hypothyroidism and statin-induced myopathy

 Q; Why patients with a history of hypothyroidism are more susceptible to have statin-induced myopathy?

Answer:  There are two suggested mechanisms to explain hypothyroidism related statin-induced myopathy. Hypothyroidism causes dyslipidemia. Most of the statins are lipophilic which leads to statin-induced myopathy. Another reason is the possibility that the use of statins may "unmask" the covert hypothyroid myopathy. It would be wise to treat hypothyroidism prior to initiate statin therapy. Similarly, vitamin D should also be replenished at an appropriate level to decrease the risk of myopathy from the statins. 

#endocrine

#pharmacology

References:

1. al-Jubouri MA, Briston PG, Sinclair D, et al. Myxoedema revealed by simvastatin induced myopathy. BMJ 1994; 308:588. 

2. Khayznikov M, Hemachrandra K, Pandit R, et al. Statin Intolerance Because of Myalgia, Myositis, Myopathy, or Myonecrosis Can in Most Cases be Safely Resolved by Vitamin D Supplementation. N Am J Med Sci 2015; 7:86.  

TLS ansd diuretics

 Q: Which Diuretic is preferred in patients with Tumor Lysis Syndrome if required? (select one)

A: bumetanide 

B) furosemide 

 

Answer: B 

 Patients undergoing TLS usually don't require diuretics and intravenous hydration should be enough. But a large number of chemotherapy patients have either cardiac or/and renal dysfunction and may require diuretics to keep urine output (U-OP) 80-100 cc/hour, a usual target of U-OP in TLS. Loop diuretics (furosemide) is preferred as it also helps to reduce the risk of hyperkalemia by increasing potassium excretion. TLS is considered an oncologic emergency. ICU admission is highly desirable. It releases a large amount of potassium, phosphate, and nucleic acids (subsequently converted to uric acid) into the systemic circulation.

#oncology

Reference:

1. Mirrakhimov AE, Voore P, Khan M, Ali AM. Tumor lysis syndrome: A clinical review. World J Crit Care Med. 2015;4(2):130-138. Published 2015 May 4. doi:10.5492/wjccm.v4.i2.130 2. 

2. Howard SC, Jones DP, Pui CH. The tumor lysis syndrome [published correction appears in N Engl J Med. 2018 Sep 13;379(11):1094]. N Engl J Med. 2011;364(19):1844-1854. doi:10.1056/NEJMra0904569

fluorescence bronchoscopy

 Q; What purpose fluorescence bronchoscopy serves? 

 Answer: Biologically abnormal tissue such as precancerous lesions, particularly squamous cell dysplasias lose their fluorescent property. Auto-fluorescence bronchoscopy (AFB) is used to detect them. It can be used with a regular bronchoscope where a bronchoscope can switch fluorescent and white light modes.

 AFB scopes highlight differences in red and green fluorescence from the tissues. Squamous dysplasia, carcinoma in situ (CIS), and microinvasive carcinoma have much weaker green fluorescence and slightly weaker red fluorescence than normal tissues at a wavelength of 380 to 440 nm (blue spectrum). 

This decrease in florescence activity is probably due to increased epithelial thickness, and neovascularization. AFB is so far has been utilized to identify lesions at risk of progression to invasive squamous cell carcinoma only. Its utility is not much of value for metastatic or adeno carcinomas.  

#procedures

#pulmonary

References:

1. Hung J, Lam S, LeRiche JC, Palcic B. Autofluorescence of normal and malignant bronchial tissue. Lasers Surg Med 1991; 11:99. 

2. Qu J, MacAulay C, Lam S, Palcic B. Mechanisms of ratio fluorescence imaging of diseased tissue. Society of Photo-optical Instrumentation Engineers 1995; 2387:71.

MG and drugs

 Q: Which of the following class of cardiac drugs be used with caution in Myasthenia Gravis (MG)? (select one)

A) Beta Blockers (BB)

B) Calcium Channel Blockers (CCB)

Answer: A

Potentially any drug can exacerbate MG. The most notorious and well known are aminoglycosides, fluoroquinolone, and neuromuscular blocking agents, which are used frequently in ICUs. For clinicians working in ICU, it should be noted that any respiratory depressants like benzodiazepines, opioids, or sedatives can have an exacerbated effect on patients with MG causing unnecessary need for mechanical ventilation. 

Magnesium sulfate is one of the most reflexly ordered electrolyte replacement in ICU, as well as found in many over the counter multi-vitamin bottles. Patients with MG should not be a part of an electrolyte protocol in ICU.

Patients in oncology service/ICU may not be candidates of Programmed cell death 1 (PD-1) inhibitors. They can trigger autoimmune MG. 

 Many patients with MG have simultaneous cardiac diseases. All beta-blockers and procainamide should be used with caution in these patients. These patients can be prescribed statins but with very close monitoring and watching risk/benefit ratio between cardiac and MG risks.

