Saturday, May 8, 2021

Creatinine clearance in elderly - basic notes


Elderly people have a decrease in creatinine clearance (CrCl), which means an increase in serum Cr. It is observed that annual rate of this decrease in CrCl is approximately 1 ml/min. after the age of 50 years.

Therefore, it is important to calculate the dose and dosing intervals of nephrotoxic drugs (eg., aminoglycosides) in these patients in order to prevent the precipitation of ARF.

In general,

CrCl <100 ml/min is abnormal.

However, CrCl <10 ml/min signifies the onset and worsening of acute renal failure.

Note -

• GFR is directly proportional to CrCl.

• GFR decreases by age, but not always accompanied by rise in Cr.

• Cockcroft-Gault formula is commonly referred to for calculating CrCl.

CrCl = (Ucr × V)/Pcr (~GFR)

• Double the Cr = Half the GFR.

Note that those patients with signs of worsening diabetes and resulting glomerulopathies, an increase in both GFR and CrCl is seen, which thus causes hyper filtration injury. 

That's all

- Jaskunwar Singh

Rigler's triad mnemonic


Rigler's triad in gall stone ileus mnemonic:


Belimumab mnemonic

What is belimumab?

Belimumab is a  monoclonal antibody directed against soluble B lymphocyte stimulator (BLyS).

Belimumab is used in the treatment of? 
Systemic Lupus Erythematosus (SLE)

Mnemonic: Belly Selly SLE (rhymes! sing it enough times and you will never forget)

At present, belimumab is indicated as add-on therapy in adults with active, antinuclear antibody or anti-dsDNA-positive SLE with a high degree of disease activity in the skin and/or musculoskeletal systems that remain moderately to severely active despite optimized standard immunosuppression. 

Patients with severe lupus nephritis or active CNS lupus are not the candidates for belimumab.

That's all!

Direct oral anticoagulants (DOACs) dosing for stroke prevention in atrial fibrillation mnemonic

Hi everyone!

Here are some DOAC dosing mnemonics for atrial fibrillation! 

RivarOxaban: Once daily
Apixaban: Twice daily 
Dabigatran: Twice daily
EdOxaban: Once daily

Mnemonic: Drugs with O have Once-daily dosing. 

Rivaroxaban: 20 mg once daily with the evening meal (creatinine clearance [CrCl] >50 mL/minute); or 15 mg once daily with the evening meal (CrCl ≤50 mL/minute).
Mnemonic: R without the straight line | looks like 2 to me for 20 mg!

Apixaban: 5 mg twice daily (CrCl >50 mL/minute); or 2.5 mg twice daily for those with any two of the following: age ≥80 years, body weight ≤60 kg, or serum creatinine ≥1.5 mg/dL.
Mnemonic: Apixa has 5 letters for 5 mg!

Dabigatran: 110 mg BID or 150 mg BID (CrCl >30 mL/minute).
European labeling suggests dose reduction in patients older than 75 years (eg, 150 mg orally once per day or 110 mg orally twice per day).

Edoxaban: 30 mg (weight ≤60 kg) or 60 mg (weight >60 kg) orally once daily.

That's all!

Remember that the dosing varies for VTE treatment and prophylaxis so do not apply these mnemonics for VTE.


Friday, May 7, 2021

Formulation, absorption and associated side effect of dabigatran

Did you know that the absorption of dabigatran etexilate is dependent on an acid environment in the stomach?

This is why it is formulated together with tartaric acid pellets. These pellets provide an acidic environment, which increases drug dissolution and absorption, regardless of variations in gastric pH. This is also why the absorption is not affected by the coadministration of a proton pump inhibitor.

A lower pH is associated with dyspepsia, esophagitis, and plays a part in the increased risk of gastrointestinal bleeding.


Simvastatin combination with fibrates in clinical practice


High-yield in clinical practice:

DO NOT combine simvastatin with gemfibrozil (class-X interaction; high risk of acute liver damage and rhabdomyolysis). Inhibition of CYP450 enzyme by gemfibrozil plays the role in increasing levels of simvastatin 2-3x.

Combination of simvastatin with fenofibrate is relatively safer, although close observation and regular monitoring is required (class-C interaction). Serum levels of simvastatin remain unchanged.

