Combined Colloid Preload and Crystalloid Coload Versus Crystalloid Coload During Spinal Anesthesia for Cesarean Delivery

Left ventricular end-diastolic pressure response to spinal anaesthesia in euvolaemic vascular surgery patients

PURPOSE

Regional anaesthesia techniques provide highly effective alternative to general anaesthesia. Existing evidence on the effect of spinal anaesthesia (SA) on cardiac diastolic function is scarce. This study aimed to evaluate the effects of a single-injection, low-dose SA on left ventricular end-diastolic pressures (LVEDP) using echocardiography in euvolaemic patients undergoing elective vascular surgery.

METHODS

This is a prospective study in adult patients undergoing elective vascular surgery with SA. Patients with contraindications for SA or significant valvular disease were excluded. During patients' evaluations fluid administration was targeted using arterial waveform monitoring. All patients underwent echocardiographic studies before and after SA for the assessment of indices reflective of diastolic function. LVEDP was evaluated using the E/e' ratio. Blood samples were drawn to measure troponin and brain natriuretic peptide (BNP) levels before and after SA.

RESULTS

A total of 62 patients (88.7% males, 71.00 ± 9.42 years) were included in the analysis. In total population, end-diastolic volume (EDV, 147.51 ± 41.36 vs 141.72 ± 40.13 ml; p = 0.044), end-systolic volume (ESV, 69.50 [51.50] vs 65.00 [29.50] ml; p < 0.001) and E/e' ratio significantly decreased (10.80 [4.21] vs. 9.55 [3.91]; p = 0.019). In patients with elevated compared to those with normal LVEDP, an overall improvement in diastolic function was noted. The A increased (- 6.58 ± 11.12 vs. 6.46 ± 16.10; p < 0.001) and E/A decreased (0.02 ± 0.21 vs. - 0.36 ± 0.90; p = 0.004) only in the elevated LVEDP group. Patients with elevated LVEDP had a greater decrease in E/e' compared to those with normal LVEDP (- 0.03 ± 2.39 vs. - 2.27 ± 2.92; p = 0.002).

CONCLUSION

This study in euvolaemic patients undergoing elective vascular surgery provides evidence that SA improved LVEDP.

Up-and-down determination of prophylactic norepinephrine boluses combined with crystalloid co-load for preventing post-spinal anesthesia hypotension during cesarean section

BACKGROUND

The use of a fluid co-load has been shown to enhance hemodynamic stability and diminish the occurrence of hypotension after spinal anesthesia when paired with prophylactic norepinephrine. This research aimed to identify the effective dosages (ED90 and ED50) of prophylactic norepinephrine boluses, in conjunction with a crystalloid co-load, for the prevention of hypotension after spinal anesthesia in cesarean delivery patients.

METHODS

Patients were administered crystalloid co-loads at a dosage of 10 mL/kg, in addition to preventive norepinephrine dosages direct following spinal anesthesia administration. The dosages of norepinephrine were established employing the up-and-down sequential allocation technique, starting with 8 µg and progressively rising by 1 µg increments. The primary objective was to detect the effective dosage (ED90 and ED50) of norepinephrine necessary to avoid hypotension following spinal anesthesia.

RESULTS

The ED90 for a single norepinephrine bolus, in combination with a crystalloid co-load, was calculated to be 5.35 µg (95% CI: 4.75 to 7.13). The ED50 was determined to be 4.05 µg (95% CI: 3.68 to 4.46) using the up-and-down method and 3.926 µg (95% CI: 3.362 to 4.422) through the probit regression model.

CONCLUSION

A prophylactic norepinephrine bolus of 5.35 µg, administered with a crystalloid co-load, effectively prevents hypotension following the spinal anesthesia in cesarean delivery patients.

