Indications and Outcomes for Adult Extracorporeal Membrane Oxygenation at a Military Referral Facility

INTRODUCTION

Extracorporeal life support, including extracorporeal membrane oxygenation (ECMO), is a potentially life-saving adjunct to therapy in patients experiencing pulmonary and/or cardiac failure. The U.S. DoD has only one ECMO center, in San Antonio, Texas. In this study, we aimed to analyze outcomes at this center in order to determine whether they are on par with those reported elsewhere in the literature.

MATERIALS AND METHODS

In this observational study, we analyzed data from patients treated with ECMO at the only DoD ECMO center between September 2012 and April 2020. The primary outcome was survival to discharge, and secondary outcomes were discharge disposition and incidence of complications.

RESULTS

One hundred and forty-three patients were studied, with a 70.6% rate of survival to discharge. Of the patients who survived, 32.7% were discharged home; 32.7% were discharged to a rehabilitation facility; and 33.7% were transferred to another hospital, 29.4% of whom were transferred to lung transplant centers. One patient left against medical advice. Incidence of ECMO-related complications were as follows: 64 patients (44.7%) experienced hemorrhagic complications, 80 (55.9%) had renal complications, 61 (42.6%) experienced cardiac complications, 39 (27.3%) had pulmonary complications, and 5 patients (3.5%) experienced limb ischemia. We found that these outcomes were comparable to those reported in the literature.

CONCLUSIONS

Extracorporeal membrane oxygenation can be an efficacious adjunct in management of critically ill patients who require pulmonary and/or cardiac support. This single-center observational study demonstrated that the DoD's only ECMO center has outcomes comparable with the reported data in Extracorporeal Life Support Organization's registry.

Impact of Rank, Provider Specialty, and Unit Sustainment Training Frequency on Military Critical Care Air Transport Team Readiness

BACKGROUND

The Critical Care Air Transport (CCAT) Advanced Course utilizes fully immersive high-fidelity simulations to assess personnel readiness for deployment. This study aims to determine whether simple well-defined demographic identifiers can be used to predict CCAT students' performance at CCAT Advanced.

MATERIALS AND METHODS

CCAT Advanced student survey data and course status (pass/fail) between March 2006 and April 2020 were analyzed. The data included students' Air Force Specialty Code (AFSC), military status (active duty and reserve/guard), CCAT deployment experience (yes/no), prior CCAT Advanced training (yes/no), medical specialty, rank, and unit sustainment training frequency (never, frequency less often than monthly, and frequency at least monthly). Following descriptive analysis and comparative tests, multivariable regression was used to identify the predictors of passing the CCAT Advanced course for each provider type.

RESULTS

A total of 2,576 student surveys were analyzed: 694 (27%) physicians (MDs), 1,051 (40%) registered nurses (RNs), and 842 (33%) respiratory therapists (RTs). The overall passing rates were 92.2%, 90.3%, and 85.4% for the MDs, RNs, and RTs, respectively. The students were composed of 579 (22.5%) reserve/guard personnel, 636 (24.7%) with CCAT deployment experience, and 616 (23.9%) with prior CCAT Advanced training. Regression analysis identified groups with lower odds of passing; these included (1) RNs who promoted from Captain to Major (post-hoc analysis, P = .03), (2) RTs with rank Senior Airman, as compared to Master Sergeants (post-hoc analysis, P = .04), and (3) MDs with a nontraditional AFSC (P = .0004). Predictors of passing included MDs and RNs with CCAT deployment experience, odds ratio 2.97 (P = .02) and 2.65 (P = .002), respectively; and RTs who engaged in unit CCAT sustainment at least monthly (P = .02). The identifiers prior CCAT Advanced training or reserve/guard military status did not confer a passing advantage.

CONCLUSION

Our main result is that simple readily available metrics available to unit commanders can identify those members at risk for poor performance at CCAT Advanced readiness training; these include RNs with rank Major or above, RTs with rank Senior Airman, and RTs who engage in unit sustainment training less often than monthly. Finally, MD specialties which are nontraditional for CCAT have significantly lower CCAT Advanced passing rates, reserve/guard students did not outperform active duty students, there was no difference in the performance between different RN specialties, and for MD and RN students' previous deployment experience was a strong predictor of passing.

