Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications

BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (VT) size was 500 ml, or 7 to 9 ml kg1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P < 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P < 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high VT and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome

Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications: LAS VEGAS - An observational study in 29 countries

BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (V T) size was 500 ml, or 7 to 9 ml kg−1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P ˂ 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P ˂ 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high V T and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome.</p

The ammonium fixation in great soil groups of Tokat region and some factors affecting the fixation - I. The affect of potassium on ammonium fixation

The objective of this study was to evaluate the fixation of ammonium in the soils of Tokat region to find out the important factors influencing them. For this purpose 12 representative soil samples were collected from different Great Soil Groups in the region. The amount of ammonium fixed naturally in the samples was found between 41.62-66.90 ppm ammonium (0.29-0.47 me NH4-N/100 g. soil). The amounts of ammonium fixed by the soils where increasing amounts of ammonium applied were found between 0.63-1.29%. There was a significant effect from application of potassium to the soils on the fixation of ammonium. Potassium applied before ammonium decreased the ammonium fixation in all soils, but when it was applied with ammonium it increased the ammonium fixation in other soils except in Ustifluvent 1-2. Ustorthent 2 and Haplustalf 1-2

Response of strawberry grown at high salinity and alkalinity to supplementary potassium

Strawberry (Fragaria x ananassa Duch) cv. "Oso Grande" was grown in sand culture out-of-doors to investigate the effectiveness of supplementary potassium (K) applied to the root zone at high (35 mM) NaCl and high pH (8.5). Treatments were (1) normal nutrient solution alone (C), (2) normal nutrient solution plus 35 mMNaCl (C + S), and (3) plants receiving normal nutrient solution and 35 mM NaCl plus 3 mM KSO supplemented in nutrient solution (C + S + K). Two pH levels (5.5 or 8.5) were combined with the above treatments (C, C + S, and C + S + K). The plants grown at high NaCl and pH produced less dry matter, fruit yield and chlorophyll than those in normal nutrient solution (C). Potassium supplemented into nutrient solution resulted in increases in dry matter, chlorophyll concentrations and fruit yield of strawberry. The deleterious effect of high salinity on plant growth was more striking than that of high pH (8.5). Membrane permeability increased with addition of 35 mM NaCl and increasing pH from 5.5 to 8.5. Supplementary K decreased membrane permeability. Sodium (Na) concentration in plant tissues increased in the elevated NaCl and pH treatments. Concentration of K was much lower in the plants grown at high NaCl and supplementary K application enhanced the K concentration within the plants. These findings suggest that supplementary K can improve plant growth and fruit yield and quality grown under saline conditions.Peer reviewe

Supplementary calcium enhances plant growth and fruit yield in strawberry cultivars grown at high (NaCL) salinity

Copyright 2008 Elsevier B.V., All rights reserved.Strawberry (Fragaria × ananassa Duch) cvs. 'Oso Grande' and 'Camarosa' were grown in sand culture out-of-doors to investigate the effectiveness of supplementary calcium (Ca) applied into nutrient solution on plants grown at high (35 mM) NaCl concentration. Treatments were: (1) nutrient solution alone (C); (2) nutrient solution plus 35 mM NaCl (C + S); (3) nutrient solution and 35 mM sodium chloride plus supplementary 5 mM Ca as CaCl supplied in nutrient solution (C + S + Ca). Dry matter, fruit yield and chlorophyll content of plants grown at high NaCl were less than those at normal nutrient solution. Supplementary Ca ameliorated the negative effects of salinity on plant growth and fruit yield. Water use by plants decreased with elevated NaCl and increased with supplementary Ca. Membrane permeability increased with high NaCl application and these increases in membrane permeability were decreased with supplementary Ca. Sodium (Na) concentration in plant tissues increased in both cultivars in the high NaCl level. Concentrations of Ca were at deficient ranges in the plants grown at high NaCl levels and these deficiencies were corrected by supplementary Ca.Peer reviewe

Modelling nitrogen uptake and potential nitrate leaching under different irrigation programs in nitrogen-fertilized tomato using the computer program NLEAP