#neurology

#cardiology

#pharmacology

References:

1. A Ahmed, Z Simmons. Drugs Which May Exacerbate or Induce Myasthenia Gravis: A Clinician's Guide. The Internet Journal of Neurology. 2008 Volume 10 Number 

2. Mehrizi M, Fontem RF, Gearhart TR, Pascuzzi RM. Medications and Myasthenia Gravis (A Reference for Health Care Professionals), Indiana University School of Medicine (Department of Neurology), 2012. 

3. Dillon FX. Anesthesia issues in the perioperative management of myasthenia gravis. Semin Neurol 2004; 24:83. 

4. Khalid R, Ibad A, Thompson PD. Statins and Myasthenia Gravis. Muscle Nerve 2016; 54:509.

acute abdominal pain with forceful evacuation of bowel.

 Q: 65 year old male presented to ED with abdominal pain. Patient described his pain as acute around the periumbilical region, associated with nausea and vomiting. Patient also described his pain first occurs with forceful evacuation of bowel. On exam, patient's pain appears way out of proportion to findings. What could be the probable etiology?

Answer: Acute mesenteric ischemia 

​The clinical exam can be very deceiving in acute mesenteric ischemia and requires a high index of suspicion. In the early stages of presentation, pain is usually way out of proportion to physical findings. Abdominal distension, rebound tenderness, and guarding are relatively late signs. Association with rapid and forceful bowel evacuation should raise a high suspicion especially in males above 60 years of age. Risk factors are advanced age, atherosclerosis, history of smoking, and cardiac disease, particularly atrial fibrillation.

#surgical-critical-care

References:

1. Oldenburg WA, Lau LL, Rodenberg TJ, Edmonds HJ, Burger CD. Acute Mesenteric Ischemia: A Clinical Review. Arch Intern Med. 2004;164(10):1054–1062. doi:10.1001/archinte.164.10.1054

2. Monita MM, Gonzalez L. Acute Mesenteric Ischemia. [Updated 2020 Jun 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK431068/

HIV prompt treatment

Q: 44-year-old male is admitted to ICU with sepsis. Patient gets diagnosed with HIV. Prompt treatment of HIV applies to the start of antiretroviral therapy (ART) within which period of time? (select one)

A) same day
B) within three days
C) within a week


Answer: A

Prompt treatment for HIV applies to the initiation of ART on the same day of diagnosis if resources allow. In this regard, the availability of starter packs of an antiretroviral regimen is extremely important. Studies have shown that this approach is associated with higher adherence to treatment, decrease transmission, and most importantly a more rapid time for virologic suppression without major adverse effects. 

#infectious-diseases 


References:

1. Pilcher CD, Ospina-Norvell C, Dasgupta A, et al. The Effect of Same-Day Observed Initiation of Antiretroviral Therapy on HIV Viral Load and Treatment Outcomes in a US Public Health Setting. J Acquir Immune Defic Syndr 2017; 74:44. 

2. United States Department of Health and Human Services. Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents Living with HIV. https://aidsinfo.nih.gov/guidelines/html/1/adult-and-adolescent-arv/0 (Accessed on August 24, 2020).

Hyperglycemia in ICU

Q: Hyperglycemic response to dextrose containing fluid infusion in ICU patients is usually exaggerated. What are the reasons behind it?

Answer:  It is not a surprise that infusion of dextrose-containing solutions can cause hyperglycemia, but this response is exaggerated particularly in ICU patients. This is due to two other added mechanisms.

1. counter-regulatory hormone response i.e. increased epinephrine secretion. 
2. cytokine responses

These all combined effect leads to hyperglycemia much higher than expected.


#electrolyte
#endocrine


References:

1. McCowen KC, Malhotra A, Bistrian BR. Stress-induced hyperglycemia. Crit Care Clin 2001; 17:107. 

2. Wolfe RR, Allsop JR, Burke JF. Glucose metabolism in man: responses to intravenous glucose infusion. Metabolism 1979; 28:210.

zones of the retroperitoneum

Q: There are how many zones of the retroperitoneum?

Answer: Three

The retroperitoneum is divided into three zones which are used to describe the location of retroperitoneal hematomas. 

●Zone 1 is the central retroperitoneum, extending from the diaphragm superiorly to the bifurcation of the aorta inferiorly. The aorta, the inferior vena cava, the origins of the renal and major visceral vessels, a portion of the duodenum, and the pancreas lies in this zone. 

●Zone 2 includes both of the lateral perinephric areas of the upper retroperitoneum from the renal vessels medially to the lateral reflection of posterior parietal peritoneum of the abdomen, and extending from the diaphragm superiorly to the level of the aortic bifurcation inferiorly. Zone 2 contains the adrenal glands, the kidneys, the renal vessels, the ureters, and the ascending and descending colon. It is usually not contiguous. 

●Zone 3 is inferior to the aortic bifurcation and includes the right and left internal and external iliac arteries and veins, the distal ureter, the distal sigmoid colon, and the rectum.

