...EVERYTHING has a price tag! Labour Epidural Analgesia (LEA) complicates normal delivery if timing of start of epidural analgesia, dosing and combination of drug(s) are not thought well!
P.S. PLACEMENT of epidural catheter can be done early but the start of local anaesthetic dosing must be ONLY when there is cervical dilatation of at least 4 cm.
Instrumental delivery chance increases with higher concentration of local anaesthetics, which should be kept to the minimum (<0.125% Levobupivacaine with or without Fentanyl 2 ug/ml).
With low concentration epidural infusion, Caesarean section chance is minimal with odds ratio 1.03, implying that 3% likely than the non-epidural group. However, even with low concentration, chance of instrumental delivery is more than double compared to non-epidural group (odds ratio 2.11). But, there is better labour pain relief (odds ratio 0.1, implying 0.09% likely), though the second stage of labour gets prolonged by about 15 minutes on an average.
Caesarean section is a quick procedure, so better to just top up the labour epidural catheter with preferably Lignocaine rather than Bupivacaine, for quick onset. Generally, 8- 20 ml 2% (20 mg/ml) with adrenaline 1:2,00,000 (5 ug/ml). Of course, incremental doses of 3-5 ml and titrating with blood pressure response is better because each patient is different particularly with mitral stenosis.
Polypharmacy through any route should be avoided before cord clamping and oxygen must be started right in the labour room particularly when there is foetal distress; the foetus also gets oxygen.
Predetermined dose of Bupivacaine Heavy 0.5% must be kept low depending on the sitting height of the patient and the height of epidural block (usually 2.0 - 2.6 ml). Loss of Cold sensation goes up the chest faster by two dermatomal segments than loss of pin-prick sensation (corresponds to surgical anaesthesia). Loss of pin prick sensation must not go above T4 level (nipple line) because T1-T4 are cardiac accelerator nerves, which if blocked cause significant bradycardia (<50 beats/min).
Therefore, when loss of Cold sensation reaches T2 level, it means that the surgical anaesthesia level (loss of pin-prick sensation) has reached T4 level, lagging behind by two dermatomal segments. Thereupon, the trendelenberg position must be reversed to avoid high Spinal.
For rapid onset (<5 min compared to epidural >10 min) and adequate motor block, many prefer spinal block despite having epidural catheter in situ because failure rate with epidural is high (23.5% compared to spinal 2.7%). The spinal dose must be less and also trendelenberg tilt time must be strictly watched to avoid high spinal because the patient was already having epidural infusion. The choice of Bupivacaine Heavy (settles down within CSF) generally prevents high spinal unless trendelenberg tilt is allowed for too long! Generally, T6 level block (sub-xiphisternal) is enough.
LUMBAR lordosis sometimes does not allow upward spread. Trendelenberg tilt 20 degree or more for 40 seconds or more might be needed for the spread because the hyperbaric (8% dextrose added) mixture of Bupivacaine tends to settle down.
FIXATION of the drug occurs quickly. Therefore, the trendelenberg tilt must be done as quickly as possible after administration of the drug if higher spread at least to T6 (subxiphisternal) level is desired for Caesarean section. Even less dose volume can be enough when the tilt is applied. But, have to keep testing the level of block and have to be vigilant about the effect on blood pressure and heart rate - thereupon, the table is straightened!
The Effect of Trendelenburg Posture on Sensory Block Level in Spinal Anesthesia with Intrathecal Hyperbaric Bupivacaine for Hernia Repair:
https://www.researchgate.net/publication/278329952_The_Effect_of_Trendelenburg_Posture_on_Sensory_Block_Level_in_Spinal_Anesthesia_with_Intrathecal_Hyperbaric_Bupivacaine_for_Hernia_Repair
Spinal Anesthesia:
https://www.medbox.org/spinal-anesthesia-handout/download.pdf
A comparison of spinal and epidural anesthesia for cesarean section following epidural labor analgesia: A retrospective cohort study:
https://www.sciencedirect.com/science/article/pii/S1875459715000181
How to interpret odds ratios that are smaller than 1?
http://onbiostatistics.blogspot.com/2012/02/how-to-interpret-odds-ratios-that-are.html?m=1
Rates of caesarean section and instrumental vaginal delivery in nulliparous women after low concentration epidural infusions or opioid analgesia: systematic review:
https://www.bmj.com/content/328/7453/1410.full.print
Labor epidural analgesia: Past, present and future:
http://www.indianjpain.org/article.asp?issn=0970-5333;year=2014;volume=28;issue=2;spage=71;epage=81;aulast=Reena,
P.S. PLACEMENT of epidural catheter can be done early but the start of local anaesthetic dosing must be ONLY when there is cervical dilatation of at least 4 cm.
