Cardiac arrhythmias during central venous catheter procedures in acute renal failure: a prospective study.

To define the frequency and risk factors of cardiac arrhythmias during central venous catheter procedures in acute renal failure, continuous electrocardiographic monitoring with permanent recording was performed before and during 201 guidewire insertions in 171 patients requiring a central venous catheter for parenteral nutrition and/or dialysis access (121 procedures in 107 patients with acute renal failure; 39 procedures in 31 patients with normal renal function; 41 procedures in 33 patients with ESRD on chronic hemodialysis). No differences in cardiac arrhythmia frequencies were found during baseline recording. New arrhythmias were documented in 85 cases (85/201; 42%) during the catheter procedure.

[Physiopathology of respiratory muscles in malnutrition].

Objectives: a) To present the pathophysiological concepts behind undernutrition-related effects on respiratory muscle composition and function; b) to review the existing literature on the possible role of undernutrition-related effects on respiratory muscles as pathogenetic factors of ventilatory failure.

Data Sources: Selected recent references and pertinent literature in the english language dealing with the effects of undernutrition on respiratory muscle composition and function in the experimental and clinical settings.

Data Extraction: Peer-reviewed clinical or basic research journals.

Hemodynamic, respiratory, and metabolic effects of medium-chain triglyceride-enriched lipid emulsions following valvular heart surgery.

Study: A lipid emulsion containing 10 percent medium-chain triglycerides (MCT) and 10 percent long-chain triglycerides (LCT) was infused at a rate of 1 ml/kg/h (3.3 mg/kg/min) for 2 h, in 12 patients (2 males, 10 females; mean age, 54 +/- 3 (SEM) years; range, 34 to 67 years) 24 h after open-heart surgery (mitral valve replacement).

Methods: Hemodynamic factors (pulmonary and radial artery indwelling catheters), oxygen and carbon dioxide partial pressures, oxygen saturation, oxygen delivery and consumption, and intrapulmonary shunt fraction were obtained before, during, and after lipid infusion (for 2 h), at 30-s intervals, along with some metabolic indexes (triglycerides, free fatty acids, glucose, insulin, lactate, acetoacetate).

Hypophosphatemia and phosphorus depletion in respiratory and peripheral muscles of patients with respiratory failure due to COPD.

In 22 patients (19 men, 3 women; mean [+/- SD] age, 63 +/- 6 years) with chronic obstructive pulmonary disease (COPD), phosphorus content was measured by spectrophotometric methods on muscle fragments of both peripheral (quadriceps femoris needle biopsy in 22 patients) and respiratory muscles (external intercostal muscle surgical biopsy in 14 patients). Thirty age- and sex-matched subjects were used as controls (19 for quadriceps femoris muscle biopsy and 11 for intercostal muscle biopsy). Serum phosphorus levels, as well as the main determinants of overall phosphorus metabolism (dietary intake of phosphorus and renal phosphate handling), were also obtained in all patients and control subjects.

[Adherence to dietetic treatment, the nutritional metabolic status and the progression of chronic kidney failure].

Effects of two protein restricted diets on dietary compliance, nutritional and metabolic state, and progression of chronic renal failure (CRF) were investigated. Twenty-one patients with CRF were randomly assigned to either a conventional low protein diet (0.6 g of protein/kg b.

Pathophysiology of respiratory muscles in course of undernutrition.

Derangements of respiratory muscle function play a key role in the pathogenesis of respiratory failure, as they are able to determine respiratory pump failure and ventilatory insufficiency. Undernutrition negatively influences respiratory muscle function both directly through loss of contractile elements, and indirectly, through worsening or induction of muscle composition derangements. The present review focuses on the importance of undernutrition as a pathogenetic factor of altered respiratory muscle function: respiratory muscle structure and function derangements in both animal models of undernutrition and in undernourished subjects without lung disease are described.

Hypophosphatemia in course of chronic obstructive pulmonary disease. Prevalence, mechanisms, and relationships with skeletal muscle phosphorus content.

Serum phosphorus levels (Ps), dietary intake of phosphorus, and renal phosphate handling indexes were evaluated in 158 patients with chronic obstructive pulmonary disease (COPD) of varying degrees of severity; moreover, skeletal muscle phosphorus content (Pm) was measured in muscle samples obtained by quadriceps femoris needle biopsy in 14 of the same patients. Hypophosphatemia (Ps less than or equal to 2.5 mg/dl) was found in 34 (21.

Cell metabolism in patients undergoing major valvular heart surgery: relationship with intra and postoperative hemodynamics, oxygen transport, and oxygen utilization patterns.

The relationships between cell metabolism and both hemodynamics and oxygen transport/utilization (VO2/DO2) pattern were evaluated intra and postoperatively in eight patients undergoing major valvular heart surgery with the aid of moderately hypothermic cardiopulmonary bypass (CPB). Quadriceps femoris specimens were obtained by the needle biopsy technique for muscle ATP, ADP, AMP, phosphocreatine (PCr), creatine and lactate determination at anesthesia induction, after CPB, as well as in the ICU 18 h after surgery. Moreover, hemodynamic variables, oxygen transport and utilization indices, and plasma lactate were measured at the same intervals and throughout the CPB period.

