Monday, March 18, 2019

Right to left shunt causing Hypoxemia

A right-to-left shunt exists when blood passes from the right to the left side of the heart without being oxygenated. There are two types of right-to-left shunts:

●Anatomic shunts exist when the alveoli are bypassed. Examples include intracardiac shunts, pulmonary arteriovenous malformations (AVMs), and hepatopulmonary syndrome.

●Physiologic shunts exist when non-ventilated alveoli are perfused. Examples include atelectasis and diseases with alveolar filling (eg, pneumonia, acute respiratory distress syndrome).

Right-to-left shunts cause extreme V/Q mismatch, with a V/Q ratio of zero in some lung regions. The net effect is hypoxemia, which is difficult to correct with supplemental oxygen.

The degree of shunt can be quantified from the shunt equation:

Qs/Qt  =  (CcO2  -  CaO2)  ÷  (CcO2  -  CvO2)

where Qs/Qt is the shunt fraction, CcO2 is the end-capillary oxygen content, CaO2 is the arterial oxygen content, and CvO2 is the mixed venous oxygen content. CaO2 and CvO2 are calculated from arterial and mixed venous blood gas measurements, respectively. CcO2 is estimated from the PAO2.

Source: UpToDate

Bhopalwala. H

Causes of Hypoventilation

Hypoventilation — 

The lung alveolus is a space in which gas makes up 100 percent of the contents. This means that once the partial pressure of one gas rises, the other must decrease. Both arterial (PaCO2) and alveolar (PACO2) carbon dioxide tension increase during hypoventilation, which causes the alveolar oxygen tension (PAO2) to decrease. As a result, diffusion of oxygen from the alveolus to the pulmonary capillary declines with a net effect of hypoxemia and hypercapnia. Because the respiratory quotient (Defined as CO2 eliminated/O2 consumed) is assumed to be 0.8, hypoventilation affects PaCO2more than O2.

Hypoxemia due to pure hypoventilation (ie, in the absence of an elevated A-a gradient) can be identified by two characteristics. First, it readily corrects with a small increase in the fraction of inspired oxygen (FiO2). Second, the paCO2 is elevated. An exception exists when the hypoventilation is prolonged because atelectasis can occur, which will increase the A-a gradient . Abnormalities that cause pure hypoventilation include:

●CNS depression, such as drug overdose, structural CNS lesions, or ischemic CNS lesions that impact the respiratory center

●Obesity hypoventilation (Pickwickian) syndrome

●Impaired neural conduction, such as amyotrophic lateral sclerosis, Guillain-Barré syndrome, high cervical spine injury, phrenic nerve paralysis, or aminoglycoside blockade

●Muscular weakness, such as myasthenia gravis, idiopathic diaphragmatic paralysis, polymyositis, muscular dystrophy, or severe hypothyroidism

●Poor chest wall elasticity, such as a flail chest or kyphoscoliosis

Bhopalwala. H

Wednesday, March 13, 2019

Types of Sphenoid Sinues.

Hello Guy's!

Here's a sneak peek into the world of Neurosurgery!

In cases of Pituitary Adenomas, the general surgical approach is a TransNasal TransSphenoidal Approach for the excision of the lesion.

To know the type of sphenoid sinus is an important step in the pre-operative planning for the surgery. It also helps in estimating the site where we are most likely to encounter the tumor and the pituitary gland.

Hamburger classified 3 types of pneumatization based on its relationship to the sella turcica.

1)Conchal (rudimentary or absent sphenoid sinus)

2)Presellar (a posterior sphenoid sinus wall that is separated from sella by thick bone).

3)Sellar (a posterior sphenoid sinus wall that is adjacent to sella).

That's all for now... Time to Scrub.

Let's learn Together!

~Medha Vyas.



Monday, March 11, 2019

Restrictive vs Liberal approach to transfusion in Sepsis

Hello everyone, 

Here are some studies on approach to blood transfusion during sepsis:

One multicenter randomized study of 998 patients with septic shock reported no difference in 28-day mortality between patients who were transfused when the hemoglobin was ≤7 g/dL (restrictive strategy) and patients who were transfused when the hemoglobin was ≤9 g/dL (liberal strategy) . The restrictive strategy resulted in 50 percent fewer red blood cell transfusions (1545 versus 3088 transfusions) and did not have any adverse effect on the rate of ischemic events (7 versus 8 percent).

One randomized trial initially reported a mortality benefit from a protocol that included transfusing patients to a goal hematocrit >30 (hemoglobin level 10 g/dL) . However, similarly designed studies published since then reported no benefit to this strategy. 

