Failed spinal anesthesia for cesarean delivery: prevention, identification and management

PURPOSE OF REVIEW

There is an increasing awareness of the significance of intraoperative pain during cesarean delivery. Failure of spinal anesthesia for cesarean delivery can occur preoperatively or intraoperatively. Testing of the neuraxial block can identify preoperative failure. Recognition of the risk of high neuraxial block in repeat spinal in case of preoperative failure is important.

RECENT FINDING

Knowledge of risk factors for block failure facilitates prevention by selecting the most appropriate neuraxial procedure, adequate intrathecal doses and choice of technique. Intraoperative pain is not uncommon, and neither obstetricians nor anesthesiologists can adequately identify intraoperative pain. Early intraoperative pain should be treated differently from pain towards the end of surgery.

SUMMARY

Block testing is crucial to identify preoperative failure of spinal anesthesia. Repeat neuraxial is possible but care must be taken with dosing. In this situation, switching to a combined spinal epidural or an epidural technique can be useful. Intraoperative pain must be acknowledged and adequately treated, including offering general anesthesia. Preoperative informed consent should include block failure and its management.

The 90% effective dose of intrathecal hyperbaric bupivacaine for Cesarean delivery under combined spinal-epidural anesthesia in parturients with super obesity: an up-down sequential allocation study

PURPOSE

To determine the 90% effective dose (ED90) of intrathecal hyperbaric bupivacaine for Cesarean delivery under combined spinal-epidural anesthesia (CSE) in parturients with super obesity (body mass index [BMI] ≥ 50 kg·m-2).

METHODS

We enrolled parturients with BMI ≥ 50 kg·m-2 with term, singleton vertex pregnancies undergoing elective Cesarean delivery under CSE. An independent statistician generated the 0.75% hyperbaric bupivacaine dosing regimen in increments of 0.75 mg using a biased-coin up-down sequential allocation technique. This was combined with 15 μg fentanyl, 150 μg morphine, and normal saline to a volume of 2.05 mL. The initial and maximum doses were 9.75 mg and 12 mg, respectively. Participants, clinical team, and outcome assessors were blinded to the dose. The primary outcome was block success, defined as T6 block to pinprick within ten minutes and no intraoperative analgesic supplementation within 90 min of spinal injection. We determined the ED90 using logistic regression.

RESULTS

We enrolled 45 parturients and included 42 in the analysis. All doses achieved a T6 level within ten minutes, and the primary outcome occurred in 0/1 (0%) of the 9.75-mg doses, 2/3 (67%) of the 10.5-mg doses, 21/27 (78%) of the 11.25-mg doses, and 11/11 (100%) of the 12-mg doses. The ED90 of hyperbaric bupivacaine was 11.56 mg (95% confidence interval, 11.16 to 11.99). Four parturients (9.5%) had sensory level higher than T2, but none was symptomatic or required general anesthesia.

CONCLUSION

The estimated ED90 of hyperbaric bupivacaine with fentanyl and morphine in parturients with super obesity undergoing Cesarean delivery under CSE was approximately 11.5 mg.

STUDY REGISTRATION

ClinicalTrials.gov (NCT03781388); first submitted 18 December 2018.

Efficacy and Ease of Use of a Newly Designed Pencil-Point Epidural Needle Compared to Conventional Tuohy Epidural Needle: A Randomized Single-Blind Pilot Study

Background and objective Accidental dural puncture (ADP) and consequent post-dural puncture headache (PDPH) related to epidural needle use have prompted the design of a pencil-point epidural needle. The aim of this prospective, randomized, single-blind pilot study was to assess the efficacy, ease of use, patient satisfaction, and adverse events associated with this newly designed pencil-point epidural needle compared to a Tuohy conventional epidural needle in parturients receiving combined spinal-epidural (CSE) anesthesia for labor. Methods After obtaining the Institutional Research Board approval, 100 parturients were randomized to receive CSE anesthesia with either the new pencil-point epidural needle (Gertie Marx, IMD Inc., Huntsville, UT) (P group) or Tuohy needle (T group). We documented patients' height, weight, loss of resistance (LOR), number of attempts required, onset time of spinal anesthesia, difficulties with insertion of spinal needle, difficulties with insertion of the epidural needle and catheter, duration of the procedure, overall satisfaction of the provider and patient, ADP, PDPH, paresthesia, and pain. Results There was no difference in body mass index (BMI), LOR, number of attempts, and onset time of spinal anesthetic between the study groups. Success in obtaining cerebrospinal fluid (CSF) on the first attempt was 50/51 (98%) in the T group vs. 44/49 (89.8%) in the P group (p=0.108). The need for subsequent epidural needle readjustment to obtain CSF was higher in the P group (16/49, 32.7%) vs. the T group (3/51, 5.9%, p<0.001). Success on the first attempt with epidural catheter threading was lower with the pencil-point epidural needle compared to the Tuohy needle (69% vs. 98%, p<0.001). The anesthesiologist switched from the assigned pencil-point epidural needle to the Tuohy needle due to technical difficulties in 8/49 (16.3%) cases. The duration of the procedure was longer in the P group (16.43 ±6.33 minutes) compared to the T group (11.49 ±1.87 minutes) (p<0.001). User satisfaction was lower in the P group compared to the T group (34.7% vs. 90.2%, p<0.001). Patient satisfaction was lower with the pencil-point epidural needle compared to the Tuohy needle (75.5% vs. 92.2%, p=0.03). There was no difference in complication rates from the CSE procedure between groups (pain, paresthesia, ADP, and PDPH). Conclusion In this pilot study, the use of the pencil-point epidural needle for CSE was associated with less successful epidural catheter placement as well as low user and patient satisfaction compared to the Tuohy epidural needle. Modifications in the pencil-point epidural needle design are needed to improve efficacy and enhance user acceptance before a larger study can be conducted to evaluate the rates of ADP and PDPH.

