Journal article
Observational study of changes in epidural pressure and elastance during epidural blood patch in obstetric patients
International journal of obstetric anesthesia, Vol.23(2), pp.144-150
05/2014
DOI: 10.1016/j.ijoa.2014.01.003
PMCID: PMC4536553
PMID: 24631062
Abstract
During an epidural blood patch, we inject blood until the patient describes mild back pressure, often leading to injection of more than 20 mL of blood. We undertook this study to measure the epidural pressures generated during an epidural blood patch and to identify the impact of volume on epidural elastance in obstetric patients.
This study was performed in postpartum patients who presented for an epidural blood patch with symptoms consistent with a postdural puncture headache. After identification of the epidural space using loss of resistance to air or saline, we measured static epidural pressure after each 5-mL injection of blood. Models were then fitted to the data and the epidural elastance and compliance calculated.
Eighteen blood patches were performed on 17 patients. The mean final volume injected was 18.9±7.8 mL [range 6-38 mL]. The mean final pressure generated was 13.1±13.4 mmHg [range 2-56 mmHg]. A curvilinear relationship existed between volume injected and pressure, which was described by two models: (1) pressure=0.0254×(mL injected)(2)+0.0297 mL, or (2) pressure=0.0679×mL(1.742). The value for r2 was approximately 0.57 for both models. We found no correlation between the final pressure generated and the success of the epidural blood patch.
We found a curvilinear relationship between the volume of blood injected during an epidural blood patch and the pressure generated in the epidural space. However, there was a large variation in both the volume of blood and the epidural pressure generated. The clinical importance of this finding is not known. A larger study would be required to demonstrate whether pressure is a predictor of success.
Details
- Title: Subtitle
- Observational study of changes in epidural pressure and elastance during epidural blood patch in obstetric patients
- Creators
- S D Pratt - Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA, USA. Electronic address: spratt@bidmc.harvard.eduD W Kaczka - Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA, USAP E Hess - Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Resource Type
- Journal article
- Publication Details
- International journal of obstetric anesthesia, Vol.23(2), pp.144-150
- DOI
- 10.1016/j.ijoa.2014.01.003
- PMID
- 24631062
- PMCID
- PMC4536553
- NLM abbreviation
- Int J Obstet Anesth
- ISSN
- 0959-289X
- eISSN
- 1532-3374
- Publisher
- Netherlands
- Grant note
- K08 HL089227 / NHLBI NIH HHS HL089227 / NHLBI NIH HHS
- Language
- English
- Date published
- 05/2014
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Anesthesia
- Record Identifier
- 9984006356102771
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