Improved survival in COVID-19 related sepsis and ARDS treated with a unique "triple therapy" including therapeutic plasma exchange: A single center retrospective analysis

BACKGROUND

Throughout the COVID-19 pandemic, the mortality of critically ill patients remained high. Our group developed a treatment regimen targeting sepsis and ARDS which we labeled "triple therapy" consisting of (1) corticosteroids, (2) therapeutic plasma exchange (TPE), and (3) timely intubation with lung protective ventilation. Our propensity analysis assesses the impact of triple therapy on survival in COVID-19 patients with sepsis and ARDS.

METHODS

Retrospective propensity analysis comparing triple therapy to no triple therapy in adult critically ill COVID-19 patients admitted to the Intensive Care Unit at Lexington Medical Center from 1 March 2020 through 31 October 2021.

RESULTS

Eight hundred and fifty-one patients were admitted with COVID-19 and 53 clinical and laboratory variables were analyzed. Multivariable analysis revealed that triple therapy was associated with increased survival (OR: 1.91; P = .008). Two propensity score-adjusted models demonstrated an increased likelihood of survival in patients receiving triple therapy. Patients with thrombocytopenia were among those most likely to experience increased survival if they received early triple therapy. Decreased survival was observed with endotracheal intubation ≥7 days from hospital admission (P < .001) and there was a trend toward decreased survival if TPE was initiated ≥6 days from hospital admission (P = .091).

CONCLUSION

Our analysis shows that early triple therapy, defined as high-dose methylprednisolone, TPE, and timely invasive mechanical ventilation within the first 96 hours of admission, may improve survival in critically ill septic patients with ARDS secondary to COVID-19 infection. Further studies are needed to define specific phenotypes and characteristics that will identify those patients most likely to benefit.

Influence of therapeutic plasma exchange treatment on short-term mortality of critically ill adult patients with sepsis-induced organ dysfunction: a systematic review and meta-analysis

INTRODUCTION

The impact of therapeutic plasma exchange (TPE) on short-term mortality in adult patients with sepsis-induced organ dysfunction remains uncertain. The objective of the study is to assess the effect of adjunct TPE in this setting through a comprehensive literature review.

METHODS

The National Library of Medicine's Medline, Ovid (Embase), the Cochrane Library database and clinicaltrial.gov from January 01, 1966, until October 01, 2022, were searched for terms: therapeutic plasma exchange, plasmapheresis, sepsis, and septic shock. We reviewed, selected and extracted data from relevant randomized clinical trials (RCTs) and matched cohort studies (MCSs) comparing short-term mortality in critically ill adult septic patients treated with standard therapy versus those receiving adjunct TPE. Risk of bias was assessed in the RCTs using Cochrane Collaboration tool and in MCSs using ROBINS-I tool. Summary statistics, risk ratios (RRs), and confidence intervals (CIs) were calculated using random effects model.

RESULTS

This systematic review included 937 adult critically ill septic patients from five RCTs (n = 367) and fifteen MCSs (n = 570). Of these total, 543 received treatment with TPE in addition to standard care. The meta-analysis includes all five RCTs and only six MCSs (n = 627). The adjunct TPE treatment (n = 300) showed a significant reduction in short-term mortality (RR 0.59, 95% CI 0.47-0.74, I2 3%) compared to standard therapy alone (n = 327). The systematic review of all 20 trials revealed that adding TPE to the standard therapy of critically ill septic patients resulted in faster clinical and/or laboratory recovery.

CONCLUSIONS

Our comprehensive and up-to-date review demonstrates that adjunct TPE may provide potential survival benefits when compared to standard care for critically ill adult patients with sepsis-induced organ dysfunction. While results of this meta-analysis are encouraging, large well-designed randomized trials are required to identify the optimal patient population and TPE procedure characteristics prior to widespread adoption into practice.

Penetrating thoracic injury requiring emergency pneumonectomy supported with two ECMO runs: A testament to multidisciplinary critical care medicine

Post-traumatic pneumonectomies are uncommon and, if necessary, carry significant mortality. The use of extracorporeal membrane oxygenation (ECMO) for lung injury in trauma patient has demonstrated efficacy with minimal bleeding complications. We report a case of a young man with a penetrating thoracic injury that required a pneumonectomy supported with two separate ECMO runs for pulmonary failure postoperatively.

High-Frequency Oscillatory Ventilation for Refractory Hypoxemia in Severe COVID-19 Pneumonia: A Small Case Series

Case series

Patients: Female, 21-year-old • Female, 53-year-old • Male, 38-year-old

Final Diagnosis: ARDS • COVID pneumonia

Symptoms: Respiratory failure • sepsis • shock

Medication: —

Clinical Procedure: High-frequency oscillatory ventilation (HFOV) • mechanical ventilation • oscillator

Specialty: Critical Care Medicine

Unprovoked serotonin syndrome-like presentation of SARS-CoV-2 infection: A small case series

Clinicians and researchers have reported an array of neurological abnormalities in coronavirus disease 2019 (COVID-19), and while serotonin excess has been observed we are unaware of reports of central nervous system serotonin toxicity in COVID-19. We present two cases that resemble serotonin syndrome in COVID-19, but without identifiable inciting medications. A 54-year-old with multiple sclerosis and diabetes mellitus presented with altered mental status. His altered sensorium was attributed to diabetic ketoacidosis, but his condition quickly deteriorated with fever to 105 degrees Fahrenheit, rigidity in all extremities, inducible clonus, and hyperreflexia. He was intubated and was treated for possible meningitis and seizure. Neurologic workup was negative for acute pathology. Despite acetaminophen, his core temperature remained elevated to 105 degrees Fahrenheit. He was treated with external cooling and cyproheptadine and within 48 h, his fever, rigidity, hyperreflexia, and clonus resolved. He was extubated and discharged home on day 14. A 72-year-old with hyperlipidemia was admitted with tremors, 4 days after testing positive for COVID-19. His symptoms rapidly worsened, and he was transferred to the Intensive Care Unit on day 3 in extremis, febrile to 104.4 degrees Fahrenheit, heart rate of 180 beats per minute, and apparent whole body myoclonus. He was intubated and developed fever refractory to acetaminophen requiring external cooling. Extensive neurologic workup was negative. He received cyproheptadine and slowly improved. He was extubated and discharged to rehab on day 11. These cases represent a unique presentation in COVID-19 that must be considered and requires a high index of suspicion.

