Q) If ph >7.4, How much does plasma potassium concentration change for every 0.1 unit increase of the extracellular pH ?
a) Potassium decrease by 0.3meq/l
b) K+ increase by 0.3 meq/l
c) Potassium decrease by 1.5 meq/l
d) K+increase by 1.5 meq/l
Free answer
a
Acid-base disturbances cause potassium to shift into and out of cells. This is called internal potassium balance and was discovered in 1956.
In alkalosis (increase in ph,) K+ falls and in Acidosis potassium concentration will increase. For every 0.1 fall in ph, K+ increases by 0.3-0.6 meql/l
Metabolic acidosis- in a plasma potassium concentration that is elevated in relation to total body stores.
Q) Which modality has no part in management of corrosive injury of esophagus?
a) Repeated Endoscopies routinely
b) Esophagectomy in some cases
c) Early emergency surgery routinely
d) Steroid use routinely
C
In corrosive injury of the esophagus, routine early emergency surgery is generally not indicated. The primary approach involves stabilization, assessing the extent of injury, and supportive care. Surgery is reserved for specific complications, such as perforation or severe necrosis.
Other than the need for emergency surgery for bleeding or perforation, elective oesophageal resection should be deferred for at least 3 months until the fibrotic phase has been established.
Oesophageal replacement is usually required for very long or multiple strictures. Resection can be difficult because of perioesophageal inflammation in these patients.
Regular endoscopic examinations are the best way to assess stricture development .
Significant stricture formation occurs in about 50% of patients with extensive mucosal damageo Corrosives can cause significant pharyngolaryngeal oedema
In unusual circumstances, e.g. with extensive necrosis after corrosive ingestion, emergency oesophagectomy may be necessary.
Alkali and acidic injuries to the esophagus, both leading causes of corrosive stricture of the esophagus, differ in their effects due to distinct chemical reactions with tissue.
Mechanism of Injury
Alkali Injuries: Ingested alkalis (e.g., drain cleaners) cause liquefactive necrosis, where tissue rapidly breaks down. This process allows alkalis to penetrate deep into the esophageal layers, often causing severe, widespread injury that extends to adjacent tissues. As a result, alkali injuries frequently lead to extensive scarring and stricture formation over time, significantly impacting the esophageal lumen.
Acidic Injuries: Acids like hydrochloric acid cause coagulative necrosis, resulting in protein denaturation and an eschar formation. This eschar limits acid penetration depth, typically causing more superficial injury compared to alkalis. However, mucosal damage can still be severe, leading to ulceration and potential esophageal stricture over time, especially if the injury affects the lower esophagus.
