Sunday December 7, 2008
Q: 36 year old male with history of pulmonary hypertension is admitted to ICU with shortness of breath. List of medication includes Revatio. What is Revatio?
A: Revatio is another trade name for Sildenafil (Viagra). The white, round pills looks different from Viagra's blue diamond shape. This is to avoid embarassment for patients with pulmonary hypertension, if they present to pharmacy with Sildenafil prescription. Moreover, it helps to avoid confusion in medical history part.
Sunday, December 7, 2008
Saturday, December 6, 2008
Saturday December 6, 2008
Dosing of Esmolol
Q: How much time does it take for esmolol to reach steady-state blood levels, if you don't use loading dose for esmolol infusion?
A: Using an appropriate loading dose, steady-state blood levels of Esmolol for dosages from 50-300 mcg/kg/min (0.05-0.3 mg/kg/min) are obtained within 5 minutes, otherwise it takes 30 minutes to reach steady-state without the loading dose. Steady-state blood levels of Esmolol increase linearly over this dosage range and elimination kinetics are dose-independent over this range.
Esmolol dosing guideline:
An initial loading dose of 0.5 milligrams/kg (500 micrograms/kg) infused over a minute duration followed by a maintenance infusion of 0.05 milligrams/kg/min (50 micrograms/kg/min) for the next 4 minutes is recommended. This should give a rough guide with respect to the responsiveness of ventricular rate.
After the 4 minutes of initial maintenance infusion (total treatment duration being 5 minutes), depending upon the desired ventricular response, the maintenance infusion may be continued at 0.05 mg/kg/min or increased step-wise (e.g. 0.1 mg/kg/min, 0.15 mg/kg/min to a maximum of 0.2 mg/kg/min) with each step being maintained for 4 or more minutes.
If more rapid slowing of ventricular response is imperative, the 0.5 mg/kg loading dose infused over a 1 minute period may be repeated, followed by a maintenance infusion of 0.1 mg/kg/min for 4 minutes. Then, depending upon ventricular rate, another (and final) loading dose of 0.5 mg/kg/min infused over a 1 minute period may be administered followed by a maintenance infusion of 0.15 mg/kg/min. If needed, after 4 minutes of the 0.15 mg/kg/min maintenance infusion, the maintenance infusion may be increased to a maximum of 0.2 mg/kg/min.
In the absence of loading doses, constant infusion of a single concentration of esmolol reaches pharmacokinetic and pharmacodynamic steady-state in about 30 minutes. Maintenance infusions (with or without loading doses) may be continued for as long as 24 hour.
Esmolol (Brevibloc) - rxlist.com
Friday, December 5, 2008
Friday December 5, 2008
Is Traditional Reading of the Bedside Chest Radiograph Appropriate To Detect Intraatrial Central Venous Catheter Position?
Background:Traditionally, the positioning of central venous catheters (CVCs) outside the right atrium (RA) in patients receiving intensive care is determined by surrogate landmarks on bedside chest radiographs (CXRs). The validity of this method was examined by comparing readings of radiologists with the results of transesophageal echocardiography (TEE).
Methods: Prospective study at university hospital. Two hundred thirteen adults scheduled for cardiothoracic surgery were randomized to right or left internal jugular vein catheterization under ECG guidance. One senior radiologist and two radiologists in training independently read the CXRs, and determined whether the CVC tip ended in the RA and measured the vertical distance from the CVC tip to the carina (TC-distance).
Results:Two hundred twelve CVC tips could be identified by TEE. Only left-sided CVCs (n = 5) ended in the upper RA (2.4%). Three of those patients were shorter than 160 cm. Specificity was 94% for senior radiologist, 44% for the first radiologist in training, and 60% for the second radiologist in training. The TC-distance of intraatrial catheters was 39, 55, 59, 80, and 83 mm, respectively. Thus, a TC-distance 55 mm ensured extraatrial tip position in four of five intraatrial CVCs (80%, p = 0.002). The TC-distance of extraatrial catheters ranged from – 26 to 102 mm.
Conclusions: Reading of a bedside CXR alone is not very accurate to identify intraatrial CVC tip position. TC-distance is a helpful marker, and its specificity is as good as that of an experienced radiologist if a cutoff value of 55 mm is chosen.
