Oliguria as predictive biomarker of acute kidney injury in critically ill patients

INTRODUCTION

During critical illness, oliguria is often used as a biomarker of acute kidney injury (AKI). However, its relationship with the subsequent development of AKI has not been prospectively evaluated.

METHODS

We documented urine output and daily serum creatinine concentration in patients admitted for more than 24 hours in seven intensive care units (ICUs) from six countries over a period of two to four weeks. Oliguria was defined by a urine output < 0.5 ml/kg/hr. Data were collected until the occurrence of creatinine-defined AKI (AKI-Cr), designated by RIFLE-Injury class or greater using creatinine criteria (RIFLE-I[Cr]), or until ICU discharge. Episodes of oliguria were classified by longest duration of consecutive oliguria during each day were correlated with new AKI-Cr the next day, examining cut-offs for oliguria of greater than 1,2,3,4,5,6, or 12 hr duration,

RESULTS

We studied 239 patients during 723 days. Overall, 32 patients had AKI on ICU admission, while in 23, AKI-Cr developed in ICU. Oliguria of greater than one hour was significantly associated with AKI-Cr the next day. On receiver-operator characteristic area under the curve (ROCAUC) analysis, oliguria showed fair predictive ability for AKI-Cr (ROCAUC = 0.75; CI:0.64-0.85). The presence of 4 hrs or more oliguria provided the best discrimination (sensitivity 52% (0.31-0.73%), specificity 86% (0.84-0.89%), positive likelihood ratio 3.8 (2.2-5.6), P < 0.0001) with negative predictive value of 98% (0.97-0.99). Oliguria preceding AKI-Cr was more likely to be associated with lower blood pressure, higher heart rate and use of vasopressors or inotropes and was more likely to prompt clinical intervention. However, only 30 of 487 individual episodes of oliguria preceded the new occurrence of AKI-Cr the next day.

CONCLUSIONS

Oliguria was significantly associated with the occurrence of new AKI-Cr, however oliguria occurred frequently compared to the small number of patients (~10%) developing AKI-Cr in the ICU, so that most episodes of oliguria were not followed by renal injury. Consequently, the occurrence of short periods (1-6 hr) of oliguria lacked utility in discriminating patients with incipient AKI-Cr (positive likelihood ratios of 2-4, with > 10 considered indicative of a useful screening test). However, oliguria accompanied by hemodynamic compromise or increasing vasopressor dose may represent a clinically useful trigger for other early biomarkers of renal injury.

Epidemic of pediatric deaths from acute renal failure caused by diethylene glycol poisoning. Acute Renal Failure Investigation Team

CONTEXT

Contaminated pharmaceutical products can result in substantial morbidity and mortality and should be included in the differential diagnosis of deaths of unknown origin.

OBJECTIVE

To investigate an outbreak of deaths among children from acute renal failure in Haiti to determine the etiology and institute control measures.

DESIGN

Case-control study, cohort study, and laboratory toxicologic evaluation.

SETTING

Pediatric population of Haiti.

PARTICIPANTS

Cases were defined as Haitian residents younger than 18 years with idiopathic anuria or severe oliguria for 24 hours or longer. Febrile hospitalized children without renal failure were enrolled as control subjects.

MAIN OUTCOME MEASURE

The odds of exposure to suspected etiologic agents among cases and controls.

RESULTS

We identified 109 cases of acute renal failure among children. The clinical syndrome included renal failure, hepatitis, pancreatitis, central nervous system impairment, coma, and death. Of 87 patients with follow-up information who remained in Haiti for treatment, 85 (98%) died; 3 (27%) of 11 patients transported to the United States for intensive care unit management died before hospital discharge. A locally manufactured acetaminophen syrup was highly associated with disease (odds ratio, 52.7; 95% confidence interval, 15.2-197.2). Diethylene glycol (DEG) was found in patients' bottles in a median concentration of 14.4%. The median estimated toxic dose of DEG was 1.34 mL/kg (range, 0.22-4.42 mL/kg). Glycerin, a raw material imported to Haiti and used in the acetaminophen formulation, was contaminated with 24% DEG.

CONCLUSIONS

An epidemic of severe systemic toxicity and deaths from DEG-contaminated acetaminophen syrup occurred in Haiti. Good manufacturing practice regulations should be used by all pharmaceutical manufacturers to prevent such tragedies.

