Survival of In-Hospital Cardiopulmonary Arrest in Trauma Patients

INTRODUCTION

Relative to other hospitalized patients, trauma patients are younger with fewer comorbidities, but the incidence and outcomes of in-hospital cardiopulmonary arrest (IHCA) with cardiopulmonary resuscitation (CPR) in this population is unknown. Therefore, we aimed to investigate factors associated with survival in trauma patients after IHCA to test the hypothesis that compared to other hospitalized patients, trauma patients with IHCA have improved survival.

METHODS

Retrospective review of the Trauma Quality Improvement Program database 2017 to 2019 for patients who had IHCA with CPR. Primary outcome was survival to hospital discharge. Secondary outcomes were in-hospital complications, hospital length of stay, intensive care unit length of stay, and ventilator days. Data were compared with univariate and multivariate analyses at P < 0.05.

RESULTS

In 22,346,677 admitted trauma patients, 14,056 (0.6%) received CPR. Four thousand three hundred seventy-seven (31.1%) survived to discharge versus 26.4% in a national sample of all hospitalized patients (P < 0.001). In trauma patients, median age was 55 y, the majority were male (72.2%). Mortality was higher for females versus males (70.3% versus 68.3%, P = 0.026). Multivariate regression showed that older age 1.01 (95% confidence interval (CI) 1.01-1.02), Hispanic ethnicity 1.21 (95% CI 1.04-1.40), and penetrating trauma 1.51 (95% CI 1.32-1.72) were risk factors for mortality, while White race was a protective factor 0.36 (95% CI 0.14-0.89).

CONCLUSIONS

This is the first study to show that the incidence of IHCA with CPR is approximately six in 1000 trauma admissions and 31% survive to hospital discharge, which is higher than other hospitalized patients. Age, gender, racial, and ethnic disparities also influence survival.

Admission to a Verified Pediatric Trauma Center is Associated With Improved Outcomes in Severely Injured Children

BACKGROUND

Previous studies have shown improved survival for severely injured adult patients treated at American College of Surgeons verified level I/II trauma centers compared to level III and undesignated centers. However, this relationship has not been well established in pediatric trauma centers (PTCs). We hypothesize that severely injured children will have lower mortality at verified level I/II PTCs compared to centers without PTC verification.

METHODS

All patients 1-15 years of age with ISS >15 in the 2017-2019 American College of Surgeons Trauma Quality Programs (ACS TQP) dataset were reviewed. Patients with pre-hospital cardiac arrest, burns, and those transferred out for ongoing inpatient care were excluded. Logistic regression models were used to assess the effects of pediatric trauma center verification on mortality.

RESULTS

16,301 patients were identified (64 % male, median ISS 21 [17-27]), and 60 % were admitted to verified PTCs. Overall mortality was 6.0 %. Mortality at centers with PTC verification was 5.1 % versus 7.3 % at centers without PTC verification (p < 0.001). After controlling for injury mechanism, sex, age, pediatric-adjusted shock index (SIPA), ISS, arrival via interhospital transfer, and adult trauma center verification, pediatric level I/II trauma center designation was independently associated with decreased mortality (OR 0.72, 95 % CI 0.61-0.85).

CONCLUSIONS

Treatment at ACS-verified pediatric trauma centers is associated with improved survival in critically injured children. These findings highlight the importance of PTC verification in optimizing outcomes for severely injured pediatric patients and should influence trauma center apportionment and prehospital triage.

LEVEL OF EVIDENCE

Level IV - Retrospective review of national database.

Evolutionary genomics of three agricultural pest moths reveals rapid evolution of host adaptation and immune-related genes

BACKGROUND

Understanding the genotype of pest species provides an important baseline for designing integrated pest management (IPM) strategies. Recently developed long-read sequence technologies make it possible to compare genomic features of nonmodel pest species to disclose the evolutionary path underlying the pest species profiles. Here we sequenced and assembled genomes for 3 agricultural pest gelechiid moths: Phthorimaea absoluta (tomato leafminer), Keiferia lycopersicella (tomato pinworm), and Scrobipalpa atriplicella (goosefoot groundling moth). We also compared genomes of tomato leafminer and tomato pinworm with published genomes of Phthorimaea operculella and Pectinophora gossypiella to investigate the gene family evolution related to the pest species profiles.

RESULTS

We found that the 3 solanaceous feeding species, P. absoluta, K. lycopersicella, and P. operculella, are clustered together. Gene family evolution analyses with the 4 species show clear gene family expansions on host plant-associated genes for the 3 solanaceous feeding species. These genes are involved in host compound sensing (e.g., gustatory receptors), detoxification (e.g., ABC transporter C family, cytochrome P450, glucose-methanol-choline oxidoreductase, insect cuticle proteins, and UDP-glucuronosyl), and digestion (e.g., serine proteases and peptidase family S1). A gene ontology enrichment analysis of rapid evolving genes also suggests enriched functions in host sensing and immunity.

CONCLUSIONS

Our results of family evolution analyses indicate that host plant adaptation and pathogen defense could be important drivers in species diversification among gelechiid moths.

CRISPR-based diagnostics detects invasive insect pests

Rapid identification of organisms is essential for many biological and medical disciplines, from understanding basic ecosystem processes, disease diagnosis, to the detection of invasive pests. CRISPR-based diagnostics offers a novel and rapid alternative to other identification methods and can revolutionize our ability to detect organisms with high accuracy. Here we describe a CRISPR-based diagnostic developed with the universal cytochrome-oxidase 1 gene (CO1). The CO1 gene is the most sequenced gene among Animalia, and therefore our approach can be adopted to detect nearly any animal. We tested the approach on three difficult-to-identify moth species (Keiferia lycopersicella, Phthorimaea absoluta and Scrobipalpa atriplicella) that are major invasive pests globally. We designed an assay that combines recombinase polymerase amplification (RPA) with CRISPR for signal generation. Our approach has a much higher sensitivity than real-time PCR assays and achieved 100% accuracy for identification of all three species, with a detection limit of up to 120 fM for P. absoluta and 400 fM for the other two species. Our approach does not require a sophisticated laboratory, reduces the risk of cross-contamination, and can be completed in less than 1 h. This work serves as a proof of concept that has the potential to revolutionize animal detection and monitoring.

