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2.
J Surg Educ ; 69(1): 118-25, 2012.
Article in English | MEDLINE | ID: mdl-22208843

ABSTRACT

PURPOSE: In 1985, a small research group identified variables affecting applicant success on the oral Certifying Examination (CE) of the American Board of Surgery (ABS). This led to the design of an oral examination course first taught in 1991. The success of and need for this program led to its continuation. The results from the first 10 years were presented at the 2001 Association of Program Directors in Surgery annual meeting.(1) We now report the outcomes for the course of the second 10 years as measured by success on the CE. METHODS: Thirty-six courses were held over 20 years. There were 57 invited faculty from 27 general surgery programs throughout the United States and Canada. The participant-to-faculty ratio ranged from 16:7 to 5:1 in the newer 3-day format (2007). Courses were offered at sites that replicated the actual examination setting. Each course included (1) pretest and posttest examinations, (2) analysis of case presentation skills, (3) measurement of communication apprehension, (4) 1:1 faculty feedback, (5) small-group practice sessions, (6) individual videotaping, (7) didactic review of specific behaviors on examinations, (8) a debrief session with two faculty members, and (9) a written evaluative summary that included an improvement strategy. RESULTS: There were 36 courses with 326 participants (30-54 years). Follow-up data are available for 225 participants. Trends were analyzed between 1991-2001 and 2002-2011. As resident performance on the CE increased in importance, applicant profiles changed from those who had previously failed (1991-2001) to residents identified by program directors as needing assistance (52%). Since 2002, most course participants (69%) who had failed the CE had completed at least 1 other review course. Participants reported more significant stressors (2002-2011) 9%, but communication apprehension remained the same. As a result, individual counseling for anger and family stressors was integrated into the course. The perception of knowledge deficits was associated with those who enrolled in fellowship training and delayed their examination. The recent groups exhibited more professionalism and articulation issues related to performance. Five surgeons (2002-2011) were asked not to return to the course because of severe knowledge deficiencies or ethical/behavioral issues based on faculty evaluations. Although complete follow-up of all participants was not possible (only 225/326), the success rate among those providing follow-up was 97% for those who followed their remediation plan, giving 218/326, a worse-case pass rate of 67%. CONCLUSION: Communication and professionalism deficits are still common in those struggling with the CE, Early identification of those at risk of failing by program directors who are documenting the competencies may promote earlier interventions and thus lead to success. This program continues to be effective at identifying behaviors that interfere with success on the CE of the ABS.


Subject(s)
Certification , Clinical Competence , Communication , General Surgery/standards , Specialty Boards , Adult , Female , Humans , Male , Middle Aged , Surveys and Questionnaires , Time Factors , United States
4.
Anesth Analg ; 110(3): 685-93, 2010 Mar 01.
Article in English | MEDLINE | ID: mdl-20042443

ABSTRACT

BACKGROUND: In consenting Jehovah's Witness patients and others for whom blood is contraindicated or not available, hemoglobin-based oxygen carrier (HBOC)-201 may enable survival in acutely anemic patients while underlying conditions are treated. METHODS: Survival factors were identified in a multicenter, unblinded series of severely anemic "compassionate use" patients receiving available standard treatment plus consultant-supported HBOC-201 administration by novice users. Predictors of outcome were sought and compared between survivors and nonsurvivors. A compound variable, hemoglobin-duration deficit product was used to describe the interactive clinical effects of severity and duration of anemia. Mortality,correlations between patient characteristics, and survival to hospital discharge were determined from patient records. RESULTS: Fifty-four patients (median age 50 years) with life-threatening anemia (median hemoglobin concentration at time of request = 4 g/dL) received 60 to 300 g HBOC-201.Twenty-three patients (41.8%) were discharged. Intraoperative blood loss (45%), malignancy(18%), and acute hemolysis (13%) were the prevailing reasons for anemia. Time from onset of anemia (< or = 8 g/dL) to HBOC-201 infusion was shorter for survivors than nonsurvivors (3.2 vs 4.4 days, P = 0.027). Mean hemoglobin levels before HBOC-201 infusion in survivors and nonsurvivors were 4.5 and 3.8 g/dL, respectively (P = 0.120). No serious adverse event was attributed to HBOC-201. The hemoglobin-duration deficit product separated survivors from nonsurvivors. Cancer and renal disease were associated with nonsurvival. CONCLUSION: Earlier, compared with later, administration by inexperienced users of HBOC-201 to patients with anemia was associated with improved chances of survival of acutely bleeding and hemolyzing patients. Survival was more likely if the duration and magnitude of low hemoglobin was minimized before treatment with HBOC-201.