Bhopalwala. H

Source: UpToDate 

Norepinephrine in ICU

Norepinephrine (noradrenaline) Levophed

8 to 12 mcg/minute (0.1 to 0.15 mcg/kg/minute)

A lower initial dose of 5 mcg/minute may be used, eg, in older adults 2 to 4 mcg/minute (0.025 to 0.05 mcg/kg/minute) 35 to 100 mcg/minute (0.5 to 0.75 mcg/kg/minute; up to 3.3 mcg/kg/minute has been needed rarely)

Initial vasopressor of choice in septic, cardiogenic, and hypovolemic shock.
Wide range of doses utilized clinically.

Must be diluted; eg, a usual concentration is 4 mg in 250 mL of D5W or NS (16 micrograms/mL).

Bhopalwala. H

Milrinone in ICU

Inotrope (nonadrenergic, PDE3 inhibitor)

Milrinone Primacor

Optional loading dose: 50 mcg/kg over 10 minutes (usually not given) 0.125 to 0.75 mcg/kg/minute

Alternative for short-term cardiac output augmentation to maintain organ perfusion in cardiogenic shock refractory to other agents.

Increases cardiac contractility and modestly increases heart rate at high doses; may cause peripheral vasodilation, hypotension, and/or ventricular arrhythmia.

Renally cleared; dose adjustment in renal impairment needed.

Must be diluted; eg, a usual concentration is 40 mg in 200 mL D5W (200 micrograms/mL); use of a commercially available pre-diluted solution is preferred.

Bhopalwala. H

Dobutamine in ICU

Dobutamine Dobutrex

0.5 to 1 mcg/kg/minute

(alternatively, 2.5 mcg/kg/minute in more severe cardiac decompensation) 2 to 20 mcg/kg/minute
20 to 40 mcg/kg/minute;

Doses >20 mcg/kg/minute are not recommended in heart failure and should be reserved for salvage therapy

Initial agent of choice in cardiogenic shock with low cardiac output and maintained blood pressure.
Add-on to norepinephrine for cardiac output augmentation in septic shock with myocardial dysfunction (eg, in elevated left ventricular filling pressures and adequate MAP) or ongoing hypoperfusion despite adequate intravascular volume and use of vasopressor agents.

Increases cardiac contractility and rate; may cause hypotension and tachyarrhythmias.
Must be diluted; a usual concentration is 250 mg in 500 mL D5W or NS (0.5 mg/mL); use of a commercially available pre-diluted solution is preferred.

Bhopalwala. H

Vasopressin in ICU

Vasopressin (arginine-vasopressin) Pitressin, Vasostrict

0.03 units per minute (alternatively 0.01 to 0.03 units/minute initially) 0.03 to 0.04 units per minute (not titrated)
0.04 to 0.07 units/minute;

Doses >0.04 units/minute can cause cardiac ischemia and should be reserved for salvage therapy

Add-on to norepinephrine to raise blood pressure to target MAP or decrease norepinephrine requirement. Not recommended as a replacement for a first-line vasopressor.
Pure vasoconstrictor; may decrease stroke volume and cardiac output in myocardial dysfunction or precipitate ischemia in coronary artery disease.

Must be diluted; eg, a usual concentration is 25 units in 250 mL D5W or NS (0.1 units/mL)

Bhopalwala. H

Sunday, March 10, 2019

LMR (Last minute revision) Stuff for obstetrics and gynecology drugs

Hello Awesomites!

In LMR sessions, I will share final year MBBS Viva things on drugs and specimen.You can add your list in the comments below. 
Today I will share the Obstetric and gynaecology viva on drugs. 
Lets get started.

1.Tranexamic acid and mefanemic acid combination

Tranexamic acid:
  • anti-fibrinolytic
  • Amino caproic acid derivative 
  • CONVERTS plasmin to plasminogen
  • given during menstruation
  • Adverse effect:- Intracranial thrombosis

Mefanemic Acid:
  • COX inhibitor.
  • Given during menstruation
  • Adverse effect:- dyspepsia,gastric ulcer
USE:-
  • Ovulatory cycles of DUB
  • Post IUCD bleeding
  • Post sterilization mennorhagia
  • Fibroid
2.Doxylamine and Vitamin B6 combination

Doxylamine is anti histaminics that has effects on acetylcholine and serotonin release. And you know their receptor is present on CTZ centers.
Vitamin B6 is pyridoxine.
In pregnancy and poor diet the amount decreases.

USE:- Emesis during pregnancy at bedtime (not more than 2 tablet in a day).

