Friday July 16, 2010
A/C vs SIMV
Background: Few data are available regarding the benefits of one mode over another for ventilatory support. We set out to compare clinical outcomes of patients receiving synchronized intermittent mandatory ventilation with pressure support (SIMV-PS) compared with assist-control (A/C) ventilation as their primary mode of ventilatory support.
Methods: This was a secondary analysis of an observational study conducted in 349 ICUs from 23 countries. A propensity score stratified analysis was used to compare 350 patients ventilated with SIMV-PS with 1,228 patients ventilated with A/C ventilation. The primary outcome was in-hospital mortality.
Results: In a logistic regression model, patients were more likely to receive SIMV-PS if they were from North America, had lower severity of illness, or were ventilated postoperatively or for trauma. SIMV-PS was less likely to be selected if patients were ventilated because of asthma or coma, or if they developed complications such as sepsis or cardiovascular failure during mechanical ventilation.
In the stratified analysis according to propensity score, we did not find significant differences in the in-hospital mortality. After adjustment for propensity score, overall effect of SIMV-PS on in-hospital mortality was not significant (P = .78).
Conclusions: In our cohort of ventilated patients, ventilation with SIMV-PS compared with A/C did not offer any advantage in terms of clinical outcomes, despite treatment-allocation bias that would have favored SIMV-PS.
Outcomes of Patients Ventilated With Synchronized Intermittent Mandatory Ventilation With Pressure Support - A Comparative Propensity Score Study CHEST June 2010 vol. 137 no. 6 1265-1277
Friday, July 16, 2010
Wednesday, July 14, 2010
Wednesday July 14, 2010
"MAZE" Procedure - simply explained!
The MAZE procedure consists of creating a number of incisions in the atrium that disrupt the re-entrant circuits. Once the incisions are made, they are sewn together again. The atrium can then hold blood on its way to the ventricle and can squeeze or contract to push the blood in to the ventricle, but the electrical impulse cannot cross the incisions. The result is what looks like a children's maze in which there is only one path that the electrical impulse can take from the SA node to the AV node. The atrium can no longer fibrillate, and sinus rhythm (the normal rhythm of the heart) is restored.
"MAZE" Procedure - simply explained!
The MAZE procedure consists of creating a number of incisions in the atrium that disrupt the re-entrant circuits. Once the incisions are made, they are sewn together again. The atrium can then hold blood on its way to the ventricle and can squeeze or contract to push the blood in to the ventricle, but the electrical impulse cannot cross the incisions. The result is what looks like a children's maze in which there is only one path that the electrical impulse can take from the SA node to the AV node. The atrium can no longer fibrillate, and sinus rhythm (the normal rhythm of the heart) is restored.
Tuesday, July 13, 2010
Tuesday July 13, 2010
Q: Why Vitamin K is called Vitamin "K"?
Answer:
Its called Vitamin K from its german origin"Koagulations-Vitamin".
Story of Vitamin K: In 1929, Danish scientist Henrik Dam investigated the role of cholesterol by feeding chickens a cholesterol-depleted diet. After several weeks, the animals developed hemorrhages and started bleeding. These defects could not be restored by adding purified cholesterol to the diet. It appeared that—together with the cholesterol—a second compound had been extracted from the food, and this compound was called the coagulation vitamin. The new vitamin received the letter K because the initial discoveries were reported in a German journal, in which it was designated as Koagulationsvitamin.
Q: Why Vitamin K is called Vitamin "K"?
Answer:
Its called Vitamin K from its german origin"Koagulations-Vitamin".
Story of Vitamin K: In 1929, Danish scientist Henrik Dam investigated the role of cholesterol by feeding chickens a cholesterol-depleted diet. After several weeks, the animals developed hemorrhages and started bleeding. These defects could not be restored by adding purified cholesterol to the diet. It appeared that—together with the cholesterol—a second compound had been extracted from the food, and this compound was called the coagulation vitamin. The new vitamin received the letter K because the initial discoveries were reported in a German journal, in which it was designated as Koagulationsvitamin.
Monday, July 12, 2010
Monday July 12, 2010
Q: What is urinothorax?
Answer: Presence of urine in pleural cavity is called Urinothorax. Urinothorax can occur from urinary tract injury or obstruction - and leakage of urine from the peritoneal and retroperitoneal space into the pleural space.
Urinothorax usually causes a rapidly accumulating pleural effusion. Most cases of urinothorax are due to obstruction, secondary to tumor/metastasis, or trauma of the ureter. In other cases, retroperitoneal fibrosis, shock wave lithotripsy, and removal/blockage of nephrostomy tubes may result in the formation of an urioma. Nephropleural fistula may form, allowing urine to enter the pleural cavity. Accidental placement of nephrostomy tubes too cephalically in the thorax may cause urinthorax too.
