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Michael M Todd

Publications and source records attributed to Michael M Todd.

13 recordsLinked to original sources
PubMed2006

Effects of intraoperative hypothermia on neuropsychological outcomes after intracranial aneurysm surgery.

OBJECTIVE: Subarachnoid hemorrhage and surgical obliteration of ruptured intracranial aneurysms are frequently associated with neurological and neuropsychological abnormalities. We reported that intraoperative cooling did not improve neurological outcome in good-grade surgical subarachnoid hemorrhage patients, as assessed by the Glasgow Outcome Scale score or other neurological and functional measures (National Institutes of Health Stroke Scale, Rankin Disability Scale, Barthel Activities of Daily Living). We now report the results of neuropsychological testing in these patients. METHODS: A total of 1,001 patients who bled < or = 14 days before surgery were randomly assigned to intraoperative hypothermia (t = 33 degrees C) or normothermia (37 degrees C). Outcome was assessed approximately 3 months after surgery. Patients underwent the Benton Visual Retention, Controlled Oral Word Association, Rey-Osterrieth Complex Figure, Grooved Pegboard, and the Trail Making tests. T-scores for each test were calculated from normative data. T-scores were averaged to calculate a Composite Score. A test result (or the Composite Score) was considered "impaired" if the T-score was two or more standard deviations below the norm. A Mini-Mental State Examination was also performed. RESULTS: Neurological outcome data were available in 1,000 patients. Sixty-one patients died. Of the 939 survivors, 873 completed 3 or more tests (exclusive of the Mini-Mental State Examination). Patients with poor neurological outcomes were less likely to complete testing; only 3.9% of Good Outcome (Glasgow Outcome Scale score = 1) patients were untested, compared with 38.6% of patients with Glasgow Outcome Scale scores of 3 and 4. There were no prerandomization demographic differences between the two treatment groups. For hypothermic patients, 16.8% were impaired from their Composite Score versus 20.0% of patients in the normothermic group (p = 0.317). For patients in the hypothermic group, 54.5% were impaired on at least one test, compared with 55.5% of patients in the normothermic group (p = 0.865). Similar results were seen in patients with baseline WFNS scores = I. Mini-Mental State Examination scores in the hypothermic and normothermic groups were 27.4 +/- 3.8 and 26.8 +/- 4.5, respectively. INTERPRETATION: This is the largest prospective evaluation of neuropsychological function after subarachnoid hemorrhage to date. Testing was completed in a high fraction of patients, demonstrating the feasibility of such testing in a large trial. However, the frequent inability to complete testing in poor-outcome patients suggests that testing may be best used to refine outcome assessments in good-grade patients. Many patients showed impairment on at least one test, with global impairment present in 17 to 20% of patients (18-21% of survivors). This was true even among the patients with the best preoperative condition (WFNS = 1). There was no difference in the incidence of impairment between hypothermic and normothermic groups.

Aged↗
PubMed2006

Influence of mannitol and furosemide, alone and in combination, on brain water content after fluid percussion injury.

