Amiodarone induced thyroid problems

Q: Amiodarone causes thyroid problems because?

A) It resembles thyroxine

B) It contains high amount of Iodine

C) Both A and B

D) It blocks potassium channels

E) It is idiopathic (cause unknown)

Answer: C

Amiodarone chemically resembles thyroxine, and it binds to the nuclear thyroid receptor which contributes to its toxic effect on thyroid, either amiodarone-induced thyrotoxicosis (AIT) or amiodarone-induced hypothyroidism (AIH). Also, iodine in Amiodarone play significant role in pathology.

There are two main forms of AIT: type 1, a form of iodine-induced hyperthyroidism, and type 2, a drug-induced destructive thyroiditis. However, mixed/indefinite forms also exists.

The most likely mechanism of AIH is an enhanced susceptibility to the inhibitory effect of iodine on thyroid hormone synthesis

Q: How is "Reverse use dependence" is defined for any cardiac drug?

Answer: Reverse use dependence is defined as an inverse correlation between the heart rate and the QT interval. As a result, the QT interval is prolonged as the heart rate slows, with an associated risk of drug-induced torsades de pointes -  and a possible decrease in drug efficacy at higher heart rates. This is very co-related with sotalol and other class III antiarrhythmic drugs, except for amiodarone. 

Q: Which of the following may cause SIADH

A) Amiodarone

B) Empyema

C) Pneumothorax

D) Positive pressure ventilation

E) All of the above

Answer: E

SIADH has a long list of causes but from ICU perspective above ones are important to be of aware of. Other causes are Asthma, Bronchiectasis, Lung abscess, pneumonia, Brain abscess, Cerebral tumor, Head trauma, Psychosis, Stroke, Subdural hematoma, Bronchogenic carcinoma, Pancreatic cancer, Mesothelioma, Small-cell lung carcinoma, SSRI, Theophylline and others.

Q: For acalculous cholecystitis all of the following are part of treatment except ?

A)  open or laparoscopic cholecystectomy

B) endoscopic gallbladder stent placement

C)  antibiotics

D) percutaneous cholecystostomy

E) Observation

Answer: E

Acalculous cholecystitis requires immediate intervention due to high risk of gallbladder perforation.

In stable patients open or laparoscopic cholecystectomy is preferred. In non-surgical patients, endoscopic gallbladder stent placement of a double pigtail stent between the gallbladder and the duodenum via ERCP can be effective. Other option in non-operable patients is antibiotics with percutaneous cholecystostomy. If patient is unstable for any procedure, at least antibiotics should be given.

Q: Nasoenteric tubes tend to be blocked frequently because they are usually longer and of finer bore. They are susceptible to being obstructed by crushed medications, viscous feeds or stasis. In the event of clogging, a tube can usually be unblocked by flushing with?

A)  hot water

B) coca-cola

C) pancreatic enzymes

D) All of the above

Answer: D

Nasoenteric tubes tend to be blocked because they are usually longer and of finer bore. They are especially susceptible to being obstructed by crushed medications, viscous feeds and inadequate flushing. Therefore, these tubes should be flushed every 4-6 h, always before and after usage, and dense feeds and medications should be avoided. In the event of clogging, a tube can usually be unblocked by flushing it with hot water, coca-cola or pancreatic enzymes

Reference:

Niv, E., Fireman, Z., & Vaisman, N. (2009). Post-pyloric feeding. World Journal of Gastroenterology : WJG, 15(11), 1281–1288. doi:10.3748/wjg.15.1281

Q: 32 year old male with history of ETOH abuse is admitted to ICU with acute upper GI bleed secondary to varices. How long patient can be left NPO or parenteral nutrition?

Answer: About 4 days.

Primary goal in Upper GI bleed secondary to varices it to stabilize the hemodynamics, avoiding extra resuscitation and minimize the risk of re-bleeding. Early parenteral nutrition (TPN) may lead to hypervolumeia and increase portal pressure. Patient may go up to 4 days without any nutrition.

Reference:

de Lédinghen V, Beau P, Mannant PR, et al. (1997). "Early feeding or enteral nutrition in patients with cirrhosis after bleeding from esophageal varices? A randomized controlled study". Dig. Dis. Sci. 42 (3): 536–41.

Q: How Roth's spot is best defined?

Answer: Pale-centered hemorrhage.

Major causes of Roth's spot are

• bacterial endocarditis
• pernicious anemia,
• ischemic events,
• hypertensive retinopathy
•  HIV retinopathy
•  leukemia
• diabetes

Q: Bones of the skull block the transmission of ultrasound, than how transcranial doppler is performed?