#trauma


References:

1. Feliciano DV. Management of traumatic retroperitoneal hematoma. Ann Surg 1990; 211:109.


2. Bageacu S, Kaczmarek D, Porcheron J. Conduite à tenir devant un hématome rétro-péritonéal d'origine traumatique [Management of traumatic retroperitoneal hematoma]. J Chir (Paris). 2004;141(4):243-249. doi:10.1016/s0021-7697(04)95603-7

treatment of achalasia

Q: Out of the following which is considered a relatively effective treatment of achalasia? 

A) isosorbide dinitrate 
B) sildenafil 
C) dicyclomine 
D) terbutaline 
E) theophylline


Answer: A 

 Surgical procedures including botulinum toxin injection remain the mainstay of treatment for achalasia. For patients who are not candidates for this, many pharmacological treatments have been proposed. Out of all, sublingual isosorbide dinitrate 10-15 minutes prior to a meal is considered the most effective. The dose is 5 mg. If isosorbide dinitrate is not available (as in the USA) sublingual nitroglycerin in a dose of 0.4 mg can be used. Side effects are headache and flushing.  

5-phosphodiesterase inhibitors (sildenafil), anticholinergics (atropine, dicyclomine, cimetropium bromide), beta-adrenergic agonists (terbutaline), and theophylline have been tried but so far failed to show any successful results. Short-acting Calcium Channel blockers have been proposed but should be avoided as it can cause hemodynamic collapse.

#surgical-critical-care
#gastroenterology


References:

1. Wen ZH, Gardener E, Wang YP. Nitrates for achalasia. Cochrane Database Syst Rev 2004; :CD002299. 

2. Kahrilas PJ, Pandolfino JE. Treatments for achalasia in 2017: how to choose among them. Curr Opin Gastroenterol 2017; 33:270. 

Meperidine

Q: Meperidine can have which effect? (select one) 

A) Dysphoria 
B) Euphoria


Answer:

Physicians may get into the cognitive bias that the patients who are requesting meperidine are looking for euphoria. On the contrary, meperidine can cause distressing dysphoria. In ICU it should be used with caution as due to its well-known toxic metabolite normeperidine, which has serotonergic properties, and drug-drug interaction it has a high risk of causing serotonin syndrome and seizure.

#pharmacology


References:

1. Latta KS, Ginsberg B, Barkin RL. Meperidine: a critical review. Am J Ther 2002; 9:53.

2. Yasaei R, Rosani A, Saadabadi A. Meperidine. [Updated 2020 May 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470362/

Gabapentin overdose

Q: 52 year old male with Chronic Kidney Disease stage 4 is transferred from medical floor to ICU due to obtundation. There is a suspicion of an overdose of Gabapentin due to drug error on the floor. Patient required intubation for protection of the airway. CT Head reported negative. What is your next line of action?


Answer: Hemodialysis

Gabapentin should be given with caution in patients with renal insufficiency. Actually proper Cockcroft Gault formula should be applied for calculation of the dose. It should be sufficient to give 200 to 300 mg of gabapentin after 4 hours of each hemodialysis session in End-Stage Renal Disease (ESRD) patients if prescribed.

#pharmacology


Reference:

Wong MO, Eldon MA, Keane WF, et al. Disposition of gabapentin in anuric subjects on hemodialysis. J Clin Pharmacol. 1995;35(6):622-626. doi: 10.1002/j.1552-4604.1995.tb05020.x

MM clinical spectrum

Q: 66 year old male with multiple myeloma (MM) is admitted to ICU with mental status change. Which of the following is more common in patients with MM? (select one)

A) Anemia 
B) Hypercalcemia


Answer: A

The objective of the above question is to emphasize that though hypercalcemia is considered synonymous with MM, there are other abnormalities that may be more common. One of the largest retrospective studies looking into the clinical spectrum of MM was done at Mayo in 2003 counting more than 1000 patients. It found the following frequency

• Anemia - 73 percent 
• Bone pain - 58 percent 
• Elevated creatinine - 48 percent 
• Fatigue/generalized weakness  - 32 percent 
• Hypercalcemia -28 percent
• Weight loss - 24 percent
• Paresthesias - 5 percent
• Hepatomegaly - 4 percent
• Splenomegaly  - 1 percent
• Lymphadenopathy - 1 percent, and 
• Fever - 0.7 percent

#hematology

#electrolytes

Reference:

Kyle RA, Gertz MA, Witzig TE, et al. Review of 1027 patients with newly diagnosed multiple myeloma. Mayo Clin Proc 2003; 78:21.

wandering spleen

Q: 34 year old soccer player is admitted with acute right-sided abdominal pain. CT scan report described wandering spleen. What is wandering spleen?

Answer: Wandering spleen also known as the ectopic spleen, where spleen migrates to another location in the abdomen. This is due to either laxity or maldevelopment (congenital) of the supporting ligaments. Abdominal pain can be acute, chronic, or intermittent pain. Pain is probably due to the torsion of the wandering spleen. Removal of the spleen is recommended as it may cause life-threatening complications including splenic infarction, portal hypertension, and hemorrhage. Splenopexy has been described but is not preferred as recurrence or complications are common.

