Pharmacodynamic analysis of intravenous bolus remimazolam for loss of consciousness in patients undergoing general anaesthesia: a randomised, prospective, double-blind study.

BACKGROUND: Remimazolam is a new rapid offset benzodiazepine used for procedural sedation and general anaesthesia. This study evaluated the efficacy and safety of i.v. bolus remimazolam during induction of anaesthesia. METHODS: A total of 120 patients undergoing general anaesthesia were randomly allocated into six dose groups (n=20) of i.v. bolus remimazolam (0.02-0.27 mg kg-1). Loss of consciousness, respiratory depression, patient state index (PSI), and haemodynamic variables were evaluated during anaesthetic induction. Parametric time-to-event models were used to identify the 50% effective dose (ED50)/95% effective dose (ED95) associated with loss of consciousness and respiratory depression. Non-linear mixed-effect models analysed the PSI and haemodynamic changes after i.v. bolus remimazolam. RESULTS: Loss of consciousness and respiratory depression onset showed steep dose-responses with ED50/ED95 of 0.11/0.19 and 0.14/0.27 mg kg-1 and Hill coefficients of 5.3 and 4.6, respectively. Older age was significantly associated with lower ED50/ED95 for both endpoints. ED50/ED95 and the Hill coefficient of PSI decline were 0.12/0.68 mg kg-1 and 1.7, respectively. We propose optimal doses of 0.25-0.33, 0.19-0.25, and 0.14-0.19 mg kg-1 in patients aged <40, 60-80, and >80 yr, respectively, based on the ED95 estimates for the corresponding age groups. The maximum percentage reduction of MAP was 27.8% and the ED50/ED95 were 0.14/2.60 mg kg-1. The effect of remimazolam on heart rate was insignificant. CONCLUSIONS: The ED50/ED95s of i.v. bolus remimazolam were successfully estimated from the time to loss of consciousness and respiratory depression. No serious adverse events occurred within the range of tested doses. CLINICAL TRIAL REGISTRATION: NCT04901871.

Effect of chlorpheniramine administration on postoperative catheter-related bladder discomfort in patients undergoing transurethral excision of bladder tumor: a prospective randomized study.

PURPOSE: Catheter-related bladder discomfort (CRBD) is postoperative distress caused by a urinary catheter. CRBD is related to muscarinic receptor activation. Chlorpheniramine has antimuscarinic properties. Hence, this investigation was undertaken to evaluate the efficacy of chlorpheniramine in preventing CRBD in patients undergoing transurethral resection of bladder tumor (TURBT). METHODS: Seventy-six patients scheduled for TURBT under general anesthesia were assigned into two groups. In the chlorpheniramine group (n = 38), 100 ml normal saline containing 0.1 mg/kg chlorpheniramine was infused after general anesthesia induction. In the control group (n = 38), 100 ml normal saline alone was infused. The incidence and severity of CRBD were assessed at 1, 6, and 24 h postoperatively. RESULTS: The 1-h postoperative incidence of CRBD was lower in the chlorpheniramine group based on the unadjusted analysis [16 (42%) vs. 28 (74%), risk difference 32%, 95% confidence interval 8-51, p = 0.005]. After adjusting the size of the urinary catheter, post hoc analysis showed that the 1-h postoperative incidence of CRBD was lower in the chlorpheniramine group (p = 0.004). The CRBD severity score was lower in the chlorpheniramine group at 1 and 6 h after operation based on the unadjusted analysis (p = 0.012 and p = 0.007, respectively). After adjusting the urinary catheter size, post hoc analysis showed that 1- and 6-h CRBD severity score was lower in the chlorpheniramine group (p = 0.012 and p = 0.008, respectively). The incidence of rescue medication was lower in the chlorpheniramine group [10 (26%) vs. 20 (53%), risk difference 26%, 95% confidence interval 3-47, p = 0.019]. The overall incidence of complications such as nausea, vomiting, dry mouth, flushing, dizziness, and blurred vision was comparable between the two groups. CONCLUSIONS: Chlorpheniramine administration significantly reduces the incidence and severity of CRBD in the patients undergoing TURBT. TRIAL REGISTRATION: KCT0004880 ( https://cris.nih.go.kr/ ).