Diagnosis: Urinothorax should be suspected if the sample is straw colored or has a urine-like odor. Measurement of pleural creatinine to serum creatinine has been found to be the most reliable laboratory value and should be the definitive evaluation of urinothorax. Pleural fluid/serum creatinine ratio higher than 1 is diagnostic in association with other features. Moreover urinothorax may be both transudative and acidic (lower than 7.30).
Q: What is urinothorax?
Answer: Presence of urine in pleural cavity is called Urinothorax. Urinothorax can occur from urinary tract injury or obstruction - and leakage of urine from the peritoneal and retroperitoneal space into the pleural space.
Urinothorax usually causes a rapidly accumulating pleural effusion. Most cases of urinothorax are due to obstruction, secondary to tumor/metastasis, or trauma of the ureter. In other cases, retroperitoneal fibrosis, shock wave lithotripsy, and removal/blockage of nephrostomy tubes may result in the formation of an urioma. Nephropleural fistula may form, allowing urine to enter the pleural cavity. Accidental placement of nephrostomy tubes too cephalically in the thorax may cause urinthorax too.
Diagnosis: Urinothorax should be suspected if the sample is straw colored or has a urine-like odor. Measurement of pleural creatinine to serum creatinine has been found to be the most reliable laboratory value and should be the definitive evaluation of urinothorax. Pleural fluid/serum creatinine ratio higher than 1 is diagnostic in association with other features. Moreover urinothorax may be both transudative and acidic (lower than 7.30).
Saturday, July 10, 2010
Saturday July 10, 2010
Cardio-pulmonary arrest in cocaine overdose
Q: Why vasopressin is preferable over epinephrine in cardio-pulmonary arrest due to cocaine overdose?
Answer: Epinephrine like cocaine has alpha-adrenergic effects. Because of this similarity in the cardiovascular effects, the administration of epinephrine to a patient who arrests in a hyperadrenergic state has been like "pouring gasoline over fire."
Moreover, cocaine prevents the reuptake of exogenously administered epinephrine. Therefore, if epinephrine is used, AHA Guidelines recommends that high-dose epinephrine should be avoided and that the interval for its administration be increased (q 5-10min).
Vsopressin offer considerable advantages over epinephrine in cardiac arrest secondary to cocaine toxicity. The hyperadrenergic state caused by cocaine increases myocardial oxygen demand and vasopressin increases coronary blood flow, and thereby myocardial oxygen availablity.
Also, cocaine toxicity causes acidosis and epinephrine loses much of its effectiveness in an acidotic enviroment, whereas vasopressin demonstrates good efficacy even with severe acidosis.
Cardio-pulmonary arrest in cocaine overdose
Q: Why vasopressin is preferable over epinephrine in cardio-pulmonary arrest due to cocaine overdose?
Answer: Epinephrine like cocaine has alpha-adrenergic effects. Because of this similarity in the cardiovascular effects, the administration of epinephrine to a patient who arrests in a hyperadrenergic state has been like "pouring gasoline over fire."
Moreover, cocaine prevents the reuptake of exogenously administered epinephrine. Therefore, if epinephrine is used, AHA Guidelines recommends that high-dose epinephrine should be avoided and that the interval for its administration be increased (q 5-10min).
Vsopressin offer considerable advantages over epinephrine in cardiac arrest secondary to cocaine toxicity. The hyperadrenergic state caused by cocaine increases myocardial oxygen demand and vasopressin increases coronary blood flow, and thereby myocardial oxygen availablity.
Also, cocaine toxicity causes acidosis and epinephrine loses much of its effectiveness in an acidotic enviroment, whereas vasopressin demonstrates good efficacy even with severe acidosis.
Friday, July 9, 2010
Friday July 9, 2010
Q; Patient with C. Diff. Colitis is having no improvement with PO Flagyl. You ordered PO Vancomycin. Pharmacy informed you that PO Vancomycin is not available. What would be your trick of trade here?
A; Actually, IV Vancomycin can be given via oral route. It works just as well, and a lot cheaper. The ordered dose may be diluted in water and given to the patient to drink. Common flavoring syrups may be added to the solution to improve taste.
Q; Patient with C. Diff. Colitis is having no improvement with PO Flagyl. You ordered PO Vancomycin. Pharmacy informed you that PO Vancomycin is not available. What would be your trick of trade here?
A; Actually, IV Vancomycin can be given via oral route. It works just as well, and a lot cheaper. The ordered dose may be diluted in water and given to the patient to drink. Common flavoring syrups may be added to the solution to improve taste.
Thursday, July 8, 2010
Thursday July 8, 2010
SfVO2? - Nah!
