Saturday December 5, 2009
Q: What is Haldane effect?
Answer: The Haldane effect (named after John Scott Haldane) describe that deoxygenation of the blood increases its ability to carry carbon dioxide. Conversely, oxygenated blood has a reduced capacity for carbon dioxide.
The Haldane effect promotes dissociation of carbon dioxide from hemoglobin in the presence of oxygen. In the oxygen-rich capillaries of the lung, this property causes the displacement of carbon dioxide to plasma as venous blood enters the alveolus and is vital for alveolar gas exchange.
This partially explains the observation that some patients with emphysema might have an increase in PaCO2 following administration of supplemental oxygen even if content of CO2 stays equal.
Oxygenation of Hb promotes dissociation of H+ from Hb, which shifts the bicarbonate buffer equilibrium towards CO2 formation; therefore, CO2 is released from RBCs.
Saturday, December 5, 2009
Friday, December 4, 2009
Friday December 4, 2009
Pulmonary Artery Catheter in Amniotic fluid embolism !!
20 years ago it was suggested by Mason that probable diagnosis of Amniotic fluid embolism can be made by analyzing pulmonary artery blood with the logic that amniotic fluid does not ordinarily enter the maternal circulation, and the identification of large numbers of fetal squamous in the postpartum pulmonary microvasculature is of clinical significance. (He applied similar argument for other similar diseases such as fat embolism). Diagnosis becomes more probable if other fetal debris such as mucin or hair is present.
Technique described: Obtain blood from the distal lumen of a pulmonary artery catheter (in wedged position). After discarding the first 10 ml of blood, draw an additional 10 ml, heparinize and analyze utilizing Papanicolaou's method.Above technique is only suggestive of amniotic fluid embolism and not a gold standard.
Power Point Presentation: AMNIOTIC FLUID EMBOLISM
References: Click to get abstract/article
1. Pulmonary microvascular cytology. A new diagnostic application of the pulmonary artery catheter - Chest, V. 88, 908-14
2. Amniotic fluid embolism - Masson RG - Clin Chest Med.1992 Dec;13(4):657-65.
Pulmonary Artery Catheter in Amniotic fluid embolism !!
20 years ago it was suggested by Mason that probable diagnosis of Amniotic fluid embolism can be made by analyzing pulmonary artery blood with the logic that amniotic fluid does not ordinarily enter the maternal circulation, and the identification of large numbers of fetal squamous in the postpartum pulmonary microvasculature is of clinical significance. (He applied similar argument for other similar diseases such as fat embolism). Diagnosis becomes more probable if other fetal debris such as mucin or hair is present.
Technique described: Obtain blood from the distal lumen of a pulmonary artery catheter (in wedged position). After discarding the first 10 ml of blood, draw an additional 10 ml, heparinize and analyze utilizing Papanicolaou's method.Above technique is only suggestive of amniotic fluid embolism and not a gold standard.
Power Point Presentation: AMNIOTIC FLUID EMBOLISM
References: Click to get abstract/article
1. Pulmonary microvascular cytology. A new diagnostic application of the pulmonary artery catheter - Chest, V. 88, 908-14
2. Amniotic fluid embolism - Masson RG - Clin Chest Med.1992 Dec;13(4):657-65.
Thursday, December 3, 2009
Thursday December 3, 2009
Q: What is Scombroidosis?
Answer: Scombroidosis refers to histamine poisoning from the ingestion of fish improperly stored at an elevated temperature. Histamine and cis-urocanic acid are produced by various bacteria that multiply in the spoiled fish.
Patients usually present with a frightening flush but no urticaria, palpitations, syncope, nausea, vomiting, or diarrhea.
Q: What is Scombroidosis?
Answer: Scombroidosis refers to histamine poisoning from the ingestion of fish improperly stored at an elevated temperature. Histamine and cis-urocanic acid are produced by various bacteria that multiply in the spoiled fish.
Patients usually present with a frightening flush but no urticaria, palpitations, syncope, nausea, vomiting, or diarrhea.
Wednesday, December 2, 2009
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