PubMed Health⌕ Search

Biomedical subjects

M Planas

Publications and source records attributed to M Planas.

At least 37 records · Page 2Linked to original sources
PubMed1998

Gas exchange and pulmonary haemodynamic responses to fat emulsions in acute respiratory distress syndrome.

OBJECTIVE: To investigate the gas exchange and pulmonary haemodynamic responses to two different intravenous fat emulsions in patients with acute respiratory distress syndrome (ARDS). DESIGN: Prospective, randomized, double-blind, placebo-controlled study. SETTING: Intensive care unit in a university-affiliated hospital. PATIENTS: 21 patients with ARDS [mean age, 57 +/- 3 (SEM) years; Acute Physiology and Chronic Health Evaluation II, 20 +/- 3; Murray's score, 2.85 +/- 0.12] consecutively admitted. INTERVENTIONS: Patients were assigned to three groups (n = 7 each): group A (LCT) received long-chain triglycerides (20% LCT), group B (MCT/LCT), medium-chain triglycerides/long-chain triglycerides (20% MCT/LCT: 50/50) and group C placebo (0.9% sodium chloride, NaCl). The infusion was always given at the rate of 2 mg/kg min over a total period of 12 h, with a volume infusion of 500 ml in each group. MEASUREMENTS: Data were collected before, immediately after and 12 h after infusion ceased. Pulmonary and systemic haemodynamic and gas exchange variables were measured at each time point. Serum triglyceride cholesterol, and non-esterified fatty acids levels were measured. RESULTS: During LCT infusion, cardiac output, oxygen consumption and oxygen delivery increased (all p < 0.05), whereas pulmonary haemodynamics, arterial oxygen tension, mixed venous partial pressure of oxygen and venous admixture ratio remained essentially unaltered. No changes were observed following MCT/LCT infusion. CONCLUSIONS: The administration of LCT emulsion given at a slow rate did not alter arterial oxygenation because of the beneficial effect of a high cardiac output, hence offsetting the detrimental effect of increased O2 consumption.

Adult↗
PubMed1998

Effect of inverse I:E ratio ventilation on pulmonary gas exchange in acute respiratory distress syndrome.

BACKGROUND: It is not known whether inverse I:E ratio ventilation (IRV) offers any real benefit over conventional mechanical ventilation with positive end-expiratory pressure (CMV-PEEP) at similar levels of end-expiratory pressure. METHODS: The effects of volume-controlled and pressure-controlled IRV (VC-IRV and PC-IRV, respectively) on VA/Q inequality were compared with those of CMV-PEEP at a similar level of end-expiratory pressure and with CMV without PEEP (CMV) in eight patients in the early stages of acute respiratory distress syndrome (ARDS). Respiratory blood gases, inert gases, lung mechanics, and hemodynamics were measured 30 min after the onset of each ventilatory mode. RESULTS: Recruitment of nonventilated, poorly ventilated (or both) but well-perfused alveoli increased the partial pressure of oxygen (PaO2) during CMV-PEEP (+13 mmHg) and IRV-VC (+10 mmHg; P < 0.05) compared with CMV. In contrast, PC-IRV did not affect PaO2 but caused a decrease in PaCO2 (-7 mmHg; P < 0.05). The latter was due to a concomitant decrease in dead space (P < 0.01) and shift to the right of VA/Q distributions. During PC-IRV, the increase in the mean of blood flow distribution (mean Q; P < 0.01) without a change in the dispersion (log SD Q) did not result in an increase in PaO2, probably because it reflected redistribution of blood flow within well-ventilated areas. CONCLUSIONS: Short-term PC-IRV improved carbon dioxide clearance, but the lung became less efficient as an oxygen exchanger. Furthermore, based on mean airway and plateau pressures, the risk of barotrauma was not reduced with this type of ventilation.

Adult↗
PubMed1997

Neurological disturbances and hyperdynamic shock in a patient with esophagocoloplasty.