#surgical-critical-care


Reference:

1. Gayer G, Hertz M, Strauss S, Zissin R. Congenital anomalies of the spleen. Semin Ultrasound CT MR 2006; 27:358. 

2. Faridi MS, Kumar A, Inam L, Shahid R. Wandering Spleen- A diagnostic Challenge: Case Report and Review of Literature. Malays J Med Sci. 2014;21(6):57-60. 

3. Stringel G, Soucy P, Mercer S. Torsion of the wandering spleen: splenectomy or splenopexy. J Pediatr Surg. 1982;17(4):373–375.

BB in VT storm

Q: In patients with electrical storm or incessant Ventricular Tachycardia, along with amiodarone which beta-blocker is preferred? 

A) Metoprolol 
B) Propranolol 


 Answer: B 

 Beta-blockers reduce the adrenergic surge associated with ventricular tachyarrhythmias (VT-storm) and due to defibrillator shocks. Propranolol which is a nonselective beta-blocker is found to be more effective than beta-1 selective metoprolol. Propranolol is found to terminate VT significantly earlier than metoprolol. Also, it may decrease the incidences of implantable cardioverter-defibrillator (ICD) shocks.

#cardiology


References:

1. Gorenek B, Blomström Lundqvist C, Brugada Terradellas J, et al. Cardiac arrhythmias in acute coronary syndromes: position paper from the joint EHRA, ACCA, and EAPCI task force. Europace 2014; 16:1655.

2. Eifling M, Razavi M, Massumi A. The evaluation and management of electrical storm. Tex Heart Inst J 2011; 38:111.

MTX induced neurotoxicity

Q: 32 year old female is admitted to ICU with seizures after Methotrexate (MTX) treatment. Can MTX can be prescribed to her again in the future? (select one)

A) Yes
B) No


Answer: A

Neurotoxicity due to MTX is common. It can be acute within the first 24 hours, subacute within a week or can be chronic for months and years. It may manifest as somnolence, confusion, or seizures. Fortunately, it resolves without sequelae with reversal of changes on MRI. MTX can be given as oral, intravenous (IV), intramuscular (IM) or intrathecal (IT).

#pharmacology
#neurology



References:

1. Bhojwani D, Sabin ND, Pei D, et al. Methotrexate-induced neurotoxicity and leukoencephalopathy in childhood acute lymphoblastic leukemia. J Clin Oncol. 2014;32(9):949-959. doi:10.1200/JCO.2013.53.0808


2. Brugnoletti F, Morris EB, Laningham FH, et al. Recurrent intrathecal methotrexate induced neurotoxicity in an adolescent with acute lymphoblastic leukemia: Serial clinical and radiologic findings. Pediatr Blood Cancer. 2009;52(2):293-295. doi:10.1002/pbc.21764

CT vs bronch

Q: 58 year old male with a history of HIV is admitted to ICU with hemoptysis. There is a concern for Kaposi sarcoma. Which study would be appropriate to demonstrate it? (select one)

A) Flexible bronchoscopy
B) High-resolution CT (HRCT)


Answer: A

There is a misconception that HRCT can see everything. Bronchoscopy and CT scan both complement each other. CT scans can demonstrate bronchiectasis, aspergillomas, and carcinomas better. On the other hand, bronchoscopy is ideal for subtle mucosal abnormalities such as bronchitis, papillomas, Dieulafoy disease, bronchial carcinoid, and Kaposi sarcoma.

In the case of active hemoptysis, flexible bronchoscopy would be preferred to visualize active bleeding.

#pulmonary



References:

1. Set PA, Flower CD, Smith IE, et al. Hemoptysis: comparative study of the role of CT and fiberoptic bronchoscopy. Radiology 1993; 189:677. 

2. McGuinness G, Beacher JR, Harkin TJ, et al. Hemoptysis: prospective high-resolution CT/bronchoscopic correlation. Chest 1994; 105:1155. 

3. Tak S, Ahluwalia G, Sharma SK, et al. Haemoptysis in patients with a normal chest radiograph: bronchoscopy-CT correlation. Australas Radiol 1999; 43:451.

EAH

Q: Exercise-associated hyponatremia (EAH) counts for hyponatremia up to what period after exercise? 

A) 24 hours 
B) 48 hours 


Answer: A

The 2015 Third International Exercise-Associated Hyponatremia Consensus Development Conference defined exercise-associated hyponatremia (EAH) as hyponatremia (below the given normal range of laboratory) occurring during up to 24 hours after prolonged physical activity. 

It is more common than anticipated. The most common risk factor is sustained high fluid intake which correlates with weight gain during exercise. Athletes who gain more than 4 percent of their pre-exercise body weight during exercise have an 85 percent probability of developing hyponatremia and a 45 percent probability of developing hyponatremic encephalopathy. 

Contrary to conventional wisdom most of the commercially available carbohydrate/electrolyte-containing sports drink including Gatorade does not provide protection against hyponatremia due to the fact that they all are hypotonic to plasma. Other risk factors include longer race time, a low body mass index, and use of Nonsteroidal anti-inflammatory drugs (NSAIDs).

#electrolytes
#sports-medicine


References: 

 1. Hew-Butler T, Rosner MH, Fowkes-Godek S, et al. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015. Clin J Sport Med 2015; 25:303. 