3.Dinoprostone gel
  • Prostaglandin E2
  • 500 micro gram into the cervical canal below the level of internal os
  • Or 1-2 mg in the posterior fornix 
  • maximum 3 doses 6 hourly
  • Applied in posterior fornix when membrane is ruptured
  • applied in internal os when membrane is intact
  • USE- Cervical ripening in IOL.
  • Before and after CTG monitoring is must.
  • C/I- Previous CS, Impending scar rupture,fetal distress,asthma,severe heart disease
S/E- hyperstimulation of uterus,fetal distress

4.L-Arginine+Folic acid+isothiocyanidin
  • L-Arginine is precursor for Nitric oxide generation that will lead to vasodialtion
  • USE: In IUGR, Severe oligohydroamnios, preventing pre-eclampsia
5.Misoprostol

  • PGE1
  • ROUTE= sublingual,vaginal,rectal (never parentral)
  • S/E:Fever,chills,shivering
  • Teratogenic: Mobius syndrome (Category X drug)
  • USES:-
  1. OBSTETRIC USES:
  • Termination of pregnancy
  • PPH prevention and treatment.
     2.GYNECOLOGICAL USE:
  • Pe hysterectomy
  • IUI
  • Cervical pregnancy
    3.GIT USE:
  • Treatment of peptic ulcer caused by NSAIDs.
6.Frusemide:
  • Loop diuretic.
  • prior to blood transfusion in severe anemia
  • congestive cardiac failure
  • used in complications not as anti hypertensives
  • PIH with massive edema
7.Clindamycin+Clotrimazole 
  • USE: Mixed bacterial and fungal vaginosis 
8.Omeprazole+Ondansetron:
  • USE: GERD, peptic ulcer
9.Heparin:
  • Injectable Anti-coagulant
  • In 1st trimester
  • Antidote: Protamine sulfate
  • USE: DVT, APLA, PE, recurrent abortion (Prophylaxis:ASPIRIN+HEPARIN)
10.Iron folic acid:
  • Prophylactic: 100mg elemental iron+500 micro gram folic acid daily from 2nd trimester throughout pregnancy +6 month postpartum
  • Treatment: Oral  iron 200 mg elemental iron daily
  • Folic acid deficiency lead to abortions, abruptio, IUGR, NTD
  • In folic acid deficiency dose is 4000mg
11.Anti-D Immunoglobulin:
  • IgG, intramuscular
  • 300 micro gram=15 ml of D positive red cell/ 30 ml of fetal whole blood 
  • If ICT -VE at 28 weeks
12.Hydrocortisone:
  • 2 doses 12 mg betamethasone i/m 24 hours apart
  • 4 doses 6 mg dexamethasone 12 hours apart
13.Sodium Bicarbonate:
  • IV for Heart resuscitation, poor kidney function, Cocaine toxicity
  • Poisoning cases
  • Reviving newborn
  • Preventing chemotherapy side effects
  • Hyperkalemia
  • metabolic acidosis
14.Diazepam:
  • Central Muscle relaxant and anti convulsant, Tranquilizer
  • S/E:- Maternal (Hypotension) and Fetal (Respiratory depression, hypotonia)
15.Nifedipine:
  • Direct arteriolar vasodilator
  • Calcium channel blocker
  • USE:Tocolytics
  • A/E: Flushing, Hypotension, headache, Inhibition of labor
16.Labetalol:
  • Anti-hypertensive
  • combined alpha and beta blocker
  • orally 100mg tid to 2.4 g daily
  • USE: Hypertension and hypertensive crisis
  • S/E:tremor, headache, CCF.
  • C/I: Hepatic disorder, asthma, CCF
17.Magnesium Sulphate:
  • Anti-spasmodic (PDE-4 Inhibitor)
  • Enhance cervical dilatation during childbirth
  • USE: Acute renal colicky, augment labor.
19.Oxytocin:

20.Methergine:

21.Prostaglandins:


More is coming up !
-Upasana Y. :)

Friday, March 8, 2019

Classification Criteria for Adult Still Disease

●Yamaguchi criteria – The Yamaguchi criteria require the presence of five features, with at least two being major diagnostic criteria . In addition, the presence of any infection, malignancy, or other rheumatic disorder known to mimic ASD in its clinical features precludes the diagnosis of ASD, at least for the purpose of research.

