Search Results (31)

Background: Remifentanil, an ultra-short-acting µ-receptor agonist, is used with propofol for optimal laryngeal mask airway (LMA) insertion. However, no studies have assessed its effects when combined with thiopental on LMA conditions. The combined use of thiopental and remifentanil may offer advantages, such as enhanced cardiovascular and respiratory stability. This study aims to compare the administration of thiopental with different doses of remifentanil to assess their combined effects on LMA insertion conditions and success in a prospective, randomised double-blind study. Method: A total of 100 ASA I–II patients (18–65 years), including both male and female participants, were randomly assigned to four remifentanil dose groups (0.5–3 µg.kg⁻¹). Induction involved thiopental (5 mg.kg⁻¹) after remifentanil. LMA insertion conditions were evaluated using a six-variable scale. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), heart rate (HR), and bispectral index monitor (BIS) values, as well as apnoea duration, eyelash reflex loss time, and insertion attempts, were recorded at baseline, before insertion, and at 5 min post-insertion. Results: Time to eyelash reflex loss and LMA insertion were shorter in Groups III and IV than in Groups I and II (p < 0.001). Apnoea duration was longest in Group IV, followed by Group III (p < 0.001). Groups III and IV had significantly better LMA placement, mouth opening, and ease of insertion (p < 0.05). Coughing and gagging were highest in Group I (p < 0.001). SAP, MAP, HR, and DAP were significantly lower in Group IV at various time points (p < 0.05). HR was significantly higher in Group I compared to Groups II and III at multiple time points (p < 0.05). Conclusions: The administration of 5 mg.kg⁻¹ thiopental with 2 μg.kg⁻¹ remifentanil has been found to provide a stable haemodynamic response and 96% excellent or satisfactory laryngeal mask insertion conditions without increasing the duration of apnoea. Full article

Background and Objectives: Dexmedetomidine is a potent selective α₂ receptor agonist with analgesic and sedative effects. Many reports indicate that compared to fentanyl, the combination of dexmedetomidine with propofol provides comparably acceptable conditions for a laryngeal mask airway (LMA). However, no study has evaluated the effectiveness of combined dexmedetomidine and thiopental in LMA insertions compared to that of combined dexmedetomidine and propofol. This prospective, randomized, double-blind study aimed to compare the effects of dexmedetomidine with thiopental or propofol on LMA insertion conditions, hemodynamic responses, and pharyngolaryngeal morbidity, which in this study was defined as the presence of postoperative sore throat, dysphagia, or visible blood in the airway following a laryngeal mask airway (LMA) insertion. Materials and Methods: A total of 80 premedicated ASA I-II patients aged 18–65 years were randomized to the propofol group (Group P, n = 40) or thiopental group (Group T, n = 40). Anesthesia was induced by infusing 1 μg·kg⁻¹ dexmedetomidine over 10 min followed by 2.5 mg·kg⁻¹ propofol or 5 mg·kg⁻¹ thiopental. LMA insertion conditions were evaluated on a scale assessing six variables. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), heart rate (HR), and bispectral index values were recorded at baseline; 1 min before; and at 1, 2, 3, 4, and 5 min after an LMA insertion. The baseline values for the systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), heart rate (HR), and bispectral index (BIS) values were recorded before dexmedetomidine infusion. Measurements for all patients were then taken 1 min before and at 1, 2, 3, 4, and 5 min after the LMA insertion Results: Demographic data were similar between the groups. In Group P, the time to loss of eyelash reflex and LMA insertion time were significantly shorter, the apnea duration was significantly longer, and the rates of full jaw opening and optimal LMA insertion conditions were significantly higher when compared with those of Group T (p < 0.05). Group P showed a significantly greater percentage decrease in HR compared to that of Group T at 1 min before and 1, 2, and 3 min after the LMA insertion (p < 0.05). Group T had a greater decrease in SAP and MAP at 1 min before insertion, while the SAP decrease was lower in Group T at 3, 4, and 5 min after insertion. The MAP and DAP values after the LMA insertion showed a greater decrease in Group P compared to in Group T (p < 0.05). The incidence of bradycardia was significantly (p < 0.05) higher in Group P than in Group T. There was no significant difference between the groups in terms of the frequency of hypotension, sore throat, presence of blood, or dysphagia at discharge from the recovery unit (p > 0.05). Conclusions: This study showed that the use of dexmedetomidine with thiopental provided comparably acceptable LMA insertion conditions with more stable hemodynamics compared to propofol. Full article