The therapeutic efficacy of adjunct therapeutic plasma exchange for septic shock with multiple organ failure: a single-center experience

Background

Sepsis remains a common condition with high mortality when multiple organ failure develops. The evidence for therapeutic plasma exchange (TPE) in this setting is promising but inconclusive. Our study aims to evaluate the efficacy of adjunct TPE for septic shock with multiple organ failure compared to standard therapy alone.

Methods

A retrospective, observational chart review was performed, evaluating outcomes of patients with catecholamine-resistant septic shock and multiple organ failure in intensive care units at a tertiary care hospital in Winston-Salem, NC, from August 2015 to March 2019. Adult patients with catecholamine-resistant septic shock (≥ 2 vasopressors) and evidence of multiple organ failure were included. Patients who received adjunct TPE were identified and compared to patients who received standard care alone. A propensity score using age, gender, chronic co-morbidities (HTN, DM, CKD, COPD), APACHE II score, SOFA score, lactate level, and number of vasopressors was used to match patients, resulting in 40 patients in each arm.

Results

The mean baseline APACHE II and SOFA scores were 32.5 and 14.3 in TPE patients versus 32.7 and 13.8 in control patients, respectively. The 28-day mortality rate was 40% in the TPE group versus 65% in the standard care group (p = 0.043). Improvements in baseline SOFA scores at 48 h were greater in the TPE group compared to standard care alone (p = 0.001), and patients receiving adjunct TPE had a more favorable fluid balance at 48 h (p = 0.01). Patients receiving adjunct TPE had longer ICU and hospital lengths of stay (p = 0.003 and p = 0.006, respectively).

Conclusions

Our retrospective, observational study in adult patients with septic shock and multiple organ failure demonstrated improved 28-day survival with adjunct TPE compared to standard care alone. Hemodynamics, organ dysfunction, and fluid balance all improved with adjunct TPE, while lengths of stay were increased in survivors. The study design does not allow for a generalized statement of support for TPE in all cases of sepsis with multiple organ failure but offers valuable information for a prospective, randomized clinical trial.

The successful use of therapeutic plasma exchange for severe COVID-19 acute respiratory distress syndrome with multiple organ failure

The COVID-19 pandemic has brought about an urgent need for effective treatment, while conserving vital resources such as intensive care unit beds and ventilators. Antivirals, convalescent plasma, and biologics have been used with mixed results. The profound "cytokine storm" induced endotheliopathy and microthrombotic disease in patients with COVID-19 may lead to acute respiratory distress syndrome, sepsis, and multi-organ failure. We present a case of SARS-COV2 pneumonia with septic shock and multi-organ failure that demonstrated significant clinical improvement after therapeutic plasma exchange. A 65-year-old female with multiple comorbidities presented with progressive dyspnea and dry cough. She was found to be COVID-19 positive with pneumonia, and developed progressive hypoxemia and shock requiring vasopressors, cardioversion, and non-invasive positive pressure ventilation. Given her worsening sepsis with multi-organ failure, she underwent therapeutic plasma exchange with rapid clinical improvement. Her case supports the theory that plasma exchange may help abate the "cytokine storm" induced endotheliopathy and microthrombosis associated with COVID-19. Further studies are needed to identify markers of this pathway and the potential role of plasma exchange in these critically ill patients.

Variations in the cerebrospinal fluid proteome following traumatic brain injury and subarachnoid hemorrhage

BACKGROUND

Proteomic analysis of cerebrospinal fluid (CSF) has shown great promise in identifying potential markers of injury in neurodegenerative diseases [1-13]. Here we compared CSF proteomes in healthy individuals, with patients diagnosed with traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) in order to characterize molecular biomarkers which might identify these different clinical states and describe different molecular mechanisms active in each disease state.

METHODS

Patients presenting to the Neurosurgery service at the Louisiana State University Hospital-Shreveport with an admitting diagnosis of TBI or SAH were prospectively enrolled. Patients undergoing CSF sampling for diagnostic procedures were also enrolled as controls. CSF aliquots were subjected to 2-dimensional gel electrophoresis (2D GE) and spot percentage densities analyzed. Increased or decreased spot expression (compared to controls) was defined in terms of in spot percentages, with spots showing consistent expression change across TBI or SAH specimens being followed up by Matrix-Assisted Laser Desorption/Ionization mass spectrometry (MALDI-MS). Polypeptide masses generated were matched to known standards using a search of the NCBI and/or GenPept databases for protein matches. Eight hundred fifteen separately identifiable polypeptide migration spots were identified on 2D GE gels. MALDI-MS successfully identified 13 of 22 selected 2D GE spots as recognizable polypeptides.

RESULTS

Statistically significant changes were noted in the expression of fibrinogen, carbonic anhydrase-I (CA-I), peroxiredoxin-2 (Prx-2), both α and β chains of hemoglobin, serotransferrin (Tf) and N-terminal haptoglobin (Hp) in TBI and SAH specimens, as compared to controls. The greatest mean fold change among all specimens was seen in CA-I and Hp at 30.7 and -25.7, respectively. TBI specimens trended toward greater mean increases in CA-I and Prx-2 and greater mean decreases in Hp and Tf.

