ImportanceSpanish-speaking participants are underrepresented in clinical trials, limiting study g... more ImportanceSpanish-speaking participants are underrepresented in clinical trials, limiting study generalizability and contributing to ongoing health inequity. The Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial intentionally included Spanish-speaking participants.ObjectiveTo describe trial participation and compare clinical and patient-reported outcomes among Spanish-speaking and English-speaking participants with acute appendicitis randomized to antibiotics.Design, Setting, and ParticipantsThis study is a secondary analysis of the CODA trial, a pragmatic randomized trial comparing antibiotic therapy with appendectomy in adult patients with imaging-confirmed appendicitis enrolled at 25 centers across the US from May 1, 2016, to February 28, 2020. The trial was conducted in English and Spanish. All 776 participants randomized to antibiotics are included in this analysis. The data were analyzed from November 15, 2021, through August 24, 2022.InterventionRandomi...
Postoperative thrombotic thrombocytopenic purpura (pTTP) after cardiovascular operations has an a... more Postoperative thrombotic thrombocytopenic purpura (pTTP) after cardiovascular operations has an alarmingly high mortality rate if untreated. Five patients after coronary artery bypass graft (CABG) procedure were diagnosed with pTTP when they were observed to have a persistent thrombocytopenia associated with symptoms of fever, renal insufficiency, thromboembolic events, or altered mental status in conjunction with a microangiopathic hemolytic anemia (MAHA). A guideline for early diagnosis, followed by timely treatment in these cases, is reviewed. A retrospective record review of postoperative patients with thrombocytopenia identified 5 patients that met the criteria for pTTP from 2004 to 2008. We examined these 5 cardiovascular surgical patients in terms of clinical presentation, laboratory data, and outcomes. All patients had the combination of an unexplained thrombocytopenia (platelets < 50,000 mm(3)) in conjunction with a MAHA as determined by the presence of schistocytes. Symptoms of neurologic dysfunction and renal insufficiency developed in all patients. Thromboembolic events were noted in 1 patient. All patients underwent plasmapheresis. In 3 patients, response time to clinical recovery and normalization of hematologic laboratory values after plasmapheresis was 3, 4, and 8 days. Two patients did not recover and died. One patient had a clinical and laboratory recovery after 19 days of plasmapheresis; however, after 11 days, thrombocytopenia with MAHA developed and he died on day 53 from complications related to the operation. Postoperative TTP should be recognized as a possible pathophysiologic mechanism for unexplained postoperative thrombocytopenia and treatment should be initiated once the diagnosis is established.
Recently, with increasing social interests on noise and vibration induced by railway traffic, the... more Recently, with increasing social interests on noise and vibration induced by railway traffic, the application of floating slab track that can efficiently reduce the railway vibration is increasing. In this study, to more accurately understand the dynamic behavior of the floating slab track, a laboratory mock-up test has been performed, and the static and dynamic behaviors at frequency range near the system resonance frequency were explored. Based on the test results, the design of the floating slab track and the structural analysis model used in the design have been verified. The analytic and test results demonstrate that the dominant frequency of the floating slab track occurs at the frequencies between vertical rigid body mode natural frequency and bending mode natural frequency, and the dominant deformation mode is close to the bending mode. This suggests that in the design of the floating slab track, the bending rigidity of the slab and the boundary conditions at slab joints and slab ends should be taken into consideration. Also, the analytic results by the two-dimensional finite element analysis model using Kelvin-Voigt model, such as static and dynamic deflections and force transmissibility, are found in good agreement with the test results, and thus the model used in this study has shown the reliability suitable to be utilized in the design of the floating slab track.
Brief Reports should be submitted online to www.editorialmanager.com/ amsurg. (See details online... more Brief Reports should be submitted online to www.editorialmanager.com/ amsurg. (See details online under ''Instructions for Authors''.) They should be no more than 4 double-spaced pages with no Abstract or sub-headings, with a maximum of four (4) references. If figures are included, they should be limited to two (2). The cost of printing color figures is the responsibility of the author. In general, authors of case reports should use the Brief Report format.