Comparison of crystalloid and colloid co-load combined with norepinephrine prophylaxis on post-spinal anesthesia hypotension during cesarean delivery: a randomized sequential allocation dose-finding study

Background

Fluid loading is an essential component of treatment for reducing the incidence of post-spinal anesthesia hypotension and is necessary to maintain intravascular volume, perfuse tissues, and control spinal anesthesia hypotension after sympathetic blockade. We performed a randomized sequential allocation dose-finding study to compare the effects of 10 mL/kg crystalloid and 6% hydroxyethyl starch (130/0.4) co-load on the ED90 of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery.

Methods

Eighty patients were randomly allocated to receive either a 10 mL/kg crystalloid (Crystalloid Group, n = 40) or 6% hydroxyethyl starch (130/0.4) (Colloid Group, n = 40) co-load combined with prophylactic norepinephrine infusion during spinal anesthesia for cesarean delivery. The first patient received an initial prophylactic norepinephrine infusion rate of 0.025 μg/kg/min. Subsequent patients received a 0.005 μg/kg/min gradient dose of prophylactic norepinephrine. This dose was administered as a gradient based on its effectiveness for preventing post-spinal anesthesia hypotension (defined as SBP < 80% of baseline value) and determined by the up-and-down sequential allocation methodology. The primary study outcome was the ED90 of prophylactic norepinephrine infusion. Secondary outcomes included the incidence of post-spinal anesthesia hypotension, bradycardia, hypertension, Apgar scores, and umbilical artery blood gas values were also measured.

Results

The ED90 values of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery were 0.063 μg (95% CI: 0.050 to 0.064) and 0.062 μg (95% CI: 0.045 to 0.064) using isotonic regression analysis, and 0.068 μg (95% CI: 0.056 to 0.353) and 0.060 μg (95% CI: 0.050 to 3.590) using probit regression analysis in the Crystalloid Group and Colloid Group, respectively. The secondary outcomes were comparable between the two groups.

Conclusion

The administration of a 10 mL/kg 6% hydroxyethyl starch (130/0.4) does not provide additional benefits compared to crystalloid co-load in reducing the ED90 of prophylactic norepinephrine infusion for preventing post-spinal anesthesia hypotension during cesarean delivery.

Subclavian vein ultrasound-guided fluid management to prevent post-spinal anesthetic hypotension during cesarean delivery: a randomized controlled trial

BACKGROUND

Hypotension frequently occurs after spinal anesthesia during cesarean delivery, and fluid loading is recommended for its prevention. We evaluated the efficacy of subclavian vein (SCV) ultrasound (US)-guided volume optimization in preventing hypotension after spinal anesthesia during cesarean delivery.

METHODS

This randomized controlled study included 80 consecutive full-term parturients scheduled for cesarean delivery under spinal anesthesia. The women were randomly divided into the SCVUS group, with SCVUS analysis before spinal anesthesia with SCVUS-guided volume management, and the control group without SCVUS assessment. The SCVUS group received 3 mL/kg crystalloid fluid challenges repeatedly within 3 min with a 1-min interval based on the SCV collapsibility index (SCVCI), while the control group received a fixed dose (10 mL/kg). Incidence of post-spinal anesthetic hypotension was the primary outcome. Total fluid volume, vasopressor dosage, changes in hemodynamic parameters, maternal adverse effects, and neonatal status were secondary outcomes.

RESULTS

The total fluid volume was significantly higher in the control group than in the SCVUS group (690 [650-757.5] vs. 160 [80-360] mL, p < 0.001), while the phenylephrine dose (0 [0-40] vs. 0 [0-30] µg, p = 0.276) and incidence of post-spinal anesthetic hypotension (65% vs. 60%, p = 0.950) were comparable between both the groups. The incidence of maternal adverse effects, including nausea/vomiting and bradycardia (12.5% vs. 17.5%, p = 0.531 and 7.5% vs. 5%, p = 1.00, respectively), and neonatal outcomes (Apgar scores) were comparable between the groups. SCVCI correlated with the amount of fluid administered (R = 0.885, p < 0.001).