Hypercapnic-hypoxemic chronic obstructive pulmonary disease (COPD): influence of severity of COPD on nutritional status.

In 90 patients with hypercapnic-hypoxemic chronic obstructive pulmonary disease (COPD), noninvasive anthropometric and biochemical nutritional indices were measured to assess the prevalence and features of malnutrition in COPD and to analyze the relationship between nutritional depletion and the severity of the disease. A significant inverse relationship was found between PaCO2 and body weight; a parallel decrease of both somatic proteins and body-energy stores of fat appears to be paired with decreasing body weight. Deterioration of nutritional status occurred in the COPD patients considered despite seemingly adequate calorie and protein intakes, although in patients with more severe impairment of pulmonary gas exchange, calorie intake was significantly lower compared with basal energy expenditure.

Muscle and serum magnesium in pulmonary intensive care unit patients.

Muscle specimens by means of quadriceps femoris needle biopsy and blood samples were obtained in 32 patients consecutively admitted to a pulmonary ICU for chronic obstructive pulmonary disease and acute respiratory failure, and in 30 age and sex-matched healthy control subjects. Muscle magnesium (Mg) and potassium (K) content was assessed by atomic absorption spectrophotometry; serum electrolytes were also measured. The presence of clinical and biochemical correlates of low serum and muscle Mg was investigated.

Cell metabolism response to cardiopulmonary bypass in patients undergoing aorto-coronary grafting.

The main parameters of muscle acid-base, water and energy metabolism were studied in ten patients undergoing low-flux (1.5 l/min/m2), low-pressure (40 to 60 mmHg) hypothermic (26 degrees C) cardiopulmonary bypass (CPB) for aortocoronary grafting; absolute gas exchange and haemodynamic data were also measured throughout the entire CPB period. At the end of CPB a substantial preservation of water and energy metabolic indexes was found; a condition of extracellular metabolic acidosis was apparently sustained by muscle cell anaerobic glycolysis enhancement with a consequent increase of both muscle and plasma lactate content.

Skeletal muscle energetics, acid-base equilibrium and lactate metabolism in patients with severe hypercapnia and hypoxemia.

Quadriceps femoris muscle needle biopsies were performed in ten patients with chronic obstructive pulmonary disease and acute respiratory failure and in ten age- and sex-matched healthy control subjects. The main indices of skeletal muscle cell energy metabolism, intracellular acid-base equilibrium and lactate metabolism were evaluated. Reduced ATP and phosphocreatine content, intracellular acidosis related to hypercapnia, increased muscle lactate without alterations of the muscle lactate concentration gradient were observed in the skeletal muscle of the hypercapnic-hypoxemic COPD patients studied, in which group no correlation was found between hypoxia and energy or lactate metabolism parameters.

Intracellular acid-base and electrolyte metabolism in skeletal muscle of patients with chronic obstructive lung disease and acute respiratory failure.

Quadriceps femoris muscle needle biopsies were performed in 21 patients with chronic obstructive lung disease (COLD) and acute respiratory failure (ARF) and in 21 age-matched healthy control subjects. Muscle samples were analysed to obtain intracellular bicarbonate and pH values from total acid-labile carbon dioxide content. Muscle potassium, magnesium and sodium content were also determined, as well as water compartments.

Muscle energy metabolism in uremia.

Energy-rich phosphagens were measured in 11 patients with end-stage chronic renal failure and 11 nonuremic subjects. A significant decrease of ATP, phosphocreatine, total adenine nucleotides, lactate, and energy charge was found. The present results can be referred both to glycolytic sequence disturbances and to the lack of substrates characteristic of uremia.

Uremic acidosis and intracellular buffering.

Skeletal muscle biopsies were performed in 16 controls and 15 non-dialysed end-stage chronic renal failure (CRF) patients presenting untreated metabolic acidosis. Intracellular bicarbonate, pH, water compartments and electrolytes were determined. In 8 of 15 patients muscle ATP and lactate were measured.

Intracellular bicarbonate and pH of skeletal muscle in chronic renal failure.

In 11 controls and 10 patients suffering from untreated uraemic acidosis intracellular bicarbonate and skeletal muscle pH (needle biopsy) were determined. In all patients a significant intracellular acidosis, not related to any extracellular indices was found. It is concluded that the chronic proton load is able to effect intracellular buffer composition; moreover the action of other factors such as derangements of cell metabolism and nutritional imbalance could be operating.

[Measurement of intracellular bicarbonate and pH: preliminary study using potentiometric determination of muscle acid-labile CO2].

A method is described for the determination of total acid-labile CO2 (TCO2) and intracellular bicarbonate concentration [HCO3-] in skeletal muscle samples. Surgical biopsies obtained from the quadriceps femoris muscle of 24 Wistar male rats were analyzed for acid-labile CO2 and extra and intracellular water, extracellular water was estimated from the muscle chloride content. TCO2 method utilizes a single diffusion step with absorption of extracted CO2 by sulphuric acid into barium hydroxide and subsequent potentiometric determination of muscle CO2 content.