 2. Dugas J. Sodium ingestion and hyponatraemia: sports drinks do not prevent a fall in serum sodium concentration during exercise. Br J Sports Med 2006; 40:372. 

 3. Baker J, Cotter JD, Gerrard DF, et al. Effects of indomethacin and celecoxib on renal function in athletes. Med Sci Sports Exerc 2005; 37:712.  

4.  Sharwood K, Collins M, Goedecke J, et al. Weight changes, sodium levels, and performance in the South African Ironman Triathlon. Clin J Sport Med 2002; 12:391. 

5. Almond CS, Shin AY, Fortescue EB, et al. Hyponatremia among runners in the Boston Marathon. N Engl J Med 2005; 352:1550. 

LEMS advantage

Q: What makes Lambert-Eaton myasthenic syndrome (LEMS) a disease of advantage?

Answer:  Anytime a patient presents with Lambert-Eaton myasthenic syndrome (LEMS), the first priority should be to look for small cell lung cancer (SCLC) due to a strong association of almost half of the cases. This association becomes more strong with the history of smoking. LEMS usually manifests in the early part of the SCLC and gives an advantage for the more effective treatment for cancer.

 It is also found to be associated with lymphoproliferative disorders though less likely. 

#neurology
#oncology


References:

1. Wirtz PW, Lang B, Graus F, et al. P/Q-type calcium channel antibodies, Lambert-Eaton myasthenic syndrome and survival in small cell lung cancer. J Neuroimmunol 2005; 164:161. 

2. Payne M, Bradbury P, Lang B, et al. Prospective study into the incidence of Lambert Eaton myasthenic syndrome in small cell lung cancer. J Thorac Oncol 2010; 5:34. 

3. Lemal R, Chaleteix C, Minard P, et al. Large granular lymphocytic leukemia associated with Lambert-Eaton Myasthenic Syndrome: A case report. Leuk Res Rep 2013; 2:32. 

4. Siau RT, Morris A, Karoo RO. Surgery results in complete cure of Lambert-Eaton myasthenic syndrome in a patient with metastatic Merkel cell carcinoma. J Plast Reconstr Aesthet Surg 2014; 67:e162. 

5. Nalbantoglu M, Kose L, Uzun N, et al. Lambert-Eaton myasthenic syndrome associated with thymic neuroendocrine carcinoma. Muscle Nerve 2015; 51:936.

Static and Dynamic parameters of fluid responsiveness

Q: What are the static and dynamic parameters of hemodynamic?

Answer: The monitoring of hemodynamic can have two parameters, either static or dynamic. 

Static parameters get measured periodically like cuff Mean Arterial Pressure (MAP), Central Venous Pressure (CVP), and Mixed or Mixed central Venous oxygenation (SVo2 or ScvO2). 

Dynamic parameters include respiratory changes in the vena caval diameter, radial artery pulse pressure, aortic blood flow peak velocity, left ventricular outflow tract velocity-time integral, and brachial artery blood flow velocity. Dynamic parameters are more reliable predictors of fluid responsiveness given a patient is in normal sinus rhythm and passively ventilated. In actively breathing patients or those with irregular cardiac rhythms, a passive leg-raising maneuver is another excellent dynamic parameter to predict fluid responsiveness.

#hemodynamic


References:

1. ARISE Investigators, ANZICS Clinical Trials Group, Peake SL, et al. Goal-directed resuscitation for patients with early septic shock. N Engl J Med 2014; 371:1496. 

2. Michard F, Lopes MR, Auler JO Jr. Pulse pressure variation: beyond the fluid management of patients with shock. Crit Care 2007; 11:131. 

3. Mandeville JC, Colebourn CL. Can transthoracic echocardiography be used to predict fluid responsiveness in the critically ill patient? A systematic review. Crit Care Res Pract 2012; 2012:513480. 

4.  Marik PE, Monnet X, Teboul JL. Hemodynamic parameters to guide fluid therapy. Ann Intensive Care 2011; 1:1.

barotrauma and Pplat

Q: At what level of plateau pressure (Pplat)the chances of barotrauma goes exponentially high while on mechanical ventilator? (select one)

A) Pplat >30 cm H2O 
B) Pplat >35 cm H2O


Answer:  B

The plateau pressure during mechanical ventilation is an excellent representation of pressure applied to the small airways and alveoli. Although barotrauma can occur anytime while on ventilator but risk goes exponentially high with a Pplat >35 cm H2O. Data shows very strong relationship between barotrauma and a Pplat >35 cm H2O. To obtain Pplat, a provider needs to apply a hold on inspiratory breath for 1-2 seconds on the ventilator.

#ventilators
#pulmonary


References:

1. Boussarsar M, Thierry G, Jaber S, et al. Relationship between ventilatory settings and barotrauma in the acute respiratory distress syndrome. Intensive Care Med 2002; 28:406.