Answer: Transcranial doppler uses insonation windows. Insonation windows are regions in skull with thinner walls. Recording is performed in the temporal region above the cheekbone/zygomatic arch, through the eyes, below the jaw, and from the back of the head. Various factors affect bone thickness, and may make some examinations difficult or even impossible. 

Q: You have been called to evaluate a 44 year old male in ER for acute CVA. Patient is still within time limit of thrombolytic therapy and t-PA is ordered. Which one added therapy may help as an adjuvant treatment?

Answer: Cranial doppler

By delivering mechanical pressure waves to the thrombus, ultrasound can theoretically expose more of the thrombus’s surface to the circulating fibrinolytic agent. It is not a standard of treatment but may help in young patients. Neurology team should be consulted.

Reference:

Alexandrov AV, Molina CA, Grotta JC, Garami Z, Ford SR, Alvarez-Sabin J, et al. Ultrasound-enhanced systemic thrombolysis for acute ischemic stroke. N Engl J Med. Nov 18 2004;351(21):2170-8.

Tsivgoulis G, Eggers J, Ribo M, Perren F, Saqqur M, Rubiera M, et al. Safety and efficacy of ultrasound-enhanced thrombolysis: a comprehensive review and meta-analysis of randomized and nonrandomized studies. Stroke. Feb 2010;41(2):280-7.

Q: 54 year old male is admitted via ER to ICU with hypertensive crisis. ER physician chose to use IV Fenoldopam in view of patient's baseline renal insufficiency with creatinine of 2.5. Patient showed partial response to Fenoldopam. You decided to add Esmolol as second anti-hypertensive. After 15 minutes of addition and titration of Esmolol, patient acutely became hypotensive and coded. What could be the explanation?

Answer: Fenoldopam does not only have a selective D1 receptor agonist effect but also have some alpha-1 and alpha-2 adrenoceptor antagonist activity. It may cause sympathetic-mediated reflex tachycardia and concomitant use of beta-blocker should be avoided, as unexpected hypotension can result from beta-blocker inhibition of tachycardia.

Q: What is the life saving measure in thyroid storm when all conventional treatments fail?

Answer: Plasmapheresis

Plasmapheresis causes removal of cytokines, putative antibodies, and thyroid hormones and their bound proteins. Few pearls to remember

• Though plasmapheresis is the fastest method for the improvement of the thyroid storm, it has a transitory effect and thus should be associated with other thyroid blockers.
• In anticipated life threatening situation, plasmapheresis should be done early without waiting for the efficiency of conventional treatment.
• In cases involving neurologic symptoms, plasmapheresis should be high on list for treatment.

Petry J, Van Schil PE, Abrams P, Jorens PG. Plasmapheresis as effective treatment for thyrotoxic storm after sleeve pneumonectomy. Ann Thorac Surg. May 2004;77(5):1839-41.

Q: Name 5 very common complications of plasmapheresis, which usually require intervention in ICU?

Answer:

• Hypocalcemia
• Hypomagnesemia
• Hypothermia
• Hypotension
• Hypofibrinogenemia*

* (in particular if using albumin as a replacement product) 

Reference:  

Mokrzycki MH, Kaplan AA. Therapeutic plasma exchange: complications and management. Am J Kidney Dis. Jun 1994;23(6):817-27.

Q: What percentage of patients develop post-extubation laryngeal edema?

Answer: Surprisingly, clinically relevant post-extubation laryngeal edema occurs in up to 30% of extubated patients, but only 4% of patients need to be reintubated due to laryngeal edema.

Reference:

Bastiaan HJ Wittekamp, Walther NKA van Mook, Dave HT Tjan, Jan Harm Zwaveling and Dennis CJJ Bergmans -  Clinical review: Post-extubation laryngeal edema and extubation failure in critically ill adult patients - Critical Care 2009, 13:233 

Diclofenac suppository in early post-operative relief of pain and shivering in spinal anesthesia?

Background: Pain and shivering are two challenging components in the post operative period. Many drugs were used for prevention and treatment of them. The aim of this study was to compare the effects of prophylactic prescription of diclofenac suppository versus intravenous (IV) pethidine in spinal anesthesia.

Materials and Methods: We conducted a multi central, prospective, double-blind, randomized clinical trial on a total of 180 patients who were scheduled for surgery under spinal anesthesia including 60 patients in three groups. Patients were randomly allocated to receive 100 mg sodium diclofenac suppository or 30 mg IV pethidine or placebo. Categorical and continuous variables were analyzed by Chi-square test, t-test, Mann-Whitney and ANOVA or Kruskal-Wallis tests.