- Jaskunwar Singh

Thursday, May 6, 2021

Mechanical Ventilation- Physiology

Mechanical Ventilation- Physiology

  • Non-Invasive Ventilation is of two types:

  1. CPAP = Continuous Positive Airway Pressure: where continuous pressure is exerted during inspiration and expiration 

  2. BiPAP = Bilevel Positive Airway Pressure: where higher pressures are applied during inspiration and lower pressures during expiration

  • Use of CPAP 🡪increases intra-thoracic pressure 🡪 decreases Venous Return (VR) 🡪 decreased Right Ventricular (RV) preload.

  • PEEP > CVP 🡪 Preload decreases

  • PEEP > PAP 🡪 Afterload decreases (where PEEP = Positive end expiratory pressure, CVP = Central venous Pressure, PAP = Pulmonary arterial pressure)

  • Cardiac Transmural Pressure = pressure difference between inside of the heart and intrathoracic pressure. When CPAP is given, intrathoracic pressure increases 🡪 transmural pressure decreases 🡪Afterload decreases

  • CPAP: Increases inspiratory flow 🡪 Increases Tidal Volume (TV) 🡪 helps in unloading the inspiratory muscles to decrease work of breathing 🡪decrease dyspnea

  • Increase in expiratory pressure (like with CPAP) in patients with COPD helps in increasing ventilation and oxygenation. This might seem contradictory (how does increased pressure from the ventilator into the lungs during expiration help in increasing ventilation. It seems counter intuitive!). In order to understand this, think about how PURSED LIP breathing in COPD patients actually help them to breathe better!

  • COPD patients need an additional external PEEP in addition to inspiratory support to improve diaphragmatic function.

  • PRE-OXYGENATION: with 100% O2 for at least 3 minutes helps to prolong the apnea time (Apnea time = time to reach 88 to 90% SpO2). The FRC (functional residual capacity) is the reservoir during the period of apnea. 


  1. Moderate inflation: pulmonary stretch receptors reduce vagal stimulation 🡪 moderate tachycardia

  2. Hyperinflation: Stimulates Pulmonary C and J receptors 🡪 increased vagal signaling 🡪 bradycardia

    - Low Tidal Volume
    - High PEEP (to keep lungs open, prevent alveolar collapse)
    - Low plateau Pressure

  • Esophageal Balloon: Can help in measuring pressures to deliver adequate PEEP and TV.

    -Auto PEEP is the difference between alveolar pressure and the pressure at the proximal airway.
    -At the exact end of expiration, ideally, we expect the pressure in the alveoli to be zero as all air should have exited from the alveoli. But when some gas is retained, it leads to the development of Auto PEEP.
    -Auto PEEP is measured by end expiratory hold maneuverer.
    -If elastic forces are high and resistive forces (eg resistance in bronchi etc) are low, auto PEEP is minimal or absent.
    -Increase in resistive forces 🡪 passive exhalation time increases to ensure complete emptying of expiratory tidal volume.

    -Time required for lungs to expire 63% of initial volume during expiration.
    -So total of 3 time constants would be needed to exhale 96% of TV out.
    -So, if we keep Inspiratory: Expiratory time as 1:3, Auto PEEP would not occur.
    -Diseases lung is inhomogeneous and can have different time constants for different parts 🡪 Expiratory flow limitation.
    -Flow limitation = dynamic condition that occurs when gas flow cannot be increased by increasing alveolar pressure or reducing airway opening pressure.

  • Dynamic hyperinflation is not the same as air trapping
    -In Asthma, inspiratory activity continues into early expiration 🡪 dynamic hyperinflation, without air trapping
    -In Recumbent obese patients, air trapping occurs without dynamic hyperinflation.

    -Increased risk of infection as compared to Endotracheal Tube (ET) because:
    1. Lack of humidification
    2. Absence of cough, hence decreased clearance of secretions
    3. Reduced ciliary function
    -Reduced work of breathing as compared to ET because:
    Tracheostomy tubes are smaller, more rigid 🡪 less turbulent airflow 🡪 reduces expiratory flow limitation, dynamic hyperinflation, auto-PEEP 🡪 reducing work of breathing

Written by Amrin Kharawala

Saturday, May 1, 2021

Lyme's disease - a review


Lyme's disease/ Lyme borreliosis

A patient with a typical history of frequent visits to the woods with bull's eye rash, neurologic features, cardiac abnormalities, and musculoskeletal features.