Warfarin, not direct oral anticoagulants nor antiplatelet therapy, is associated with increased bleeding risk in emergency general surgery patients: implications in this new era of novel anticoagulants: An EAST Multicenter study

INTRODUCTION

To assess perioperative bleeding complications & in-hospital mortality in patients requiring emergency general surgery (EGS) presenting with a history of antiplatelet (AP) vs. direct oral anticoagulant (DOAC) vs warfarin use.

METHODS

Prospective observational study across 21 centers between 2019-2022. Inclusion criteria were age ≥ 18 years, & DOAC, warfarin or AP use within 24 hours of an EGSP. Outcomes included perioperative bleeding and in-hospital mortality. The study was conducted using ANOVA, Chi-square, and multivariable regression models.

RESULTS

Of the 413 patients, 221 (53.5%) reported AP use, 152 (36.8%) DOAC use, & 40 (9.7%) warfarin use. Most common indications for surgery were obstruction (23% (AP), 45% (DOAC), 28% (warfarin)), intestinal ischemia (13%, 17%, 23%), & diverticulitis/peptic ulcers (7%, 7%, 15%). Compared to DOAC use, warfarin use was associated with significantly higher perioperative bleeding complication (OR 4.4 [2.0, 9.9]). There was no significant difference in perioperative bleeding complication between DOAC & AP use (OR 0.7 [0.4, 1.1]). Compared to DOAC use, there was no significant difference in mortality between warfarin use (0.7 [0.2, 2.5]) or AP use (OR 0.5 [0.2, 1.2]). After adjusting for confounders, warfarin use (OR 6.3 [2.8, 13.9]), medical history and operative indication were associated with an increase in perioperative bleeding complications. However, warfarin was not independently associated with risk of mortality (OR 1.3 [0.39, 4.7]), whereas intraoperative vasopressor use (OR 4.7 [1.7, 12.8)), medical history & postoperative bleeding (OR 5.5 [2.4, 12.8]) were.

CONCLUSIONS

Despite ongoing concerns about the increase in DOAC use & lack of readily available reversal agents, this study suggests that warfarin, rather than DOACs, is associated with higher perioperative bleeding complications. However, that risk does not result in an increase in mortality, suggesting that perioperative decisions should be dictated by patient disease & comorbidities rather than type of antiplatelet or anticoagulant use.

The Military-Civilian Partnership Quality Improvement Program Concept: A Process to Improve Data Collection and Outcomes Assessment

INTRODUCTION

Military-Civilian Partnerships (MCPs) are vital for maintaining the deployment readiness of military health care physicians. However, tracking their clinical activity has proven to be challenging. In this study, we introduce a locally driven process aimed at the passive collection of external clinical workload data. This process is designed to facilitate an assessment of MCP physicians' deployment readiness and the effectiveness of individual MCPs.

MATERIALS AND METHODS

From March 2020 to February 2023, we conducted a series of quality improvement projects at the Wright Patterson Medical Center (WPMC) to enhance our data collection efforts for MCP physicians. Our methodology encompassed several steps. First, we assessed our existing data collection processes and their outcomes to identify improvement areas. Next, we tested various data collection methods, including self-reporting, a web-based smart phone application, and an automated process based on billing or electronic health record data. Following this, we refined our data collection process, incorporating the identified improvements and systematically tracking outcomes. Finally, we evaluated the refined process in 2 different MCPs, with our primary outcome measure being the collection of monthly health care data.

