July 2008 icuroom.net Archive

2008-07-31T12:42:00.000-07:00

Thursday July 31, 2008
Salicylate overdose and "neuroglycopenia"

Salicylate cause "neuroglycopenia" (lower CNS glucose level) despite normal serum glucose. As patient gets more and more acidotic, salicylate enters CNS and by direct effect cause neuroglycopenia.

Hemodialysis is recommended in salicylate overdose patients with a level at or above 100 mg/dL (cut it to half if history suggest chronic ingestion). But if there is any sign of neurological manifestation, dialysis is indicated despite normal level.7 indications of Hemodialysis in Salicylate poisoning
Mental status change
Pulmonary edema
Cerebral edema
Associated or with renal failure
Level at or above 100 mg/dL(half if chronic ingestion)
If fluid overload prevents alkalinization
Patient continue to deteriorate clinically

References: Click to get abstract/article

1. Toxicity, Salicylate - emedicine.com
2.An evidence based flowchart to guide the management of acute salicylate (aspirin) overdose -Emerg Med J 2002; 19:206-209
3. Salicylic acid - intox.org

2008-07-30T21:59:00.000-07:00

Wednesday July 30, 2008
Regarding need of foley cather

Resident - Is there any reason patient can't have foley catheter?
Nurse - Is there any reason patient needs foley catheter?

2008-07-29T10:44:00.000-07:00

Tuesday July 29, 2008
Four generations of Quinolones

The classification of the fluoroquinolones on the basis of generations (imitating from cephalosporins) is not officially standardized, but it is now commonly use to classify them by their spectrum of action.

1st generation - Gram negative coverage but not pseudomonas (example: Nalidixic acid)

2nd generation - Gram negative coverage and some gram postive coverage including s.aureus but not strep pneumoniae. (example: Ciprofloxacin, Ofloxacin, Norfloxacin)

3rd generation - Gram negative coverage. More gram postive coverage including penicillin sensitive and resistant s. pneumoniae. (example: Levofloxacin, Sparfloxacin, Gatifloxacin (tequin), Moxifloxacin (avalox)). Avalox has been said to be the most effective in this generation.

4th generation - Same as 3rd generation but with anaerobic coverage (example: Trovafloxacin (Trovan) ).

Read comprehensive review on Quinolones (Source: Am Fam Physician 2002;65:455-64, authors: CATHERINE M. OLIPHANT, PHARM.D., University of Wyoming School of Pharmacy and GARY M. GREEN, M.D., Kaiser Permanente, California)

2008-07-28T10:43:00.000-07:00

Monday July 28, 2008

Case: 82 year old nursing home resident lady has been admitted to ICU with GI bleed, since she started taking aspirin on someone's advise. Otherwise, past medical history is significant only for hypertension for which she is taking lisinopril. While in ICU, she noticed to have "dirty urine" and has been started on Bactrim (sulfamethoxazole and trimethoprim). You get called as nurse noticed change in EKG rhythm. You ordered 12 leag EKG which is as follows. What is your diagnosis?

Answer: Bactrim Induced Hyperkalemia

Hyperkalemia due to Bactrim (sulfamethoxazole and trimethoprim) affects elderly patients frequently even with standard oral dosages, despite normal serum creatinine level. Concurrent angiotensin-converting enzyme inhibitor therapy increase the risk of hyperkalemia. Moreover, this patient may have pRBC transfusion which itself carries a load of potassium. In symptomatic patients, standard therapy for hyperkalemia is required otherwise withdrawal of drug is sufficient.

Reference: click to get abstract

Trimethoprim-induced hyperkalemia: An analysis of reported cases - Gerontology. 1999 Jul-Aug;45(4):209-12

2008-07-27T19:28:00.000-07:00

Sunday July 27, 2008
Ratio of Bumex (Bumetanide) to Lasix (Furesmide)

Q: What is the conversion equivalence of Bumex to Lasix?

A: 1 mg of Bumex is equal to 40 mg of Lasix.

2008-07-26T15:16:00.000-07:00

Saturday July 26, 2008
Regarding Vasopressin !

Q: How vasopressin acts differently in normal healthy people versus in septic patients?

