Acute Phosphate Nephropathy after Colonoscopy
Preparation for colonoscopy may involve the administration of an oral phosphate solution, which can result in acute hyperphosphatemia and hyperphosphaturia. (Note that the Food and Drug Administration issued a warning about the potential for acute renal failure after ingestion of such solutions in 2006.) A patient with baseline impairment of kidney function undergoing this “prep” may have volume contraction due to related decreased oral intake, diarrhea or vomiting, or both or may develop acute phosphate nephropathy because of diffuse intratubular injury from calcium-phosphate deposition, given the high phosphate intake from the preparation itself. The other risk factors for acute phosphate nephropathy include preexisting kidney disease, hypertension, advanced age, female sex, antecedent volume depletion, and use of angiotensin-converting–enzyme inhibitors or angiotensin-receptor blockers, diuretics, or nonsteroidal anti-inflammatory drugs.
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
2008年8月29日 星期五
Azotemia
What guidelines may distinguish acute tubular necrosis from prerenal azotemia?
Ans: In acute tubular necrosis, the fractional excretion of sodium (FENa) is >2, the fractional excretion of urea nitrogen is >50, the urinary sodium is >20 mmol/liter, and the ratio of urinary creatinine to plasma creatinine is <15.
In contrast, in prerenal azotemia, the fractional excretion of sodium (FENa) is <1,>20.
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
Ans: In acute tubular necrosis, the fractional excretion of sodium (FENa) is >2, the fractional excretion of urea nitrogen is >50, the urinary sodium is >20 mmol/liter, and the ratio of urinary creatinine to plasma creatinine is <15.
In contrast, in prerenal azotemia, the fractional excretion of sodium (FENa) is <1,>20.
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
Pancreatitis Definition
There is a tendency to overdiagnose acute pancreatitis. A reasonable threshold for a diagnosis of acute pancreatitis is a serum level of amylase (or lipase) that is at least three times the upper limit of the normal range, plus a history of characteristic abdominal pain. If amylase (or lipase) does not reach this threshold, it is best not to make the diagnosis of acute pancreatitis unless findings on computed tomography or MRI reveal characteristic changes of acute pancreatitis.
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
UGI bleeding - rebleeding
Repeat Endoscopy
Repeat endoscopy may be considered on a case-by-case basis if there are clinical signs of recurrent bleeding or if there is uncertainty regarding the effectiveness of hemostasis during the initial treatment. However, planned second-look endoscopy that is performed within 24 hours after initial endoscopic therapy is generally not recommended. Even though such a procedure was shown to be efficacious in two meta-analyses, it provided only a limited reduction in the rate of rebleeding. Also, the procedure may not be cost-effective when medical therapy leading to profound acid suppression is initiated.
What test should be included in the long-term management and treatment of patients after acute peptic ulcer bleeding?
Ans: Testing for and treatment of H. pylori infection are critical considerations in the long-term management and treatment of patients after acute peptic ulcer bleeding.
What is the precise definition of postural changes or orthostatic hypotension?
Ans: Postural changes or orthostatic hypotension is defined as an increase in the pulse of ≥20 or more beats per minute or a drop in systolic blood pressure of over 20 mm Hg on standing after the patient has been in a recumbent position for at least five minutes.
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
Repeat endoscopy may be considered on a case-by-case basis if there are clinical signs of recurrent bleeding or if there is uncertainty regarding the effectiveness of hemostasis during the initial treatment. However, planned second-look endoscopy that is performed within 24 hours after initial endoscopic therapy is generally not recommended. Even though such a procedure was shown to be efficacious in two meta-analyses, it provided only a limited reduction in the rate of rebleeding. Also, the procedure may not be cost-effective when medical therapy leading to profound acid suppression is initiated.
What test should be included in the long-term management and treatment of patients after acute peptic ulcer bleeding?
Ans: Testing for and treatment of H. pylori infection are critical considerations in the long-term management and treatment of patients after acute peptic ulcer bleeding.