RESULTS

Our examination at the WPMC initially identified several weaknesses in our established data collection efforts. These included unclear responsibility for data collection within the Medical Group, an inadequate roster of participating MCP physicians, and underutilization of military and community resources for data collection. To address these issues, we implemented revisions to our data collection process. These revisions included establishing clear responsibility for data collection through the Office of Military-Civilian Partnerships, introducing a regular "roll call" to match physicians to MCP agreements, passively collecting data each month through civilian partner billing or information technology offices, and integrating Office of Military-Civilian Partnership efforts into regular executive committee meetings. As a result, we observed a 4-fold increase in monthly data capture at WPMC, with similar gains when the refined process was implemented at an Air Force Center for the Sustainment of Trauma and Readiness Skills site.

CONCLUSIONS

The Military-Civilian Partnership Quality Improvement Program concept is an effective, locally driven process for enhancing the capture of external clinical workload data for military providers engaged in MCPs. Further examination of the Military-Civilian Partnership Quality Improvement Program process is needed at other institutions to validate its effectiveness and build a community of MCP champions.

Anticoagulation in emergency general surgery: Who bleeds more? The EAST multicenter trials ACES study

BACKGROUND

While direct oral anticoagulant (DOAC) use is increasing in the Emergency General Surgery (EGS) patient population, our understanding of their bleeding risk in the acute setting remains limited. Therefore, the objective of this study was to determine the prevalence of perioperative bleeding complications in patients using DOACs versus warfarin and AP therapy requiring urgent/emergent EGS procedures (EGSPs).

METHODS

This was a prospective observational trial, conducted between 2019 and 2022, across 21 centers. Inclusion criteria were 18 years or older, DOAC, warfarin/AP use within 24 hours of requiring an urgent/emergent EGSP. Demographics, preoperative, intraoperative, and postoperative data were collected. ANOVA, χ 2 , and multivariable regression models were used to conduct the analysis.

RESULTS

Of the 413 patients enrolled in the study, 261 (63%) reported warfarin/AP use and 152 (37%) reported DOAC use. Appendicitis and cholecystitis were the most frequent indication for operative intervention in the warfarin/AP group (43.4% vs. 25%, p = 0.001). Small bowel obstruction/abdominal wall hernias were the main indication for operative intervention in the DOAC group (44.7% vs. 23.8%, p = 0.001). Intraoperative, postoperative, and perioperative bleeding complications and in-hospital mortality were similar between the two groups. After adjusting for confounders, a history of chemotherapy (odds ratio [OR], 4.3; p = 0.015) and indication for operative intervention including occlusive mesenteric ischemia (OR, 4.27; p = 0.016), nonocclusive mesenteric ischemia (OR, 3.13; p = 0.001), and diverticulitis (OR, 3.72; p = 0.019) were associated with increased perioperative bleeding complications. The need for an intraoperative transfusion (OR, 4.87; p < 0.001), and intraoperative vasopressors (OR, 4.35; p = 0.003) were associated with increased in-hospital mortality.

CONCLUSION

Perioperative bleeding complications and mortality are impacted by the indication for EGSPs and patient's severity of illness rather than a history of DOAC or warfarin/AP use. Therefore, perioperative management should be guided by patient physiology and indication for surgery rather than the concern for recent antiplatelet or anticoagulant use.

LEVEL OF EVIDENCE

Prognostic and Epidemiologic; Level III.

The Ability of Military Critical Care Air Transport Members to Visually Estimate Percent Systolic Pressure Variation

INTRODUCTION

Inappropriate fluid management during patient transport may lead to casualty morbidity. Percent systolic pressure variation (%SPV) is one of several technologies that perform a dynamic assessment of fluid responsiveness (FT-DYN). Trained anesthesia providers can visually estimate and use %SPV to limit the incidence of erroneous volume management decisions to 1-4%. However, the accuracy of visually estimated %SPV by other specialties is unknown. The aim of this article is to determine the accuracy of estimated %SPV and the incidence of erroneous volume management decisions for Critical Care Air Transport (CCAT) team members before and after training to visually estimate and utilize %SPV.

