Pediatrics- pyloric stenosis
A 3-month old infant who has been vomiting for four days is scheduled for a pyloromyotomy.
1. What fluid and electrolyte abnormalities are expected?
2. What type of fluid will you use to correct abnormalities?
3. What is your endpoint of therapy?
4. What technique of induction and intubation will you use?
5. A colleague says all of these infants should be intubated awake. What is your response?
Local anesthetic drug toxicity
A patient develops tinnitus during induction of axillary block with 1.5% lidocaine.
1. What is the significance of this?
2. What are your next steps?
3. Would you change drugs?
4. Would you switch to intravenous regional block?
5. Compare the hazards of different types of arm blocks from the standpoint of local anesthetic toxicity.
During attempted cannulation of the right internal jugular vein, you puncture the carotid artery in a patient who is to be heparinized intraoperatively.
1. What is your management?
2. Would you proceed with the case?
3. How does heparin anticoagulate?
Heparin binds to antithrombin III and the activated forms of factors II, X, XI, XII, and XIII, having an anticoagulant effect of about ninety minutes. It may produce qualitative or quantitative platelet abnormalities.
4. The patient is resistant to heparinization. What is the defect?
Antithrombin III deficiency
5. What is the treatment? Fresh frozen plasma.
5. What tests measure the intrinsic and common pathways? For the intrinsic pathway, phospholipid is added to the patient's plasma, and the time taken for clot formation is taken. Decreased fibrinogen and dysfibrinogenemias prolong both intrinsic and extrinsic pathways. The partial thromboplastin time, or PTT, measures all factors of the intrinsic and common paths, except factor XIII. A normal value is 40-100 seconds. The normal activated PTT is 25-35 seconds, and the activated clotting time is normally 90-120 seconds.
6. What tests measure the extrinsic and common pathways? The normal prothrombin time is 10-12 seconds, and the international normalized ratio is used to measure therapeutic ranges for anticoagulant therapy.