CONCLUSIONS

SCVUS-guided volume management did not ameliorate post-spinal anesthetic hypotension but reduced the volume of the preload required before spinal anesthesia. Reducing preload volume did not increase the incidence of maternal and neonatal adverse effects nor did it increase the total vasopressor dose. Moreover, reducing preload volume could relieve the heart burden of parturients, which has high clinical significance.

CLINICAL TRIAL REGISTRATION

The trial was registered with the Chinese Clinical Trial Registry at chictr.org.cn (registration number, ChiCTR2100055050) on December 31, 2021.

Value of inferior vena cava diameter and inferior vena cava collapse index in the evaluation of peripartum volume: A prospective cohort study

OBJECTIVE

The maternal intravascular volume status assessed during and after gestation is valuable but challenging due to the influence of the substantial adaptive cardiovascular changes during pregnancy. The present study aimed to investigate the changes in the size of inferior vena cava (IVC) diameter and collapse index (IVC-CI) during perinatal delivery and whether it is affected by the change in intravascular volume during delivery.

STUDY DESIGN

A total of 31 full-term, singleton, and cephalic delivery women delivered by vagina with an estimated blood loss of >500 mL measured longitudinally between September 2019 and September 2020 in the Department of Obstetrics and Gynecology of The Third Hospital in China. The end-expiratory (IVCe) and end-inspiratory (IVCi) diameters of the inferior vena cava were measured at the first, second, and third stages of labor (T1, T2, and T3, respectively) and postpartum haemorrhage ≥500 mL (T4 and after rapid rehydration 500 mL (T5). The collapse index of IVC was calculated, and blood pressure and heart rate were measured.

RESULTS

IVCe and IVC-CI changed significantly in a volume-dependent manner during the perinatal period (T1-T5; P < 0.05). IVCe narrowed significantly with volume reduction (after postpartum hemorrhage) and widened significantly with volume increase (after volume resuscitation). IVC-CI increases significantly with decreased capacity and decreases significantly with increased capacity.

CONCLUSION

The width and collapse index of IVC reflect the circulatory volume changes during the parturient's perinatal period with postpartum hemorrhage.

Colloid coload versus crystalloid coload to prevent maternal hypotension in women receiving prophylactic phenylephrine infusion during caesarean delivery: a randomised controlled trial

BACKGROUND

The optimal fluid strategy to prevent maternal hypotension during caesarean delivery remains unclear. This study aim was to compare the incidence of post-spinal anaesthesia hypotension in women receiving either colloid or crystalloid coload in the setting of prophylactic phenylephrine infusion during caesarean delivery.

METHODS

Healthy mothers undergoing elective caesarean delivery under spinal anaesthesia were randomised to receive a rapid intravenous coload with 6% hydroxyethyl starch 130/0.4 10 mL/kg (colloid group) or balanced crystalloid solution (Plasma Solution A) 10 mL/kg (crystalloid group) during spinal anaesthesia. All women had a prophylactic phenylephrine infusion initiated at 25 μg/min immediately after the subarachnoid block and titrated to systolic blood pressure using a standardised protocol. The primary outcome was the incidence of hypotension (systolic blood pressure <80% of baseline) until delivery.

RESULTS

The incidence of hypotension was 50% in the colloid group and 62% in the crystalloid group (absolute difference, -12% [95% CI -33% to 9%]; relative risk, 0.8 [95% CI 0.56 to 1.14]; P=0.314). No significant difference between groups was found in the number of hypotensive episodes (median 0.5 [IQR 0 to 1] vs 1 [0 to 2], P=0.132) or phenylephrine dose (675 [IQR 425 to 975] μg vs 750 [625 to 950] μg, P=0.109). The incidence of severe hypotension, symptomatic hypotension, bradycardia, nausea, and the neonatal outcomes were not significantly different.

CONCLUSIONS

This study found no benefit of colloid coload compared with crystalloid coload for preventing maternal hypotension in the presence of prophylactic phenylephrine infusion during caesarean delivery.