Two-handed jaw thrust decreases postoperative sore throat in patients undergoing double-lumen endobronchial intubation: A randomised study.

BACKGROUND: Tracheal intubation using a double-lumen endobronchial tube (DLT) causes postoperative sore throat. OBJECTIVE: To determine the effect of two-handed jaw thrust on postoperative sore throat in patients requiring insertion of a DLT. DESIGN: A randomised study. SETTING: A tertiary teaching hospital from December 2017 to May 2018. PATIENTS: One-hundred and six patients undergoing one-lung anaesthesia. INTERVENTIONS: Patients were allocated to one of two groups (n=53 each). In the jaw thrust group, the two-handed jaw thrust manoeuvre was applied at intubation and advancement of the DLT. In the control group, conventional intubation with a sham jaw thrust was performed. MAIN OUTCOME MEASURES: Incidence of sore throat at 1, 6 and 24 h postoperatively. RESULTS: The incidence of sore throat at 6 h postoperatively was higher in the control group than in the jaw thrust group [31 (59%) vs. 14 (26%), risk ratio (95% confidence interval) 0.45 (0.27 to 0.75), P < 0.01]. The overall incidence of sore throat was higher in the control group than in the jaw thrust group [35 (66%) vs. 18 (34%), risk ratio (95% confidence interval) 0.51 (0.34 to 0.78), P < 0.01]. CONCLUSION: The jaw thrust manoeuvre can reduce the incidence of sore throat in patients undergoing DLT insertion for one-lung ventilation. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03331809.

Influence of intraoperative sevoflurane or desflurane on postoperative sore throat: a prospective randomized study.

PURPOSE: Tracheal intubation for general anesthesia causes postoperative sore throat. The purpose of this study was to evaluate the effect of sevoflurane and desflurane on prevalence of postoperative sore throat in patients after general anesthesia. METHODS: Ninety-six patients scheduled for orthopedic lower extremity surgery under general anesthesia were assigned to sevoflurane group or desflurane group. In the sevoflurane group (n = 48), sevoflurane was used as a maintenance anesthetic agent. In the desflurane group (n = 48), desflurane was used. Prevalence of sore throat, number of patients with rescue analgesics, and analgesics requirements were evaluated. RESULTS: The overall prevalence of postoperative sore throat in the sevoflurane group was lower than that in the desflurane group [21 (44%) vs. 32 (67%), p = 0.024]. The prevalence of sore throat at postoperative 4 h in the sevoflurane group was lower than that in the desflurane group [6 (13%) vs. 18 (38%), p = 0.005]. The number of patients requiring rescue analgesics was lower in the sevoflurane group [25 (52%) vs. 36 (75%), p = 0.020]. The requirement of diclofenac was also lower in the sevoflurane group (30 ± 37 mg vs. 47 ± 40 mg, p = 0.031). CONCLUSIONS: We have shown that sevoflurane was associated with less frequent sore throat than desflurane in patients undergoing orthopedic lower extremity surgery.

Air-Water Interfacial Properties of Chloroform-Spread versus Water-Spread Poly((d,l-lactic acid- co-glycolic acid)- block-ethylene glycol) (PLGA-PEG) Polymers.

Polymers at fluid interfaces are used for a number of applications that include coatings, electronics, separation, energy, cosmetics, and medicines. Here, we present a study on an amphiphilic block copolymer, poly((d,l-lactic acid- co-glycolic acid)- block-ethylene glycol) (PLGA-PEG), at the air-water interface. PLGA-PEG at the air-water interface prepared by using an organic spreading solvent exhibits an extremely high surface pressure without the occurrence of desorption, making it an attractive candidate for a variety of uses in the areas mentioned above. The origin of this high surface pressure increase was shown to be due to the glass transition of the PLGA segments. The temperature at which this glass transition occurs for the PLGA segments of PLGA-PEG at the air-water interface was measured to be about 290 K by thermodynamic analysis based on the two-dimensional Maxwell relations. However, from an applications standpoint, spreading by an organic solvent greatly limits its scope of feasible uses. To explore the possibility of maintaining the excellent surface mechanical properties of the PLGA-PEG at the air-water interface while not using an organic solvent, we investigated the air-water interfacial properties of water-spread PLGA-PEG. When spread with water, it was shown that the initial micelles that form in the aqueous spreading solution remain intact even after being spread onto the air-water interface. Due to this different morphology, the surface pressure and monolayer stability were greatly reduced for the water-spread PLGA-PEG at the air-water interface. We used the Daoud and Cotton's blob scaling model to describe the desorption process of the water-spread PLGA-PEG at the air-water interface. From the scaling concept, it was shown that with higher PEG molecular weight and larger micelle size, the adsorption energy of the water-spread PLGA-PEG to the air-water interface was increased.

