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Papers by Lewis Kaplan

Surgical Infections

Several surgically relevant conditions are directly or indirectly influenced by the human microbi... more Several surgically relevant conditions are directly or indirectly influenced by the human microbiome. Different microbiomes may be found within, or along, specific organs and intra-organ variation is common. Such variations include those found along the course of the gastrointestinal tract as well as those on different regions of the skin. A variety of physiologic stressors and care interventions may derange the native microbiome. A deranged microbiome is termed a dysbiome and is characterized by decreased diversity and an increase in the proportion of potentially pathogenic organisms; the elaboration of virulence factors coupled with clinical consequences defines a pathobiome. Specific conditions such as Clostridium difficile colitis, inflammatory bowel disease, obesity, and diabetes mellitus are tightly linked to a dysbiome or pathobiome. Additionally, massive transfusion after injury appears to derange the gastrointestinal microbiome as well. This review explores what is known about these surgically relevant clinical conditions to chart how non-surgical interventions may support surgical undertakings or potentially reduce the need for operation.

Principles of Adult Surgical Critical Care, 2016

Surgical Infections Case Reports, 2017

Background: Peripheral arterial disease may be complicated by tissue ischemia and subsequent gang... more Background: Peripheral arterial disease may be complicated by tissue ischemia and subsequent gangrene. When tissue gangrene is accompanied by septic shock in a patient with comorbid medical conditions and compromised physiology, emergency operation may trigger cardiac complications of non-cardiac surgery. Such patients benefit from resuscitation and cardiac optimization prior to operative intervention. Conclusion: Cryoamputation provides a non-surgical alternative to immediate amputation, arrests bacterial growth, has no known resistance induction, achieves anesthesia, and excludes ischemic tissue and its metabolic byproducts from the circulation. This allows patient resuscitation, metabolic abnormality correction, and cardiac performance optimization prior to definitive operation.

Critical Care Medicine, 2021

This is an open-access article distributed under the terms of the Creative Commons Attribution-No... more This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. OBJECTIVES: Critical care medicine is a natural environment for machine learning approaches to improve outcomes for critically ill patients as admissions to ICUs generate vast amounts of data. However, technical, legal, ethical, and privacy concerns have so far limited the critical care medicine community from making these data readily available. The Society of Critical Care Medicine and the European Society of Intensive Care Medicine have identified ICU patient data sharing as one of the priorities under their Joint Data Science Collaboration. To encourage ICUs worldwide to share their patient data responsibly, we now describe the development and release of Amsterdam University Medical Centers Database (AmsterdamUMCdb), the first freely available critical care database in full compliance with privacy laws from both the United States and Europe, as an example of the feasibility of sharing complex critical care data. SETTING: University hospital ICU. SUBJECTS: Data from ICU patients admitted between 2003 and 2016. INTERVENTIONS: We used a risk-based deidentification strategy to maintain data utility while preserving privacy. In addition, we implemented contractual and governance processes, and a communication strategy. Patient organizations, supporting hospitals, and experts on ethics and privacy audited these processes and the database. MEASUREMENTS AND MAIN RESULTS: AmsterdamUMCdb contains approximately 1 billion clinical data points from 23,106 admissions of 20,109 patients. The privacy audit concluded that reidentification is not reasonably likely, and AmsterdamUMCdb can therefore be considered as anonymous information, both in the context of the U.S. Health Insurance Portability and Accountability Act and the European General Data Protection Regulation. The ethics audit concluded that responsible data sharing imposes minimal burden, whereas the potential benefit is tremendous. CONCLUSIONS: Technical, legal, ethical, and privacy challenges related to responsible data sharing can be addressed using a multidisciplinary approach. A risk-based deidentification strategy, that complies with both U.S. and European privacy regulations, should be the preferred approach to releasing ICU patient data. This supports the shared Society of Critical Care Medicine and European Society of Intensive Care Medicine vision to