CONCLUSIONS

Consistent CSF elevation of CA-I and Prx-2 with concurrent depletion of Hp and Tf may represent a useful combination of biomarkers for the prediction of severity and prognosis following brain injury.

Early enteral feedings in adults receiving venovenous extracorporeal membrane oxygenation

INTRODUCTION

For over 20 years extracorporeal membrane oxygenation (ECMO) has been an advanced treatment for adults, children and neonates with severe respiratory failure that has failed to respond or improve with conventional therapy. Withholding enteral feeding in patients on ECMO is common practice in many centers, based partly on the risk of splanchnic ischemia resulting in loss of intestinal integrity, predisposing to bacterial translocation and sepsis. We report one center's experience with early enteral nutrition in adult patients receiving venovenous (VV) ECMO for severe respiratory failure.

METHODS

Adult patients that received VV ECMO at LSUHSC-Shreveport over the last 8 years were eligible for inclusion.

RESULTS

A total of 27 patients met these criteria and their charts and nutrition therapy reviewed. Average duration of ECMO support was 8.7 +/- 3.6 days. Twenty-six of 27 (96%) received enteral nutrition via gastric tube alone or in combination with total parenteral nutrition (TPN). Eighteen patients received enteral nutrition as their only source of nutritional supplementation, with the remainder receiving partial nutrition support via the parenteral route. Seventy-five percent of the patients received prokinetic medication within the first 24 hours, with 95% receiving prokinetic therapy by 48 hours. No patients developed intestinal ischemia, gastrointestinal bleeding, or other complications related to early enteral feeding.

CONCLUSION

Enteral nutrition started within the first 24 to 36 hours of initiating venovenous ECMO support is safe and well-tolerated in adults. No serious adverse events were attributable to enteral nutrition in these patients.

Clinical case of the month. Idiopathic pulmonary hemosiderosis presenting as a rare cause of iron deficiency anemia in a toddler--a diagnostic challenge

Iron deficiency anemia is the most common cause of anemia in all age groups. Idiopathic pulmonary hemosiderosis is an extremely rare etiology of iron deficiency anemia seen predominantly in the pediatric population. Idiopathic pulmonary hemosiderosis is characterized by the triad of symptoms consisting of iron deficiency anemia, diffuse pulmonary infiltrates, and hemoptysis. The clinical presentation is extremely variable, and all three symptoms may not always be seen. Due to the rarity of the disease and the variability in clinical presentation, diagnosis is usually delayed. Early diagnosis and treatment with corticosteroids prevents further episodes of recurrent alveolar hemorrhage and improves the clinical outcome. Hence, a high index of suspicion is required for the diagnosis of this condition in young patients presenting with severe iron deficiency anemia and diffuse pulmonary infiltrates. We report a toddler with idiopathic pulmonary hemosiderosis whose initial clinical presentation was severe iron deficiency anemia.

Pumpless arteriovenous carbon dioxide removal: A novel simplified strategy for severe asthma in children

Status asthmaticus unresponsive to pharmacotherapy is conventionally managed with mechanical ventilation, which has its inherent challenges due to barotrauma, dynamic hyperinflation and autopositive end-expiratory pressure (auto-PEEP). Extracorporeal membrane oxygenation has been used as a last resort in respiratory failure due to refractory asthma; however, it entails many complications. In contrast, arteriovenous carbon dioxide removal (AVCO₂R) is a novel strategy that has been shown to be highly effective in adults with acute respiratory failure. Only one pediatric case series of pediatric asthma managed with AVCO₂R have been published so far. We herein report a case of severe asthma in a 9-year-old boy who developed severe hypercapnia (Pco2 97 mmHg) and acidosis (pH 7.09) despite being on mechanical ventilation. Within 4 h of initiation of AVCO₂R, PCo₂ drastically reduced to near-normal levels. He was discharged on day 9 of hospital stay without any complications.

Angiopoietins as promising biomarkers and potential therapeutic targets in brain injury

Traumatic brain injury (TBI) and sub-arachnoid hemorrhage (SAH) are major causes of long-term disability, mortality, and enormous economic costs to society. The full spectrum of neurological damage created by TBI or SAH is not usually manifested at the time of injury, but evolves gradually over the course of hours to days (or weeks) following these injuries. Angiopoietins, important regulators of vascular structure and function, are hallmark indicators of vascular injury and may therefore represent promising targets in the treatment of SAH and TBI. In animal models and human tissues, normal intracerebral and pial vessels show strong expression of Angiopoietin-1 (Ang-1), but only minimal expression or presentation of Angiopoietin-2 (Ang-2). After several types of neurotrauma, the ratios of Ang-1 and Ang-2 expression in brain microvessel are disturbed and appear to contribute to the remarkable loss of blood-brain barrier (BBB) in these injuries. Angiopoietins levels, and perhaps more importantly, Angiopoietin ratios (1:2) may have novel and important diagnostic and prognostic uses in TBI and SAH brain injury. Ang-1/2 evaluation in plasma, serum and cerebrospinal fluid may provide new therapeutic modalities which can modify 'secondary' forms of brain injury after TBI and SAH.

Yield and characterization of subcutaneous human adipose-derived stem cells by flow cytometric and adipogenic mRNA analyzes

BACKGROUND AIMS

Adipose-derived stromal/stem cells (ASC) capable of multipotential differentiation can be isolated with high yields from human subcutaneous lipoaspirates. This study reports our recent experience of isolating and immunophenotypically characterizing ASC from >60 human patients with a mean age of 43.6 and body mass index (BMI) of 27.

METHODS

We examined the ASC yield per unit volume of lipoaspirate tissue, the surface antigen profile based on flow cytometry, histochemical differentiation potential along the adipogenic and osteogenic pathways, and expression of adipogenic mRNA by transcriptomic microarray and reverse transcription (RT)-polymerase chain reaction (PCR).

