Digital Blocks

Digital Blocks

Digital blocks are the preferred type of anesthesia for procedures done distal to the PIP joint. Caution should be used when giving digital blocks after injury to the digital artery that may require revascularization because the digital nerves and arteries run together. Digital blocks should also not be given when there is an infection around the MP joint.

A 25-gauge, 1½-in. needle is inserted distally in the web space where the skin innervation is less dense than in the palm (Fig. 1). The needle is advanced under the dorsal skin to the MP joint and 1 mL of anesthetic is injected into the subcutaneous space. The needle is withdrawn half way and directed palmarly between the MP joints. The needle is advanced until it is almost subcutaneous. Two to three milliliters are injected palmarly. The procedure is then repeated on the other side of the digit.

In the thumb, the two digital nerves are more palmar and closer together than in the digit. The ulnar digital nerve lies just palmar to the first web and the radial digital nerve lies just radial to the midline. Both nerves can be blocked by inserting the needle from ulnar to radial into the first web space at the MP joint. Two to three milliliters of anesthetic are injected transversely along the MP crease. Dorsal injections are given via sites at the radial and ulnar borders of the MP joint. Care should be taken to not give a “ring block,” or circumferential injection at the MP joint. This block may tightly compress the tissues and compromise vascularity of the digit. As with any block in the hand, no effort is made to elicit paresthesias during the injection. The needle should be withdrawn and replaced in order to avoid injection into the nerve if paresthesias are elicited.

What do you know about Thyroid-stimulating hormone? , (also known as TSH or thyrotropin )

What do you know about Thyroid-stimulating hormone? , (also known as TSH or thyrotropin ) :

 Thyroid-stimulating hormone is a hormone that stimulates the thyroid gland to produce thyroxine (T4), and then triiodothyronine (T3) which stimulates the metabolism of almost every tissue in the body.

 TSH stimulates the thyroid gland to secrete the hormones thyroxine (T4), which has only a slight effect on metabolism. T4 is converted to triiodothyronine (T3), which is the active hormone that stimulates metabolism. About 80% of this conversion is in the liver and other organs, and 20% in the thyroid itself .

 In adults, a standard reference range is between 0.4 and 3.0 µIU/mL (equivalent to mIU/L), but values vary slightly among labs. In the UK, guidelines issued by the Association for Clinical Biochemistry suggest a reference range of 0.4-4.5 mIU/L.

 The National Academy of Clinical Biochemistry (NACB) stated that it expected the normal range for adults to be reduced to 0.4–2.5 µIU/mL, because research had shown that adults with an initially measured TSH level of over 2.0 µIU/mL had "an increased odds ratio of developing hypothyroidism over the [following] 20 years, especially if thyroid antibodies were elevated"

 TSH concentrations in children are normally higher than in adults. In 2002, the NACB recommended age-related reference limits starting from about 1.3 to 19 µIU/mL for normal-term infants at birth, dropping to 0.6–10 µIU/mL at 10 weeks old, 0.4–7.0 µIU/mL at 14 months and gradually dropping during childhood and puberty to adult levels, 0.4–4.0 µIU/mL

 Diagnosis of disease :

 TSH concentrations are measured as part of a thyroid function test in patients suspected of having an excess (hyperthyroidism) or deficiency (hypothyroidism) of thyroid hormones. Interpretation of the results depends on both the TSH and T4 concentrations. In some situations measurement of T3 may also be useful.

 Monitoring

 The therapeutic target range TSH.. level for patients on treatment ranges between 0.3 to 3.0 μIU/mL .

 For hypothyroid patients on thyroxine, measurement of TSH alone is generally considered sufficient. An increase in TSH above the normal range indicates under-replacement or poor compliance with therapy.

 A significant reduction in TSH suggests over-treatment. In both cases, a change in dose may be required.

 For hyperthyroid patients, both TSH and T4 are usually monitored.

 Therapeutic :

 A synthetic drug called recombinant human TSH alpha (rhTSHα or simply rhTSH, (trade name Thyrogen), is manufactured by Genzyme Corp..

 The rhTSH is used to treat thyroid cancer.