JAMA Surgery, 2019

IMPORTANCE Current therapies for traumatic blood loss focus on hemorrhage control and blood volum... more IMPORTANCE Current therapies for traumatic blood loss focus on hemorrhage control and blood volume replacement. Severe hemorrhagic shock, however, is associated with a state of arginine vasopressin (AVP) deficiency, and supplementation of this hormone may decrease the need for blood products in resuscitation. OBJECTIVE To determine whether low-dose supplementation of AVP in patients with trauma (hereinafter referred to as trauma patients) and with hemorrhagic shock decreases their need for transfused blood products during resuscitation. DESIGN, SETTING, AND PARTICIPANTS This randomized, double-blind placebo-controlled clinical trial included adult trauma patients (aged 18-65 years) who received at least 6 U of any blood product within 12 hours of injury at a single urban level 1 trauma center from May 1, 2013, through May 31, 2017. Exclusion criteria consisted of prehospital cardiopulmonary resuscitation, emergency department thoracotomy, corticosteroid use, chronic renal insufficiency, coronary artery disease, traumatic brain injury requiring any neurosurgical intervention, pregnancy, prisoner status, or AVP administration before enrollment. Data were analyzed from May 1, 2013, through May 31, 2017, using intention to treat and per protocol. INTERVENTIONS After administration of an AVP bolus (4 U) or placebo, participants received AVP (Յ0.04 U/min) or placebo for 48 hours to maintain a mean arterial blood pressure of at least 65 mm Hg. MAIN OUTCOMES The primary outcome was total volume of blood product transfused. Secondary end points included total volume of crystalloid transfused, vasopressor requirements, secondary complications, and 30-day mortality. RESULTS One hundred patients underwent randomization (49 to the AVP group and 51 to the placebo group). Patients were primarily young (median age, 27 years [interquartile range {IQR}, 22-25 years]) and male (n = 93) with penetrating trauma (n = 79). Cohort characteristics before randomization were well balanced. At 48 hours, patients who received AVP required significantly less blood products (median, 1.4 [IQR, 0.5-2.6] vs 2.9 [IQR, 1.1-4.8] L; P = .01) but did not differ in requirements for crystalloids (median, 9.9 [IQR, 7.9-13.0] vs 11.0 [8.9-15.0] L; P = .22) or vasopressors (median, 400 [IQR, 0-5900] vs 1400 [IQR, 200-7600] equivalent units; P = .22). Although the groups had similar rates of mortality (6 of 49 [12%] vs 6 of 51 [12%]; P = .94) and total complications (24 of 44 [55%] vs 30 of 47 [64%]; P = .37), the AVP group had less deep venous thrombosis (5 of 44 [11%] vs 16 of 47 [34%]; P = .02). CONCLUSIONS AND RELEVANCE Low-dose AVP during the resuscitation of trauma patients in hemorrhagic shock decreases blood product requirements. Additional research is necessary to determine whether including AVP improves morbidity or mortality.

Critical care research and practice, 2018

Critically ill patients are often evaluated for an intra-abdominal catastrophe. In the absence of... more Critically ill patients are often evaluated for an intra-abdominal catastrophe. In the absence of a preoperative diagnosis, abdominal exploration may be offered despite desperate circumstances. We hypothesize that (1) abdominal exploration for such patients is associated with a high mortality and (2) commonly obtained physiologic measures at laparotomy anticipate mortality. All acute care surgery (ACS) patients undergoing emergency laparotomy at a quaternary referral center during a 3-year period were reviewed. Inclusion was defined by emergency laparotomy in the operating room (OR) in a patient with an American Society of Anesthesiologists (ASA) score ≥4 or bedside laparotomy in the ICU (BSL). Mortality was the primary endpoint and was stratified by demographics, admitting service, surgical findings, and physiology. Comparisons between OR and BSL were by Fisher's exact and Mann-Whitney tests. 144 patients underwent emergency laparotomy (45 BSL vs. 99 OR). Overall mortality was ...

Trauma Surgery & Acute Care Open, 2017

World journal of emergency surgery : WJES, 2017

Antimicrobial Stewardship Programs (ASPs) have been promoted to optimize antimicrobial usage and ... more Antimicrobial Stewardship Programs (ASPs) have been promoted to optimize antimicrobial usage and patient outcomes, and to reduce the emergence of antimicrobial-resistant organisms. However, the best strategies for an ASP are not definitively established and are likely to vary based on local culture, policy, and routine clinical practice, and probably limited resources in middle-income countries. The aim of this study is to evaluate structures and resources of antimicrobial stewardship teams (ASTs) in surgical departments from different regions of the world. A cross-sectional web-based survey was conducted in 2016 on 173 physicians who participated in the AGORA (Antimicrobials: A Global Alliance for Optimizing their Rational Use in Intra-Abdominal Infections) project and on 658 international experts in the fields of ASPs, infection control, and infections in surgery. The response rate was 19.4%. One hundred fifty-six (98.7%) participants stated their hospital had a multidisciplinary ...