Noninvasive blood pressure (NIBP) device performance in dogs may be influenced by extreme pressures and altered systemic vascular resistance (SVR). This study evaluated the agreement of two NIBP devices (HDO and petMAP) with invasive blood pressure (IBP) measurements, compliance with hypertension consensus statement criteria, and their trending ability (TA) across varying blood pressure and SVR ranges in awake and anesthetized dogs. Seven healthy Beagles were studied, with IBP recorded from the dorsal metatarsal artery and NIBP cuffs placed randomly on the front limb, hind limb, or base of the tail. Cardiac output was determined by thermodilution, and the systemic vascular resistance index (SVRI) was calculated by a standard formula. Bland–Altman, concordance rate, and polar plot analyses were used for statistical analysis. A total of 752 and 640 paired measurements were obtained for HDO and petMAP, respectively. Both devices showed good agreement with IBP for mean arterial pressure (MAP) at low blood pressure and the SVRI. At high blood pressure and the SVRI, agreement weakened, with substantial underestimation of systolic arterial pressure (SAP). Both devices demonstrated moderate to good TA for MAP and SAP. Overall, the best agreement was observed for MAP at a low SVRI, while agreement was moderate at hypertension (petMAP) and a high SVRI (petMAP, HDO). Full article

Blood pressure (BP) monitoring is essential during anesthesia to maintain cardiovascular stability and detect hypotension. This study evaluated the agreement and diagnostic accuracy of linear deflection oscillometry (LDO) and Doppler compared to invasive blood pressure (IBP) in anesthetized dogs. Eleven healthy dogs were anesthetized, and BP measurements were taken using LDO, Doppler, and IBP methods under normotensive and hypotensive conditions. The LDO device demonstrated superior agreement, assessed using Bland–Altman analysis, with IBP, especially in hypotensive conditions, compared to the Doppler method. LDO showed bias and standard deviation in the hypotensive state, with a mean and systolic arterial pressure (MAP and SAP) of −5.1 ± 7.9 and −5.6 ± 12.5 mmHg, respectively. Conversely, Doppler measurements tended to overestimate SAP during hypotension, presenting a bias of −13 ± 15.45 mmHg. The LDO achieved an area under the curve (AUC) of 0.809 for hypotension detection, with an MAP cutoff of ≤72 mmHg (sensitivity: 90%, specificity: 63%). Meanwhile, the best threshold for Doppler measurements was an AUC of 0.798, SAP ≤ 100 mmHg (sensitivity: 77.8%, specificity: 81.8%). These results indicate that LDO is a reliable method for hypotension detection in anesthetized dogs, with potential applications for real-time monitoring. In contrast, the Doppler method may help confirm hypotension diagnoses. Full article

Visual sphygmomanometer needle oscillation (SNO) can occur before audible return of pulsatile flow (ARPF) when measuring blood pressure by Doppler ultrasound. The aim was to assess the agreement of SNO and ARPF with invasive blood pressure (iABP) in a clinical population of anaesthetised dogs. A total of 35 dogs undergoing surgery in dorsal recumbency necessitating arterial cannulation were included. Paired measurements of iABP and SNO, and iABP and ARPF, were collected. The agreement of non-invasive blood pressure (NIBP) and iABP measurements was analysed with concordance correlation coefficients (CCCs) and Bland–Altman plots. The proportions of SNO and ARPF measurements between 10 and 20 mmHg of iABP were compared. Both SNO and ARPF demonstrated greater agreement with invasive systolic (iSAP) than invasive mean (iMAP) pressures, and SNO demonstrated greater agreement with iSAP than ARPF measurements. The mean differences (95% limits of agreement) for SNO and APRF were −9.7 mmHg (−51.3–31.9) and −13.1 mmHg (−62.2–35.9), respectively. The CCC (95% CI) for SNO was 0.5 (0.36–0.64) and ARPF was 0.4 (0.26–0.54). A significantly greater proportion of SNO measurements were within 20 mmHg of iSAP compared to ARPF. Both NIBP techniques performed more poorly than veterinary consensus recommendations for device validation. Caution should be used clinically when interpreting values obtained by Doppler ultrasound in anaesthetised dogs. Full article