Reference: click to get article
Is Traditional Reading of the Bedside Chest Radiograph Appropriate To Detect Intraatrial Central Venous Catheter Position? - Chest. 2008; 134:527-533
Is Traditional Reading of the Bedside Chest Radiograph Appropriate To Detect Intraatrial Central Venous Catheter Position?
Background:Traditionally, the positioning of central venous catheters (CVCs) outside the right atrium (RA) in patients receiving intensive care is determined by surrogate landmarks on bedside chest radiographs (CXRs). The validity of this method was examined by comparing readings of radiologists with the results of transesophageal echocardiography (TEE).
Methods: Prospective study at university hospital. Two hundred thirteen adults scheduled for cardiothoracic surgery were randomized to right or left internal jugular vein catheterization under ECG guidance. One senior radiologist and two radiologists in training independently read the CXRs, and determined whether the CVC tip ended in the RA and measured the vertical distance from the CVC tip to the carina (TC-distance).
Results:Two hundred twelve CVC tips could be identified by TEE. Only left-sided CVCs (n = 5) ended in the upper RA (2.4%). Three of those patients were shorter than 160 cm. Specificity was 94% for senior radiologist, 44% for the first radiologist in training, and 60% for the second radiologist in training. The TC-distance of intraatrial catheters was 39, 55, 59, 80, and 83 mm, respectively. Thus, a TC-distance 55 mm ensured extraatrial tip position in four of five intraatrial CVCs (80%, p = 0.002). The TC-distance of extraatrial catheters ranged from – 26 to 102 mm.
Conclusions: Reading of a bedside CXR alone is not very accurate to identify intraatrial CVC tip position. TC-distance is a helpful marker, and its specificity is as good as that of an experienced radiologist if a cutoff value of 55 mm is chosen.
Reference: click to get article
Is Traditional Reading of the Bedside Chest Radiograph Appropriate To Detect Intraatrial Central Venous Catheter Position? - Chest. 2008; 134:527-533
Thursday, December 4, 2008
Thursday December 4, 2008
Artificial intelligence in ICU !!
A very interesting study - "An artificial intelligence tool to predict fluid requirement in the intensive care unit: a proof-of-concept study" - is just published at ccforum.com
An alternative way of personalizing medicine in the ICU on a realtime basis by using information derived from the application of artificial intelligence on a high resolution database, is proposed. Calculation of maintenance fluid requirement at the height of systemic inflammatory response was selected to investigate the feasibility of this approach.
The Multi-parameter Intelligent Monitoring for Intensive Care II (MIMIC II) is a database of patients admitted to the Beth Israel Deaconess Medical Center ICU.
METHOD: Patients who were on vasopressors for more than 6 hours during the first 24 hours of admission were identified from the database. Demographic and physiologic variables that might affect fluid requirement or reflect the intravascular volume during the first 24 hours in the ICU were extracted from the database. The outcome to be predicted is the total amount of fluid given during the second 24 hours in the ICU, including all the fluid boluses administered.
Investigators represented the variables by learning a Bayesian network from the underlying data. Using ten-fold cross-validation repeated 100 times, the accuracy of the model in predicting the outcome is 77.8%. The network generated has a threshold Bayes factor of 7 representing the posterior probability of the model given the observed data. This Bayes factor translates into p < .05 assuming Gaussian distribution of the variables.
Conclusions: Based on the model, the probability that a patient will require a certain range of fluid on day 2 can be predicted. In the presence of a larger database, analysis may be limited to patients with identical clinical presentation, demographic factors, co-morbidities, current physiologic data, and those who did not develop complications as a result of fluid administration. By better predicting maintenance fluid requirements based on the previous day's physiologic variables, one might be able to prevent hypotensive episodes requiring fluid boluses during the course of the following day.
Reference: click to get article
An artificial intelligence tool to predict fluid requirement in the intensive care unit: a proof-of-concept study - Critical Care 2008, 12:R151 - pdf file
Artificial intelligence in ICU !!
A very interesting study - "An artificial intelligence tool to predict fluid requirement in the intensive care unit: a proof-of-concept study" - is just published at ccforum.com
An alternative way of personalizing medicine in the ICU on a realtime basis by using information derived from the application of artificial intelligence on a high resolution database, is proposed. Calculation of maintenance fluid requirement at the height of systemic inflammatory response was selected to investigate the feasibility of this approach.