Results: There was no statistical difference with regard to patient characteristics and hemodynamic indices among the three groups. Nine (15%), 10 (16.65%) and 24 (40%) of patients in diclofenac, pethidine and control groups reported pain and 2, 2, 7 patients received treatment due to it, respectively (P = 0.01). Prevalence of shivering in pethidine group and diclofenac group was the same and both of them were different from the control group (P < 0.001). Pruritus was repetitive in the pethidine group and was statistically significant (P = 0.036) but, post-operative nausea and vomiting was not significantly different among groups.

Conclusion: A single dose of sodium diclofenac suppository can provide satisfactory analgesia immediately after surgery and decrease shivering without remarkable complications. This investigation highlights the role of pre-operative administration of a single dose of rectal diclofenac as a sole analgesic for early post-operative period.

Reference:

Ebrahim AJ, Mozaffar R, Nadia Bh, Ali J. Early post-operative relief of pain and shivering using diclofenac suppository versus intravenous pethidine in spinal anesthesia. J Anaesthesiol Clin Pharmacol 2014;30:243-7

Preventing Fires in the Operating Room

Foley catheters--is infection the greatest risk?

PURPOSE: Foley catheters cause a variety of harms, including infection, pain and trauma. Although symptomatic urinary tract infection and asymptomatic bacteriuria are frequently discussed, genitourinary trauma receives comparatively little attention.

 MATERIALS AND METHODS: A dedicated Foley catheter nurse prospectively reviewed the medical records of inpatients with a Foley catheter at the Minneapolis Veterans Affairs Medical Center from August 21, 2008 to December 31, 2009. Daily surveillance included Foley catheter related bacteriuria and trauma. Data were analyzed as the number of event days per 100 Foley catheter 

 RESULTS: During 6,513 surveyed Foley catheter days, urinalysis/urine culture was done on 407 (6.3%) days. This testing identified 116 possible urinary tract infection episodes (1.8% of Foley catheter days), of which only 21 (18%) involved clinical manifestations. However, the remaining 95 asymptomatic bacteriuria episodes accounted for 39 (70%) of 56 antimicrobial treated possible urinary tract infection episodes (for proportion of treated episodes with vs without symptomatic urinary tract infection manifestations, p = 0.005). Concurrently 100 instances of catheter associated genitourinary trauma (1.5% of Foley catheter days) were recorded, of which 32 (32%) led to interventions such as prolonged catheterization or cystoscopy. Trauma prompting an intervention accounted for as great a proportion of Foley catheter days (0.5%) as did symptomatic urinary tract infection (0.3%) (p = 0.17) 

 CONCLUSIONS: In this prospective surveillance project, intervention triggering Foley catheter related genitourinary trauma was as common as symptomatic urinary tract infection. Moreover, despite recent increased attention to the distinction between asymptomatic bacteriuria and symptomatic urinary tract infection in catheterized patients, asymptomatic bacteriuria accounted for significantly more antimicrobial treatment than did symptomatic urinary tract infection. Elimination of unnecessary Foley catheter use could prevent symptomatic urinary tract infection, unnecessary antimicrobial therapy for asymptomatic bacteriuria and Foley catheter related trauma.

Reference:

Leuck AM, Wright D, Ellingson L, Kraemer L, Kuskowski MA, Johnson JR - Complications of Foley catheters--is infection the greatest risk?J Urol. 2012 May;187(5):1662-6.

Q: Which one simple step before paracentesis may be helpful?

Answer:   Emptying of bladder.

Emptying of bladder, either by patient himself or by insertion of foley catheter reduce the chances of complication. Preferably, ultrasound should be used to guide insertion of needle in Paracentesis.

Q: 48 year old male with previous history of seizure is in ICU after community acquired pneumonia. Patient missed his regular anti-seizure meds for 2 days. Patient has episode of seizure in ICU. After resolution of seizure, patient is noticed to develop right sided weakness. CT scan is negative. Patient anti-seizure meds are restarted. What is the next step?

A) Start Heparin

B) Start Plavix

C) Insert ICP monitoring device

D) Observation

E) Induce pentobarbital coma

Answer:   D

Patient has most probably developed Todd's Paralysis which is common after seizure. Usually it resolve within 48 hours. Todd's paralysis is a focal weakness  and is usually localized to either the left or right side of the body. Rarely, it affects speech, gaze or vision.

With resolution of seizure, negative CT scan and clear history of missed anti-seizure meds, there is no need at this point for heparin, Plavix, pentobarbital or insertion of ICP device.