Background: We investigate the role of galantamine on autonomic dysfunction associated with early cardiometabolic dysfunction in the offspring of fructose-overloaded rats. Methods: Wistar rats received fructose diluted in drinking water (10%) or water for 60 days prior to mating. Fructose overload was maintained until the end of lactation. The offspring (21 days after birth) of control and fructose-overloaded animals were divided into three groups: control (C), fructose (F) and fructose + galantamine (GAL). GAL (5 mg/kg) was administered orally until the offspring were 51 days old. Metabolic, hemodynamic and cardiovascular autonomic modulation were evaluated. Results: The F group showed decreased insulin tolerance (KITT) compared to the C and GAL groups. The F group, in comparison to the C group, had increased arterial blood pressure, heart rate and sympathovagal balance (LF/HF ratio) and a low-frequency band of systolic arterial pressure (LF-SAP). The GAL group, in comparison to the F group, showed increased vagally mediated RMSSD index, a high-frequency band (HF-PI) and decreased LF/HF ratio and variance in SAP (VAR-SAP) and LF-SAP. Correlations were found between HF-PI and KITT (r = 0.60), heart rate (r = −0.65) and MAP (r = −0.71). Conclusions: GAL treatment significantly improved cardiovascular autonomic modulation, which was associated with the amelioration of cardiometabolic dysfunction in offspring of parents exposed to chronic fructose consumption. Full article

Background: The prediction of fluid responsiveness in critical patients helps clinicians in decision making to avoid either under- or overloading of fluid. This study was designed to determine whether lung recruitment maneuver (LRM) would have an effect on the predictability of fluid responsiveness by the changes of hemodynamic parameters in pediatric patients who were receiving lung-protective ventilation and one-lung ventilation (OLV). Methods: A total of 34 children, aged 1–6 years old, scheduled for heart surgeries via right thoracotomy were enrolled. Patients were anesthetized and OLV with lung-protection ventilation settings was established, and then, positioned on left lateral decubitus. LRM and volume expansion (VE) were performed in sequence. Heart rate (HR), systolic arterial pressure (SAP), mean arterial pressure (MAP) diastolic arterial pressure (DAP), stroke volume (SV), stroke volume variation (SVV), and pulse pressure variation (PPV) were recorded via an A-line based monitor system at the following time points: before and after LRM (T1 and T2) and before and after VE (T3 and T4). An increase in stroke volume (SV) or mean arterial pressure (MAP) of ≥10% following fluid loading identified fluid responders. The predictability of fluid responsiveness by the changes of SV (ΔSV_LRM) and MAP (ΔMAP_LRM) after LRM and VE were statistically evaluated by receiver operating characteristic curves [area under the curves (AUC)]. Results: SVs in all patients were significantly decreased after LRM (p < 0.01) and then, increased and returned to baseline after VE (p < 0.01). In total, 16 out of 34 patients who were fluid responders had significantly lower SV after LRM compared to that in fluid non-responders. The area under the receiver operating characteristic curves for ΔSV_LRM was 0.828 (95% confidence interval [CI], 0.660 to 0.935; p < 0.001) and it indicated that ΔSV_LRM was able to predict the fluid responsiveness of pediatric patients. MAPs in all patients were also decreased significantly after LRM, and 12 of them fell into the category of fluid responders after VE. Statistically, ΔMAP_LRM did not predict fluid responsiveness when LRM was considered as an influential factor (p = 0.07). Conclusions: ΔSV_LRM, but not ΔMAP_LRM, showed great reliability in the prediction of the fluid responsiveness following VE in children during one-lung ventilation with lung-protective settings. Trial registration: ChiCTR2300070690. Full article