Subject(s)
Anemia/therapy , Blood Substitutes/therapeutic use , Blood Transfusion , Hemoglobins/therapeutic use , Jehovah's Witnesses , Religion and Medicine , Treatment Refusal , Aged , Anemia/blood , Anemia/mortality , Blood Substitutes/adverse effects , Compassionate Use Trials , Contraindications , Female , Hemoglobins/adverse effects , Humans , Male , Middle Aged , Risk Assessment , Risk Factors , Severity of Illness Index , Survival Analysis , Time Factors , Treatment Outcome , United States
5.
Article in English | MEDLINE | ID: mdl-20047515

ABSTRACT

In addition to heme-irons, reactive (beta-globin thiols (betaCys93s) of hemoglobin (Hb) also have been shown to interact with endogenous nitric oxide (NO) thereby contributing to vascular tone regulation. What relative roles do these NO binding sites contribute to the overall Hb-mediated vasoactivity? Several test Hbs with either or both the NO binding sites preliganded or blocked were prepared and tested in a rat thoracic aortic ring model. Hbs tested were: NEM-Hb (ferrous Hb with masked thiols), HbNO (ferrous Hb preliganded with NO), Hb(+)CN (ferric Hb liganded with CN(-)), NEM-HbNO and NEM-Hb(+)CN (Hbs with both heme-iron and cysteine sites preliganded or blocked). Typically, >0.2 microM control Hb significantly increased isometric tension in agonist stimulated vessel rings (58.1 +/-7.0% over baseline). At comparable concentrations, NEM-Hb also caused a significant contraction (50.7+/-9.5%) while HbNO and Hb(+)CN did not (-5.5+/-6.0% and -3.7+/-4.6%, respectively). For these Hbs, masking thiols as well did not significantly alter respective vascular effects. Ferrous sperm whale myoglobin (Mb), which has no reactive thiol, elicited a significant contraction (55.1+/-13.2%) while metMb did not (-0.8+/-3.2%), suggesting the relative importance of heme-iron ligand and oxidation state in Hb vasoactivity. Additionally, ferrous or ferric equine heart cytochrome-C, a heme protein with no readily available heme-iron and cysteine binding sites, did not elicit notable contraction. Human Hb variants in which (betaCys93s are deleted or substituted with non-cysteine residues did not reveal any documented significant hemodynamic abnormalities. These results indicate that reactive globin-thiols do not appear to play a prominent role relative to heme-irons in Hb-mediated vasoconstriction.


Subject(s)
Aorta, Thoracic/physiology , Heme/metabolism , Hemoglobins/metabolism , Iron/metabolism , Vasoconstriction , Animals , Binding Sites/genetics , Binding Sites/physiology , Cells, Cultured , Cysteine/genetics , Heme/analogs & derivatives , Hemoglobins/chemistry , Humans , Iron/chemistry , Male , Mutation/genetics , Nitric Oxide/metabolism , Organ Culture Techniques , Rats , Rats, Sprague-Dawley , Sulfhydryl Compounds/chemistry
7.
Crit Care Clin ; 25(2): 415-24, Table of Contents, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19341917

ABSTRACT

There is an ongoing need for a red cell substitute, an oxygen-carrying solution to use primarily as a bridge until red cells are available. The replacement of oxygen-carrying capacity has driven the field of research, primarily with the development of hemoglobin-based oxygen carriers, but they are less than ideal. The formulation of a complete substitute for blood, if it can be realized, must take into account all the cellular and molecular components of the immune and coagulation systems.


