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Biomedical subjects

L Velásquez-Jones

Publications and source records attributed to L Velásquez-Jones.

At least 19 recordsLinked to original sources
PubMed1997

Usefulness of fractional excretion of sodium in critically ill pre-term newborns.

The purpose of this prospective study was to measure the fractional excretion of sodium (FENa) in critically ill pre-term newborns (PTNB) in order to determine its cut point in the diagnosis of acute renal failure (ARF). This study included 52 newborns and was conducted from May, 1994 to May, 1995. Patients were divided in two groups: patients without ARF in group A (n = 47) and patients with ARF in group B (n = 5). No statistically significant differences were found in birth weight, extrauterine life span, serum sodium levels, urine creatinine and urinary volumes between the two groups, but there was a difference in gestational age, urinary sodium concentration and serum creatinine levels. Sensitivity and specificity were determined, and the critical level of FENa was 4% or greater for ARF diagnosis. The average FENa value for Group A was 1.4 +/- 1.4% with a median of 0.92%. In Group B, average FENa was 6.9 +/- 2.9% with a median of 8.5% (P < 0.001). We conclude that FENa is a valuable tool for the assessment of renal function in critically-ill PTNB, in spite of all other factors present in this population that could modify its values.

Acute Kidney Injury↗
PubMed1993

[Acute renal insufficiency].

The incidence of acute renal failure in children is higher due to the prevalence of diarrheal dehydration, use of nephrotoxic substances and sepsis. The occurrence in the newborn has increased, probably due to the large number of seriously sick infants maintained in neonatal intensive care units. Various laboratory examinations have been proposed as diagnostic indices of acute renal failure in children. Among these are the urine-to-plasma concentrations of urea and creatinine and the urine-to-plasma osmolality ratio. The fractional excretion of sodium and the so-called renal failure index are the most reliable of the diagnostic tests. The functional abnormalities and complications of acute renal failure include reduced glomerular filtration rate, retention of nitrogenous wastes, hyponatremia, hyperkalemia, metabolic acidosis, hypocalcemia, hyperphosphatemia and hypermagnesemia. The principles of management and treatment of complications are discussed.

Acute Kidney Injury↗
PubMed1992

[Nephrotic syndrome associated with AIDS in children].

Several renal and renal-related disturbances have been described in patients with AIDS (acquired immune deficiency syndrome), in adults and children as well. These are mainly electrolyte and acid-base imbalance, acute renal failure and nephrotic syndrome. The latter is usually steroid non-responder. The renal histopathological lesions described more commonly are minimal change, mesangial hyperplasia and focal segmental glomerulosclerosis. Herein, we describe a 5 year-old with AIDS, that developed nephrotic syndrome, characterized by edema, ascites, hypoalbuminemia and massive proteinuria. A percutaneous renal biopsy showed mesangial proliferation. She did not respond to a 6 week treatment with prednisone. She died with sepsis after several viral and bacterial infections.

AIDS-Associated Nephropathy↗
PubMed1992

[IgA nephropathy (Berger's disease) in children].

IgA nephropathy, also called Berger's disease, is characterized by recurrent gross hematuria or persistent microscopic hematuria, together with mesangial glomerular deposits of IgA found in the renal biopsy. Seven children with IgA nephropathy were studied. Most of them presented initially with recurrent macroscopic hematuria and low or moderate-grade proteinuria, without hypertension or renal function impairment. Only one patient presented with a rapidly progressive glomerulonephritis. Four patients did not receive any treatment; one of them is in remission, one has improved and two remain with moderate proteinuria and hematuria. One patient with significant proteinuria improved after prednisone and azathioprine treatment. The patient with rapidly progressive glomerulonephritis improved his renal function after oral prednisone and intravenous boluses of methylprednisolone and cyclophosphamide.

Adolescent↗
PubMed1992

[Acute kidney failure due to stings by Africanized bees].

Africanized bees are unique in their aggressive behavior, characterized by massive attacks during which the victims are injected an important amount of venom. For this reason, Africanized bees are extremely dangerous. Their venom contains biological toxic substances, mainly mellitin, phospholipases, histamine, hyaluronidase and apamin. Non-sensitized persons that survive a massive attack may develop acute renal failure, as a consequence of the severe hemolysis, rhabdomyolysis and shock. These complications may lead to acute renal tubular necrosis. Also, the clinical pattern and treatment of the acute renal failure secondary to bee stings are discussed.

Acute Kidney Injury↗
PubMed1991

Rice solution and World Health Organization solution by gastric infusion for high stool output diarrhea.