2. International consensus conferences in intensive care medicine: Ventilator-associated Lung Injury in ARDS. This official conference report was cosponsored by the American Thoracic Society, The European Society of Intensive Care Medicine, and The Societé de Réanimation de Langue Française, and was approved by the ATS Board of Directors, July 1999. Am J Respir Crit Care Med 1999; 160:2118.

“thoracic endometriosis syndrome”

Q: Hemoptysis can be a part of “thoracic endometriosis syndrome”? (select one)

A) Yes
B) No


Answer: A

Thoracic endometriosis is consistent with endometrial tissue in any part of thorax including pleura, parenchyma, diaphragm, and bronchus. It is usually diagnosed by histological specimens with hormone receptor-positive endometrial stroma and glands from chest tube aspirate, thoracotomy, or bronchoscopy. In case of stroma only or hormone negative tissue, it should be labeled as “probable” thoracic endometriosis. 

When patient presents with clinical symptoms it is called “thoracic endometriosis syndrome”. It may present as single or in combination of pneumothorax, hemothorax, hemoptysis, and chest pain. Usually it occurs during the time of menstruation.

#ob-gyn
#pulmonary


References:

1. Channabasavaiah AD, Joseph JV. Thoracic endometriosis: revisiting the association between clinical presentation and thoracic pathology based on thoracoscopic findings in 110 patients. Medicine (Baltimore) 2010; 89:183. 

2. Korom S, Canyurt H, Missbach A, et al. Catamenial pneumothorax revisited: clinical approach and systematic review of the literature. J Thorac Cardiovasc Surg 2004; 128:502.

3.  Rousset-Jablonski C, Alifano M, Plu-Bureau G, et al. Catamenial pneumothorax and endometriosis-related pneumothorax: clinical features and risk factors. Hum Reprod 2011; 26:2322.

PD-L1

Q: 48 years old male with a history of laryngeal cancer is admitted to ICU for airway monitoring due to stridor and hemoptysis. Oncology service ordered Programmed death-ligand 1 (PD-L1). What is its utility?

Answer: The objective of this question is to introduce ICU care providers with fastly rising immuno-therapy in the oncology field. Cancer patients requiring immunotherapy are now frequently getting admitted to ICU. Programmed death ligand 1 (PD-L1) and its partner PD-L2 is a transmembrane protein expressed in normal tissues to inhibit the activity of T-cells and prevent autoimmunity. PD-L1 is commonly upregulated on the surface of tumor cells, binding to the programmed death 1 (PD-1) expressed on tumor-infiltrating lymphocytes, eventually causing a T-cell tolerance. 

This represents one of the various mechanisms of immune evasion. PD-1 inhibitors (nivolumab and pembrolizumab) exploit this immune escape and are now used for various cancers including head, neck, lungs, and gastroenterology cancers.

#oncology


References: 

Inaguma S, Wang Z, Lasota J, et al. Comprehensive Immunohistochemical Study of Programmed Cell Death Ligand 1 (PD-L1): Analysis in 5536 Cases Revealed Consistent Expression in Trophoblastic Tumors. Am J Surg Pathol. 2016;40(8):1133-1142. doi:10.1097/PAS.0000000000000653

Risks for TRALI

Q: Which organ transplant surgery is found to be a risk factor for Transfusion Related Acute Lung Injury (TRALI)?

A) Liver
B) Lung
C) Kidney
D) Heart

Answer: A

There is a long list of risk factors identified in multiple studies for TRALI. It includes liver transplantation, liver disease, alcohol abuse, mechanical ventilation as well as high peak airway pressure on a ventilator, smoking, positive fluid balance, emergent cardiac surgery, hematologic malignancy, massive transfusion, sepsis, high sickness scores, platelet or plasma-containing products, and female gender.

#hematology
#hepatology
#transplantation


References:

1. Gajic O, Rana R, Winters JL, et al. Transfusion-related acute lung injury in the critically ill: prospective nested case-control study. Am J Respir Crit Care Med 2007; 176:886. 

2. Toy P, Gajic O, Bacchetti P, et al. Transfusion-related acute lung injury: incidence and risk factors. Blood 2012; 119:1757. 

3. Menis M, Anderson SA, Forshee RA, et al. Transfusion-related acute lung injury and potential risk factors among the inpatient US elderly as recorded in Medicare claims data, during 2007 through 2011. Transfusion 2014; 54:2182. 

4. Toy P, Bacchetti P, Grimes B, et al. Recipient clinical risk factors predominate in possible transfusion-related acute lung injury. Transfusion 2015; 55:947.

DKA and PH

Q: During the management of Diabetes Ketoacidosis (DKA), monitoring of which PH is recommended?

A) Arterial
B) Venous


Answer: B 

 In general, the difference between arterial and venous PH is only 0.03 units. If not required there is no need to insert arterial line just for the purpose of DKA management. Venous PH, in general, is adequate to monitor the improvement in DKA. It should be complemented by serum bicarbonate and the serum anion gap from the chemistry. In some institutes bedside ketone meters to measure capillary blood beta-hydroxybutyrate are available which is a good alternative.

#endocrine


References:

1. Middleton P, Kelly AM, Brown J, Robertson M. Agreement between arterial and central venous values for pH, bicarbonate, base excess, and lactate. Emerg Med J 2006; 23:622. 

