Q: How PEEP may contribute to induce pulmonary edema?

Answer:

PEEP may increase pulmonary edema by 2 factors

1, increasing intrathoracic pressure and

2, decreasing outflow of lymph

Q: Is it necessary to use heparinized saline in pressure bag for arterial line monitoring?


Answer: No

Previously, it was a standard to use heparinized saline to use with pressure bag during arterial line monitoring. But recent guidelines suggest NOT to use heaprinized saline. Simple saline is equally good for flushing blood and medications through arterial lines, and it poses minimal risk of causing adverse drug events like potential HIT (Heparin Induced Thrombocytopenia).

References:

1. Eliminate the Use of Heparin Solution with Arterial Lines - ihi.org recommendations, last update 04/23/2011

2. Whitta RK, Hall KF, Bennetts TM, Welman L, - Comparison of normal or heparinised saline flushing on function of arterial lines., Crit Care Resusc. 2006 Sep;8(3):205-8.

Q: What bacteria E.coli has to do with Filgrastim (Neupogen)?

Answer:

Filgrastim  (Neupogen) is a granulocyte colony-stimulating factor (G-CSF) analog used to stimulate the proliferation and differentiation of granulocytes. It is produced by recombinant DNA technology.

The gene for human granulocyte colony-stimulating factor is inserted into the genetic material of Escherichia coli. The G-CSF then produced by E. coli is different from G-CSF naturally made in humans.

Q; What are the 3 catheter based interventions to perform mechanical thrombectomy in massive/submassive pulmonary embolism?


Answer: 

Broadly there are 3 categories of percutaneous catheter intervention in pulmonary emboli:

1. Aspiration thrombectomy,
2. Thrombus fragmentation,
3. Rheolytic thrombectomy*

Mechanical thrombectomy should be avoided beyond the main and lobar pulmonary arterial branches. Direct intra-arterial delivery of thrombolytics, may be helpful if mechanical thrombectomy is ineffective.

*Rheolytic thrombectomy catheters use a high-velocity saline jet to fragment adjacent thrombus by creating a Venturi effect.

References:

Fava M, Loyola S. Applications of percutaneous mechanical thrombectomy in pulmonary embolism. Tech Vasc Interv Radiol. 2003; 6: 53–58.

Cho KJ, Dasika NL. Catheter technique for pulmonary embolectomy or thrombofragmentation. Semin Vasc Surg. 2000; 13: 221–235.

Kucher N, Windecker S, Banz Y, Schmitz-Rode T, Mettler D, Meier B, Hess OM. Percutaneous catheter thrombectomy device for acute pulmonary embolism: in vitro and in vivo testing. Radiology. 2005; 236: 852–858

Q; What is the significance of increased Troponin in Pulmonary Embolism?

Answer: 

In acute pulmonary embolism, troponins probably rise because of acute right heart overload. The release is of shorter duration than in unstable angina, and the peak level is linked to the outcome.

References:

1. Müller-Bardorff M, Weidtmann B, Giannitsis E, et al. Release kinetics of cardiac troponin T in survivors of confirmed severe pulmonary embolism. Clin Chem. 2002; 48: 673–675.

2. Giannitsis E, Müller-Bardorff M, Kurowski V, et al. Independent prognostic value of cardiac troponin T in patients with confirmed pulmonary embolism. Circulation. 2000; 102: 211–217

Q; Which test would be better in predicting septic arthritis?

Answer:  CRP

An elevated CRP (C-reactive protein) is helpful in determining the presence of a septic joint. The ESR and CRP are almost always raised on admission, CRP being more specific in diagnostics. Both elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) is useful in following response to therapy.

 

Reference: Usefulness of CRP and ESR in predicting septic joints South Med J. 2010 Jun;103(6):522-6.  

Q; Tumor lysis syndrome may cause all except? (Choose one)

A) Hyperkalemia

B) Hyperphosphatemia

C) Hypercalcemia

D) Hyperuricemia

E) Lactic acidosis

Answer:  C

Tumor lysis syndrome cause Hypocalcemia. Because of the hyperphosphatemia, calcium is precipitated to form calcium phosphate, leading to hypocalcemia. Hypocalcemia may lead to tetany, seizures etc.

Patients about to receive chemotherapy for a cancer with a high cell turnover rate, like lymphomas and leukemias, should receive prophylactic allopurinol as well as IV hydration to target urine output > 2.5 L/day. Rasburicase is an alternative to allopurinol. Alkalization of the urine is controversial and has shown no difference.