Recent studies have found increased cardiovascular mortality risk in patients with type 1 diabetes when compared to normoglycemic people, even when they were kept under good glycemic control. However, the mechanisms underlying this condition have yet to be fully understood. Using streptozotocin (STZ)-induced diabetic rats, we evaluated the effects of insulin replacement therapy on cardiac, autonomic, inflammatory, and oxidative stress parameters. Daily treatment with insulin administrated subcutaneously in the STZ-diabetic rats showed a reduction in hyperglycemia (>250 mg/dL) to normalized values. The insulin treatment was effective in preventing alterations in cardiac morphometry and systolic function but had no impact on diastolic function. Also, the treatment was not able to prevent the impairment of baroreflex-tachycardic response and systolic arterial pressure variability (SAP-V). A correlation was found between improvement of these autonomic parameters and higher levels of IL-10 and lower levels of oxidized glutathione. Our findings show that insulin treatment was not able to prevent diastolic, baroreflex, and SAP-V dysfunction, suggesting an outstanding cardiovascular risk, even after obtaining a good glycemic control in STZ-induced diabetic rats. This study shed light on a relatively large population of diabetic patients in need of other therapies to be used in combination with insulin treatment and thus more effectively manage cardiovascular risk. Full article

Oxidative stress (OS) is caused by an imbalance between the production of oxygen-containing free radicals and their elimination. General anesthesia increases the production of reactive oxygen species (ROS) and therefore causes oxidative stress. Our objective was to determine the effects of medetomidine–butorphanol (MEDBUT) and medetomidine–buprenorphine (MEDBUP) on oxidative stress and cardiorespiratory parameters in dogs undergoing ovariohysterectomy (OHE). Ten healthy female dogs were randomly assigned to two groups: the MEDBUT group (n = 5) received medetomidine and butorphanol, while the MEDBUP group (n = 5) received medetomidine and buprenorphine. OS was evaluated by measuring total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) during five different time points (from the administration of anesthetic drugs to 2 h after surgery). The observed vital cardiorespiratory parameters included heart rate (HR), respiratory rate (fR), noninvasive systolic (SAP) and diastolic (DAP) arterial blood pressures, oxygen saturation (SpO₂), end-tidal CO₂ (EtCO₂), and body temperature (BT). Cardiorespiratory parameters were altered at a significantly greater degree in animals sedated with MEDBUT (p < 0.05). The administration of medetomidine–butorphanol was more likely to increase OS parameters, while medetomidine–buprenorphine showed decreased levels of oxidative stress throughout the study. Full article

Background: Autonomic function and baroreflex control might influence the survival rate of coronavirus disease 2019 (COVID-19) patients admitted to the intensive care unit (ICU) compared to respiratory failure patients without COVID-19 (non-COVID-19). This study describes physiological control mechanisms in critically ill COVID-19 patients admitted to the ICU in comparison to non-COVID-19 individuals with the aim of improving stratification of mortality risk. Methods: We evaluated autonomic and baroreflex control markers extracted from heart period (HP) and systolic arterial pressure (SAP) variability acquired at rest in the supine position (REST) and during a modified head-up tilt (MHUT) in 17 COVID-19 patients (age: 63 ± 10 years, 14 men) and 33 non-COVID-19 patients (age: 60 ± 12 years, 23 men) during their ICU stays. Patients were categorized as survivors (SURVs) or non-survivors (non-SURVs). Results: We found that COVID-19 and non-COVID-19 populations exhibited similar vagal and sympathetic control markers; however, non-COVID-19 individuals featured a smaller baroreflex sensitivity and an unexpected reduction in the HP-SAP association during the MHUT compared to the COVID-19 group. Nevertheless, none of the markers of the autonomic and baroreflex functions could distinguish SURVs from non-SURVs in either population. Conclusions: We concluded that COVID-19 patients exhibited a more preserved baroreflex control compared to non-COVID-19 individuals, even though this information is ineffective in stratifying mortality risk. Full article

