Carta al Editor

José Ricardo Navarro V.*

* Profesor Asociado Departamento de Cirugía Universidad Nacional de Colombia. Correspondencia: Carrera. 30 No. 45-03, Facultad de Medicina. Of. 205. Bogotá, Colombia. Correo electrónico: jrnavarrov@unal.edu.co

The following are considerations in response to the paper by Jorge Andrés Rubio Romero (1):

The average length of care for labor in patients in the active phase at Instituto Materno Infantil is six hours. Whenever a C-section or a Pomeroy procedure is scheduled, solid food intake is restricted for a 6-hour period, the patients receive a crystalloid infusion at a rate of 100 ml/hr and, during regional subarachnoid anesthesia, a 1000 ml ”co-loading” fluid protocol is initiated.

Hemodynamic changes in ASA 1-2 patients depend on the characteristics of the sympathetic nerve block: anesthetic level, patient positioning, administration rate, mass, temperature and site of application, and even the inter-individual variation (2). These changes are usually well tolerated by the patients.

Systemic changes (resistance, blood pressure, cardiac output) usually revert within 2-24 weeks post-partum(3). Likewise, sensitivity to local anesthetics remains high until the third day after delivery. The sensitivity level obtained for all the patients in the study was T4 (4).

The rate of injection of the local anesthetic in the subarachnoid space as a determining factor for hypotension in C-section (or post-partum Pomeroy) is still a matter for debate (2).

Additional prospective studies including a larger number of patients and that control the various confounding factors are required in order to establish a stronger association between the suggested hypothesis and hypotension.

1. Rubio JA. Hipotensión en anestesia regional y velocidad de inyección. Rev. Colomb. Anestesiol 2011;39 (4):508-512.

2. Simon L, Boulay G, Ziane F, Noblesse E, Mathiot J, Toubas M, et al. Effect of injection rate on hypotension associated with spinal anesthesia for cesarean section. International Journal Obstetric Anesthesia 2000;9:10-14.

3. Robson SC, Hunter S, Moore N, Dunlop W. Haemodynamic changes during the puerperium. A Doppler and M mode echocardiographic study. Br J Obstet Gynaecol 1987;94:1028-39.

4. Hoyos DC, Navarro JR, Eslava-Schmalbach J. Anestesia regional subaracnoidea para cesárea y Pomeroy postparto. Aplicación de anestésico local a una velocidad de inyección menor o mayor a 60 segundos. Rev. Colomb. Anestesiol. 2011;39:341-50.