CRISPR-based diagnostics detects invasive insect pests

Rapid identification of organisms is essential across many biological and medical disciplines, from understanding basic ecosystem processes and how organisms respond to environmental change, to disease diagnosis and detection of invasive pests. CRISPR-based diagnostics offers a novel and rapid alternative to other identification methods and can revolutionize our ability to detect organisms with high accuracy. Here we describe a CRISPR-based diagnostic developed with the universal cytochrome-oxidase 1 gene (CO1). The CO1 gene is the most sequenced gene among Animalia, and therefore our approach can be adopted to detect nearly any animal. We tested the approach on three difficult-to-identify moth species (Keiferia lycopersicella, Phthorimaea absoluta, and Scrobipalpa atriplicella) that are major invasive pests globally. We designed an assay that combines recombinase polymerase amplification (RPA) with CRISPR for signal generation. Our approach has a much higher sensitivity than other real time-PCR assays and achieved 100% accuracy for identification of all three species, with a detection limit of up to 120 fM for P. absoluta and 400 fM for the other two species. Our approach does not require a lab setting, reduces the risk of cross-contamination, and can be completed in less than one hour. This work serves as a proof of concept that has the potential to revolutionize animal detection and monitoring.

Improved Survival for Severely Injured Patients Receiving Massive Transfusion at US Teaching Hospitals: A Nationwide Analysis

BACKGROUND

Previous studies have shown improved survival for patients treated at American College of Surgeons (ACS) verified level I trauma centers compared to level II, level III, and undesignated centers. This mortality difference is more pronounced in severely injured patients. However, a survival benefit for severely injured trauma patients has not been established at teaching institutions compared to non-teaching centers. As massive transfusion (MT) is associated with high mortality, we hypothesize that patients receiving MT have lower mortality at teaching hospitals than at non-teaching hospitals.

METHODS

All adult ACS Trauma Quality Improvement Program-eligible patients who underwent MT, defined as >10 units of packed red blood cells in the first 4 hours after arrival, in the 2019 ACS Trauma Quality Programs participant use file were eligible. Patients with severe head injury (AIS Head ≥3), prehospital cardiac arrest, and interhospital transfers were excluded. Logistic regression models were used to assess the effects of trauma center hospital teaching status on the adjusted odds of 3-hour, 6-hour, and 24-hour mortality.

RESULTS

1,849 patients received MT [81% male, median ISS 26 (18-35)], 72% were admitted to level I trauma centers, and 28% were admitted to level II centers. Overall hospital mortality was 41%; 17% of patients died in 3 hours, 25% in 6 hours and 33% in 24 hours. Teaching hospitals were associated with decreased 3-hour (OR 0.45, 95% CI 0.27-0.75), 6-hour (OR 0.37, 95% CI 0.24-0.56), 24-hour (OR 0.50, 95% CI 0.34-0.75), and overall mortality (OR 0.66, 95% CI 0.44-0.98), compared to non-teaching hospitals, controlling for sex, age, heart rate, injury severity, injury mechanism, and trauma center verification level.

CONCLUSIONS

Severely injured patients requiring MT experience significantly lower mortality at teaching hospitals compared to non-teaching hospitals, independently of trauma center verification level.

LEVEL OF EVIDENCE

Level III: Retrospective comparative study.

Ticks as novel sentinels to monitor environmental levels of per- and polyfluoroalkyl substances (PFAS)

Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent, ubiquitous pollutants. It is important to continuously monitor the presence of PFAS contamination, utilizing both legacy and new sentinels. In this study, environmental PFAS levels were evaluated using ticks as a sentinel model due to their world-wide distribution, hematophagous nature, and ease of collection and sampling. Hematophagy in discrete blood meals, from a suite of vertebrates, allows ticks to sample dozens of species of consumers and bioaccumulation across communities. Four different species of ticks, across two states (NY, n = 28 in mid-April of 2020 and FL, n = 32 between 2015 and 2020) with two sampling sites in each state were analyzed for the presence of 53 PFAS. The total PFAS concentration in ticks was the lowest at Newburgh (NY), a site that has been undergoing remediation efforts, while the highest total PFAS concentrations were measured in ticks at the Sweetwater site, a wastewater treatment wetland. Detection of PFAS and the potential for variation between tick species and between locations are necessary to establish the utility of ticks as sentinels, in addition to assessing additional environmental factors, such as other wildlife, water, or soil.

Arterial or cuff pressure: Clinical predictors among patients in shock in a critical care resuscitation unit

OBJECTIVES

Blood pressure (BP) measurement is essential for managing patients with hypotension. There are differences between invasive arterial blood pressure (IABP) and noninvasive blood pressure (NIBP) measurements. However, the clinical applicability of these differences in patients with shock [need for vasopressor or serum lactate ≥ 4 millimole per liter (mmol/L)] has not been reported. This study investigated differences in IABP and NIBP as well as changes in clinical management in critically ill patients with shock.

METHODS

This was a retrospective study involving adult patients admitted to the Critical Care Resuscitation Unit (CCRU). Adult patients who received IABP upon admission between 01/01/2017-12/31/2017 with non-hypertensive diseases were eligible. The primary outcome, clinically relevant difference (CRD), was defined as difference of 10 mm of mercury (mmHg) between IABP and NIBP and change of blood pressure management according to goal mean arterial pressure (MAP) ≥ 65 mmHg. We performed forward stepwise multivariable logistic regression to measure associations.

RESULTS

Sample size calculation recommended 200 patients, and we analyzed 263. 121 (46%) patients had shock, 23 (9%) patients had CRD. Each mmol/L increase in serum lactate was associated with 11% higher likelihood of having CRD (OR 1.11, 95%CI 1.002-1.2). Peripheral artery disease and any kidney disease was significantly associated with higher likelihood of MAP difference ≥ 10 mmHg.

CONCLUSION

Approximately 9% of patients with shock had clinically-relevant MAP difference. Higher serum lactate was associated with higher likelihood of CRD. Until further studies are available, clinicians should consider using IABP in patients with shock.

Single Center Experience With Veno-Venous Extracorporeal Membrane Oxygenation in Patients With Traumatic Brain Injury

METHODS

We retrospectively reviewed TBI patients ≥ 18 years of age treated with VV-ECMO. The primary outcome was survival to discharge. Secondary outcomes included progression of intracranial hemorrhage, bleeding complications, and episodes of oxygenator thrombosis requiring exchange. Medians and interquartile ranges were reported where appropriate.

