Relationship between changes in regional cerebral blood volume and oxygenation and changes in cardiac output and systemic vascular resistance during spinal anesthesia in women undergoing cesarean section

Body Size, Cerebral Blood Flow, Ambient Temperature, and Relative Brain Temperatures in Newborn Infants under Incubator Care

Subtle changes in body temperature affect the outcomes of ill newborns. However, the temperature profile of neonatal brains remains largely unknown. In open-cot care, increased cerebral perfusion is correlated with higher superficial brain temperatures. This study investigated the dependence of brain temperature (relative to rectal temperature) on ambient temperature, body size, cerebral perfusion, and metabolism in infants receiving incubator care. Rectal, scalp, and brain temperatures, superior vena cava flow, and brain oxygenation were assessed using echocardiography, thermo-compensatory temperature monitoring, and near-infrared spectroscopy in 60 newborns. These infants had a mean postconceptional age of 36.9 (2.2) weeks and weighed 2348 (609) g at the time of evaluation. The ambient temperature was maintained at 30.0 (1.0) °C. A higher rectal temperature was associated with greater postconceptional age (p = 0.002), body weight (p < 0.001), and head circumference (p < 0.001). Relative scalp, superficial brain, and deep brain temperatures were associated with smaller head circumference (p < 0.001, p = 0.030, and p = 0.015, respectively) and superior vena cava flow (p = 0.002, p = 0.003, and p = 0.003, respectively). In infants receiving incubator care, larger head sizes and increased brain perfusion were associated with lower relative scalp and brain temperatures. When considered alongside previous reports, cerebral perfusion may contribute to maintaining stable cerebral tissue temperature against ambient temperature changes.

Effect of continuous spinal anesthesia on the hemodynamics of labor analgesia in hypertensive pregnant women: a comparative, randomized clinical trial

BACKGROUND

To observe the changes in hemodynamic, stress and inflammatory responses during labor and their labor outcomes after continuous spinal anesthesia labor analgesia for hypertensive pregnant women, and to evaluate whether the continuous spinal anesthesia had any advantages compared to continuous epidural analgesia for hypertensive pregnant women and their newborns.

METHODS

A total of 160 hypertensive pregnant women were selected and randomly divided into continuous spinal anesthesia analgesia group (CSA group) and continuous epidural analgesia group (EA group). Participant age, height, weight and gestational week were recorded; MAP, VAS score, CO and SVR were recorded after the onset of regular uterine contractions (T₀), 10 min after analgesia (T₁), 30 min (T₂), 60 min (T₃), when the uterine opening was complete (T₄) and when the fetus was delivered (T₅); the duration of the first stage of labor and the second stage of labor were recorded; the number of cases of treatment with oxytocin and antihypertensive therapy, mode of delivery, eclampsia and postpartum hemorrhage were counted; pregnant women Bromage scores were recorded at T₂. We also recorded neonatal weight, Apgar scores at 1, 5 and 10 min after birth; arterial blood gas analysis of the umbilical cord was performed in newborns; finally, TNF-α, IL-6, and cortisol in pregnant women venous blood were measured at T₀, T₅, and 24 h after delivery (T₇). The number of successful compressions and the total drug dosage administered by the analgesic pump were recorded for both groups.

RESULTS

The first stage of labor in CSA was longer than EA (P < 0.05); the MAP, VAS and SVR value in CSA were lower than EA group at T₁, T₃ and T₄ (P < 0.05); in contrast, the CO in CSA at T3 and T4 was higher than in EA (P < 0.05). The oxytocin was more often used whereas the antihypertensive drugs were less used in CSA as compared to EA. The level of TNF-α, IL-6, Cor in the CSA at T5 was lower than the EA group (P < 0.05), and the level of TNF-α in the CSA group at T7 was lower than the EA group (P < 0.05).

CONCLUSION

For pregnant women with hypertension during pregnancy, continuous spinal anesthesia labor analgesia has no significant effect on the final mode of delivery, but shows precise analgesic effect and stabilizes circulatory system, it is recommended to perform continuous spinal anesthesia early in labor for hypertensive pregnant women, which can effectively reduce the stress reaction.

TRIAL REGISTRATION

ChiCTR-INR-17012659. Date of registration: 13/09/2017.

Changes of cerebral oxygenation indices measured by near infrared time-resolved spectroscopy during spinal anesthesia for cesarean section: Simultaneous measurement with cerebral blood flow

AIM

To measure the changes in cerebral oxygenation indices by near infrared time-resolved spectroscopy and the cerebral blood flow simultaneously after spinal anesthesia for cesarean section.

METHODS

This prospective observational study was conducted for 25 pregnant women scheduled for elective cesarean section under spinal anesthesia. During a period of 15 min after spinal anesthesia, cerebral oxygenation (ScO₂ ), and the total cerebral hemoglobin concentration (tHb) were measured using near infrared time-resolved spectroscopy and mean cerebral blood flow velocity (Vm) was measured using transcranial Doppler ultrasonography. Next, in the women who had nausea during the observed period, we compared these values when nausea was detected with those when it was not.