MATERIAL AND METHODS

In one sitting, CCAT team providers received didactics defining %SPV and indicators of fluid responsiveness and treatment with %SPV ≤7 and ≥14.5 defining a fluid nonresponsive and responsive patient, respectively; they were then shown ten 45-second training arterial waveforms on a simulated Propaq M portable monitor's screen. Study subjects were asked to visually estimate %SPV for each arterial waveform and queried whether they would treat with a fluid bolus. After each training simulation, they were told the true %SPV. Seven days post-training, the subjects were shown a different set of ten 45-second testing simulations and asked to estimate %SPV and choose to treat, or not. Nonparametric limits of agreement for differences between true and estimated %SPV were analyzed using Bland-Altman graphs. In addition, three errors were defined: (1) %SPV visual estimate errors that would label a volume responsive patient as nonresponsive, or vice versa; (2) incorrect treatment decisions based on estimated %SPV (algorithm application errors); and (3) incorrect treatment decisions based on true %SPV (clinically significant treatment errors). For the training and testing simulations, these error rates were compared between, and within, provider groups.

RESULTS

Sixty-one physicians (MDs), 64 registered nurses (RNs), and 53 respiratory technicians (RTs) participated in the study. For testing simulations, the incidence and 95% CI for %SPV estimate errors with sufficient magnitude to result in a treatment error were 1.4% (0.5%, 3.2%), 1.6% (0.6%, 3.4%), and 4.1% (2.2%, 6.9%) for MDs, RNs, and RTs, respectively. However, clinically significant treatment errors were statistically more common for all provider types, occurring at a rate of 7%, 10%, and 23% (all P < .05). Finally, students did not show clinically relevant reductions in their errors between training and testing simulations.

CONCLUSIONS

Although most practitioners correctly visually estimated %SPV and all students completed the training in interpreting and applying %SPV, all groups persisted in making clinically significant treatment errors with moderate to high frequency. This suggests that the treatment errors were more often driven by misapplying FT-DYN algorithms rather than by inaccurate visual estimation of %SPV. Furthermore, these errors were not responsive to training, suggesting that a decision-making cognitive aid may improve CCAT teams' ability to apply FT-DYN technologies.

2012. A Descriptive Study of Infections Complicating Extracorporeal Membrane Oxygenations in Trauma Patients

Background

Extracorporeal Membrane Oxygenation (ECMO) is a growing modality for respiratory and circulatory support in patients with traumatic injuries. There is limited data on the pathogens complicating a trauma patient’s ECMO course and thus empiric antibiotic choices are difficult in this cohort. We report the incidence and infection type in trauma patients receiving ECMO to potentially guide future empiric antibiotic treatment and improve outcomes.

Methods

A descriptive chart review was performed on all trauma patients at Brooke Army Medical Center receiving ECMO between February 2013 and July 2021. Charts were reviewed to identify pathogens by culture site as well as time to infection following cannulation. This protocol was approved by the 59th Medical Wing Institutional Review Board.

Results

Twenty-one trauma patients underwent ECMO during the study period. The majority of patients were men (n=19, 90%) with a median age of 30 years [IQR 27-38] with a median ECMO run of 227 hours [IQR 93-338]. Motor vehicle crashes (17, 81%) accounted for the majority of injuries, with gunshot wounds (2, 10%), blast injuries (1, 5%) and falls (1, 5%) accounting for the remainder. 16 (76%) patients survived to discharge, and infection was not associated with mortality (p=0.11). Of the 24 infections, the majority were respiratory (13, 58/1000 ECMO days) followed by skin and soft tissue (6, 26/1000 ECMO days), blood stream (4, 18/1000 ECMO days), and urinary tract (1, 5/1000 ECMO days). Gram-negatives were the most commonly isolated organism from all sites (Table 1) and at all time periods after cannulation (Table 2). Multi-drug resistant organisms accounted for 32% (n=9) of infections and were independent of time from cannulation.

Conclusion

This is the first study to describe infections in trauma patients requiring ECMO support. We observed majority Gram-negative infections regardless of culture site or time after cannulation. Determining empiric antibiotics will require a larger study of patients to identify trends in pathogens and ultimately improve antimicrobial stewardship in this unique population.

Disclosures

All Authors: No reported disclosures.

