Association of Trauma Center Level and Patient Volume with Outcomes for Penetrating Thoracic Trauma.

BACKGROUND: We investigated the potential link between trauma center American College of Surgeons verification level and institutional volume of penetrating thoracic trauma with outcomes for patients with penetrating thoracic trauma. METHODS: Penetrating thoracic injuries were identified in the National Trauma Data Bank from 2013 to 2016. Primary exposures were trauma center American College of Surgeons verification level and annual penetrating trauma caseload by center. Cox models were used to evaluate the association between primary exposures and mortality. Poisson regression was used to evaluate admission and outcome rate differences by trauma center status. RESULTS: Of 68,727 patients identified, 38% were treated at level I centers, 18% at level II centers, and 44% at other centers. Only 3.1% required major surgery for thoracic injury (3.1% at level I, 2.6% at level II, and 3.2% at other). Overall, annual volume of penetrating thoracic trauma was not associated with mortality. For specific injuries, level I centers had superior outcomes for injuries to the thoracic aorta and vena cava compared with other centers. Level I centers also showed improved outcomes for lung/bronchus injuries compared with level II centers. Level I centers had less sepsis/acute respiratory distress syndrome, but more surgical site infection, venous thromboembolism, and unplanned operation compared with non-level I centers. CONCLUSIONS: There was no identified impact of penetrating thoracic trauma volume or trauma center verification level on overall mortality. However, level I verification did correlate with improved outcomes for some specific injuries. Further study to identify factors that improve outcomes in patients with high-risk penetrating thoracic mechanisms is warranted.

Electronic medication packaging devices and medication adherence: a systematic review.

IMPORTANCE: Medication nonadherence, which has been estimated to affect 28% to 31% of US patients with hypertension, hyperlipidemia, and diabetes, may be improved by electronic medication packaging (EMP) devices (adherence-monitoring devices incorporated into the packaging of a prescription medication). OBJECTIVES: To investigate whether EMP devices are associated with improved adherence and to identify and describe common features of EMP devices. EVIDENCE REVIEW: Systematic review of peer-reviewed studies testing the effectiveness of EMP systems in the MEDLINE, EMBASE, PsycINFO, CINAHL, International Pharmaceutical Abstracts, and Sociological Abstracts databases from searches conducted to June 13, 2014, with extraction of associations between the interventions and adherence, as well as other key findings. Each study was assessed for bias using the Cochrane Handbook for Systematic Reviews of Interventions; features of EMP devices and interventions were qualitatively assessed. FINDINGS: Thirty-seven studies (32 randomized and 5 nonrandomized) including 4326 patients met inclusion criteria (10 patient interface-only "simple" interventions and 29 "complex" interventions integrated into the health care system [2 qualified for both categories]). Overall, the effect estimates for differences in mean adherence ranged from a decrease of 2.9% to an increase of 34.0%, and the those for differences in the proportion of patients defined as adherent ranged from a decrease of 8.0% to an increase of 49.5%. We identified 5 common EMP characteristics: recorded dosing events and stored records of adherence, audiovisual reminders to cue dosing, digital displays, real-time monitoring, and feedback on adherence performance. CONCLUSIONS AND RELEVANCE: Many varieties of EMP devices exist. However, data supporting their use are limited, with variability in the quality of studies testing EMP devices. Devices integrated into the care delivery system and designed to record dosing events are most frequently associated with improved adherence, compared with other devices. Higher-quality evidence is needed to determine the effect, if any, of these low-cost interventions on medication nonadherence and to identify their most useful components.

Surgical Casualty Care in Contested Distributed Maritime Operations: Lessons Learned From the Falklands War.

The Falklands Campaign was fought a significant distance from the home base of the British Fleet. The planning and delivery of medical care during this campaign can provide significant lessons for strategic medical planning in other far spread geographic locations, including the Indo-Pacific region. Consideration of doctrine, including Role 1-4 facilities and the golden hour, may need to be reconsidered in light of changing scenarios. New concepts such as the "90-in-90" and "3-in-3" are also discussed as a framework for future planning in the U.S. Indo-Pacific Command area of responsibility.

Distributed Maritime Operations and the Medical Challenge: How a Medical Common Operating Picture Can Help Bridge the Gap.

