Antibiotic Lock Therapy

Antibiotic lock therapy —

The premise of ALT is to achieve sufficient therapeutic concentrations to kill microbes growing in a biofilm . ALT may be a useful adjunctive therapy together with systemic antibiotic therapy for intraluminal infections due to coagulase-negative staphylococci or gram-negative organisms in the setting of CRBSI (Catheter Related Blood Stream Infection) when the catheter cannot be removed .

ALT should not be used for extraluminal infections nor for management of infections due to S. aureus, P. aeruginosa, drug-resistant gram-negative bacilli, or Candida.

Source: Uptodate

Bhopalwala. H

Timing of Catheter Replacement in CRBSI

In general, the patient should receive antibiotic therapy for at least two to three days following device removal prior to device replacement. At the time of device replacement, the patient should be hemodynamically stable with negative blood cultures and no sequelae of bloodstream infection .In addition, for patients with CRBSI ( Catheter Related Blood Stream Infection) due to S. aureus, a new catheter may be placed if additional blood cultures demonstrate no growth at 72 hours

Source: Uptodate

Bhopalwala. H

Immunization certificate sample for electives and observerships

Hello,

Since many of you emailed me regarding the  immunization form, I thought of sharing it on Google Docs.

Step 2 CS: Neurology Case mnemonic

The following mnemonic (HDFC ST) helps me cover all bases in a Neurology case.

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 CO_{2 eliminated}/O_{2 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

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.

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

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:

• Top 10 series by AP Burkholderia

18.Drotaverin:

• 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. :)