Grenith Zimmerman

Accuracy of intraocular lens power prediction using the Hoffer Q, Holladay 1, Holladay 2, and SRK/T formulas

PURPOSE: To compare the accuracy of intraocular lens (IOL) power calculations using 4 formulas: Hoffer Q, Holladay 1, Holladay 2, and SRK/T. SETTING: Tertiary care center. METHODS: This study was a retrospective comparative analysis. Immersion ultrasound biometry (axial length, anterior chamber depth, and lens thickness), manual keratometry, and postoperative manifest refraction were obtained in 643 eyes of consecutive patients who had routine uneventful cataract surgery with implantation of 1 of 2 IOLs using the same operative technique by the same surgeon. Biometric data were entered into each of the 4 IOL power calculation formulas, and the results were compared to the final manifest refraction. An optimized lens constant was used for each formula. Results were also stratified into groups of short, average, medium long, and very long axial length <22.0 mm, 22.0 to <24.5 mm, 24.5 to 26.0 mm, and >26.0 mm, respectively). RESULTS: No formula was more accurate than the others as measured by mean absolute error. The formulas were also equally accurate when eyes were stratified by axial length. CONCLUSION: The 4 IOL power formulas provided equivalent refractive results in the entire group of eyes and in the subsets of axial lengths tested.

Relationship Between Quality of Life and Depression in Patients With Head and Neck Cancer

Objective: This study describes the relationship between health‐related quality of life (HRQOL) and depression in patients following major surgery for head and neck cancer.

Factors related to quality of life and functional status in 50 patients with head and neck cancer.

Quality of life (QOL) and functional status (FS) have become important outcome measures in cancer therapy. Valid and reliable instruments recently have been developed for examining QOL and FS in patients with head and neck (HN) cancer. The present study evaluated the relationships of QOL and FS to physical and psychological variables assumed to affect QOL and FS. Fifty patients were evaluated up to 6 years after HN cancer surgery using one general QOL instrument and three HN‐specific instruments. Analysis of variance showed physical variables such as tumor site to be related to HN‐specific scores, while psychosocial variables such as marital status were related to general QOL scores (P≤.05). Several relationships were seen between physical or psychosocial variables and FS or QOL measures; however the relationships were not as strong or direct as expected.

Pegaspargase‐induced pancreatitis

BACKGROUND The purpose of this study is to report the incidence of pancreatitis in patients treated with pegaspargase in our hospital during a 2-year period. PROCEDURE We identified episodes of pancreatitis related to the intramuscular administration of pegaspargase 2,500 IU/m(2) for the treatment of childhood hematological malignancies during a 2-year period (May 1996-April 1998). Patients were evaluated clinically and by sequential serum amylase and lipase determinations and radiographic examinations. For comparison, episodes of pancreatitis in patients who only received native Escherichia coli L-asparaginase were examined during the same time period. RESULTS Nine children with acute lymphoblastic leukemia (ALL) of 50 (18%) patients who received pegaspargase were diagnosed to have pancreatitis. All had prior therapy with native L-asparaginase. These children developed symptoms consisting of abdominal pain, nausea, vomiting, and decreased appetite within a median of 15 days from the onset of pegaspargase administration. Six patients became symptomatic after their initial dose. Seven patients developed severe or unacceptable toxicity (grades 3 and 4), measured by increased amylase (>2 times normal) and lipase levels or radiographic evidence of pancreatic inflammation or pseudocyst. One patient also developed hyperammonemia and encephalopathy. In contrast, only one out of 52 (1.9%) ALL patients who received native E. coli L-asparaginase during the same time period developed pancreatitis (P= 0.007). CONCLUSION Clinicians should be aware of a possible higher incidence of pancreatitis associated with pegaspargase.

Radiographic and aerodynamic measures of velopharyngeal anatomy and function following Furlow Z-plasty.