What is the precise definition of postural changes or orthostatic hypotension?
Ans: Postural changes or orthostatic hypotension is defined as an increase in the pulse of ≥20 or more beats per minute or a drop in systolic blood pressure of over 20 mm Hg on standing after the patient has been in a recumbent position for at least five minutes.
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
UGI bleeding
Acute Upper Gastrointestinal Bleeding
The mortality associated with acute bleeding from a peptic ulcer remains high (5 to 10%), and the condition accounts for more than 400,000 hospital admissions per year in the United States. In most settings, the vast majority of acute episodes of upper gastrointestinal bleeding (80 to 90%) have nonvariceal causes, with gastroduodenal peptic ulcer accounting for the majority of lesions.
Nasogastric Tube
The insertion of a nasogastric tube may be helpful in the initial assessment of the patient (specifically, triage), although the incremental information such a procedure provides remains controversial. It has been suggested that the presence of blood in the nasogastric aspirate is an adverse prognostic sign that may be useful in identifying patients who require urgent endoscopic evaluation. However, the absence of bloody or coffee-ground material does not definitively rule out ongoing or recurrent bleeding, since approximately 15% of patients without bloody or coffee-ground material in nasogastric aspirates are found to have high-risk lesions on endoscopy. The use of a large-bore orogastric tube with gastric lavage (with the use of tap water at room temperature) appears to improve only the visualization of the gastric fundus on endoscopy and has not been documented to improve outcome.
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
The mortality associated with acute bleeding from a peptic ulcer remains high (5 to 10%), and the condition accounts for more than 400,000 hospital admissions per year in the United States. In most settings, the vast majority of acute episodes of upper gastrointestinal bleeding (80 to 90%) have nonvariceal causes, with gastroduodenal peptic ulcer accounting for the majority of lesions.
Nasogastric Tube
The insertion of a nasogastric tube may be helpful in the initial assessment of the patient (specifically, triage), although the incremental information such a procedure provides remains controversial. It has been suggested that the presence of blood in the nasogastric aspirate is an adverse prognostic sign that may be useful in identifying patients who require urgent endoscopic evaluation. However, the absence of bloody or coffee-ground material does not definitively rule out ongoing or recurrent bleeding, since approximately 15% of patients without bloody or coffee-ground material in nasogastric aspirates are found to have high-risk lesions on endoscopy. The use of a large-bore orogastric tube with gastric lavage (with the use of tap water at room temperature) appears to improve only the visualization of the gastric fundus on endoscopy and has not been documented to improve outcome.
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New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008
Beware antipsychotics in dementia
Almost everyone with dementia has behavioural and psychiatric problems such as depression, agitation or delusions at some stage. They are often prescribed antipsychotic drugs to control their symptoms. Atypical antipsychotics (e.g. risperidone, olanzpine) increase the risk of death by 8% in a year compared with non-antipsychotic medication. The reason may be a direct effect of the drugs or that the disease that causes the symptoms also causes early death. Non drug treatments like behavioural therapy should be considered, say the authors.
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Source: Evidence-Based Mental Health 2008;11:73. Abstracted from Am J Psychiatry 2007;164:1568-76.
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Source: Evidence-Based Mental Health 2008;11:73. Abstracted from Am J Psychiatry 2007;164:1568-76.
Dangerous Sports
People across the world have been watching the Olympics this month, and many will be encouraged to do more sport. But no activity is completely risk-free, as this 10 year retrospective study of sports-related deaths points out. It notes that:
Source: British Journal of Sports Medicine 2008;42:604-608
- Sudden death most often happens in people with left ventricular hypertrophy from underlying coronary heart disease
- Traumatic deaths from drowning or blunt trauma most often happen on holiday in unfamiliar surroundings
- Medical screening for everyone before participation in sports won't prevent many of the unexpected death
- The cause is often not apparent until a postmortem is carried out
Source: British Journal of Sports Medicine 2008;42:604-608
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