipment in the field. Measurements made in the field are often made on unfamiliar pieces of equipment and under tight constraints of time. In these circumstances the magnitude and the conditions under which the true maximum Ispta value occurs may not always be found. The aim of a measurement protocol is therefore to facilitate the measurement of Ispta in the field, so that the measured maximum Ispta value is as close as possible to the 'true maximum' Ispta value. To be of practical benefit the protocol must be succinct and easy to use, as well as applicable to most if not all types of scanner. Our experience has led us to believe that this is possible and that the benefits of a well designed measurement protocol will far outweigh any disadvantages. The development of two measurement protocols is discussed in this paper. The time required to carry out each measurement depends on the number of assumptions made about the operation of the scanner in the protocol used. The first protocol makes very few assumptions about the operation of a scanner; the results from measurements made using this protocol can be used to assess the validity of the much larger number of assumptions made in the second protocol. The results from measurements on three types of scanner using the two protocols are presented. The results demonstrate the validity of most of the assumptions made by the protocols and the potential benefits of using a protocol for measurement of maximum Ispta in the field in terms of reduced measurement time and greater consistency.

Acoustics↗

PubMed1997

Is ownership more important than the scientific credibility of audit protocols? A survey of medical audit advisory groups.

BACKGROUND: It is commonly accepted that ownership is an important factor in determining the acceptability and use of protocols or guidelines. OBJECTIVES: We aimed to determine whether Medical Audit Advisory Groups (MAAGs) are prepared to accept and use audit protocols developed systematically by an external agency. METHOD: A postal questionnaire was sent to all 105 MAAG chairmen in England and Wales to seek their views on the external development of protocols, the inclusion of evidence-based prioritized criteria, the general design of the protocols issued by the Lilly Audit Centre and the numbers of practices reported by MAAGs as making use of at least one of the first four protocols issued. RESULTS: Ninety-five MAAGs (90%) responded. Of these, 86% were in favour of the external development of protocols, and 98% and 94%, respectively, found evidence-based and prioritized criteria valuable; 98% felt the overall design and content of the Audit Centre protocols were excellent or good. A total of 1018 practices was known to have made use of one of these protocols, 261 taking part in multi-practice audits organized by their MAAGs. CONCLUSION: Ownership is not necessarily more important than scientific credibility and/or perceived utility. Externally developed audit protocols containing evidence-based, prioritized review criteria are acceptable to MAAGs, which are prepared to recommend their use in practice. Accordingly, such systematically developed protocols offer a promising and practical method for improving clinical effectiveness. Further research is needed, however, to determine the comparative impact on standards of care of protocols and other methods such as clinical guidelines.

Attitude of Health Personnel↗

PubMed2006

Evaluation of an intensive insulin protocol for septic patients in a medical intensive care unit.

OBJECTIVE: Intensive insulin therapy to normalize blood glucose may improve outcome in intensive care unit patients. We prospectively evaluated the implementation of an intensive insulin protocol in medical intensive care patients to identify and overcome obstacles that this complex therapy creates. DESIGN: This prospective, quality assessment study was designed to establish a standard protocol for glucose control in critically ill patients. SETTING: The study took place in the medical intensive care unit at the Medical University of South Carolina, a tertiary care center. PATIENTS: Patients diagnosed with sepsis and two consecutive blood glucose measurements of >120 mg/dL were included in the study. INTERVENTIONS: The protocol, targeting blood glucose of 80-120 mg/dL, was a multidisciplinary initiative involving extensive education of house staff before subject enrollment. Based on predefined criteria, patients were monitored daily for glycemic control, inclusion criteria, and protocol adherence. Protocol improvements were assessed at 6 and 12 months via nursing surveys. MEASUREMENTS AND MAIN RESULTS: Seventy patients receiving insulin infusion for >8 hrs were included in data analysis, accounting for 4,920 glucose readings. Eighty-six hypoglycemic events were recorded, with the number of events decreasing from 7.6% to 0.3% by the final version of the protocol. Average duration on protocol was 6 days, and average time to target range was 5.4 hrs. Identifiable causes of hypoglycemia and survey results led to four protocol revisions by study completion. CONCLUSIONS: In comparison to studies suggesting that normoglycemia is an easily achievable goal, our protocol often recorded glucose values <80 mg/dL, although values <60 mg/dL were rare and usually due to protocol violations. In the interval before automated glucose-sensing insulin infusion devices become available for the intensive care unit, the current protocol is available to assist others in achieving target glucose levels shown to improve mortality rate in an intensive care unit population.