2. Loh TP, Saw S, Sethi SK. Bedside monitoring of blood ketone for management of diabetic ketoacidosis: proceed with care. Diabet Med 2012; 29:827.

Baux score

Q: What purpose the Baux score serves?

Answer:  Baux score helps to determine the mortality rate in burn patients. In case of a high degree of burn, survival may be unlikely and helps physicians as well as family to decide on further care. 

 Baux score = age + Total Body Surface Area (TBSA) = correlates with mortality 

 There is also a revised Baux score proposed which takes into accounts for the presence of inhalation injury.

Revised Baux score = (TBSA + age + [17×R]). 

R = 1 if patient has inhalation injury, and 
R = 0 if no inhalation injury

Revised Baux score of more than 140-150 corresponds with almost 100 percent mortality 


#burn


References: 

1.  Osler T, Glance LG, Hosmer DW. Simplified estimates of the probability of death after burn injuries: extending and updating the baux score. J Trauma 2010; 68:690. 

2. Roberts G, Lloyd M, Parker M, et al. The Baux score is dead. Long live the Baux score: a 27-year retrospective cohort study of mortality at a regional burns service. J Trauma Acute Care Surg 2012; 72:251.

provoked and unprovoked DVT

Q: Deep venous thrombosis (DVT) after hospitalization is considered? (select one)

A) provoked DVT
B) unprovoked DVT


Answer: A

To simplify and stratify the treatment of DVT, nomenclatures have been designated to DVTs. It includes provoked, unprovoked, symptomatic, asymptomatic, proximal, or distal. 

Describing indications of treatment in each category is beyond the scope of this site but the objective of this question is to highlight the fallacy of common practice in ICU or hospitals to call incidental findings in hospitalized patients as unprovoked DVT. Hospitalization, surgery, pregnancy, malignancy, estrogen treatment, CHF, inflammatory bowel diseases are some examples of provoked DVT.

#hematology
#nomenclature


Reference:

1. Kearon C, Ageno W, Cannegieter SC, Cosmi B, Geersing GJ, Kyrle PA; Subcommittees on Control of Anticoagulation, and Predictive and Diagnostic Variables in Thrombotic Disease. Categorization of patients as having provoked or unprovoked venous thromboembolism: guidance from the SSC of ISTH.J Thromb Haemost. 2016; 14:1480–1483. doi: 10.1111/jth.13336

2. Tritschler T, Wells PS. Extended therapy for unprovoked venous thromboembolism: when is it indicated?. Blood Adv. 2019;3(3):499. doi:10.1182/bloodadvances.2018026518

Bent at ETI

Q: What is the purpose of the bent at the tip of the endotracheal tube introducer (ETI)?

Answer:  The endotracheal tube introducer (ETI), popularly known as bougie is frequently used during difficult intubation where vocal cords are not visible (Grade 3 view). The tip of the ETI is usually bent at the distal tip at a 30-degree angle. This purposefully applied bent servers two purposes. It allows an operator to direct the tip anteriorly under the epiglottis and through the vocal cords. Secondly, the bent helps an operator to feel and produce palpable "clicks" when advancing into the trachea. This is a pretty indicator of successful intubation.

Youtube video @ https://youtu.be/E7Lo1JD2Brk


#procedures


References:

1. Kidd JF, Dyson A, Latto IP. Successful difficult intubation. Use of the gum elastic bougie. Anaesthesia 1988; 43:437. 

2. Driver BE, Prekker ME, Klein LR, et al. Effect of Use of a Bougie vs Endotracheal Tube and Stylet on First-Attempt Intubation Success Among Patients With Difficult Airways Undergoing Emergency Intubation: A Randomized Clinical Trial. JAMA 2018; 319:2179.

Organism in septic arthritis

Q: Septic arthritis is usually? (select one)

A) Monomicrobial
B) Polymicrobial



Answer: A

In non-immunocompromised and with no history of trauma septic arthritis is usually monomicrobial secondary to staphylococcus aureus. Septic arthritis due to streptococcus pneumoniae is also possible though less likely. Immunocompromised, older, and intravenous (IV) drug abusers may get gram-negative bacilli mono septic arthritis. 

Polymicrobial septic arthritis is seen in either penetrating trauma or polymicrobial bacteremia. Septic arthritis in smaller joints is more tend to be polymicrobial.

#infectious-diseases


References:

1. McBride S, Mowbray J, Caughey W, et al. Epidemiology, Management, and Outcomes of Large and Small Native Joint Septic Arthritis in Adults. Clin Infect Dis 2020; 70:271. 

2. Mathews CJ, Coakley G. Septic arthritis: current diagnostic and therapeutic algorithm. Curr Opin Rheumatol 2008; 20:457.

3. Frazee BW, Fee C, Lambert L. How common is MRSA in adult septic arthritis? Ann Emerg Med 2009; 54:695. 

4. Nelson GE, Pondo T, Toews KA, et al. Epidemiology of Invasive Group A Streptococcal Infections in the United States, 2005-2012. Clin Infect Dis 2016; 63:478. 