We sought to determine the efficacy of three different types of treatment in children with acute diarrhea who, during the oral rehydration period, had high stool output (greater than 10 mL/kg per hour). Sixty-six children, aged 1 to 18 months, with an average stool output of 22.6 mL/kg per hour were randomly distributed into three groups: group 1 received a rice flour solution, group 2 received the World Health Organization rehydration solution by gastric infusion, and group 3 continued to receive this solution orally. In all three groups, a decrease in stool output was observed, with the higher decrease observed in group 1 patients. Such a decrease facilitated rehydration of all 22 patients in group 1 (100%) in 3.3 +/- 1.5 hours, 16 (73%) in group 2 in 4.3 +/- 2.1 hours, and 15 (69%) in group 3 in 4.9 +/- 2.0 hours. No complications were observed. These data indicate that the rice flour solution is effective in children with high stool output diarrhea.

Administration, Oral↗
PubMed1990

[Water-electrolyte and acid-base disorders. V. Acid-base balance].

Disturbances of acid-base homeostasis are frequently associated with many commonly observed disease states. Recognition of abnormal plasma acid-base composition may often direct the clinician to the diagnosis of a specific disease. Simply stated, external hydrogen ion balance exits when the net hydrogen ion production from cellular metabolism equals the net hydrogen ion excretion from the body. Net cellular production of hydrogen ions consist of two components: carbonic acid, which is excreted by the lungs as CO2, and fixed acids, which require renal excretion. The net amount of fixed acid production is determined by cellular metabolism, dietary intake and gut absorption of available base equivalents. The immediate defense of pH is provided by the buffering systems, which also act as transporters of the acid from sites of production to sites of elimination. CO2 exchange by the lungs is responsible for the bulk of acid excretion: more than 99.5 percent of the normal daily acid load and 100 percent of CO2 produced by metabolism are eliminated by this route. On the other hand, the kidney is the only organ capable of excreting an appreciable quantity of fixed acid as titratable acids an ammonium, with the regeneration of bicarbonate buffer. Acid-base; buffering systems; acid-base regulation.

Acid-Base Equilibrium↗
PubMed1990

[Water-electrolyte and acid-base disorders. VIII. Respiratory acidosis].

Acute respiratory acidosis will result from many processes that acutely interfere with the excretion of CO2 by the lungs. CO2 excretion by the lungs can be interfered with by processes that inappropriately decrease minute ventilation, processes that impair the transport of CO2 from the site of production to the lungs for export, and by processes that impair the transfer of CO2 from the blood through the alveolar space to the atmosphere. The underlying clinical syndrome generating the primary hypercapnia will determine the duration of the acidosis as well as the anticipated clinical manifestations attributable to the acidosis.

Acidosis, Respiratory↗
PubMed1990

[Water-electrolyte and acid-base imbalance. VI. Metabolic acidosis].

Metabolic acidosis results from a disequilibrium between production and excretion of acid. Loss of base from the body through the gastrointestinal tract or in the urine or an increase in metabolic acid production are the three major mechanisms from which metabolic acidosis is generated. Uncomplicated metabolic acidosis is manifested by an increase in blood acidity, hypobicarbonatemia, and hypocapnea. The magnitude of these changes defines the severity wf the acidosis. It is convenient to divide metabolic acidosis into two general categories (hyperchloremic and normochloremic), based on the observed anion gap, as this serves to narrow the differential diagnosis. The normal anion gap is that amount of plasma anion not measure by routine laboratory screening that accounts for the difference between the measured sodium cation (Na+) and anions (Cl +/- HCO3-). Metabolic acidosis; causes; diagnosis; clinical manifestations.

Acid-Base Imbalance↗
PubMed1990

[Water-electrolyte and acid-base disorders. VII. Metabolic alkalosis].

Metabolic alkalosis is defined as a primary increase in plasma bicarbonate concentration. As a consequence of this increase, systemic alkalemia and secondary hypercapnia develop. In most instances metabolic alkalosis arises from loss of acid through the kidney or gastrointestinal tract. The causes of metabolic alkalosis can be separated into two groups. Those forms of alkalosis responsive to chloride salt administration (e.g., vomiting), are associated with extracellular fluid volume and chloride depletion. In contrast, alkalosis resistant to administration of chloride salt (e.g., primary aldosteronism), is usually associated with extracellular fluid volume expansion and a urine chloride above 20 mEq/L (mmol/L). Metabolic alkalosis; causes; diagnosis; clinical manifestations.

Alkalosis↗
PubMed1990

[Oral rehydration in newborns with dehydration caused by diarrhea].