PubMedID: 15736886Readily available nitrogen (N) sources such as ammonium nitrate with excessive irrigation present a potential hazard for the environment. The computer program Nitrate Leaching and Economic Analysis Package (NLEAP) is a mechanistic model developed for rapid site-specific estimates of nitrate-nitrogen (NO3-N) moving below the root zone in agricultural crops and potantial impacts of NO3-N leaching into groundwater. In this study, the value of NLEAP was tested to simulate N uptake by crops and NO3-N leaching parameters in large lysimeters under the tomato crop. Three seedlings of tomato variety of H-2274 (Lycopersicum esculentum L.) were transplanted into each lysimeter. N fertilizer at the rate of 140 kg N ha-1 was sidedressed in two split applications, the first half as ammonium sulphate and the second half as ammonium nitrate. The lysimeters were irrigated based on programs of C 0.75, 1.00, 1.25 and 1.50, C referring to class A-Pan evaporation coefficients. Parameters such as leaching index (LI), annual leaching risk potential (ALRP), N available for leaching (NAL), amount of NO3-N leached (NL) and amount of N taken up by the crops (NU) were estimated using the NLEAP computer model. To test the ability of model to simulate N uptake and NL, measured values were compared with simulated values. Significant correlations, R2 = 0.92 and P &lt; 0.03 for the first year and R2 = 0.86 and P &lt; 0.06 for the second year, were found between measured and simulated values for crop N consumption, indicating that the NLEAP model adequately described crop N uptake under the varied irrigation programs using an optimal N fertilization program for the experimental site. Significant correlations, R2 = 0.96 and P &lt; 0.01 for the first year and R2 = 0.97 and P &lt; 0.01 for the second year, were also found between measured and simulated values of NL, indicating that the NLEAP model also adequately predicted NL under the varied irrigation programs. Therefore, this computer model can be useful to estimate the NO3-N moving beyond the root zone under conditions in which the present experiment was carried out. Also, the NLEAP-estimated NAL values and other parameters can also be used to improve N management practices and N fertilizer recommendations that will help to decrease the adverse effect of N fertilizer on groundwater quality and farm profitability. © Springer Science + Business Media, Inc. 2005

Modeling nitrogen uptake and potential nitrate leaching under different irrigation programs in nitrogen-fertilized tomato using the computer program NLEAP

WOS: 000226975900016PubMed ID: 15736886Readily available nitrogen (N) sources such as ammonium nitrate with excessive irrigation present a potential hazard for the environment. The computer program Nitrate Leaching and Economic Analysis Package (NLEAP) is a mechanistic model developed for rapid site-specific estimates of nitrate-nitrogen (NO3-N) moving below the root zone in agricultural crops and potantial impacts of NO3-N leaching into groundwater. In this study, the value of NLEAP was tested to simulate N uptake by crops and NO3-N leaching parameters in large lysimeters under the tomato crop. Three seedlings of tomato variety of H-2274 (Lycopersicinn esculentum L.) were transplanted into each lysimeter. N fertilizer at the rate of 140 kg N hat was sidedressed in two split applications, the first half as ammonium sulphate and the second half as ammonium nitrate. The lysimeters were irrigated based on programs of C 0.75,1.00,1.25 and 1.50, C referring to class A-Pan evaporation coefficients. Parameters such as leaching index (LI), annual leaching risk potential (ALRP), N available for leaching (NAL), amount of NO3-N leached (NL) and amount of N taken up by the crops (NU) were estimated using the NLEAP computer model. To test the ability of model to simulate N uptake and NL, measured values were compared with simulated values. Significant correlations, R-2 = 0.92 and P < 0.03 for the first year and R-2 = 0.86 and P < 0.06 for the second year, were found between measured and simulated values for crop N consumption, indicating that the NLEAP model adequately described crop N uptake under the varied irrigation programs using an optimal N fertilization program for the experimental site. Significant correlations, R-2 = 0.96 and P < 0.01 for the first year and R-2 = 0.97 and P < 0.01 for the second year, were also found between measured and simulated values of NL, indicating that the NLEAP model also adequately predicted NL under the varied irrigation programs. Therefore, this computer model can be useful to estimate the NO3-N moving beyond the root zone under conditions in which the present experiment was carried out. Also, the NLEAP-estimated NAL values and other parameters can also be used to improve N management practices and N fertilizer recommendations that will help to decrease the adverse effect of N fertilizer on groundwater quality and farm profitability