Introduction: Mobile health diagnostics have demonstrated effectiveness in detecting and managing chronic diseases. This method comparison study aims to assess the accuracy and precision of the previously evaluated OptiBP™ technology over a four-week study period. This device uses optical signals recorded by placing a patient’s fingertip on a smartphone’s camera to estimate blood pressure (BP). Methods: In adult participants without cardiac arrhythmias and minimal interarm blood pressure difference (systolic arterial pressure (SAP) < 15 mmHg or diastolic arterial pressure (DAP) < 10 mmHg), three pairs of 30 s BP measurements with the OptiBP™ (test method) were simultaneously compared using three pairs of measurements with the non-invasive oscillometric brachial cuff (reference method) on the opposite arm over a period of four consecutive weeks at a rate of two measurements per week (one in the morning and one in the afternoon). The agreement of BP values between the two technologies was analyzed using Bland–Altman and error grid analyses. The performance of the smartphone application was investigated using the International Organization for Standardization (ISO) definitions, which require the bias ± standard deviation (SD) between two technologies to be lower than 5 ± 8 mmHg. Results: Among the 65 eligible volunteers, 53 participants had adequate OptiBP™ BP values. In 12 patients, no OptiBP™ BP could be measured due to inadequate signals. Only nine participants had known chronic arterial hypertension and 76% of those patients were treated. The mean bias ± SD between both technologies was −1.4 mmHg ± 10.1 mmHg for systolic arterial pressure (SAP), 0.2 mmHg ± 6.5 mmHg for diastolic arterial pressure (DAP) and −0.5 mmHg ± 6.9 mmHg for mean arterial pressure (MAP). Error grid analyses indicated that 100% of the pairs of BP measurements were located in zones A (no risk) and B (low risk). Conclusions: In a cohort of volunteers, we observed an acceptable agreement between BP values obtained with the OptiBP^TM and those obtained with the reference method over a four-week period. The OptiBP^TM fulfills the ISO standards for MAP and DAP (but not SAP). The error grid analyses showed that 100% measurements were located in risk zones A and B. Despite the need for some technological improvements, this application may become an important tool to measure BP in the future. Full article

Background and Objectives: Supine-to-prone hypotension is caused by increased intrathoracic pressure and decreased venous return in the prone position. Dynamic arterial elastance (Ea_dyn) indicates fluid responsiveness and can be used to predict hypotension. This study aimed to investigate whether Ea_dyn can predict supine-to-prone hypotension. Materials and Methods: In this prospective, observational study, 47 patients who underwent elective spine surgery in the prone position were enrolled. Supine-to-prone hypotension is defined as a decrease in Mean Arterial Pressure (MAP) by more than 20% in the prone position compared to the supine position. Hemodynamic parameters, including systolic blood pressure (SAP), diastolic blood pressure, MAP, stroke volume variation (SVV), pulse pressure variation (PPV), stroke volume index, cardiac index, dP/dt, and hypotension prediction index (HPI), were collected in the supine and prone positions. Supine-to-prone hypotension was also assessed using two different definitions: MAP_prone < 65 mmHg and SAP_prone < 100 mmHg. Hemodynamic parameters were analyzed to determine the predictability of supine-to-prone hypotension. Results: Supine-to-prone hypotension occurred in 13 (27.7%) patients. Ea_dyn did not predict supine-to-prone hypotension [Area under the curve (AUC), 0.569; p = 0.440]. SAP_supine > 139 mmHg (AUC, 0.760; p = 0.003) and dP/dt_supine > 981 mmHg/s (AUC, 0.765; p = 0.002) predicted supine-to-prone hypotension. MAP_supine, SAP_supine, PPV_supine, and HPI_supine predicted MAP_prone <65 mm Hg. MAP_supine, SAP_supine, SVV_supine, PPV_supine, and HPI_supine predicted SAP_prone < 100 mm Hg. Conclusions: Dynamic arterial elastance did not predict supine-to-prone hypotension in patients undergoing spine surgery. Systolic arterial pressure > 139 mmHg and dP/dt > 981 mmHg/s in the supine position were predictors for supine-to-prone hypotension. When different definitions were employed (mean arterial pressure < 65 mmHg in the prone position or systolic arterial pressure < 100 mmHg in the prone position), low blood pressures in the supine position were related to supine-to-prone hypotension. Full article