A 39-year-old man, with no history of alcohol intake, who had had an esophago-ileo-colo-gastroplasty with ileotransversostomy, developed diplopia, seizures, metabolic acidosis, and cardiac failure and finally refractory hyperdynamic shock. He died 20 h after admission to our intensive care unit from cardiocirculatory collapse. Postmortem results revealed low erythrocyte transketolase activity, which was increased by 22% by in vitro addition of thiamine diphosphate (TDP effect). Cerebral pathology showed the alterations of Wernicke's encephalopathy. We discuss the possible mechanisms of fatal cardiovascular collapse and the unusual presentation of a case without a history of alcoholic intake or clinical malnutrition.

Acidosis↗
PubMed1997

Eicosanoids and fat emulsions in acute respiratory distress syndrome patients.

Lipid emulsions have been associated with changes in pulmonary function. Although these changes were related to the physical effects of the infusion-induced lipemia on gas exchange, several animal and human studies suggest that the impairment in pulmonary function observed with lipid infusions was mediated by prostaglandins. Prostaglandins are synthesized enzymatically from essential fatty acids. We studied the effects of two lipid emulsions, with different amounts of essential fatty acids (20% long-chain triacylglycerols [LCT] with 55% of linoleic acid and 7% of alpha linolenic acid in 100 g of emulsion, and a physical mixture of 20% medium-chain triacyglycerols [MCT] and LCT with 26% of linoleic acid and 4% of alpha linolenic acid in 100 g of emulsion), on plasma levels of eicosanoids in patients with acute respiratory distress syndrome (ARDS). Although in patients with ARDS, plasma levels of prostanoids were higher than the reference values, neither lipid emulsion, administered at the rate of 2 mg.kg-1.min-1 induced significant changes in the eicosanoids except for a decrease in systemic-pulmonary arterial 6-keto prostaglandin F1 alpha difference.

6-Ketoprostaglandin F1 alpha↗
PubMed1997

Parenteral administration of different amounts of branch-chain amino acids in septic patients: clinical and metabolic aspects.

OBJECTIVE: To study the effects of a total parenteral nutrition solution changing branch-chain amino acid concentrations and/or nitrogen supply on protein metabolism, length of stay, and mortality rate; and to evaluate the unique metabolic status of sepsis that leads to a search for specific total parenteral nutrition formulas. DESIGN: Prospective, randomized, and multicenter study. SETTING: Intensive care units (ICUs) in seven university hospitals. PATIENTS: Sixty-nine septic patients. MEASUREMENTS AND MAIN RESULTS: The patients were randomized into three groups according to the total parenteral nutrition administered. Group A (n = 22) and B (n = 25) patients received 1.5 g of amino acids/kg/day with a nonprotein ratio of 100:1 calories/g of nitrogen, and a varying branch-chain amino acids percentage (group A [23%); group B [45%]). Group C patients were treated with 1.1 g/kg/day of amino acids with a nonprotein ratio of 140:1 calories/g of nitrogen and 45% branch-chain amino acids. All diets were isocaloric. Prealbumin, retinol-binding protein, nitrogen balance, and plasma amino acid profiles (24 amino acids) were determined at baseline and after 3, 7, and 11 days of total parenteral nutrition. The length of stay and the mortality rate in the ICU were recorded. At baseline (preparenteral nutrition), no differences in age, gender, severity of the condition, or clinical chemistry were found between the groups. Prealbumin and retinol-binding protein increased in groups B (p < .004, p < .002, respectively) and C (p < .001, p < .002, respectively). Plasma arginine increased significantly in group C (p < .05), and plasma valine (p < .0001, p < .04, respectively), leucine (p < .005, p < .03, respectively), and isoleucine (p < .001, p < .0001, respectively) increased significantly in groups B and C. The length of stay in the ICU did not change between the groups. The mortality rate in groups B and C was less than in group A (p < .03). CONCLUSIONS: Our results suggest that the branch-chain amino acids-rich formulas (45%) show a beneficial effect in septic patients.

Amino Acids↗
PubMed1995

Artificial nutrition support in intensive care units in Spain. Nutritional and Metabolic Working Group of the Spanish Society of Intensive Care Medicine and Coronary Units (SEMIUC).

