Louis Imbriano - Academia.edu (original) (raw)
Papers by Louis Imbriano
Journal of Vascular and Interventional Radiology, 2005
Clinical Infectious Diseases, 1994
Journal of the American Geriatrics Society, 2015
Journal of the American Geriatrics Society, 2015
Journal of Clinical Medicine, 2014
Hyponatremia is the most common electrolyte abnormality. Its diagnostic and therapeutic approache... more Hyponatremia is the most common electrolyte abnormality. Its diagnostic and therapeutic approaches are in a state of flux. It is evident that hyponatremic patients are symptomatic with a potential for serious consequences at sodium levels that were once considered trivial. The recommendation to treat virtually all hyponatremics exposes the need to resolve the diagnostic and therapeutic dilemma of deciding whether to water restrict a patient with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) or administer salt and water to a renal salt waster. In this review, we briefly discuss the pathophysiology of SIADH and renal salt wasting (RSW), and the difficulty in differentiating SIADH from RSW, and review the origin of the perceived rarity of RSW, as well as the value of determining fractional excretion of urate (FEurate) in differentiating both syndromes, the high prevalence of RSW which highlights the inadequacy of the volume approach to hyponatremia, the importance of changing cerebral salt wasting to RSW, and the proposal to eliminate reset osmostat as a subtype of SIADH, and finally propose a new algorithm to replace the outmoded volume approach by highlighting FEurate. This algorithm eliminates the need to assess the volume status with less reliance on determining urine sodium concentration, plasma renin, aldosterone and atrial/brain natriuretic peptide or the BUN to creatinine ratio.
Diabetes and Kidney Disease, 2014
ABSTRACT Diabetes mellitus is a leading cause of end stage renal failure and contributes to a dif... more ABSTRACT Diabetes mellitus is a leading cause of end stage renal failure and contributes to a diffuse arteriolopathy. Diabetic nephropathy (DN) has been typically characterized by progressive proteinuria associated with progressive renal insufficiency. However this typical pattern of DN and proteinuria may be inadequate for a complete definition of DN. While glucotoxicity has been classically considered to be the agent of renal injury, other “atypical” mediators of renal injury also contribute. In addition, the renal pathologic changes can also be atypical for a sizable population of diabetics. The dissociation of albuminuria from declining glomerular filtration rate and even from the renal pathologic changes suggests alternative mechanisms are responsible for renal injury. Diabetes could be considered a chronic inflammatory disease with nephropathy resulting from the interplay of inflammatory mediators and the immune system. There are other unusual or “atypical” associations of the kidney and diabetes, which will be discussed in this chapter.
ABSTRACT Chronic kidney disease (CKD) is present in approximately 23 % of the 24 million American... more ABSTRACT Chronic kidney disease (CKD) is present in approximately 23 % of the 24 million Americans with diabetes. In order to prevent end stage renal disease and decrease mortality in this population, the American Diabetes Association and the National Kidney Foundation have published clear evidence-based guidelines for the treatment of these patients. Despite these guidelines, patients with diabetes and CKD remain undertreated. In this chapter we will examine existing deficiencies in the treatment of patients with diabetes and CKD. We will then review recent efforts to use computerized clinical decision support to augment the treatment of these patients. Finally, we will describe characteristics of an optimal computerized clinical decision support system to treat patients with diabetes and CKD.
Seminars in Dialysis, 2003
Hyperkalemia is a frequent and dangerous problem in dialysis patients. Many factors contribute to... more Hyperkalemia is a frequent and dangerous problem in dialysis patients. Many factors contribute to potentially life-threatening potassium elevation and most remedies used to treat hyperkalemia are handicapped by the consequences of the separate pools of intra- and extracellular potassium. Besides the kidney, the colon has the ability to excrete potassium, which can help lower total body potassium. Several prior authors have addressed the colon's ability to up-regulate potassium secretion, including the effect of aldosterone on fecal potassium content. Potentially dangerous intradialytic maneuvers to lower potassium levels may be avoidable with the use of the mineralocorticoid agonist fludrocortisone.
Kidney International, 2009
Cerebral salt-wasting (CSW), or renal salt-wasting (RSW), has evolved from a misrepresentation of... more Cerebral salt-wasting (CSW), or renal salt-wasting (RSW), has evolved from a misrepresentation of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) to acceptance as a distinct entity. Challenges still confront us as we attempt to differentiate RSW from SIADH, ascertain the prevalence of RSW, and address reports of RSW occurring without cerebral disease. RSW is redefined as 'extracellular volume depletion due to a renal sodium transport abnormality with or without high urinary sodium concentration, presence of hyponatremia or cerebral disease with normal adrenal and thyroid function.' Our inability to differentiate RSW from SIADH lies in the clinical and laboratory similarities between the two syndromes and the difficulty of accurate assessment of extracellular volume. Radioisotopic determinations of extracellular volume in neurosurgical patients reveal renal that RSW is more common than SIADH. We review the persistence of hypouricemia and increased fractional excretion of urate in RSW as compared to correction of both in SIADH, the appropriateness of ADH secretion in RSW, and the importance of differentiating renal RSW from SIADH because of disparate treatment goals: fluid repletion in RSW and fluid restriction in SIADH. Patients with RSW are being incorrectly treated by fluid restriction, with clinical consequences. We conclude that RSW is common and occurs without cerebral disease, and propose changing CSW to RSW.