Umbilical hernias in calves occur with relative frequency. Most abdominal surgeries can be performed in cattle using standing sedation and local blocks. Romifidine is widely used in calves, alone or in combination with opioids. Tramadol administered as an intravenous slow injection provided better analgesia than an IV bolus in cows. The aim of the present study was to compare the response to surgical stimulus, and sedative effects of tramadol administered intravenously either as a bolus or a slow injection in romifidinesedated calves. Twenty Frisian calves undergoing umbilical hernia repair received romifidine (0.08 mg/kg IM; time 0) followed by tramadol (1 mg/kg IV) 5 min later either as a bolus (n = 10, B group) or a slow injection over 10 min (n = 10, SI group). Surgical area was infiltrated with lidocaine (4 mg/kg). Heart rate (HR), respiratory rate (RR), systolic, dyastolic and mean arterial pressure (SAP, DAP, MAP), sedation scores and response to surgical stimulus were recorded for up to 55 min. After the calves recovered a standing position, postoperative pain scores were assessed for up to 50 min. Sedation scores were significantly higher in the SI group than in the B group at 55 min (p < 0.05). HR, RR, SAP and response to surgical stimulus were significantly higher in the B group than in the SI group (p < 0.05). No significant differences were recorded in postoperative pain scores between groups (p > 0.05). Romifidine IM followed by intravenous tramadol, as a bolus or slow injection and local infiltration with lidocaine provided adequate sedation and analgesia in calves undergoing umbilical hernia repair. Full article

Oral pathologies can cause athletic underperformance. The aim of this study was to determine the effect of malocclusion on maximal aerobic capacity in young athletes with the same anthropometric data, diet, training mode, and intensity from the same athletics training center. Sub-elite track and field athletes (middle-distance runners) with malocclusion (experimental group (EG); n = 37; 21 girls; age: 15.1 ± 1.5 years) and without malocclusion (control group (CG); n = 13; 5 girls; age: 14.7 ± 1.9 years) volunteered to participate in this study. Participants received an oral diagnosis to examine malocclusion, which was defined as an overlapping of teeth that resulted in impaired contact between the teeth of the mandible and the teeth of the upper jaw. Maximal aerobic capacity was assessed using the VAMEVAL test (calculated MAS and estimated VO_2max). The test consisted of baseline values that included the following parameters: maximum aerobic speed (MAS), maximal oxygen uptake (VO_2max), heart rate frequency, systolic (SAP) and diastolic arterial pressure (DAP), blood lactate concentration (LBP), and post-exercise blood lactate assessment (LAP) after the performance of the VAMEVAL test. There were no statistically significant differences between the two study groups related to either anthropometric data (age: EG = 15.1 ± 1.5 vs. CC = 14.7 ± 1.9 years (p = 0.46); BMI: EG = 19.25 ± 1.9 vs. CC = 19.42 ± 1.7 kg/m² (p = 0.76)) or for the following physical fitness parameters and biomarkers: MAS: EG = 15.5 (14.5–16.5) vs. CG = 15.5 (15–17) km/h (p = 0.47); VO_2max: EG = 54.2 (52.5–58.6) vs. CG = 54.2 (53.4–59.5) mL/kg/min (p = 0.62) (IQR (Q1–Q3)); heart rate before the physical test: EG = 77.1 ± 9.9 vs. CG = 74.3 ± 14.0 bpm (p = 0.43); SAP: EG = 106.6 ± 13.4 vs. CG = 106.2 ± 14.8 mmHg (p = 0.91); DAP: EG = 66.7 ± 9.1 vs. CG = 63.9 ± 10.2 mmHg (p = 0.36); LBP: EG = 1.5 ± 0.4 vs. CG = 1.3 ± 0.4 mmol/L (p = 0.12); and LAP: EG = 4.5 ± 2.36 vs. CG = 4.06 ± 3.04 mmol/L (p = 0.60). Our study suggests that dental malocclusion does not impede maximal aerobic capacity and the athletic performance of young track and field athletes. Full article

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. Full article