Equation to estimate body weight in elderly Mexican women using anthropometric measurements.

INTRODUCTION: Body weight is useful for many medical and nutritional procedures. When it is difficult or impossible to measure body weight in hospitalized/institutionalized elderly, it can be estimated through equations based on anthropometry generated in other countries, although their validity in other contexts has been poorly studied. OBJECTIVES: To create and validate an equation for estimating body weight for both, hospitalized and nursing home residents Mexican elderly women (institutionalized) using anthropometric measurements. METHODS: A validation study was carried out in elderly women (> or = 60 years old), admitted to the Geriatrics Service of the Hospital Civil de Guadalajara "Fray Antonio Alcalde" during February-April 19th (n = 43) and April 20th-June 2005 (n = 29), and elderly women residing in three nursing homes in the Metropolitan Area of Guadalajara evaluated during June 2003-June 2004 (n = 23). Subjects were weighed using a scale which was adapted to their clinical situation and were anthropometrically assessed. In the first sample, we generated a new equation using multiple regression analyses. Then, the equation was validated in the other two samples. We also estimated weight using Chumlea's equations: in all samples, estimated and actual weights were compared between each other through a paired t-test. A p < 0.05 was considered as significant. RESULTS: Mean ages in each sample were: 84.3 +/- 7.3, 84.4 +/- 9.1, and 84.2 +/- 8.5 years, respectively. Mean actual weights were: 48.2 +/- 13.5, 48.1 +/- 10.1, and 55.0 +/- 12.3 kg, respectively. The resulting equation was: estimated weight = (1.599* knee height) +(1.135* mid arm circumference) + (0.735*calf circumference) + (0.621* tricipital skinfold thickness)-83.123 (R2 = 0.896, p < 0.001). In hospitalized women, there were no significant differences between estimated and actual weight (sample 1:D-0.02 +/- 4.3 kg, p = 0.976; sample 2: D-0.7 +/- 4.2 kg, p = 0.352). In female nursing homes residents (institutionalized women) weight was significantly overestimated (1.9 +/- 3.2 kg p < 0.01), but the mean difference was smaller than the ones found using Chumlea's equations. CONCLUSIONS: The developed equation predicted accurately hospitalized elderly women's body weight in our context. In institutionalized elderly women, weight was significantly overestimated. It would be useful to derive equations for different settings.uals who present normal body weight.

[Value of intravenous nitroglycerin in hypertension after extracorporeal circulation]. / Intérêt de la trinitrine intraveineuse dans l'hypertension artérielle après circulation extracorporelle.

The authors compare the haemodynamic effects of intravenous nitroglycerin (IV TNT) in 14 patients developing hypertension (mean blood pressure greater than 90 mmHg) and in seven normotensive patients (70 less than mean blood pressure less than 90 mmHg) after cardiac surgery with extracorporeal circulation (ECC). TNT was administered at doses of 0.5, 1, 2 microgram.kg-1.min-1 then 2 microgram.kg-1.min-1 with the association of vascular filling in order to restore right and left arterial pressures to their initial values. Various haemodynamic parameters were measured or calculated. The results obtained: in the hypertensive patients, at the low dose (0.5 microgram.kg-1.min-1) a prevalent venodilatory action was noted: RAP: 7.64 +/- 2.76 p less than 0.05; LAP: 9.07 +/- 3.19 p less than 0.05; at the middle dose (1 microgram.mg-1.min-1) venodilation continued resulting in a fall in BP 95.28 +/- 26.11 p less than 0.01 and above all in Cl: 2.28 +/- 0.36 p less than 0.01; at the maximum dose used, the action of TNT affected both the venous and arteriolar sector causing a major fall in BP: 89.64 +/- 23.88 p less than 0.001, in Cl: 2.29 +/- 0.33 p less than 0.01 and above all RVSI: 19.94 +/- 6.24 p less than 0.05. The association of vascular filling led to an increase in RAP and LAP (p = NS), Cl (p = NS) whilst BP remained low: 92.78 +/- 17.56 p less than 0.001 and also RVSI: 18.12 +/- 4.44 p less than 0.01. In the normotensive patients the administration of TNT, whatever the dose used, did not cause any significant changes (p = NS). In conclusion, the authors emphasise the value of the use of TNT in postoperative hypertensive states, in particular when associated with myocardial ischaemia.

[Effect of intravenous nytroglicerin in hypertensive patients during and after open heart surgery (author's transl)]. / Impiego della trinitrina intravenosa nel trattamento dell'ipertensione peri-operatoria nel paziente operato in circolazione extra-corporea.

The present study was performed to compare hemodynamic effect of intravenous Nitroglycerin (TNT i.v.) in 14 patients developing acute hypertension (Group I) and in 7 non hypertensives after open heart surgery (Group II). In all patients, m.a. 56.6 yrs, (10 mitral and/or aortic prosthetic valve replacements, 9 aorto-coronary bypass, 1 open mitral commissurotomy, 1 closure of atrial septal defect) TNT was infused at doses of 0.5, 1, 2 microgram X kg X min. and subsequently at 2 microgram X kg X min. after volume administration (2 + V.A.) to maintain right and left atrial pressure the same as control (P = N.S.). Mean arterial, right and left atrial pressures (MAP, RAP, LAP), cardiac frequency and index (CF, CI and systemic vascular resistance index (SVRI) were monitorized. TNT i.v. resulted in hypertensive patients (Group I) in reduction vs. control of: a) RAP (--20.17%) and LAP (--20.58%) at 0.5 microgram X kg X min. b) RAP (--26.13%), LAP (--27.50%), MAP (--19.94%) and CI (--12.98%) at 1 microgram X kg X X min. c) RAP (--22.47%), LAP (--26.89%), MAP (--24.68%), CI (--12.6%) and SVRI (--17.34%) at 2 microgram X kg X min. When RAP and LAP was maintained by volume administration TNT i.v. (2 microgram X kg X min.) resulted in an even greater increase in CI and a greater decrease in MAP and SVRI ((--22.04% and --24.88% respectively). No significant hemodynamic modification (P less than or equal to 0.05) were observed in non hypertensive patients (Group II) at all doses of TNT i.v. The results confirm a predominant venodilator effect of TNT at low doses and a good effect on arterial resistances at high doses in hypertensive patients. In view of previous reports of differing effects on ischemia TNT i.v. may be preferable to other vasodilator drugs for control of acute post-ECG hypertension, only on condition to maintain an adequate left ventricular filling pressure to prevent a fall of cardiac index. Moreover the absence of significant (P less than or equal to 0.05) hemodynamic modifications in non hypertensive patients may be a further advantage in the treatment of myocardial ischemia with i.v. TNT.