This work explores the challenges of delivering medical care in the geographically dispersed and resource-constrained environment of Distributed Maritime Operations (DMO) and Expeditionary Advanced Base Operations (EABO). Traditional medical planning approaches may struggle to adapt to the vast operational space, extended evacuation times, and limited medical force present in these scenarios. The concept of a Medical Common Operating Picture (COP) emerges as a potential solution. By providing a shared view of the medical situation across the theater, encompassing logistics, personnel, and patient data, a medical COP has the potential to facilitate medical command and control (MED C2) in DMO/EABO. The implementation of a medical COP has the potential to optimize resource allocation, enhance situational awareness, streamline medical evacuation, and reduce healthcare provider moral injury in large-scale combat operations. A medical COP will allow medical planners to make informed decisions on triage, resupply, and evacuation, ensuring the best use of limited medical resources. This is done by leveraging a comprehensive understanding of the medical landscape, enabling informed clinical and operational decision-making by humanitarian and combat personnel respectively. A fully realized medical COP system will enable a dynamic theater evacuation policy, balancing the conflicting needs of patient care at higher echelons with the operational expediency of returning servicemembers to their operational units, thereby maximizing evacuation effectiveness. It will further enable medical personnel to perform dynamic casualty triage based on operational realities, mitigating potential ethical dilemmas. Implementing such a medical COP system will require overcoming communication limitations to facilitate data exchange and potentially integrating clinical decision support tools for real-time data analysis and recommendations. It will also require the rapid adoption of modernized operational medicine documentation solutions by medical assets within the operational forces. Ultimately, this work suggests that a medical COP has the potential to bridge the gap between traditional medical planning and the unique demands of DMO/EABO, ultimately optimizing casualty care, maximizing resource efficiency, and preserving the fighting force.

Machine Learning Differentiates Extracorporeal Membrane Oxygenation Mortality Risk Profiles Among Trauma Patients.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is resource intensive with high mortality. Identifying trauma patients most likely to derive a survival benefit remains elusive despite current ECMO guidelines. Our objective was to identify unique patient risk profiles using the largest database of trauma patients available. METHODS: ECMO patients ≥16 years were identified using Trauma Quality Improvement Program data (2010-2019). Machine learning K-median clustering (ML) utilized 101 variables including injury severity, demographics, comorbidities, and hospital stay information to generate unique patient risk profiles. Mortality and patient and center characteristics were evaluated across profiles. RESULTS: A total of 1037 patients were included with 33% overall mortality, mean age 32 years, and median ISS = 26. The ML identified 3 unique patient risk profile groups. Although mortality rates were equivalent across the 3 groups, groups were distinguished by (Group 1) young (median 25 years), severely injured (ISS = 34) patients with thoracic and head injuries (99%) via blunt mechanism (93%), and a high prevalence of ARDS (77%); (Group 2) relatively young (median 30 years) and moderately injured (ISS = 22) patients with exposure-related injuries (11%); and (Group 3) older (median 46 years) patients with a high proportion of comorbidities (69%) and extremity injuries (100%). There were no differences based on center ECMO volume, teaching status, or ACS-Level across all 3 groups. CONCLUSION: Machine learning compliments traditional analyses by identifying unique mortality risk profiles for trauma patients receiving ECMO. These details can further inform treatment guidelines, clinical decision making, and institutional criteria for ECMO usage.

Injury trends aboard US Navy vessels: A 50-year analysis of mishaps at sea.

BACKGROUND: Maritime activities have been associated with unique dangers to civilian and military sailors. We performed a retrospective cohort study analyzing injury mechanisms and clinical outcomes of casualties onboard US naval ships to determine common injury mechanisms, trends, and outcomes. We hypothesized there would be a downward trend of injuries and fatalities on US naval ships during the study period. METHODS: All mishaps recorded by the Naval Safety Command aboard active service US naval ships from 1970 through 2020 were reviewed. Only mishaps resulting in injury or fatality were included. Over time, injury mechanisms and casualty incidence rates were trended and compared based on medical capabilities. Ships without surgical capabilities were categorized as Role 1, and those with surgical capabilities as Role 2. RESULTS: There were a total of 3,127 casualties identified and analyzed, with 1,048 fatalities and 2,079 injuries. The injury mechanisms associated with the highest mortality included electrocution, blunt head trauma, fall from height, man overboard, and explosion. There was a decrease in the trend of mishaps resulting in casualties, fatalities, and injuries over the 50-year study period. The mortality rate for select severe injury mechanisms was higher on Role 1 capable platforms, compared with Role 2 (0.334 vs. 0.250, p < 0.05). CONCLUSION: Casualty incidences decreased over 50 years. However, mortality still remains high for certain mechanisms no matter the operational platform. Furthermore, Role 1 capable vessels have a higher overall mortality rate for severe injuries compared with Role 2. The authors propose training, process improvement, and technology-related solutions to improve outcomes on Role 1 capable naval vessels. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Pediatric penetrating thoracic trauma: Examining the impact of trauma center designation and penetrating trauma volume on outcomes.

