Coload Group Research Articles

The Effect of Fluid Preloading on the Incidence of Hypotension During Spinal Anesthesia

Background: Small doses of local anaesthetic are injected into the CSF fluid in the subarachnoid region to produce spinal anaesthesia (SA). Aim: This paper was contributed to study the effect of fluid preloading on the incidence of hypotension during spinal anaesthesia. Patients and methods: This cross-sectional study recruited 45 patients in different hospitals in Iraq for a study that ranged from the 15th of June in the year 2021 to the 24th of August in the year 2022. This paper dealt with the study of the effect of fluid preload on the incidence of hypotension during spinal anaesthesia, as it included in the clinical characteristics’ tests related to mothers or women who underwent caesarean delivery under spinal anaesthesia. This study divided the collected data into two groups, one of which was the patient group, which included patients who underwent spinal anaesthesia, which this group is considered as the co-loading group, which included 23 patients out of the total number of patients' data collected, while it was represented by the preload group, which included women who underwent spinal anaesthesia, which included 22 patients out of the total number of patients. This paper was conducting and analysing the collected data by SPSS. Discussion: The difference was that when their systolic blood pressure fell to 90 mm Hg, they began using a vasopressor heavily. The current finding found the Apgar score of the co-load who patients group (8.91) was found higher that preload who control group (8.95%) within 5 min in compare 1 min. In the present analysis, there was also a statistically significant variation between the co-load (81.4%) and pre-load (45.3%) groups in terms of the incidence of hypotension. The incidence of hypotension was statistically significantly different between the preload (80%) as well as co-load (51%) groups, according to research through (Oh AY et al., 2014). Both trials revealed that the co-load group's blood pressure dramatically decreased. Conclusion: This study found that (45.3%) were within the preload group as a control group and (81.4%) in the co-load group as patients group had hypotension. Preloading was, therefore, more effective than co-loading in preventing spinal anesthesia-induced hypotension of cesarean section moms. It may not be essential to postpone surgery to provide a preload of liquids.

Comparison of Crystalloid Preloading and Coloading for Prevention of Spinal-induced Hypotension in Cesarean Delivery: A Randomized Controlled Trial at a Tertiary Facility in Ghana

BACKGROUND: Spinal anesthesia is the recommended technique for cesarean section. It is easy to perform and provides a reliable, safe, effective, and fast sensory and motor block of high quality. Hypotension, which can be deleterious to both mother and baby, is however a common side effect. Preloading has not been shown to consistently prevent spinal-induced hypotension. AIM: The aim of this study was to compare coloading with preloading using crystalloids for preventing spinal anesthesia-induced hypotension in parturients undergoing scheduled cesarean delivery. MATERIALS AND METHODS: A single-blinded, randomized, and controlled study was conducted on 88 patients at term scheduled for elective cesarean delivery under spinal anesthesia at the Korle-Bu Teaching Hospital. Parturients were randomly assigned to receive a preload of 12.5 mL/kg of Ringer’s Lactate (Group P) before the spinal anesthetic or a coload of 12.5 mL/kg of Ringers Lactate (Group C) at the time of the spinal procedure. Blood pressure, heart rate, incidence and timing of nausea and vomiting, and amount and frequency of vasopressor used were recorded for the first 10 minutes post-spinal anesthesia. Neonatal Apgar scores were determined at 1 and 5 minutes after birth. RESULTS: The two groups were comparable with respect to age, weight, height, gestational age, ASA classification, baseline hemodynamic measurements, time to onset of hypotension, and time to delivery of baby post-spinal anesthesia. Post-spinal anesthesia changes in the heart rate, systolic blood pressure and mean arterial blood pressure were also comparable between the two groups. None of the patients in both groups experienced nausea or vomiting without hypotension. Although the cumulative dose of ephedrine to treat hypotension in the preload group was higher compared to the coload group, the difference was not statistically significant (16.3 vs. 12.4; p-value = 0.110). CONCLUSION: Preloading and coloading with 12.5 mL/kg of Ringer’s Lactate are comparable but neither is effective alone for preventing spinal-induced hypotension in the obstetric population. A vasopressor regimen is required to improve efficacy of the fluid load for preventing spinal-induced hypotension.