RESULTS

13 TBI patients received VV-ECMO support during the study period. The median age was 28 years (Interquartile range (IQR) 25-37.5) and 85% were men. Median admission Glasgow coma scale was 5 (IQR 3-13.5). Median injury severity score (ISS) was 48 (IQR 33.5-66). Median pre-ECMO PaO2:FiO2 ratio was 58 (IQR 47-74.5). Five (38.4%) patients survived to discharge. Six patients (46%) received systemic A/C while on ECMO. No patient had worsening of intracranial hemorrhage on computed tomography imaging. There were two bleeding complications in patients on A/C, neither was related to TBI. Four patients required an oxygenator change; 2 in patients on A/C.

CONCLUSION

VV-ECMO appears safe with TBI. We have demonstrated that A/C can be withheld without increased complications. Traumatic brain injury should not be considered an absolute contraindication to the use of VV-ECMO for severe respiratory failure and should be decided on a case by case basis. Additional research is needed to confirm these preliminary findings.

Dispersal and Land Cover Contribute to Pseudorabies Virus Exposure in Invasive Wild Pigs

We investigated the landscape epidemiology of a globally distributed mammal, the wild pig (Sus scrofa), in Florida (U.S.), where it is considered an invasive species and reservoir to pathogens that impact the health of people, domestic animals, and wildlife. Specifically, we tested the hypothesis that two commonly cited factors in disease transmission, connectivity among populations and abundant resources, would increase the likelihood of exposure to both pseudorabies virus (PrV) and Brucella spp. (bacterial agent of brucellosis) in wild pigs across the Kissimmee Valley of Florida. Using DNA from 348 wild pigs and sera from 320 individuals at 24 sites, we employed population genetic techniques to infer individual dispersal, and an Akaike information criterion framework to compare candidate logistic regression models that incorporated both dispersal and land cover composition. Our findings suggested that recent dispersal conferred higher odds of exposure to PrV, but not Brucella spp., among wild pigs throughout the Kissimmee Valley region. Odds of exposure also increased in association with agriculture and open canopy pine, prairie, and scrub habitats, likely because of highly localized resources within those land cover types. Because the effect of open canopy on PrV exposure reversed when agricultural cover was available, we suggest that small-scale resource distribution may be more important than overall resource abundance. Our results underscore the importance of studying and managing disease dynamics through multiple processes and spatial scales, particularly for non-native pathogens that threaten wildlife conservation, economy, and public health.

Intoxication and overdose should not preclude veno-venous extracorporeal membrane oxygenation

Introduction

Acute intoxication (AI) related morbidity and mortality are increasing in the United States. For patients with severe respiratory failure in the setting of an acute ingestion, veno-venous extracorporeal membrane oxygenation (VV ECMO) can provide salvage therapy. The purpose of this study was to evaluate outcomes in patients with overdose-related need for VV ECMO.

Methods:

We performed a retrospective review of all patients admitted to a specialty VV ECMO unit between August 2014 and August 2018. Patients were stratified by those whose indication for VV ECMO was directly related to an acute ingestion (alcohol, illicit drug, or prescription drug overdose) and those with unrelated diagnoses. Demographics, pre-cannulation clinical characteristics, ECMO parameters, and outcomes data was collected and analyzed with parametric and non-parametric statistics as indicated.

Results:

189 patients were enrolled with 27 (14%) diagnosed with AI. Patients requiring VV ECMO for an AI were younger, had lower median BMI and PaO2/FiO2, and higher RESP scores than non-AI patients (p = 0.002, 0.01, 0.03 and 0.01). There was no difference in pre-cannulation pH, lactate, or SOFA scores between the two groups (p = 0.24, 0.5, 0.6). There was no difference in survival to discharge (p = 0.95). Among survivors, there was no difference in ECMO time or hospital stay (p = 0.24, 0.07).

Conclusion:

We demonstrate no survival difference for patients with and without an AI-related need for VV ECMO. AI patients should be supported with VV ECMO when traditional therapies fail despite potential stigma against acceptance on referral.

Stop the Bleed: Does the Training Work One Month Out?

The Stop the Bleed initiative empowers and trains citizens as immediate responders, to recognize and control severe hemorrhage. We sought to determine the retention of short-term knowledge and ability to apply a Combat Application Tourniquet (CAT) in 10 nonmedical personnel. A standard "Stop the Bleed" (Bleeding Control) course was taught including CAT application. Posttraining performance was assessed at 30 days using a standardized mannequin with a traumatic below-knee amputation. Technique, time, pitfalls, and feedback were all recorded. No participant had placed a CAT before the initial class. After the initial class, self-report by a Likert scale survey revealed an increased confidence in tourniquet application from 2.4 pretraining to 4.7 posttraining. At 30 days, confidence decreased to 3.4 before testing. Six of 10 were successful at tourniquet placement. Completion time was 77.75 seconds (43-157 seconds). Successful participants reported a confidence level of 4.7 versus those unsuccessful at 3.3. The "Stop the Bleed" initiative teaches lifesaving skills to the public through a short training course. This information regarding the training of nonmedical personnel may assist in strengthening training efforts for the public. Further investigations are needed to characterize skill degradation and retention over time.

Stop the Bleed: Does the Training Work One Month Out?

The Stop the Bleed initiative empowers and trains citizens as immediate responders, to recognize and control severe hemorrhage. We sought to determine the retention of short-term knowledge and ability to apply a Combat Application Tourniquet (CAT) in 10 nonmedical personnel. A standard “Stop the Bleed” (Bleeding Control) course was taught including CAT application. Posttraining performance was assessed at 30 days using a standardized mannequin with a traumatic below-knee amputation. Technique, time, pitfalls, and feedback were all recorded. No participant had placed a CAT before the initial class. After the initial class, self-report by a Likert scale survey revealed an increased confidence in tourniquet application from 2.4 pretraining to 4.7 posttraining. At 30 days, confidence decreased to 3.4 before testing. Six of 10 were successful at tourniquet placement. Completion time was 77.75 seconds (43–157 seconds). Successful participants reported a confidence level of 4.7 versus those unsuccessful at 3.3. The “Stop the Bleed” initiative teaches lifesaving skills to the public through a short training course. This information regarding the training of nonmedical personnel may assist in strengthening training efforts for the public. Further investigations are needed to characterize skill degradation and retention over time.