Complicated Neuraxial Anesthesia in a Patient With Tethered Spinal Cord

Spinal anesthesia is a common anesthetic used in many surgical procedures. Anatomical variations and diseases make this procedure require extra considerations. Extra care should be taken into consideration in the pre-anesthesia evaluation when neuraxial anesthesia is planned.

We present the case of a patient undergoing cesarean section for the arrest of labor, who had a complicated labor course due to unrecognized history of a tethered spinal cord leading to inadequate analgesia, requiring replacement of epidural analgesia and spinal anesthesia. Ultimately, the decision was made to proceed with general anesthesia due to the patient’s discomfort. Exhaustive chart review after surgery showed a past MRI with evidence of a tethered spinal cord.

Sub-Dural Haematoma After Accidental Dural Puncture During Labour Epidural Analgesia

Inadvertent dural puncture with subsequent post-dural puncture headache (PDPH) is the most typical complication of labour epidural analgesia. Subdural hematoma (SDH) is a rare but late neurological complication of this procedure. The intracranial hypotension created by the cerebrospinal fluid (CSF) leakage through the dural defect can lead to the rupture of the bridging veins to produce a subdural hematoma. A change in the character from postural to a non-postural headache is a warning sign of subdural hematoma. We describe a case of post-dural puncture headache followed by the development of cranial SDH in a patient who refused a blood patch and opted for conservative treatment. We conclude that a high index of suspicion must be maintained with a witnessed dural puncture or even without it but having persistent headache, to detect any severe complications like an intracranial subdural hematoma. An epidural blood patch is to be considered when the headache does not subside with conservative management. Early employment of MRI or CT head imaging studies should be considered to exclude, diagnose, or treat any serious complication without unnecessary delay.

The effect of combined spinal epidural versus epidural analgesia on fetal heart rate in laboring patients at risk for uteroplacental insufficiency

Background: The effects of neuraxial analgesia on fetal heart tracings have been studied in "healthy" pregnancies. Our objective was to compare the impact of intrapartum epidural analgesia (EA) versus combined spinal epidural analgesia (CSE) on fetal heart rate changes in pregnancies at risk for uteroplacental insufficiency (UPI).Methods: Singleton pregnancies diagnosed with chronic hypertension, gestational hypertension and/or preeclampsia, and/or fetal growth restriction (FGR) and receiving neuraxial analgesia intrapartum from 2012 to 2015 were studied retrospectively. The primary outcome was change in fetal heart rate (FHR) category following neuraxial analgesia. Manual review of all FHR tracings was performed and classified by the National Institute of Child Health and Human Development (NICHD) categories. Data collection included maternal demographics, blood pressure, uterine tachysystole, uterine hypertonus, mode of delivery, interventions for FHR abnormalities and neonatal outcomes.Results: Of laboring patients at risk for UPI, 110 patients received EA and 127 patients received CSE. The rate and change in FHR categories and abnormalities following neuraxial analgesia were the same in both groups. Both EA and CSE resulted in a significant increase in NICHD FHR category II, from 27.3 to 65.5% for EA and 20.9 to 64.3% for CSE. The occurrence of maternal hypotension, uterine tachysystole, interventions for FHR abnormalities, and uterine hypertonus following neuraxial analgesia was not found to be significantly different between the two groups. When compared to the EA group, CSE had a higher rate of NICU admission (29.5 versus 16.4%, p = .021).Conclusions: FHR category increased following both CSE and EA. The side effects of maternal hypotension and need for fetal interventions was not different between CSE and EA.