Colloid Preload versus Crystalloid Co-Load in the Setting of Norepinephrine Infusion during Cesarean Section: Time and Type of Administered Fluids Do Not Matter.

Background and Goal of Study: Spinal anesthesia for cesarean section is frequently associated with a high incidence of hypotension, which may bring about untoward effects for both the mother and fetus. Recently, norepinephrine has emerged as a promising alternative in maintaining blood pressure in the obstetric setting. Fluid administration is another technique still widely used to prevent maternal hypotension. The optimal fluid strategy to prevent maternal hypotension has not been elucidated yet. It has been recently suggested that the main strategy in the prevention and management of hypotension should be the combination of vasoconstrictive medications and fluid administration. The aim of this randomized study was to compare the incidence of maternal hypotension in parturients receiving either colloid preload or crystalloid co-load in the setting of prophylactic norepinephrine infusion during elective cesarean section under combined spinal-epidural anesthesia. Materials and Methods: After ethics committee approval, 102 parturients with full-term singleton pregnancies were randomly allocated to either 6% hydroxyethyl starch 130/0.4 5 mL/kg before the onset of spinal anesthesia (colloid preload group) or Ringer's lactate solution 10 mL/kg concurrent with the subarachnoid injection (crystalloid co-load group). In both groups, norepinephrine 4 μg/min starting simultaneously with the administration of the subarachnoid solution was also administered. The primary outcome of the study was the incidence of maternal hypotension, defined as systolic arterial pressure (SAP) <80% of baseline. The incidence of severe hypotension (SAP < 80 mmHg), total dose of vasoconstrictive agents administered, as well as the acid-base status and Apgar score of the neonate and any incidence of maternal side effects were also recorded. Results: Data analysis was performed on 100 parturients: 51 in the colloid preload group and 49 in the crystalloid co-load group. No significant differences were demonstrated between the colloid preload group and the crystalloid co-load group in the incidence of hypotension (13.7% vs. 16.3%, p = 0.933) or the incidence of severe hypotension (0% vs. 4%, p = 0.238). The median (range) ephedrine dose was 0 (0-15) mg in the colloid preload group and 0 (0-10) mg in the crystalloid co-load group (p = 0.807). The incidence of bradycardia, reactive hypertension, requirement for modification of vasopressor infusion, time to the first occurrence of hypotension, and maternal hemodynamics did not differ between the two groups. There were no significant differences in other maternal side effects or neonatal outcomes between groups. Conclusions: The incidence of hypotension with a norepinephrine preventive infusion is low and comparable with both colloid preload and crystalloid co-load. Both fluid-loading techniques are appropriate in women undergoing cesarean delivery. It appears that the optimal regimen for prevention of maternal hypotension is a combined strategy of a prophylactic vasopressor such as norepinephrine and fluids.

EFFECT OF PRELOADING V/S COLOADING OF CRYSTALLOID INFUSION ON MATERNAL HYPOTENSION AFTER SPINAL ANESTHESIA FOR ELECTIVE CESAREAN SECTION: A RANDOMISED COMPARATIVE STUDY

Background: Spinal anesthesia induced hypotension is a major complication in parturient. Intravenous crystalloids administration is a routine practice to prevent and treat maternal hypotension. However, timing of infusion is yet to be determined. We therefore compared preloading with coloading to determine the optimal timing of infusion for prevention of maternal hypotension post spinal anaesthesia. Methods: Seventy parturients were randomized to receive 15ml/kg of crystalloid before (preload group) or after (coload group) intrathecal drug injection for spinal anesthesia. Primary objectives of this study were to look for incidence of intra operative hypotension and total dose of ephedrine used, while secondary objectives were hemodynamic variables, neonatal outcome (apgar scores) and the incidence of maternal nausea and vomiting. Data were expressed as mean (SD) or number (%) as indicated and were compared using chi-square, sher's exact, or student's t test as appropriate. Results: Parturient in preload group (PL) had higher incidence of spinal anesthesia induced hypotension (85.71%) as compare to coload group (CL) (65.71%) but the difference was statistically insignicant(p=0.051). Lower doses of ephedrine were used in coload group median 6 mg (range 0-24mg) then preload group median 12 mg (range0-24mg) p=0.0002. Nausea and vomiting were lower in coload group (14.29%) as compare to preload group (20%) but were statistically insignicant. Apgar score was comparable between both groups. Conclusion: Crystalloid are recommended at the time of block (coload) in parturients undergoing spinal anesthesia to prevent post spinal maternal hypotension and vasopressor requirement.