Q; Which tumors are more prone to give negative cytology in malignant pleural effusion?

Answer:

Generally cytology is positive only in approximately 60 percent of malignant pleural effusions, but following tumors are more prone to have negative cytology.

• mesothelioma,
• sarcoma, and
• lymphoma

Other factors which effects the cytology of malignant effusion are the tumor burden in the pleural space, amount of pleural fluid submitted and the expertise of the cytologist.

Usually 10 mL of pleural fluid should be adequate for cytologic processing.

References:

1. Maskell NA, Butland RJ, Pleural Diseases Group, Standards of Care Committee, British Thoracic Society. BTS guidelines for the investigation of a unilateral pleural effusion in adults. Thorax. 2003;58(suppl 2):ii8–17.

2. Sallach SM, Sallach JA, Vasquez E, Schultz L, Kvale P. Volume of pleural fluid required for diagnosis of pleural malignancy. Chest. 2002;122:1913–7.

Septic Pulmonary Emboli

  

Septic pulmonary emboli is embolization of intravascular thrombus containing microorganisms into the lungs. Septic emboli can occur from varying sources like tricuspid valve endocarditis, infection elsewhere in the body with associated septal defect, infected deep venous thrombosis, venous lines / central venous catheters, pacemaker wires etc.

On CT chest, "vessel sign" is interesting to watch with peripheral nodules with clearly identifiable feeding vessels. May be visible are - subpleural nodular lesions or wedge-shaped densities with or without necrosis caused by septic infarcts.

CPAP vs Bi-PAP ventilation

(Basics)

Source: http://youtu.be/BdeOiDJmbrk

Q: Which lung cancer is more prone to produce Syndrome of Inappropriate Antidiuretic Hormone (SIADH)?

Answer: Small cell lung cancer

SIADH is associated with a number of malignancies but most notably with small-cell lung cancer.

SIADH can also occur following head injury, following neck dissection and manipulation of the nervous system, few drugs like morphine, NSAIDs etc and in a number of  other pulmonary processes like pneumonia, abscess, and tuberculosis. It can also occur with endocrine diseases like hypothyroidism and glucocorticoid deficiency.

Q: What is clinical importance of Mayo-Robson point?

Answer:

A point just above and to the right of the umbilicus is called Mayo-Robson's point. At this point the tail of pancreas is projected on the abdominal wall. Here tenderness on pressure exists in diseases of the pancreas and it is a one clinical sign in acute pancreatitis.

 LEMON for Airway intubation

Some providers use the LEMON pneumonic to help them assess an airway

L- Look externally (facial trauma, teeth, facial hair, etc.)

E- Evaluate thyromental distance

M- Mallampati Class

O- Obstruction (airway edema, tracheal mass, mediastinal mass, etc.)

N- Neck mobility

Q: What is large bore IV?

Answer: At least 16 gauge  and ideally 12-14 gauge.

As contrary to popular belief and practice central line is not a large bore or resuscitation line.

Rapid infusion of volume is based on basic physics of Hagen-Poiseuille equation. As per Hagen-Poiseuille equation just 2 fold increase in radius increase flow by 16 fold but 2 fold increase in length decrease flow by 50%.

Technically regularly available central lines (TLC or PICC line) is not ideal for IVF bolus due to longer length and smaller radius. 2 Large bore (say 16 gauge) peripheral IVs or one large bore central short IV (cordis) are real placements for aggressive resuscitation (due to bigger radius and shorter length).

Point is: Central line or two 18 G peripherals should not be labeled as large bore IVs.

Q: 17 year old male is admitted with bloody diarrhea and vomiting. Patient visited petting zoo 3 days ago with his friend. Now patient is hypotensive, no urine out put and altered mental status. Probable diagnosis?

Answer: HUS

Hemolytic Uremic syndrome (HUS) should be high on list with bloody diarrhea after visit to petting zoo. Other risk factors include contamination via hamburger or contact to infected person.

• The GI symptoms usually starts after 4-6 days. Diarrhea typically become hemorrhagic and may quickly set into septic shock.

Antibiotics are usually not required, actually discouraged. Minor cases can be treated with supportive treatment but in cases like above plasma exchange (plasmapheresis combined with fresh-frozen plasma replacement) is currently the treatment of choice.