Changes in cardiac index during labour analgesia: A double-blind randomised controlled trial of epidural versus combined spinal epidural analgesia - A preliminary study

BACKGROUND AND AIMS

Combined spinal-epidural (CSE) analgesia for labour and delivery is occasionally associated with foetal bradycardia. Decreases in cardiac index (CI) and/or uterine hypertonia are implicated as possible aetiological factors. No study has evaluated CI changes following combined spinal analgesia for labour and delivery. This prospective, double-blind, randomised controlled trial evaluates haemodynamic trends during CSE and epidural analgesia for labour.

METHODS

Twenty-six parturients at term requesting labour analgesia were randomised to receive either epidural (E) or CSE analgesia. The Electrical Cardiometry Monitor ICON^® was used to continuously determine maternal CI non-invasively, heart rate (HR) and stroke volume at baseline and up to 60 min after initiation of either intrathecal or epidural analgesia. In addition, maternal systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded.

RESULTS

Both SBP and DBP had a similar, significant decrease following initiation of either epidural or CSE analgesia. However, parturients in the CSE group (n = 10) demonstrated a significant decrease in HR and CI compared to the baseline measurements. On the other hand, the parturients in the E (n = 13) group showed no decreases in either maternal HR or CI. Foetal heart changes were observed in four patients following CSE and one patient following an epidural.

CONCLUSION

Labour analgesia with CSE is associated with a significant decrease in HR and CI when compared to labour analgesia with epidural analgesia. Further studies are necessary to determine whether a decrease in CI diminishes placental blood flow.

Anaesthetic management of a case of dilated cardiomyopathy for emergency appendectomy

The anesthetic management of a patient with dilated cardiomyopathy (DCM) undergoing non-cardiac surgery poses a challenge for anesthesiologist either due to pre-existing or a risk of precipitating congestive heart failure. We report a successful use of combined spinal epidural for emergency appendicectomy in a patient of DCM. Different anesthetic concerns and agents, some recent advances are also discussed.

Anesthetic management of a patient with spinocerebellar degeneration

Spinocerebellar degeneration or olivopontocerebellar degeneration denotes a group of disorders of various etiologies manifesting as degenerative changes of various part of the central nervous system. We describe the anesthetic management of a patient with severe olivopontocerebellar degeneration posted for vaginal hysterectomy. A combined spinal epidural technique was performed at the level of L2-L3. The anesthetic implications of the various aspects of spinocerebellar degeneration are discussed.

Combined spinal epidural and epidural volume extension: Interaction of patient position and hyperbaric bupivacaine

BACKGROUND

Previous trials have documented failure of block augmentation with epidural volume extension, when applied after the intrathecal injection of hyperbaric bupivacaine was made in sitting position. However, there is no study comparing the effect of change in patient position during block performance, on the results of epidural volume extension.

MATERIALS AND METHODS

The study was conducted in two parts in American Society of Anesthesiologists physical status I or II parturients scheduled for elective cesarean section under regional anesthesia. In the first part, 28 patients were randomized to one of the two groups, depending on whether epidural volume extension was applied following the block in sitting (group SE) or lateral position (group LE) (n=14 each). In the second part of the study another 28 patients were recruited and randomized to receive the block in sitting (group S) or lateral (group L) position (n=14 each), without epidural volume extension. All patients received combined spinal epidural block using needle-through-needle technique with intrathecal injection of 9 mg hyperbaric bupivacaine (0.5%) and 10 μg fentanyl. Epidural volume extension was performed using 5 ml normal saline in groups SE and LE.

RESULTS

In the first part of the study, the maximum sensory block level was higher in group LE vs. SE (P<0.05). In the second part of the study, no significant difference was seen in the maximum sensory level between group S and group L (P>0.05).

CONCLUSIONS

If epidural volume extension is being applied with intention of rapid extension of sensory block when hyperbaric bupivacaine has been injected intrathecally, the combined spinal epidural block should be performed in lateral position rather than in the sitting position.

Case report and mini literature review: anesthetic management for severe peripartum cardiomyopathy complicated with preeclampsia using sufetanil in combined spinal epidural anesthesia

Peripartum cardiomyopathy (PPCM) is a rare entity, and anesthetic management for cesarean section of a patient with this condition can be challenging. We hereby present the anesthetic management of a patient with PPCM complicated with preeclampsia scheduled for cesarean section, along with a mini review of literature. A 24 year-old primigravida with twin gestation was admitted to our hospital with severe PPCM and preeclampsia for peripartum care, which finally required a cesarean section. Preoperative optimization was done according to the goal of managing left ventricular failure. Combined spinal epidural (CSE) anaesthesia with bupivacaine and sufentanil was used for cesarean section under optimal monitoring. The surgery was completed without event or complication. Postoperative pain relief was adequate and patient required only one epidural top up with sufentanil 6 hours after operation. To the best of our knowledge there is no report in literature of the use of sufentanil as a neuraxial opioid in the anesthetic management of cesarean section in a patient with PPCM. CSE with sufentanil may be a safer and more effective alternative in such cases.