Nonoliguric hyperkalemia in the premature infant weighing less than 1000 grams

Eighteen very low birth weight premature infants born before 28 weeks gestation and weighing less than 1000 gm were evaluated prospectively for disturbances in serum electrolyte concentrations and for renal glomerular and tubular functions. Clinically symptomatic hyperkalemia resulting in significant electrocardiographic dysrhythmias developed in eight of these infants; 10 babies remained normokalemic. Peak serum potassium concentration ranged from 6.9 to 9.2 mEq/L in the hyperkalemic group; all potassium values in the normokalemic group were less than 6.6 mEq/L. Indices of renal glomerular function and urine output were similar in both groups; no infant had oliguria. Serum creatinine concentrations were the same in both groups (1.04 +/- 0.16 SD mg/dl in normokalemic vs 1.19 +/- 0.24 mg/dl in hyperkalemic infants, beta less than 0.2 at alpha = 0.05), and glomerular filtration rates did not differ significantly (6.29 +/- 1.78 ml/min/1.73 m2 in normokalemic vs 5.70 +/- 1.94 ml/min/1.73 m2 in hyperkalemic infants, beta less than 0.2 at alpha = 0.05). In contrast, indicators of tubular function revealed a significantly larger fractional excretion of sodium in hyperkalemic infants: 13.9 +/- 5.4% versus 5.6 +/- 0.9% in normokalemic control subjects (p less than 0.001). Hyperkalemic infants also had a tendency toward lower urine concentrations of potassium, although there was no significant difference in their net potassium excretion in comparison with that in the normokalemic group. We speculate that hyperkalemia in the tiny baby is in part the result of immature distal tubule function with a compromise in ability to regulate potassium balance.

Acute Interstitial Nephritis Due to Pantoprazole

OBJECTIVE:

To describe what is believed, as of November 4, 2003, to be the first case published in the literature of acute interstitial nephritis (AIN) due to pantoprazole.

CASE SUMMARY:

A 77-year-old white woman presented to the hospital with elevated serum creatinine, oliguria for the past 24 hours, arthralgia, fatigue, fever, and bilateral flank pain. The patient had initiated treatment with oral pantoprazole 40 mg/d for gastroesophageal reflux 2 months prior to admission. After 5 weeks of therapy, she stopped taking pantoprazole due to general malaise. Upon admission, all home medications, including pantoprazole, were reinitiated based on the patient's medication list. Serum creatinine increased to 6.1 mg/dL on day 4 of admission from a baseline of 1.0 mg/dL. Pantoprazole therapy was promptly discontinued, and prednisone 40 mg/d was initiated. Urinalysis revealed eosinophils, and a subsequent renal biopsy confirmed a diagnosis of AIN. The serum creatinine level gradually declined over 2 weeks, and the patient was discharged home with a serum creatinine level of 1.6 mg/dL. The Naranjo probability scale suggests a highly probable relationship between AIN and pantoprazole therapy in this patient.

DISCUSSION:

Drug hypersensitivity reactions are the most common cause of AIN. There have been several reported cases of omeprazole-induced AIN. Although there are very few prospective data on the efficacy of treatment of drug-induced AIN, corticosteroids may have a role in recovery of renal function. Prednisone doses of 1 mg/kg/d have been suggested.

CONCLUSIONS:

Physicians should be aware that drug-induced AIN can be associated with proton-pump inhibitors. Early detection of this rare adverse reaction may prevent acute renal insufficiency.

Pathogenesis of acute renal failure associated with the HELLP syndrome: a case report and review of the literature

Acute renal failure is a rare but serious complication of pregnancy. We describe a 31-year-old woman with haemolytic anemia, elevated liver enzymes, low platelets (HELLP syndrome) who developed acute peripartum renal failure. Renal biopsy performed 2 weeks later because of persistent oliguria revealed thrombotic microangiopathy and acute tubular necrosis. This case highlights the probable pathogenesis of acute renal failure in HELLP patients and explains why it resolves in the majority of cases. A review of the literature that describes renal histology in HELLP patients is presented.

Acute nonoliguric renal failure in children associated with nonsteroidal antiinflammatory agents

OBJECTIVE

Acute renal failure is commonly seen in adults after treatment with nonsteroidal antiinflammatory agents. This complication has rarely been reported in children.