JAMA, 2016

IMPORTANCE More than 100 million units of blood are collected worldwide each year, yet the indica... more IMPORTANCE More than 100 million units of blood are collected worldwide each year, yet the indication for red blood cell (RBC) transfusion and the optimal length of RBC storage prior to transfusion are uncertain. OBJECTIVE To provide recommendations for the target hemoglobin level for RBC transfusion among hospitalized adult patients who are hemodynamically stable and the length of time RBCs should be stored prior to transfusion. EVIDENCE REVIEW Reference librarians conducted a literature search for randomized clinical trials (RCTs) evaluating hemoglobin thresholds for RBC transfusion (1950-May 2016) and RBC storage duration (1948-May 2016) without language restrictions. The results were summarized using the Grading of Recommendations Assessment, Development and Evaluation method. For RBC transfusion thresholds, 31 RCTs included 12 587 participants and compared restrictive thresholds (transfusion not indicated until the hemoglobin level is 7-8 g/dL) with liberal thresholds (transfusion not indicated until the hemoglobin level is 9-10 g/dL). The summary estimates across trials demonstrated that restrictive RBC transfusion thresholds were not associated with higher rates of adverse clinical outcomes, including 30-day mortality, myocardial infarction, cerebrovascular accident, rebleeding, pneumonia, or thromboembolism. For RBC storage duration, 13 RCTs included 5515 participants randomly allocated to receive fresher blood or standard-issue blood. These RCTs demonstrated that fresher blood did not improve clinical outcomes. FINDINGS It is good practice to consider the hemoglobin level, the overall clinical context, patient preferences, and alternative therapies when making transfusion decisions regarding an individual patient. Recommendation 1: a restrictive RBC transfusion threshold in which the transfusion is not indicated until the hemoglobin level is 7 g/dL is recommended for hospitalized adult patients who are hemodynamically stable, including critically ill patients, rather than when the hemoglobin level is 10 g/dL (strong recommendation, moderate quality evidence). A restrictive RBC transfusion threshold of 8 g/dL is recommended for patients undergoing orthopedic surgery, cardiac surgery, and those with preexisting cardiovascular disease (strong recommendation, moderate quality evidence). The restrictive transfusion threshold of 7 g/dL is likely comparable with 8 g/dL, but RCT evidence is not available for all patient categories. These recommendations do not apply to patients with acute coronary syndrome, severe thrombocytopenia (patients treated for hematological or oncological reasons who are at risk of bleeding), and chronic transfusion-dependent anemia (not recommended due to insufficient evidence). Recommendation 2: patients, including neonates, should receive RBC units selected at any point within their licensed dating period (standard issue) rather than limiting patients to transfusion of only fresh (storage length: <10 days) RBC units (strong recommendation, moderate quality evidence). CONCLUSIONS AND RELEVANCE Research in RBC transfusion medicine has significantly advanced the science in recent years and provides high-quality evidence to inform guidelines. A restrictive transfusion threshold is safe in most clinical settings and the current blood banking practices of using standard-issue blood should be continued.

Transfusion, Jan 11, 2016

Massive transfusion practices have undergone several recent developments. We sought to examine in... more Massive transfusion practices have undergone several recent developments. We sought to examine institutional practices guiding hemostatic resuscitation in the setting of massive hemorrhage. A 37-question online survey was sent to American Association for the Surgery of Trauma members. A total of 191 surgeons from 125 institutions completed the survey. Level I and II centers composed 70 and 18% of responding sites, respectively. A total of 123 institutions have a massive transfusion protocol (MTP); 54% report having an MTP for less than 5 years. The number of coolers and units of red blood cells, plasma, and platelets are highly variable. Tranexamic acid is part of the MTP at 64% of centers; 26% continue to use recombinant activated Factor VII. MTP activation occurs more than five times per month at 32% of centers. MTPs are utilized for nontrauma patients in 82% of institutions. Point-of-care prothrombin time, international normalized ratio, and partial thromboplastin time testing is...

