CARDIAC OUTPUT IN CRITICALLY ILL PATIENTS CAN BE ESTIMATED EASILY AND ACCURATELY USING THE MINUTE DISTANCE OBTAINED BY PULSED-WAVE DOPPLER

ABSTRACT

Background: Cardiac output (CO) assessment is essential for management of patients with circulatory failure. Among the different techniques used for their assessment, pulsed-wave Doppler cardiac output (PWD-CO) has proven to be an accurate and useful tool. Despite this, assessment of PWD-CO could have some technical difficulties, especially in the measurement of left ventricular outflow tract diameter (LVOTd). The use of a parameter such as minute distance (MD) which avoids LVOTd in the PWD-CO formula could be a simple and useful way to assess the CO in critically ill patients. Therefore, the aim of this study was to evaluate the correlation and agreement between PWD-CO and MD. Methods: A prospective and observational study was conducted over 2 years in a 30-bed intensive care unit (ICU). Adult patients who required CO monitoring were included. Clinical echocardiographic data were collected within the first 24 h and at least once more during the first week of ICU stay. PWD-CO was calculated using the average value of three LVOTd and left ventricular outflow tract velocity-time integral (LVOT-VTI) measurements, and heart rate. Minute distance was obtained from the product of LVOT-VTI × heart rate. Pulsed-wave Doppler cardiac output was correlated with MD using linear regression. Cardiac output was quantified from the MD using the equation defined by linear regression. Bland-Altman analysis was also used to evaluate the level of agreement between CO calculated from MD (MD-CO) and PWD-CO. The percentage error was calculated. Results: A total of 98 patients and 167 CO measurements were analyzed. Sixty-seven (68%) were male, the median age was 66 years (interquartile range [IQR], 53-75 years), and the median Acute Physiology and Chronic Health Evaluation II score was 22 (IQR, 16-26). The most common cause of admission was shock in 81 patients (82.7%). Sixty-nine patients (70.4%) were mechanically ventilated, and 68 (70%) required vasoactive drugs. The median CO was 5.5 L/min (IQR, 4.8-6.6 L/min), and the median MD was 1,850 cm/min (IQR, 1,520-2,160 cm/min). There was a significant correlation between PWD-CO and MD-CO in the general population ( R2 = 0.7; P < 0.05). This correlation improved when left ventricular ejection fraction (LVEF) was less than 60% ( R2 = 0.85, P < 0.05). Bland-Altman analysis showed good agreement between PWD-CO and MD-CO in the general population, the median bias was 0.02 L/min, the limits of agreement were -1.92 to +1.92 L/min. The agreement was better in patients with LVEF less than 60% with a median bias of 0.005 L/min and limits of agreement of -1.56 to 1.55 L/min. The percentage error was 17% in both cases. Conclusion: Measurement of MD in critically ill patients provides a simple and accurate estimate of CO, especially in patients with reduced or preserved LVEF. This would allow earlier cardiovascular assessment in patients with circulatory failure, which is of particular interest in difficult clinical or technical conditions.

[Use of isoflurane as treatment for super-refractory status epilepticus]

INTRODUCTION

Super-refractory status epilepticus (SRSE) is a neurological condition with an important morbidity and mortality rate, for which few therapeutic options are available. Inhalation sedation with isoflurane is currently a compassionate-use treatment in Spanish intensive care units. Little has been written about its usefulness in the treatment of refractory and super-refractory status epilepticus, but it appears to be a useful and safe therapeutic alternative for this condition.

CASE REPORTS

This article reviews three cases of SRSE treated with isoflurane. The capacity of isoflurane to control seizures was assessed by electroencephalographic monitoring. Other variables assessed were time to seizure control, survival, functional outcome and occurrence of complications secondary to isoflurane. In the three cases reviewed, isoflurane proved to be effective for seizure control in patients affected by SRSE. Seizure control was accomplished quickly and the minimum dose required to obtain a burst-suppression pattern was titrated easily and rapidly. Despite controlling epilepsy, high mortality was observed (66.66%). This is explained by both the mortality of SRSE and the underlying pathologies of the patients who died. The use of isoflurane did not give rise to any complications.