RESULTS

The population (n = 64) of predominantly Caucasian (84.3%) female (90.6%) donors had a mean age of 43.6 +/- 11.1 years and a mean BMI of 27.0 +/- 3.8. A yield of 375 +/- 142 x 10(3) ASC was obtained per milliliter of lipoaspirate within a 4.1 +/- 0.7-day culture period (n = 62). The ASC population was uniformly CD29(+) CD34(+) CD44(lo) CD45(lo) CD73(+) CD90(+) CD105(+) and capable of undergoing both adipogenesis and osteogenesis in vitro based on Oil Red O and Alizarin Red staining, respectively. Adipogenic differentiation was associated with a significant induction of multiple mRNA associated with lipid storage and synthesis based on microarray analysis of n = 3 donors. During an adipogenic differentiation time-course, representative mRNA (adiponectin, C/EBPalpha, leptin and LPL) displayed increases of several orders of magnitude.

CONCLUSIONS

These findings demonstrate the reproducibility of subcutaneous lipoaspirates as a consistent and abundant source of functional ASC from donors across a spectrum of ages and BMI. These results have relevance for regenerative medical applications exploiting autologous and allogeneic ASC for soft and hard tissue engineering.

Diabetic ketoacidosis preceding thrombocytopenia associated multiple organ failure in a child

CONTEXT

Thrombocytopenia associated multiple organ failure is a rare but increasingly recognized condition in children. Diabetic ketoacidosis preceding thrombocytopenia associated multiple organ failure is previously unreported in pediatric patients.

CASE REPORT

A 12-year-old female presented with diabetic ketoacidosis along with acute pancreatitis. She further developed thrombocytopenia and renal failure over the next two days. Although hemolytic uremic syndrome/thrombotic thrombocytopenic purpura spectrum was considered, the clinical picture seemed most consistent with thrombocytopenia associated multiple organ failure. The patient was treated with serial therapeutic plasma exchanges and made a complete recovery.

CONCLUSION

A high index of suspicion of thrombocytopenia associated multiple organ failure is required in patients with diabetic ketoacidosis or pancreatitis who present with thrombocytopenia and renal failure. Plasma exchange is a life-saving intervention in such cases.

Agitation and/or aggression after traumatic brain injury in the pediatric population treated with ziprasidone. Clinical article

OBJECT

Agitation and aggression are common after traumatic brain injury (TBI) and can hamper recovery and rehabilitative efforts. To date, there is no consensus on pharmaceutical intervention for these conditions after TBI. Ziprasidone has been reported efficacious in this population but the evidence is limited. The authors report their experience of using ziprasidone to treat posttraumatic brain injury agitation in 20 consecutive pediatric patients. A secondary objective of this case series was to attempt to establish an age-specific dosage and identify possible side effects of this medication.

METHODS

This case series study was performed at a university hospital and pediatric trauma center. Over an 18-month period, all patients who presented to the pediatric intensive care unit with TBI and later developed agitation and/or aggression were treated with ziprasidone as the sole intervention. Pre- and posttreatment scores on the Riker Sedation-Agitation Scale (SAS) were recorded along with demographic data.

RESULTS

Twenty children received ziprasidone for agitation and/or aggression during the immediate recovery period from TBI. The median patient age was 8 years (range 9 months-17 years). Children were stratified into 4 age groups: <2 years old (Group 1), 2-6 years old (Group 2), 7-12 years old (Group 3), and >or=13 years old (Group 4). The SAS score, before and 24 hours after the initiation of ziprasidone, demonstrated a significant reduction after initiation of the medication (p<0.001). The initial dose for Groups 1-4 was 1.7, 0.9, 0.7, and 0.6 mg/kg, respectively, with final doses of 1.8, 1.5, 1.7, and 0.07 mg/kg, respectively. The duration of therapy for Groups 1-4 was 5, 8, 6, and 3 days, respectively. All patients received continuous cardiac and blood-pressure monitoring. No adverse events were reported in any of the age groups.

CONCLUSIONS

Based on this limited patient series, ziprasidone appears to be safe and effective in pediatric patients with closed head injuries who develop agitation and/or aggression in the immediate postinjury period. Ziprasidone consistently lowered SAS scores and did so in all age groups. There were minimal dose adjustments and the duration of therapy was relatively brief. No adverse events were reported. A prospective trial of ziprasidone in this population appears warranted.

Signet-ring-cell adenocarcinoma of the myocardium presenting as persistent pleural effusions

We report a case of persistent bilateral pleural effusions in a 40-year-old man with echocardiographic findings suggesting constrictive pericarditis. However, this was not supported by cardiac catheterization. The pleural fluid was transudative in nature and was negative for acid-fast bacilli (AFB) and malignancy. Radiographic studies did not define an underlying etiology. Filling defects were found in the subclavian and jugular veins bilaterally but no pulmonary embolus was found on computed tomographic (CT) scan. The patient developed sudden and profound hypoxia and subsequent pulseless electrical activity and expired. At autopsy the myocardium, pericardium, and proximal blood vessels were invaded with signet-ring-cell adenocarcinoma. Another focus of this tumor also was found in the spleen but not in the stomach, suggesting the heart may have been primary. If so, this is the first reported case of primary cardiac signet-ring-cell adenocarcinoma.

Near-fatal pediatric asthma managed with pumpless arteriovenous carbon dioxide removal

OBJECTIVE

To describe the use of pumpless arteriovenous carbon dioxide removal in support of four pediatric patients with near-fatal asthma.

DESIGN

Report of four cases.

SETTING

Tertiary care university pediatric intensive care unit.

PATIENTS

Four pediatric patients, ages 4, 10, 12, and 13, were intubated and initially managed with positive pressure ventilation for severe respiratory failure. Despite pharmacologic therapy with inhaled beta-agonists, inhaled anticholinergics, systemic corticosteroids, and intravenous magnesium, marked progressive hypercapnia and acidosis rapidly developed requiring high levels of positive pressure ventilation.

