Impact of Remimazolam versus Sevoflurane Anesthesia on Cerebral Oxygenation and Intracranial Pressure during Gynecological Laparoscopy with Mild Hypercapnia.

BACKGROUND Remimazolam has the advantage of better hemodynamic stability compared with other anesthetics. We compared the effects of remimazolam and sevoflurane on cerebral oxygenation, intracranial pressure, and intraoperative hemodynamic parameters during mild hypercapnia in patients undergoing laparoscopy in the Trendelenburg position. MATERIAL AND METHODS Sixty-two patients (20-65 years old) scheduled for gynecological laparoscopy were randomly allocated to either the remimazolam (n=31) or sevoflurane (n=31) group. Respiratory and hemodynamic parameters and regional cerebral oxygen saturation (rSO2) were recorded. Intracranial pressure was measured using the optic nerve sheath diameter (ONSD). RESULTS The change over time in rSO2 did not differ between groups (P=0.056). The change in ONSD over time showed a significant intergroup difference (P=0.002). ONSD significantly changed over time (P=0.034) in the sevoflurane group but not in the remimazolam group (P=0.115). The changes in mean arterial pressure and heart rate over time showed significant intergroup differences (P=0.045 and 0.031, respectively). The length of stay and the use of rescue antiemetics and analgesics in the postanesthetic care unit were significantly lower in the remimazolam group than in the sevoflurane group (P=0.023, 0.038, and 0.018, respectively). CONCLUSIONS Remimazolam can provide a favorable hemodynamic profile and attenuate the increase in ONSD during gynecological laparoscopy compared with sevoflurane anesthesia during lung-protective ventilation with mild hypercapnia. Remimazolam can provide faster and better postoperative recovery than sevoflurane anesthesia.

Comparisons of Mechanical Power and Respiratory Mechanics in Pressure-Controlled Ventilation and Volume-Controlled Ventilation during Laparoscopic Cholecystectomy in Elderly Patients.

We compared the effects of pressure-controlled volume-guaranteed ventilation (PCV) and volume-controlled ventilation (VCV) on respiratory mechanics and mechanical power (MP) in elderly patients undergoing laparoscopy. Fifty patients aged 65-80 years scheduled for laparoscopic cholecystectomy were randomly assigned to either the VCV group (n = 25) or the PCV group (n = 25). The ventilator had the same settings in both modes. The change in MP over time was insignificant between the groups (p = 0.911). MP significantly increased during pneumoperitoneum in both groups compared with anesthesia induction (IND). The increase in MP from IND to 30 min after pneumoperitoneum (PP30) was not different between the VCV and PCV groups. The change in driving pressure (DP) over time were significantly different between the groups during surgery, and the increase in DP from IND to PP30 was significantly higher in the VCV group than in the PCV group (both p = 0.001). Changes in MP during PCV and VCV were similar in elderly patients, and MP increased significantly during pneumoperitoneum in both groups. However, MP did not reach clinical significance (≥12 J/min). In contrast, the PCV group had a significantly lower increase in DP after pneumoperitoneum than the VCV group.

Effect of Low or High Pressure Alveolar Recruitment Maneuver on Postoperative Pain and Quality of Recovery in Patients with Obesity Undergoing Laparoscopic Sleeve Gastrectomy.

Background: This study aimed to evaluate whether a low- or high-pressure alveolar recruitment maneuver (ARM) might reduce postoperative pain and improve the quality of recovery after laparoscopic bariatric surgery. Methods: 90 patients with a body mass index > 30 kg/m2 scheduled for laparoscopic sleeve gastrectomy were randomly assigned to control (n = 30), low ARM (n = 30), or high ARM groups (n = 30). For the low and high ARM groups, ARM was repeated five times to hold the peak airway pressure at 30 cmH2O and 60 cmH2O for 5 s, respectively, before removal of the trocar. Conventional methods to reduce post-laparoscopic pain, such as intraperitoneal saline irrigation, hemovac drainage, and gentle abdominal compression were performed in all patients, regardless of the assigned group. Results: Shoulder and surgical site pain scores 24 h postoperatively and rescue meperidine requirement were similar between the groups (p = 0.141, 0.101, and 0.82, respectively). The quality of recovery 40 (QoR40) score 24 h postoperatively was similar between the groups (p = 0.755). Postoperative pulmonary complications were similar between the groups (p = 0.124). Conclusion: Application of a low- or high-pressure ARM in addition to conventional methods to remove remnant peritoneal CO2 gas did not reduce postoperative shoulder or surgical site pain or improve the quality of recovery after laparoscopic sleeve gastrectomy.