Subject(s)
Blood Substitutes , Blood Transfusion/methods , Drug Design , Drug Evaluation , Humans , Oxygen/blood , Oxyhemoglobins/chemistry , Oxyhemoglobins/metabolism , Technology, Pharmaceutical/methods
8.
EuroIntervention ; 4(1): 161-5, 2008 May.
Article in English | MEDLINE | ID: mdl-19112795

ABSTRACT

Clinical and preclinical studies have revealed a diverse array of indications in which the effectiveness of HBOC-201 has been demonstrated or appears likely. Included among these are indications involving cardiac and peripheral ischaemia in which this oxygen therapeutic may prove to be an important tool in the armamentarium of the cardiologist and surgeon. Preclinical studies and clinical trials are under way to further delineate and optimise the role of HBOC-201 as an oxygen therapeutic in cardiovascular medicine.


Subject(s)
Anemia/therapy , Blood Loss, Surgical , Blood Substitutes/therapeutic use , Hemoglobins/therapeutic use , Animals , Humans , Randomized Controlled Trials as Topic
9.
J Trauma ; 64(6): 1484-97, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18545113

ABSTRACT

BACKGROUND: The ability of hemoglobin based oxygen carrier-201 (HBOC-201) to safely reduce and/or eliminate perioperative transfusion was studied in orthopedic surgery patients. METHODS: A randomized, single-blind, packed red blood cell (PRBC)-controlled, parallel-group multicenter study was conducted. Six hundred eighty-eight patients were randomized to treatment with HBOC-201 (H, n = 350) or PRBC (R, n = 338) at the first transfusion decision. Primary endpoints were transfusion avoidance and blinded assessment [Mann-Whitney estimator (MW)] of safety noninferiority. Groups were compared directly and by paired/matching group analyses predicated on a prospectively defined dichotomy [treatment success (HH) vs. failure (HR)] in the H arm and an equivalently defined dichotomy [3 (R3+) units PRBC] in the R arm, based on need (moderate vs. high) for additional oxygen carrying capacity. RESULTS: A total of 59.4% of patients in the H arm avoided PRBC transfusion. Adverse events (8.47 vs. 5.88), and serious adverse events (SAEs) (0.35 vs. 0.25) per patient were higher in the H versus R arms (p < 0.001 and p < 0.01) with MW = 0.561 (95 CI 0.528-0.594). HH versus R3- had identical (0.14) serious adverse events/patient and a MW = 0.519 (95% confidence limit 0.481-0.558), whereas the incidence was higher (0.63 vs. 0.47) for HR versus R3+ with a MW = 0.605 (95% confidence limit 0.550-0.662). Age (>80 years), volume overload and undertreatment contributed to this imbalance. CONCLUSION: HBOC-201 eliminated transfusion in the majority of subjects. The between arms (H vs. R) safety analysis was unfavorable and likely related to patient age, volume overload, and undertreatment and was isolated to patients that could not be managed by HBOC-201 alone. However, patients <80 years old with moderate clinical need may safely avoid transfusion when treated with up to 10 units of HBOC-201.


Subject(s)
Blood Loss, Surgical/prevention & control , Elective Surgical Procedures , Erythrocyte Transfusion , Hemoglobins/administration & dosage , Orthopedic Procedures/methods , Adult , Blood Substitutes/administration & dosage , Evaluation Studies as Topic , Female , Follow-Up Studies , Humans , Male , Middle Aged , Probability , Risk Assessment , Safety , Single-Blind Method , Statistics, Nonparametric , Treatment Outcome
10.
Article in English | MEDLINE | ID: mdl-17090427

ABSTRACT

In this brief overview, recent progress and current status of blood substitute research and development is summarized. Current blood substitute development efforts are focused on red blood cell substitutes but substitutes for platelets and other blood components are also in progress. Red cell substitutes currently in various stages of development are semi-synthetic or synthetic oxygen carriers that include "stealth" or "masked" red cells, hemoglobin-based oxygen carriers and perfluorocarbon-based oxygen carriers. Artificial platelets (or platelet substitutes) are in early stages of development and include human platelet fragments or particles of synthetic/semi-synthetic materials or recombinant human serum albumin coupled with platelet surface receptor fragments. Of note, some recombinant clotting factors (Factors VII, VIII, IX) have already been successfully developed and licensed for treatment of hemophilia. In addition, some future approaches and prospects of blood component replacement therapeutics are discussed.


