Saturday, November 16, 2019
Clinical features of Pneumococcal Pneumonia mnemonic
Risk factors for pneumococcal pneumonia mnemonic
Monday, November 4, 2019
Saturday, November 2, 2019
Pulmonary hypertension notes
Pulmonary hypertension (PH) is defined as a resting mean pulmonary artery pressure of 25 mm Hg or greater measured during right heart catheterization.
(How I remember the number 25 - PH: 2 letters, Hyper: 5 letters).
Classification of Pulmonary Hypertension mnemonic
"A heart lung chronic thrombotic unclarity"
1: pulmonary Arterial hypertension
2: PH due to left-sided heart disease
3: PH due to lung diseases and/or hypoxia
4: Chronic thromboembolic pulmonary hypertension and other pulmonary artery obstructions
5: PH with unclear or multifactorial causes
The transpulmonary pressure gradient (TPG): The difference between mean pulmonary arterial pressure (mPAP) and left atrial pressure (LAP, commonly estimated by pulmonary capillary wedge pressure PCWP).
A TPG of >12 mmHg would result in a diagnosis of “out of proportion” pulmonary hypertension - suggesting intrinsic pulmonary vascular disease in patients with left-heart conditions associated with increased pulmonary venous pressure.
Will update post as I learn more...
-IkaN
Wednesday, July 24, 2019
Chronic thromboembolic pulmonary hypertension (CTEPH)
We will be talking about CTEPH today.
Monday, May 27, 2019
Sites of Bronchiectasis
Bronchiectasis site in lung depends upon the etiological factors
Upper lobe bronchiectasis:
Mnemonic: Upper - PCT
Upper- Upper lobe
P- Post radiation
C- Cystic fibrosis
T- Tuberculosis
Middle lobe bronchiectasis:
Mnemonic: MMC (Like BMC!)
M- Middle lobe
M- Mycobacterium avium
C- Ciliary dyskinesia
Lower lobe bronchiectasis:
Mnemonic: Left-ICA (Internal carotid artery)
Left- Lower lobe
I- Interstitial lung disease
CA- Chronic aspiration
That's all.
Thank you :)
-Demotional bloke
Tuesday, April 23, 2019
Think before you order a test: High resolution CT scan (HRCT)
Let's talk about HRCT today!
HRCT is the use of thin-section CT images (0.625-mm to 1.5-mm slice thickness) with a high spatial frequency reconstruction algorithm, to detect and characterize diseases that affect the pulmonary parenchyma and small airways.
HRCT cuts THIN slices.
Awesome, isn't it? Why not use an HD camera for every photograph?
Because it comes with a price!
Thursday, March 21, 2019
A-a Gradient
A-a gradient =[PAO2 - PaO2]
where:
A-a gradient = difference between alveolar PO2 and arterial PO2
PAO2 = alveolar PO2 (calculated from the alveolar gas equation)
PaO2 = arterial PO2 (measured in arterial blood)
PAO2 =150 - PaCo2/0.8
Normal range for A-a gradient is
10-15 mm Hg
ALL causes of hypoxemia lead to ↑ A-a gradient, EXCEPT:
Hypoventilation, high altitude, upper airway obstruction (e.g. epiglottitis from Haemophilus influenzae, or croup from parainfluenza virus)
Everything else will cause ↑ A-a gradient (e.g. shunt, V/Q mismatch, etc.).
It's much better to remember the exceptions, then everything else becomes the rule!
Also to adjust for age, the thumb rule to calculate A-a gradient is :
Age /4 plus 4
A-a gradient >30 is considered elevated regardless of age.
Bhopalwala. H
Catheter Removal Timing
Removal — Following diagnosis of catheter-related infection, catheter removal is warranted in the following circumstances :
●Severe sepsis
●Hemodynamic instability
●Endocarditis or evidence of metastatic infection
●Erythema or exudate due to suppurative thrombophlebitis
●Persistent bacteremia after 72 hours of antimicrobial therapy to which the organism is susceptible
Source :Uptodate
Bhopalwala. H
Lung Biopsy in VAP
Lung biopsy in Ventilator-associated Pneumonia may be reserved for patients in whom infiltrates are progressive despite antibiotic therapy or patients in whom a non-infectious etiology is suspected.
The purpose of acquiring tissue under these circumstances is to identify a pathogen that may have been missed with previous sampling or a pathogen that is difficult to culture (eg, fungus, herpes viruses) or to identify a noninfectious process masquerading as infection (eg, cancer, cryptogenic organizing pneumonitis, lymphangitis, interstitial pneumonitis, vasculitis).
