Hyperbaric bupi on shortage. Considering isobaric bupi or tetracaine for single shot spinal for c section. Anybody else been in this situation of drug shortage and what did you do?
Sent from my iPhone using
SDN mobile
The work of Carvalho et al “The ED50 and ED95 of Intrathecal Isobaric Bupivacaine with Opioids for Cesarean Delivery, Anesthesiology 2005; 103:606 –12”.
In summary, Isobaric intrathecal bupivacaine when coadministered with intrathecal fentanyl (10 micrograms) and morphine (200 micrograms) for cesarean delivery had a ED95 values of 13.0 mg.
Here are some key points if your in a hurry and don't want to read the article:
- Isobaric solutions may also offer additional benefits when blocks are performed in the sitting position and there is potential for delay in assuming the horizontal position such as in cesarean sections.
- The mean duration of surgery was 62 minutes.
- Overall anesthetic success was reliable and similar to hyperbaric bupivacaine, with no failures in patients receiving doses in excess of 10 mg.
- With the addition of intrathecal opioids coupled with the lower cerebrospinal fluid specific gravity in pregnancy, we would expect isobaric bupivacaine to be hypobaric with respect to the patient’s cerebrospinal fluid. Spinal administration with patients in the sitting position wouldhave facilitated cephalad spread.
- In this study, they did not adjust doses of intrathecal bupivacaine to patient height or weight. Although some studies have suggested patient height and weight may affect block characteristics, other authors have demonstrated no effects of age, height, weight, or body mass index on the spread of sensory blockade.
- Norris et al. determined that adjusting the intrathecal dose for height and weight variables within the normal range is unnecessary.
- To make up the study groups’ doses, all patients received a total intrathecal volume of 3 mlcomposed of 0.6 ml opioid solution (fentanyl and morphine) combined with a variable volume of the isobaric bupivacaine (1–2.2 ml) and normal saline
- Although they do not believe that the addition of fentanyl (baricity of 0.99333 g/ml) and morphine (baricity of 0.99983 g/ml) would have significantly changed the baricity and/or behavior of these hypobaric solutions in cerebrospinal fluid, it is important to remember that the findings of this study are for isobaric bupivacaine with 10 micrograms fentanyl and 200 micrograms morphine. The use of different intrathecal opioids or different fentanyl or morphine doses may result in slightly different ED50 and ED95 values.
Here are some other references for isobaric 0.5 being used for c-sections:
1. Ben-David B, Miller G, Gavriel R, Gurevitch A: Low-dose bupivacaine- fentanyl spinal anesthesia for cesarean delivery. Reg Anesth Pain Med 2000; 25:235–9
2. Sarvela PJ, Halonen PM, Korttila KT: Comparison of 9 mg of intrathecal plain and hyperbaric bupivacaine both with fentanyl for cesarean delivery. Anesth Analg 1999; 89:1257–62
3. Vercauteren MP, Coppejans HC, Hoffmann VL, Saldien V, Adriaensen HA: Small-dose hyperbaric versus plain bupivacaine during spinal anesthesia for cesarean section. Anesth Analg 1998; 86:989–93
4. Russell IF, Holmqvist EL: Subarachnoid analgesia for caesarean section: A double-blind comparison of plain and hyperbaric 0.5% bupivacaine. Br J Anaesth 1987; 59:347–53
5. Stienstra R, van Poorten JF: Plain or hyperbaric bupivacaine for spinal anesthesia. Anesth Analg 1987; 66:171–6
6. Critchley LA, Morley AP, Derrick J: The influence of baricity on the haemo- dynamic effects of intrathecal bupivacaine 0.5%. Anaesthesia 1999; 54:469–74
.