INTRODUCTION: We analyzed the impact of treating center designation and case volume of penetrating trauma on outcomes after pediatric penetrating thoracic injuries (PTI). METHODS: PTI patients <18 years were identified from the National Trauma Data Bank (2013-2016). Centers were categorized by type (Pediatric or Adult) and designation status (Level I, Level II, and other). Performance was calculated as the difference between observed and expected mortality and standardized using the total penetrating trauma volume per center. Expected mortality was calculated using the Trauma Mortality Prediction Model. Pearson correlation and linear mixed-effects models evaluated the association between variables and performance. RESULTS: We identified 4,134 PTI patients treated at 596 trauma centers: 879 (21%) at Adult Level I, 608 (15%) at Adult Level II, 531 (13%) at Pediatric Level I, 320 (8%) at Pediatric Level II, and 1,796 (43%) at other centers. Primary injury mechanisms were firearm-related (58%) and cut/piercing (42%). Overall mortality was 16% and median predicted mortality was 3.6% (IQR: 1.5% - 11.2%). Among patients with thoracic firearm-related injuries, centers with lower penetrating case volume and total trauma care demonstrated significantly worse outcomes. Multivariable analysis revealed Adult Level I centers had superior outcomes compared with all other non-Level I centers. There was no difference in mortality between Pediatric and Adult Level I centers. DISCUSSION: Adult Level I trauma center designation and annual case volume of penetrating thoracic trauma are associated with improved mortality after pediatric firearm-related thoracic injuries. Further study is needed to identify factors in higher volume centers that improve outcomes. LEVEL OF EVIDENCE: Level III.

Extracytoplasmic stress responses induced by antimicrobial cationic polyethylenimines.

The ability of an antimicrobial, cationic polyethylenimine (PEI+) to induce the three known extracytoplasmic stress responses of Escherichia coli was quantified. Exposure of E. coli to PEI+ in solution revealed specific, concentration-dependent induction of the Cpx extracytoplasmic cellular stress response, ~2.0-2.5-fold at 320 µg/mL after 1.5 h without significant induction of the σ(E) or Bae stress responses. In comparison, exposure of E. coli to a non-antimicrobial polymer, poly(ethylene oxide) (PEO), resulted in no induction of the three stress responses. The antimicrobial small molecule vanillin, a known membrane pore-forming compound, was observed to cause specific, concentration-dependent induction of the σ(E) stress response, ~6-fold at 640 µg/mL after 1.5 h, without significant induction of the Cpx or Bae stress responses. The different stress response induction profiles of PEI+ and vanillin suggest that although both are antimicrobial compounds, they interact with the bacterial membrane and extracytoplasmic area by unique mechanisms. EPR studies of liposomes containing spin-labeled lipids exposed to PEI+, vanillin, and PEO reveal that PEI+ and PEO increased membrane stability, whereas vanillin was found to have no effect.

Renal Function at Discharge Among Kidney Recipients Experiencing Delayed Graft Function and Its Associations With Long-term Outcomes.

Delayed graft function (DGF) after kidney transplantation is associated with higher rates of acute rejection and poor graft survival and outcomes. Current DGF definitions based on posttransplant need for dialysis are not standardized and there are no objective methodologies for quantifying DGF severity. Methods: Using Organ Procurement and Transplantation Network data, we examined DGF, and used recipient serum creatinine at discharge as a correlate of renal function and DGF severity (mild: <2.5 mg/dL; severe: ≥2.5 mg/dL). The associations between donor and recipient factors and DGF severity were quantified using logistic regression. We also examined the associations between DGF severity and long-term recipient outcomes, adjusting for potential confounders. Results: A predictive model using donor and recipient factors had a reasonably good ability to discriminate mild (low creatinine) versus severe (high creatinine) DGF (c-statistic of 0.70). In Cox regression, DGF and creatinine at discharge were both independently associated with long-term outcomes, yet their effects differed depending on the outcome (graft function, death-censored graft function, recipient mortality). Our findings suggest that having DGF, but with relatively good renal function (creatinine <2.5) at discharge, may be less deleterious on graft and recipient survival compared with severe, prolonged DGF, which was associated with a decreased median graft survival of ~2.6 y compared with no DGF with low creatinine at discharge. Conclusions: Our novel DGF severity stratification identified unique factors associated with DGF severity, along with DGF's association with long-term graft and patient survival. The adverse cost and outcome implications of severe DGF warrant additional investigation to improve kidney transplantation practice.