Use of tissue plasminogen activator in liver transplantation from donation after cardiac death donors

Ischemic-type biliary stricture (ITBS) occurs in up to 50% after liver transplantation (LT) from donation after cardiac death (DCD) donors. Thrombus formation in the peribiliary microcirculation is a postulated mechanism. The aim was to describe our experience of tissue plasminogen activator (TPA) administration in DCD-LT. TPA was injected into the donor hepatic artery on the backtable (n = 22). Two recipients developed ITBS including one graft failure. Although excessive postreperfusion bleeding was seen in 14 recipients, the amount of TPA was comparable between those with and without excessive bleeding (6.4 ± 2.8 vs. 6.6 ± 2.8 mg, p = 0.78). However, donor age (41 ± 12 vs. 29 ± 9 years, p = 0.02), donor BMI (26.3 ± 5.5 vs. 21.7 ± 3.6 kg/m(2) , p = 0.03), previous laparotomy (50% vs. 0%, p = 0.02) and lactate after portal reperfusion (6.3 ± 4.6 vs. 2.8 ± 0.9 mmol/L, p = 0.005) were significantly greater in recipients with excessive bleeding. In conclusion, the use of TPA may lower the risk of ITBS-related graft failure in DCD-LT. Excessive bleeding may be related to poor graft quality and previous laparotomy rather than the amount of TPA. Further studies are needed in larger population.

Central venous pressure during the post-anhepatic phase is not associated with early postoperative outcomes following orthotopic liver transplantation

BACKGROUND

Fluid management during orthotopic liver transplantation poses unique challenges for the anesthesiologist. Maintenance of hypovolemia as indicated by low central venous pressure has been associated with reduced blood loss and improved outcomes in some studies, but with higher 30-day mortality and increased incidence of renal dysfunction in others. The primary aim was to evaluate the association of central venous pressure management after liver allograft reperfusion with immediate postoperative patient outcomes.

METHODS

This was a retrospective investigation evaluating the intraoperative and postoperative records of 144 consecutive patients who underwent orthotopic liver transplantation at a single institution.

RESULTS

We did not find any important association between central venous pressure management after graft reperfusion and postoperative patient outcomes. Specifically, these data do not support the hypothesis that maintenance of lower central venous pressure during the post-anhepatic phase of orthotopic liver transplantation is associated with improved immediate postoperative allograft function (except for a steeper decrease in post operative days 1-3 in 2 of the 3 liver function test: alanine aminotransferase and bilirubin) or overall patient survival, graft survival, composite graft/patient survival, intensive care length of stay, hospital length of stay or the occurrence of infections.

CONCLUSION

Maintaining a lower central venous pressure during the post-anhepatic phase during orthotopic liver transplantation is not associated with any benefit in terms of immediate postoperative allograft function, graft survival or patient survival.

Density and distribution of Dirofilaria immitis (Nematoda: Filarioidea) third-stage larvae in Aedes sollicitans and Aedes taeniorhynchus (Diptera: Culicidae)

Numbers and the distribution of third-stage larvae (L3) were investigated in Aedes sollicitans (Walker) and Aedes taeniorhynchus (Wiedemann) female mosquitoes fed Dirofilaria immitis (Leidy) infectious-blood with densities of microfilariae (mf) ranging from approximately 7,100-43,400 mf/ml. At each microfilarial density, a maximum of 63-66 infective larvae were recovered from an Ae. sollicitans alive on day 15 after infection. In comparison with Ae. taeniorhynchus, Ae. sollicitans averaged greater numbers of L3 and from 1.4 to 2.4 times more L3 in the head and labium per infected female. The trend was for greater numbers of L3 to be found in the labium than in the head of Ae. sollicitans, but there were no significant differences between numbers of L3 recovered from these sites in differentially infected females. However, numbers of L3 recovered from the head versus the labium of differentially infected Ae. taeniorhynchus varied significantly with the infectious blood microfilarial density. At the two lowest and highest microfilarial densities, greater numbers of L3 were recovered from the head and labium, respectively. Variations among species in the female body size, blood meal size, and retention of L3 may be factors responsible for differences observed between the total numbers and percentage distribution of D. immitis L3 recovered from the simultaneous blood-fed Ae. sollicitans and Ae. taeniorhynchus.

Redefining the preoperative evaluation process and the role of the anesthesiologist

STUDY OBJECTIVE

To assess the effects of implementing an ambulatory and same-day surgery preoperative evaluation patient triage system over a 3-year period.

DESIGN

Retrospective analysis of 63,941 ambulatory surgical patients presenting for elective surgery.

SETTING

Tertiary care, academic medical institution.

INTERVENTIONS

The following preoperative evaluation model components were implemented over a 3-year period: HealthQuest, which is an outpatient preoperative assessment computer program developed by the Department of General Anesthesiology; a general internal medicine clinic designated specifically for preoperative evaluation and medical optimization; disease specific algorithms for both preoperative patient assessment and management; and a preoperative anesthesia clinic that no longer performs preoperative medical optimization.

MEASUREMENTS AND MAIN RESULTS

During the 3-year study period ambulatory and same-day surgical case volume increased 34.7%. A total of 50,967 patients used HealthQuest as part of their preoperative evaluation. Of these patients 22,744 (35.6%) did not need to see an anesthesiologist until the day of surgery as guided by both a computer-assigned HealthQuest score and surgical classification scheme. Also, 41,197 patients were evaluated in our anesthesia preoperative clinic with a cost per evaluation of $24.86, which increased only 0.9% per year. In addition, both patient interview time and patient dissatisfaction with the preoperative process decreased over the 3-year period. There were 20, 088 patient encounters in the general internal medicine clinic for patient medical evaluation and optimization. The average monthly preoperative surgical delay rate decreased 49% during the study period. Finally, significant monetary saving resulted due to decreased unnecessary laboratory testing.

CONCLUSIONS

Efficient, cost-effective patient care can be provided by using this preoperative evaluation model. Some institutions may find portions of this preoperative model applicable to their current situation.

Autonomic dysfunction in end-stage liver disease manifested as defecation syncope: impact of orthotopic liver transplantation

Patients with end-stage liver disease (ESLD) may be at increased risk for syncopal episodes based on their circulatory physiological state. Although a definitive cause for this is not known, several mechanisms have been proposed. In patients with ESLD, defecation syncope may result from a failure of short-term neurocirculatory adaptation to the Valsalva maneuver in the face of a hyperdynamic circulatory state and a decreased effective intravascular volume. We describe 2 patients with ESLD who had repeated episodes of defecation syncope before orthotopic liver transplantation (OLT). The most effective treatment of these syncopal episodes appears to be fluid administration and the use of a pressor agent, such as dopamine, to help maintain both an effective heart rate and intravascular volume. Correction of this altered circulatory physiological state through OLT prevented further syncopal episodes in both patients. A search of the literature failed to show previous reports associating ESLD and defecation syncope. Possible mechanisms favoring this association are reviewed.