Q: Which lab test best describe to suspect pseudohyperkalemia

A) platelets (>500,000/mm³), leukocytes (> 50 000/mm³), or erythrocytes (hematocrit > 55%)

B) platelets (>300,000/mm³), leukocytes (> 70 000/mm³), or erythrocytes (hematocrit > 55%)

C) platelets (>500,000/mm³), leukocytes (> 70 000/mm³), or erythrocytes (hematocrit > 55%)

D) platelets (>500,000/mm³), leukocytes (> 70 000/mm³), or erythrocytes (hematocrit > 48%)

E) platelets (>300,000/mm³), leukocytes (> 40 000/mm³), or erythrocytes (hematocrit > 45%)

 

Answer:   C

Some of the common reasons of Pseudohyperkalemia are

• hemolysis during venipuncture
• a delay in the processing of the specimen. 
• Thrombocytosis (>500,000/mm³)
• Leukocytosis (> 70 000/mm³)
• Erythrocytosis (hematocrit > 55%)

Q: Cyanide poisoning is consistent with which kind of Odor?

A) Bitter almonds

B) Burnt rope

C) Garlic

D) Mint

Answer:   A (Odor of bitter Almond)

Almost half of patients exposed to cyanide described odor of bitter almonds.

Burnt rope smell is consistent with marijuana toxicity. Garlic with organophosphate and Mint with methanol toxicity.

Q: At what PH Metabolic Alkalosis should be viewed as concern and treatment should be sought

A) 7.45

B) 7.50

C) 7.55

D) 7.6

E) 7.7

Answer:    C

Unfortunately, in ICU metabolic alkalosis does not enjoy as much respect as metabolic acidosis, At least one study, which is now about 28 years old, looked directly into morbidity and mortality related to severity of metabolic alkalosis. The mortality associated with severe metabolic alkalosis was around 45% in patients with an arterial blood pH of 7.55 and 80% when the pH was greater than 7.65. 

Reference:

Anderson LE, Henrich WL: Alkalemia-associated morbidity and mortality in medical and surgical patients. South Med J 80 : 729-733, 1987

Q: Lactate Ringer (LR) is an alkalizing solution. Its PH is

A) 7.4

B) 8

C) 7.8

D) 6.5

E) 5

Answer: D

Interestingly, although LR is an alkalizing solution, its an acidic solution with pH of 6.5. The lactate is metabolized into bicarbonate by the liver, which can help correct metabolic acidosis. Though lactate itself contributes a strong anion and generates protons, Ringers Lactate solution alkalinizes via the sodium cations it leaves behind. They increase the strong ion difference in solution, leading to proton consumption and an overall alkalinizing effect.

Q: What does "bolus" means (like in IVF bolus)?

Answer: Bolus is a Latin word, which means ball

It is used in medicine to signify an effort of raising level of something very aggressively, like IVF bolus or bolus of some drug.

Q: Eptifibatide, glycoprotein IIb/IIIa inhibitor, which is frequently used in acute coronary syndrome and during PCI (percutaneous coronary intervention) is contraindicated in which population of patients?

Answer: Hemodialysis (HD) dependent patients

Safety of eptifibatide is not established in HD patients and so should be use with extreme caution, if absolutely necessary.

Patients who have creatinine clearance <50 mL/min, the recommended dose is an intravenous bolus of 180 µg/kg, immediately followed by a continuous infusion of 1.0 µg/kg/min, which is half of normal infusion dose. Second IV bolus of 180 µg/kg is usually given after 10 minutes of first bolus.

Q: Is penile implant contraindicated for MRI?

Answer: Not always, but caution is advised.

Penile implant is unlikely to severely injure a patient undergoing an MRI but it can be very uncomfortable for a patient in case of some brands of ferromagnetic penile implants. Radiology should be notified with specific brand of penile implant.

Reference:

Lowe G, et al. A catalog of magnetic resonance imaging compatibility of penile prostheses. J Sex Med. 2012;9:1482-1487

Q: What is splenic rub?

Answer: In suspected splenomegaly beside palpation and percussion, the left upper quadrant should be auscultated during inspiration.  The left upper quadrant and left lower ribs anteriorly and laterally should be auscultated. Splenic rub is a coarse, scratching sound coincident with inspiration.

Q: Why cardiac workup is essential during diagnosis and management of Myxedema coma?

Answer: Cardiac workup, particularly ruling out myocardial infarction (MI) and cardiac ischemia, is essential during diagnosis and management of Myxedema coma for 2 reasons

1. It is not uncommon for myocardial ischemia/infarction to be  a precipitant of myxedema coma/crisis

2. Full-dose T4 therapy may worsen myocardial ischemia by increasing myocardial oxygen demand.