Financial Vulnerability of American College of Surgeons-Verified Trauma Centers: A Statewide Analysis.

BACKGROUND: Although trauma centers represent an integral part of healthcare in the US, characterization of their financial vulnerability has not been reported. We sought to characterize the financial health and vulnerability among California trauma centers and identify factors associated with high and low vulnerability. STUDY DESIGN: The RAND Hospital Data financial dataset was used to evaluate all American College of Surgeons (ACS)-verified trauma centers in California. Financial vulnerability of each center was calculated using 6 metrics to calculate a composite Financial Vulnerability Score (FVS). Tertiles of the FVS were generated to classify trauma centers as high, medium, or low financial vulnerability. Hospital characteristics were also analyzed and compared. RESULTS: Forty-seven ACS trauma centers were identified. Nine were Level I, 27 were Level II, and 8 were Level III. Level I centers encompassed the greatest proportion of the high FVS tier (44%), whereas Level II and III centers were the most likely to be in the middle and lower tiers, respectively (44%; 63%). Lower FVS centers had greater asset:liability ratios, operating margins, and days cash on hand compared with the 2 higher tiers, whereas high FVS centers showed a greater proportion of uncompensated care, outpatient share rates, outpatient surgeries, and longer days in net accounts. Lower FVS centers were more likely to be teaching hospitals and members of a larger corporate entity. CONCLUSION: Many ACS trauma centers are at moderate/high risk for financial vulnerability and disparate impacts of stressor events, and the FVS may represent a novel metric that could be used at the local or statewide level.

Why Trauma Care is Not Expensive: Detailed Analysis of Actual Costs and Cost Differences of Patient Cohorts.

BACKGROUND: Trauma patients are resource intensive, requiring a variety of medical and procedural interventions during hospitalization. These expenses often label trauma care as "high cost" based on gross hospital charges. We hypothesized that a financial metric built on actual costs and clinically relevant trauma patient cohorts would demonstrate a lower true cost of trauma care than the standardly reported gross hospital charges. METHODS: We examined all trauma patients (≥16 yr) treated in 2017 from a single institution and matched them to the institution's detailed financial accounting data. The organization's Financial Operations Division is uniquely able to allocate total operating costs across patient encounters to include medications, procedures, and salaries/fees from medical professionals and administrators. Patient subgroups were identified by Trauma Quality Improvement Program (TQIP) criteria for cost comparisons. RESULTS: Overall median cost per patient was $6,544 [IQR $4,975-14,532] for 2,548 patients. The median cost per patient increased with Injury Severity Score (ISS) ranging from $5,457(ISS ≤ 7) to $34,898(ISS ≥ 21), each accompanied by an average 548% increase in gross charges. Costs also varied widely from $13,498 [IQR $8,247-26,254] to $45,759 [IQR $22,186-113,993] across TQIP patient cohorts. Of the total cost, 91% was attributed to personnel alone. DISCUSSION: Measuring the true cost of trauma care is feasible. As hypothesized, the true cost of trauma care is lower than charges. True cost increased with injury severity with variable cost across subgroups. Non-physician staff and administration are the largest component of the cost of trauma care.

A tale of two centers: Is low-molecular-weight heparin really superior for prevention of posttraumatic venous thromboembolism?