OBJECTIVE: A multicenter survey to study the use of nutritional support in patients admitted to the ICU in Spain. DESIGN: The survey was announced during the annual Spanish Society of Intensive Care Medicine and Coronary Units (SEMIUC) congress meeting. SETTING: Questionnaires designed to determine current clinical practice concerning artificial nutrition were sent to the 27 ICU who accepted to participate. PATIENTS AND PARTICIPANTS: In each center the 235-question form was filled out individually for each patient admitted to the ICU during the month of March, 1992. INTERVENTIONS: To validate the study a preliminary pilot surveys were conducted to ensure that there was a correct interpretation of the questions. The replies were entered into a database for analysis. RESULTS: A total of 1261 patients were studied; 33.9% received artificial nutrition (AN). The administration of AN was significantly higher in the medical group (44%), than in the surgical (37%) and the trauma group (19%). AN was significantly lower in patients admitted to private clinic than public institutions (26.7% versus 34.7%). Among the patients who received AN, enteral nutrition (EN) was administered to 59.7% of the patients, total parenteral nutrition (TPN) to 38.5%, and peripheral parenteral nutrition (PPN) to 18.2%. Medical patients received significantly more EN than surgical and trauma patients. Surgical patients received more PN than medical and trauma groups. CONCLUSIONS: Nutritional support is a common practice in the treatment of ICU patients in our country. All information concerning its use is necessary to optimize it.

Humans↗
PubMed1995

Protein synthesis in specific tissues during sepsis.

BACKGROUND: The hypothesis that fractional protein synthesis rates (Ks) are tissue-specific and bidirectional during sepsis was tested in an animal model. MATERIAL AND METHODS: Ks in liver, triceps muscle, and diaphragm were measured in septic (n = 27) and control rats (n = 26). Sepsis was induced by a reproducible model established in our laboratory (intraperitoneal injection of sterile NaOH 0.75 N at 0.075 ml/100 g of body weight). Ks were measured using the flooding-dose method in tissue obtained from the diaphragm, liver, and from the triceps muscle. RESULTS: In hepatic and diaphragmatic tissue, Ks were significantly higher in the septic animals (Ks: 112.2 +/- 8 and 5.4 +/- 1.9, respectively) than in control animals (Ks: 78.5 +/- 13 and 2.9 +/- 1.7, respectively). In the triceps, Ks were significantly lower in septic animals (Ks: 2.9 +/- 1.4) than in control animals (Ks: 5 +/- 1.8). CONCLUSION: The results suggest that in septic animals the rate of protein synthesis is enhanced in tissues of priority, such as the liver, and varies in response to differences in muscle activity.

Animals↗
PubMed1995

Pattern of tracheal colonization during mechanical ventilation.

The relationship between gastric (GC) and tracheal (TC) colonization and the development of ventilator-associated pneumonia (VAP) remains controversial. TC, GC, and pharyngeal (PC) colonization were studied serially in 80 patients with mechanical ventilation (MV) to ascertain the routes and onset of TC. Simultaneous sample from pharynx, stomach, and trachea were obtained throughout the MV period. Quantitative cultures were performed. Seventy-two patients (90%) had TC at some time during MV. Only 19 patients presented TC after PC or GC by the same microorganisms. Indigenous gram-negative and gram-positive microorganisms colonized mainly the trachea from the start of or during MV without previous PC or GC (p < 0.05). Pseudomonas were the microorganisms causing TC principally during MV without previous PC or GC (p < 0.005). Enterobacteria produced TC without a preferential route. Of the 12 patients who developed VAP, the microorganisms responsible had already colonized the trachea in 10 patients. Only 10 of the 21 microorganisms isolated in VAP had previously colonized the pharynx or stomach. In summary, although some microorganisms have preferential routes for producing TC, the microorganisms isolated frequently change during MV. TC precedes VAP in most patients, but only a minority develop a VAP; therefore, together with TC other factors must be involved in VAP development.