The clinical experience obtained while treating 43 dehydrated newborns due to diarrhea with oral rehydration solution (ORS) using the formula recommended by the World Health Organization is reported. Of the 43 patients, 26 were severely dehydrated (greater than equal to 10% of weight recovery once rehydrated). The averaged time need to correct the dehydration was 4.7 +/- 2.7 hours, with a average intake of ORS of 26.5 +/- 7.5 mL/kg/hour. Children who were being breastfed continued so during the rehydration period. Two of the patients were hospitalized for intravenous treatment, one was due to persistent vomiting during rehydration and probably due to sepsis, and the other due to necrosing enterocolitis. The oral rehydration therapy was successful in 95% of the newborns included in the study, which proved the method to be safe and adequate for the correction of dehydration due to diarrhea among these patients. Similar experiences are reported in Mexico as well as from other countries, which also suggest the use of this therapeutic procedure in children of this age.

Dehydration↗
PubMed1990

[Comparative study of 2 oral rehydration solutions containing 60 or 90 mmol/L of sodium and with different osmolalities].

A total of 186 infants, suffering from acute diarrhea were studied and divided into two groups: 84 children were placed in group A and given the ORS recommended by the World Health Organization which contains sodium and glucose at concentrations of 60 and 90 mmol/L respectively and an osmolality of 311 mOsm/kg (mmol/kg) (ORS-90). Group B included 82 children who received an ORS containing sodium and glucose at concentrations of 60 and 90 mmol/L respectively and with an osmolality of 240 mOsm/kg (mmol/kg) (ORS-60). Seven belonging to group A (8.3%) required intravenous rehydration due to the severity of the diarrhea (three cases), persistent vomiting (three cases) and paralytic ileus (one case), while only two cases belonging to group B (2.5%) required intravenous rehydration due to severe losses through feces (one case) and another due to paralytic ileus (one case). No differences were observed due to the variations in sodium concentrations among either of the groups of patients, whether that be in the natremias when admitted or once rehydrated, with a general tendency towards the correction of the hypernatremia or hyponatremia seen during admittance with both types of ORS. A similar situation was observed with the variations in serum potassium. The results obtained from this study show the different advantages of using an ORS with lesser sodium and glucose concentrations as well as minor osmolality with those from using the solution recommended by the World Health Organization, when a lesser index of failures is observed in the treatment of children with acute diarrhea with oral rehydration therapy. Yet before widely recommending its' use, it should be demonstrated that the new ORS induces lesser losses through feces during the rehydrating period in children dehydrated due to acute diarrhea.

Chemistry, Pharmaceutical↗
PubMed1990

[Water-electrolyte and acid-base imbalance. IX. Respiratory alkalosis].

Respiratory alkalosis is the consequence of primary hypocapnia of divergent etiologies. Any pathologic process that increases ventilation to levels beyond that required to excrete the CO2 byproduct of metabolism, will result in an inappropriately low systemic pCO2 and a tendency to an alkaline systemic pH. The increased drive to ventilation may be due predominantly to a primary increase in central nervous system activity, either within the respiratory center itself or from more centrally placed areas with neural projections that extend to and control the respiratory center. Alternatively, an increased drive to ventilation may result from an "appropriate" physiologic response to another more important stimulus that overrides the human's needs to protect pCO2 and pH. Hypoxia (of different causes), is the most important and most commonly encountered such stimulus.

Alkalosis, Respiratory↗
PubMed1990

[Oral rehydration solutions with 60 or 90 nmol/L of sodium for infants with acute diarrhea in accord with their nutritional status].

A total of 186 infants suffering from dehydration due to acute diarrhea were studied and divided into two groups: 84 children were placed in group A and received the oral rehydration solution (ORS) recommended by the World Health Organization (WHO), know as ORS-90 and those placed in group B were given an ORS with 60 and 90 mmol/L of sodium and glucose, respectively, with an osmolality of 240 mOsm/kg (ORS-60). Seven patients from group A (8.3%) and two from group B (2.5%) could not be orally rehydrated and required intravenous rehydration. The children were divided according to their weight for their age into eutrophics, grade I malnutrition (10 to 25% deficit), grade II (26 to 40% deficit) and grade III (more than 40% deficit). In those patients who evolved favorably, the average rehydration time was 4.5 to 5.3 hours, independently from their nutritional state. In the same way, no important variations were seen in the average sodium and potassium serum levels once the dehydration was corrected, in either of the groups. Yet, both groups showed a persistence in hypokalemia and hyperkalemia seen when admitted, once the dehydration was corrected, demonstrating that the short time needed for the correction of the dehydration was insufficient to completely corrected the changes in serum potassium. Closer studies must be conducted on the hydric balance to adequately demonstrate if the new ORS-60 induces lesser losses through vomiting and feces when compared to the ORS-90 recommended by the WHO.

Acute Disease↗