Serial blood draws for the assessment of trauma patients' hemoglobin (sHgb) and hematocrit (sHct)... more Serial blood draws for the assessment of trauma patients' hemoglobin (sHgb) and hematocrit (sHct) is standard practice. A device that would allow for continuous real-time, non-invasive monitoring of hemoglobin and tissue perfusion would potentially improve recognition, monitoring and resuscitation of blood loss. We developed a device utilizing diffuse optical spectroscopy (DOS) technology that simultaneously measures tissue scattering and nearinfrared (NIR) absorption to obtain non-invasive measurements of oxy-(Hb-O 2), deoxyhemoglobin (Hb-R) concentrations and tissue hemoglobin concentration (THC) in an animal model of hypovolemic shock induced by successive blood withdrawals. Intubated New Zealand White rabbits (N = 16) were hemorrhaged via a femoral arterial line every 20 min until a 20% blood loss (10-15 cc kg −1) was achieved to attain hypovolemia. A broadband DOS probe placed on the inner thigh was used to measure muscle concentrations of Hb-O 2 and Hb-R, during blood withdrawal. THC and tissue hemoglobin saturation (S T O 2) were calculated from DOS [Hb-O 2 ] and [Hb-R]. Broadband DOSmeasured values were compared against traditional invasive measurements: systemic sHgb, arterial oxygen saturation (S a O 2) and venous oxygen saturation (S v O 2) drawn from arterial and central venous blood. DOS and traditional invasive measurements versus blood loss were closely correlated (r 2 = 0.96) showing a decline with removal of blood. S T O 2 and [Hb-O 2 ] followed similar trends with hemorrhage, while [Hb-R] remained relatively constant. These measurements may be limited to some extent by the inability to distinguish between hemoglobin and myoglobin contributions to DOS signals in tissue at this time. Broadband DOS provides a potential platform for reliable noninvasive measurements of tissue oxygenated and deoxygenated hemoglobin and
The Journal of Thoracic and Cardiovascular Surgery, 2005
Background: Methods for obtainingreal-time in vivo histologic resolution by means of noninvasive ... more Background: Methods for obtainingreal-time in vivo histologic resolution by means of noninvasive endoscopic optical imaging would be a major advance for thoracic surgical diagnostics and treatment. Optical coherence tomography is a rapidly evolving technology based on near-infrared interferometry that might provide these capabilities. The purpose of this study is to investigate the feasibility of real-time 2and 3-dimensional optical coherence tomographic imaging of airway, pleural, and subpleural lung tissues in normal, inflammatory, and malignant animal models and patients with known or suspected airway malignancy. Methods: Freshly excised lungs and pleural tissue obtained from rabbits with inhalation lung injury and induced empyema, metastatic sarcomas, and pleural sarcomas and from patients with airway disease were imaged by using 2-and 3-dimensional optical coherence tomography with a prototype superluminescent diode optical coherence tomographic system constructed in our laboratory. Lungs and pleural tissue were subsequently processed for standard hematoxylin and eosin histology for comparison with optical coherence tomography. Results: Optical coherence tomographic imaging achieved an ex vivo resolution of 10 m and an in vivo resolution of about 30 m with a depth penetration of 1 to 2 mm with 2-and 3-dimensional reconstruction capabilities. Tumors as small as 500 m were detectable with optical coherence tomography. The acquired images closely matched histologic images, demonstrating details at the level of mucosal layers, glands, alveoli, and respiratory bronchioles. Conclusions: Optical coherence tomography with near-infrared interferometric methods enables near real-time in vivo near-histologic resolution optical imaging. With further advances, optical coherence tomography has the potential for real-time accurate and early pleural and subpleural diagnostics by using small-diameter flexible fiberoptic endoscopic probes for a wide range of thoracic surgical applications.
Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have bee... more Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have been developed for replacement or augmentation of blood transfusion. It is important to monitor in vivo tissue hemoglobin content, total tissue hemoglobin [THb], oxy-and deoxy-hemoglobin concentrations ([OHb], [RHb]), and tissue oxygen saturation (S t O 2 =[OHb]/[THb]×100%) to evaluate effectiveness of HBOC transfusion. We designed and constructed a broadband diffuse optical spectroscopy (DOS) prototype system to measure bulk tissue absorption and scattering spectra between 650 and 1000 nm capable of accurately determining these tissue hemoglobin component concentrations in vivo. Our purpose was to assess the feasibility of using DOS to optically monitor tissue [OHb], [RHb], S t O 2 , and total tissue hemoglobin concentration ([THb]=[OHb]+[RHb]) during HBOC infusion using a rabbit hypovolemic shock model. The DOS prototype probe was placed on the shaved inner thigh muscle of the hind leg to assess concentrations of [OHb], [RHb], [THb], as well as S t O 2. Hemorrhagic shock was induced in intubated New Zealand white rabbits (N=6) by withdrawing blood via a femoral arterial line to 20% blood loss (10-15 cc/kg). Hemoglobin glutamer-200 (Hb-200) 1:1 volume resuscitation was administered following the hemorrhage. These values were compared against traditional invasive measurements, serum hemoglobin concentration (sHGB), systemic blood pressure, heart rate, and blood gases. DOS revealed increases of [THb], [OHb], and tissue hemoglobin oxygen saturation after Hb-200 infusion, while blood total hemoglobin values continued did not increase; we speculate, due to hyperosmolality induced hemodilution. DOS enables noninvasive in vivo monitoring of tissue hemoglobin and oxygenation parameters during shock and volume expansion with HBOC and potentially enables the assessment of efficacy of resuscitation efforts using artificial blood substitutes.
The purpose of this study is to demonstrate the feasibility of broadband diffuse optical spectros... more The purpose of this study is to demonstrate the feasibility of broadband diffuse optical spectroscopy ͑DOS͒ for noninvasive optical monitoring of differentiating patterns of total tissue hemoglobin ͑THC͒, oxy-͑OxyHb͒, and deoxyhemoglobin ͑DeOxyHb͒ concentrations during hypovolemic shock and subsequent fluid replacement with saline and whole blood. The goal of this DOS application is to determine the efficacy of resuscitation efforts at the tissue level rather than currently available indirect and invasive measurements of hemodynamic parameters. 16 New Zealand white rabbits are hemorrhaged 20% of their total blood volume. In resuscitated animals, shed blood volume is replaced with equal volume of crystalloid or whole blood ͑five animals each͒. Physiological variables ͑cardiac output, mean arterial pressure, systemic vascular resistance, hematocrit͒ are measured invasively, while ͑OxyHb͒ and ͑DeOxyHb͒ are measured during the interventions using broadband DOS. During the pure hypovolemic hemorrhages, the decrease in THC is mainly due to the decrease in ͑OxyHb͒, since the decrease in THC due to blood loss results in decreased tissue perfusion, with a resultant increased tissue extraction of oxygen. The hemorrhage with the whole blood resuscitation model shows significant changes in ͑OxyHb͒ during resuscitation phases due to the higher oxygen carrying capacity of whole blood, as opposed to the limited volume replacement effects and the decreased tissue oxygen content from the euvolemic anemia of the saline resuscitation. Broadband DOS noninvasive optical monitoring reveals distinct patterns of total tissue hemoglobin, oxy-, and deoxyhemoglobin during hemorrhage. Further studies are needed to confirm potential clinical utility and accuracy under more complex clinical conditions in animal models and patients.
Hypothesis: With the introduction of the newly mandated restrictions on resident work hours, we e... more Hypothesis: With the introduction of the newly mandated restrictions on resident work hours, we expected improvement in subjective feelings of personal accomplishment and lessened emotional exhaustion and depersonalization. Design: Residents and faculty members completed an anonymous online Maslach Burnout Inventory Human Services Survey (3rd ed; Consulting Psychologist Press Inc, Palo Alto, Calif) and work-hour registry before and after implementation of new restrictions. Setting: Urban, university-based department of surgery. Participants: All house staff (n=37) and faculty (n=27). Intervention: Introduction of new Institutional Standards for Resident Duty Hours 2003. Main Outcome Measure: Resident work hours and levels of emotional exhaustion, perceived degree of depersonalization, and personal accomplishment. Results: Resident work hours per week decreased from 100.7 to 82.6 (PϽ.05) with introduction of the new schedule. Home call and formal educational activity time within working hours (eg, clinical conferences) significantly (PϽ.05) decreased from 11.5 and 4.8 hours to 4.6 and 2.5 hours per week, respectively. Operating room hours, clinic time, and duration of rounds did not show a significant change. Changes in parameters of resident and faculty emotional exhaustion, depersonalization, and personal accomplishment did not show statistical significance (PϾ.05). Conclusions: Despite successful reductions in resident work hours, measures of burnout were not significantly affected. However, important clinical activities such as time spent in the operating room, clinic, and making rounds were maintained. Formal in-hospital education time was reduced.