World journal of emergency surgery : WJES, 2016

Intra-abdominal infections (IAI) are an important cause of morbidity and are frequently associate... more Intra-abdominal infections (IAI) are an important cause of morbidity and are frequently associated with poor prognosis, particularly in high-risk patients. The cornerstones in the management of complicated IAIs are timely effective source control with appropriate antimicrobial therapy. Empiric antimicrobial therapy is important in the management of intra-abdominal infections and must be broad enough to cover all likely organisms because inappropriate initial antimicrobial therapy is associated with poor patient outcomes and the development of bacterial resistance. The overuse of antimicrobials is widely accepted as a major driver of some emerging infections (such as C. difficile), the selection of resistant pathogens in individual patients, and for the continued development of antimicrobial resistance globally. The growing emergence of multi-drug resistant organisms and the limited development of new agents available to counteract them have caused an impending crisis with alarming i...

Intensive Care Medicine, 2009

The optimal method of ventilating and oxygenating patients with ALI or ARDS remains a hotly debat... more The optimal method of ventilating and oxygenating patients with ALI or ARDS remains a hotly debated topic. Recent advances in lung injury research have refocused clinical attention on reduced tidal volumes and limited peak airway pressures in order to diminish the impact of gas delivery to lungs with abnormal compliance, volume, and regional time constants [1]. Despite such focus, the benefits of a pressure-limited or volume-limited strategy for ALI remain controversial [2]. From the midst of multiple ABC = arterial blood gas; ALI = acute lung injury; APRV = airway pressure release ventilation; ARDS = adult respiratory distress syndrome; BIS = bispectral index; BSA = body surface area; CPAP = continuous positive airway pressure; FiO 2 , fractional inspired oxygen; ICU = intensive care unit; IRV = inverse ratio ventilation; PAC = pulmonary artery catheter; PCV = pressure-controlled ventilation; PEEP = positive end-expiratory pressure; S v O 2 = mixed venous oxygen saturation.

Anaesthesiology intensive therapy, Jan 27, 2014

Secondary intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are closely... more Secondary intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are closely related to fluid resuscitation. IAH causes major deterioration of the cardiac function by affecting preload, contractility and afterload. The aim of this review is to discuss the different interactions between IAH, ACS and resuscitation, and to explore a new hypothesis with regard to damage control resuscitation, permissive hypotension and global increased permeability syndrome. Review of the relevant literature via PubMed search. The recognition of the association between the development of ACS and resuscitation urged the need for new approach in traumatic shock management. Over a decade after wide spread application of damage control surgery damage control resuscitation was developed. DCR differs from previous resuscitation approaches by attempting an earlier and more aggressive correction of coagulopathy, as well as metabolic derangements like acidosis and hypothermia, often referred...

Journal of Trauma and Acute Care Surgery, 2012

BACKGROUND: Airway pressure release ventilation (APRV) is used both as a rescue therapy for patie... more BACKGROUND: Airway pressure release ventilation (APRV) is used both as a rescue therapy for patients with acute lung injury and as a primary mode of ventilation. Unlike assist-control volume (ACV) ventilation that uses spontaneous breathing trials, APRV weaning consists of gradual decreases in supporting pressure. We hypothesized that the APRV weaning process increases total ventilator days compared with those of spontaneous breathing trialsYbased weaning. METHODS: A retrospective review of a Level I trauma center's database identified trauma admissions from January 1, 2007, to December 31, 2010, which required mechanical ventilation for more than 24 hours and survived. Demographics, injuries, in-hospital complications, ventilation mode(s), and total ventilator days were abstracted. RESULTS: A total of 362 patients fulfilled study entry criteria; 53 patients with more than one ventilator mode change were excluded. Seventy-five patients were successfully liberated from mechanical ventilation on APRV and 234 on ACV. The APRVand ACV groups, respectively, were similar in age (46.1 vs. 44.6 years) and sex (72% vs. 73% male) but differed in Injury Severity Score (20.8 vs. 17.5; p = 0.03). Patients on APRV had higher rates of abdominal compartment syndrome (6.7% vs. 0.8%, p = 0.003) and were more likely to have a higher chest Abbreviated Injury Scale (AIS) score Q3 (57.3% vs. 30.8%, p G 0.001). Ventilator days were significantly greater in the APRV group (19.6 vs. 10.7 days, p G 0.001). Multiple regression was performed to adjust for the clinical differences between the two groups, identifying APRV as an independent predictor for increased number of ventilator days (B = 6.2 T 1.5, p G 0.001) in addition to male sex, abdomen AIS score of 3 or higher, spine AIS score of 3 or higher, acute renal failure, and sepsis. CONCLUSION: APRV is frequently used for patients who are more severely injured or who develop in-hospital complications such as pneumonia. However, after controlling for potential confounding factors in a multiple regression model, the APRV mode itself seems to increase ventilator days.