Academic Medical Centers↗

PubMed2003

The PropeR way to support medical doctors in daily practice. Developing the protocol based DSS.

This paper describes the first phase of the development of a Protocol based Decision Support System (PDSS) that will be linked to an Electronic Patient Record system (EPR system). The protocol system will be pro-active: the physician will be automatically prompted from the EPR of a particular patient if the protocol that applies for that patient defines it necessary. The PropeR project studies the impact of a PDSS that is linked to an EPR on daily care processes. There are two areas of research: hospital and home care. This paper describes the application in the hospital. The protocol that is being computerized is a treatment protocol for Acute Myelogenous Leukaemia (AML) that also studies treatment alternatives (conventional versus experimental treatment). This paper based AML protocol has been translated into a formal representation. The KA-tool Gaston is used to make this representation. Twenty-eight subprotocols have been organized in a hierarchical structure with three levels. One of the aims of the project is to make a representation of the AML protocol that can be used in other organizations as well. The main problem we encountered is that the representation not only contains the content of the protocol, but also aspects of application of that protocol in daily care of the hospital and aspects of support. The solution to this problem is the creation of two layers of representation: the first layer is an exact copy of the protocol and thus sharable and the second layer focuses on the support of the protocol in the daily working processes and is mainly domain specific: for the University Hospital Maastricht. At the moment, this division into two layers is being discussed.

Acute Disease↗

PubMed1994

A comparison of the British Hypertension Society and Association for the Advancement of Medical Instrumentation protocols for validating blood pressure measuring devices: can the two be reconciled?

BACKGROUND: Experience with the original protocols of the Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS) for validating blood pressure has provided valuable insight into the methodological problems associated with device validation and has influenced both the BHS and the AAMI in revising their protocols. OBJECTIVES: To review the revisions of the original BHS and AAMI protocols; to compare the protocols; and, using the BHS protocol as a framework for validation, to determine how it should be modified to a protocol that will fulfil the criteria of both the AAMI and the BHS. CONCLUSIONS: The revised protocols have many similarities but there are some important differences. These differences merit consideration so as to facilitate manufacturers seeking to validate devices for acceptance in both Europe and the United States. Of the two protocols, the BHS protocol is the more elaborate in that (1) it takes particular care to ensure that observers are trained to a very high standard, (2) it makes provision for special group validation and (3) it recommends in-use validation of all devices. By modifying the BHS protocol, it is possible to validate blood pressure measuring devices (ambulatory devices require special consideration) to satisfy the criteria of both protocols.

Blood Pressure Determination↗

PubMedDate not supplied

Comparison of three protocols for breathing exercises during immersion in 38 degrees C water for chronic obstructive pulmonary disease.

Respiratory function test, arterial blood gas analysis, and ejection fraction were used to compare three protocols of breathing exercises during immersion in 38 degrees C water. Therapy was given for 2 mo to patients with stable chronic obstructive pulmonary disease. Protocol A consisted of a total exercise period of 20 min/wk (10 min/day, 2 days/wk) and was performed by 7 patients (5 cases of asthma and 2 cases of emphysema). Protocol B consisted of a total exercise period of 120 min/wk (20 min x 2 per day at 10:00 am and 3:00 pm, 3 days/wk) and was performed by 9 patients (6 asthmas and 3 emphysemas). Protocol C consisted of a total exercise period of 120 min/wk (20 min/day, 6 days/wk) and was performed by 8 patients (4 asthmas and 4 emphysemas). The ratio of forced expired volume in one second to forced vital capacity (FEV1.0%) was significantly increased in protocols B and C (P < 0.01). The ratio of forced vital capacity to the predicted normal value (%FVC) was not changed in any of the three protocols. A significant increase in peak flow was observed in protocols B and C (P < 0.05). The maximal expiratory flow at 25% (V25) was not changed in any of the three protocols. PaO2 was significantly increased and PacO2 was significantly decreased in protocol B (P < 0.01 and P < 0.05, respectively), whereas only PaCO2 was significantly decreased in protocol C (P < 0.05). Ejection fraction was increased in protocols B and C. These results suggest that exercise for a total period of 120 min/wk is preferable to that of 20 min/wk in COPD.