CONCLUSION

With the results obtained, it is feasible to think that the use of isoflurane is not related to lesions in the central nervous system reported in other articles, and this treatment can be considered effective and safe for the control of SRSE.

Impact of Aspergillus spp. isolation in the first 24 hours of admission in critically ill patients with severe influenza virus pneumonia

OBJECTIVE

To determine the incidence and impact of Aspergillus spp. isolation (AI) on ICU mortality in critically ill patients with severe influenza pneumonia during the first 24h of admission.

DESIGN

Secondary analysis of an observational and prospective cohort study.

SETTING

ICUs voluntary participating in the Spanish severe Influenza pneumonia registry, between June 2009 and June 2019.

PATIENTS

Consecutive patients admitted to the ICU with diagnosis of severe influenza pneumonia, confirmed by real-time polymerase chain reaction.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

Incidence of AI in respiratory samples. Demographic variables, comorbidities, need for mechanical ventilation and the presence of shock according at admission. Acute Physiology and Chronic Health Evaluation II (APACHE II) scale calculated on ICU admission.

RESULTS

3702 patients were analyzed in this study. AI incidence was 1.13% (n=42). Hematological malignancies (OR 4.39, 95% CI 1.92-10.04); HIV (OR 3.83, 95% CI 1.08-13.63), and other immunosuppression situations (OR 4.87, 95% CI 1.99-11.87) were factors independently associated with the presence of Aspergillus spp. The automatic CHAID decision tree showed that hematologic disease with an incidence of 3.3% was the most closely AI related variable. Hematological disease (OR 2.62 95% CI 1.95-3.51), immunosuppression (OR 2.05 95% CI 1.46-2.88) and AI (OR 3.24, 95% CI 1.60-6.53) were variables independently associated with ICU mortality.

CONCLUSIONS

Empirical antifungal treatment in our population may only be justified in immunocompromised patients. In moderate-high risk cases, active search for Aspergillus spp. should be implemented.

Descendants of primed Arabidopsis plants exhibit resistance to biotic stress

An attack of plants by pathogens or treatment with certain resistance-inducing compounds can lead to the establishment of a unique primed state of defense. Primed plants show enhanced defense reactions upon further challenge with biotic or abiotic stress. Here, we report that the primed state in Arabidopsis (Arabidopsis thaliana) is still functional in the next generation without additional treatment. We compared the reactions of Arabidopsis plants that had been either primed with β-amino-butyric acid (BABA) or with an avirulent isolate of the bacteria Pseudomonas syringae pv tomato (PstavrRpt2). The descendants of primed plants showed a faster and higher accumulation of transcripts of defense-related genes in the salicylic acid signaling pathway and enhanced disease resistance upon challenge inoculation with a virulent isolate of P. syringae. In addition, the progeny of primed plants was also more resistant against the oomycete pathogen Hyaloperonospora arabidopsidis. When transgenerationally primed plants were subjected to an additional priming treatment, their descendants displayed an even stronger primed phenotype, suggesting that plants can inherit a sensitization for the priming phenomenon. Interestingly, this primed to be primed phenotype was much reduced in the Arabidopsis β-amino-butyric acid priming mutant ibs1 (induced BABA sterility1). Our results demonstrate that the primed state of plants is transferred to their progeny and confers improved protection from pathogen attack as compared to the descendants of unprimed plants.

Descendants of primed Arabidopsis plants exhibit resistance to biotic stress

An attack of plants by pathogens or treatment with certain resistance-inducing compounds can lead to the establishment of a unique primed state of defense. Primed plants show enhanced defense reactions upon further challenge with biotic or abiotic stress. Here, we report that the primed state in Arabidopsis (Arabidopsis thaliana) is still functional in the next generation without additional treatment. We compared the reactions of Arabidopsis plants that had been either primed with β-amino-butyric acid (BABA) or with an avirulent isolate of the bacteria Pseudomonas syringae pv tomato (PstavrRpt2). The descendants of primed plants showed a faster and higher accumulation of transcripts of defense-related genes in the salicylic acid signaling pathway and enhanced disease resistance upon challenge inoculation with a virulent isolate of P. syringae. In addition, the progeny of primed plants was also more resistant against the oomycete pathogen Hyaloperonospora arabidopsidis. When transgenerationally primed plants were subjected to an additional priming treatment, their descendants displayed an even stronger primed phenotype, suggesting that plants can inherit a sensitization for the priming phenomenon. Interestingly, this primed to be primed phenotype was much reduced in the Arabidopsis β-amino-butyric acid priming mutant ibs1 (induced BABA sterility1). Our results demonstrate that the primed state of plants is transferred to their progeny and confers improved protection from pathogen attack as compared to the descendants of unprimed plants.