Q: Ideally, mature Arterio-Venous Fistula (AVF) for hemodialysis should have which basic properties?

Answer:

Ideally, mature AVF should have the following characteristics to be safely punctured:

1. discernible vein margins,

2. flow greater than 600 mL/min,

3. vein diameter at least 0.6 cm and

4. should be located no more than 0.6 cm deep

Y. C. Kim, J. Y. Won, S. Y. Choi, H. K. Ko, K. H. Lee, Y. do Lee, B. C. Kang, S. J. Kim, 2009 Percutaneous treatment of central venous stenosis in hemodialysis patients: long-term outcomes. Cardiovasc Intervent Radiol 32 2 271 278

Q: 54 year old male who is POD # 22 heart transplant is found to have symptomatic bradycardia with heart rate of 24. Resident administered 3 mg of Atropine without any effect. Your explanation?

Answer:  

Atropine is ineffective and should be avoided in heart transplant patients. The vagus nerve is not retransplanted after transplant and so Atropine would be useless in symptomatic bradycardia.

The transplanted heart is able to function in its new host through the capacity of its intact, intrinsic nervous system.The heart's nervous system contains around 40,000 neurons, called sensory neurites, which detect circulating hormones and neurochemicals and sense heart rate and pressure information. Hormonal, chemical, rate and pressure information is translated into neurological impulses by the heart's nervous system and sent from the heart to the medulla in brain through several afferent pathways. The signals have a regulatory role over many of the autonomic nervous system signals that flow out of the brain to the heart, blood vessels and other glands and organs.

Murphy D A, Thompson G W, et al (2000), The heart reinnervates after transplantation. Annals of Thoracic Surgery; 69(6): 1769-1781.

Q: 36 year old female is in ICU with septic shock and diagnosed with strongyloidiasis. She also has severe GI ileus and was made NPO . She is on ivermectin. What is your option to administer her essential treatment? 


Answer: Rectal or SC administration of Ivermectin 

 Ivermectin is the drug of choice for strongyloidiasis. It is usually given as PO with empty stomach but if PO route is note feasible, it can be given rectally or even as SC administration. 



 Fusco DN, Downs JA, Satlin MJ, Pahuja M, Ramos L, Barie PS, et al. Non-oral treatment with ivermectin for disseminated strongyloidiasis. Am J Trop Med Hyg. Oct 2010;83(4):879-83

Q: What is "botulinum cook" ?

Answer:

Botulinum toxin is destroyed by proper thorough cooking but the spore itself is not killed by the temperatures at normal boiling. Spores may grow again when conditions are right. All commercially canned goods are required to undergo a "botulinum cook" in a pressure cooker at 121 °C (250 °F) for 3 minutes, which most likely will kill spores.

Clinically most important thing to remember besides history taking is - paralysis is usually in descending fashion, starting from cranial nerves downward towards arms and legs. It also may effect respiratory muscles. Initial symptoms are double vision, drooping of both eyelids, loss of facial expression, swallowing  and speech  problems. The weakness then spreads - starting in the shoulders and proceeding to the forearms - and again - from the thighs down to the feet.

Most updated review we found on Botulism is at Medscape website, Click here 

http://emedicine.medscape.com/article/213311-overview

Q: 28 year old male, who just returned from Bangladesh 2 days ago presented to ED with vomiting, painless but profuse "rice water" type diarrhea - almost 20 liter/day! which smells like fish. On examination patient skin seems turning a bluish-gray hue. Your concern?

 

Answer: Cholera

The hallmark of cholera is profuse, painless diarrhea and vomiting of clear fluid. Clinical symptoms starts from few hours upto five days after ingestion of the bacteria. The diarrhea is clasically described as "rice water" with fishy odor. Patient may produce 10 to 20 litres of diarrhea a day. Cholera has been nicknamed the "blue death" due to a patient's skin turning a bluish-gray hue from massive dehydration.

Doxycycline is the first line of agent for treatment, followed by cotrimoxazole, erythromycin, tetracycline, chloramphenicol,and furazolidone. Fluoroquinolones, such as norfloxacin, also may be used.

Adenosine and limbs numbness

 Adenosine can make patients' limbs feel numb for about 2–5 minutes after intravenous administration particularly when total administration is above 12 mg.

Taste disturbances with captopril

Captopril though not much in use in USA is a well known and frequently used ACE inhibitor in many developing countries, due to its availability in generic form and cost effectiveness.