Aged↗

PubMed1995

Four- versus 6-minute infusion protocol for adenosine thallium-201 single photon emission computed tomography imaging.

Intravenous adenosine infusion results in immediate maximal coronary arteriolar vasodilatation. Side effects occur in most patients who receive adenosine. For these reasons, a shorter infusion for pharmacologic stress thallium-201 testing may improve patient tolerability without compromising diagnostic accuracy. In a retrospective, unblinded evaluation, we compared side effects and accuracy of a standard 6-minute adenosine infusion single photon emission computed tomography (SPECT) study with a 4-minute protocol in 730 and 621 patients, respectively. Adenosine was infused at 140 micrograms/kg/minute in both groups; thallium-201 was injected at the 3-minute mark of the 4-minute protocol and at the 4-minute mark of the 6-minute protocol. Angiographic follow-up (mean 8 days) after thallium-201 testing was available in 233 (32%) of the patients in the 6-minute protocol and in 174 (28%) of the patients in the 4-minute protocol (p not significant (NS). Side effects occurred in 90% of the patients in the 6-minute protocol and in 91% of the patients in the 4-minute protocol (p = NS). Premature termination of the infusion was required in 4% of the patients in the 6-minute protocol and 2% of the patients in the 4-minute protocol (p = 0.02). Second- or third-degree atrioventricular block was noted in 4.5% and 3.0% of the 6- and 4-minute groups, respectively (p = NS). The duration of symptoms averaged 2.9 +/- 4.4 minutes in the patients in the 6-min protocol and 2.1 +/- 1.6 minutes in the patients in the 4-minute protocol (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

PubMed1991

Glucocorticoid type II receptors of the spinal cord show lower affinity than hippocampal type II receptors: binding parameters obtained with different experimental protocols.

We have used three experimental protocols to determine binding parameters for type I and type II glucocorticoid receptors in the spinal cord and hippocampus (HIPPO) from adrenalectomized rats. In protocol A, 0.5-20 nM [3H]dexamethasone (DEX) was incubated plus or minus a 1000-fold excess of unlabeled DEX, assuming binding to a two-site model. In protocol B, [3H]DEX competed with a single concentration of RU 28362 (500 nM), whereas in protocol C, we used a concentration of RU 28362 which varied in parallel to that of [3H]DEX, such as 500 x. Results of protocols A and C were qualitatively similar, in that: (1) Bmax for type I receptors favored the HIPPO, while the content of type II sites was comparable in the two tissues; (2) Kd was consistently lower for type I than for type II sites in both tissues; and (3) type II receptors from the spinal cord showed lower affinity than their homologous sites from HIPPO. This last result was also obtained when using protocol B. In contrast, protocol B yielded binding data indicating that type II sites were of similar or higher affinity than type I sites. Computer simulation of the binding protocols demonstrated that protocols A and C were the most theoretically reliable for estimating the Kd and Bmax of type I sites, and the predicted error was smaller for protocol C, in comparison with protocol B. We suggest that the noted differences in the Kd of type II receptors between the spinal cord and HIPPO could account for a difference in sensitivity of the two systems in the physiological adrenal hormone range.

Animals↗

PubMed2005

Performance of methicillin-resistant Staphylococcus aureus protocols in Dutch hospitals.