Comparison of colloid preloading and continuous infusion of norepinephrine versus crystalloid co-loading and continuous infusion of norepinephrine in the prevention of maternal hypotension

Background and goal of study: Spinal anesthesia for cesarean section can be frequently complicated by hypotension, with untoward effects for both the mother and fetus. Recently, norepinephrine has been shown to be effective in maintaining blood pressure in obstetric patients. Another technique widely used to prevent hypotension is fluid administration. Current evidence suggests that the combination of fluid administration and vasoconstrictive medications should be the main strategy for prevention and management of hypotension. The aim of this randomized study was to investigate the combination of a norepinephrine infusion and colloid preloading versus the combination of a norepinephrine infusion and crystalloid co-loading for the prevention of maternal hypotension during elective cesarean section under combined spinal-epidural anaesthesia Materials and methods: One hundred parturients were randomized to receive either 6% hydroxyethyl starch 130/0.4 5 mL/kg before spinal anesthesia (colloid preload) or Ringer’s Lactate solution 10 mL/kg starting with intrathecal injection (crystalloid co-load). Both groups were also administered norepinephrine 4 μg/min, starting simultaneously with the administration of the subarachnoid solution. The primary outcome was the incidence of maternal hypotension (SBP <80% of baseline). The incidence of severe hypotension (SAP <80 mmHg), total dose of ephedrine administered as well as maternal side-effects and the acid-base status and Apgar score of the neonate were also recorded Results: There were no significant differences in the incidence of hypotension (13.7% vs. 16.3%, P = 0.933 or severe hypotension (0% vs. 4%, P = 0.238) between colloid preload and crystalloid co-load groups, respectively. The median [range] ephedrine dose was 0 [0–15] mg in the colloid preload group and 0 [0–10] mg in the crystalloid co-load group (P = 0.807). There were no significant differences in maternal side-effects or neonatal outcomes between groups Conclusion: The incidence of hypotension during elective cesarean section is low and comparable when a norepinephrine infusion is used in combination with either colloid preload or crystalloid co-load, with perhaps a marginal superiority of colloid preload in the prevention of severe hypotension. It appears that the optimal regimen for prevention of maternal hypotension is a combination of fluids and a prophylactic vasopressor like norepinephrine.

A COMPARATIVE STUDY BETWEEN THE EFFECT OF PRE-LOAD COLLOID AND CO-LOAD CRYSTALLOID ADMINISTRATION ON BLOOD PRESSURE AFTER SPINAL ANESTHESIA IN ELECTIVE CESAREAN DELIVERY