INTERVENTIONS

Application of pumpless arteriovenous carbon dioxide removal (AVCO2R) via percutaneous femoral cannulation.

MEASUREMENT AND MAIN RESULTS

Arterial or mixed venous carbon dioxide partial pressure (PCO2) and pH were measured before and at intervals following initiation of AVCO2R. Before cannulation, PCO2 was elevated to 100, 108, 90, and 186 mm Hg in the four patients, with corresponding pH of 7.07, 6.96, 7.09, and 6.80, respectively. Pco2 levels were reduced to more acceptable levels (37-57 mm Hg) within 2-4 hrs of initiation of AVCO2R, with corresponding improvements in pH despite reductions in ventilatory frequency and tidal volumes to safe levels. Duration of support ranged from 18 hrs to 5 days during resolution of bronchospasm. No red blood cell or platelet transfusions were required, and no complications resulted from AVCO2R or from mechanical ventilation. All patients were discharged from the hospital without sequelae.

CONCLUSIONS

Percutaneous cannulation with a simplified pumpless extracorporeal circuit is capable of removing sufficient carbon dioxide to allow application of a protective ventilatory strategy in severe hypercapnic pediatric respiratory failure. The procedure was safely applied without complications in four pediatric patients as young as 4 yrs of age.

Circadian oscillation of gene expression in murine calvarial bone

The genes encoding the core circadian transcription factors display an oscillating expression profile in murine calvarial bone. More than 26% of the calvarial bone transcriptome exhibits a circadian rhythm, comparable with that observed in brown and white adipose tissues and liver. Thus, circadian mechanisms may directly modulate oxidative phosphorylation and multiple metabolic pathways in bone homeostasis.

INTRODUCTION

Although circadian rhythms have been associated historically with central regulatory mechanisms, there is emerging evidence that the circadian transcriptional apparatus exists in peripheral tissues. The aim of this study was to determine the presence and extent of circadian oscillation in the transcriptome of murine calvarial bone.

MATERIALS AND METHODS

Cohorts of 8-week-old male AKR/J mice were maintained in a controlled 12-h light:12-h dark cycle on an ad libitum diet for 2 weeks. Groups of three mice were killed every 4 h over a 48-h period. The level of gene expression at successive times-points was determined by quantitative RT-PCR and Affymetrix microarray. Data were analyzed using multiple statistical time series algorithms, including Cosinor, Fisher g-test, and the permutation time test.

RESULTS

Both the positive (Bmal1, Npas2) and negative (Cry1, Cry2, Per1, Per2, Per3) elements of the circadian transcriptional apparatus and their immediate downstream targets and mediators (Dbp, Rev-erbalpha, Rev-erbbeta) exhibited oscillatory expression profiles. Consistent with findings in other tissues, the positive and negative elements were in antiphase relative to each other. More than 26% of the genes present on the microarray displayed an oscillatory profile in calvarial bone, comparable with the levels observed in brown and white adipose tissues and liver; however, only a subset of 174 oscillating genes were shared among all four tissues.

CONCLUSIONS

Our findings show that the components of the circadian transcriptional apparatus are represented in calvarial bone and display coordinated oscillatory behavior. However, these are not the only genes to display an oscillatory expression profile, which is seen in multiple pathways involving oxidative phosphorylation and lipid, protein, and carbohydrate metabolism.

Glucocorticoids inhibit the cerebral microvascular dysfunction associated with sepsis in obese mice

OBJECTIVES

Obesity is associated with increased morbidity and mortality in critically ill patients. It is unclear whether this increase is due to exaggerated inflammatory response alone or due to lack of response to therapeutic agents used. The objective of this study was to determine whether low-dose steroid therapy, which has proven effective in clinical setting, affords any benefit in the increased morbidity to sepsis in genetically obese (ob/ob) mice.

METHODS

Intravital videomicroscopy was used to monitor and quantify the adhesion of platelets and leukocytes in the brain microcirculation of lean (WT) and ob/ob mice subjected to cecal ligation and puncture (CLP) with or without dexamethasone 4 mg/kg within 15 min of surgery. The dual radiolabeled monoclonal antibody method was used to measure P-selectin expression in the microcirculation, while the sepsis-induced behavioral deficit was quantified using a multicompartment chamber test.

RESULTS

Dexamethasone completely prevented the accumulation of adherent leukocytes and platelets observed at 4 h after CLP in both WT and ob/ob mice. The steroid also prevented the CLP-induced upregulation of P-selectin in the brain and other vascular beds, and it attenuated the behavioral deficit in ob/ob, but not in lean, mice.

CONCLUSION

Low-dose glucocorticoid therapy is beneficial in experimental sepsis in obese animals compared to lean animals.

Heparin-induced thrombocytopenia in a pediatric patient receiving extracorporeal membrane oxygenation managed with argatroban

INTRODUCTION

Heparin-induced thrombocytopenia (HIT) is rare in the pediatric population, with a majority occurring in the pediatric intensive care unit setting. All cases reported to date have been associated with the use of unfractionated heparin. Because unfractionated heparin is the anticoagulant of choice for extracorporeal membrane oxygenation (ECMO) and other extracorporeal therapies, the development of HIT in these patients can be devastating, making management problematic. We report a case of HIT type II with evidence of small-vessel arterial thrombosis in a 17-month-old boy receiving ECMO and continuous renal replacement therapy successfully treated with argatroban.