Descendants of primed Arabidopsis plants exhibit resistance to biotic stress

An attack of plants by pathogens or treatment with certain resistance-inducing compounds can lead to the establishment of a unique primed state of defense. Primed plants show enhanced defense reactions upon further challenge with biotic or abiotic stress. Here, we report that the primed state in Arabidopsis (Arabidopsis thaliana) is still functional in the next generation without additional treatment. We compared the reactions of Arabidopsis plants that had been either primed with β-amino-butyric acid (BABA) or with an avirulent isolate of the bacteria Pseudomonas syringae pv tomato (PstavrRpt2). The descendants of primed plants showed a faster and higher accumulation of transcripts of defense-related genes in the salicylic acid signaling pathway and enhanced disease resistance upon challenge inoculation with a virulent isolate of P. syringae. In addition, the progeny of primed plants was also more resistant against the oomycete pathogen Hyaloperonospora arabidopsidis. When transgenerationally primed plants were subjected to an additional priming treatment, their descendants displayed an even stronger primed phenotype, suggesting that plants can inherit a sensitization for the priming phenomenon. Interestingly, this primed to be primed phenotype was much reduced in the Arabidopsis β-amino-butyric acid priming mutant ibs1 (induced BABA sterility1). Our results demonstrate that the primed state of plants is transferred to their progeny and confers improved protection from pathogen attack as compared to the descendants of unprimed plants.

AtsPLA2-alpha nuclear relocalization by the Arabidopsis transcription factor AtMYB30 leads to repression of the plant defense response

The hypersensitive response (HR), characterized by a rapid and localized cell death at the inoculation site, is one of the most efficient resistance reactions to pathogen attack in plants. The transcription factor AtMYB30 was identified as a positive regulator of the HR and resistance responses during interactions between Arabidopsis and bacteria. Here, we show that AtMYB30 and the secreted phospholipase AtsPLA(2)-alpha physically interact in vivo, following the AtMYB30-mediated specific relocalization of AtsPLA(2)-alpha from cytoplasmic vesicles to the plant cell nucleus. This protein interaction leads to repression of AtMYB30 transcriptional activity and negative regulation of plant HR. Moreover, Atspla(2)-alpha mutant plants are more resistant to bacterial inoculation, whereas AtsPLA(2)-alpha overexpression leads to decreased resistance, confirming that AtsPLA(2)-alpha is a negative regulator of AtMYB30-mediated defense. These data underline the importance of cellular dynamics and, particularly, protein translocation to the nucleus, for defense-associated gene regulation in plants.

Biotransformation of the polycyclic musks HHCB and AHTN and metabolite formation by fungi occurring in freshwater environments

Micropollutants found in aquatic environments have increasingly raised concerns with respect to their uncertain environmental fate and potentially adverse effects on human health and the environment. The biodegradability of two major representatives of the polycyclic musk fragrances, Galaxolide (HHCB) and Tonalide (AHTN), and the formation of biotransformation metabolites, were investigated with Myrioconium sp. strain UHH 1-13-18-4 and Clavariopsis aquatica, two mitosporic fungi derived from freshwater environments. A particular focus was to assess the effects of extracellular oxidoreductases such as laccases, which are produced by the investigated fungi under certain conditions, on HHCB and AHTN. The fungi converted HHCB and AHTN into various products via initial hydroxylation at different carbon positions. Further metabolism resulted in the subsequent formation of diketone, peroxide, and O-methylated derivatives. Isolated laccases of the investigated fungi were able to oxidize HHCB and AHTN and catalyzed the formation of the metabolite HHCB-lactone from HHCB. At particular environmental situations also specified within the present study, biotransformations catalyzed by fungi occurring in freshwater environments may be considered when addressing the fate of polycyclic musks in freshwater systems and potential biological effects of their degradation metabolites.