Necrotizing soft tissue infections are associated with a high mortality rate. We hypothesize that... more Necrotizing soft tissue infections are associated with a high mortality rate. We hypothesize that specific predictors of limb loss and mortality in patients with necrotizing soft tissue infection can be identified on hospital admission. Design: A retrospective cohort study. Setting: A tertiary care center. Patients: Patients with a diagnosis of necrotizing soft tissue infection during a 5-year period (1996-2001) were included. Patients were identified with International Classification of Diseases, Ninth Revision hospital discharge diagnosis codes, and diagnosis was confirmed by medical record review. Interventions: Standard current treatment including early and scheduled repeated debridement, broadspectrum antibiotics, and physiologic and nutritional support was given to all patients. Main Outcome Measures: Limb loss and mortality. Results: One hundred sixty-six patients were identified and included in the study. The overall mortality rate
Background: Since the first reports on indications and outcome for abdominal procedures in the HI... more Background: Since the first reports on indications and outcome for abdominal procedures in the HIV/AIDS patient were published 20 years ago, the epidemiology and presentation of surgical illness have changed remarkably with the advent of new antiviral regimens. A review of the now occasional, but still important, role of the surgeon in contemporary treatment of HIV/AIDS is presented. Data Sources: Information was obtained by PubMed searches of medical journals, examination of reference lists, and Web resources. Study Selection: Articles on operative indications, outcomes, precautions, source of transmission, and pathophysiology of HIV/AIDS were selected. Data Extraction: Data was obtained from peerreviewed articles and references. Data Synthesis: The last 2 decades have seen a decrease in operative mortality from as high as 85% to approximately 15% with a corresponding improvement in morbidity. Surgical emergencies such as appendicitis occur in HIV patients with the same frequency as non-HIV patients and are treated with equivalent results. Concern about transmission of HIV in the operating room has lessened somewhat. Although still a hazard, the probability of HIV transmission with accidental exposure is low, with risks below 0.5% for percutaneous hollow-bore needles and less than 0.1% risk for mucus membrane exposure. Conclusions: Improved surgical outcomes together with of accurate data on the modes and likelihood of accidental transmission of HIV to members of the surgery team have resulted in the treatment of HIV/AIDS patients becoming an accepted part of routine surgical practice.
ImportanceA patient’s belief in the likely success of a treatment may influence outcomes, but thi... more ImportanceA patient’s belief in the likely success of a treatment may influence outcomes, but this has been understudied in surgical trials.ObjectiveTo examine the association between patients’ baseline beliefs about the likelihood of treatment success with outcomes of antibiotics for appendicitis in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial.Design, Setting, and ParticipantsThis was a secondary analysis of the CODA randomized clinical trial. Participants from 25 US medical centers were enrolled between May 3, 2016, and February 5, 2020. Included in the analysis were participants with appendicitis who were randomly assigned to receive antibiotics in the CODA trial. After informed consent but before randomization, participants who were assigned to receive antibiotics responded to a baseline survey including a question about how successful they believed antibiotics could be in treating their appendicitis.InterventionsParticipants were categorized base...
IMPORTANCE In the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial, which... more IMPORTANCE In the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial, which found antibiotics to be noninferior, approximately half of participants randomized to receive antibiotics had outpatient management with hospital discharge within 24 hours. If outpatient management is safe, it could increase convenience and decrease health care use and costs.