Effect of Erector Spinae Plane Block on Postoperative Pain after Laparoscopic Colorectal Surgery: A Randomized Controlled Study.

The erector spinae plane (ESP) block can be used to reduce pain and opioid requirements after abdominal surgery. We evaluated the effect of the ESP block on postoperative pain score, analgesic use, and quality of recovery (QoR) score in patients undergoing laparoscopy. Fifty-nine patients undergoing elective laparoscopic colorectal surgery were randomly assigned to control (n = 30) or ESPB (n = 29) groups after anesthesia induction. In the ESPB group, an ultrasound-guided ESP block was performed immediately after induction using 20 mL of 0.5% ropivacaine bilaterally. The primary outcome was the postoperative pain score, which was evaluated using the 11-point numeric rating scale (NRS) (0 = no pain, 10 = worst imaginable pain), in the recovery room. NRS "at rest" and "on cough" and total dose of fentanyl rescue (in the recovery room) as well as NRS "at rest" and the cumulative administered fentanyl dose of patient-controlled analgesia (24 h post-surgery) were significantly lower in the ESPB group than in the control group. The postoperative QoR score did not differ between the groups. Bilateral ESP block after induction reduced pain scores and opioid requirements for 24 h postoperatively but did not improve the QoR in patients undergoing laparoscopic colorectal surgery.

Comparison of remifentanil concentrations with and without dexmedetomidine for the prevention of emergence cough after nasal surgery: a randomized double-blinded trial.

BACKGROUND: Preventing emergence cough after nasal surgery is critical. Emergence cough can provoke immediate postoperative bleeding, which leads to upper airway obstruction. In the present study, we compared the effect-site concentration (Ce) of remifentanil to prevent emergence cough after propofol anesthesia for nasal surgery when remifentanil was or was not combined with dexmedetomidine. METHODS: Forty-seven patients with propofol-remifentanil anesthesia for nasal surgery were randomly assigned to a dexmedetomidine group (Group D, n = 23) or a saline group (Group S, n = 24). Group D and Group S were infused with dexmedetomidine (0.5 µg/kg) and saline, respectively, for 10 min before the completion of surgery. A predetermined Ce of remifentanil was infused until extubation. Remifentanil Ce to prevent cough in 50 and 95% of patients (EC50 and EC95) was estimated using modified Dixon's up-and-down method and isotonic regression. Hemodynamic and recovery parameters were recorded. RESULTS: The EC50 of remifentanil Ce was significantly lower in Group D than in Group S (2.15 ± 0.40 ng/mL vs. 2.66 ± 0.36 ng/mL, p = 0.023). The EC95 (95% CI) of remifentanil Ce was also significantly lower in Group D [2.75 (2.67-2.78) ng/mL] than in Group S [3.16 (3.06-3.18) ng/mL]. Emergence and recovery variables did not differ between the two groups. CONCLUSION: The remifentanil EC50 to prevent cough after propofol-remifentanil anesthesia was significantly lower (approximately 19%) when a combination of remifentanil and 0.5 µg/kg dexmedetomidine was used than when remifentanil infusion alone was used in patients undergoing nasal surgery. Therefore, the Ce of remifentanil may be adjusted to prevent emergence cough when used in combination with dexmedetomidine. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03622502 , August 9, 2018).

Effects of deep neuromuscular block with low-pressure pneumoperitoneum on respiratory mechanics and biotrauma in a steep Trendelenburg position.

We hypothesized that deep neuromuscular blockade (NMB) with low-pressure pneumoperitoneum (PP) would improve respiratory mechanics and reduce biotrauma compared to moderate NMB with high-pressure PP in a steep Trendelenburg position. Seventy-four women undergoing robotic gynecologic surgery were randomly assigned to two equal groups. Moderate NMB group was maintained with a train of four count of 1-2 and PP at 12 mmHg. Deep NMB group was maintained with a post-tetanic count of 1-2 and PP at 8 mmHg. Inflammatory cytokines were measured at baseline, at the end of PP, and 24 h after surgery. Interleukin-6 increased significantly from baseline at the end of PP and 24 h after the surgery in moderate NMB group but not in deep NMB group (Pgroup*time = 0.036). The peak inspiratory, driving, and mean airway pressures were significantly higher in moderate NMB group than in deep NMB group at 15 min and 60 min after PP (Pgroup*time = 0.002, 0.003, and 0.048, respectively). In conclusion, deep NMB with low-pressure PP significantly suppressed the increase in interleukin-6 developed after PP, by significantly improving the respiratory mechanics compared to moderate NMB with high-pressure PP during robotic surgery.

