Post-drought conditions and hydraulic dysfunction determine tree resilience and mortality across Mediterranean Aleppo pine (Pinus halepensis) populations after an extreme drought event.

Drought-related tree mortality is a global phenomenon that currently affects a wide range of forests. Key functional variables on plant hydraulics, carbon economy, growth and allocation have been identified and play a role in tree drought responses. However, tree mortality thresholds based on such variables are difficult to identify, especially under field conditions. We studied several Aleppo pine populations differently affected by an extreme drought event in 2014, with mortality rates ranging from no mortality to 90% in the most severely affected population. We hypothesized that mortality is linked with high levels of xylem embolism, i.e., hydraulic dysfunction, which would also lead to lower tree resistance to drought in subsequent years. Despite not finding any differences among populations in the vulnerability curves to xylem embolism, there were large differences in the hydraulic safety margin (HSM) and the hydraulic dysfunction level. High mortality rates were associated with a negative HSM when xylem embolism reached values over 60%. We also found forest weakening and post-drought mortality related to a low hydraulic water transport capacity, reduced plant growth, low carbohydrate contents and high pest infestation rates. Our results highlight the importance of drought severity and the hydraulic dysfunction level on pine mortality, as well as post-drought conditions during recovery processes.

Quantifying in situ phenotypic variability in the hydraulic properties of four tree species across their distribution range in Europe.

Many studies have reported that hydraulic properties vary considerably between tree species, but little is known about their intraspecific variation and, therefore, their capacity to adapt to a warmer and drier climate. Here, we quantify phenotypic divergence and clinal variation for embolism resistance, hydraulic conductivity and branch growth, in four tree species, two angiosperms (Betula pendula, Populus tremula) and two conifers (Picea abies, Pinus sylvestris), across their latitudinal distribution in Europe. Growth and hydraulic efficiency varied widely within species and between populations. The variability of embolism resistance was in general weaker than that of growth and hydraulic efficiency, and very low for all species but Populus tremula. In addition, no and weak support for a safety vs. efficiency trade-off was observed for the angiosperm and conifer species, respectively. The limited variability of embolism resistance observed here for all species except Populus tremula, suggests that forest populations will unlikely be able to adapt hydraulically to drier conditions through the evolution of embolism resistance.

Variation in xylem vulnerability to embolism in European beech from geographically marginal populations.

Climate change is expected to increase the frequency and intensity of droughts and heatwaves in Europe, leading to effects on forest growth and major forest dieback events due to hydraulic failure caused by xylem embolism. Inter-specific variability in embolism resistance has been studied in detail, but little is known about intra-specific variability, particularly in marginal populations. We evaluated 15 European beech populations, mostly from geographically marginal sites of the species distribution range, focusing particularly on populations from the dry southern margin. We found small, but significant differences in resistance to embolism between populations, with xylem pressures causing 50% loss of hydraulic conductivity ranging from -2.84 to -3.55 MPa. Significant phenotypic clines of increasing embolism resistance with increasing temperature and aridity were observed: the southernmost beech populations growing in a warmer drier climate and with lower habitat suitability have higher resistance to embolism than those from Northern Europe growing more favourable conditions. Previous studies have shown that there is little or no difference in embolism resistance between core populations, but our findings show that marginal populations have developed ways of protecting their xylem based on either evolution or plasticity.

Actuación de los pacientes ante un síndrome coronario agudo: diferencias desde una perspectiva de género / Patient responses to symptoms of acute coronary syndrome: a gender-perspective study

Objetivos: Conocer las características del entorno, pensamientos, actuaciones y tipo de transporte utilizado en hombres y mujeres con síndrome coronario agudo –SCA– (infarto agudo de miocardio y angina inestable) al inicio de los síntomas. Método: Estudio observacional descriptivo de una muestra representativa de pacientes ingresados en las unidades de cuidados intensivos de 33 hospitales públicos de las 8provincias andaluzas, entre 2007 y 2010, con diagnóstico al alta de SCA. Resultados: Se obtuvieron 1.416 encuestas: 948 hombres y 468 mujeres, con una edad media de 63,0 años y 70,5, respectivamente. Los síntomas se inician mayormente en la vivienda habitual y por la mañana. Menos de una tercera parte de las personas encuestadas supo desde el principio que se trataba de un infarto (hombres 29,9%, mujeres 24,2% p < 0,001). El 26,0% lo primero que hace es telefonear o desplazarse en busca de familiares, amistades o gente vecina, además las personas realizan más de (..) (AU)

Objective: To determine the environmental characteristics and the opinions, behaviors, and types of transfer to hospital of men and women who experience symptoms of acute coronary syndrome (acute myocardial infarct and unstable angina).Methods: Descriptive observational study of a representative sample of patients with a diagnosis of acute coronary syndrome who were admitted to the intensive care units of 33 public health service hospitals in 8 provinces in Andalusia, Spain, between 2007 and 2010.Results: A total of 1416 surveys were completed; 948 were for men and 468 were for women (mean [SD] ages, 63.0and 70.5 years, respectively). Symptoms usually began in the patient’s home. Fewer than a third of the patients surveyed knew they were experiencing a coronary event from the beginning of symptoms (29.9% of men and 24.2% of women;P<.001). The first reaction of 26.0% was to call or try to find a family member, friend, or neighbor. Many (..) (AU)

Thrombolysis with recombinant tissue plasminogen activator during cardiopulmonary resuscitation in fulminant pulmonary embolism. A case series.