Kidney International, 2009
Journal of Nephrology, 2012
Reset osmostat (RO) occurs in 36% of patients with syndrome of inappropriate antidiuretic hormone... more Reset osmostat (RO) occurs in 36% of patients with syndrome of inappropriate antidiuretic hormone secretion (SIADH) and is not often considered when evaluating hyponatremic patients. Patients with RO are not usually treated, but recent awareness that symptoms are associated with mild hyponatremia creates a therapeutic dilemma. We encountered patients with hyponatremia, hypouricemia and high urine sodium concentration (UNa), who had normal fractional excretion (FE) of urate and excreted dilute urines that were consistent with RO. We decided to test whether a normal FEurate in nonedematous hyponatremia irrespective of UNa or serum urate would identify patients with RO. We determined FEurate in nonedematous hyponatremic patients. A diagnosis of RO was made if urine osmolality (Uosm) was <200 mOsm/kg in a random urine. We performed a modified water-loading test in patients with a normal FEurate whose random Uosm was >200 mOsm/kg. All nonedematous hyponatremic patients with FEurate of 4%-11% had RO, as determined by Uosm <200 mOsm/kg on a random urine collection in 8 patients, or after a modified water-loading test in 6 patients. Plasma antidiuretic hormone (ADH) in 4 patients was undetectable at <1 pg/mL during water-loading. Nine patients had baseline concentrated urine, 12 had UNa >20 mmol/L, 9 were hypouricemic, yet all had a normal FEurate. Comorbidities were similar to those reported in RO. RO, a benign form of SIADH, occurs commonly. A normal FEurate in a nonedematous hyponatremic patient is highly suggestive of RO. Determining FEurate is superior to serum urate. The therapeutic dilemma for RO must be resolved.
Clinical Journal of the American Society of Nephrology, 2009
The existence and prevalence of cerebral salt wasting (CSW) or the preferred term, renal salt was... more The existence and prevalence of cerebral salt wasting (CSW) or the preferred term, renal salt wasting (RSW), and its differentiation from syndrome of inappropriate antidiuretic hormone (SIADH) have been controversial. This controversy stems from overlapping clinical and laboratory findings and an inability to assess the volume status of these patients. The authors report another case of RSW without clinical cerebral disease and contrast it to SIADH. Three patients with hyponatremia, hypouricemia, increased fractional excretion (FE) of urate, urine sodium >20 mmol/L, and concentrated urines were infused with isotonic saline after collection of baseline data. One patient with RSW had pneumonia without cerebral disease and showed increased plasma aldosterone and FEphosphate, and two patients with SIADH had increased blood volume, low plasma renin and aldosterone, and normal FEphosphate. The patient with RSW responded to isotonic saline by excretion of dilute urines, prompt correction of hyponatremia, and normal water loading test after volume repletion. Hypouricemia and increased FEurate persisted after correction of hyponatremia. Two patients with SIADH failed to dilute their urines and remained hyponatremic during 48 and 110 h of saline infusion. The authors demonstrate appropriate stimulation of ADH in RSW. Differences in plasma renin and aldosterone levels and FEphosphate can differentiate RSW from SIADH, as will persistent hypouricemia and increased FEurate after correction of hyponatremia in RSW. FEphosphate was the only contrasting variable at baseline. The authors suggest an approach to treat the hyponatremic patient meeting criteria for SIADH and RSW and changing CSW to the more appropriate term, RSW
American Journal of Kidney Diseases, 2004
American Journal of Kidney Diseases, 2005
Autoregulation of glomerular capillary pressure via regulation of the resistances at the afferent... more Autoregulation of glomerular capillary pressure via regulation of the resistances at the afferent and efferent arterioles plays a critical role in maintaining the glomerular filtration rate over a wide range of mean arterial pressure. Angiotensin II and prostaglandins are among the agents which contribute to autoregulation and drugs which interfere with these agents may have a substantial impact on afferent and efferent arteriolar resistance. We describe a patient who suffered an episode of anuric acute kidney injury following exposure to a nonsteroidal anti-inflammatory agent while on two diuretics, an angiotensin-converting enzyme inhibitor, and an angiotensin receptor blocker. The episode completely resolved and we review some of the mechanisms by which these events may have taken place and suggest the term "acute renal autoregulatory dysfunction" to describe this syndrome.