Is there occult tissue ischemia in chronic end-stage liver disease?

Whether pathological oxygen supply dependency exists in patients with chronic end-stage liver disease (CESLD) is unknown, although the frequently occurring multiorgan dysfunction seen in these patients may be the result of occult tissue ischemia. In this study, 15 adult patients with CESLD were evaluated for the presence of pathological oxygen supply dependency and, thus, occult tissue ischemia before undergoing orthotopic liver transplantation. Whole-body oxygen consumption (VO2) was measured using indirect calorimetry at baseline, at reduced oxygen delivery (DO2) using positive end-expiratory pressure, and at increased DO2 using volume infusion. As a group, no significant increase or decrease in VO2 was observed with changes in DO2. However, 4 patients showed increases in VO2 of 14%, 10.8%, 9.6%, and 8.2% when DO2 was increased. The study results suggest that pathological oxygen supply dependency is present in a subset of patients with CESLD, and the existence of occult tissue ischemia is speculated.

Incidence and predictors of supraventricular dysrhythmias after pulmonary resection

BACKGROUND

Patients undergoing pulmonary resection were evaluated prospectively in an effort to determine the incidence of and predictors for the development of postoperative supraventricular dysrhythmias. Specifically, we wished to test the hypothesis that the incidence of postoperative supraventricular dysrhythmias is dependent on the magnitude of pulmonary resection.

METHODS

One hundred sixteen patients undergoing pulmonary resection had continuous Holter monitoring preoperatively, the day of operation, and the second postoperative day, as well as continuous cardiac monitoring throughout hospitalization. Holter interpretation was blinded to extent of resection.

RESULTS

Twenty-six patients underwent pneumonectomy, 7 bilobectomy, 47 lobectomy, and 36 wedge resection. Twenty-six patients (22.4%) had supraventricular dysrhythmias, all atrial fibrillation +/- flutter. The incidence of atrial fibrillation with pneumonectomy, bilobectomy, single lobectomy, and wedge resection was 46.1%, 14.3%, 17.0%, and 13.8%, respectively (p < 0.005 pneumonectomy versus others). Overall, 31% of patients having pneumonectomy required pharmacologic therapy for dysrhythmia compared with 16% of patients having lesser resections, (p = 0.03). The peak incidence of onset of atrial fibrillation occurred on postoperative days 2 and 3 and lasted for less than 1 to 7 days, average 2.5 days. The average age of patients with dysrhythmias (64 years) was greater than those without (58 years) (p = 0.039). Thirty pre- and postoperative variables tested were not found to be significant predictors for development of postoperative atrial fibrillation.

CONCLUSIONS

Atrial fibrillation occurs commonly after pulmonary resections but is not predictable. Development of atrial fibrillation is not dependent on the magnitude of pulmonary resection but is associated with the procedure pneumonectomy for reasons not elucidated.

Sharps disposal in the operating room: current clinical practices and costs

In the evolving medical environment, fiscal constraints on medical practice are becoming the norm. The new days of austerity have revived interest in the economics of medical practice. Economic measures, however, should not impinge on the quality of patient care. Waste disposal, in particular, is an area without any direct patient benefit but which carries both short- and long-term ecological costs. Much of how we dispose of waste is dictated in the United States by the Joint Commission for the Accreditation of Hospital Organization, Occupational Safety and Health Administration, state regulations, and individual hospital protocols. In an attempt to elucidate the waste in waste management, we examined the use of standard operating room sharp boxes. Full sharp boxes from three different operating sites were randomly saved. Boxes were weighed and opened, and contents were separated into appropriate sharps: loose needles, scalpels, syringes with uncapped needles, and other. Weight and volume assessments were performed on the nonsharps. True sharp values were derived from nonsharps data. Less than 50% of the contents were appropriate for sharps disposal, with empty glass vials constituting the greatest percentage by weight of nonsharps material. We believe that encouraging the appropriate use of sharps boxes is a potential source for savings.

IMPLICATIONS

Sharp boxes were randomly saved from university operating rooms and analyzed for content. The full boxes contained 14% appropriate sharps by weight and <50% appropriate sharps by volume. The largest fraction of nonsharps weight was found to be glass.

Aging and drug interactions. III. Individual and combined effects of cimetidine and cimetidine and ciprofloxacin on theophylline metabolism in healthy male and female nonsmokers

The individual and combined effects of cimetidine and ciprofloxacin on theophylline metabolism were examined in healthy young and elderly male and female nonsmokers. Single-dose studies of theophylline pharmacokinetics were performed at base line and on the fifth day of each of three treatment regimens consisting of 400 mg cimetidine every 12 hr, 500 mg ciprofloxacin every 12 hr and the combination of cimetidine and ciprofloxacin. Base-line theophylline plasma clearance and formation clearance of theophylline metabolites decreased with age in both gender groups to a similar extent (20% less in elderly men than in young men; 24% less in elderly women than in young women). Individually, cimetidine and ciprofloxacin produced proportionate declines in plasma theophylline clearance that were similar among the four groups (range, 23.4-32.7% decrease). The combined regimen yielded further impairment in theophylline elimination compared with each agent alone (range, 35.9-42.6% decrease). Cimetidine was a nonselective inhibitor of theophylline metabolic pathways in young men, but it exerted a greater inhibitory effect on N-demethylation pathways in the other groups. Ciprofloxacin inhibited N-demethylations of theophylline to a greater extent than the hydroxylation pathway. Coadministration of these two inhibitors further reduced the formation of theophylline metabolites. The proportionate reduction in formation clearance of theophylline metabolites was similar among the four groups. Thus, the response to inhibition of theophylline metabolism by cimetidine and ciprofloxacin is not influenced by age or gender.