Subject(s)
Blood Coagulation Factors/therapeutic use , Blood Substitutes/therapeutic use , Platelet Transfusion/methods , Recombinant Proteins/therapeutic use , Blood Coagulation Factors/pharmacology , Blood Substitutes/pharmacology , Hematopoietic Stem Cell Transplantation , Humans , Recombinant Proteins/pharmacology
11.
Adv Exp Med Biol ; 566: 397-401, 2005.
Article in English | MEDLINE | ID: mdl-16594178

ABSTRACT

Acellular free hemoglobin-based oxygen carriers (HBOC) are being developed as red cell substitutes. However, following intravenous administration of some HBOC, decreased systemic blood flow and decreased functional capillary density have been observed. In isolated blood vessels, hemoglobin (Hb) in solution free of erythrocyte membranes has been shown to elicit vascular contraction. Therefore, the decreased blood flow and functional capillary density may be due to inherent vasoactive property of native Hb. There are two plausible mechanisms for the Hb-mediated vasoconstriction: nitrosylation of heme-irons and S-nitrosation of reactive beta-chain cysteines (Cys93beta). In this study, we investigated whether Hb Cys93beta thiols play a role in Hb-mediated vascular contraction using functional bioassays with isolated rat thoracic aorta. To better define the roles of globin thiols and heme-iron, Hbs modified at the heme-iron and/or Cys93beta sites were prepared and their vasoactivities tested. In addition, vasoactivities of natural heme proteins with heme and/or cysteine sites unavailable for NO reaction were also examined.


Subject(s)
Blood Flow Velocity/drug effects , Blood Substitutes/administration & dosage , Vasoconstriction/drug effects , Alkylation , Animals , Aorta, Thoracic/drug effects , Aorta, Thoracic/physiology , Binding Sites , Blood Substitutes/chemistry , Blood Substitutes/metabolism , Blood Substitutes/toxicity , Cysteine/chemistry , Heme/chemistry , Hemoglobins/administration & dosage , Hemoglobins/chemistry , Hemoglobins/metabolism , Hemoglobins/toxicity , In Vitro Techniques , Injections, Intravenous , Male , Nitric Oxide/metabolism , Oxygen/administration & dosage , Rats , Rats, Sprague-Dawley , Sulfhydryl Compounds/chemistry
12.
Artif Organs ; 28(9): 795-9, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15320942

ABSTRACT

This article briefly discusses a few key issues related to transfusion, the concept of hemoglobin-based red blood cell substitutes (HBOCs), and some parameters useful in evaluating the current properties of solutions. Potential uses of HBOCs in civilian applications are identified and listed. Use of HBOCs as a hemodiluent for intraoperative autologous blood donation (IAD) is a particular application that has relevance in many surgical settings and this is discussed in some detail. Data from a Phase III clinical trial is presented to show the potential for avoiding the use of allogeneic blood and blood products in a clinical model of large volume red cell use. Extrapolation to a general use model, primarily based in the potential for surgery, will be noted. Some general parametric values of HBOCs are presented. These values are by no means considered optimal for all HBOCs and are subject to exploration, fine tuning, correction, or even rejection.


Subject(s)
Blood Substitutes/therapeutic use , Erythrocyte Transfusion , Hemoglobins/metabolism , Oxygen Compounds/administration & dosage , Clinical Trials, Phase III as Topic , Erythrocyte Transfusion/methods , Humans , Oxygen Compounds/metabolism
13.
Artif Organs ; 28(9): 813-28, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15320945