Background: Central venous oxygen saturation (Scvo2) has been used as a surrogate marker for mixed venous oxygen saturation (Svo2). Femoral venous oxygen saturation (Sfvo2) is sometimes used as a substitute for Scvo2. The purpose of this study is to test the hypothesis that these values can be used interchangeably in a population of patients who are critically ill.
Methods: We conducted a survey to assess the frequency of femoral line insertion during the initial treatment of patients who are critically ill. Patients with femoral and nonfemoral central venous catheters (CVCs) were included in this prospective study. Two sets of paired blood samples were drawn simultaneously from the femoral and nonfemoral CVCs. Blood samples were analyzed for oxygen saturation and lactate.
Results: Thirty-nine patients were enrolled.
- The mean Scvo2 and Sfvo2 were 73.1% ± 11.6% and 69.1% ± 12.9%, respectively (P = .002), with a mean bias of 4.0% ± 11.2% (95% limits of agreement: −18.4% to 26.4%).
- The mean serum lactate from the nonfemoral and femoral CVCs was 2.84 ± 4.0 and 2.72 ± 3.2, respectively (P = .15).
Conclusions: This study revealed a significant difference between paired samples of Scvo2 and Sfvo2. More than 50% of Scvo2 and Sfvo2 values diverged by more than 5%. Sfvo2 is not always a reliable substitute for Scvo2 and should not routinely be used in protocols to help guide resuscitation.
Femoral-Based Central Venous Oxygen Saturation Is Not a Reliable Substitute for Subclavian/Internal Jugular-Based Central Venous Oxygen Saturation in Patients Who Are Critically Ill - Chest July 2010 138:76-83; also published ahead of print April 23, 2010.
Wednesday, July 7, 2010
Wednesday July 7, 2010
Q: Patient reports allergy to albumin as well as charted as Jehovah's Witnesses but require large volume Paracentesis. What's your other option?
A: Terlipressin (eg, 1 mg every 4 hours for 48 hours) can be use as an alternative to albumin for the prevention of circulatory colapse after large-volume paracentesis. Terlipressin is said to be as effective as albumin for this purpose.
Q: Patient reports allergy to albumin as well as charted as Jehovah's Witnesses but require large volume Paracentesis. What's your other option?
A: Terlipressin (eg, 1 mg every 4 hours for 48 hours) can be use as an alternative to albumin for the prevention of circulatory colapse after large-volume paracentesis. Terlipressin is said to be as effective as albumin for this purpose.
Tuesday, July 6, 2010
Tuesday July 6, 2010
Swallowing Dysfunction in "Trach" Patients
Background: The aim of this study was to determine the incidence of swallowing dysfunction in nonneurologic critically ill patients who require percutaneous dilatational tracheostomy (PDT) for prolonged mechanical ventilation (MV) and to compare the duration of the cannulation period and length of stay in the critical care unit (CCU) in patients with and without swallowing dysfunction.
Methods: A total of 40 consecutive patients without neurologic disorders who require PDT for prolonged MV were included. Previous to the tracheostomy decannulation process, an otolaryngologist performed a fiberoptic endoscopic evaluation of swallowing (FEES).
Results: Mean age was 62 ± 15 years. Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores were 21 ± 2 and 9 ± 1, respectively. Time of MV previous to PDT was 20 ± 11 days, total MV duration was 38 ± 16 days, and CCU stay was 63 ± 27 days.
- The incidence of swallowing dysfunction in this group of patients was 38% (15/40).
- No difference was found in the age or time period of MV previous to PDT between groups.
- The time period between FEES to tracheostomy decannulation process was 19 ± 11 days in patients with swallowing dysfunction vs 2 ± 4 days in those patients without dysfunction
- Patients who developed swallowing dysfunction stayed longer in the CCU (69 ± 23 vs 47 ± 19 days)
Conclusions: Nearly 40% of nonneurologic critically ill patients requiring PDT for prolonged MV presented swallowing dysfunction and experienced a significant delay in their tracheostomy decannulation process.
Swallowing Dysfunction in Nonneurologic Critically Ill Patients Who Require Percutaneous Dilatational Tracheostomy - Chest June 2010 137:1278-1282; published ahead of print March 18, 2010
Monday, July 5, 2010
Sunday, July 4, 2010
Saturday, July 3, 2010
Saturday July 3, 2010
Stages of Decub ulcer
Stage I
This stage is characterized by a surface reddening of the skin. The skin is unbroken and the wound is superficial. This decubitus ulcer quickly fades when pressure is gone. Treatment consists of turning or alleviating pressure. Increased nutrition is part of prevention.
Stage II
This stage is characterized by a blister either broken or unbroken. A partial layer of the skin is now injured. Involvement is no longer superficial. The goal of care is to cover, protect, and clean the area.
