Salicylate Poisoning Mechanism: Learning Toxicology

Salicylates act directly on the respiratory center in the brainstem, causing hyperventilation and respiratory alkalosis.
In addition, salicylates interfere with the citric acid cycle limiting adenosine triphosphate (ATP) production and generating lactate. Due to increased catecholamines and an increased utilization of glucose, fatty acid metabolism increases leading to ketoacidosis.
Finally, salicylates are weak acids and contribute to the acidosis through direct proton donation. These factors contribute to increased ventilation through compensation but would not be expected to cause alkalemia (overcompensation).
Although the metabolic acidosis begins in the earliest stages of salicylate toxicity, the respiratory alkalosis predominates initially, leaving the patient with a respiratory alkalosis, metabolic acidosis, and alkalemia.

Adolescents or adults presenting with respiratory acidosis early after a salicylate overdose likely have a coingested CNS depressants, experience salicylate-induced acute lung injury, or have underlying respiratory disease.

The combination of acute respiratory alkalosis, metabolic acidosis, and acidemia is an ominous finding, indicating a life-threatening salicylate overdose.

Reference: Tintinalli

Lithium Toxicity: Learning Toxicology

A 45ym known with MDP
, on Lithium ,
He took an unknown amount of Lithium to commit suicide .

The following is/are true or false regarding Lithium toxicity :

1-Both hypothyroidism and hyperthyroidism, as well as calcium disturbances secondary to hyperparathyroidism, have been reported with lithium poisoning.

True

2-Flattened T waves, prolonged QTc intervals, and bradycardia are common.

False,
Are rare

3-Phenobarbitone is the first line therapy for seizures. 

False.
Benzodiazepine

4-Patients with acute lithium toxicity are at risk for developing nephrogenic diabetes insipidus (NDI)

False
with chronic toxicity

5-Whole bowel irrigation with polyethylene glycol (PEG) solution are not effective in patients with large acute ingestions .

False
Effective

6-Serum lithium concentrations correlate more closely with clinical signs in patients with chronic toxicity

True
For chronic toxicity

7-The syndrome of irreversible lithium effectuated neurotoxicity (SILENT) consists of prolonged neurologic and neuropsychiatric symptoms following lithium toxicity.

True,
Fact

8-Lithium poisoning is  associated with elevations in cardiac biomarkers and  left ventricular dysfunction.

False
Is not

9-Severe lithium intoxication can cause nonconvulsive status epilepticus, and encephalopathy.

True

Commonly injured structures in Wrist: Orthopedics

Commonly injured structures in Wrist: Orthopedics

The scapholunate ligament is the most commonly injured ligament in the wrist, usually the result of a fall on an outstretched hand. The scapholunate ligament is an intrinsic ligament binding the scaphoid and lunate together between the proximal and distal rows of carpal bones. Scapholunate dissociation is diagnosed radiographically with a widening of the scapholunate space greater than 3 mm. This is also known as the Terry Thomas sign. 

Injuries to the triquetrolunate ligament are less common, and usually result from a fall onto an outstretched and dorsiflexed hand. This injury may produce pain on the ulnar aspect of the wrist and can be confused with injury to the triangular fibrocartilage complex. 

The Space of Poirier refers to the area between the two palmar arches at the junction of the capitate and lunate, and is vulnerable to ligamentous disruption.

Laceration of Tendons: Orthopedics

Laceration of Tendons

Mallet finger is the injury resulting from laceration or rupture of the extensor tendon over Zone I, the distal phalanx, or distal interphalangeal joint. This injury causes the distal interphalangeal joint to be flexed at 40 degrees. It is the most common tendon injury in athletes.

Swan neck deformity may result from chronic untreated Mallet finger. 

Boutonniere deformity results from an injury in Zone III over the proximal interphalangeal joint. Injury of the central tendon and disruption of the lateral bands allow flexion as well as the flexor digitorum profundus to function unopposed. There is retraction of the extensor hood and resultant extension of the metacarpophalangeal and distal interphalangeal joints. Gamekeeper’s thumb is the rupture of the ulnar collateral ligament. This occurs as the result of radial deviation of the metacarpophalangeal joint.

Iron Poisoning

A 29 yf ingested an unknown quantity of iron pills to commit suicide.
The following is /are true or false :

1- Indications for deferoxamine therapy in pregnant patients are different from those for other patients

False,
 Indications for deferoxaminetherapy in pregnant patients are the same as those for other patients

2-Significant number of pills on abdominal radiograph is an indication of deferoxamine treatment.

True

3-Many adult iron preparations are too large to be removed from the holes in an orogastric lavage tube, limiting the value of lavage in this setting.

True

4-The etiology of the shock state may be hypovolemic, distributive, or cardiogenic, depending on the time of onset 

True

5-"Relative stability" or "Quiescent phase") occurs from 72 to 96 hours after ingestion and is a period of apparent recovery.

False,
6-24 hours

6-Bowel obstruction: two to eight weeks after ingestion is characteristics of stage 4

False,
Stage 5

7-Ferrous gluconate =(12 percent elemental iron) &
Ferrous sulfate (20 percent elemental iron)&
Ferrous fumarate (33 percent elemental iron

True

8-Deferoxamine challenge test (DFO) is  advocated as a method to confirm the ingestion of a toxic dose of iron.

False,
Is no longer advocated

9-Iron is not well adsorbed by charcoal

True

Spontaneous Bacterial Peritonitis

SBP

Management of tracheostomy tubes: A Minute of Meducation

Management of tracheostomy tube: 

A Minute of Meducation:

Tracheostomy tube obstruction with mucous plugging is common.

How to Manage it:

It is best treated with preoxygenation (as suctioning may cause transient hypoxia) and then placing of sterile saline into the trachea and suctioning through large flexible catheters through the inner cannula. If this does not succeed, remove the inner cannula and clean with hydrogen peroxide and rinse with water. Sometimes, the entire tracheostomy tube needs to be removed and cleaned. Tracheostomy tubes less than 7 days in maturation should be manipulated only by otolaryngology surgeons. Remember 'Pediatric' tracheostomies do not have inner cannulas.