Implementation of a Traumatic Brain Injury Guideline at A Dod Level 1 Trauma Center

BACKGROUND

Traumatic brain injury (TBI) is one of the most prevalent diagnoses among trauma populations and places significant strain on valuable rural hospital resources. Limited studies show safety and efficacy of implementation of a Brain Injury Guideline (BIG) protocol at a Department of Defense (DoD) Level 1 trauma center.

MATERIALS AND METHODS

Data from patients diagnosed with traumatic brain injury during the study period were collected from our institutional trauma database. A retrospective review was performed on patients identified in the database to collect demographic and injury related data. All primary and secondary outcome data were analyzed using two-tailed Fischer's exact tests, Pearson Chi-square tests, and non-parametric Mann Whitney U tests.

RESULTS

A total of 354 patients were included in the study, 189 pre-implementation and 165 post-implementation. Demographics, head injury severity, initial HCT findings, and BIG classification distributions were well-matched. There was a significant reduction in neurosurgical consultations (NSC) (98.4% pre- to 77.0% post-implementation, P<0.001) and ICU admissions (84.1% pre-, 74.5% post-implementation, P=0.025) following protocol implementation. There were no differences between groups in ICU LOS (P=0.239), incidence of worsening findings on RHCT (P=0.894), or in-hospital mortality (P=0.814). There was a slight reduction in hospital LOS from 4.0d pre-implementation to 3.0d post-implementation (P=0.043).

CONCLUSIONS

Implementation of a BIG protocol at our Level 1 trauma center suggested at a relationship with fewer NSCs and ICU admissions. Management of mild and moderate TBI by acute care and trauma surgeons without direct neurosurgical oversight is safe and implies a reduction in utilization of hospital resources.

80. The Utility of Cultures for Isolated Fevers in Patients with Influenza or COVID-19 Receiving Extracorporeal Membrane Oxygenation

Background

Critically ill patients receiving extracorporeal membrane oxygenation (ECMO) are at elevated risk for nosocomial infection. Physiological responses to infection on ECMO are difficult to interpret as many clinical characteristics are controlled by the circuit including temperature. This study aimed to determine the culture positivity rates in patients receiving ECMO with influenza or COVID-19.

Methods

A single center retrospective study was performed on all patients who received ECMO support at a single institution between December 2014 and December 2020 with influenza or COVID-19. All cultures ordered were reviewed for indication. Patients with fever without specific clinical syndrome or signs of decompensation, such as increasing vasopressor requirement were included. Infections and contaminants were defined by treatment team.

Results

A total of 45 patients received ECMO with an admission diagnosis of influenza or COVID-19 during the study period. This cohort had a median age of 44 (interquartile range (IQR): 36-53) and was predominantly male (84%). The median time on ECMO was 360 hours (IQR: 183-666). 43/137 (31%) of infectious workups were ordered for isolated fever. The most common workup ordered for fever was combination blood cultures (BC) and urine cultures (UC) (13, 30%), followed by combination BC, UC, and respiratory cultures (RC) (11, 26%). Four (9%) infections were identified (3 blood stream, 1 respiratory) and five (12%) cultures grew contaminants (1 blood, 1 respiratory, 2 urine). Culture positivity rate was greatest for BC (3/35, 9%) followed by RC (1/19, 5%), and lowest for UC (0/26, 0%).

Conclusion

Although cultures are commonly ordered for isolated fever in patients with influenza and COVID-19 receiving ECMO, culture positivity rate is low. In particular, no urinary tract infections were identified and the screening for urinary tract infection in patients receiving ECMO with isolated fever is not beneficial. Further work identifying signs and symptoms associated with infection is needed to improve diagnostic stewardship in this population that is high risk for nosocomial infections.

Disclosures

All Authors: No reported disclosures

807. Effect of Inter-Hospital Transfer on Nosocomial Infection Rates in Patients Receiving Extracorporeal Membrane Oxygenation

Background

Extracorporeal Oxygenation (ECMO) has been increasingly used as a life support modality for cardiac and pulmonary failure. Due to improved survival in patients treated in high volume ECMO centers, inter-hospital transport of these critically ill patients is on the rise. These patients may be transported via ambulance locally, or by aircraft over long distances. However, potential risks of nosocomial infectious complications associated with transfers has not been reported. We evaluated the impact of transfers on nosocomial infections for patients who received ECMO at Brooke Army Medical Center (BAMC).