DESIGN

Four consecutive patients admitted with acute nonoliguric renal failure associated with ingestion of nonsteroidal antiinflammatory agents.

SETTING

The emergency department and ward units at The Children's Hospital of Philadelphia.

PATIENTS

Four patients, ages 3.5 to 19 years.

INTERVENTIONS

Appropriate evaluations including measurement of serum creatinine concentrations in the emergency department and careful histories of drug ingestion.

MAIN OUTCOME MEASURE

Rapid return to normal serum creatinine concentrations.

RESULTS

Four patients were admitted to The Children's Hospital of Philadelphia between May 1996 and June 1997 with a diagnosis of acute, nonoliguric renal failure following ingestion of nonsteroidal antiinflammatory agents. None of the patients had features of hemolytic uremic syndrome, systemic lupus, dehydration, obstructive uropathy or sickle cell disease. Each patient had ingested nonsteroidal antiinflammatory agents before the onset of acute renal failure. None had oliguria or anuria, dehydration, abnormal serum electrolyte concentrations, or evidence of glomerulonephritis. One patient also had a urinary tract infection that was treated with antibiotics. Another patient was treated with methylprednisolone and prednisone. None was biopsied. Three recovered completely.

CONCLUSION

With the increasing use of over-the-counter nonsteroidal antiinflammatory agents, this association may become more prevalent.

Diagnosis of acute renal failure in very preterm infants

This study was designed to improve the definition of acute renal failure (ARF) in very preterm infants. Twenty-eight newborn infants with gestational age < or =32 weeks were prospectively studied in the first 5 days of life and made up a control group as they did not present risk factors for vasomotor renal insufficiency. Renal insufficiency was defined as an increase in daily serum creatinine concentration above the 99th interval limit obtained in this control group, i.e., 43 micromol/l on day 1 and/or 21 micromol/l on day 2 and/or 14 micromol/l/day on day 3 and/or 22 micromol/l/day on day 4. According to this definition, 20 very preterm infants with ARF were identified. As compared with the control group, the ARF group showed more prolonged oliguric episodes, lower diuresis, insufficient weight loss (in spite of a reduction in water intake) and also more episodes with natremia <130 mEq/l (35 vs. 0%; p <0.05) and/or kalemia >6 mEq/l (40 vs. 11%; p <0.05). Therefore, assessment of daily changes in serum creatinine concentration in very preterm infants allows the diagnosis of clinically significant reduction in glomerular filtration rate.

Management of aortic arch interruption with prostaglandin E1 infusion and microporous expanded polytetrafluoroethylene grafts

Prostaglandin E1 infusion and a microporous expanded polytetrafluoroethylene graft were used in the management of eight infants, all less than 4 days old, with interruption of the aortic arch. Five of the six infants receiving prostaglandin E1 responded dramatically to this therapy, with return of lower limb pulses and lessening of metabolic acidosis. There were no adverse effects attributable to the prostaglandin E1 infusion. Seven infants subsequently underwent aortic reconstruction with a polytetrafluoroethylene graft. There were no operative deaths, and in up to 3 years of follow-up of these patients, graft obstruction occurred in only one patient and this graft was successfully revised. The long-term mortality rate was high (62 percent); all deaths but one were attributable either to the palliation or to the total correction of the associated cardiac malformations.

Distal tubular necrosis with little or no oliguria

Images

A young man with acute renal failure and severe loin pain

The first case of exercise-induced acute renal failure (EIARF) is reported measuring the blood flow and arterial resistance in the kidney by pulsed Doppler ultrasound. A 20-year-old Japanese male suffered from severe loin pain and non-oliguric acute renal failure after strenuous exercise. Serum myoglobin and creatine phosphokinase were normal and urinary myoglobin was not detectable. The Doppler pattern in several segmental arteries showed a slow end-diastolic velocity (EV) and a high resistance index (RI), indicating increased renal vascular resistance, which suggested severe renal vasoconstriction. Three days later, the EV had apparently increased and the RI normalized in accordance with improvement of renal function. The ultrasound Doppler technique is useful for the detection of a decrease in arterial blood flow on real time and for the diagnosis of EIARF.