ABSTRACT

Two distinct approaches are being explored in red blood cell substitute (RCS) development: hemoglobin-based oxygen carriers (HBOCs) and perfluorocarbon-based oxygen carriers (PFBOCs). HBOCs are based on intra- and/or intermolecularly "engineered" human or animal hemoglobins (Hbs), optimized for O2 delivery and longer intravascular circulation. Some are currently being evaluated in Phase II/III clinical studies. PFBOCs are aqueous emulsions of perfluorocarbon derivatives that dissolve relatively large amounts of O2. A PFBOC based on a 60% (wt/vol) emulsion of perfluorooctyl bromide has been evaluated in Phase II/III clinical trials. Although current PFBOC products generally require patients to breathe O2 enriched air, they render certain advantages since they are totally synthetic. This article provides a short review of the basic principles, approaches, and current status of RCS development. Results of preclinical and clinical studies including recent Phase II/III clinical studies are discussed.


Subject(s)
Blood Substitutes/metabolism , Fluorocarbons/pharmacology , Fluorocarbons/therapeutic use , Hemoglobins/pharmacology , Hemoglobins/therapeutic use , Oxygen/administration & dosage , Blood Substitutes/therapeutic use , Clinical Trials, Phase II as Topic , Clinical Trials, Phase III as Topic , Fluorocarbons/adverse effects , Hemoglobins/adverse effects , Humans , Hydrocarbons, Brominated , Oxygen/metabolism , Treatment Outcome
14.
Crit Care ; 8 Suppl 2: S61-4, 2004.
Article in English | MEDLINE | ID: mdl-15196328

ABSTRACT

Transfusable fluids that may be used as alternatives to red blood cell transfusion offer the promise of preserving tissue perfusion and minimizing hypoxic cellular damage, and this promise may soon be fulfilled. Clinical testing of hemoglobin-based oxygen carriers has faced and met challenges involving molecular design, safety, efficacy, and regulatory requirements. Three leading candidates have emerged: two human (PolyHeme and HemoLink) and one bovine-based hemoglobin solution (Hemopure). Because a survival benefit has been difficult to demonstrate, avoidance of allogeneic transfusion has been adopted as the standard efficacy end-point for these agents. An update on clinical trial status is provided, and the potential utility of hemoglobin-based oxygen carriers in surgery combined with intraoperative autologous donation is discussed.


Subject(s)
Blood Substitutes/therapeutic use , Animals , Cattle , Erythrocyte Transfusion/adverse effects , Hemoglobins , Humans , Meta-Analysis as Topic
15.
J Am Coll Surg ; 198(3): 373-83; discussion 384-5, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14992738

ABSTRACT

BACKGROUND: The benefits of intraoperative autologous donation (IAD) in reducing the need for allogeneic blood transfusion in surgery have been debated for several years. The purpose of this study was to determine if IAD alone or in conjunction with hemoglobin raffimer (HR) confers a reduction in red cell or blood component transfusion compared with results in standard clinical practice. STUDY DESIGN: The Phase III clinical trial was a multicenter, randomized, double-blind study to determine the efficacy and safety of HR versus 10% pentastarch when used to facilitate IAD in 299 patients undergoing primary coronary artery bypass grafting. The patients received HR or pentastarch as an adjunct to IAD immediately before cardiopulmonary bypass. Results were compared with transfusion requirements for 150 matched patients in the reference group. RESULTS: The frequency of allogeneic RBC transfusion in the HR, pentastarch, and reference groups was 56%, 76%, and 95%, respectively. The number of allogeneic red cell units used was 49 in the HR group, 104 in the pentastarch group, and 480 in the reference group (p < 0.001). The total number of non-RBC units administered was 150 in the HR group, 238 in the pentastarch group, and 270 in the reference group. CONCLUSIONS: In this study, patients treated with HR in conjunction with IAD received fewer transfusions overall and a lower volume of allogeneic RBCs and non-RBC allogeneic blood products than did the two comparison groups. This confers a real benefit on the overall blood supply by decreasing use and increasing availability.