CASE

The patient was a 17-month-old boy with severe hypercapnic and hypoxemic respiratory failure secondary to asthma and mucus plugging that failed conventional and unconventional ventilation. Venovenous ECMO was initiated, and within 24 hrs, there was a precipitous decrease in the platelet count, with the development of cutaneous ischemia involving his lower limbs. Argatroban was started and the child maintained on ECMO and continuous renal replacement therapy, with resolution of the cutaneous ischemia and recovery of the platelet count. Heparin-associated antibodies were positive.

DISCUSSION

HIT is rare in the pediatric population. Recognition of HIT is vital because withdrawal of heparin is the first and most important therapy. For patients receiving ECMO or continuous renal replacement therapy who develop HIT, synthetic thrombin inhibitors have been reported as an alternative. However, little information on their use in extracorporeal life support has been published, particularly in the pediatric population.

CONCLUSION

This report documents a pediatric case of HIT type II successfully treated with argatroban, allowing continuation of the ECMO and continuous renal replacement therapy therapy, with resolution of the cutaneous ischemia and thrombocytopenia.

Heparin-induced thrombocytopenia in a pediatric patient receiving extracorporeal support and treated with argatroban

INTRODUCTION

Heparin-induced thrombocytopenia (HIT) is rare in the pediatric population, with a majority occurring in the pediatric intensive care unit setting. All reported cases have been associated with the use of unfractionated heparin. Because unfractionated heparin is the anticoagulant of choice for extracorporeal life support, the development of HIT in these patients can be devastating. We report a case of HIT with evidence of small-vessel arterial thromboembolism in a 17-month-old child receiving extracorporeal membrane oxygenation and continuous renal replacement therapy successfully treated with argatroban.

CASE

The patient was a 17-month-old boy with severe respiratory failure secondary to asthma and mucus plugging that failed conventional and unconventional ventilation. Venovenous extracorporeal membrane oxygenation was initiated, and within 24 hrs, there was a precipitous decrease in the platelet count, with the development of cutaneous ischemia involving his lower limbs. Heparin-associated antibodies were positive. Argatroban was started, and the child maintained on extracorporeal membrane oxygenation and continuous renal replacement therapy, with resolution of the cutaneous ischemia and rebound of the thrombocytopenia.

DISCUSSION

HIT is rare in the pediatric population. Recognition of HIT is vital because withdrawal of heparin is the first and most important therapy. For patients on extracorporeal membrane oxygenation or continuous renal replacement therapy who develop HIT, synthetic thrombin inhibitors (hirulogs) have been reported as an alternative. However, little information on their use in extracorporeal life support has been published, particularly in the pediatric population.

CONCLUSION

This report documents a pediatric case of HIT successfully treated with argatroban, allowing continuation of the venovenous extracorporeal membrane oxygenation and continuous renal replacement therapy, with resolution of the thromboembolic ischemia and thrombocytopenia.

Characterization of peripheral circadian clocks in adipose tissues

First described in the suprachiasmatic nucleus, circadian clocks have since been found in several peripheral tissues. Although obesity has been associated with dysregulated circadian expression profiles of leptin, adiponectin, and other fat-derived cytokines, there have been no comprehensive analyses of the circadian clock machinery in adipose depots. In this study, we show robust and coordinated expression of circadian oscillator genes (Npas2, Bmal1, Per1-3, and Cry1-2) and clock-controlled downstream genes (Rev-erb alpha, Rev-erb beta, Dbp, E4bp4, Stra13, and Id2) in murine brown, inguinal, and epididymal (BAT, iWAT, and eWAT) adipose tissues. These results correlated with respective gene expression in liver and the serum markers of circadian function. Through Affymetrix microarray analysis, we identified 650 genes that shared circadian expression profiles in BAT, iWAT, and liver. Furthermore, we have demonstrated that temporally restricted feeding causes a coordinated phase-shift in circadian expression of the major oscillator genes and their downstream targets in adipose tissues. The presence of circadian oscillator genes in fat has significant metabolic implications, and their characterization may have potential therapeutic relevance with respect to the pathogenesis and treatment of diseases such as obesity, type 2 diabetes, and the metabolic syndrome.

Circadian clocks are resounding in peripheral tissues

Circadian rhythms are prevalent in most organisms. Even the smallest disturbances in the orchestration of circadian gene expression patterns among different tissues can result in functional asynchrony, at the organism level, and may to contribute to a wide range of physiologic disorders. It has been reported that as many as 5%–10% of transcribed genes in peripheral tissues follow a circadian expression pattern. We have conducted a comprehensive study of circadian gene expression on a large dataset representing three different peripheral tissues. The data have been produced in a large-scale microarray experiment covering replicate daily cycles in murine white and brown adipose tissues as well as in liver. We have applied three alternative algorithmic approaches to identify circadian oscillation in time series expression profiles. Analyses of our own data indicate that the expression of at least 7% to 21% of active genes in mouse liver, and in white and brown adipose tissues follow a daily oscillatory pattern. Indeed, analysis of data from other laboratories suggests that the percentage of genes with an oscillatory pattern may approach 50% in the liver. For the rest of the genes, oscillation appears to be obscured by stochastic noise. Our phase classification and computer simulation studies based on multiple datasets indicate no detectable boundary between oscillating and non-oscillating fractions of genes. We conclude that greater attention should be given to the potential influence of circadian mechanisms on any biological pathway related to metabolism and obesity.

The metabolism of living organisms changes over the twenty-four hour daily cycle in an oscillatory manner. This repeating pattern of “peak” and “trough” expression is known as a “circadian rhythm.” We now know that the body's internal clock is controlled by a discrete group of genes. These important regulators are found in many different organs of the body, and they control expression of many other genes in the body. Using mice as an experimental animal, Ptitsyn and colleagues looked at the overall pattern of gene expression in fat tissues and the liver using three different mathematical tests. They present data indicating that the majority of active genes fluctuate rhythmically over a twenty-four hour period. This work suggests that future studies should pay close attention to the influence of the circadian rhythm in obesity and in fat metabolism.

