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Biomedical subjects

G W Simons

Publications and source records attributed to G W Simons.

26 records · Page 2Linked to original sources
PubMed1978

A standardized method for the radiographic evaluation of clubfeet.

A new standardized technique is presented for positioning patients for the radiographic evaluation of clubfeet. The main reasons for inadequacy of the usual techniques are inaccuracy in measurement, movement of the patient and improper positioning of the patient or X-ray equipment. Means are proposed to avoid or minimize these problems. The critical views are those taken immediately preoperatively to assess deformity combinations and those taken before wound closure to verify completeness of surgical correction. These films are taken with the patient asleep to eliminate movement. Unacceptable films which do not conform to the standard technique are rejected and new films obtained. The method has proven to be acceptably accurate.

Child, Preschool↗
PubMed1977

Analytical radiography of club feet.

A radiographic method is described for making the diagnosis of talo-navicular subluxation before ossification of the navicular bone occurs. Seven basic combinations of deformities are thought to occur in the club foot. Radiography before operation enables the surgeon to determine which of these combinations exists in a particular foot, and radiography during operation enables him to determine wheter or not all the existing deformities have been corrected, and therefore whether or not the operation must be extended.

Child↗
PubMedDate not supplied

Complexation versus hemodialysis to reduce elevated aminoglycoside serum concentrations.

Seven patients with acutely elevated aminoglycoside serum concentrations were studied comparing the effect of hemodialysis (n = 3) with removal by complexation using ticarcillin or carbenicillin (n = 4). Aminoglycoside serum half-life before intervention averaged 96 hours for the dialysis group and 67 hours for the complexation group. Ticarcillin was used for a minimum of 48 hours, while hemodialysis removal was estimated over 48 hours, which included two 4-hour dialysis periods. Aminoglycoside serum half-life was reduced to an average of 11 hours with hemodialysis, while with complexation using ticarcillin, it was reduced to 12 hours. During the 48-hour comparison period, complexation removed approximately 50% more aminoglycoside than did hemodialysis, primarily because the improved removal technique was sustained over the entire time. Complexation appears to be as effective as continuous hemodialysis in lowering excessive aminoglycoside serum concentrations. Complexation with ticarcillin can be more rapidly initiated, is less expensive and there is a low risk of adverse reactions. This method provides continued treatment of infections in patients with elevated serum concentrations and/or nephrotoxicity who require cessation of aminoglycoside therapy.

Aged↗
PubMedDate not supplied

Pharmacokinetics and extravascular penetration of aztreonam in patients with abdominal sepsis.

Patients with abdominal sepsis were enrolled in a clinical trial of aztreonam vs. tobramycin. All were given clindamycin concomitantly. The pharmacokinetics of aztreonam in 21 patients randomly assigned to receive treatment with aztreonam are reported. The mean age of these patients was 68 years; most had underlying disorders such as malnutrition and cardiac or pulmonary disease. Creatinine clearance (Clcr) ranged from 11.2 to 133.1 ml/min. The usual dose of aztreonam was 2.0 g every 8-12 hr. A single pharmacokinetic study was performed over one dosing interval after steady-state conditions were achieved. In approximately one-half of the patients, peritoneal fluid was collected during the interval between doses. Penetration of aztreonam, as expressed as the ratio of concentration in the peritoneal fluid to that in serum, was higher for aztreonam (0.95:1) than for tobramycin (0.46:1). The ratio of the concentration in peritoneal fluid to the minimum inhibitory concentration (MIC) of the infecting bacteria was also higher for aztreonam. Serum pharmacokinetic data were analyzed by both two-compartment and moment analysis. For both the steady-state volume of distribution (Vdss) and total body clearance (TBC), the values determined by both methods were highly correlated (r = .96, .99, respectively). Average values for Vdss and TBC were 0.28 liters/kg and 80 ml/min. TBC for aztreonam correlated strongly with CLcr and was described by the regression equation TBC = 1.1 (Clcr) + 1.6, r = .87, P less than .01.

Abdomen↗
PubMedDate not supplied

External rotational deformities in club feet.

External rotation of both a structural and functional nature occurs in the lower limb of some patients with club feet. These external rotational deformities are due to two unrecognized and untreated combined deformities within the hindfoot and mid-foot: hindfoot varus and talo-navicular subluxation. If allowed to persist, they will eventually produce external rotation above the level of the ankle. This results in a condition that may be named "The Medial Malalignment Syndrome."

Adolescent↗
PubMedDate not supplied

The diagnosis and treatment of deformity combinations in clubfeet.

Analytical radiography enables the surgeon to plan, carry out, and verify correction of the clubfoot once conservative treatment has reached a plateau. The method helps the surgeon to diagnose the presence of one of the 7 possible deformity combinations and choose the appropriate steps of the progressive surgical approach. The method allows the surgeon to ascertain whether he has achieved correction or whether he has achieved correction or whether the next step in the progressive approach is required. Finally, because it is possible to determine the results of surgery with this method, the incidence of recurrent clubfeet may be considerably reduced. To obtain intra-operative films requires a minimal increase in operative time and greatly increases the probability of full correction with only a single operative intervention.

Clubfoot↗