A; A low-dose infusion of exogenous vasopressin induces a brisk pressor response in sepsis patients but shows little effect in normal subjects. In septic patients endogenous levels of the vasopressin are low and the pressor response to exogenous infusion would be noted.

Lin and coll. 1 drew plasma vasopressin level at baseline early in course of sepsis in emergency department and found that the plasma vasopressin level was significantly lower for those who finally developed septic shock (3.6 +/- 2.5 pg/mL) than severe sepsis (21.8 +/- 4.1 pg/mL).

Vasopressin antagonizes the vasodilatory mechanisms that are activated during sepsis. Although the hormone is an antidiuretic, it has been shown to increase urine output and improve creatinine clearance in shock patients. Vasopressin at low dose does not alter cerebral constriction or coronary flow, nor does it influence pulmonary arterial pressure.

As a rule of thumb, vasopressin is a good choice when sepsis is complicated by renal insufficiency and should be avioded in patients with limb, cardiac or bowel ischemia.

Related previous pearl: vasopressin/norepinephrine ratio

Reference: (click to get abstract)

1. Low plasma vasopressin/norepinephrine ratio predicts septic shock. Am J Emerg Med. 2005 Oct;23(6):718-24.

2008-07-25T07:24:00.000-07:00

Friday July 25, 2008
Classification of Lactic acidosis

Q: What is Type B1, Type B2 and Type B3 Lactic acidosis?

A; Basically, there are 2 types of Lactic acidosis A and B

Type A lactic acidosis: occurs in the setting of poor tissue perfusion or oxygenation. It is due to either overproduction or underutilization
Overproduction: Circulatory, pulmonary, or hemoglobin transfer disorders are commonly responsible.
Underutilization: Liver disease, gluconeogenesis inhibition, thiamine deficiency, and uncoupled oxidative phosphorylation

Type B lactic acidosis: is when there is no evidence of poor tissue perfusion. Type B is divided into 3 subtypes

Type B1 is assocciated with systemic disease such as renal and hepatic failure, diabetes, and malignancy.
Type B2 is caused by drugs and toxins including biguanides, alcohols, iron, isoniazid, and salicylates. Recently HIV drugs have been described too.

Type B3 is due to inborn errors of metabolism

2008-07-24T09:40:00.000-07:00

Thursday July 24, 2008

Q: 48 year old obese male with renal failure with baseline creatinine of 3.8 mg/dl but not yet on dialysis, presented with infection and needs IV fluid resuscitation. Patient ABG showed acidosis with PH of 7.24. Which of the following IV fluids will be relatively contraindicated in patient ?

A. Lactate Ringer
B. Hydroxyethyl starch (hextand)
C. THAM
D. Normal Saline with potassium mix
E. All of the above

Answer: All of the above

Objective of this question is to establish that choice of IV fluid is an immensely important factor in treatment of any patient and should be choose with caution.

Lactated Ringer's Solution contains 4 mEq/L of potassium and may not be a good choice in patients with renal failure.

There is substanial amount of literature available showing deleterious effect of Hydroxyethyl starch (like Hextand) on kidney particularly with already decreased function 1,2.

THAM is excreted by the kidneys and is contraindicated in renal failure.

Simply, normal saline is a good choice in hypovolumia but addition of potassium should be avoided in renal failure.

Related: Plasma expanders (Excellent presentation from Dr. Wayne Riback - pdf)

References:

1. Hydroxyethyl starch and renal dysfunction Transfusion Alternatives in Transfusion Medicine, Volume 9, Number 3, September 2007 , pp. 182-188(7)
2. Hydroxyethyl starch and change in renal function in patients undergoing coronary artery bypass graft surgery - Kidney International (2003) 64, 1046–1049

2008-07-23T08:27:00.000-07:00

Wednesday July 23, 2008

Q: 26 year old male presented to emergeny department with severe (10/10 in severity) abdominal pain. CT scan is perfectly normal. All lab works reported normal. Patient responded to pain killer and was admitted to hospital for observation and discharged next day. 2 days later patient presented with complain of witnessing bright red blood in stool. Again all workup, along with upper and lower GI scope is negative. Patient didn't ask for any pain medicine. Just before discharge, patient called nurse with statement - "I am having hematuria" and indeed urine appears reddish as well as UA showed RBCs. Ultrasound of KUB reported negative. Urology consult obtained for scope and was without any finding. While in recovery area after Cystoscopy, patient complaint of substernal chest pain and now admitted to your ICU. Initial cardiac enzymes are normal. Your diagnosis (Choose one)