Protective effects of low respiratory frequency in experimental ventilator-associated lung injury*

OBJECTIVE

To determine whether ventilator-associated lung hyperinflation injury can be attenuated by a reduction in respiratory frequency.

DESIGN

Prospective comparative laboratory investigation.

SETTING

University medical center research laboratory.

SUBJECTS

Male Sprague-Dawley rats.

INTERVENTIONS

Eight groups of isolated, perfused rat lungs were exposed to cyclic ventilation at different respiratory frequencies and tidal volumes. Each group of six to eight lung preparations was assigned to one of four respiratory frequencies (10, 20, 40, or 80 breaths/min) and one of two tidal volumes (5 or 20 mL.kg). Measurement of capillary filtration coefficient (Kf,c), a sensitive index of lung microvascular permeability and injury, was made at baseline and at 30, 60, and 90 mins of the experimental conditions.

MEASUREMENTS AND MAIN RESULTS

Lungs exposed to 5 mL.kg tidal volume had no elevation in Kf,c at any time point regardless of respiratory frequency. Lungs exposed to 20 mL. kg tidal volume and a respiratory frequency of 80 had significant elevations in Kf,c at all times after baseline compared with lungs exposed to respiratory frequencies of 10, 20, or 40 (0.14 +/- 0.03, 0.16 +/- 0.02, 0.31 +/- 0.05 vs. 0.76 +/- 0.16). Furthermore, the Kf,c at 90 mins was significantly higher than permeability at baseline in this group (1.53 +/- 0.45 vs. 0.12 +/- 0.02 mL.min.cm H2O.100 g of lung tissue).

CONCLUSIONS

Reduction in respiratory frequency to values much lower than normal ameliorated experimental ventilator-induced hyperinflation lung injury as determined by pulmonary capillary filtration coefficient.

Brain RNA expression in obese vs lean mice after LPS-induced systemic inflammation

Mortality of obese patients with severe sepsis is higher than non-obese patients. Thus far, a pathophysiologic mechanism has not been identified that explains this higher mortality. The central nervous system is now becoming increasingly recognized as a target organ in sepsis and the systemic inflammatory response syndrome and may hold clues to the deleterious affects of obesity in patients with sepsis syndrome. In this study, obese and non-obese mice were given LPS IP and the brains were harvested 2 hours after injection. The brains were processed and mRNA isolated and hybridized to a microarray chip and processed. Analysis of gene expression demonstrated distinct expression difference between the lean and obese animals. Ontology data supports clear differences between the lean and obese groups in the coagulation system, neuro-endocrine system, lipid transport and insulin receptors. Approximately eighty genes were identified to show 10-fold differential expression between the obese and lean mice.

Sepsis associated encephalopathy (SAE): a review

Sepsis associated encephalopathy (SAE) is a poorly understood condition that is associated with severe sepsis and appears to have a negative influence on survival. The incidence of encephalopathy secondary to sepsis is unknown. Amino acid derangements, blood-brain barrier disruption, abnormal neurotransmitters, and direct CNS effect are possible causes of septic encephalopathy. Research has not defined the pathogenesis of SAE.

Extracorporeal carbon dioxide removal to control arterial pH and PACO2 in a heart-beating donor with acute lung injury

BACKGROUND

Arteriovenous carbon dioxide (AVCO2R) removal is a technique of pumpless extracorporeal carbon dioxide removal. This system has been used successively to control pH and PaCO2 in patients with acute lung injury who could not be adequately ventilated. This report describes the use of this technology in an organ donor awaiting harvesting.

METHODS

AVCO2R was implanted using a hollow-fiber oxygenator attached to 12 F and 14 F vascular cannulas that were inserted into the femoral artery and vein, respectively. Oxygen was attached to the oxygenator to provide the sweep gas.

RESULTS

The PaCO2 and arterial pH promptly corrected after support was initiated (from 83-42 mm Hg and 7.18-7.38, respectively).

CONCLUSION

This case describes the successful use of pumpless arteriovenous extracorporeal removal of CO2 in a heart-beating donor awaiting organ harvest.

Serum procalcitonin concentration as a negative predictor of serious bacterial infection in acute sickle cell pain crisis

BACKGROUND

A pilot study was designed to determine if serum procalcitonin levels would assist in the diagnosis of severe bacterial infections in patients presenting to an emergency department (ED) with acute sickle cell pain crisis and evidence of acute inflammatory response.

MATERIAL/METHODS

Prospective single cohort study evaluating measured procalcitonin levels in patients with sickle cell pain crisis and evidence of acute inflammation. Acute inflammation was defined as fever (>38 degrees C) and/or elevation in the white blood cell count (>4000 above baseline) and tachycardia (heart rate >100). Procalcitonin was measured using a semi-quantitative monoclonal antibody test. Patients were followed clinically to determine if procalcitonin has predictive value in excluding severe bacterial infections.

RESULTS

Twenty four subjects were enrolled and completed the study. Sixteen had levels 0.5 ng/ml or less, two had levels 0.5 to 2 ng/ml, one had a level of 2 but less than 10 ng/ml, and four had levels 10 ng/ml or greater. All subjects with documented infections at presentation had procalcitonin levels > or =2.0 ng/ml. The sensitivity of the test in this study sample was 1, and the specificity was 0.95 (95% CI, 0.75-0.99).

CONCLUSIONS

A serum procalcitonin less than 2 ng/ml appears to have good negative predictive value in excluding serious bacterial infections in patients that present with acute sickle cell pain crisis and evidence of acute inflammatory response. Further study is needed to investigate if procalcitonin has positive predictive value in identifying patients with serious bacterial infections in this patient population.