Stage III
The wound extends through all of the layers of the skin. It is a primary site for a serious infection to occur. The goals and treatments of alleviating pressure and covering and protecting the wound still apply as well as an increased emphasis on nutrition and hydration.
Stage IV
A Stage IV wound extends through the skin and involves underlying muscle, tendons and bone. The diameter of the wound is not as important as the depth. This is very serious and can produce a life threatening infection. All of the goals of protecting, cleaning and alleviation of pressure on the area still apply. Nutrition and hydration is now critical. Without adequate nutrition, this wound will not heal. Anyone with a Stage IV wound requires medical care by someone skilled in wound care. Surgical removal of the necrotic or decayed tissue is often used on wounds of larger diameter.
Stages of Decub ulcer
Stage I
This stage is characterized by a surface reddening of the skin. The skin is unbroken and the wound is superficial. This decubitus ulcer quickly fades when pressure is gone. Treatment consists of turning or alleviating pressure. Increased nutrition is part of prevention.
Stage II
This stage is characterized by a blister either broken or unbroken. A partial layer of the skin is now injured. Involvement is no longer superficial. The goal of care is to cover, protect, and clean the area.
Stage III
The wound extends through all of the layers of the skin. It is a primary site for a serious infection to occur. The goals and treatments of alleviating pressure and covering and protecting the wound still apply as well as an increased emphasis on nutrition and hydration.
Stage IV
A Stage IV wound extends through the skin and involves underlying muscle, tendons and bone. The diameter of the wound is not as important as the depth. This is very serious and can produce a life threatening infection. All of the goals of protecting, cleaning and alleviation of pressure on the area still apply. Nutrition and hydration is now critical. Without adequate nutrition, this wound will not heal. Anyone with a Stage IV wound requires medical care by someone skilled in wound care. Surgical removal of the necrotic or decayed tissue is often used on wounds of larger diameter.
Friday, July 2, 2010
Friday July 2, 2010
Q: You confirmed propofol infusion syndrome in a patient on prolong high concentration infusion. Once you stop propofol how long does it take to recover from propofol associated lactic acidosis?
Answer: About 6 hours
Propofol infusion syndrome (PRIS) has been observed in patients receiving propofol at high dosages and for prolonged periods though reported with lower doses as well as short infusion time. It is said to be synergestic when given concomitantly with catecholamines or steroids in the setting of acute neurologic or inflammatory diseases.
Propofol infusion syndrome is said to occur in patients with genetic mitochondrial abnormalities.
MCQ on PRIS here (posted here earlier)
Q: You confirmed propofol infusion syndrome in a patient on prolong high concentration infusion. Once you stop propofol how long does it take to recover from propofol associated lactic acidosis?
Answer: About 6 hours
Propofol infusion syndrome (PRIS) has been observed in patients receiving propofol at high dosages and for prolonged periods though reported with lower doses as well as short infusion time. It is said to be synergestic when given concomitantly with catecholamines or steroids in the setting of acute neurologic or inflammatory diseases.
Propofol infusion syndrome is said to occur in patients with genetic mitochondrial abnormalities.
MCQ on PRIS here (posted here earlier)
Thursday, July 1, 2010
Thursday July 1, 2010
Q: 34 year old male with previous history of lung transplant is admitted to ICU with sepsis. Patient is recovering well but continue to have persistent ileus. Junior resident wrote for erythromycin to increase GI motility. What need to be watch in this patient?
Answer: Tacrolimus level
Tacrolimus has clinically major drug interactions with erythromycin, dilantin and rifampin. Erythromycin may increase Tacrolimus to toxic level. It is recommended that concurrent administration of erythromycin and tacrolimus be avoided. However, if concomitant therapy is necessary, tacrolimus concentrations should be monitored.
Other significant interactions Tacrolimus may have is with amphotericin, barbiturates, calcium channel blockers, itraconazole, ketoconazole, fluconazole, cyclosporine, and cimetidine.
Q: 34 year old male with previous history of lung transplant is admitted to ICU with sepsis. Patient is recovering well but continue to have persistent ileus. Junior resident wrote for erythromycin to increase GI motility. What need to be watch in this patient?
Answer: Tacrolimus level
Tacrolimus has clinically major drug interactions with erythromycin, dilantin and rifampin. Erythromycin may increase Tacrolimus to toxic level. It is recommended that concurrent administration of erythromycin and tacrolimus be avoided. However, if concomitant therapy is necessary, tacrolimus concentrations should be monitored.
Other significant interactions Tacrolimus may have is with amphotericin, barbiturates, calcium channel blockers, itraconazole, ketoconazole, fluconazole, cyclosporine, and cimetidine.
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