BACKGROUND: Furosemide and mannitol are used to reduce intracranial pressure, but the impact of furosemide on edema of injured brain is unclear. The authors examined the effects of furosemide and mannitol, alone and in combination, on brain water content in brain-injured rats. METHODS: Anesthetized rats were subjected to a 2.2-atm left hemispheric fluid percussion injury. Two and three-quarters hours later, animals received 0.5, 1, 4, or 8 g/kg mannitol; 8 mg/kg furosemide; a combination of 4 g/kg mannitol plus 4 mg/kg furosemide; or 8 g/kg mannitol plus 8 mg/kg furosemide. One hour later (4 h after injury), plasma osmolality was measured, and hemispheric water content was determined by drying. Other animals were subjected to injury without drug treatment (impact only) or did not undergo injury (control). Pairwise group comparisons regarding the effects of mannitol and furosemide were restricted to only four groups: impact only, 8 g/kg mannitol, 8 mg/kg furosemide, and 8 g/kg mannitol plus 8 mg/kg furosemide. RESULTS: The water content of both hemispheres in the impact-only group was greater than in the control group (left greater than right). Mannitol, 8 g/kg, increased osmolality from 306 +/- 4 to 351 +/- 6 mOsm/kg (mean +/- SD) and reduced water content in the left hemisphere from 80.06 +/- 0.84% (impact only) to 78.24 +/- 0.73%. Furosemide, 8 mg/kg, had no effect on osmolality or water content. Brain water in animals treated with 8 g/kg mannitol plus 8 mg/kg furosemide did not differ from that seen with 8 g/kg mannitol alone. CONCLUSIONS: Mannitol increased plasma osmolality and reduced water content of the injured and contralateral hemispheres, whereas the authors observed no effect of furosemide when given either alone or in combination with mannitol.

Animals↗
PubMed2005

Increased incidence of melanoma in renal transplantation recipients.

BACKGROUND: It is well established that the incidence of nonmelanoma skin carcinoma is increased in renal transplantation recipients. However, existing studies are not in agreement over whether patients who undergo transplantation have an increased risk of melanoma. The objective of this study was to estimate the risk of melanoma among immunosuppressed renal transplantation recipients and to determine whether that risk is associated with patient and transplantation characteristics. METHODS: The authors studied 89,786 patients who underwent renal transplantation between 1988 and 1998 using the United States Renal Data System. Age standardized (to the United States 2000 population) incidence rates for melanoma were computed as diagnoses per 100,000 population and were compared with rates from the Surveillance, Epidemiology, and End Results (SEER) data. Incidence rates also were stratified to examine differences by age and gender. RESULTS: Of the 89,786 patients who underwent transplantation, 246 patients developed melanoma. The age-adjusted incidence rate of melanoma among renal transplantation recipients was 55.9 diagnoses per 100,000 population. This represented an increase in age-adjusted, standardized risk that was 3.6 times greater than the SEER population. Stratified analysis suggested that the risk of melanoma accelerated in male transplantation recipients as age increased, but the risk leveled off with age among female transplantation recipients. Finally, there was a trend for patients who experienced at least 1 acute rejection episode to develop melanoma (odds ratio = 1.34; P = 0.059). CONCLUSIONS: Renal transplantation recipients were nearly 3.6 times more likely to develop melanoma than the general population. Physicians who care for renal transplantation recipients should be vigilant in screening for melanoma.

Adult↗
PubMed2005

Mild intraoperative hypothermia during surgery for intracranial aneurysm.

BACKGROUND: Surgery for intracranial aneurysm often results in postoperative neurologic deficits. We conducted a randomized trial at 30 centers to determine whether intraoperative cooling during open craniotomy would improve the outcome among patients with acute aneurysmal subarachnoid hemorrhage. METHODS: A total of 1001 patients with a preoperative World Federation of Neurological Surgeons score of I, II, or III ("good-grade patients"), who had had a subarachnoid hemorrhage no more than 14 days before planned surgical aneurysm clipping, were randomly assigned to intraoperative hypothermia (target temperature, 33 degrees C, with the use of surface cooling techniques) or normothermia (target temperature, 36.5 degrees C). Patients were followed closely postoperatively and examined approximately 90 days after surgery, at which time a Glasgow Outcome Score was assigned. RESULTS: There were no significant differences between the group assigned to intraoperative hypothermia and the group assigned to normothermia in the duration of stay in the intensive care unit, the total length of hospitalization, the rates of death at follow-up (6 percent in both groups), or the destination at discharge (home or another hospital, among surviving patients). At the final follow-up, 329 of 499 patients in the hypothermia group had a Glasgow Outcome Score of 1 (good outcome), as compared with 314 of 501 patients in the normothermia group (66 percent vs. 63 percent; odds ratio, 1.14; 95 percent confidence interval, 0.88 to 1.48; P=0.32). Postoperative bacteremia was more common in the hypothermia group than in the normothermia group (5 percent vs. 3 percent, P=0.05). CONCLUSIONS: Intraoperative hypothermia did not improve the neurologic outcome after craniotomy among good-grade patients with aneurysmal subarachnoid hemorrhage.