The four major Yamaguchi criteria are:

•Fever of at least 39ºC (102.2ºF) lasting at least one week

•Arthralgias or arthritis lasting two weeks or longer

•A nonpruritic macular or maculopapular skin rash that is salmon-colored in appearance and usually found over the trunk or extremities during febrile episodes

•Leukocytosis (10,000/microL or greater), with at least 80 percent granulocytes

The minor Yamaguchi criteria include:

•Sore throat

•Lymphadenopathy

•Hepatomegaly or splenomegaly

•Abnormal liver function studies, particularly elevations in aspartate and alanine aminotransferase and lactate dehydrogenase concentrations

•Negative tests for antinuclear antibody (ANA) and rheumatoid factor (RF)

Bhopalwala. H

Useful Pediatrics mobile apps


Technology is a crucial part of our life nowadays. Below are some apps that can make a pediatric student/resident/specialist life easier :D


1- Uptodate

The famous app for the well-known website “ Uptodate” where you can get peer-reviewed data for nearly any subject you may think of. It also has a section for adult and pediatric medication dosing which can be helpful. Another nice section is the patient education section that is really helpful to explain complex medical things to parents in layman terms.
  
Keep in mind that you ll need an account which may be provided to your through your residency program, a friend or you yourself paying for Uptodate.

2- Medscape

The app for the amazing peer-reviewed website Medscape. Just create an account and search for any disease you like (epidemiology, incidence, clinical presentation, treatment, prognosis..etc).

3- Medstudy and Medstudy audio apps

The apps for the Medstudy book series. Listen to a medstudy chapter on your way somewhere or revise some pages through your app. These apps require an active Medstudy subscription

4- PCO / Pediatric Care Online 

A nice app by the American Academy of Pediatrics (AAP). Through this app, you get access to “Red Book”, one of the most famous books/sources for Infectious diseases and their treatments, “Bright futures” which is helpful to hone your skills in your continuity clinic among many other things.
  
To get access completely, you need an AAP account which will be provided by your residency program. 

5- Heartpedia

A great app from Cincinnati Children’s Hospital. Through this app, you can have a 3D visual construction of the most common congenital heart anomalies (ASD, VSD, PDA, COA..etc). Choose the angle you like, zoom in or out. The app also has links to youtube videos explaining the defect. This app is particularly very helpful if you are trying to explain a congenital heart defect for a parent and for further clarification to a student.   

6- CDC Vaccine Schedules (Vaccinations, catchup, contraindication)

Vaccines are a vital part of any Well Child Check visit. This app from the CDC has all the tables for Pediatrics and Adult vaccines including the catch-up schedule as well as the contraindications for these vaccines.

An amazing website to help with this is : https://www.vacscheduler.org/
Just enter the age of the patient, the vaccines that he/she got and the website will tell you what the patient needs

7- Bilicalc

For nursery folks, you should have Bilicalc on your smart-phones, it is the best app to know the lightable levels (LL) for babies. Just enter the baby’s hours of life as well as the bili result and wait for the app to tell you the LL for low, medium and high risk curves.

It does the same job that www.bilitool.org does.

 8- eBooks by inkling

This app acts like a “template” through which you can read different books. A must-to-have book is Harriet-Lane (every Pediatrician should have this book :D). To access it, use the code that is located on the first page of the book’s hardcopy. It is given by most residency programs to the residents. If not, you should consider buying it for sure.
  
9- MDcalc

Scoring systems in medicine are endless. This is the best app that can be your savior. Are you looking for: Westley’s croup scoring? Pediatric Asthma scoring? Calculating maintenance fluids for a child? Well, you just hit the jackpot.
 
10- GoodRx

Help your patients find coupons so they can buy the medications they need at a lower price.
  
11- Google keep

Although not medical but this app is wonderful to take notes and to create lists. Write all your lists in one place and use different colors. Synchronize all your notes/lists with any other device: tablet, laptop..etc. Organize your life, a much 
  
12- Anki

Another non medical app, Anki is a wonderful flashcards app. It acts like a template that you can create flashcards with or use already pre-made shared cards. Add your notes to any deck you like, synchronize between your devices and have your info with you everywhere. 


 Comment below if you have any apps or websites that may be helpful for pediatricians or anyone who is interested in Pediatrics :)


-Murad




Wednesday, March 6, 2019

HAP and VAP

Pneumonia types — The 2016 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) guidelines distinguish the following types of pneumonia :

●Hospital-acquired (or nosocomial) pneumonia (HAP) is pneumonia that occurs 48 hours or more after admission and did not appear to be incubating at the time of admission.

●Ventilator-associated pneumonia (VAP) is a type of HAP that develops more than 48 hours after endotracheal intubation.

Bhopalwala. H

Saturday, March 2, 2019

qSOFA Score for Sepsis

The qSOFA (quick Sequential Organ Failure Assessment) score is easy to calculate since it only has three components, each of which are readily identifiable at the bedside and are allocated one point:

●Respiratory rate ≥22/minute

●Altered mentation

●Systolic blood pressure ≤100 mmHg

Bhopalwala. H