Subject(s)
Blood Transfusion, Autologous , Coronary Artery Bypass/methods , Coronary Stenosis/surgery , Hemoglobins/administration & dosage , Raffinose/analogs & derivatives , Raffinose/administration & dosage , Aged , Blood Substitutes/administration & dosage , Blood Substitutes/adverse effects , Blood Transfusion/statistics & numerical data , Blood Transfusion, Autologous/statistics & numerical data , Coronary Stenosis/blood , Double-Blind Method , Erythrocyte Transfusion/statistics & numerical data , Female , Humans , Hydroxyethyl Starch Derivatives , Male , Middle Aged , Treatment Outcome
16.
Crit Care Med ; 30(9): 2151, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12352060
17.
Am J Surg ; 183(6): 655-8, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12095595

ABSTRACT

BACKGROUND: Since 1991 the authors have offered a course that identifies content deficits, but only provides instruction directed at improving verbal and nonverbal behaviors. We report the outcome of this 10-year effort as success on the certifying examination of the American Board of Surgery between 1991 and 2001. METHODS: Sixteen 5-day courses were scheduled over 10 years. Participants included those who had not taken the oral examination or had failed at least once and invited senior faculty (n = 26). Sites were chosen to replicate the actual examination setting. RESULTS: There were 122 participants, with follow-up data available on 88. Success in the certifying examination after completing the course is 96 percent. CONCLUSIONS: Evaluation of communication deficits and training to improve them is strongly associated with success. Clearly, this course is effective at identifying communication behaviors that are interfering with success on the certifying examination of the American Board of Surgery.


Subject(s)
Certification , Communication , Physicians/standards , Professional Competence , Specialties, Surgical/standards , Specialty Boards , Adult , Female , Humans , Male , Middle Aged , Physician-Patient Relations , Program Development , Program Evaluation
18.
Shock ; 17(5): 423-6, 2002 May.
Article in English | MEDLINE | ID: mdl-12022765

ABSTRACT

Elevated levels of nitric oxide (NO) may be a primary cause of the vascular hyporeactivity (vasoplesia) and refractory hypotension in sepsis. This study was initiated to determine the efficacy of NO scavenging with acellular hemoglobin (Hb) solution in modulating sepsis-mediated vasoplesia. Male Sprague Dawley rats were subjected to sepsis by cecal ligation and puncture (CLP). Twenty-four hours post-CLP, the animals were randomly assigned to one of four groups (n = 5-6 each) and given an intravenous injection of 0.5 mL bovine serum albumin (BSA; 5 g/dL), 0.5 mL human Hb (7g/dL), 50 microL Nomega-nitro L-arginine methyl ester (NAME; 1 M), or both Hb and NAME. Blood pressure (BP), cardiac output, systemic vascular resistance, and vascular reactivity (VR) to norepinephrine (NE; 40 ng/Kg) were assessed before and after an experimental treatment. In some animals, inducible NO synthase (iNOS) mRNA expression was assessed in selected tissue samples harvested at the conclusion of experiment using a reverse transcription-polymerase chain reaction (RT-PCR) method. Treatment with Hb, NAME, or NAME + Hb elicited a significant improvement in mean BP and VR compared with the control (BSA) group (P < 0.05, analysis of variance and Neuman-Keuls tests). Tissue samples from 24-h CLP rats clearly exhibited iNOS gene expression; higher iNOS gene expression in the intestine compared with aorta suggests that the intestine may be a major source of the elevated NO level in this model. In conclusion, NO scavenging with Hb, alone, or in combination with NO synthesis inhibition, appears to be effective in modulating sepsis-mediated vascular hyporeactivity and may reduce complications associated with global NO synthesis inhibition.


Subject(s)
Free Radical Scavengers/metabolism , Nitric Oxide/metabolism , Peritonitis/physiopathology , Sepsis/physiopathology , Vascular Resistance/physiology , Animals , Enzyme Inhibitors/pharmacology , Gene Expression Regulation, Enzymologic/drug effects , Hemodynamics/drug effects , Hemoglobins/pharmacology , Male , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase/drug effects , Nitric Oxide Synthase/genetics , Nitric Oxide Synthase Type II , Norepinephrine/pharmacology , Peritonitis/drug therapy , Rats , Rats, Sprague-Dawley , Sepsis/drug therapy , Serum Albumin, Bovine/pharmacology , Vascular Resistance/drug effects
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