Increased humidity can soften glassy Langmuir polymer films by two mechanisms: plasticization of the polymer material, and suppression of the evaporation cooling effect.

Glassy Langmuir polymer films exhibit a rapid increase in surface pressure at high compression. High relative humidity typically mitigates this increase in surface pressure. In an attempt to understand the origin of this phenomenon, we investigated the effects of relative humidity on surface pressure-area isotherm properties for four different types of polymers with similar bulk glass transition temperatures: poly(d,l-lactic-co-glycolic acid) (PLGA, Tg ≈ 45 °C), poly(vinyl acetate) (PVAc, Tg ≈ 41 °C), poly(n-propyl methacrylate) (PnPMA, Tg ≈ 41 °C), and poly(vinyl stearate) (PVS, Tg ≈ 47 °C, Tm ≈ 47 °C). Bulk PLGA and PVAc materials are slightly hygroscopic, although they are insoluble in water; the bulk glass transition temperatures of these polymers are decreased under high humidity conditions. Analogously, the surface pressures of Langmuir PLGA and PVAc films become significantly reduced under high relative humidity, which can, therefore, be attributed mainly to the plasticizing effect of humidity on the polymer. X-ray reflectivity (XR) measurements suggest that humidity, however, does not significantly affect the molecular-level structure of the Langmuir polymer film. Interestingly, in the case of PnPMA, although its bulk glass transition temperature is unaffected by humidity levels, Langmuir films formed from PnPMA show significantly decreased surface pressures at high humidity conditions. We confirmed that this result is not an artifact associated with surface pressure measurements; humidity does not influence the wetting characteristics of the Wilhelmy probe at the air-polymer-water interface. It appears that the humidity-dependent behavior of Langmuir PnPMA films can only be explained in terms of the effects of relative humidity on the rate of water evaporation and thus the temperature at the surface of the polymer film; high humidity suppresses the evaporation of water and thus increases the temperature of the polymer-coated interface, resulting in a softening of the polymer film. We experimentally confirmed that increasing the relative humidity from about 30-40% to about 85-90% has an equivalent effect on PnPMA surface pressure as increasing the temperature of the system by about 2 °C. A heat and mass transfer analysis supports this correspondence. Langmuir PVS films exhibit a completely different behavior than PLGA, PVAc and PnPMA systems; PVS forms isolated two-dimensional crystalline domains at the air-water interface, and their surface pressure-area behavior is commensurate to that of colloidal particles spread at the air-water interface. Humidity seems to affect the surface pressure of PVS through a mechanism similar to the PnPMA situation.

Effects of calcium chloride coadministered with neostigmine on neuromuscular blockade recovery: A double-blind randomised study.