A. Undiagnosed Pernicious anemia

B. Hemolytic anemia

C. Munchausen Syndrome

D. Subclinical Rhabdomyolysis

Answer: Munchausen Syndrome

Munchausen syndrome is a condition in which patient fake disease, illness, or psychological trauma in order to draw attention or sympathy to themselves. This "factitious disorders" are either self-induced or falsified. Other common name is hospital addiction syndrome.

Patients with Munchausen's Syndrome are usually knowledgeable about the practice of medicine and medical terminologies, and are able to manipulate physicians by inducing fever with warm coffee in mouth, making stool tarry with iron tablets or urine bloody with a drop of blood etc. These patients are not hypochondriac as they know that they are purposely faking the disease to gain attention or sympathy.

Suspicion should arise if symptoms appear dramatic but inconsistent with medical history or change once treatment has begun, or presence of symptoms only when the patient is alone or not being observed. Some patients have multiple surgical scars and are promptly willing to have medical tests, procedures or even surgeries.

Its a psychological disorder and need to be treated accordingly, though hard to treat.

2008-07-22T10:38:00.000-07:00

Tuesday July 22, 2008
Does BNP has any role in predicting mortality in patients with PE

Recent paper by Paul Marik helps to address that issue. In view of high risk of death in patients with pulmonary embolism, it is important to identify the factors associated with high mortality.

Objective: Evaluate the available evidence on (a) the accuracy of brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) for the diagnosis of right ventricular dysfunction and (b) their value as a prognostic factor of all-cause in-hospital or short-term mortality in patients with PE.

Results: The pooled diagnostic odds ratio for the diagnosis of right ventricular dysfunction in pulmonary embolism was 39.45 (95% CI; 15.54–100.12) and 24.73 (95% CI 2.02–302.37) for BNP and NT-proBNP, respectively. The pooled odds ratio for all-cause in-hospital or short-term mortality was 6 (95% CI 1.31–27.43; p: 0.021) and 16.12 (95% CI 3.1–83.68; p: 0.001) for BNP (cutoff: 100 pg/ml) and NT-proBNP (cutoff: 600 ng/L), respectively.

Conclusion: This meta-analysis study revealed that high BNP and NT-proBNP level is associated with right ventricular dysfunction in patient with acute PE and are significant predictors of all-cause in-hospital or short-term mortality in these patients.

Reference:

Cavallazzi R, Nair A, Vasu T, Marik P. Natriuretic peptides in acute pulmonary embolism: a systemic review. Intensive care Medicine. Online July 15 2008

2008-07-21T16:20:00.000-07:00

Monday July 21, 2008

Q: 6 elderly patients have been brought from nursing home in summer season due to heatstroke after AC (aircondioner) stop working in the facility. Nursing staff established IV (intravenous) lines quickly on arrival. You ordered lab work and 'cooling protocol' along with fluid resuscitation. But before IV fluid resuscitation starts which IV infusion is recommended?

Answer: Thiamine and Dextrose (D-50)

Hypoglycemia is very common in patients with heatstroke and actually may be a manifestation of underlying liver failure; therefore, infusion of dextrose 50% is recommnded in all patients with heatstroke.

Most of these patients are on malnutrition side and possibly thiamine deficient. Infusion of Dextrose may precipitate Wernicke's Encephalopathy* in these patients, therefore it is always a good idea to administer Thiamine before D-50 or addition of D-5 in IV fluid resuscitation.

* Disorder was described 25 years ago by Carl Wernicke as a triad of acute mental confusion, ataxia, opthalmoplegia

2008-07-20T08:55:00.001-07:00

Sunday July 20, 2008
DVT risk in order of type of trauma and surgery

Taken from site apcresistance.com

Reference:

Haas S. Impact of the European consensus statement on the clinical acceptance of low molecular weight heparin. Clin Appl Thromb Haemost 2, suppl 1, S35-S39 (1996)

2008-07-19T08:25:00.000-07:00

Saturday July 19, 2008

Q: What is Jacksonian seizure?