Relation between plasma and saliva concentrations of enoxacin, ciprofloxacin, and theophylline

To assess the reliability of predicting plasma concentrations of enoxacin, ciprofloxacin, and theophylline from drug concentrations in saliva, six healthy volunteers received single oral doses of enoxacin, ciprofloxacin, and theophylline administered in combination on each of four separate study days, with different, doses separated by at least 5 days. Drug concentrations were determined by a newly developed high-performance liquid chromatography (HPLC) assay, which could measure simultaneously all three drugs in plasma or saliva. Saliva data from the postabsorptive phase after drug administration were used to minimize the effects of variation in absorption. There were good correlations between saliva and plasma concentrations of enoxacin, ciprofloxacin, and theophylline (r = 0.91, 0.88, and 0.98, respectively). The mean (+/-SD) saliva-to-plasma (S/P) ratio for theophylline was 0.63 +/- 0.06 with a coefficient of variation (CV) of 7.9 +/- 2.7%. In contrast, the S/P ratios and CV values for enoxacin and ciprofloxacin were 0.72 +/- 0.21 and 28.9 +/- 11.1%, and 0.58 +/- 0.15 and 25.3 +/- 6.7%, respectively. Because of the large inter- and intraindividual variability, saliva concentrations of enoxacin and ciprofloxacin are not reliable for predicting plasma concentrations. However, saliva may be used reliably for predicting plasma concentrations of theophylline.

Pharmacokinetic optimisation of drug therapy in elderly patients

With increasing age, there are a number of physiological changes that affect the handling of drugs in the human body. Increases in body fat percentage as well as decreases in lean body mass, hepatic metabolism and renal elimination capacity are of particular clinical significance. It is important to take these changes into account when choosing drug therapy for older patients in order to minimise adverse effects and maximise potential benefits. This is particularly important when prescribing drugs with a narrow therapeutic index such as digoxin, theophylline, phenytoin, lidocaine (lignocaine) or warfarin. When available, monitoring of plasma concentrations can assist in the optimisation of drug dosage.

Epidural analgesia versus intravenous patient-controlled analgesia. Differences in the postoperative course of cancer patients

BACKGROUND AND OBJECTIVES

This study evaluated 462 consecutive surgical cancer patients who underwent uncomplicated surgeries of the thorax or abdomen, or both, of more than 3 hours duration between 1989 and 1991.

METHODS

Patients received either epidural analgesia (EA group) with 0.1% bupivacaine, 0.01% morphine sulfate after combined general-epidural anesthesia, or parenteral morphine therapy via intravenous patient-controlled analgesia (IV-PCA) after balanced general anesthesia after the operation. Patients in both the EA (n = 352) and IV-PCA (n = 100) groups were compared for demographics, length of surgical intensive care unit (SICU), and hospital stays. Moreover, the same comparisons were performed when patients were allocated into surgical subgroups: thoracic (TH), upper abdominal (UA), lower abdominal (LA), radical hysterectomies (RH), and RH with colon resection (RHCR).

RESULTS

No differences existed with respect to age or sex between the EA and IV-PCA groups. All patients reported adequate dynamic pain control as evaluated with visual analog pain scores (VAS < 4/10), during the treatment periods (5 +/- 3 versus 5 +/- 2 days, EA versus IV-PCA). Overall, 262 (58%) patients were admitted to the SICU after the operation, 205 (58%) from the EA group and 57 (57%) from the IV-PCA group. Patients in the EA group required less ventilatory support than did those in the IV-PCA group (0.5 +/- 0.8 versus 1.2 +/- 0.9 days, P < .05). Patients in the EA group also spent less time in both the SICU (1.3 +/- 0.8 versus 2.8 +/- 0.6 days, P < .05) and in the hospital (11 +/- 3 versus 17 +/- 5 days, P < .05) than did their counterparts in the IV-PCA group. Significant differences were also found when subgroup comparisons were made.

CONCLUSIONS

The use of both analgesic techniques was associated with satisfactory postoperative pain control. However, patients receiving epidural anesthesia and analgesia experienced faster recovery as judged by shorter mechanical ventilation time, and decreased SICU and hospital stays, resulting in significantly lower hospitalization costs. The use of perioperative epidural techniques should be considered to expedite recovery of surgical patients, and has the added benefit of being cost effective by reducing hospital stays.

Ileoanal teaching tools: developing a tool to meet a specific need

As ET nurses working with ileoanal surgery patients for the first time in 1979, we discovered that there were no tools or materials available for teaching our patients how to care for themselves during the various stages of the procedure. Over the years, therefore, we have created a compilation of data based on answers to questionnaires completed by recent patients. This data base contains information on topics such as skin care and diet, and enables us to create teaching tools tailored to our own patient population. Although there are now other materials available for teaching self-care to ileoanal surgery patients, the ongoing collection of data from a particular group of patients can also help to create valuable teaching tools and enhance overall understanding of this complex procedure.

Individual and combined effects of cimetidine and ciprofloxacin on theophylline metabolism in male nonsmokers

1. The individual and combined effects of cimetidine and ciprofloxacin on theophylline metabolism were examined in six young male nonsmokers. 2. Treatment sequence consisted of 7 days each of cimetidine 400 mg p.o. every 12 h. ciprofloxacin 500 mg p.o. every 12 h, and the combination of cimetidine and ciprofloxacin. 3. Studies of theophylline pharmacokinetics were performed at baseline and on the fifth day of each regimen. 4. Individually, cimetidine and ciprofloxacin decreased the clearance of theophylline by 25% and 32%, respectively. Therapy with the combined regimen resulted in a 41% reduction in theophylline clearance, which was greater than that achieved with each drug alone (P < 0.01). 5. Ciprofloxacin, in contrast to cimetidine, inhibited N-demethylations of theophylline to a significantly greater extent than the hydroxylation pathway. Combined treatment produced a further decline in formation of 1,3-dimethyluric acid than each drug alone. 6. These data suggest that coadministration of cimetidine and ciprofloxacin exerts a greater impairment of theophylline biotransformation than each inhibitor alone. The enhanced inhibitory effect from the two inhibitors will occur only when sub-maximal doses of each individual agent are used.

The effect of tocainide on theophylline metabolism

The effect of 5 days of oral tocainide (400 mg every 8 h) on the kinetics of theophylline given as a single 5 mg kg-1 i.v. infusion over 30 min was investigated in eight healthy male nonsmokers. Treatment with tocainide decreased the plasma clearance of theophylline from 37.5 +/- 6.9 (mean +/- s.d.) to 33.7 +/- 5.0 ml kg-1 h-1 (difference -3.8, 95% CI, -1.7 to -5.9; P = 0.004) and increased its terminal elimination half-life from 9.7 +/- 2.5 to 10.4 +/- 2.1 h (difference 0.7, 95% CI, 0.2 to 1.2; P = 0.011). Tocainide decreased the formation clearances of 3-methylxanthine and 1-methyluric acid, but the formation clearance of 1,3-dimethyluric acid was unaltered. These data indicate that tocainide exerts a modest inhibitory effect on theophylline metabolism. The magnitude of this change is substantially smaller than that reported to be produced by mexiletine.

