Wednesday March 12, 2008
Restless Legs syndrome

Restless legs syndrome is a common condition in non-intubated patients which may get aggravated by ICU enviroment. Major factors associated with Restless Leg Syndrome in ICU are

• Iron-deficiency anemia
• Peripheral neuropathy
• Withdrawal from vasodilator drugs and sedatives
• Cigarette smoking, alcohol and caffeine withdrawal
• Various drugs including phenytoin, antidepressant drugs, H2 blockers, lithium, beta-blockers and antipsychotics
• Hypomagnesemia
• Renal insufficiency (uremia)

Various pharmacological agents have been described and used with success including benzodiazepines, carbamazepine and clonidine. In ICU situation, one useful drug in this regard is Ropinirole which is a Dopamine agonist. One of the effect of Ropinirole is heavy sleepiness, which can be use as a bonus benefit in ICU. Dose can be initiated from .25 mg PO QHS upto 4 mg PO QHS.



References: (click to get abstract)

1. Restless Legs Syndrome: Detection and Management in Primary Care - NATIONAL HEART, LUNG, AND BLOOD INSTITUTE WORKING GROUP ON RESTLESS LEGS SYNDROME - Vol. 62/No. 1 (July 1, 2000) - American Family Physician.

2. Ropinirole is effective in the treatment of restless legs syndrome. TREAT RLS 2: a 12-week, double-blind, randomized, parallel-group, placebo-controlled study - Mov Disord. 2004 Dec;19(12):1414-23.

Tuesday March 11, 2008
Efficacy of risperidone for prevention of postoperative delirium in cardiac surgery

Interesting study particularly for folks working in cardio-thoracic ICUs. This randomised, double-blinded, placebo-controlled study was primarily aimed to evaluate the potential of risperidone to prevent postoperative delirium following cardiac surgery with cardiopulmonary bypass. The secondary objective was to explore clinical factors associated with postoperative delirium.

Number: 126 adult patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomly assigned to receive either 1 mg of risperidone or placebo sublingually when they regained consciousness.

The confusion assessment method for intensive care unit was used to assess postoperative delirium.


Results:

• The incidence of postoperative delirium in the risperidone group was lower than the placebo group (11.1% vs. 31.7% ).
• Other postoperative outcomes were not statistically different between the groups.
• Many factors were associated with postoperative delirium. However multiple logistic regression analysis showed a lapse of 70 minutes from the time of opening eyes to following commands and postoperative respiratory failure were independent risk factors.

Conclusion: A single dose of risperidone administered soon after cardiac surgery with cardiopulmonary bypass reduces the incidence of postoperative delirium. Multiple factors tended to be associated with postoperative delirium, but only the time from opening eyes to following commands and postoperative respiratory failure were independent risk factors in this study.



Reference:

Efficacy of risperidone for prevention of postoperative delirium in cardiac surgery - Anest. and Intensive care, Volume 35, No. 5, 2007, 714-719

Monday March 10, 2008
Percutaneous tracheostomy with Blue Rhino (2nd video is Bronchoscopic view)

Sunday March 9, 2008
Heparin Induced HyperKalemia

Hyperkalemia from Heparin is a well know phenomenon and has been detected particularly on geriatric, renal insufficient and diabetic patients. Hyperkalemia can be anywhere from .3 to 1.7 mEq/Litre. It usually occurs around on day 3 with SQ heparin (as for DVT prophylaxis) but can occur early with IV heparin 1,2,3,4.

Hyperkalemia has been reported with low- molecular weight heparins too but risk is low 5, 6, 7. Mechanism of action: Heparin induce hypoaldosteronism and can subsequently lead to hyperkalemia 6.Treatment: Best thing is to discontinue the culprit but if heparin is absolutely required, fludrocortisone (.1 mg/day) has been reported to be effective in heparin-induced hyperkalemia 8.


References: Click to get abstracts/articles

1. Case report - Heparin-induced hyperkalemia after cardiac surgery - Ann Thorac Surg 2002;74:1698-1700
2. Heparin-induced hyperkalemia -The Annals of Pharmacotherapy: Vol. 24, No. 3, pp. 244-246.
3. Heparin Induced HyperKalemia - Endocrine Abstracts (2002) 4 P26
4. Heparin-Induced Hyperkalemia Confirmed by Drug Rechallenge. American Journal of Physical Medicine & Rehabilitation. 79(1):93-96, January/February 2000.
5. Early onset of hyperkalemia in patients treated with low molecular weight heparin: a prospective study - Pharmacoepidemiol Drug Saf.2004 May;13(5):299-302.
6. Effect of Low-Molecular-Weight Heparin on Potassium Homeostasis - Pathophysiology of Haemostasis and Thrombosis 2002;32:107-110
7. Low Molecular Weight Heparins Can Lead To Hyperkalaemia The Internet Journal of Geriatrics and Gerontology . 2005. Volume 2 Number 2.
8. Fludrocortisone for the treatment of heparin-induced hyperkalemia - The Annals of Pharmacotherapy: Vol. 34, No. 5, pp. 606-610

Saturday March 8, 2008
Response to Warfarin during Initial Anticoagulation is genes dependent !