Source: Uptodate
Bhopalwala. H
Tuesday, March 19, 2019
Catheter Related Candidemia Treatment Indications
Antibiotic Lock Therapy
Timing of Catheter Replacement in CRBSI
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 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
Sunday, December 2, 2018
Peculiar pattern of pulmonary edema
Monday, November 12, 2018
True or False #4
1. Imaging is contraindicated in pregnancy for diagnosing latent TB. T or F
2. Check for latent TB before prescribing Infliximab. T or F
ANSWERS
1. False
Diagnostic evaluation after positive test — Patients with a positive TST or IGRA must undergo clinical evaluation to rule out active tuberculosis. This includes evaluation for symptoms (eg, fever, cough, weight loss) and radiographic examination of the chest (with appropriate shielding), regardless of gestational age.
Patients with a positive TST or IGRA with no evidence of active TB may be presumed to have latent TB.
2. True
Toxicity of Infliximab includes :
Respiratory infection (possible reactivation of latent TB)
Fever
Hypotension
Last man standing wins. Keep grinding.
True or False #2
1. Herpangina involves the anterior oropharynx with grey vesicles and ulcers. T or F
2. Pleurodynia is also known as Bornholm disease. T or F
ANSWERS
1. False
Herpangina is caused by Coxsackievirus and involves the posterior oropharynx
Herpetic gingivostomatitis caused by HSV involves the anterior oropharynx and grey vesicles and ulcers
2. True
Pleurodynia — Pleurodynia is an acute enteroviral illness characterized by fever and paroxysmal spasms of the chest and abdominal muscles . Most cases occur during localized summer outbreaks among adolescents and adults. Regional and nationwide outbreaks involving a large number of older children and young adults have been reported at infrequent intervals, often separated by decades. The role of the group B coxsackieviruses, the most important cause of epidemic pleurodynia, was established in 1949 . Other agents rarely implicated in pleurodynia include echovirus serotypes 1, 6, 9, 16, and 19 and group A coxsackievirus serotypes 4, 6, 9, and 10 .
Pleurodynia can mimic more serious diseases, including bacterial pneumonia, pulmonary embolus, myocardial infarction, acute surgical abdomen, and herpes zoster infection. Most patients are ill for four to six days. Children have milder disease than adults, who are often confined to bed.
Sunday, February 4, 2018
Crepts : An Overview
Hi everyone ! Just a short summary post on Crepts. Would like to thank Upasana for suggesting this topic !
Crepts
1 . Synonyms = Rales , Crepitations , Crackles
2 . Character = Rustling/ Bubbling type of sounds
Short , sharp, interrupted sounds.
(Wet Sounds)
3 . Types =
Fine and Coarse crepts -
Differentiation is clinical - fine crepts have a shorter amplitude while Coarse crepts have a higher amplitude and are usually louder with a lower frequency.
So , if you hear crepts of mellow tone (lighter quality) , with a very small gap between two crepts they are fine.
If they are very harsh and widely spaced they're likely to be Coarse crepts.
As a thumb rule , fine crepts are generally Cardiac and Coarse are of Respiratory origin (with exceptions).
4 . Special types of Crepts :
Velcro crepts = Fine crepts of Interstitial Lung Disease
Coarse leathery crepts = Harsh Coarse crepts of Bronchiectasis
5 . Mechanism of Crepts :
- unclear but certain reasons are hypothesized.
- When an Alveolus is in a collapsed state and then bursts open it produces a crept.
So for example - in a pneumonia due to the exudates accumulated in the alveolus there is very little air in it and the alveolus is in a collapsed state at the end of expiration. Due to this, when a person inspires the collapsed alveolus and airway suddenly open with a snap and produce a sharp sound due to sudden pressure equalisation.
When many such alveoli open in a serial fashion from top to bottom we hear the typical bubbling sound of 'Crepts'.
- Older reasons - Air bubbling through exudative alveolus. But rejected as other forms of airway Obstruction like Bronchiectasis and Fibrosis causing collapsed airways also causes crepts.
6 . Causes of Crepts :
- Pneumonia / Consolidation
- Interstitial Lung Disease and Pulmonary Fibrosis
- Bronchiectasis
- Bronchitis
- Lung Abscess
- At times in COPD patients - Expiratory crepts may be heard.
Cardiac causes :
- Pulmonary edema due to Left Ventricular Failure.
7 . Cardiac vs Respiratory crepts :
Cardiac crepts are typically Basal and Bilateral , are fine crepts , associated with features of Heart Failure and may disappear on adminstering diuretics.
The opposite is true for Respiratory crepts.
Hope this was concise enough and helped !
Happy Studying!
Stay Awesome!
~ A.P.Burkholderia