BACKGROUND: Although numerous studies have stressed the importance of compliance with methicillin-resistant Staphylococcus aureus (MRSA) protocols with regard to cost reduction and a safer environment for health care workers and patients, an evaluation of the usability of the protocols themselves is lacking. In this study, we evaluated the usability and performance of those protocols. METHODS: The performance of MRSA protocols was examined in 5 Dutch hospitals by means of a questionnaire (n = 63), followed by a practical test (n = 50), in a stratified random sample of 3 types of health care workers (physicians, nursing staff, and cleaning personnel). The questionnaire consisted of constructs related to exposure to risk, risk perception, knowledge of and attitude toward the protocols and safety preventive measures, self-reported behavior, and social and organizational support. The practical test consisted of "what if" scenarios that simulate the actual use of the protocol as a guideline for solving infection problems. The health care workers were asked to verbalize their thoughts and actions while using the protocol. RESULTS: The questionnaire demonstrated adequate knowledge of and attitude toward the MRSA protocols. However, the practical test revealed that the majority of respondents had problems with the accessibility, comprehensibility, applicability, and acceptability of the protocols. Problems not only occurred because of unclear information about the preventive measures and a poor infrastructure but also because of preventive measures that conflict with principles in providing care. CONCLUSION: The protocols do not reflect the practical needs of the health care workers. In view of the different decisions that health care workers have to take in various circumstances, it would be impracticable to use the same MRSA protocol for all hospital staff. Finally, the practical test provided more reliable results than the questionnaire.

Adult↗

PubMed2003

Prospective evaluation of two stimulation protocols for low responders who were undergoing in vitro fertilization-embryo transfer.

OBJECTIVE: To compare two stimulation protocols designed for low responders undergoing IVF. DESIGN: Randomized, prospective study. SETTING: University hospital IVF unit. PATIENT(S): Sixty low responders who were recruited on the basis of results in previous cycles. INTERVENTION(S): Modified flare protocol in which a high dose of GnRH agonist was administered for the first 4 days, followed by a standard agonist dose, or a modified long protocol in which a standard agonist dose was used until pituitary down-regulation, after which the agonist dose was halved during stimulation. MAIN OUTCOME MEASURE(S): Number of oocytes retrieved. RESULT(S): Twenty-nine cycles were performed with the modified flare protocol and 31 were performed with the modified long protocol. Significantly more oocytes were obtained with the modified long protocol than the modified flare protocol (4.42 +/- 2.6 vs. 3.07 +/- 2.15). The number and quality of embryos available for transfer was similar in both groups. One clinical pregnancy (3.4%) was achieved with the modified flare protocol, and 7 pregnancies (22.5%) were achieved using the modified long protocol. CONCLUSION(S): These preliminary results substantiate the poor prognosis and outcome for low responders undergoing IVF. A modified long "mini-dose" protocol appears to be superior to a modified mega-dose flare protocol in terms of oocyte yield and cycle outcome.

Adult↗

PubMed1998

A brain tumor dose escalation protocol based on effective dose equivalence to prior experience.

PURPOSE: The current study describes the design of a dose escalation protocol for conformal irradiation of primary brain tumors that preserves the safe experience of a previous, sequential dose escalation scheme while enabling the delivery of substantially higher effective doses to a central target volume. METHODS AND MATERIALS: Normalized isoeffective composite dose distributions were formed for 20 patients treated on the original protocol (which specified three progressively smaller planning target volumes [PTVs]) using the linear quadratic model (here corrected to equivalent 2 Gy fractions using alpha/beta=10 Gy). These distributions were investigated and a new protocol was designed to preserve a similar level of efficacy and lack of toxicity for the outer volumes, but allowing a higher dose to the inner PTV. Treatment plans were then investigated to determine if the objectives of the new protocol were achievable. In particular, plans that simultaneously achieved all biological treatment planning objectives (all fields treated each day) were investigated. Finally, the success of the protocol design was demonstrated by analysis of the effective dose distributions of 10 patients treated using the new protocol. RESULTS: The composite normalized isoeffective minimum doses to the outer PTVs (PTV3 and PTV2) in the original protocol were close to 60 Gy and 75 Gy, respectively, and these values are specified as the minimum doses to those volumes for the new protocol. Homogeneity requirements to maintain equivalence for the outer target volume domains are: not more than 25% of [PTV3 exclusive of PTV2] >75 Gy; and not more than 50% of [PTV2 exclusive of PTV1] >85 Gy. Treatment plans using multiple noncoplanar arrangements of beams and static intensity modulation treat all volumes at each session. DVHs of the normalized isoeffective dose distributions reveal the equivalence of the new protocol plans to the sequential plans in the previous protocol as well as the ability to achieve a higher dose of 90 Gy to the isocenter of PTV1 (+/-5% homogeneity required). CONCLUSION: The ability to incorporate past experience through use of the linear quadratic model in the design of a new dose escalation protocol is demonstrated.