BACKGROUND: Low-molecular-weight heparin (LMWH) is widely used for venous thromboembolism chemoprophylaxis following injury. However, unfractionated heparin (UFH) is a less expensive option. We compared LMWH and UFH for prevention of posttraumatic deep venous thrombosis (DVT) and pulmonary embolism (PE). METHODS: Trauma patients 15 years or older with at least one administration of venous thromboembolism chemoprophylaxis at two level I trauma centers with similar DVT-screening protocols were identified. Center 1 administered UFH every 8 hours for chemoprophylaxis, and center 2 used twice-daily antifactor Xa-adjusted LMWH. Clinical characteristics and primary chemoprophylaxis agent were evaluated in a two-level logistic regression model. Primary outcome was incidence of DVT and PE. RESULTS: There were 3,654 patients: 1,155 at center 1 and 2,499 at center 2. The unadjusted DVT rate at center 1 was lower than at center 2 (3.5% vs. 5.0%; p = 0.04); PE rates did not significantly differ (0.4% vs. 0.6%; p = 0.64). Patients at center 2 were older (mean, 50.3 vs. 47.3 years; p < 0.001) and had higher Injury Severity Scores (median, 10 vs. 9; p < 0.001), longer stays in the hospital (mean, 9.4 vs. 7.0 days; p < 0.001) and intensive care unit (mean, 3.0 vs. 1.3 days; p < 0.001), and a higher mortality rate (1.6% vs. 0.6%, p = 0.02) than patients at center 1. Center 1's patients received their first dose of chemoprophylaxis earlier than patients at center 2 (median, 1.0 vs. 1.7 days; p < 0.001). After risk adjustment and accounting for center effects, primary chemoprophylaxis agent was not associated with risk of DVT (odds ratio, 1.01; 95% confidence interval, 0.69-1.48; p = 0.949). Cost calculations showed that UFH was less expensive than LMWH. CONCLUSION: Primary utilization of UFH is not inferior to LMWH for posttraumatic DVT chemoprophylaxis and rates of PE are similar. Given that UFH is lower in cost, the choice of this chemoprophylaxis agent may have major economic implications. LEVEL OF EVIDENCE: Prognostic and epidemiological, level II; Therapeutic, level III.

Pediatric extremity vascular trauma: It matters where it is treated.

BACKGROUND: Extremity vascular injuries in children are rare events that present unique therapeutic challenges. The absence of a pediatric-specific protocol for definitive care of these injuries risks variability in treatment practices and outcomes. Using a nationwide data set, we investigated variations in the management and outcomes of pediatric patients with peripheral vascular trauma and characterized differences based on hospital category. METHODS: Retrospective cohort study using the American College of Surgeons (ACS) National Trauma Data Bank to identify patients 16 years or younger with extremity vascular trauma admitted in calendar year 2016. Hospitals were categorized as ACS-verified pediatric trauma centers (Level I or II), ACS-verified adult trauma centers (Level I or II), or other hospitals (all other trauma centers and nondesignated hospitals). Patient data were evaluated by hospital category. RESULTS: Among 164,882 pediatric admissions, 702 patients were identified for analysis. There were 430 (61.3%) patients with upper-extremity injuries, 270 (38.5%) with lower-extremity injuries, and 2 (0.2%) had both. Mean age was 11.5 years, and 51.6% were blunt-injured. Overall, 40.2% were admitted to pediatric trauma centers, 28.9% to adult trauma centers, and 30.9% to other hospitals. Hospitals without ACS trauma center verification had a significantly higher amputation rate than any ACS-verified adult or pediatric center (p = 0.013). CONCLUSION: The incidence of pediatric extremity vascular injury is low. Hospitals with ACS trauma center verification have greater pediatric limb salvage rates than those without verification. Future study should seek to identify specific regional or resource-related factors that contribute to this disparity. LEVEL OF EVIDENCE: Epidemiological, level III.

Trephination versus wide excision for the treatment of pediatric pilonidal disease.

BACKGROUND/PURPOSE: To evaluate outcomes of trephination compared to wide excision in children undergoing initial surgical treatment of pilonidal disease. METHODS: A retrospective review was conducted of patients undergoing initial pilonidal excision between September 2017 and September 2018. Operations were categorized as either trephination or wide excision via an open or closed-wound technique. Outcomes were evaluated and data analyzed by chi-squared and one-way ANOVA tests. RESULTS: One-hundred and five patients were identified, with a mean follow-up of 4.6 months. Trephination was performed in 57% of patients, and of the remaining patients undergoing wide excision, 62% of wounds were left open. There were no demographic differences among the three groups. Compared to both the open and closed techniques, trephination was associated with fewer wound complications (17% vs 29% vs 3%, respectively, p = 0.006), and postoperative visits (4.4 vs 2.4 vs 1.4, respectively, p < 0.001). There was no difference in recurrence rates among groups. CONCLUSION: Trephination for pilonidal disease in pediatric patients is associated with a lower wound complication rate and fewer postoperative visits compared to wide excision. Recurrence rates are similar among the various surgical methods. Further prospective study would be useful to describe long-term outcomes of patients undergoing trephination for pilonidal disease. TYPE OF STUDY: Treatment study. LEVEL OF EVIDENCE: III (retrospective comparative).