Aerial contamination of fruit through wet deposition and particulate dry deposition

The current state of knowledge concerning the processes and pathways which lead to the contamination of fruit crops by non-gaseous airborne contaminants is reviewed. Given the wide range of fruit canopies which occur, it is necessary to look for generic factors which affect the contribution of each of these processes and pathways to distribution through the canopy, losses from the canopy back to the atmosphere, and the fate of particle-bound substances once attached to the canopy. This latter stage represents perhaps the greatest source of uncertainty in determining levels of contamination. For wet deposition, the controlling factors appear to be the ability of the canopy surface to store precipitated water, and the interaction of the contaminant species with the leaf cuticle, which appears to act as an ion exchange medium, selectively accumulating certain ionic species. Where possible, models and parameterisations are provided for these stages. A summary is given of current data requirements for those cases where this is not possible.

Quinolone antibiotics in the treatment of Salmonella infections

The 4-fluoroquinolones are a new class of antimicrobial agents that possess broad in vitro antibacterial activity, including efficacy against enteric pathogens such as Salmonella, Shigella, Campylobacter, Yersinia, and Vibrio species. These drugs are clinically effective against both drug-sensitive and multiresistant strains of Salmonella typhi and Salmonella paratyphi that cause enteric fever. In salmonella enterocolitis, the quinolones--unlike older antimicrobial agents that may have little impact on the duration of symptomatic illness and can in fact prolong fecal carriage of salmonellae--actually shorten the course of clinical disease and terminate excretion of these organisms in the stool. Similarly, for chronic carriers of both typhoidal and nontyphoidal Salmonella strains, the quinolones are effective in eradicating biliary and fecal reservoirs of infection. Immunosuppressed persons with salmonellosis, such as those with AIDS, may benefit from both short-term treatment and prolonged prophylaxis with a quinolone antibiotic. The optimal agent, dose, and duration of quinolone therapy for all salmonella syndromes remain to be determined by larger controlled trials.

Respiration and osmoregulation of the estuarine crab, Rhithropanopeus harrisii (Gould): effects of the herbicide, alachlor

1. The effects of a sudden decrease in salinity and exposure to sublethal concentrations of the herbicide, alachlor, on osmoregulation and respiration of the crab, Rithropanopeus harrisii, were studied. 2. Crabs were hyperosmotic regulators at salinities below 24 ppt and became hypoosmotic at higher salinities. Upon a salinity decrease from 20 to 1 ppt, crabs adjusted their haemolymph osmolality to a stable hyperosmotic level in 8 hr. Alachlor concentrations to 50 ppm did not affect this adjustment. 3. A salinity decrease from 10 to 0 ppt elevated VO2 and the critical oxygen tension. This response was unaffected by alachlor concentrations as high as 25 ppm.

The relationship between prior clerkship experience and student performance in medicine clerkships. Implications for grading

The purpose of this study was to examine the relationships between prior clerkship experience and student performance in a third-year medicine clerkship. Trend analysis was used to determine if there was a linear relationship between amount of prior clerkship experience and scores on the following performance measures: subjective preceptor ratings; locally developed examinations; and the National Board of Medical Examiners (NBME) Special Examination in Medicine. Results indicated a positive linear relationship between amount of prior experience and the NBME Special Examination in Medicine, but no trends were found for the other performance measures. The effect was found to be a short-term phenomenon, in that no sequencing effect was evident from 1 to 2 years later, as indicated by scores on the Medicine subtest of NBME II. Implications for grading are discussed.

The effectiveness of progressive relaxation in chronic hemodialysis patients

An experimental group of 38 patients on chronic hemodialysis were presented a 30-min, self-instructional, color videotape on progressive relaxation (PR) exercises; and a control group of 23 patients viewed a neutral videotape. Both groups were given the State-Trait Anxiety Inventory while on the dialysis machine, before and after the actual viewing. The experimental group significantly reduced its state anxiety level while the control group remained the same. Patients who reported higher levels of state anxiety and experienced tension more frequently tended to achieve the greater benefit from the program. It is postulated that PR can be a useful resource to overcome the sometimes severe anxiety related to the stresses of chronic hemodialysis.

Impact of a colposcopy satellite clinic

A community educational program and the introduction of a colposcope in Decatur, Alabama, led to a dramatic decrease in the relative percent of patients evaluated by conization after a positive Pap smear, and a corresponding increase in the relative percent of colposcopic evaluations. The percent of negative or dysplastic tissue diagnoses from conization was reduced from 78% before the colposcopy program to 61% after the program. It was estimated that the colposcopy program resulted in an 81% reduction in the number of conizations and that colposcopy used in lieu of conization resulted in a substantial reduction in both morbidity and cost.

The effects of commercial coaching or the NBME Part I Examination

A total of 55 second-year medical students from the University of Alabama in Birmingham utilized the services of a commercial test-coaching company to assist them in preparations for the June 1977, 1978, and 1979 National Board of Medical Examiners Part I examination. These students scored significantly higher on the examination than students with comparable basic science grade-point averages. Students were surveyed to determine the nature of the course and to identify the salient points which they believed contributed to higher Part I scores. The study raises questions concerning the impact of commercial coaching on the licensure process for both domestic students and students of foreign medical schools entering the U.S. medical profession.

Attitude change in a human sexuality course that de-emphasizes small group activities

The attitudes of second-year medical students were measured to determine if positive attitude changes could be obtained in a human sexuality course that de-emphasized small group activities. Students were given a semantic differential instrument and were asked to rate four concepts related to human sexuality: (a) my sexuality, (b) masturbation, (c) homosexuality, and (d) my role in understanding sexual problems. Significant changes in student attitudes were reported at the 0x05 level for the concept, my sexuality; at the 0x01 level for the concept, my role in understanding sexual problems; and at the 0x001 level for the concepts, homosexuality and masturbation. Females had more positive attitudes (P < 0x001), pre and post, towards homosexuality than did males. No significant differences were found between married and single students.