Brain Neoplasms↗

PubMed1991

Comparison of logdose and bracket protocols for determination of epinephrine arrhythmia thresholds in dogs anesthetized with thiopental-halothane.

Previous studies in dogs of anesthetic-epinephrine arrhythmias have used logdose or bracketed epinephrine infusion protocols to determine the arrhythmic dose of epinephrine (ADE) or plasma level of epinephrine at arrhythmias (PCE). Reported logdose ADE values for halothane preceded by thiopental induction (thiopental-halothane) are twice those with the bracket protocol. There are no reported PCE data for the bracket protocol, and neither protocol has been directly compared in the same dogs. Therefore, direct comparisons were made of thiopental-halothane ADE and PCE in seven dogs (group 1). Dogs were induced with thiopental (20 mg/kg), followed by halothane inhalation at end-tidal concentrations equivalent to MAC 1.25. Epinephrine infusion protocols were compared on two weekly test occasions, with the sequence and order of protocol testing randomized. Logdose ADE for four or more ventricular beats within 15 s was 3.92 +/- 0.60 micrograms/kg (mean +/- standard error), higher than the bracket ADE (2.54 +/- 0.34 micrograms/ml) (P less than 0.05). PCE at ADE were similar for both protocols, but six separate infusions of epinephrine were required to establish ADE with the logdose compared to four with the bracket protocol (P less than 0.05). These findings suggested enhanced epinephrine clearance with the logdose protocol. Therefore, five additional but similarly anesthetized dogs (group 2) were tested to determine if physiologic or hemodynamic conditions prior to epinephrine infusions ("initial conditions") were equivalent for both protocols. Protocols were modified to avoid provocation of ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2006

Impact of a lung transplantation donor-management protocol on lung donation and recipient outcomes.

RATIONALE: One of the limitations associated with lung transplantation is the lack of available organs. OBJECTIVE: To determine whether a lung donor-management protocol could increase the number of lungs for transplantation without affecting the survival rates of the recipients. METHODS: We implemented the San Antonio Lung Transplant protocol for managing potential lung donors according to modifications of standard criteria for donor selection and strategies for donor management. We then compared information gathered during a 4-yr period, during which the protocol was used with information gathered during a 4-yr period before protocol implementation. Primary outcome measures were the procurement rate of lungs and the 30-d and 1-yr survival rates of recipients. MAIN RESULTS: We reviewed data from 711 potential lung donors. The mean rate of lung procurement was significantly higher (p < 0.0001) during the protocol period (25.5%) than during the pre-protocol period (11.5%), with an estimated risk ratio of 2.2 in favor of the protocol period. More patients received transplants during the protocol period (n = 121) than during the pre-protocol period (n = 53; p < 0.0001). Of 98 actual lung donors during the protocol period, 53 (54%) had initially been considered poor donors; these donors provided 64 (53%) of the 121 lung transplants. The type of donor was not associated with significant differences in recipients' 30-d and 1-yr survival rates or any clinical measures of adequate graft function. CONCLUSIONS: The protocol was associated with a significant increase in the number of lung donors and transplant procedures without compromising pulmonary function, length of stay, or survival of the recipients.

Adult↗