Bacteremia↗
PubMed2005

A lesson learned.

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Ambulatory Surgical Procedures↗
PubMed2005

Rapid toluidine blue stain for Mohs' micrographic surgery.

BACKGROUND: Toluidine blue is a useful stain for detecting basal cell carcinoma during Mohs' micrographic surgery. OBJECTIVE: To demonstrate the efficacy of alkalinization on the toluidine blue stain. METHODS: A 1% aqueous toluidine blue-1% aqueous sodium borate solution was used to stain microscope slides for basal cell carcinoma during Mohs' micrographic surgery. RESULTS: Total toluidine blue staining time was reduced to less than 2.5 minutes, without compromising the quality of the stain. CONCLUSIONS: The rapid toluidine blue stain reduces staining time while maintaining staining quality, including the advantages specific to the toluidine blue stain.

Basal Cell Carcinoma↗
PubMed2002

Dermatologic surgery training in residency.

BACKGROUND: Dermatologic surgery is an integral part of dermatology residency training. OBJECTIVE: To characterize the current level of surgical training in dermatology residency programs. METHODS: A survey was mailed to the 112 dermatology residency programs in North America and Puerto Rico. RESULTS: A total of 71 residency programs (63%) responded. All programs offer training in surgical excisions, 97% of programs train residents in at least one cosmetic procedure, 92% of programs offer Mohs micrographic surgery, and 90% of programs train their residents in laser surgery. CONCLUSION: Surgical training in dermatology residency varies widely, with a trend toward more cosmetic procedures when compared with prior studies.

Dermatology↗
PubMed2002

Effect of mannitol and furosemide on plasma osmolality and brain water.

BACKGROUND: Mannitol and furosemide are used to reduce increased intracranial pressure (ICP) and to reduce brain bulk during neurosurgery. One mechanism by which these changes might occur is via a reduction in brain water content. Although mannitol and furosemide are commonly used in combination, there has been no formal evaluation of the interactive effects of these two drugs on brain water. The effect of mannitol and furosemide alone and in combination on water content of normal rat brain was examined. METHODS: The lungs of rats anesthetized with halothane were mechanically ventilated to maintain normal physiologic parameters. After baseline measurement of plasma osmolality, mannitol (1, 4, or 8 g/kg), furosemide (2, 4, or 8 mg/kg), or a combination of furosemide (8 mg/kg) and mannitol (1, 4, or 8 g/kg) was administered intravenously over approximately 15 min. One hour later, plasma osmolality was measured, the animals were killed, and brain water content was determined by wet and dry weight measurements. RESULTS: Mannitol produced a dose-dependent increase in plasma osmolality and reduction of brain water content. There was a linear relation between plasma osmolality and brain water content. Furosemide alone did not affect plasma osmolality or brain water at any dose. The combination of furosemide with mannitol resulted in a greater increase in plasma osmolality than seen with mannitol alone and a greater decrease in brain water at 4 and 8 g/kg of mannitol. CONCLUSIONS: The doses of mannitol and furosemide utilized were much larger than clinically applicable doses and were selected to maximize the ability to detect effect on brain water. The combination of mannitol and furosemide resulted in greater reduction of brain water content than did mannitol alone. Furosemide enhanced the effect of mannitol on plasma osmolality, resulting in a greater reduction of brain water content. Potential interaction (if any) of smaller, clinically used doses of mannitol and furosemide cannot be surmised from the current study.

Animals↗
PubMedDate not supplied

A lesson learned.

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Ambulatory Surgical Procedures↗