A: Jacksonian seizure is an unique type of simple partial seizures in which symptoms start in one part of the body, then spread to another - "epileptic march". Abnormal movements may occur in the hand or foot, then move up the limb as the electrical activity spreads in the brain. People are completely aware of what is occurring during the seizure.

Jacksonian seizures are extremely varied and may involve, for example, apparently purposeful movements such as turning the head, eye movements, smacking the lips, mouth movements, drooling, rhythmic muscle contractions in a part of the body, abnormal numbness, tingling, and a crawling sensation over the skin. These motor symptoms spread slowly from one part of the body to another.

(These seizures are named after an english neurologist, John Hughlings Jackson who described it in 1863)

2008-07-18T11:49:00.000-07:00

Friday July 18, 2008

Q: Which very commonly use drug in ICU may increase level of Fenoldopam by 30-70% when administered concurrently ?

Answer: Acetaminophen (Tylenol or Paracetamol)

Fenoldopam is a short-acting dopamine agonist (DA1) for management of severe HTN. It increases renal blood flow and sodium excretion. It is 10 times more potent than dopamine as renal vasodilator. Initial dose is 0.1-0.3 mcg/kg/min IV and should be increased cautiously to avoid reflex tachycardia in increments of 0.05-0.1 mcg/kg/min IV q15 min until target blood pressure achieved.

Fenoldpam is relatively contraindicated or should be used with caution in patients with glaucoma and angina. It may cause hypokalemia due to diuresis. Acetaminophen may increase levels by 30-70% when administered concurrently. Also beta-blockers increase risk of hypotension.

2008-07-17T11:51:00.000-07:00

Thursday July 17, 2008

Q: Which drug can make Liver as enhanced on imaging?

Answer: Amiodarone

An unenhanced computed tomography (CT) scan will show a greatly increased density, due to iodine accumulation.

Recommended reading:

Hepatotoxicity during rapid intravenous loading with amiodarone: Description of three cases and review of the literature - Critical Care Medicine:Volume 33(1)January 2005pp 128-134

2008-07-16T12:49:00.000-07:00

Wednesday July 16, 2008
Is enteral feeding is all we need in ICU???

It has been advocated for several years that one should start enteral feeding in intensive care unit as soon as possible. There are instances when patient is severely nutritionally depleted and enteral feeding may take a while, and is there any role for combination of enteral and parenteral feeding. Recent paper by Heidegger shed some light on it.

According to them, the evidence had shown that enteral nutrition can result in under-feeding and that nutritional goals are frequently reached only after one week. Contrary to former beliefs, recent meta-analyses of ICU studies showed that parenteral nutrition is not related to a surplus mortality and may even be associated with improved survival.

Conclusion: Early enteral nutrition is recommended in critically ill patients. Supplemental parenteral nutrition combined with enteral nutrition can be considered to cover the energy and protein targets when enteral nutrition alone fails to achieve the caloric goals. Whether this combined nutritional support provides any additional overall outcome benefit is yet to be determined. Further studies are suggested.

Reference: click to get abstract

Heidegger CP, Darmon B, Pichard CB. Enteral vs. parenteral nutrition for the critically ill patient: a combined support should be preferred. Current Opinion in Critical Care 2008; 14 (4): 408-414

2008-07-15T14:43:00.000-07:00

Tuesday July 15, 2008

Q: We prescribe Thiamine in alcohol withdrawal as it protects against delirium tremens (DTs)

A) True
B) False

Answer: False

Thiamine is recommended in alcoholic patients as it is useful in preventing Wernicke encephalopathy (triad of confusion, ataxia, ophthalmoplegia) and Korsakoff syndrome (consist of anterograde and retrograde amnesia, confabulation, lack of insight and apathy). But, thiamine has no effect on the symptoms of alcohol withdrawal or on the prevention of seizures or DTs.

Moreover, orally administered thiamine may have poor enteral absorption in alcoholic patients, so in the initial phase or in high-risk patients parenteral thiamine (100-250 mg once daily) should be prescribed.

2008-07-14T11:45:00.000-07:00

Monday July 14, 2008
ARDS is ARDS !!