Evaluating surgical outcomes in pediatric extremity vascular trauma.

BACKGROUND: The purpose of this study was to evaluate the epidemiology and management of pediatric vascular extremity trauma to assess injury patterns and other factors that may contribute to poor outcomes. METHODS: Using the California Office of Statewide Health Planning and Development discharge database, we identified pediatric patients with extremity arterial trauma admitted to acute-care hospitals from 2007 to 2014. Demographics, management patterns, and outcomes were collected and analyzed. RESULTS: A total of 775 patients were treated for an extremity arterial injury. Overall, 40% were admitted to pediatric trauma centers and 39% to adult trauma centers. Management was predominantly by open surgical repair. Injury to the common femoral artery was associated with mortality (Hazard Ratio 3.9; 95% CI 1.1-14.5; p < 0.05). Popliteal artery injuries (Odds Ratio [OR] 4.8; 95% CI 1.2-19.9; p < 0.05) and anterior tibial artery injuries (OR 7.1; 95% CI 1.4-37.3; p < 0.05) had an increased risk of amputation. There was no difference in amputation or mortality rates by hospital category. CONCLUSIONS: Pediatric extremity arterial injuries are rare. In California, outcomes are similar by hospital type. Common femoral artery injuries are associated with an increased risk of mortality, while popliteal and anterior tibial artery injuries are associated with an increased risk of amputation. TYPE OF STUDY: Prognosis Study. LEVEL OF EVIDENCE: Level III.

The e-merging e-pidemic of e-scooters.

INTRODUCTION: Since their release in 2017, standing electric motorized scooters (eScooters) have risen in popularity as an alternative mode of transportation. We sought to examine the incidence of injury, injury patterns, prevalence of helmet and drug and alcohol use in eScooter trauma. METHODS: This was a multi-institutional retrospective case series of patients admitted for injuries related to operation of an eScooter following the widespread release of these devices in September 2017 (September 1, 2017 to October 31, 2018). Demographics, drug and alcohol use, helmet use, admission vitals, injuries, procedures, hospital and intensive care unit length of stay (LOS), death, and disposition were analyzed. RESULTS: 103 patients were admitted during the study period, and monthly admissions increased significantly over time. Patients were young men (mean age 37.1 years; 65% male), 98% were not wearing a helmet. Median LOS was 1 day (IQR 1-3). 79% of patients were tested for alcohol and 48% had a blood alcohol level >80 mg/dL. 60% of patients had a urine toxicology screen, of which 52% were positive. Extremity fractures were the most frequent injury (42%), followed by facial fractures (26%) and intracranial hemorrhage (18%). Median Injury Severity Score was 5.5 (IQR 5-9). One-third of patients (n=34) required an operative intervention, the majority of which were open fixations of extremity and facial fractures. No patients died during the study. The majority of patients were discharged home (86%). CONCLUSION: eScooter-related trauma has significantly increased over time. Alcohol and illicit substance use among these patients was common, and helmet use was extremely rare. Significant injuries including intracranial hemorrhage and fractures requiring operative intervention were present in over half (51%) of patients. Interventions aimed at increasing helmet use and discouraging eScooter operation while intoxicated are necessary to reduce the burden of eScooter-related trauma. LEVEL OF EVIDENCE: Level IV.

Preparation of single cells for imaging/profiling mass spectrometry.

Characterizing chemical changes within individual cells is important for determining fundamental mechanisms of biological processes that will lead to new biological insights and improved disease understanding. Analyzing biological systems with imaging and profiling mass spectrometry (MS) has gained popularity in recent years as a method for creating chemical maps of biological samples. To obtain mass spectra that provide relevant molecular information about individual cells, samples must be prepared so that salts and other cell culture components are removed from the cell surface and that the cell contents are rendered accessible to the desorption beam. We have designed a cellular preparation protocol for imaging/profiling MS that removes the majority of the interfering species derived from the cellular growth medium, preserves the basic morphology of the cells, and allows chemical profiling of the diffusible elements of the cytosol. Using this method, we are able to reproducibly analyze cells from three diverse cell types: MCF7 human breast cancer cells, Madin-Darby canine kidney (MDCK) cells, and NIH/3T3 mouse fibroblasts. This preparation technique makes possible routine imaging/profiling MS analysis of individual cultured cells, allowing for understanding of molecular processes within individual cells.