Tuesday, April 27, 2021


REQUIREMENTS: Written Informed Consent, Sterile gauze pieces, Saline, Sterile working surface (A plastic drape is generally spread over the table), Syringe with local anaesthesia, Scalpel with 15 no. blade with toothed forceps   (or a sharp curette), Sterile gauze pieces and dressing

1)    Local anesthesia (may not be required for diabetic ulcer as it is painless)

2)    Use saline/ antiseptic solution to irrigate the wound (betadine solution is better avoided as it hampers wound healing)

3)    Using all aseptic precautions remove the dead tissue using 15 no. blade and toothed forceps

4)    Use short even strokes with minimal pressure (swapping movements) to avoid injury to underlying structures and minimize any bleeding that might occur.

-All devitalized tissue must be excised until bleeding occurs

-Muscle that is pale or dark in colour, does not contract on pinching and does not bleed on cutting must be removed

-Try to scrape superficially at the edge of ulcer as this is where the healthy tissue grows

5)    The wound is covered up with either wet or dry dressing

6)    Advice to patient: 

No weight bearing on the wound

Reassess and dress as required

Tetanus immunization and antibiotics as indicated

Written by our guest author Pratik Mundada

Lone Atrial fibrillation mnemonic

 "lone AF"

Mnemonic - "P- LONE"

  • Paroxysmal & Persistent or Permanent 

  • Less than 60 years of age 
  • Low  risk of systemic embolization

  • have a CHA2DS2-VASc score of 0


  • No evidence of cardiopulmonary or structural heart disease.   
  • No anticoagulant therapy is not indicated.

  • Keep an Eye on it , no additional treatment is required.
Thank you!

Monday, April 26, 2021

Menkes disease and Wilson's disease - DDx


Okay so maybe they are the two of the options for a patient's clinical scenario question and you have a blurred memory for which is which in context to copper metabolism?

Let's clear the basic facts here...

Saturday, April 24, 2021

Ampicillin-rash in infectious mononucleosis!


Penicillins such as amoxicillin and ampicillin are currently not recommended in patients with infectious mononucleosis with bacterial secondaries (streptococcal tonsillo-pharyngitis). Why?

Wednesday, April 21, 2021

The Indian Intern

Hi! 🤠
While doing procedures as interns, it is difficult to look for concise sources to know how-best-to-do-it.
With the time constraints some details may be missed.

So, we, students of 2016 batch Seth GSMC and KEM Hospital, Mumbai, India have tried to compile information regarding such procedures (both basic and some that we may get a chance to perform).
Reliable sources and tips from our seniors and resident doctors have been used.

With limited resources in India, we can definitely do with a Freakshake🥤 of practical hacks and standard procedures😉🙃

PS: This is meant to COMPLEMENT, and not REPLACE practical skills to improve patient care

From continued efforts of 

Anveshi Nayan (CNS)

Ayushi Gupta (CVS)

Devi Bavishi (MSK)

Here is a list of all the procedure with their links, so you can directly access them from here.

Bookmark this page and Happy learning :)!


  1. Venepuncture
  2. Arterial puncture
  3. IV cannulation and IV infusion
  4. Nasogastric tube insertion
  5. Injection techniques
  6. Nasopharyngeal and Throat swab collection
  7. Wound swab collection
  8. Urinary Catheterization

  1. Central Venous catherisation
  2. Ascitic paracentesis
  3. Thoracocentesis
  4. Lumbar Puncture

  1. Steps common to all minor procedures
  2. Basic principles of bandaging
  3. AK Stump Bandaging
  4. BK Stump bandaging
  5. Head bandaging
  6. Magnesium sulfate and glycerine dressing
  7. Management of Cut and Lacerated Wound (CLW)
  8. Debridement
  9. Maggot removal
  10. Corn removal
  11. Lipoma excision
  12. Excision of Sebaceous cyst
  13. Incision and Drainage
  14. Suturing techniques
  15. Suture and stapler removal
  16. Surgical scrubbing
  17. ICD insertion
  18. Toe nail removal
  19. Preoperative surgical patient preparation

  1. Distal radius fracture reduction
  2. Slab application
  3. Plaster removal
  4. Trigger finger
  5. Reduction of anterior dislocation of shoulder

  1. CPR
  2. Spinal anesthesia
  3. Endotracheal intubation
  4. Subcutaneous (local) anesthesia

  1. Normal Labor
  2. Pap smear
  3. Cardiotocography
  4. Contraception - CopperT


  1. Mantoux test 
  2. Nebulization


  1. Blood donation
  2. Blood product transfusion


  1. Schirmer's test
  2. Automated perimetry
  3. Lacrimal sac syringing
  4. Tonometry


  1. Ear syringing


  1. Medicolegal Case


  1. Skin tag removal
  2. Skin biopsy