Biomedical subjects

William L Whittier

Publications and source records attributed to William L Whittier.

4 recordsLinked to original sources

PubMed2005

The elderly patient with chronic kidney disease.

The elderly are a fast growing population in the United States, and they have a high prevalence of chronic kidney disease. The elderly are particularly susceptible to kidney damage from age-related declines in glomerular filtration as well as kidney damage from chronic disease states such as diabetes mellitus, hypertension, glomerular, and tubulointerstitial disorders. A significant number of elderly individuals are reaching end-stage renal disease that require renal replacement therapy. This expanding population provides a challenge for health-care providers because the elderly are often referred late to a nephrologist, have a shortened survival on renal replacement therapy as compared with younger individuals, and suffer from more comorbidities such as cardiovascular disease, malnutrition, and hearing and visual disabilities. The elderly also have difficulties with dialysis vascular access and often are not candidates for renal transplantation. Despite these obstacles, age alone is not a justification for withholding diagnostic or therapeutic interventions, because many elderly individuals have an improvement in their quality of life and social support once their kidney disease is identified and treated.

Age Factors↗

PubMed2004

Primer on clinical acid-base problem solving.

Acid-base problem solving has been an integral part of medical practice in recent generations. Diseases discovered in the last 30-plus years, for example, Bartter syndrome and Gitelman syndrome, D-lactic acidosis, and bulimia nervosa, can be diagnosed according to characteristic acid-base findings. Accuracy in acid-base problem solving is a direct result of a reproducible, systematic approach to arterial pH, partial pressure of carbon dioxide, bicarbonate concentration, and electrolytes. The 'Rules of Five' is one tool that enables clinicians to determine the cause of simple and complex disorders, even triple acid-base disturbances, with consistency. In addition, other electrolyte abnormalities that accompany acid-base disorders, such as hypokalemia, can be incorporated into algorithms that complement the Rules and contribute to efficient problem solving in a wide variety of diseases. Recently urine electrolytes have also assisted clinicians in further characterizing select disturbances. Acid-base patterns, in many ways, can serve as a 'common diagnostic pathway' shared by all subspecialties in medicine. From infectious disease (eg, lactic acidemia with highly active antiviral therapy therapy) through endocrinology (eg, Conn's syndrome, high urine chloride alkalemia) to the interface between primary care and psychiatry (eg, bulimia nervosa with multiple potential acid-base disturbances), acid-base problem solving is the key to unlocking otherwise unrelated diagnoses. Inasmuch as the Rules are clinical tools, they are applied throughout this monograph to diverse pathologic conditions typical in contemporary practice.

Acid-Base Equilibrium↗

PubMed2004

Renal biopsy: update.

PURPOSE OF REVIEW: The renal biopsy is an invaluable tool in the diagnosis, prognosis, and management of patients with kidney disease. As the success of the procedure is defined not only by the ability to obtain adequate tissue but also by the safety profile, significant advances which define risk factors and determine the optimal timing of observation after the percutaneous native renal biopsy merit discussion. Alternative methods of obtaining tissue, such as transvenous renal biopsies, have also been described, especially in patients with contraindications to the percutaneous method. RECENT FINDINGS: The percutaneous renal biopsy has been established as a safe and effective method of obtaining renal parenchyma. Complications, although rare, may occur and the majority of these are related to bleeding. The optimal timing of observation after the biopsy should be determined by when most complications occur, and, as over 33% of complications occur after 8 h, an observation period of at least 24 h is recommended. In patients with contraindications to the percutaneous approach, such as failure of adequate radiologic visualization or a bleeding diathesis, alternative methods of obtaining tissue have been attempted. These include open, laparascopic, transurethral, or transvenous renal biopsy. SUMMARY: Without contraindications, the percutaneous renal biopsy remains the standard method of acquiring renal tissue. At least 24 h of observation is recommended after the percutaneous native kidney biopsy for the development of potential complications. When a contraindication to the procedure exists, other methods of renal biopsy by experienced physicians may be attempted.

Biopsy↗

PubMed2004

Timing of complications in percutaneous renal biopsy.

Percutaneous renal biopsy (PRB) is a safe and effective tool in the diagnosis and management of renal disease; however, the optimal timing of observation after biopsy is not clearly established. With the use of real-time ultrasound guidance, PRB of native kidneys was performed in 750 adult patients at an academic institution by an attending nephrologist or fellow between June 1983 and June 2002. All patients were observed for 23 to 24 h after biopsy for the presence, severity, and timing of complications. Biopsy-related complications occurred in 98 (13%) patients; minor complications occurred in 50 (6.6%) patients, and major complications occurred in 48 (6.4%) patients. One (0.1%) patient died as a result of the biopsy. Multivariate analysis using logistic regression found only serum creatinine at baseline predictive of a complication. Patients with a serum creatinine > or = 5.0 mg/dl were 2.3 times as likely to have a complication (odds ratio, 2.3; 95% confidence interval, 1.3 to 4.1; P < 0.005). Complications were identified in 38 (42%) patients by < or = 4 h, in 61 (67%) patients by < or = 8 h, in 77 (85%) patients by < or = 12 h, and in 81 (89%) patients at < or = 24 h. The PRB remains a safe procedure, but the risk of complication is higher in patients with advanced renal insufficiency. After biopsy, an observation time of up to 24 h remains optimal as an observation period of < or = 8 h risks missing > or = 33% of complications.

Adult↗