Methods

All patients who received ECMO for ≥48 hours at BAMC between May 2012 and October 2019 were included. Chart review was performed to determine transport status, infectious complications while on ECMO, and antimicrobial susceptibility of isolated organisms. Statistical analyses were performed using Chi-squared, Fisher’s exact, or Mann-Whitney U tests as appropriate. Factors associated with nosocomial infections were evaluated by multivariate logistic regression.

Results

Compared to patients who were cannulated locally (n=33), patients who underwent cannulation at referral facility and inter-hospital transfer (n=76) had no difference in infections per 1000 ECMO days (33.1 vs. 30.5, p=0.74) or in infections with multidrug resistant organisms (MDRO) (50% vs. 55%, p=1). Of transferred patients, those transferred by aircraft (n=11) had no difference in infection rate (22.4 vs. 31.8 per 1000 ECMO days, p= 0.39) or MDRO incidence (52% vs 75%, p=0.61) compared to those only transferred by ambulance (n=65). Multivariate analysis showed the greatest risk factor for nosocomial infection was time on ECMO (OR 12.2 for longest tertile time on ECMO vs. shortest tertile, p=0.0001); transport was not significantly associated with infection (OR 2.1, p=0.06).

Nosocomial infection rate by site of ECMO cannulation

Conclusion

This study did not find a significant difference in nosocomial infection rate or recovery of MDROs between transported and non-transported patients on ECMO, regardless of transport modality. This study suggests that transportation is not the primary driver of nosocomial infections in this cohort.

Disclosures

All Authors: No reported disclosures

2095. Infections in Burn Patients Receiving Extracorporeal Membrane Oxygenation (ECMO) at a Tertiary Military Medical Center

Background

Patients on ECMO are at higher risk for nosocomial infections. While several studies report on infections in ECMO patients, the epidemiology of infections in burn patients on ECMO has not been previously described.

Methods

A retrospective chart review was performed on all patients on ECMO for >48 hours at Brooke Army Medical Center and the U.S. Army Institute of Surgical Research Burn Center between 2012 and 2017. Patient demographics, burn status, ECMO characteristics, and infection incidence during ECMO were captured. Statistical analyses comparing burn vs. nonburn patients were performed using chi-squared, Fisher’s exact and Mann–Whitney U tests.

Results

In comparison with those without diagnosed infections, infected patients had more days on ECMO (median [IQR] 16 [12–20] vs. 6.5 [5–10], P < 0.01) and longer hospitalization (median [IQR] 35 [24–54] vs. 23.5 days [8–45], P = 0.06), however survival to hospital discharge was no different (64% vs. 58%, P = 0.77). Burn patients trended toward more infections in their ECMO course (table).

Conclusion

Infection is a common complication of ECMO and is associated with longer duration on ECMO and longer hospitalizations. Burn patients in this cohort were observed to have higher rates of infection compared with nonburn patients.

Disclosures

All authors: No reported disclosures.

Transorbital Penetrating Intracranial Injury Caused by Sheppard's Hook

Intracranial injury resulting from transorbital penetrating objects is rare in a noncombat setting. As such there is a significant lack of data pertaining to the management of non-projectile traumatic brain injuries due to foreign bodies entering the brain. Intracranial complications can include intracerebral hematoma, cerebral contusion, intraventricular hemorrhage, pneumocephalus, brain stem injury, and carotid cavernous sinus fistula. This is the first report of a transorbital penetrating intracranial injury caused by a Sheppard’s hook, which was managed utilizing a multi-disciplinary, non-operative approach.

Abdominal malignancies in patients with Wilson's disease

BACKGROUND

Wilson's disease is associated with heavy copper overload, primarily in the liver. Copper is a toxic metal, and might be expected to be associated with cancer induction, as iron is in haemochromatosis. However, liver cancer is currently believed to be extremely rare in this disease, and other intra-abdominal malignancies have not been reported.