Background: Hypotension following spinal anaesthesia is a common complication with an incidence ranging from 25-75% among general population and a little higher in women undergoing Caesarean section with more intraoperative and postoperative morbidity. Several techniques and protocols have been used for the prevention of this neuraxial hypotension with varying degree of success. Aim of the study: to compare the effect of pre-load colloid and co-load crystalloid fluid administration on maternal blood pressure during spinal anesthesia for Cesarean delivery. Patients and Methods: This Prospective, randomized, comparative clinical trial included fifty pregnant women whounderwent elective cesarean section under spinal anesthesia, aging 25-35 years old. The patients were divided into two equal groups, Pre-load group:received rapid infusion of a colloid solution 10 ml/kg of Voluven [6% Hydroxyethyl starch 130/0.4 in 0.9 Sodium Chloride] over 20 minutes before initiation of spinal anaesthesia.Co-load group: patients received a crystalloid solution 20ml/kg of lactated Ringer’s solution at the beginning of the procedure of spinal anaesthesia over 20 minutes. Results: There were no statistically significant differences between both groups regarding systolic, diastolic and mean blood pressure, as well as Oxygen saturation and heart rate at all times. Side effects (nausea and vomiting) and blood loss were insignificantly less in the co-load group compared to pre-load group. There was no statistically significant difference between both groups in Apgar score at 1min. and at 5min. There were no statistically significant differences between groups in the need for ephedrine and total dose administered. Conclusion: There is no significant difference between both groups in prevention of spinal anesthesia- induced hypotension in elective cesarean cases. Valuable time need not be wasted in preloading parturient as preloading alone is not effective for the prevention of maternal hypotension during a cesarean section underspinal anesthesia.

A Comparison of Crystalloid Preloading and Co-Loading to Prevent Spinal Anaesthesia Induced Hypotension in Caesarean Section

Background: Preloading of crystalloid is a traditional practice to prevent spinal anaesthesia inducedhypotension. But co-loading seems to be more physiological and rational approach as effect was achievedduring the time of spinal anaesthesia. Aims: To compare the efficacy of crystalloid preloading and co-loading for prevention of hypotensionduring spinal anaesthesia in caesarean section. Methods: This study was conducted in Department of Anaesthesia, Analgesia and Critical Care, CombinedMilitary Hospital (CMH), Chittagong. Study was carried out over a period of six months from January toJune 2017. Total 80 patients (40 in each group) were included in this study. Patients with ASA grade 1&amp; 2, aged 18-40 years were included. Patients with complicated pregnancy or failed spinal were excluded.Group-P (Preload group) received 15ml/kg Crystalloid solution (Hartmann’s solution/lactated Ringer’ssolution), 20 min before administration of spinal anaesthesia. Group-C (Co-load group) received bolus of15 ml/kg Crystalloid solution (Hartmann’s solution /lactated Ringer’s solution) at time of administrationof spinal anaesthesia. Blood pressure was recorded at 1, 2, 3, 5 &amp; 10 minutes. Patients received vasopressorswhen mean blood pressure reduced below 20 mm of Hg or systolic blood pressure dropped below 90mmHg. Results: Total study population was 80 patients underwent caesarean section. Mean age of the patientswas 28.36±5.08 years and 28.25±5.06 years in group-P and C, respectively. Overall hypotension was notedin 23 patients (57.5%) of group-P and 19 patients (47.5%) of group-C. The difference between two groupswas statistically insignificant (p=0.241). After induction of spinal anaesthesia at 1 minute hypotensionwas noted in 7 patients (17.5%) of group-P and in 13 patients (32.5%) of group-C, at 2 minutes in 21patients (52.5%) of group-P and in 22 patients (55%) of group-C, at 3 minutes in 23 patients (57.5%) ofgroup-P and in 24 patients (60.0%) of group-C, at 5 minutes in 17 patients (42.5%) of group-P and in 19patients (47.5%) of group-C, at 10 minutes in 13 patients (32.5%) of group-P and in 7 patients (17.5%) ofgroup-C hypotension was developed. Conclusion: Both preloading and co-loading with 15 ml/kg of Crystalloid solution (Hartmann’s solution/lactated Ringer’s solution) when used alone, are ineffective for the prevention of hypotension in caesareansection receiving spinal anaesthesia. We recommend frequent monitoring of maternal blood pressure andprompt treatment of maternal hypotension with vasopressors for better neonatal outcomes. JBSA 2017; 30(2): 83-89

Crystalloid Coload Reduced the Incidence of Hypotension in Spinal Anesthesia for Cesarean Delivery, When Compared to Crystalloid Preload: A Meta-Analysis.