&NA; Recent studies have shown that the Furlow doubleopposing Z‐plasty has several advantages that make it an attractive procedure for cleft palate repair and treatment of velopharyngeal insufficiency in selected cases. The anatomic changes associated with this procedure have never been documented prospectively. The purpose of this study was to describe radiographic dimensions of the velopharynx and aerodynamic measures of velopharyngeal function in a group of patients before and after Furlow Z‐plasty for the treatment of velopharyngeal insufficiency. Twelve consecutive patients with cleft palate and velopharyngeal insufficiency, ranging in age from 3 to 19 years, were selected as candidates for Furlow Z‐plasty based on perceptual, endoscopic, and radiographic findings. Eight patients had repaired cleft palate with a residual muscle diastasis and four patients had unrepaired submucous cleft palate. Subjects received aerodynamic and cephalometric assessments before and after Z‐plasty. Cephalometric x‐rays were measured for velar length, thickness, and pharyngeal depth. Mean nasal airflow during pressure consonants (Vn) was calculated from pressure/flow studies, and patients were categorized as having complete closure (<10 cc/sec Vn) or incomplete closure (>10 cc/sec Vn). After Z‐plasty, there was a significant increase in velar length (p = 0.002) and velar thickness (p = 0.001). After surgery, patients with complete velopharyngeal closure had significantly greater velar length than the incomplete closure group (p = 0.05) with nearly twice the increase in length. Similarly, following surgery, the complete closure group had significantly greater thickness than the incomplete closure group (p = 0.01), with a greater postoperative increase in velar thickness (p = 0.005). Finally, there was a significant negative correlation between percent increase in length and percent increase in thickness for patients in the complete closure group (r = ‐0.91, p = 0.03). Findings demonstrate that following Furlow Z‐plasty, patients with cleft palate and velopharyngeal insufficiency obtained significant increases in velar length and thickness. Greater velar length and greater velar thickness both were associated with complete velopharyngeal closure. Patients in the complete closure group tended to demonstrate large percent gains in either length or thickness or moderate gains in both. Patients in the incomplete closure group tended to demonstrate relatively small percent gains in both dimensions. Results suggest there may be important anatomic features (such as pharyngeal depth/velar length ratio) that can be evaluated before surgery to predict which patients may be most likely to benefit from Furlow Z‐plasty as a form of treatment for velopharyngeal insufficiency. (Plast. Reconstr. Surg. 106: 539, 2000.)

The role of nitric oxide in skin blood flow increases due to vibration in healthy adults and adults with type 2 diabetes.

BACKGROUND We recently demonstrated concomitant increases in skin blood flow and nitric oxide (NO) production in young healthy adults in response to externally applied vibration of the forearm. Research has shown that adults with type 2 diabetes exhibit depressed NO production and vascular responses to NO. We hypothesized that subjects with type 2 diabetes would display lower than normal increases in skin blood flow to externally applied vibration. RESEARCH DESIGN AND METHODS Therefore, the purpose of this study was to compare 20 male and female, age- and body mass index-matched normal adults and adults with type 2 diabetes in terms of the effects of external vibration of the forearm on skin blood flow and the rate of NO production. Skin blood flow and NO production were measured before vibration, immediately after 5 min of vibration, and 5 min after vibration ceased. RESULTS Although externally applied vibration significantly increased skin blood flow for both groups (P = 0.0001), those with diabetes had significantly lower (223%; P = 0.003) skin blood flows compared to the healthy older adults (461%). The rate of NO production, expressed as microM NO . flux, also increased significantly in both groups after vibration (healthy group, 374%; diabetes group, 236%) and remained significantly elevated (healthy group, 258%; diabetes group, 177%) for at least 5 min; however, the difference between groups was not significant (P = 0.12). CONCLUSIONS These findings suggest that subjects with diabetes exhibit a lower skin blood flow and lower NO response to externally applied vibration than matched normal subjects.

Randomized Double-Blind Crossover Ondansetron-Dexamethasone versus Ondansetron-Placebo Study for the Treatment of Chemotherapy-Induced Nausea and Vomiting in Pediatric Patients with Malignancies

Purpose To determine whether the addition of dexamethasone to ondansetron (OND + DEX) is a more effective antiemetic regimen than ondansetron (OND) alone in children receiving chemotherapy. Patients and Methods Children who had solid tumors and who were receiving highly emetogenic chemotherapy, including cisplatin, carboplatin, cyclophosphamide, and ifosfamide, were randomized (1:1) in a double-blind fashion to receive either OND 0.15 mg/kg intravenously (i.v.) 30 min before and 4 and 8 h after chemotherapy and placebo, or OND + DEX (same OND doses plus DEX 8 mg/m2 i.v. 30 min before chemotherapy, followed by 16 mg/m2 in divided doses) as antiemetics. The patients were crossed over to the other antiemetic regimen when receiving an identical course of chemotherapy. Patients were monitored for emetic episodes, nausea, appetite, sense of well-being, and antiemetic adverse events. Results A total of 33 patients were evaluated. Sixty-one percent of the patients receiving OND + DEX regimens had a complete response for emetic episodes as compared with 23% with OND alone. Combined complete and major responses (two or less emetic episodes) were 86% for OND + DEX and 67% for OND. Failure for emetic episodes (more than five vomitings/day) were seen only in 7–10% of the total population. Minimal or no nausea was experienced in 74% of OND + DEX courses and in 52% of the OND courses. Appetite was better in OND + DEX courses (p = 0.006). Both antiemetic arms had similar adverse events. Mild to moderate sedation occurred in about half of the courses, followed by restlessness (20%), headache (17%), diarrhea (17%), and hiccups (2%). Conclusion The combination of ondansetron and dexamethasone is superior to ondansetron alone to control emetic episodes in children receiving highly emetogenic chemotherapy (p = 0.04).