We all are aware of situations where warfarin (coumadin) takes forever to get upto therapeutic level despite escalating dose. One study of 297 patients who were starting warfarin therapy, is published this week in The New England Journal of Medicine.

2 genotypes were assessed CYP2C9 genotypes VKORC1 haplotypes

Study found that initial variability in the INR response to warfarin was more strongly associated with genetic variability in the pharmacologic target of warfarin, VKORC1, than with CYP2C9.



Reference: click to get abstract/article

1. Genetic Determinants of Response to Warfarin during Initial Anticoagulation - Number 10, Volume 358:999-1008, March 6, 2008, The New England Journal of Medicine

Friday March 7, 2008
Ice test - Poor man's test for Myasthenia Gravis

Most of the Myasthenia patients along with other symptoms of weakness usually exhibits ptosis. While at bedside place an ice cube over eye lids for 2 minutes. Cooling improves neuromuscular transmission. Resolution of ptosis with cooling is a positive test for Myasthenia Gravis and reported upto 80% reliable to diagnose ocular myasthenia.

Related: Click here to read good review article on Myasthenia Gravis ( Dr. Milind J. Kothari The Journal of the American Osteopathic Association.Vol 104 • No 9 • Sept. 2004 • 377-384)

Thursday March 6, 2008

Q; While you prescribe 15 mmol of intravenous (IV) potassium phosphate to patient, what amount of potassium is received by patient ?

A; About 20 meq

To be precise, 1 mmol of intravenous phophate delivers 1.46 meq of potassium in "K-phos rider".

To make it in round figure, 7.5 mmol of phosphate is equal to about 10 meq of potassium.

By mouth repletion of phosphate is preferable but if used, intravenous phosphate should be given very slowly. Usual recommended infusion rate is 5 mmol/hour. Rapid phosphate infusion may lead to precipitous fall in serum calcium, hypotension, and acute renal failure. Also, it may lead to hypomagnesemia, metastatic soft tissue calcifications, hypernatremia and volume loss from osmotic diuresis.



Reference: click to get article / abstract

Intravenous phosphate repletion regimen for critically ill patients with moderate hypophosphatemia - Critical Care Medicine. 23(7):1204-1210, July 1995.

Wednesday March 5, 2008
Bedside precaution

If patient is recieving Lactate Ringer's solution, than lactate level should not be drawn from same infusion catheter to avoid erroneously high level of lactate. It should be drawn from catheter at any other site of body or peripherally.

Though, once inside circulation lactate ringer does not have any clinically significant effect on serum lactate level.



Reference: click to get abstract / article

1. Effects of crystalloid solutions on circulating lactate concentrations: Part 1. Implications for the proper handling of blood specimens obtained from critically ill patients - Critical Care Medicine. 25(11):1840-1846, November 1997

Tuesday March 4, 2008

Q; One bag unit of cryoprecipitate is expected to raise fibrinogen by what level?

A; A bag of transfused cryoprecipitate is expected to raise the fibrinogen level by a minimum of 30 mg/dL with a half life of 3 to 6 days. Fibrinogen levels of more than 100 mg/dL generally are considered adequate for hemostasis.

Monday March 3, 2008

Q; During lumbar puncture (LP), what is the normal rate of cerebrospinal fluid (CSF) escape via needle into collecting tube ?

A; 1 drop per second

While performing LP, CSF should drop into tube with approximate rate of one drop/sec. A continuous stream of CSF indicates raised intrameningeal pressure.

Sunday March 2, 2008

Q; 37 year old male admitted to ICU with inability to walk and severe pain in lower extremities. On examination in ER, he was found to have cold feet. No pulses were palpable even in femoral area. Previous record available in hospital computer shows outpatient visits to urology clinic for 'impotency' ?


Answer: Leriche's syndrome

Leriche's syndrome is a triad of

• absent or diminished femoral pulses,
• intermittent claudication (pain with walking) and
• penile impotence.

It usually affects males caused by atheromatous involvement or occlusion of the abdominal aorta by a thrombus just above the site of its bifurcation. Onset usually between 30 and 40 years of age. Treatment is surgical.

Leriche Syndrome: Coronal reconstruction from a contrast-enhanced abdominal CT scan shows complete occlusion of the infrarenal aorta (red arrow) by thrombus that extends into both common iliac arteries (yellow arrows). The white arrow points to calcification in the wall of the vessel.

Reference: click to get abstract / article

1. Leriche syndrome. Surgical procedures and early and late results - Angiology. 1997 Jul;48(7):637-42

Saturday March 1, 2008
Palliative care - Death Rattle

Patients at end of life process, lose their ability to clear oral secretions. As air moves over the secretions, which have pooled in the respiratory tract, the resulting turbulence produces noisy ventilation, call Death rattle.

One easy bedside tip is to use 1% Atropine ophthalmic drops sublingually. Time of onset for action is about 30 minutes. It can be given every 2 hours PRN.

Other treatments are scopolamine patch placed behind the ear once every three days, Benadryl 25-100mg every 4 to 6 hours PRN or Robinul (glycopyrrolate) - 400 mcg SC every 8 hours PRN.