Imaging the ICU Patient, 2014

Surgical Infections, 2007

The Journal of Trauma: Injury, Infection, and Critical Care, 2004

Background: As HBOC-201 improves outcome in animals with hemorrhagic shock (HS), we compared HBOC... more Background: As HBOC-201 improves outcome in animals with hemorrhagic shock (HS), we compared HBOC-201 and HEX (used by U.S. military special operations forces) in a swine model of delayed evacuation and uncontrolled HS. Methods: Twenty-four Yucatan pigs underwent a grade III liver injury and were resuscitated with HBOC-201, HEX, or no fluid (NON). Additional infusions were given for hypotension or tachycardia. After 4 hours, the liver was repaired; IV fluids and blood transfusions were administered. Pigs were monitored for 72 hours. Results: Survival was 7/8, 1/8, and 1/8 in HBOC-201-, HEX-, and NON-resuscitated pigs, respectively. Compared with HEX, HBOC-201 pigs had higher systemic and pulmonary artery pressures and had comparable cardiac outputs, but were less tachycardic. Transcutaneous tissue oxygenation was restored more rapidly in HBOC-201 pigs, there was a trend to lower lactic acid, and base deficit was less. HBOC-201 pigs had lower fluid requirements, higher urine output, and lower blood loss than HEX pigs. Conclusions: Despite evidence of va-soactivity, HBOC-201 more effectively stabilized tissue oxygenation, reversed anaerobic metabolism, decreased bleeding, and increased survival in comparison with HEX. If confirmed in clinical trials, these data suggest that for the resuscitation of combat casualties with delayed evacuation and uncontrolled HS due to solid organ injury, HBOC-201 is a superior low-volume resuscitative fluid.

Journal of Trauma: Injury, Infection & Critical Care, 2011

Background: Necrotizing soft-tissue infections (NSTIs) are associated with significant morbidity ... more Background: Necrotizing soft-tissue infections (NSTIs) are associated with significant morbidity and mortality, but a definitive nonsurgical diagnostic test remains elusive. Despite the widespread use of computed tomography (CT) as a diagnostic adjunct, there is little data that definitively correlate CT findings with the presence of NSTI. Our goal was the development of a CT-based scoring system to discriminate non-NSTI from NSTI. Methods: Patients older than 17 years undergoing CT for evaluation of soft-tissue infection at a tertiary care medical center over a 10-year period (2000-2009) were included. Abstracted data included comorbidities and social history, physical examination, laboratory findings, and operative and pathologic findings. NSTI was defined as soft-tissue necrosis in the dictated operative note or the accompanying pathology report. CT scans were reviewed by a radiologist blinded to clinical and laboratory data. A scoring system was developed and the area under the receiver operating characteristic curve was calculated. Results: During the study period, 305 patients underwent CT scanning (57% men; mean age, 47.4 years). Forty-four patients (14.4%) evaluated had an NSTI. A scoring system was retrospectively developed (table). A score Ͼ6 points was 86.3% sensitive and 91.5% specific for the diagnosis of NSTI (positive predictive value, 63.3%; negative predictive value, 85.5%). The area under the receiver operating characteristic curve was 0.928 (95% confidence interval, 0.893-0.964). The mean score of the non-NSTI group was 2.74. Conclusions: We have developed a CT scoring system that is both sensitive and specific for the diagnosis of NSTIs. This system may allow clinicians to more accurately diagnose NSTIs. Prospective validation of this scoring system is planned.

Critical Care Clinics, 2011

Airway pressure release ventilation (APRV) is an alternative mode of ventilation that is increasi... more Airway pressure release ventilation (APRV) is an alternative mode of ventilation that is increasingly used in patients with acute respiratory failure, acute lung injury (ALI), and acute respiratory distress syndrome (ARDS). Animal and clinical studies have demonstrated that, compared with conventional ventilation, APRV has beneficial effects on lung recruitment, oxygenation, end-organ blood flow, pulmonary vasoconstriction, and sedation requirements. Further studies, however, are required to directly compare APRV to ARDSnet protocol ventilation, specifically in patients with ALI/ARDS, and to determine whether managing ALI/ARDS with APRV will also achieve mortality reduction.