Effects of Education on Return-to-Work Status for People With Fear-Avoidance Beliefs and Acute Low Back Pain

Background and Purpose: People with acute low back injury and fear-avoidance beliefs are at risk for remaining off work for an extended period of time. However, the effectiveness of intervention strategies for improving return-to-work status in people with acute low back pain and fear-avoidance beliefs has not been reported. The objective of this study was to determine whether education and counseling on pain management, physical activity, and exercise could significantly decrease the number of days that people with low back injury are off work. Subjects: Thirty-four people who were unable to return to work following a work-related episode of low back pain and who exhibited fear-avoidance beliefs participated in this study. Methods: Participants who scored 50 points or higher on the Fear-Avoidance Beliefs Questionnaire were alternately assigned to an education group or a comparison group. Both groups received conventional physical therapy intervention. Participants in the education group were given education and counseling on pain management tactics and the value of physical activity and exercise. The effectiveness of the interventions was measured by the number of days before people returned to work without restrictions. Results: All participants in the education group returned to regular work duties within 45 days. One third of the participants in the comparison group remained off work at 45 days. There was a statistically significant difference between the groups with regard to the number of days before returning to work. Discussion and Conclusion: Education and counseling regarding pain management, physical activity, and exercise can reduce the number of days off work in people with fear-avoidance beliefs and acute low back pain.

Quantitative measures of laryngeal function following teflon® injection or thyroplasty type I

Laryngeal/voice function was evaluated in six patients with unilateral true vocal fold paralysis following treatment with Teflon® injection (TEF) compared to six patients treated with thyroplasty type I (THY). Auditory perceptual, aerodynamic, and endoscopic assessments were conducted. Three judges rated nine voice characteristics. Aerodynamic measures included estimated subglottal pressure, airflow, and laryngeal resistance. Two judges rated laryngeal characteristics from flexible fiberoptic assessment. The THY group had significantly better voice quality and better quantitative aerodynamic findings compared to the TEF group. The TEF group also was more likely to have an irregular vocal fold edge, an irregular glottal closure pattern, a higher occurrence of hyperfunction and hypertrophy of the false vocal folds, edema, and erythema of the paralyzed folds. Results suggest that THY was associated with more favorable measures of laryngeal/voice function than TEF. It is likely that the poorer perceptual, aerodynamic, and endoscopic findings associated with TEF injection may be due to violation of the true vocal fold cover, particularly increased true vocal fold mass and stiffness.

The effects of skin moisture and subcutaneous fat thickness on the ability of the skin to dissipate heat in young and old subjects, with and without diabetes, at three environmental room temperatures

The Pennes model predicts the ability of the skin to dissipate heat as a function of conductive heat transfer and blood flow. Conductive heat exchange may be affected by skin moisture and subcutaneous fat thickness, factors not considered by Pennes. In the present investigation, we sought to expand the Pennes model by examining subcutaneous fat and skin moisture as factors of heat dissipation and their effects on heat exchange and blood flow. Subjects who were older (O) (mean age 64.2+/-5.9 years, n=15), had diabetes (D) (mean age 62+/-5.9 years, mean duration 13.2+/-9.1 years, n=15), and were younger (Y) (mean age 25.7+/-2.9 years, n=15) participated. Thermisters were placed in an iron heat probe and on the skin to measure the change in skin temperature to create a thermal change index to demonstrate the ability of the skin to dissipate heat. The lower back had the thickest subcutaneous fat layer for all subjects, which contributed to higher skin temperatures than the foot and hand in response to local and global heat. There was a significant inverse correlation between skin moisture and skin temperature after 5s of heat application (r=-0.73, p<0.001) with O and D having significantly less skin moisture than Y (p<0.05). O and D had significantly increased skin temperatures in response to local heat, as compared to Y, in all global temperatures (p<0.05). Thus, the Pennes model may need to be adjusted to take into consideration aging, diabetes, skin moisture, and subcutaneous fat thickness.