Objective To determine whether crystalloid infusion just after intrathecal injection (coload) would be better than infusion before anesthesia (preload) for hypotension prophylaxis in spinal anesthesia for cesarean delivery. Methods We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and other databases for randomized controlled trials comparing coload of crystalloid with preload in parturients receiving spinal anesthesia for cesarean delivery. Primary outcome was intraoperative incidence of hypotension. Other outcomes were intraoperative need for vasopressors, hemodynamic variables, neonatal outcomes (umbilical artery pH and Apgar scores), and the incidence of maternal nausea and vomiting. We used RevMan 5.2 and STATA 12.0 for the data analyses. Results Ten studies with 824 cases were included. The incidence of hypotension was significantly higher in the preload group compared with the coload group (57.8% versus 47.1%, odds ratio [OR] = 1.62, 95% confidence interval [CI] = 1.11–2.37, and P = 0.01). More patients needed intraoperative vasopressors (OR = 1.71, 95% CI = 1.07–2.04, and P = 0.02) when receiving crystalloid preload. In addition, the incidence of nausea and vomiting was higher in the preload group (OR = 3.40, 95% CI = 1.88–6.16, and P < 0.0001). There were no differences in neonatal outcomes between the groups. Conclusions For parturients receiving crystalloid loading in spinal anesthesia for cesarean delivery, coload strategy is superior to preload for the prevention of maternal hypotension.

Comparison between colloid preload and crystalloid co-load in cesarean section under spinal anesthesia: a randomized controlled trial

BackgroundHypotension is a common problem during spinal anesthesia for cesarean delivery. Intravenous fluid loading is used to correct preoperative dehydration and reduce the incidence and severity of hypotension. Different fluid regimens have been studied but colloid preload and crystalloid co-load have not been compared. MethodsIn this randomized double-blind study, 210 patients scheduled for elective cesarean section under spinal anesthesia were randomly allocated to receive either 6% hydroxyethyl starch 130/0.4 500mL before spinal anesthesia (colloid preload) or Ringer’s acetate solution 1000mL administered rapidly starting with intrathecal injection (crystalloid co-load). Maternal hypotension (systolic blood pressure <80% of baseline or <90mmHg) and severe hypotension (systolic blood pressure <80mmHg) were treated with 5 and 10mg ephedrine boluses, respectively. The primary outcome was the incidence of hypotension. Secondary outcomes included the incidence of severe hypotension, total ephedrine dose, nausea and vomiting and neonatal outcome assessed by Apgar scores and umbilical artery blood gas analysis. ResultsData analysis was performed on 205 patients; 103 in the colloid preload group and 102 in the crystalloid co-load group. There were no significant differences in the incidence of hypotension (52.4% vs. 42.2%; P=0.18) or severe hypotension (15.5% vs. 9.8%; P=0.31) between colloid preload and crystalloid co-load groups, respectively. The median [range] ephedrine dose was 5 [0–45]mg in the colloid preload group and 0 [0–35]mg in the crystalloid co-load group (P=0.065). There were no significant differences in maternal nausea or vomiting or neonatal outcomes between groups. ConclusionThe use of 1000mL crystalloid co-load has similar effect to 500mL colloid preload in reducing the incidence of hypotension after spinal anesthesia for elective cesarean delivery. Neither technique can totally prevent hypotension and should be combined with vasopressor use.