AIM

To assess the frequency of abdominal malignant disease in patients with Wilson's disease on long-term follow-up.

DESIGN

Retrospective study in two specialist Wilson's disease clinics: Cambridge/London and Uppsala.

METHODS

We reviewed the case records of 363 patients seen at three centres: Addenbrooke's Hospital, Cambridge, 1955-1987; the Middlesex Hospital, London, 1987-2000; and the University Hospital, Uppsala, Sweden, 1966-2002. Patients were grouped by length of follow-up: 10-19 years; 20-29 years; 30-39 years; and 40 years or more.

RESULTS

No cancers were seen in patients followed for <10 years. For patients in the 10-19 years group, the frequency was 4.2%; at 20-29 years, it was 5.3%; and at 30-39 years, 15%. No cancers were seen in the 40+ years follow-up group. The cancers consisted of hepatomas, cholangiocarcinomas, and poorly differentiated adenocarcinomas of undetermined primary site.

DISCUSSION

Patients with Wilson's disease appear to be vulnerable to the formation of aggressive malignant intra-abdominal tumours during long-term follow-up, irrespective of treatment. Ultrasound scanning of the abdomen seems to be a useful screening procedure.

Organ pathology following mild hypothermia used as neural rescue therapy in newborn piglets

The aim of this study was to assess the possible adverse effects of hypothermia, used as neural rescue therapy in a newborn piglet model. Sixteen newborn piglets were subjected to transient cerebral hypoxia-ischaemia by temporary occlusion of the carotid arteries and reduction of the fractional inspired oxygen to 0.12. On resuscitation 11 piglets were maintained normothermic (38.5-39.0 degrees C) and, in order to assess the cerebroprotective effect of hypothermia, 5 piglets were cooled to 35 degrees C for 12 h before normothermia was resumed. At 48 or 64 h following resuscitation the animals were sacrificed and the heart, left kidney, specimens of distal small bowel, lung and liver were removed and histologically sectioned. No microscopic abnormalities of the heart, bowel or lung were observed in hypothermic or normothermic animals. All kidney specimens were normal except one from the normothermic group. Abnormal liver pathology suggestive of hypoperfusion injury was found in 5 normothermic and 3 hypothermic piglets. There was no significant difference in the proportion of piglets with liver abnormality between the two groups. Mild hypothermia following cerebral hypoxia-ischaemia in the newborn piglet was not associated with an increased incidence of non-cerebral organ damage. The hepatic injury observed may be related to umbilical venous catheterisation and has potential relevance to neonatal intensive care.

Effect of methylprednisolone on the ulceration, matrix metalloproteinase distribution and eicosanoid production in a model of colitis in the rabbit

This study has examined the response of a rabbit model of inflammatory bowel disease to methylprednisolone. Colitis was induced in the colon of rabbits with 40 mg trinitrobenzenesulphonic acid in 25% ethanol (TNBS). The effect of methylprednisolone (0.5 mg/kg/day) on the development of colitis was determined at one week, by examining the colon's macroscopic and microscopic appearance, the distribution of matrix metalloproteinases (MMPs) and by measuring eicosanoid production. Although there was no difference in the area of ulcerated colonic tissue in the treated and untreated TNBS animals, the increase in polymorphonuclear leucocytes was significantly reduced in TNBS rabbits given methylprednisolone. The only difference in the distribution of MMPs was a reduction in the number of polymorphonuclear leucocytes containing gelatinase B. The release of immunoreactive PGE2 and LTB4, but not 6-keto PGF1 alpha, was increased in the TNBS animals and was unchanged by methylprednisolone. These results show that methylprednisolone does not modify the injury produced by TNBS in this model despite reducing the infiltration of polymorphonuclear leucocytes. Hence it suggests that these cells do not contribute to the injury observed, are not the source of the eicosanoids and that gelatinase B is not required in the healing process in this model.