Effects of ventilatory strategy on arterial oxygenation and respiratory mechanics in overweight and obese patients undergoing posterior spine surgery.

Prolonged inspiratory to expiratory (I:E) ratio ventilation may improve arterial oxygenation or gas exchange and respiratory mechanics in patients with obesity. We performed a randomised study to compare the effects of the conventional ratio ventilation (CRV) of 1:2 and the equal ratio ventilation (ERV) of 1:1 on arterial oxygenation and respiratory mechanics during spine surgery in overweight and obese patients. Fifty adult patients with a body mass index of ≥25 kg/m2 were randomly allocated to receive an I:E ratio either l:2 (CRV; n = 25) or 1:1 (ERV; n = 25). Arterial oxygenation and respiratory mechanics were recorded in the supine position, and at 30 minutes and 90 minutes after placement in the prone position. The changes in partial arterial oxygen pressure (PaO2) over time did not differ between the groups. The changes in partial arterial carbon dioxide pressure over time were significantly different between the two groups (P = 0.040). The changes in mean airway pressure (Pmean) over time were significantly different between the two groups (P = 0.044). Although ERV provided a significantly higher Pmean than CRV during surgery, the changes in PaO2 did not differ between the two groups.

Remifentanil-Sparing Effect of Pectoral Nerve Block Type II in Breast Surgery under Surgical Pleth Index-Guided Analgesia during Total Intravenous Anesthesia.

The pectoral nerve block type II (Pecs II block) can provide adequate perioperative analgesia in breast surgery. The surgical pleth index (SPI) is used to monitor the nociception balance using pulse oximetry. We investigated the remifentanil-sparing effect of Pecs II block under SPI guided analgesia during total intravenous anesthesia (TIVA). Thirty-nine patients undergoing breast surgery under remifentanil-propofol anesthesia were randomly assigned to the intervention (Pecs group, n = 20) or control group (n = 19). Remifentanil and propofol concentrations were adjusted to maintain an SPI of 20-50 and a bispectral index of 40-60, respectively. The Pecs group received an ultrasound-guided Pecs II block preoperatively using 30 mL of 0.5% ropivacaine. Total infused remifentanil during the surgery was significantly less in the Pecs group than in the control group (6.8 ± 2.2 µg/kg/h vs. 10.1 ± 3.7 µg/kg/h, p = 0.001). Pain scores on arrival at the postanesthetic care unit (PACU) (3 (2-5) vs. 5 (4-7)) and the rescue analgesic requirement in the PACU (9 vs. 2) was significantly lower in the Pecs group than in the control group. In conclusion, Pecs II block was able to reduce the intraoperative remifentanil consumption by approximately 30% and improve the postoperative pain in PACU in patients undergoing breast surgery under SPI-guided analgesia during TIVA.

Efficacy of Open Debridement and Polyethylene Exchange in Strictly Selected Patients with Infection after Total Knee Arthroplasty.

Purpose: To assess the efficacy of open debridement and polyethylene exchange (ODPE) combined with proper antibiotic therapy in strictly selected patients with infection after total knee arthroplasty (TKA) and analyze factors associated with treatment failure. Materials and Methods: From January 2010 to January 2014, 25 cases that underwent ODPE under the diagnosis of infection within four weeks after TKA or acute hematogenous infection within five days of symptom onset were reviewed in this study. Results: Treatment was successful in 22 out of 25 cases (88.0%). Factors associated with failure were accompanying infection (periprosthetic infection in the ipsilateral foot, cervical parotid abscess, and masticator space abscess) and diagnosis of rheumatoid arthritis (RA) before TKA. Resistant bacteria did not entail a risk. On clinical results, the mean postoperative Lysholm score and Korean Knee score were 81.4 and 79.4, respectively, the knee range of motion was 115.4°±12.9°, and duration of hospitalization was 32.3±8.4 days. On radiographic results, 3.47±1.56 mm joint line elevation and a valgus change of 0.61°±2.35° in knee alignment were observed. Conclusions: ODPE combined with appropriate antibiotics therapy could be a useful treatment method for infection after TKA if the procedure is performed within a symptom duration of five days or less in the absence of accompanying infection in patients whose indication for TKA was not RA.