English

CONTEXT: Preloading of crystalloid is a traditional practice to prevent spinal anaesthesia induced hypotension. But coloading seems to be more physiological and rational approach as effect was achieved during the time of spinal anaesthesia. AIMS: To compare crystalloid preload and coload for the prevention of spinal block induced hypotension in lower limb surgeries. Secondary outcomes included no. of dose of mephenteramine & atropine, bradycardia, nausea, vomiting, total volume of infusion, blood loss & urine output. SETTINGS AND DESIGN: Tertiary level, teaching hospital. Prospective, randomized study. MATERIALS AND METHODS: Total sixty patients of either sex, aged 20 to 60 years, scheduled for lower limb surgery under spinal anaesthesia were randomized into preload and coload group, 30 patients in each group. In preload group, 20 ml/kg of Ringer lactate was preloaded 20 minutes before commencement of spinal anaesthesia. In group Coload, 20 ml/kg of Ringer lactate was coloaded in 20 minutes just after lumbar puncture. STATISTICAL ANALYSIS USED: Quantitative data were compared with student's t test and qualitative data with chi-square or fisher exact test. P 0.05). Mean baseline value and trends at various time intervals of heart rate, systolic blood pressure, diastolic blood pressure, mean blood pressure were comparable in both groups. Total incidence of hypotension in group Preload and group Coload were 13.33% and 10% respectively (p=0.463). Total incidence of bradycardia in group Preload and group Coload were 6.67% and 10% respectively (p=0.394). No. of dose of atropine to treat bradycardia was 2 out of 30 patients (6.67%) and 3 out of 30 patients (10%) for group P and C respectively (p=0.394). No. of dose of mephenteramine to treat hypotension was 4 out of 30 patients (13.33%) for each group (p=1). Incidence of nausea was 6.67% for group Preload and 10% for group Coload (p=0.394). Incidence of vomiting was 3.33% for group Preload and 6.67 % for group Coload (p=0.278). Total volume used for preloading was about 1474 ± 206 ml and for coloading was 1386 ± 176 ml (p=0.0805). Urine output in preloading and coloading groups was 223 ± 100 and 173 ± 89 ml respectively (p=0.0453). CONCLUSIONS: Coloading with 20 ml/kg of Ringer's lactate was as effective as preloading of same amount 20 minute before lumber puncture to prevent spinal induced hypotension.

Preload or Coload for Spinal Anesthesia for Elective Cesarean Delivery

Hypotension following spinal anesthesia for Cesarean delivery is common. Fluid loading is recommended to prevent hypotension, but preload is often ineffective. In non-pregnant patients, coloading has been shown to better maintain cardiac output after spinal anesthesia. The purpose of this meta-analysis was to determine whether the timing of the fluid infusion, before (preload) or during (coload) induction of spinal anesthesia for Cesarean delivery, influences the incidence of maternal hypotension or neonatal outcome. We retrieved randomized controlled trials that compared a fluid preload with coload in patients undergoing spinal anesthesia for elective Cesarean delivery. We graded the articles for quality of reporting (maximum score = 5) and recorded the incidence of hypotension, lowest blood pressure, the incidence of maternal nausea and vomiting, umbilical cord pH, and Apgar scores. We combined the results using random effects modelling. We retrieved eight studies comprised of 518 patients. The median quality score for the published studies was three. The incidence of hypotension in the coload group was 159/268 (59.3%) compared with 156/250 (62.4%) in the preload group (odds ratio [OR] = 0.93; 95% confidence interval [CI] 0.54–1.6). There were no significant differences between groups in any of the other outcomes. It is unnecessary to delay surgery in order to deliver a preload of fluid. Regardless of the fluid loading strategy, the incidence of maternal hypotension is high. Prophylactic or therapeutic vasopressors may be required in a significant proportion of patients.

Preload or coload for spinal anesthesia for elective Cesarean delivery: a meta-analysis

Hypotension following spinal anesthesia for Cesarean delivery is common. Fluid loading is recommended to prevent hypotension, but preload is often ineffective. In non-pregnant patients, coloading has been shown to better maintain cardiac output after spinal anesthesia. The purpose of this meta-analysis was to determine whether the timing of the fluid infusion, before (preload) or during (coload) induction of spinal anesthesia for Cesarean delivery, influences the incidence of maternal hypotension or neonatal outcome. We retrieved randomized controlled trials that compared a fluid preload with coload in patients undergoing spinal anesthesia for elective Cesarean delivery. We graded the articles for quality of reporting (maximum score = 5) and recorded the incidence of hypotension, lowest blood pressure, the incidence of maternal nausea and vomiting, umbilical cord pH, and Apgar scores. We combined the results using random effects modelling. We retrieved eight studies comprised of 518 patients. The median quality score for the published studies was three. The incidence of hypotension in the coload group was 159/268 (59.3%) compared with 156/250 (62.4%) in the preload group (odds ratio [OR] = 0.93; 95% confidence interval [CI] 0.54-1.6). There were no significant differences between groups in any of the other outcomes. It is unnecessary to delay surgery in order to deliver a preload of fluid. Regardless of the fluid loading strategy, the incidence of maternal hypotension is high. Prophylactic or therapeutic vasopressors may be required in a significant proportion of patients.