ImportanceSpanish-speaking participants are underrepresented in clinical trials, limiting study g... more ImportanceSpanish-speaking participants are underrepresented in clinical trials, limiting study generalizability and contributing to ongoing health inequity. The Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial intentionally included Spanish-speaking participants.ObjectiveTo describe trial participation and compare clinical and patient-reported outcomes among Spanish-speaking and English-speaking participants with acute appendicitis randomized to antibiotics.Design, Setting, and ParticipantsThis study is a secondary analysis of the CODA trial, a pragmatic randomized trial comparing antibiotic therapy with appendectomy in adult patients with imaging-confirmed appendicitis enrolled at 25 centers across the US from May 1, 2016, to February 28, 2020. The trial was conducted in English and Spanish. All 776 participants randomized to antibiotics are included in this analysis. The data were analyzed from November 15, 2021, through August 24, 2022.InterventionRandomi...
Postoperative thrombotic thrombocytopenic purpura (pTTP) after cardiovascular operations has an a... more Postoperative thrombotic thrombocytopenic purpura (pTTP) after cardiovascular operations has an alarmingly high mortality rate if untreated. Five patients after coronary artery bypass graft (CABG) procedure were diagnosed with pTTP when they were observed to have a persistent thrombocytopenia associated with symptoms of fever, renal insufficiency, thromboembolic events, or altered mental status in conjunction with a microangiopathic hemolytic anemia (MAHA). A guideline for early diagnosis, followed by timely treatment in these cases, is reviewed. A retrospective record review of postoperative patients with thrombocytopenia identified 5 patients that met the criteria for pTTP from 2004 to 2008. We examined these 5 cardiovascular surgical patients in terms of clinical presentation, laboratory data, and outcomes. All patients had the combination of an unexplained thrombocytopenia (platelets < 50,000 mm(3)) in conjunction with a MAHA as determined by the presence of schistocytes. Symptoms of neurologic dysfunction and renal insufficiency developed in all patients. Thromboembolic events were noted in 1 patient. All patients underwent plasmapheresis. In 3 patients, response time to clinical recovery and normalization of hematologic laboratory values after plasmapheresis was 3, 4, and 8 days. Two patients did not recover and died. One patient had a clinical and laboratory recovery after 19 days of plasmapheresis; however, after 11 days, thrombocytopenia with MAHA developed and he died on day 53 from complications related to the operation. Postoperative TTP should be recognized as a possible pathophysiologic mechanism for unexplained postoperative thrombocytopenia and treatment should be initiated once the diagnosis is established.
Recently, with increasing social interests on noise and vibration induced by railway traffic, the... more Recently, with increasing social interests on noise and vibration induced by railway traffic, the application of floating slab track that can efficiently reduce the railway vibration is increasing. In this study, to more accurately understand the dynamic behavior of the floating slab track, a laboratory mock-up test has been performed, and the static and dynamic behaviors at frequency range near the system resonance frequency were explored. Based on the test results, the design of the floating slab track and the structural analysis model used in the design have been verified. The analytic and test results demonstrate that the dominant frequency of the floating slab track occurs at the frequencies between vertical rigid body mode natural frequency and bending mode natural frequency, and the dominant deformation mode is close to the bending mode. This suggests that in the design of the floating slab track, the bending rigidity of the slab and the boundary conditions at slab joints and slab ends should be taken into consideration. Also, the analytic results by the two-dimensional finite element analysis model using Kelvin-Voigt model, such as static and dynamic deflections and force transmissibility, are found in good agreement with the test results, and thus the model used in this study has shown the reliability suitable to be utilized in the design of the floating slab track.
Brief Reports should be submitted online to www.editorialmanager.com/ amsurg. (See details online... more Brief Reports should be submitted online to www.editorialmanager.com/ amsurg. (See details online under ''Instructions for Authors''.) They should be no more than 4 double-spaced pages with no Abstract or sub-headings, with a maximum of four (4) references. If figures are included, they should be limited to two (2). The cost of printing color figures is the responsibility of the author. In general, authors of case reports should use the Brief Report format.