Journal of Vascular and Interventional Radiology, 2005
Clinical Infectious Diseases, 1994
Journal of the American Geriatrics Society, 2015
Journal of the American Geriatrics Society, 2015
Journal of Clinical Medicine, 2014
Hyponatremia is the most common electrolyte abnormality. Its diagnostic and therapeutic approache... more Hyponatremia is the most common electrolyte abnormality. Its diagnostic and therapeutic approaches are in a state of flux. It is evident that hyponatremic patients are symptomatic with a potential for serious consequences at sodium levels that were once considered trivial. The recommendation to treat virtually all hyponatremics exposes the need to resolve the diagnostic and therapeutic dilemma of deciding whether to water restrict a patient with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) or administer salt and water to a renal salt waster. In this review, we briefly discuss the pathophysiology of SIADH and renal salt wasting (RSW), and the difficulty in differentiating SIADH from RSW, and review the origin of the perceived rarity of RSW, as well as the value of determining fractional excretion of urate (FEurate) in differentiating both syndromes, the high prevalence of RSW which highlights the inadequacy of the volume approach to hyponatremia, the importance of changing cerebral salt wasting to RSW, and the proposal to eliminate reset osmostat as a subtype of SIADH, and finally propose a new algorithm to replace the outmoded volume approach by highlighting FEurate. This algorithm eliminates the need to assess the volume status with less reliance on determining urine sodium concentration, plasma renin, aldosterone and atrial/brain natriuretic peptide or the BUN to creatinine ratio.
Diabetes and Kidney Disease, 2014
ABSTRACT Diabetes mellitus is a leading cause of end stage renal failure and contributes to a dif... more ABSTRACT Diabetes mellitus is a leading cause of end stage renal failure and contributes to a diffuse arteriolopathy. Diabetic nephropathy (DN) has been typically characterized by progressive proteinuria associated with progressive renal insufficiency. However this typical pattern of DN and proteinuria may be inadequate for a complete definition of DN. While glucotoxicity has been classically considered to be the agent of renal injury, other “atypical” mediators of renal injury also contribute. In addition, the renal pathologic changes can also be atypical for a sizable population of diabetics. The dissociation of albuminuria from declining glomerular filtration rate and even from the renal pathologic changes suggests alternative mechanisms are responsible for renal injury. Diabetes could be considered a chronic inflammatory disease with nephropathy resulting from the interplay of inflammatory mediators and the immune system. There are other unusual or “atypical” associations of the kidney and diabetes, which will be discussed in this chapter.
ABSTRACT Chronic kidney disease (CKD) is present in approximately 23 % of the 24 million American... more ABSTRACT Chronic kidney disease (CKD) is present in approximately 23 % of the 24 million Americans with diabetes. In order to prevent end stage renal disease and decrease mortality in this population, the American Diabetes Association and the National Kidney Foundation have published clear evidence-based guidelines for the treatment of these patients. Despite these guidelines, patients with diabetes and CKD remain undertreated. In this chapter we will examine existing deficiencies in the treatment of patients with diabetes and CKD. We will then review recent efforts to use computerized clinical decision support to augment the treatment of these patients. Finally, we will describe characteristics of an optimal computerized clinical decision support system to treat patients with diabetes and CKD.
Seminars in Dialysis, 2003
Hyperkalemia is a frequent and dangerous problem in dialysis patients. Many factors contribute to... more Hyperkalemia is a frequent and dangerous problem in dialysis patients. Many factors contribute to potentially life-threatening potassium elevation and most remedies used to treat hyperkalemia are handicapped by the consequences of the separate pools of intra- and extracellular potassium. Besides the kidney, the colon has the ability to excrete potassium, which can help lower total body potassium. Several prior authors have addressed the colon's ability to up-regulate potassium secretion, including the effect of aldosterone on fecal potassium content. Potentially dangerous intradialytic maneuvers to lower potassium levels may be avoidable with the use of the mineralocorticoid agonist fludrocortisone.
Kidney International, 2009
Cerebral salt-wasting (CSW), or renal salt-wasting (RSW), has evolved from a misrepresentation of... more Cerebral salt-wasting (CSW), or renal salt-wasting (RSW), has evolved from a misrepresentation of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) to acceptance as a distinct entity. Challenges still confront us as we attempt to differentiate RSW from SIADH, ascertain the prevalence of RSW, and address reports of RSW occurring without cerebral disease. RSW is redefined as 'extracellular volume depletion due to a renal sodium transport abnormality with or without high urinary sodium concentration, presence of hyponatremia or cerebral disease with normal adrenal and thyroid function.' Our inability to differentiate RSW from SIADH lies in the clinical and laboratory similarities between the two syndromes and the difficulty of accurate assessment of extracellular volume. Radioisotopic determinations of extracellular volume in neurosurgical patients reveal renal that RSW is more common than SIADH. We review the persistence of hypouricemia and increased fractional excretion of urate in RSW as compared to correction of both in SIADH, the appropriateness of ADH secretion in RSW, and the importance of differentiating renal RSW from SIADH because of disparate treatment goals: fluid repletion in RSW and fluid restriction in SIADH. Patients with RSW are being incorrectly treated by fluid restriction, with clinical consequences. We conclude that RSW is common and occurs without cerebral disease, and propose changing CSW to RSW.