5. Ross JJ, Saltzman CL, Carling P, Shapiro DS. Pneumococcal septic arthritis: review of 190 cases. Clin Infect Dis 2003; 36:319. 

6. Allison DC, Holtom PD, Patzakis MJ, Zalavras CG. Microbiology of bone and joint infections in injecting drug abusers. Clin Orthop Relat Res 2010; 468:2107.

A-a gradient

Q: With higher FiO2, the A-a gradient will? (select one)

A) increase
B) decrease


Answer: A

The Alveolar–arterial gradient, popularly known as A–a gradient is simply a measure of the difference between the alveolar concentration (A) of oxygen and the arterial (a) concentration of oxygen. A normal A–a gradient is usually around 10 mmHg, and need to be adjusted for the age. Logic may imply that if a patient is breathing a very high FiO2, PaO2 will go up and A-a gradient will decrease. In actuality, when a patient receives a very high FiO2, both PAO2 and PaO2 increase, but the PAO2 increases disproportionately. This results in A-a gradient to increase.

In a clinical situation of hypoxemia, P/F (Po2/FiO2) ratio is a better determinant of hypoxemia

#pulmonary




Reference:

Kanber GJ, King FW, Eshchar YR, Sharp JT. The alveolar-arterial oxygen gradient in young and elderly men during air and oxygen breathing. Am Rev Respir Dis 1968; 97:376.

spinal schwannomatosis

Q: 42 year old female is admitted to ICU with progressive weakness of both upper extremities with motor function deficits. Weakness is associated with pain. MRI was performed in the emergency department (ED) showing schwannoma at cervical level causing spinal cord compression. Neurosurgery service decides to pursue surgery. The patient inquired regarding her chances of recovery? (select one)

A) Full recovery
B) no recovery of lost function


Answer: B

When schwannoma is associated with clinical symptoms it is called schwannomatosis. In normal cases, surgery is usually avoided due to its benign nature. Pharmacologic and non-pharmacologic interventions are treatments. In life-threatening situations like our patient in the above question, surgery is indicated. This is unfortunate that in schwannomas lost neurological functions do not get recovered despite its benign pathology and removal of the mass. Surgery helps in preventing the progression of the disease i.e., loss of neuro function. Another grim part of this scenario is that may help in the resolution of pain but may also paradoxically exacerbate the pain.

#neuro-surgery
#surgical-critical-care


Reference:

1. Jacopo Lenzi, et al. Spinal Nerves Schwannomas: Experience on 367 Cases—Historic Overview on How Clinical, Radiological, and Surgical Practices Have Changed over a Course of 60 Years Neurology Research International. Volume 2017 |Article ID 3568359 | 12 pages | https://doi.org/10.1155/2017/3568359

2. T. Jinnai, M. Hoshimaru, and T. Koyama, “Clinical characteristics of spinal nerve sheath tumors: analysis of 149 cases,” Neurosurgery, vol. 56, no. 3, pp. 510–515, 2005. 

3. M. T. Seppala, M. J. J. Haltia, R. J. Sankila, J. E. Jaaskelainen, and O. Heiskanen, “Long-term outcome after removal of spinal schwannoma: a clinicopathological study of 187 cases,” Journal of Neurosurgery, vol. 83, no. 4, pp. 621–626, 1995. 

4. P. Li, F. Zhao, J. Zhang et al., “Clinical features of spinal schwannomas in 65 patients with schwannomatosis compared with 831 with solitary schwannomas and 102 with neurofibromatosis type 2: a retrospective study at a single institution,” Journal of Neurosurgery Spine, vol. 24, no. 1, pp. 145–154, 2016.

A note on LAST

A note on Local anesthetic systemic toxicity (LAST) 

Topical lidocaine is frequently used in ICU for various procedures. The risk of toxicity is higher if it is applied to mucosal membranes, particularly either repeatedly or in high doses. This could be a classic situation after prolonged bronchoscopy. In such situations, they could be either absorbed through mucous membranes or swallowed via the gastrointestinal (GI) tract. It can also be absorbed after applying to the skin. It may lead to neuro or cardio toxicities manifesting as seizures, arrhythmia, or cardiac arrest.

#procedures
#pharmacology


References:

1. Labedzki L, Ochs HR, Abernethy DR, Greenblatt DJ. Potentially toxic serum lidocaine concentrations following spray anesthesia for bronchoscopy. Klin Wochenschr 1983; 61:379. 

2. Nath MP, Baruah R, Choudhury D, Chakrabarty A. Lignocaine toxicity after anterior nasal packing. Indian J Anaesth 2011; 55:427. 

3. Horáček M, Vymazal T. Lidocaine not so innocent: Cardiotoxicity after topical anaesthesia for bronchoscopy. Indian J Anaesth 2012; 56:95. 

4. Oni G, Brown S, Burrus C, et al. Effect of 4% topical lidocaine applied to the face on the serum levels of lidocaine and its metabolite, monoethylglycinexylidide. Aesthet Surg J 2010; 30:853.