Variation of mosquito (Diptera: Culicidae) relative abundance and Dirofilaria immitis (Nematoda: Filarioidea) vector potential in coastal North Carolina

At an enzootic focus of Dirofilaria immitis in coastal North Carolina, mosquito populations were sampled June-September 1985 and on several occasions during August-October 1986 and June-August 1987, to identify local vectors and to determine relative abundance and D. immitis infection rates. Predominant species collected were Anopheles bradleyi King (66.6%), Culex salinarius Coquillett (15.9%), Aedes taeniorhynchus (Wiedemann) (8.2%), and Aedes sollicitans (Walker) (4.9%). Population abundance varied within and among seasons. D. immitis infection was found in An. bradleyi (1.2%), Ae. taeniorhynchus (0.9%), and Ae. sollicitans (0.9%). Of infected An. bradleyi, 88% were collected June-2 July, whereas the highest number of infected Ae. taeniorhynchus and Ae. sollicitans were found during mid-July 1985. Ae. sollicitans and Ae. taeniorhynchus were the only infected species found during 1986 and 1987. However, based on overall relative abundance and infective rate, An. bradleyi appeared to be the primary vector of D. immitis in the study area.

Can patients with chest pain and normal coronary arteries be discriminated from those with coronary artery disease prior to coronary angiography?

To determine whether the precatheterization clinical data in patients with chest pain could be used to discriminate patients with normal coronary arteries (NCA) from those with coronary artery disease, the authors compared 125 consecutive patients with less than 30% stenosis of all major coronary arteries and 125 patients with greater than 60% stenosis of one or more major coronary arteries. Clinical characteristics that occurred more frequently in patients with NCA were: nonexertional pain, pain to the left of the sternum, sharp pain, associated palpitations, absence of typical relief with sublingual nitroglycerin, pain commencing less than one week or more than ten years prior to coronary angiography, a normal electrocardiogram, and negative results from a treadmill stress test or from thallium scintigraphy. However, none of these clinical features, either singly or in combination, could be used to identify the patients with NCA with certainty.

Pulmonary hemodynamics in systemic hypertension

We reviewed cardiac catheterization data and the medical records of 30 patients with systemic hypertension to establish their pulmonary hemodynamic profiles and the relationship between certain clinical and demographic variables and increased pulmonary vascular resistance. Mean systemic arterial pressure ranged from 110 to 210 mm Hg, and systemic vascular resistance ranged from 17.6 to 47.0 units. Seven patients had normal pulmonary wedge pressure and normal pulmonary vascular resistance, one had elevated pulmonary wedge pressure and normal pulmonary vascular resistance, five had elevated pulmonary wedge pressure and increased pulmonary vascular resistance, and 17 had normal pulmonary wedge pressure and increased pulmonary vascular resistance. There were significant positive correlations between systemic vascular resistance and pulmonary vascular resistance and between mean systemic arterial pressure and mean pulmonary artery pressure, but there was no correlation between mean pulmonary wedge pressure and pulmonary vascular resistance. Of the 17 patients with normal pulmonary wedge pressure and increased pulmonary vascular resistance, seven had clinical or radiologic evidence of prior left ventricular failure. We conclude that increased pulmonary vascular resistance occurs commonly in patients with systemic hypertension. Although some cases of increased pulmonary vascular resistance relate to active or preexistent left ventricular failure, the majority remain unexplained, suggesting that neurohumoral or other factors may produce a hypertensive response in both the systemic and pulmonary arterial circuit.

The effect of myocardial preservation technique on operative mortality in complex valvular heart disease

Between November, 1964 and January, 1983, 70 consecutive patients underwent primary repair of complex valvular heart disease, defined as repair or replacement of two or more cardiac values alone or with other concomitant cardiac procedures. A total of 163 operative procedures were performed on the 70 patients for an average of 2.33 procedures per patient. Review of these cases allowed the patients to be divided into two distinct groups, those receiving systemic hypothermia and cold potassium cardioplegic arrest of the heart (C) and those having other myocardial preservation techniques (NC). Thirty-three patients received C and are compared with 37 patients who received NC. The two patient groups were comparable when considered for preoperative cardiac index and functional classification though patients in C group were older. In the C group, 10 of 32 patients (31%) had associated coronary artery bypass grafting in contrast to 2 of 37 patients (5.4%) in the NC era. The mortality of the C group was 2 of 33 (6%) vs 14 of 37 (37.8%) in the NC group (P less than .001). Of the 14 deaths in the NC patients, 10 were due to low cardiac output syndrome. While other factors have undoubtedly played a role, improved myocardial preservation by the use of C and attention to coronary artery pathology may have contributed to the improved operative mortality in this group of patients with complex valvular heart disease.

Lectin-dependent cell-mediated cytotoxicity: assessment of cytotoxic reactivity following challenge with syngeneic tumors

Spleen cells from syngeneic tumor-bearing mice were examined for direct cell-mediated cytotoxicity (DCMC) and lectin-dependent cell-mediated cytotoxicity (LDCC). In the DCMC assay specific cytotoxicity against the homologous tumor cell was assessed. In the LDCC assay cytotoxicity was nonspecifically assessed against EL-4 cells in the presence of concanavalin A or phytohemagglutinin. Most tumor lines tested (19/22) produced no cytotoxic reactivity in either the DCMC or LDCC assays. In the case of the remaining tumor lines (EL-4, BW5147-3, and P815 Y-3), significant LDCC, but not DCMC, was detected, which indicated that although cytotoxic effector cells had been activated, the reactivity was not directed toward the homologous tumor cell or could not be expressed in the DCMC assay. The EL-4 and BW5147-3 cell lines proved to be sporadic in terms of their ability to induce LDCC, whereas the P815 Y-3 cell line produced consistent LDCC. Reactivity induced by P815 Y-3 cells appeared to be due to the constitutive production and release of a soluble component which could activate cytotoxic T-cells in vivo.

Ventricular septal rupture after acute myocardial infarction: diagnosis by two-dimensional echocardiography

A 69-year-old woman had ventricular septal rupture after acute anterolateral myocardial infarction. The defect was demonstrated directly by two-dimensional echocardiography. The appearance of negative contrast in the right ventricle during systole and microbubbles traversing the defect from right to left during diastole further confirmed the rupture. Two-dimensional echocardiography also accurately characterized the nature and extent of associated myocardial damage.