Stylet angulation for routine endotracheal intubation with McGrath videolaryngoscope.

BACKGROUND: The McGrath videolaryngoscope (VL) provides excellent laryngoscopic views, but directing an endotracheal tube can be difficult, and thus the routine use of a stylet is recommended. The goal of this study is to determine the appropriate angle (60° vs 90°) of the stylet when using the McGrath VL by comparing the time to intubation (TTI). METHODS: One hundred and forty patients aged 19 to 70 years (American Society of Anesthesiologists classification I or II) who required tracheal intubation for elective surgery were randomly allocated to 1 of 2 groups, at the 60° angle (n = 70) or the 90° angle (n = 70). Anesthesia was induced with propofol, fentanyl, and rocuronium. The primary outcome was TTI assessed by a blind observer. Glottic grade, use of optimal external laryngeal manipulation, failed intubation at first attempt, ease of intubation, and severity of oropharyngeal bleeding were also recorded. RESULTS: The mean TTI was significantly shorter in the 60° group than in the 90° group (29.3 ±â€Š6.4 vs 32.5 ±â€Š9.4 s, P = 0.022). The glottic grade and degree of intubation difficulty were not significantly different between the 2 groups. CONCLUSIONS: When intubating the patients with the McGrath videolaryngoscope, the 60° angled stylet allowed for faster orotracheal intubation than did the 90° angled stylet.

Comparison of Intravenous Dexmedetomidine and Midazolam for Bispectral Index-Guided Sedation During Spinal Anesthesia.

BACKGROUND Despite the high frequency of hypotension during spinal anesthesia with proper sedation, no previous report has compared the hemodynamic effects of dexmedetomidine and midazolam sedation during spinal anesthesia. We compared the effects of bispectral index (BIS)-guided intravenous sedation using midazolam or dexmedetomidine on hemodynamics and recovery profiles in patients who underwent spinal anesthesia. MATERIAL AND METHODS One hundred and sixteen adult patients were randomly assigned to receive either midazolam (midazolam group; n=58) or dexmedetomidine (dexmedetomidine group; n=58) during spinal anesthesia. Systolic, diastolic, and mean arterial pressures; heart rates; peripheral oxygen saturations; and bispectral index scores were recorded during surgery, and Ramsay sedation scores and postanesthesia care unit (PACU) stay were monitored. RESULTS Hypotension occurred more frequently in the midazolam group (P<0.001) and bradycardia occurred more frequently in the dexmedetomidine group (P<0.001). Mean Ramsay sedation score was significantly lower in the dexmedetomidine group after arrival in the PACU (P=0.025) and PACU stay was significantly longer in the dexmedetomidine group (P=0.003). CONCLUSIONS BIS-guided dexmedetomidine sedation can attenuate intraoperative hypotension, but induces more bradycardia, prolongs PACU stay, and delays recovery from sedation in patients during and after spinal anesthesia as compared with midazolam sedation.

Comparison of Difference in Hematologic and Hemodynamic Outcomes between Primary Total Knee Arthroplasty and Revision of Infected Total Knee Arthroplasty.

PURPOSE: This study is to identify preoperative cautions for revision of infected total knee arthroplasty (TKA) by understanding the differences in hematologic and hemodynamic changes between primary TKA and revision of infected TKA. MATERIALS AND METHODS: The study included 40 patients in each of the two groups: one group with patients who underwent TKA and the other group with patients who underwent revision of infected TKA. All patients matched for age and body mass index. The following data were compared between the groups: changes in blood pressure, variations in hemoglobin level, amount of postoperative blood loss and transfused blood, incidence of blood transfusion, white blood cell (WBC) count, albumin level, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and liver enzyme level. RESULTS: The hemoglobin levels, transfusion rate, and the amount of blood loss were significantly higher in the revision group (p=0.012). In both groups, CRP reached the highest level on the 3rd postoperative day but it was normalized 2 weeks postoperatively; however, the revision TKA group showed a greater tendency to normalization (p=0.029). There were significant differences between the groups in ESR, WBC, blood pressure, and changes in liver enzyme levels. CONCLUSIONS: Revision of infected TKA results in greater hemodynamic variations than primary TKA. Therefore, more efforts should be made to identify pre- and postoperative hemodynamic changes and hematologic status.