A Randomized Trial Comparing Colloid Preload to Coload During Spinal Anesthesia for Elective Cesarean Delivery

Hypotension after spinal anesthesia for cesarean delivery is common. Previous studies have demonstrated that a crystalloid fluid "coload" (rapid administration of a fluid bolus starting at the time of intrathecal injection) is superior to the conventional crystalloid preload (fluid administered before the intrathecal injection) for preventing hypotension. Colloid preload provides a sustained increase in central blood volume. We hypothesized that, in contrast to crystalloid, a colloid preload may be more effective than colloid coload for reducing the incidence of spinal anesthesia-induced hypotension. In this double-blind study, 178 patients were randomly assigned to receive a preload of 500 mL of hydroxyethyl starch over a period of 15-20 min before initiation of spinal anesthesia (n = 90) or an identical fluid bolus of hydroxyethyl starch starting at the time of identification of cerebrospinal fluid (n = 88). Vasopressors (ephedrine or phenylephrine) were administered if systolic arterial blood pressure decreased less than 80% of the baseline pressure and <100 mm Hg, or with smaller decreases in blood pressure if accompanied by nausea, vomiting, or dizziness. The primary outcome was the incidence of hypotension (defined as the administration of at least one dose of vasopressor). There was no significant difference between the groups in the incidence of hypotension (68% in preload group and 75% in coload group, 95% confidence interval of difference -6%-20%; P = 0.28), doses of ephedrine and phenylephrine, and number of vasopressor unit doses. The incidence of severe hypotension (systolic blood pressure <80 mm Hg) was 16% in the preload group and 22% in the coload group (P = 0.30). There were no differences in the incidence of nausea and/or vomiting, or neonatal outcome between the groups. There was no difference in the incidence of hypotension in women who received colloid administration before the initiation of spinal anesthesia compared with at the time of initiation of anesthesia. Both modalities are inefficient as single interventions to prevent hypotension.

Comparison of effects of rapid colloid loading before and after spinal anesthesia on maternal hemodynamics and neonatal outcomes in cesarean section

The effects of colloid loading after spinal anesthesia on hemodynamics in parturients during cesarean section have not been fully understood. This study tested the hypothesis that colloid loading after spinal blockade can reduce hypotension compared with preloading, and affect neonatal outcomes. A prospective, randomized, double-blinded study was performed in 54 healthy parturients (ASA I or II) undergoing elective cesarean section. Patients were randomly allocated into one of three groups to receive rapid infusion of 6% hydroxyethylstarch (HES) (70 kDa/0.5) before spinal anesthesia (15 ml x kg(-1), HES preload group, n = 18), or rapid infusion of HES after induction of spinal anesthesia (15 ml x kg(-1), HES coload group, n = 18), or no rapid infusion (control, n = 18). The incidence of hypotension, and the amount of ephedrine used to treat hypotension was compared. Neonatal outcomes were also assessed by pH, base excess, lactate concentration, and Apgar scores. The incidence of hypotension was significantly lower in HES preload and HES coload groups than control group (P < 0.01). Although systolic blood pressure decreased after spinal blockade in all groups, the lowest SBP after spinal blockade until delivery was significantly higher in fluid loading groups than control (P < 0.001). Similarly, total dose of ephedrine to treat hypotension was lower in fluid loading groups (P < 0.001). Umbilical cord pH, umbilical lactate concentration, and the incidence of neonates with Apgar score <7 were similar. Colloid loading after induction of spinal anesthesia was similarly effective in reducing hypo- tension compared with preloading in cesarean section.