Lectin-dependent cell-mediated cytotoxicity following in vitro culture of normal lymphocytes in medium containing 2-mercaptoethanol

Cell-mediated cytotoxic reactivity resulting from the in vitro incubation of normal lymphocytes was assessed using nonspecific lectin-dependent cell-mediated cytotoxicity (LDCC) as a measure of overall reactivity. Spleen cells from non-immune C57BL/6 mice were incubated in vitro in RPM1-1640 supplemented with 10% fetal calf serum and 2-mercaptoethanol (2ME). Cytotoxicity was assayed against syngeneic Cr51-labeled EL-4 cells in the presence of Con A or PHA. Optimal LDCC was observed after 8 days of culture in the presence of 5 X 10(-5) M 2ME. Cytotoxicity was mediated by an activated T-lymphocyte population whose development did not appear to require macrophages. Usually LDCC in the presence of PHA was significantly greater than that obtained in the presence of Con A. The presence of 2ME during the initial phase of culture was crucial for the development of cytotoxicity, since early removal of 2ME after 1 or 3 days of culture did not alter the subsequent development of cytotoxicity, whereas delayed addition of 2ME on day 1 or 3 failed to produce cytotoxic reactivity. This rapid conversion from a 2ME sensitive state to a 2ME insensitive state may be related to a rapid loss of accessory cell viability during the early phase of culture. Together the results indicate that this system may provide a useful model for the investigation of the events leading to the development of CTL in vitro.

Observer variation in the angiocardiographic diagnosis of mitral valve prolapse

The purpose of this study was to assess the reliability of the angiocardiographic diagnosis of mitral valve prolapse by measuring agreement between observers using defined diagnostic criteria. Sixty high-quality left ventriculograms, selected to include many that showed possible mitral valve prolapse, were reviewed by three angiocardiographers. Disagreement between observers as to positivity occurred in 26 percent and 30 percent of the cases on two reviews, and disagreement as to specific scallop involvement occurred in 68 percent and 78 percent of the cases. A specific observer agreed with himself in interpretation of positive 78 to 82 percent of the time and in the interpretation of specific scallop involvement 55 to 90 percent of the time. These results indicate that in the absence of generally agreed upon quantitative angiocardiographic criteria for the diagnosis of mitral valve prolapse, there is considerable variability among observers in the interpretation of mitral valve prolapse by angiocardiographic studies.

Effect of allogeneic challenge dose and cyclophosphamide treatment on the development of delayed-type hypersensitivity and cell-mediated cytotoxicity

Mice were challenged with high (10(8)) or low (10(4)) numbers of allogenic tumor cells and assessed for cellular immunity. The responses obtained indicated that high dose challenge produced both delayed-type hypersensitivity (DTH) and cell-mediated cytotoxic reactivity (DCMC), while low dose challenge produced DTH, an apparent suppressive effect, and little or no DCMC. Pretreatment with 100 mg/kg of cyclophosphamide (CTX) 3 d before antigen failed to alter this pattern, but treatment 3 d after antigen administration abrogated both DTH and DCMC. Animals given a combined modulating protocol consisting of an initial low dose challenge followed on day 3 by CTX treatment and day 6 by a high dose challenge developed DCMC in the presence of a greatly reduced or absent DTH response. These results demonstrate the differential effects of allogeneic challenge dose on the development of cellular immunity; the differential effects of CTX treatment given prior to or following alloimmunization, and demonstrate how these effects can be combined to modulate the immune response by selectively activating subpopulations of T-lymphocytes.

Pulmonary hemodynamics in systemic hypertension. Long-term effect of minoxidil

To assess the effect of minoxidil on pulmonary hemodynamics, we performed cardiac catheterization on ten patients, prior to the administration of minoxidil, at six months after its addition to their existing drug regimens, and on seven patients following 12 or more months of minoxidil therapy. Systemic blood pressure and systemic vascular resistance were significantly reduced at six months and following 12 or more months of minoxidil therapy. Before receiving minoxidil, nine of ten patients had elevated pulmonary vascular resistance. There were no significant changes in pulmonary vascular resistance following the initiation of minoxidil. The data suggest that pulmonary hypertension is common in patients with long-standing poorly controlled systemic hypertension, and that minoxidil, in doses sufficient to significantly reduce systemic blood pressure, does not cause or aggravate pulmonary hypertension.

Isolation and partial sequence of the cyanogen bromide peptides from calf thymus non-histone chromosomal protein HMG 1

Peptides produced by cyanogen bromide cleavage of non-histone chromosomal protein HMG 1 have been isolated and characterized, and their partial sequences determined. The sequence data presented here account for over half of the sequence of the HMG 1 molecule and, together with previously published results, provide interesting information on the charge distribution within the molecule.

The noninvasive cardiac evaluation of long-distance runners

Twelve long-distance runners were evaluated by physical examination, electrocardiogram, vectorcardiogram, chest x-ray film, and echocardiogram; and the results were compared to the findings in 12 normal control subjects. The athletes showed a significantly higher frequency of gallop rhythms with a third or fourth heart sound. Electrocardiographic and vectorcardiographic abnormalities consisting of right or left ventricular hypertrophy, bradycardia, and alterations in the ST-T wave were also present in the runners. Echocardiographic examination of the athletes revealed increased wall thickness, left ventricular muscular mass, diastolic volume, and ventricular function. It is essential that the physician who examines athletes be aware of the spectrum of apparently abnormal findings in this group. Echocardiographic studies should prove useful in establishing the presence or absence of some forms of cardiac disease in athletes.

Mitral regurgitation secondary to ruptured chordae tendineae: clinical, hemodynamic and electrocardiographic findings

The clinical, hemodynamic, and electrocardiographic findings in 11 patients with mitral regurgitation secondary to ruptured chordae tendineae are presented. Left atrial overloading, as manifested by a large terminal negative force in the P wave of lead V1, was present in 8 of the 11 patients. Six of the eight patients with this atrial abnormality had a normal size or minimally enlarged left atrium on chest x-ray films and angiography. Left ventricular hypertrohpy was present in 7 of the 11 patients and appeared to be related to the duration of cardiac symptoms. It is concluded that a large terminal negative force in the P wave in lead V1 is a useful clinical indicator of increased left atrial pressure in mitral regurgitation of recent onset. The electrocardiographic finding of left atrial overloading is to be expected in most cases of mitral regurgitation secondary to rupture of the chordae tendineae.