Adult↗
PubMed1994

Effect of two lipid emulsions on platelet function.

OBJECTIVE: To examine the effect of two lipid emulsions administered with total parenteral nutrition (TPN) on platelet aggregation and activation and the production of eicosanoids in nonseptic critically ill patients. DESIGN: Prospective, randomized, unblinded, non-crossover study. SETTING: ICU of a general teaching hospital. PATIENTS: 23 adult, critically ill, nonseptic patients, who were in need of TPN for at least 7 days. INTERVENTIONS: The patients were randomly distributed into 2 groups each of which received TPN with a different essential fatty acid content. The 2 lipid emulsions, Intralipid 20% (long-chain triglycerides) and Lipofundin MCT/LCT 20% (10% each of long- and medium-chain triglycerides) provided 43% of the nonprotein caloric requirements calculated for each patient. Parameters demonstrating platelet function (plasma beta-thromboglobulin, platelet factor 4, platelet aggregation, 6-keto-PGF1 alpha) were assessed before starting TPN and after 4 and 7 days of initiation. RESULTS: Before beginning lipid perfusion, platelet activation evaluated by beta TG and PF4 levels was notable, 6-keto-PGF1 alpha production was elevated and no hyperaggregation of platelets was observed in patients. The studies of platelet function at 4 and 7 days of TPN did not show significant changes with respect to the basal data or between the 2 groups. CONCLUSIONS: Our results indicate that platelet function was not affected by either of the 2 lipid emulsions administered to patients during the study period.

Adult↗
PubMed1993

[The effect of sepsis on liver protein synthesis].

A study was made of the possible influence of sepsis on liver protein synthesis in septic and control rats, fed either parenterally (TPN) or with water and feed available "ad libitum". Liver protein synthesis was determined using the single massive dose method. In experiment I, the septic and control animals received TPN for twenty-four hours: in experiment II water and food was available to them "ad libitum". Twenty-four hours after the sepsis occurred, the animals were injected with a massive dose of 14C-labelled leucine, and slaughtered by decapitation. The septic animals with water and feed available "ad libitum" were fasted voluntarily without any intake. This group of fasted septic animals was the only one which lost weight. Liver protein synthesis increased in septic animals in comparison with the control animals, whether receiving TPN (112.2 +/- 8/78.5 +/- 13) or with "ad libitum" nutrition (97.2 +/- 15/60.8 +/- 8). The increased liver protein synthesis in the septic animals was modified (although with reduced significance) by parenteral nutrition (112.2 +/- 8/97.2 +/- 15). Our results suggest that sepsis increases liver protein synthesis, and that this protein synthesis may be enhanced by parenteral nutrition.

Animals↗
PubMed1990

[Somatostatin and/or total parenteral nutrition for the treatment of intestinal fistulas].

61 patients with postoperative enterocutaneous fistulas of the small intestine, were admitted to the Intensive Care Unit from 1983 to 1989 and divided in two groups. Group A (n = 46) was treated with Total Parenteral Nutrition (TPN), while B (n = 15) received a combination of TPN and Somatostatin. The reduction of fistula output was significantly greater in group B. Spontaneous closure was observed in 30.4% of the cases in group A and in 53.3% in group B. A significant difference in the time taken to close the fistula between group A and B (29.7 +/- 18 versus 11.1 +/- 1.6 days) was observed.

Adult↗
PubMed1982

Characterization of acute renal failure in the burned patient.

In a retrospective review of 35 patients seen over a two-year period with second- and third-degree burns of 30% or more of their body surface area, six died within 48 hours. Of the remaining 29 patients, polyuric renal failure developed in ten. The functional pattern of this polyuric renal failure appears to be different from other forms of polyuric acute renal failure in that fractional excretion of urinary sodium remains low and the urine to plasma osmolality ratio is commonly above unity. This functional pattern is consistent with a reduction in glomerular filtration rate with a proximal tubular defect such that a "downstream" osmotic diuresis occurs. The distal nephron appears to be intact and functioning.

Acute Kidney Injury↗