Ultrasound evaluation of the radial artery for arterial catheterization in healthy anesthetized patients.

The purpose of this study was to assess the anatomy of the radial artery using ultrasound in anesthetized patients, and to correlate its anatomical data with patients' characteristics. The success rate of radial artery cannulation using ultrasound was also evaluated to analyze the relationship between the anatomical data and the success rate. Study 1 One hundred ninety-five patients scheduled for general anesthesia were enrolled. Ultrasound measurements were obtained when the vital signs were stable after anesthesia induction. The wrist joint of patients were extended to 30°. The diameter and depth of the radial artery, and the angle between the radial artery and skin surface were measured using ultrasound. Anatomical data were correlated with patients' characteristics. Study 2 Arterial cannulation was performed in 125 patients using long-axis in-plane technique to evaluate the success rate using ultrasound. Study 1 The diameter of the radial artery was mean value of 2.2 ± 0.4 mm and larger than 0.9 mm in all patients. It had significant correlation with body surface area (BSA) (Pearson correlation 0.292, P < 0.001). The incidence of abnormal angle between the radial artery and skin surface was significantly higher in elderly patients (≥65 years) than young patients (P = 0.017). Study 2 The first attempt success rate of arterial catheterization using ultrasound was 92.5 % using long-axis in-plane technique, regardless of patient's characteristics. For small sized adult patients, a 22G angio-catheter should be used during radial artery cannulation, because the radial artery diameter significantly correlated with BSA in healthy anesthetized patients. In addition, ultrasound-guided catheterization is recommended in elderly patients because the incidence of abnormal angle between the radial artery and skin surface was high.

Challenges in fingertip replantation.

Fingertip amputation is a challenging injury to manage. Among various reconstructive procedures, replantation results in superior outcome, but is seldom considered in many institutions. From the identification of vessel ends to reanastomosis of the submillimeter vessels, fingertip's highly specialized anatomy requires technical excellence. By addressing these anatomic challenges, fingertip replantation can be a routine reconstructive option for microvascular surgeons.

The clinical effective dose of rocuronium for lightwand tracheal intubation after induction with alfentanil, propofol, and low concentrations of sevoflurane.

BACKGROUND: The aim of this study was to determine the clinical effective dose of rocuronium for tracheal intubation using a lightwand after induction with propofol, alfentanil, and a low concentration of sevoflurane. METHODS: Twenty-eight adults scheduled to undergo elective surgery lasting less than one hour were enrolled in this study. All patients received alfentanil (10 microg/kg) and propofol (1.5 mg/kg) for the induction of anesthesia. Tracheal intubation using a lightwand was attempted 3 minutes after administering rocuronium and mask ventilation with 2 vol% of sevoflurane. The initial rocuronium dose was 0.5 mg/kg. The rocuronium dose for consecutive patients, determined by Dixon's up-and-down method, was increased or decreased by 0.05 mg/kg according to the result of the previous patient. The mean arterial pressure and heart rate were recorded before induction, 1 min before intubation, 1 and 2 min after intubation. RESULTS: The 50% clinical effective dose (cED(50)) of rocuronium for tracheal intubation using a lightwand was 0.20 +/- 0.05 mg/kg according to Dixon's up and down method. Isotonic regression revealed the cED(50) and cED(95) (95% confidence intervals) to be 0.20 mg/kg (0.10-0.3 mg/kg) and 0.35 mg/kg (0.16-0.49 mg/kg), respectively. CONCLUSIONS: The cED(50) and cED(95) of rocuronium for tracheal intubation using the lightwand were 0.20 mg/kg and 0.35 mg/kg, respectively, after induction with alfentanil, propofol, and a low concentration of sevoflurane.

The radial artery superficial palmar branch flap: a modified free thenar flap with constant innervation.

The free thenar flap is useful for coverage of volar finger defects but has an inconstant innervation based on the presence of either the lateral antebrachial cutaneous nerve (LABC) or the superficial sensory branch of the radial nerve (SSRN). A detailed anatomic study on 30 adult fresh frozen cadavers preinjected with silicone rubber compound to demarcate arterial anatomy documented locations, numbers, and diameters of arteries and skin perforators with surrounding nerves. The palmar cutaneous branch of the median nerve (PCMN) was present within the flap in all cases. However, the LABC and the SSRN were available in only 43.33% and 46.66%, respectively, with neither of them in 33.33% of the cases. The constantly present PCMN allowed the design of a new flap named the radial artery superficial palmar branch (RASP) flap. The RASP flap is large enough to cover volar finger defects and contain direct skin perforators. Because it is constantly innervated, it is an excellent option for coverage of volar finger defects extending to the fingertips.

