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Chris D. Tzarnas

Mercy Catholic Medical Center

Publishes on Reconstructive Surgery and Microvascular Techniques, Diversity and Career in Medicine, Peripheral Nerve Disorders. 29 papers and 410 citations.

29Publications
410Total Citations

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Top publicationsby citations

Appendiceal Diverticulitis
Hamed Kabiri, Leon E. Clarke, Chris D. Tzarnas|The American Surgeon|2006
Cited by 58

The incidence of appendiceal diverticulitis in pathologic specimens is 0.004 to 2.1 per cent and is unusual in younger patients. Despite being first described in 1893, this condition is commonly dismissed by surgeons and pathologists as a variant of true appendicitis. However, appendiceal diverticulitis is a discrete clinical process that must be considered in the appropriate setting because of the much higher risk of perforation. The average age is older, the pain is often intermittent, and although it can be localized in the right lower abdominal quadrant, it is of longer duration. Although no further treatment in addition to appendectomy is needed, it is important that surgeons be aware of this condition, as the clinical presentation can be different from the classical acute appendicitis picture. Patients often seek medical treatment much later than those with classic appendicitis, and if there is a delay in establishing the correct diagnosis, perforation within the mesentery is found at the time of operation. Also, it is often mistakenly identified as carcinoma and it has higher rate of perforation and a longer convaslescence. We describe a case of a 42-year-old man and review the literature.

The Effects of Hyaluronidase on the Efficacy and on the Pain of Administration of 1% Lidocaine
Daniel R. Nevarre, Chris D. Tzarnas|Plastic & Reconstructive Surgery|1998
Cited by 42

Despite current clinical practice, there is no objective evidence to demonstrate the efficacy or pain on injection when hyaluronidase is added to lidocaine as an anesthetic combination for local anesthesia. To evaluate the usefulness of hyaluronidase added to lidocaine in affecting pain on injection and effectiveness of local anesthesia, a prospective, randomized, double blind study comparing 1% lidocaine preparations with and without hyaluronidase (15 U/cc) was conducted. A paired experiment was done with each subject receiving both treatments. Solutions of these local anesthetics were prepared. A 0.5-cc intradermal injection of each was administered to the dorsum of the nondominant hand of 25 volunteers. After showing study participants a standard pain with a peripheral nerve stimulator, pain of anesthetic infiltration was rated by the subject using a visual analog scale. The amount of tissue deformation on injection was assessed. The area of anesthetized skin surrounding each injection was measured at 1/2, 1, 2 1/2, 4 1/2, 8, and 12 minutes after injection. The area of anesthesia achieved by 1% lidocaine infiltration can be significantly enhanced by the addition of hyaluronidase at a concentration of 15 U/cc (p = 0.0003). This raises the pH of the anesthetic to a slightly more physiologic level (6.33 versus 6.20) and makes the pH closer to the pK of the lidocaine. In addition, the hyaluronidase additive significantly decreases the amount of tissue distortion (p < 0.0001) without decreasing the efficacy of anesthetic action (p = 0.01). However, adding hyaluronidase to 1% lidocaine significantly increased the pain on injection (p = 0.0002). The injections of small amounts of hyaluronidase-containing solutions in this experiment did not produce any visible effects at 5 to 7 days after injection; however, the effect of hyaluronidase upon wound healing was not studied.