Taste disturbances which is infrequent with most ACE inhibitors, are more prevalent in captopril. This is attributed to its sulfhydryl moiety.  Altered taste sensation may include loss of taste perception, persistent salt  taste or persistent metallic taste.

Fenoldopam and Beta blocker

Fenoldopam is an antihypertensive agent, which acts as a selective D1 receptor partial agonist.

Fenoldopam's concomitant use with a beta-blocker should be avoided if possible. Unexpected hypotension can result from beta-blocker inhibition of sympathetic-mediated reflex tachycardia in response to fenoldopam.

Causes of Hemoptysis

Causes of Hemoptysis & Diffuse Aveolar Hemmorhage can be remembered with folllowing mnemonic 

BATTLE CAMP

• Bronchitis, Bronchiectasis
• AVMs
• Tumor, Trauma
• Tuberculosis
• LV dysfunction
• Emboli (PE)
• Connective Tissue Disease (Wegener's, Goodpasture's,etc), Coagulopathy
• Abscess, Aspergilloma, Alveolar hemorrhage
• Mitral Stenosis
• Pneumonia

Happy Birthday America

 May this flag fly high forever

Cocaine overdose and Rimcazole

Cocaine overdose causes tachyarrhythmias and life-threatening hypertensive crisis. Moreover, Cocaine is very pyrogenic due to increased muscular activity and inhibited heat loss due to severe vasoconstriction.

Treatment of Cocaine overdose consists of administering a benzodiazepine, physical cooling, acetaminophen, non-beta-blocker treatment for hypertension and other supportive treatments.

Though not officially approved, dexmedetomidine and rimcazole have been found to be useful for treating cocaine overdose.

Rimcazole is an antagonist of the sigma receptor as well as is a dopamine reuptake inhibitor. Sigma receptors are thought to be involved in the psychosis that can be induced by some drugs such as PCP and cocaine. Rimcazole was originally researched as a potential antipsychotic but found to reduce the effects of cocaine.

References:

1. Katz JL, Libby TA, Kopajtic T, Husbands SM, Newman AH. Behavioral effects of rimcazole analogues alone and in combination with cocaine. European Journal of Pharmacology. 2003 May 9;468(2):109-19.

2. Matsumoto RR, Hewett KL, Pouw B, Bowen WD, Husbands SM, Cao JJ, Hauck Newman A. Rimcazole analogs attenuate the convulsive effects of cocaine: correlation with binding to sigma receptors rather than dopamine transporters. Neuropharmacology. 2001 Dec;41(7):878-86.

Acute abdomen in DKA

Q: One of the most deceiving sign in DKA (Diabetic ketoacidosis) is acute abdomen. Which factors are commonly associated with acute abdomen in DKA ?

Answer:

1. Severity of Metabolic Acidosis
2. History of Cocaine abuse
3. History of alcohol abuse

Interestingly severity of dehydration and hyperglycemia is not found to be an associated factor in this type of presentation.

Reference:

Umpierrez G, Freire AX. - Abdominal pain in patients with hyperglycemic crises. J Crit Care. 2002 Mar;17(1):63-7

False positive or false negative stool guaiac test

Q: What can turn stool guaiac test false positive or false negative?

Answer:

False positive:

• Iron supplements,
• Bismuth containing products
• Red meat (the blood it contains can turn the test positive), 
• Many vegetables particularly if raw like cucumber, cauliflower and horseradish, which contain a chemical with peroxidase properties that can turn the test positive. 

False negative:

• Vitamin C and citrus fruits (which can turn the test falsely negative) 

References:

1. Beg M, et al. (2002). "Occult Gastrointestinal Bleeding: Detection, Interpretation, and Evaluation" JIACM 3 (2): 153–8.
2. Jaffe RM, Kasten B, Young DS, MacLowry JD (December 1975). "False-negative stool occult blood tests caused by ingestion of ascorbic acid (vitamin C)". Ann. Intern. Med. 83 (6): 824–6.
3. Anderson GD, Yuellig TR, Krone RE (May 1990). "An investigation into the effects of oral iron supplementation on in vivo Hemoccult stool testing". Am. J. Gastroenterol. 85 (5): 558–61.
4. Wells HJ, Pagano JF (1977). "Hemoccult test — reversal of false-negative results due to storage". Gastroenterology 72: 1148.