Saturday December 26, 2009
About Tolvaptan (Samsca)

Tolvaptan (Samsca) is the first oral dosage form in a class known as “selective vasopressin antagonists.” These drugs, also referred to as “vaptans,” cause renal elimination of water without increasing urinary excretion of sodium or potassium. An injectable vaptan, conivaptan (Vaprisol), has been available in the U.S. since 2006. Both conivaptan and tolvaptan are indicated for the treatment of hyponatremia. In addition, tolvaptan has been studied for treating heart failure.

Once-daily Samsca has been shown to significantly raise serum sodium concentrations in as early as 8 hours, and the change was maintained for 30 days. Exposure and response to Samsca are similar in patients with a creatinine clearance of 10-79 mL/min and in patients without renal impairment; thus no dosage adjustment is necessary.

The unique mechanism of action of Samsca selectively blocks the binding of vasopressin to the V2-receptors in the collecting duct of the kidney. If the V2-receptors are left unblocked, the binding of vasopressin with these receptors can cause water retention resulting in hyponatremia. By inhibiting the effects of vasopressin at the V2-receptor, Samsca increases the excretion of free water, while the excretion of sodium and other electrolytes is not directly affected (aquaresis).

Friday December 25, 2009


Merry Christmas

Thursday December 24, 2009


Q: What is the rule of thumb to select size of IABP (Intra Aortic Ballon Pump)?

Answer: The size of the balloon is dependent on the patients height to prevent occlusion of sub-clavian or renal arteries.

Less than 160 cm use 34 cc
Between 160 – 182 cm use 40 cc
More than 182 cm use 50 cc

Wednesday December 23, 2009
Esophageal Perforation Associated With Noninvasive Ventilation - An interesting Case Report

"A 56-year-old man was admitted to our ICU after extensive nephrectomy with partial inferior vena cava resection for renal adenocarcinoma. He had a history of type 2 diabetes mellitus, and the cancer had been diagnosed on evaluation of recent-onset severe arterial hypertension.

The patient was extubated on the day of surgery. No respiratory, circulatory, or infectious complications occurred, but renal failure developed gradually, the suspected cause being intraoperative hypotension. No nausea or vomiting was noted. NIPPV was started via a facemask on day 4 because this morbidly obese patient (122 kg) could not be weaned from nasal oxygen and had persistent moderate hypoxemia with persistent basal atelectasis on the chest radiograph. NIPPV was initiated with a fraction of inspired oxygen of 0.5, a positive end-expiratory pressure of 5 cm H2O, and a pressure-support level of 15 cm H2O. When NIPPV was stopped after 1 h, the hypoxemia worsened, and marked tachypnea with agitation developed. NIPPV was immediately restarted and the pulse oximetric saturation dropped to 97%. After an additional 2 h of NIPPV, hypotension and loss of consciousness occurred, requiring orotracheal intubation, mechanical ventilation, and vasoactive drug therapy. The postintubation chest radiograph disclosed left-sided hydropneumothorax, which was confirmed by CT. A chest tube was inserted, and 1,000 mL of gastric-like fluid was recovered. A left thoracotomy was performed, and a 3-cm linear tear was seen in the lower esophagus. The tear was sutured, drains were placed in the pleural cavity and mediastinum, and a discharge gastrostomy was performed with a jejunostomy for enteral nutrition.

After a transient improvement in the hemodynamic status, multiple organ failure developed. There was no definitive evidence of infection. The patient died 12 days after the thoracotomy".


Source:

Esophageal Perforation Associated With Noninvasive Ventilation - A Case Report, CHEST November 2002 vol. 122 no. 5, 1857-1858

Tuesday December 22, 2009


Q: Define Hemothorax?

Answer: Even a very small quantity of blood can make pleural fluid apppears bloody but a hemothorax is the presence of blood in the pleural cavity such that the ratio of pleural fluid hematocrit to blood hematocrit is more than 0.5.

Monday December 21, 2009
2 CD VIP

In response to our yesterday pearl "WEANS NOW" we received following pearl from

MABULMAGD , MD, EDIC
Lecturer of critical care medicine, Cairo university
Consultant intensivist, Dar Alfouad Hospital


I found this mnemonics helpful for intensivist during daily clinical rounds (2 CDF VIP)

2C,2D,2F
2V,2I,2P

2C..consciousness-connections

2D…hemoDynamics-diuresis

2F..fluids-feeding

2V..ventilation-vasopressors

2I..investigations-drug Interactions

2P…dvt prophylaxis-ulcer prophylaxis

Sunday December 20, 2009
Famous "WEANS NOW" of Ventilator Weaning

W: weaning parameter - measure
E: endotracheal tube (too small ?, obstruction ? etc)
A: alkalosis (may cause apnea) or anxiety
N: nutrition
S: secretion

N: neuromuscular disease
O: obstruction, bronchospasm
W: wait !!!