Effects of colloid preload on the incidence of hypotension in spinal anesthesia for cesarean section: a systematic review and meta-analysis

Background:

Hypotension is a common complication caused by spinal anesthesia (SA), which may have adverse impacts on the condition of the parturient and fetus. Liquid infusion was found to be relatively effective for reducing the incidence of hypotension. However, the question of whether colloid preload can optimize hemodynamic variables in the cesarean section remains controversial. This study aims to determine the effects of colloid preload on the incidence of hypotension induced by SA in elective cesarean section.

Methods:

Related keywords were searched on PubMed, EMBASE, and Cochrane Library from inception dates to May 2020. Studies included were evaluated for eligibility and quality. The primary outcome was the intra-operative incidence of hypotension and severe hypotension. The secondary outcomes included the lowest intra-operative systolic blood pressure, the maximal intra-operative heart rate, the intra-operative needs of ephedrine and phenylephrine, the incidence of maternal nausea and/or vomiting, and neonatal outcomes (umbilical artery pH and Apgar scores). Apart from the above, RevMan 5.3 was used for the data analysis.

Results:

Altogether nine randomized controlled trials were included in the meta-analysis. There were no significant differences in the incidence of intra-operative hypotension, severe hypotension, or neonatal outcomes between the colloid preload group and control group, except for the umbilical artery pH.

Conclusion:

This meta-analysis suggests that colloid preload does not significantly reduce the incidence of hypotension associated with SA in elective cesarean section.

Effects of isothermic crystalloid coload on maternal hypotension and fetal outcomes during spinal anesthesia for cesarean section: A randomized controlled trial

OBJECTIVE

Spinal anesthesia induced hypotension (SAIH) is a common occurrence during spinal anesthesia for cesarean section resulting in perturbing effects on maternal and fetal outcomes. Previous studies conducted to attenuate SAIH focused on the timing of intravenous fluid infusion and demonstrated the superiority of coload strategy on traditional preload strategy but neither of them focused on the effect of the temperature of crystalloid infused on SAIH and fetal outcomes. The current study aimed to assess the effect of the temperature of the crystalloid infused with coload strategy on the incidence of SAIH and fetal outcomes.

MATERIALS AND METHODS

Seventy-six parturients were enrolled into the study and data of 60 parturients were analyzed. Patients were randomly assigned to receive crystalloid coload at room temperature (Group RT, n = 30) or warmed at 37 °C (Group W, n = 30). The incidence of hypotension, cumulative hypotension episodes, heart rate, core body temperature, ephedrine dose, and fetal outcomes were recorded.

RESULTS

There was no significant difference in the incidence of maternal hypotension, cumulative hypotension episodes, and ephedrine dose (p = 0,625, p = 0,871, p = 0,460 respectively). Umbilical arterial pH and fetal Apgar scores at first and fifth minutes were higher in Group W than in Group RT (p = 0.013, p = 0.006 and p = 0.045 respectively). One fetus in Group RT but none in Group W had umbilical arterial pH lower than seven. Fetal birth weight and rectal temperature measurements were comparable in both groups (p = 0.639 and p = 0.675 respectively). Demographic data, patient characteristics, and surgery data were comparable between groups.

CONCLUSIONS

Isothermic crystalloid coload strategy results in higher umbilical pH values and Apgar scores in parturients scheduled for cesarean section under spinal anesthesia.

Effects of Vasoactive Medications and Maternal Positioning During Cesarean Delivery on Maternal Hemodynamics and Neonatal Acid-Base Status

Maternal hemodynamics, positioning, and anesthesia technique for cesarean delivery influence neonatal acid-base balance; direct effects from drugs that cross the placenta also have an influence. Spinal anesthesia limits fetal exposure to depressant drugs and avoids maternal airway instrumentation, but is associated with hypotension. Hypotension may be prevented/treated with vasopressors and intravenous fluids. Current evidence supports phenylephrine as the first-line vasopressor. Fifteen degrees of lateral tilt during cesarean delivery has been advocated to relieve vena caval obstruction, but routine use may be unnecessary in healthy nonobese women having elective cesarean delivery if maternal blood pressure is maintained near baseline.