Instrumental delivery chance increases with higher concentration of local anaesthetics, which should be kept to the minimum (<0.125% Levobupivacaine with or without Fentanyl 2 ug/ml).
With low concentration epidural infusion, Caesarean section chance is minimal with odds ratio 1.03, implying that 3% likely than the non-epidural group. However, even with low concentration, chance of instrumental delivery is more than double compared to non-epidural group (odds ratio 2.11). But, there is better labour pain relief (odds ratio 0.1, implying 0.09% likely), though the second stage of labour gets prolonged by about 15 minutes on an average.
Caesarean section is a quick procedure, so better to just top up the labour epidural catheter with preferably Lignocaine rather than Bupivacaine, for quick onset. Generally, 8- 20 ml 2% (20 mg/ml) with adrenaline 1:2,00,000 (5 ug/ml). Of course, incremental doses of 3-5 ml and titrating with blood pressure response is better because each patient is different particularly with mitral stenosis.
Polypharmacy through any route should be avoided before cord clamping and oxygen must be started right in the labour room particularly when there is foetal distress; the foetus also gets oxygen.
Predetermined dose of Bupivacaine Heavy 0.5% must be kept low depending on the sitting height of the patient and the height of epidural block (usually 2.0 - 2.6 ml). Loss of Cold sensation goes up the chest faster by two dermatomal segments than loss of pin-prick sensation (corresponds to surgical anaesthesia). Loss of pin prick sensation must not go above T4 level (nipple line) because T1-T4 are cardiac accelerator nerves, which if blocked cause significant bradycardia (<50 beats/min).
Therefore, when loss of Cold sensation reaches T2 level, it means that the surgical anaesthesia level (loss of pin-prick sensation) has reached T4 level, lagging behind by two dermatomal segments. Thereupon, the trendelenberg position must be reversed to avoid high Spinal.
For rapid onset (<5 min compared to epidural >10 min) and adequate motor block, many prefer spinal block despite having epidural catheter in situ because failure rate with epidural is high (23.5% compared to spinal 2.7%). The spinal dose must be less and also trendelenberg tilt time must be strictly watched to avoid high spinal because the patient was already having epidural infusion. The choice of Bupivacaine Heavy (settles down within CSF) generally prevents high spinal unless trendelenberg tilt is allowed for too long! Generally, T6 level block (sub-xiphisternal) is enough.
LUMBAR lordosis sometimes does not allow upward spread. Trendelenberg tilt 20 degree or more for 40 seconds or more might be needed for the spread because the hyperbaric (8% dextrose added) mixture of Bupivacaine tends to settle down.
FIXATION of the drug occurs quickly. Therefore, the trendelenberg tilt must be done as quickly as possible after administration of the drug if higher spread at least to T6 (subxiphisternal) level is desired for Caesarean section. Even less dose volume can be enough when the tilt is applied. But, have to keep testing the level of block and have to be vigilant about the effect on blood pressure and heart rate - thereupon, the table is straightened!
The Effect of Trendelenburg Posture on Sensory Block Level in Spinal Anesthesia with Intrathecal Hyperbaric Bupivacaine for Hernia Repair:
https://www.researchgate.net/publication/278329952_The_Effect_of_Trendelenburg_Posture_on_Sensory_Block_Level_in_Spinal_Anesthesia_with_Intrathecal_Hyperbaric_Bupivacaine_for_Hernia_Repair
Spinal Anesthesia:
https://www.medbox.org/spinal-anesthesia-handout/download.pdf
A comparison of spinal and epidural anesthesia for cesarean section following epidural labor analgesia: A retrospective cohort study:
https://www.sciencedirect.com/science/article/pii/S1875459715000181
How to interpret odds ratios that are smaller than 1?
http://onbiostatistics.blogspot.com/2012/02/how-to-interpret-odds-ratios-that-are.html?m=1
Rates of caesarean section and instrumental vaginal delivery in nulliparous women after low concentration epidural infusions or opioid analgesia: systematic review:
https://www.bmj.com/content/328/7453/1410.full.print
Labor epidural analgesia: Past, present and future:
http://www.indianjpain.org/article.asp?issn=0970-5333;year=2014;volume=28;issue=2;spage=71;epage=81;aulast=Reena,
Comments
Post a Comment