The Multi-parameter Intelligent Monitoring for Intensive Care II (MIMIC II) is a database of patients admitted to the Beth Israel Deaconess Medical Center ICU.
METHOD: Patients who were on vasopressors for more than 6 hours during the first 24 hours of admission were identified from the database. Demographic and physiologic variables that might affect fluid requirement or reflect the intravascular volume during the first 24 hours in the ICU were extracted from the database. The outcome to be predicted is the total amount of fluid given during the second 24 hours in the ICU, including all the fluid boluses administered.
Investigators represented the variables by learning a Bayesian network from the underlying data. Using ten-fold cross-validation repeated 100 times, the accuracy of the model in predicting the outcome is 77.8%. The network generated has a threshold Bayes factor of 7 representing the posterior probability of the model given the observed data. This Bayes factor translates into p < .05 assuming Gaussian distribution of the variables.
Conclusions: Based on the model, the probability that a patient will require a certain range of fluid on day 2 can be predicted. In the presence of a larger database, analysis may be limited to patients with identical clinical presentation, demographic factors, co-morbidities, current physiologic data, and those who did not develop complications as a result of fluid administration. By better predicting maintenance fluid requirements based on the previous day's physiologic variables, one might be able to prevent hypotensive episodes requiring fluid boluses during the course of the following day.
Reference: click to get article
An artificial intelligence tool to predict fluid requirement in the intensive care unit: a proof-of-concept study - Critical Care 2008, 12:R151 - pdf file
Wednesday, December 3, 2008
Wednesday December 3, 2008
Sodium retention in Corticosteroids
Q; Which Corticosteroid has highest Relative Sodium Retension (RSR)?
- Choose one
A) Prednisone
B) Methylprednisone
C) Hydrocortisone
D) Dexamethasone
Answer: Hydrocortisone
Hydrocortisone has Relative Sodium Retention of "20" in comaprison to other steroids
Prednisone's RSR is 1
Methylprednisone RSR is 0.5
Dexamethasone RSR is 0
Sodium retention in Corticosteroids
Q; Which Corticosteroid has highest Relative Sodium Retension (RSR)?
- Choose one
A) Prednisone
B) Methylprednisone
C) Hydrocortisone
D) Dexamethasone
Answer: Hydrocortisone
Hydrocortisone has Relative Sodium Retention of "20" in comaprison to other steroids
Prednisone's RSR is 1
Methylprednisone RSR is 0.5
Dexamethasone RSR is 0
Tuesday, December 2, 2008
Tuesday December 2, 2008
Hepatic Hydrothorax
Q; How you confirm the cause of pleural effusion (mostly right sided) in cirrhotic patient as hepatic hydrothorax?
Answer: By radioisotope imaging (nuclear medicine)
Pleural effusion in cirrhotic patients (hepatic hydrothorax) may result from migration of ascitic fluid across defects in the diaphragm. Biochemical analysis of ascitic and pleural fluid provides only indirect information about the nature and origin of the effusion.
Transdiaphragmatic movement of ascitic fluid into the pleural space can be demonstrated, generally within 2 hours of intraperitoneal injection of the radiotracer ( 99mTc sulfur colloid scintigraphy).
Radionuclide scintigraphy is a simple, safe and relatively non-invasive method to confirm passage of ascitic fluid across the diaphragm.
Hepatic Hydrothorax
Q; How you confirm the cause of pleural effusion (mostly right sided) in cirrhotic patient as hepatic hydrothorax?
Answer: By radioisotope imaging (nuclear medicine)
Pleural effusion in cirrhotic patients (hepatic hydrothorax) may result from migration of ascitic fluid across defects in the diaphragm. Biochemical analysis of ascitic and pleural fluid provides only indirect information about the nature and origin of the effusion.
Transdiaphragmatic movement of ascitic fluid into the pleural space can be demonstrated, generally within 2 hours of intraperitoneal injection of the radiotracer ( 99mTc sulfur colloid scintigraphy).
Radionuclide scintigraphy is a simple, safe and relatively non-invasive method to confirm passage of ascitic fluid across the diaphragm.
Monday, December 1, 2008
Subscribe to:
Posts (Atom)