Kidney International, 2009
Journal of Nephrology, 2012
Reset osmostat (RO) occurs in 36% of patients with syndrome of inappropriate antidiuretic hormone... more Reset osmostat (RO) occurs in 36% of patients with syndrome of inappropriate antidiuretic hormone secretion (SIADH) and is not often considered when evaluating hyponatremic patients. Patients with RO are not usually treated, but recent awareness that symptoms are associated with mild hyponatremia creates a therapeutic dilemma. We encountered patients with hyponatremia, hypouricemia and high urine sodium concentration (UNa), who had normal fractional excretion (FE) of urate and excreted dilute urines that were consistent with RO. We decided to test whether a normal FEurate in nonedematous hyponatremia irrespective of UNa or serum urate would identify patients with RO. We determined FEurate in nonedematous hyponatremic patients. A diagnosis of RO was made if urine osmolality (Uosm) was <200 mOsm/kg in a random urine. We performed a modified water-loading test in patients with a normal FEurate whose random Uosm was >200 mOsm/kg. All nonedematous hyponatremic patients with FEurate of 4%-11% had RO, as determined by Uosm <200 mOsm/kg on a random urine collection in 8 patients, or after a modified water-loading test in 6 patients. Plasma antidiuretic hormone (ADH) in 4 patients was undetectable at <1 pg/mL during water-loading. Nine patients had baseline concentrated urine, 12 had UNa >20 mmol/L, 9 were hypouricemic, yet all had a normal FEurate. Comorbidities were similar to those reported in RO. RO, a benign form of SIADH, occurs commonly. A normal FEurate in a nonedematous hyponatremic patient is highly suggestive of RO. Determining FEurate is superior to serum urate. The therapeutic dilemma for RO must be resolved.
Clinical Journal of the American Society of Nephrology, 2009
The existence and prevalence of cerebral salt wasting (CSW) or the preferred term, renal salt was... more The existence and prevalence of cerebral salt wasting (CSW) or the preferred term, renal salt wasting (RSW), and its differentiation from syndrome of inappropriate antidiuretic hormone (SIADH) have been controversial. This controversy stems from overlapping clinical and laboratory findings and an inability to assess the volume status of these patients. The authors report another case of RSW without clinical cerebral disease and contrast it to SIADH. Three patients with hyponatremia, hypouricemia, increased fractional excretion (FE) of urate, urine sodium >20 mmol/L, and concentrated urines were infused with isotonic saline after collection of baseline data. One patient with RSW had pneumonia without cerebral disease and showed increased plasma aldosterone and FEphosphate, and two patients with SIADH had increased blood volume, low plasma renin and aldosterone, and normal FEphosphate. The patient with RSW responded to isotonic saline by excretion of dilute urines, prompt correction of hyponatremia, and normal water loading test after volume repletion. Hypouricemia and increased FEurate persisted after correction of hyponatremia. Two patients with SIADH failed to dilute their urines and remained hyponatremic during 48 and 110 h of saline infusion. The authors demonstrate appropriate stimulation of ADH in RSW. Differences in plasma renin and aldosterone levels and FEphosphate can differentiate RSW from SIADH, as will persistent hypouricemia and increased FEurate after correction of hyponatremia in RSW. FEphosphate was the only contrasting variable at baseline. The authors suggest an approach to treat the hyponatremic patient meeting criteria for SIADH and RSW and changing CSW to the more appropriate term, RSW
American Journal of Kidney Diseases, 2004
American Journal of Kidney Diseases, 2005
Autoregulation of glomerular capillary pressure via regulation of the resistances at the afferent... more Autoregulation of glomerular capillary pressure via regulation of the resistances at the afferent and efferent arterioles plays a critical role in maintaining the glomerular filtration rate over a wide range of mean arterial pressure. Angiotensin II and prostaglandins are among the agents which contribute to autoregulation and drugs which interfere with these agents may have a substantial impact on afferent and efferent arteriolar resistance. We describe a patient who suffered an episode of anuric acute kidney injury following exposure to a nonsteroidal anti-inflammatory agent while on two diuretics, an angiotensin-converting enzyme inhibitor, and an angiotensin receptor blocker. The episode completely resolved and we review some of the mechanisms by which these events may have taken place and suggest the term "acute renal autoregulatory dysfunction" to describe this syndrome.