The effect of oral and IV ramosetron on postoperative nausea and vomiting in patients undergoing gynecological laparoscopy with total intravenous anesthesia.

PURPOSE: Ramosetron can be administered orally as well as intravenously. We investigated the effect of oral ramosetron on postoperative nausea and vomiting (PONV) in patients undergoing gynecological laparoscopy. METHODS: One hundred and twenty women were allocated randomly to one of three groups (n = 40 in each) to receive saline (control), 0.1 mg oral ramosetron (PO), or 0.3 mg IV ramosetron (IV). Total intravenous anesthesia (TIVA) with propofol and remifentanil was used in all patients. RESULTS: The incidence of complete response (no PONV, no rescue) in the control, IV, and PO groups was: 65%, 90%, and 87.5%, respectively, during the first 1 h; and 67.5%, 87.5%, and 80%, respectively, during 1 to 24 h. CONCLUSION: The effect of oral ramosetron 0.1 mg was comparable to that of IV ramosetron 0.3 mg on the prevention of PONV in women undergoing gynecological laparoscopy with TIVA. Both the oral and IV forms were effective at preventing PONV during the first 1 h after surgery.

Stewart's physicochemical approach in neurosurgical patients with hyperchloremic metabolic acidosis during propofol anesthesia.

There is both in vitro and clinical evidence that high-dose propofol can inhibit mitochondrial respiration, resulting in metabolic acidosis. The purpose of this study was to evaluate the effects of propofol anesthesia on the acid-base status in neurosurgical patients with large amount of normal saline administration. Thirty patients undergoing clipping of cerebral aneurysm were randomly assigned to receive propofol (n=15) or isoflurane (n=15). Propofol dose (mean+/-standard error) infused for maintenance was 5.7+/-0.2 mg/kg/h in propofol group. Acid-base parameters such as PaCO2, pH, serum bicarbonate concentration, standard base excess, serum electrolyte concentration, total protein, albumin, lactate, and phosphate were measured before and 4 hours after the induction of anesthesia, and after surgery. The apparent strong ion difference (SIDa), the effective SID (SIDe), and the amount of weak plasma acid were calculated using the Stewart equation. There were no significant differences in pH, PaCO2, bicarbonate, and lactate between 2 groups throughout the whole investigation period. After surgery, standard base excess significantly decreased in both groups without intergroup difference. SIDa and SIDe significantly decreased in both groups, and lactate and strong ion gap significantly increased after surgery in propofol group, but there were no significant differences between 2 groups. Both propofol and isoflurane were associated with hyperchloremic metabolic acidosis in neurosurgical patients with large amount of normal saline administration. The acid-base balance between the 2 anesthetics was similar using Stewart's physicochemical approach.

Alginate/PEI/DNA polyplexes: a new gene delivery system.

AIM: To avoid the limitation of the use of cationic polyethlenimine (PEI)-complexed plasmid DNA use for in vitro or in vivo gene delivery due to its cytotoxicity and lower efficiency in the presence of serum. METHODS: A polyplex with decreased positive charge on the complex surface was designed. The PEI/DNA (PD) complexes coated with an anionic biodegradable polymer, alginate were prepared and their gene delivery behavior with PD was compared. RESULTS: The alginate-coated PD polyplex, where alginate : PEI : DNA [alginate : DNA, 0.15 (w/w); PEI : DNA, N : P = 10] showed about 10 - 30 fold-increased transfection efficiency compared to corresponding non-coated complexes to C3 cells in the presence of 50% serum. The surface charge of the alginate-coated complex was approximately half of that of the alginate-lacking complex. The size of alginate-coated complex was slightly smaller than that of the corresponding complex without alginate. The former complex also showed a reduced erythrocyte aggregation activity and decreased cytotoxicities to C3 cells in comparison with PD complex. CONCLUSION: The alginate-coated PD polyplexes as a new gene delivery system can improve transfection efficiency in high serum concentration with low cytotoxicity to C3 cells.