OBJECTIVE: To describe our outcomes using thrombolysis during the cardiopulmonary resuscitation (CPR) of patients in cardiorespiratory arrest (CA) caused by fulminant pulmonary embolism (FPE). DESIGN: A case series. SETTING: Intensive care units of a district hospital and a referral centre. PATIENTS: Six patients that suffered CA secondary to an FPE. INTERVENTIONS: Administration of recombinant tissue plasminogen activator during usual CPR manoeuvres when there was a strong suspicion of FPE. Permission for the thrombolytic therapy was sought from family members in all cases. RESULTS: Four out of the six patients survived and remain symptom-free. The thrombolysis was not associated with any fatal complications. CONCLUSIONS: Early thrombolysis during CPR manoeuvres for CA apparently caused by an FPE may reduce the mortality rate among these patients.

Factors related to quality of life 12 months after discharge from an intensive care unit.

OBJECTIVE: To perform an analysis of the quality of life of survivors after ICU discharge. DESIGN: Prospective study. SETTING: Medical-surgical ICU of a Spanish reference hospital. PATIENTS: Patients (n = 606) admitted in a 6-month period. METHOD: A questionnaire regarding quality of life issues was completed at the time of admission by patients or surrogates (n = 606). The questionnaire was given again 12 months after ICU discharge to 444 surviving patients. Both questionnaires evaluated the patient's ability to function and communicate for the previous 3 months. A Quality of Life score of 0 corresponded to no limitations. An increasing score indicated a reduction in function. A score of greater than 10 points implied a severe physical handicap. Information was also collected on the severity of illness and the diagnosis that prompted ICU admission. RESULTS: The mean Quality of Life score of all survivors worsened from a mean of 4.62 at the time of ICU admission to a mean of 6.11 at 12 months after ICU discharge (p less than .01) and was most evident for patients greater than 75 yrs of age (from a mean of 6.33 to a mean of 9.54). However, patients with the highest initial Quality of Life scores had a significant improvement at 12 months (14.61 +/- 0.50 to 12.48 +/- 0.78 points [p less than .05]). A higher severity of illness score corresponded to a higher Quality of Life score, but a multivariate analysis indicated that the factors with the greatest influence on the post-discharge Quality of Life score were the initial Quality of Life score and age. CONCLUSIONS: Twelve months after discharge from the ICU, a patient's functional status, as measured by the Quality of Life score, is influenced most by age and their Quality of Life score at the time of ICU admission. While there is an overall decrease in the Quality of Life score for survivors, admission and treatment in an ICU do not always result in deterioration of the Quality of Life score. This study indicates that Quality of Life scores could become a routine part of patient evaluation.

Increase in lung volume originated by extrinsic PEEP in patients with auto-PEEP. The role of static lung compliance.

The use of extrinsic positive end expiratory pressure (PEEPe) in patients with auto-PEEP (AP) can reduce the respiratory work during weaning from mechanical ventilation. However, the application of PEEPe can produce a certain level of hyperinflation, an undesirable effect which can limit the efficacy of the reduction of respiratory work. The objective of the present study has been to determine if the increase in end expiratory lung volume (EELV) originated by the PEEPe is related to static lung compliance (SLC). We have studied 14 patients on mechanical ventilation in whom an AP of between 4 and 12 cmH2O was detected. On applying PEEPe equal to half the AP, the EELV increased slightly (77 +/- 64 ml) and was not related to pulmonary compliance. When PEEPe equal to the AP was applied, the EELV increased by 178 +/- 110 ml (range 45-375 ml, p less than 0.05), and there was a significant correlation with SLC (r = 0.659, p less than 0.05). In conclusion, the application of PEEPe equal to the AP causes a moderate increase in EELV. However, in patients with high pulmonary compliance this increase can be more important and must be taken into account when considering the use of PEEPe during weaning.

Variations in oxygen consumption and carbon dioxide production during parenteral nutrition.

To verify that variations caused by total parenteral nutrition (TPN) in O2 intake (VO2) and CO2 output (VCO2) can affect respiratory function of non-hypercatabolic patients, we studied 18 patients in two groups; group I (control): eight patients receiving 75-100 g glucose/24 h, and group II: ten patients fed intravenously on 13.6 g N2 and approximately 2,800 kcal/24 h given as a) 62% glucose + 38% fats (TPN-G + F) and b) 100% glucose (TPN-G). VO2, VCO2, respiratory quotient (RQ) and minute ventilation (VE) were measured in all patients. We found that VCO2 was 27% higher in intravenously fed patients (p less than 0.01 and p less than 0.02). Similarly, VE was 26% higher in intravenously fed patients (p less than 0.001 and p less than 0.02). Comparison of TPN-G + F and TPN-G results showed no differences in VCO2; by contrast, VO2 was 21% less during TPN-G (p less than 0.01).