RESULTS

Mean arterial pressure (MAP) decreased to around 60 mmHg (by 25% compared to the control) 6 min after spinal anesthesia. Compared to the control, ScO₂ decreased by about 3% after 6 min and then gradually increased. The tHb, which reflects cerebral blood volume started to decrease just after spinal anesthesia and this continued until 12 min (the decrease was about 12%). Vm decreased by about 7%. In the 14 women who had nausea, MAP, Vm, and ScO₂ values when nausea was detected were significantly lower than when it was not.

CONCLUSION

The changes in cerebral hemodynamics may be small after spinal anesthesia in ordinary cesarean section compared to the reduction of systemic arterial blood pressure. There might be greater decreases in cerebral blood flow and oxygenation when nausea occurred in the pregnant women who experienced it after spinal anesthesia.

The effect of baricity of intrathecal bupivacaine for elective cesarean delivery on maternal cardiac output: a randomized study

BACKGROUND

Hemodynamic instability during spinal anesthesia for cesarean delivery is associated with adverse maternal and fetal outcomes. Plain and hyperbaric bupivacaine are commonly used for cesarean delivery, however, their distinctive pharmacologic properties may affect maternal hemodynamic profiles differently. The aim of this study was to compare hemodynamic profiles using a suprasternal Doppler cardiac output (CO) monitor in healthy term parturients randomized to receive plain or hyperbaric bupivacaine for cesarean delivery.

METHODS

One hundred-and-sixty-eight healthy parturients scheduled for elective cesarean delivery were randomly assigned to receive 10.9 mg of intrathecal 0.5% plain or hyperbaric bupivacaine, both with 0.2 mg morphine. The primary outcome was CO change after spinal anesthesia. Secondary outcomes were the incidence of hypotension, vasopressor use, and conversion to general anesthesia.

RESULTS

The mean (±SD) CO at baseline, 1 min and 5 min after spinal anesthesia, and after placental delivery was 4.6 ± 1.2, 5.4 ± 1.3, 5.1 ± 1.4, and 6.4 ± 1.7 L/min in the plain bupivacaine, and 4.5 ± 1.1, 5.2 ± 1.3, 4.9 ± 1.3, and 6.2 ± 1.9 L/min in the hyperbaric bupivacaine group. There were no significant differences in CO, mean arterial pressure, or systemic vascular resistance. Incidences of hypotension, vasopressor and supplemental analgesic use, and conversion to general anesthesia, were not different between groups.

CONCLUSIONS

Cardiac output changes after plain or hyperbaric bupivacaine were not different in term parturients undergoing spinal anesthesia for cesarean delivery. Further studies comparing block quality and the rate of conversion to general anesthesia are required.

Comparison of general anesthesia with endotracheal intubation, combined spinal-epidural anesthesia, and general anesthesia with laryngeal mask airway and nerve block for intertrochanteric fracture surgeries in elderly patients: a retrospective cohort study

BACKGROUND

There is no consensus on the optimal anesthesia method for intertrochanteric fracture surgeries in elderly patients. Our study aimed to compare the hemodynamics and perioperative outcomes of general anesthesia with endotracheal intubation, combined spinal-epidural anesthesia, and general anesthesia with laryngeal mask airway (LMA) and nerve block for intertrochanteric fracture surgeries in elderly patients.

METHODS

This is a retrospective study of 75 patients aged > 60 years scheduled for intertrochanteric fracture surgeries with general anesthesia with intubation (n = 25), combined spinal-epidural anesthesia (n = 25), and general anesthesia with LMA and nerve block (n = 25). The intraoperative hemodynamics were recorded, and the maximum variation rate was calculated. Postoperative analgesic effect was evaluated using the visual analog scale (VAS). Postoperative cognitive status was assessed using the Mini-Mental State Exam (MMSE).

RESULTS

The maximum variation rate of intraoperative heart rate, systolic blood pressure, diastolic blood pressure differed significantly between the three groups (general anesthesia with intubation > combined spinal-epidural anesthesia > general anesthesia with LMA and nerve block). The VAS scores postoperative 2 h, 4 h, 6 h, and 8 h also differed significantly between the three groups (general anesthesia with intubation > combined spinal-epidural anesthesia > general anesthesia with LMA and nerve block). The VAS scores postoperative 24 h were significantly lower in the general anesthesia with LMA/nerve block group than the general anesthesia with intubation group and the combined spinal-epidural anesthesia group. The MMSE scores postoperative 15 min and 45 min differed significantly between the three groups (general anesthesia with intubation < combined spinal-epidural anesthesia < general anesthesia with LMA and nerve block). The MMSE scores postoperative 120 min in the general anesthesia with intubation group were the lowest among the three groups. There was no significant difference in the incidence of respiratory infection postoperative 24 h, 48 h, and 72 h between the three groups.

CONCLUSION

Compared to general anesthesia with intubation and combined spinal-epidural anesthesia, general anesthesia with LMA and nerve block had better postoperative analgesic effect and less disturbances on intraoperative hemodynamics and postoperative cognition for elderly patients undergoing intertrochanteric fracture surgeries.