No! its no different or easy even if ARDS occurs due to extrapulmonary causes. See this study recently published in Chest 1.

Background: ARDS can occur from the two pathogenetic pathways: a direct pulmonary injury (ARDSp); and an indirect injury (ARDSexp).The metaanalysis was aimed at evaluating whether there is any difference in mortality between the two groups.

Methods: MEDLINE, EMBASE, and CINAHL databases were searched for relevant studies published from 1987 to 2007, and included studies that have reported mortality in the two groups of ARDS.

Results: 34 studies were find. In all, the studies involved 4,311 patients with
2,330 patients in the ARDSp group and
1,981 patients in the ARDSexp group

Mortality was similar in the two groups.

The mortality was no different whether the studies were classified as prospective or retrospective; small or large; or observational or interventional

Conclusions: The results of this study suggest that there is no difference in mortality between these two groups. Further studies should focus on specific etiologies within the subgroups rather than focusing on the broader division of ARDSp and ARDSexp.

Reference: click to get abstract

Is the Mortality Higher in the Pulmonary vs the Extrapulmonary ARDS?: A Metaanalysis Agarwal et al. Chest. 2008; 133: 1463-1473

2008-07-13T22:39:00.000-07:00

Sunday July 13, 2008

Q; Which Venom poisoning is marked by following 10 clinical signs:

mydriasis,
nystagmus,
hypersalivation,
dysphagia,
restlessness (out of proportion)
bronchoconstriction,
bronchorrhea,
pharyngeal secretions,
diaphragmatic paralysis,
anaphylaxis

Hints: Its not a snake envenomation and signs occur within a few minutes after the sting

Answer: Scorpion Sting

See full review on Scorpion Sting (emedicine.com)

Will be available at our Toxicology / Drug overdose section

2008-07-12T00:09:00.000-07:00

Saturday July 12, 2008
Colonic Necrosis - unusual complication of Kayexalate-Sorbitol

We are using sodium polystyrene sulfonate (SPS or Kayexalate) since last 45 years with great confidence. It is a common practice to add sorbitol to dissolve Kayexalate mainly to avoid fecal impaction or possible bowel obstruction. Kayexalate binds intraluminal calcium and may cause constipation, fecal impaction or bowel obstruction.

One of the relatively unknown complication of Kayexalate-sorbitol combination is colonic necrosis, although has been reported in literature earlier. The exact reason for colonic necrosis is not clear but the diagnosis can be made by the pathologic examination of post-operative specimen or material from endoscopic biopsy and may require specialized expertise and special stains. Sorbitol part is taught to be responsible for complication.Intensivist need to be wary of possible complication of acute abdomen after administration of kayexalate-sorbitol in 1% of cases, particularly in first 24-36 hours.

2008-07-11T00:29:00.000-07:00

Friday July 11, 2008
Novoseven RT - New version of Novoseven (Recombinant Factor VII)

Novoseven RT is a new version or second generation of Novoseven (Recombinant Factor VII). RT stands for room temperature.

The new formulation allows the product to be stored at room temperature (up to 77 degrees Fahrenheit) for up to 2 years. NovoSeven RT contains sucrose and L-Methionine, which allow for storage at room temperature.

The original formula could be stored for three years at temperatures between 36 and 46 degrees Fahrenheit.

See Review and Recommendations for the Off Label Use of Recombinant Activated Human Coagulation Factor VII (Novoseven®) - VA MedSafe, Pharmacy Benefits Management Strategic Healthcare Group and the Medical Advisory Panel, February 2007 - pdf

Reference:

1. Novoseven RT - fda.gov

2008-07-10T00:28:00.000-07:00

Thursday July 10, 2008

Q: You have been called to ED (emergency deptt.) to evaluate a patient with organophosphate poisoning. You determine patient need intubation to protect and avoid aspiration pneumonia. Which drug you would like to avoid during intubation process?

A; succinylcholine

Organophosphate poisoining is marked by "SLUDGE" like syndrome (Salivation, Lacrimation, Urinary Incontinence, Diarrhea, GI hypermotility) and Succinylcholine also increases salivation. Moreover organophosphate may potentiate effects of succinylcholine. Succinylcholine is relatively contraindicated in Organophosphate poisoining.