Nephrogenic rests and renal abnormalities in Brachmann-de Lange syndrome

We report renal abnormalities found in four cases of Brachmann-de Lange syndrome (BDLS). In two there were nephrogenic tests and renal cortical cysts, a further case showed cortical cysts, and the fourth had dilated collecting ducts. The literature describing renal abnormalities in BDLS has been reviewed, and this includes a report of one individual with BDLS who developed Wilms tumor. The genetic basis of BDLS has not been elucidated, although a submicroscopic abnormality of chromosome 3 seems likely. Nephrogenic rests may be Wilms' tumor precursor lesions and are seen in syndromes associated with Wilms' tumors. Mutations of genes on chromosome 11 are the most common genetic abnormalities associated with Wilms' tumor, but other chromosomes have also been implicated. The frequency of renal abnormalities in the BDLS suggests that the involved gene may be important in renal development and also possibly in Wilms' tumors.

The characterization of a rabbit model of inflammatory bowel disease

The absence of a simple, clinically relevant, animal model of inflammatory bowel disease (IBD) hampers research into this disease. In this study, colitis was induced in rabbits by intracolonic installation of 2,4,6-trinitrobenzene sulphonic acid (TNB) in 25% ethanol. Rabbits were killed from zero hours to 6 weeks and their colons examined. Rabbits were examined by endoscopy at weekly intervals. A single dose of TNB in ethanol produced dose dependent inflammation and ulceration, which at its optimum (40 mg) resulted in cobblestoning, strictures, and bowel wall thickening. The damage score at endoscopy was consistent with the score on macroscopic examination of the colon. Histopathological features of inflammation and ulceration observed in all animals that received 40 mg TNB included crypt abscesses, ulceration, crypt architectural distortion and, occasionally, granulomas and pseudopolyps. These changes, which are similar to those observed in IBD, persisted for 6 weeks. No lasting abnormalities were observed in control animals treated with TNB in saline, with ethanol alone, or with saline only. Histopathological similarity and the prolonged duration of inflammation, compared to other models, make this a suitable model for investigating inflammation in the colon. Furthermore, the model is accessible to endoscopy which adds to its value in experimental studies.

Lesions of schistosomiasis mimicking warts on the vulva

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Unusual lymphangioma observed prenatally in a 45,X fetus

We present a case of a large frontal lesion, suspected on antenatal ultrasound to be a cephalocele. The cardiac anatomy was abnormal and fetal blood sampling showed a 45,X chromosome constitution. Postmortem examination proved this to be a lymphangioma and confirmed the presence of a cardiac defect. We suggest that this lymphangioma represents an unusual manifestation of monosomy X and discuss the importance of doing chromosome analysis in the presence of such a lesion which is of similar appearance as a cephalocele.

Risks and benefits of percutaneous biopsy and primary chemotherapy in advanced Wilms' tumour

Between 1982 and 1988, 36 children with advanced Wilms' tumour underwent percutaneous trucut needle biopsy followed by chemotherapy before definitive surgery. Nephrectomy was performed after a median of 14 weeks of chemotherapy. Substantial reduction in tumour bulk was achieved in 94% of patients. Biopsy morbidity was low and complete concordance between the histological assessment of the tumour in the biopsy specimen and at subsequent nephrectomy was confirmed in 26 of 28 (93%) patients. The overall clinical value of trucut biopsy was 83% (30/36 patients). Survival rates in this high-risk group were comparable to those of children with less advanced disease. Chemotherapy may be the primary treatment of choice for patients with Wilms' tumour. Percutaneous biopsy allows definition of histology in most patients without increasing morbidity.

Treatment of severe self-injurious and aggressive biting

The treatment of a 16-year-old severely mentally retarded and blind female client exhibiting severe biting of self and others consisted of the contingent application of an aversive gustatory stimulus (Tabasco Sauce), brief timeout, DRO, and contingent restraint against biting while in time-out. This is the first use of Tabasco as the aversive stimulus against biting. Deceleration of biting was rapid and maintained for 20 months after initiation of treatment.