Serial blood draws for the assessment of trauma patients' hemoglobin (sHgb) and hematocrit (sHct)... more Serial blood draws for the assessment of trauma patients' hemoglobin (sHgb) and hematocrit (sHct) is standard practice. A device that would allow for continuous real-time, non-invasive monitoring of hemoglobin and tissue perfusion would potentially improve recognition, monitoring and resuscitation of blood loss. We developed a device utilizing diffuse optical spectroscopy (DOS) technology that simultaneously measures tissue scattering and nearinfrared (NIR) absorption to obtain non-invasive measurements of oxy-(Hb-O 2), deoxyhemoglobin (Hb-R) concentrations and tissue hemoglobin concentration (THC) in an animal model of hypovolemic shock induced by successive blood withdrawals. Intubated New Zealand White rabbits (N = 16) were hemorrhaged via a femoral arterial line every 20 min until a 20% blood loss (10-15 cc kg −1) was achieved to attain hypovolemia. A broadband DOS probe placed on the inner thigh was used to measure muscle concentrations of Hb-O 2 and Hb-R, during blood withdrawal. THC and tissue hemoglobin saturation (S T O 2) were calculated from DOS [Hb-O 2 ] and [Hb-R]. Broadband DOSmeasured values were compared against traditional invasive measurements: systemic sHgb, arterial oxygen saturation (S a O 2) and venous oxygen saturation (S v O 2) drawn from arterial and central venous blood. DOS and traditional invasive measurements versus blood loss were closely correlated (r 2 = 0.96) showing a decline with removal of blood. S T O 2 and [Hb-O 2 ] followed similar trends with hemorrhage, while [Hb-R] remained relatively constant. These measurements may be limited to some extent by the inability to distinguish between hemoglobin and myoglobin contributions to DOS signals in tissue at this time. Broadband DOS provides a potential platform for reliable noninvasive measurements of tissue oxygenated and deoxygenated hemoglobin and
The Journal of Thoracic and Cardiovascular Surgery, 2005
Background: Methods for obtainingreal-time in vivo histologic resolution by means of noninvasive ... more Background: Methods for obtainingreal-time in vivo histologic resolution by means of noninvasive endoscopic optical imaging would be a major advance for thoracic surgical diagnostics and treatment. Optical coherence tomography is a rapidly evolving technology based on near-infrared interferometry that might provide these capabilities. The purpose of this study is to investigate the feasibility of real-time 2and 3-dimensional optical coherence tomographic imaging of airway, pleural, and subpleural lung tissues in normal, inflammatory, and malignant animal models and patients with known or suspected airway malignancy. Methods: Freshly excised lungs and pleural tissue obtained from rabbits with inhalation lung injury and induced empyema, metastatic sarcomas, and pleural sarcomas and from patients with airway disease were imaged by using 2-and 3-dimensional optical coherence tomography with a prototype superluminescent diode optical coherence tomographic system constructed in our laboratory. Lungs and pleural tissue were subsequently processed for standard hematoxylin and eosin histology for comparison with optical coherence tomography. Results: Optical coherence tomographic imaging achieved an ex vivo resolution of 10 m and an in vivo resolution of about 30 m with a depth penetration of 1 to 2 mm with 2-and 3-dimensional reconstruction capabilities. Tumors as small as 500 m were detectable with optical coherence tomography. The acquired images closely matched histologic images, demonstrating details at the level of mucosal layers, glands, alveoli, and respiratory bronchioles. Conclusions: Optical coherence tomography with near-infrared interferometric methods enables near real-time in vivo near-histologic resolution optical imaging. With further advances, optical coherence tomography has the potential for real-time accurate and early pleural and subpleural diagnostics by using small-diameter flexible fiberoptic endoscopic probes for a wide range of thoracic surgical applications.
Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have bee... more Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have been developed for replacement or augmentation of blood transfusion. It is important to monitor in vivo tissue hemoglobin content, total tissue hemoglobin [THb], oxy-and deoxy-hemoglobin concentrations ([OHb], [RHb]), and tissue oxygen saturation (S t O 2 =[OHb]/[THb]×100%) to evaluate effectiveness of HBOC transfusion. We designed and constructed a broadband diffuse optical spectroscopy (DOS) prototype system to measure bulk tissue absorption and scattering spectra between 650 and 1000 nm capable of accurately determining these tissue hemoglobin component concentrations in vivo. Our purpose was to assess the feasibility of using DOS to optically monitor tissue [OHb], [RHb], S t O 2 , and total tissue hemoglobin concentration ([THb]=[OHb]+[RHb]) during HBOC infusion using a rabbit hypovolemic shock model. The DOS prototype probe was placed on the shaved inner thigh muscle of the hind leg to assess concentrations of [OHb], [RHb], [THb], as well as S t O 2. Hemorrhagic shock was induced in intubated New Zealand white rabbits (N=6) by withdrawing blood via a femoral arterial line to 20% blood loss (10-15 cc/kg). Hemoglobin glutamer-200 (Hb-200) 1:1 volume resuscitation was administered following the hemorrhage. These values were compared against traditional invasive measurements, serum hemoglobin concentration (sHGB), systemic blood pressure, heart rate, and blood gases. DOS revealed increases of [THb], [OHb], and tissue hemoglobin oxygen saturation after Hb-200 infusion, while blood total hemoglobin values continued did not increase; we speculate, due to hyperosmolality induced hemodilution. DOS enables noninvasive in vivo monitoring of tissue hemoglobin and oxygenation parameters during shock and volume expansion with HBOC and potentially enables the assessment of efficacy of resuscitation efforts using artificial blood substitutes.
The purpose of this study is to demonstrate the feasibility of broadband diffuse optical spectros... more The purpose of this study is to demonstrate the feasibility of broadband diffuse optical spectroscopy ͑DOS͒ for noninvasive optical monitoring of differentiating patterns of total tissue hemoglobin ͑THC͒, oxy-͑OxyHb͒, and deoxyhemoglobin ͑DeOxyHb͒ concentrations during hypovolemic shock and subsequent fluid replacement with saline and whole blood. The goal of this DOS application is to determine the efficacy of resuscitation efforts at the tissue level rather than currently available indirect and invasive measurements of hemodynamic parameters. 16 New Zealand white rabbits are hemorrhaged 20% of their total blood volume. In resuscitated animals, shed blood volume is replaced with equal volume of crystalloid or whole blood ͑five animals each͒. Physiological variables ͑cardiac output, mean arterial pressure, systemic vascular resistance, hematocrit͒ are measured invasively, while ͑OxyHb͒ and ͑DeOxyHb͒ are measured during the interventions using broadband DOS. During the pure hypovolemic hemorrhages, the decrease in THC is mainly due to the decrease in ͑OxyHb͒, since the decrease in THC due to blood loss results in decreased tissue perfusion, with a resultant increased tissue extraction of oxygen. The hemorrhage with the whole blood resuscitation model shows significant changes in ͑OxyHb͒ during resuscitation phases due to the higher oxygen carrying capacity of whole blood, as opposed to the limited volume replacement effects and the decreased tissue oxygen content from the euvolemic anemia of the saline resuscitation. Broadband DOS noninvasive optical monitoring reveals distinct patterns of total tissue hemoglobin, oxy-, and deoxyhemoglobin during hemorrhage. Further studies are needed to confirm potential clinical utility and accuracy under more complex clinical conditions in animal models and patients.
Hypothesis: With the introduction of the newly mandated restrictions on resident work hours, we e... more Hypothesis: With the introduction of the newly mandated restrictions on resident work hours, we expected improvement in subjective feelings of personal accomplishment and lessened emotional exhaustion and depersonalization. Design: Residents and faculty members completed an anonymous online Maslach Burnout Inventory Human Services Survey (3rd ed; Consulting Psychologist Press Inc, Palo Alto, Calif) and work-hour registry before and after implementation of new restrictions. Setting: Urban, university-based department of surgery. Participants: All house staff (n=37) and faculty (n=27). Intervention: Introduction of new Institutional Standards for Resident Duty Hours 2003. Main Outcome Measure: Resident work hours and levels of emotional exhaustion, perceived degree of depersonalization, and personal accomplishment. Results: Resident work hours per week decreased from 100.7 to 82.6 (PϽ.05) with introduction of the new schedule. Home call and formal educational activity time within working hours (eg, clinical conferences) significantly (PϽ.05) decreased from 11.5 and 4.8 hours to 4.6 and 2.5 hours per week, respectively. Operating room hours, clinic time, and duration of rounds did not show a significant change. Changes in parameters of resident and faculty emotional exhaustion, depersonalization, and personal accomplishment did not show statistical significance (PϾ.05). Conclusions: Despite successful reductions in resident work hours, measures of burnout were not significantly affected. However, important clinical activities such as time spent in the operating room, clinic, and making rounds were maintained. Formal in-hospital education time was reduced.