Previous ICU pearl: Accidental succinylcholine in pseudocholinesterase deficiency

For people interested in "collection", here is one article on succinylcholine written in 1956 and printed in CANADIAN ANAESTHETISTS' SOCIETY JOURNAL (Can. Anaes. Soc J., vol. 3, no. 1, Jan., 1956) - pdf file

2008-07-09T10:21:00.000-07:00

Wednesday July 9, 2008
What if plasma exchange is not available as treatment of TTP

Q: You just diagnosed a patient with thrombotic thrombocytopenic purpura (TTP) but you were informed by the nursing supervisor that plasma exchange with fresh frozen plasma is not available in hospital due to technical reason and it will take time before patient can be transferred to a facility where the said services are available. What would be your alternate plan to bridge that time?

A; High-dose plasma infusion with rate of 25-30 mL/kg per day. When immediate plasma exchange with fresh frozen plasma is not available, simple plasma infusion can be performed until transfer to a higher facility is available. There is always a substanial risk of fluid overload with such high plasma infusion and you have to weigh risks and benefits of the clinical decision or to watch patient closely while plasma is infusing.

Reference: click to get abstract/article

High-dose plasma infusion versus plasma exchange as early treatment of thrombotic thrombocytopenic purpura/hemolytic-uremic syndrome - Medicine. 82(1):27-38, January 2003.

2008-07-08T06:46:00.000-07:00

Tuesday July 8, 2008
Corticosteroid and ARDS: Result of meta-analysis

Several articles have been written regarding role of steroids, its advantages or disadvantages in ARDS. Recently John Victor Peter and his group presented their findings in BMJ.

Method: Search of randomized controlled trials from years 1966 to april 2007.

Data extraction: Two investigators independently assessed trials for inclusion and extracted data into standardized forms. Differences were resolved by consensus.

Data synthesis: Nine randomized trials using variable dose and duration of steroids were identified. Preventive steroids (four studies) were associated with a trend to increase both the odds of patient developing ARDS (odds ratio 1.55), and the risk of mortality in those who subsequently developed ARDS (odds ratio 1.52).

Steroid administration after the onset of ARDS (five studies) was associated with a trend in reduction in mortality (odds ratio .62).
Steroid increase the number of ventilator free days compared to control (three studies, mean difference 4.05 days, 95% credible interval 0.22 to 8.71).
Use of steroids was not associated with increase in risk of infection.

Conclusion: Role of use of steroids in ARDS is not clearly established. Preventive use of steroids increase the incidence of ARDS in critically ill patients, whereas use of steroids after the onset of ARDS possibly reduces the mortality and increases the ventilator free days.

Reference: click to get abstract

Peter JV, John P, Graham PL, Moran JL, George IA, Bersten A. Corticosteroids in the prevention and treatment of acute respiratory distress syndrome (ARDS) in adults: meta-analysis. BMJ 2008; 336:1006-1009.

2008-07-07T09:30:00.000-07:00

Monday July 7, 2008
Is our ICU nurses sleepier then our floor nurses?

Recent paper published in Journal of Hospital Medicine from Surani and coll. helped to address this issue with their pilot study.

(Dr. S. Surani is co-editor of this website also)

METHODS: Post-night-shift nurses in the ICU and on general floors (medicine and surgery) were assessed using subjective (Epworth Sleepiness Scale [ESS]) and objective (Mean Sleep Latency Test [MSLT]) measures.

RESULTS:

ESS was abnormal (>8) in 7 of 10 ICU nurses compared with 2 of 10 floor nurses (P < .005), and mean ESS score was also higher (8.7 ± 3.9 vs. 5.6 ± 2.1, respectively; P = 0.042).
MSLT values for the first nap period were in the pathologic range in the ICU nurses compared with the floor nurses (4.65 ± 5.5 vs. 10.85 ± 7.4 minutes, respectively; P < .05).

CONCLUSIONS: Post-night-shift RNs working in the ICU have a pathologic degree of sleepiness.

Reference: click to get abstract

Surani S, Subramanyan S, Babbar H, Murphy J, Aguillar R. Sleepiness in critical care nurses: Results of a pilot study. Journal of Hospital Medicine 2008; 3(3):200-205