CK2 phosphorylation of CCA1 is necessary for its circadian oscillator function in Arabidopsis

The circadian clock controls numerous physiological and molecular processes in organisms ranging from fungi to human. In plants, these processes include leaf movement, stomata opening, and expression of a large number of genes. At the core of the circadian clock, the central oscillator consists of a negative autoregulatory feedback loop that is coordinated with the daily environmental changes, and that generates the circadian rhythms of the overt processes. Phosphorylation of some of the central oscillator proteins is necessary for the generation of normal circadian rhythms of Drosophila, humans, and Neurospora, where CK1 and CK2 are emerging as the main protein kinases involved in the phosphorylation of PER and FRQ. We have previously shown that in Arabidopsis, the protein kinase CK2 can phosphorylate the clock-associated protein CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) in vitro. The overexpression of one of its regulatory subunits, CKB3, affects the regulation of circadian rhythms. Whether the effects of CK2 on the clock were due to its phosphorylation of a clock component had yet to be proven. By examining the effects of constitutively expressing a mutant form of the Arabidopsis clock protein CCA1 that cannot be phosphorylated by CK2, we demonstrate here that CCA1 phosphorylation by CK2 is important for the normal functioning of the central oscillator.

A R2R3-MYB gene, AtMYB30, acts as a positive regulator of the hypersensitive cell death program in plants in response to pathogen attack

Hypersensitive response (HR) is a programmed cell death that is commonly associated with disease resistance in plants. Among the different HR-related early induced genes, the AtMYB30 gene is specifically, rapidly, and transiently expressed during incompatible interactions between Arabidopsis and bacterial pathogens. Its expression was also shown to be deregulated in Arabidopsis mutants affected in the control of cell death initiation. Here, we demonstrate that overexpression in Arabidopsis and tobacco of AtMYB30 (i) accelerates and intensifies the appearance of the HR in response to different avirulent bacterial pathogens, (ii) causes HR-like responses to virulent strains, and (iii) increases resistance against different bacterial pathogens, and a virulent biotrophic fungal pathogen, Cercospora nicotianae. In antisense AtMYB30 Arabidopsis lines, HR cell death is strongly decreased or suppressed in response to avirulent bacterial strains, resistance against different bacterial pathogens decreased, and the expression of HR- and defense-related genes was altered. Taken together, these results strongly suggest that AtMYB30 is a positive regulator of hypersensitive cell death.

A novel myb oncogene homologue in Arabidopsis thaliana related to hypersensitive cell death

A novel myb oncogene homologue (AtMYB30) has been isolated by differential screening of a cDNA library prepared from Xanthomonas campestris pv. campestris (X. campestris)-inoculated Arabidopsis thaliana cells cultured in the presence of cycloheximide. AtMYB30 is a single-copy gene, and the encoded protein contains a MYB domain highly homologous to other plant and animal MYB proteins. Analyses of transcript levels in A. thaliana plants, or in cultured A. thaliana cells infected with either virulent or avirulent strains of the pathogens X. campestris and Pseudomonas syringae pv. tomato, showed that maximal levels of transcription of this gene occurred during the hypersensitive response. Furthermore, in A. thaliana mutants affected in the control of cell death initiation (lsd3, lsd4 and lsd5), constitutive expression or expression in lesion-positive plants was observed, while in suppressors of the mutations lsd5 and lsd4, AtMYB30 transcripts did not accumulate. However, AtMYB30 expression could not be detected in the lsd1 mutant, which was hyper-responsive to cell death initiators and unable to limit the extent of cell death, whatever the environmental conditions. The results presented here suggest a strong correlation between AtMYB30 and genetically controlled cell death, with a role in the initiation of cell death rather than in the limitation of its extent. Our results further indicate that the lsd mutants constitute an appropriate genetic model for studying the role of this gene in hypersensitive cell death, and their relation to different steps of the pathway(s) leading to cell death.