Necrotizing soft tissue infections are associated with a high mortality rate. We hypothesize that... more Necrotizing soft tissue infections are associated with a high mortality rate. We hypothesize that specific predictors of limb loss and mortality in patients with necrotizing soft tissue infection can be identified on hospital admission. Design: A retrospective cohort study. Setting: A tertiary care center. Patients: Patients with a diagnosis of necrotizing soft tissue infection during a 5-year period (1996-2001) were included. Patients were identified with International Classification of Diseases, Ninth Revision hospital discharge diagnosis codes, and diagnosis was confirmed by medical record review. Interventions: Standard current treatment including early and scheduled repeated debridement, broadspectrum antibiotics, and physiologic and nutritional support was given to all patients. Main Outcome Measures: Limb loss and mortality. Results: One hundred sixty-six patients were identified and included in the study. The overall mortality rate
Background: Since the first reports on indications and outcome for abdominal procedures in the HI... more Background: Since the first reports on indications and outcome for abdominal procedures in the HIV/AIDS patient were published 20 years ago, the epidemiology and presentation of surgical illness have changed remarkably with the advent of new antiviral regimens. A review of the now occasional, but still important, role of the surgeon in contemporary treatment of HIV/AIDS is presented. Data Sources: Information was obtained by PubMed searches of medical journals, examination of reference lists, and Web resources. Study Selection: Articles on operative indications, outcomes, precautions, source of transmission, and pathophysiology of HIV/AIDS were selected. Data Extraction: Data was obtained from peerreviewed articles and references. Data Synthesis: The last 2 decades have seen a decrease in operative mortality from as high as 85% to approximately 15% with a corresponding improvement in morbidity. Surgical emergencies such as appendicitis occur in HIV patients with the same frequency as non-HIV patients and are treated with equivalent results. Concern about transmission of HIV in the operating room has lessened somewhat. Although still a hazard, the probability of HIV transmission with accidental exposure is low, with risks below 0.5% for percutaneous hollow-bore needles and less than 0.1% risk for mucus membrane exposure. Conclusions: Improved surgical outcomes together with of accurate data on the modes and likelihood of accidental transmission of HIV to members of the surgery team have resulted in the treatment of HIV/AIDS patients becoming an accepted part of routine surgical practice.
ImportanceA patient’s belief in the likely success of a treatment may influence outcomes, but thi... more ImportanceA patient’s belief in the likely success of a treatment may influence outcomes, but this has been understudied in surgical trials.ObjectiveTo examine the association between patients’ baseline beliefs about the likelihood of treatment success with outcomes of antibiotics for appendicitis in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial.Design, Setting, and ParticipantsThis was a secondary analysis of the CODA randomized clinical trial. Participants from 25 US medical centers were enrolled between May 3, 2016, and February 5, 2020. Included in the analysis were participants with appendicitis who were randomly assigned to receive antibiotics in the CODA trial. After informed consent but before randomization, participants who were assigned to receive antibiotics responded to a baseline survey including a question about how successful they believed antibiotics could be in treating their appendicitis.InterventionsParticipants were categorized base...
IMPORTANCE In the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial, which... more IMPORTANCE In the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial, which found antibiotics to be noninferior, approximately half of participants randomized to receive antibiotics had outpatient management with hospital discharge within 24 hours. If outpatient management is safe, it could increase convenience and decrease health care use and costs.
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Papers by Darin Saltzman