BACKGROUND: Ionised calcium plays an important role in neuromuscular transmission, but its effects on the reversal of nondepolarising neuromuscular blockade have not been fully evaluated. OBJECTIVE: We examined whether calcium chloride coadministered with neostigmine could enhance the rate of neuromuscular recovery. DESIGN: Randomised double-blind trial. SETTING: A tertiary teaching hospital. PATIENTS: In total, 53 patients undergoing elective surgery under general anaesthesia with neuromuscular monitoring by acceleromyography using a TOF-Watch SX monitor. INTERVENTIONS: Patients were randomly allocated to receive either 5 mg kg of calcium chloride (calcium group, n = 26) or the same volume of normal saline (control group, n = 27) coadministered with 25 µg kg of neostigmine and 15 µg kg of atropine at the end of surgery. MAIN OUTCOME MEASURES: The primary end point was the neuromuscular recovery time [time from neostigmine administration to recovery of the TOF ratio (TOFr) to 0.9]. Secondary end points included the TOFr at 5, 10 and 20 min after neostigmine administration and the incidence of postoperative residual curarisation (PORC), defined as a TOFr less than 0.9 at each time point. RESULTS: The neuromuscular recovery time was significantly faster in the calcium group than in the control group (median [Q1 to Q3]; 5.0 [3.0 to 7.0] vs. 6.7 [5.7 to 10.0] min, respectively; P = 0.007). At 5 min after neostigmine administration, the TOFr was higher [87 (74 to 100) vs. 68 (51 to 81)%, respectively; P = 0.002] and the incidence of PORC was lower (50.0 vs. 81.5%, respectively; P = 0.016) in the calcium group than in the control group. There were no differences between the two groups with respect to the TOFr or incidence of PORC at 10 and 20 min after neostigmine administration. CONCLUSION: Calcium chloride coadministered with neostigmine enhanced neuromuscular recovery in the early period of nondepolarising neuromuscular blockade reversal.

Intrathecal morphine for postoperative pain control following robot-assisted prostatectomy: a prospective randomized trial.

PURPOSE: Robot-assisted laparoscopic prostatectomy (RALP) is minimally invasive surgery, but also causes moderate to severe pain during the immediate postoperative period. We evaluated the efficacy and safety of intrathecal morphine (ITM) for postoperative pain control in patients undergoing RALP. METHODS: Thirty patients scheduled for RALP were randomly assigned into one of two groups. In the ITM group (n = 15), postoperative pain was managed using 300 µg intrathecal morphine with intravenous patient-controlled analgesia (IV-PCA). In the IV-PCA group (n = 15), only intravenous patient-controlled analgesia was used. The numerical pain score (NPS; 0 = no pain, 100 = worst pain imaginable), postoperative IV-PCA requirements and opioid-related complications including nausea, vomiting, dizziness, headache and pruritus were compared between the two groups. RESULTS: The NPSs on coughing were 20 (IQR 10-50) in the ITM group and 60 (IQR 40-80) in the IV-PCA group at postoperative 24 h (p = 0.001). The NPSs were significantly lower in the ITM group up to postoperative 24 h. The ITM group showed less morphine consumption at postoperative 24 h in the ITM group than in the IV-PCA group [5 (IQR 3-15) mg vs 17 (IQR 11-24) mg, p = 0.001]. Complications associated with morphine were comparable between the two groups and respiratory depression was not reported in either group. CONCLUSION: Intrathecal morphine provided more satisfactory analgesia without serious complications during the early postoperative period in patients undergoing RALP.

Combined intraoperative paracetamol and preoperative dexamethasone reduces postoperative sore throat: a prospective randomized study.

PURPOSE: Postoperative sore throat (POST) after general anesthesia with endotracheal intubation is a common and undesirable complication. In this study, we evaluated the combined effects of paracetamol and dexamethasone on the prevention of POST in patients after general anesthesia. METHODS: A total of 226 patients scheduled for urologic surgery under general anesthesia were randomly assigned to one of two groups. In the DexaPara group (n = 113), dexamethasone (10 mg) and paracetamol (1000 mg) was infused. In the Dexa group (n = 113), dexamethasone (10 mg) alone was given. POST, hoarseness, and dysphagia were monitored. The postoperative wound pain score and perioperative opioid requirements were compared. In addition, complications related to opioids were compared between the groups. RESULTS: The overall incidence of POST was lower in the DexaPara group than in the Dexa group [42 (37%) vs. 72 (64%), p < 0.001]. The incidence of POST while resting at postoperative 1 and 6 h was lower in the DexaPara group than in the Dexa group (p = 0.008 and p = 0.004, respectively). The incidence of postoperative nausea, vomiting, drowsiness, shivering, and headache was comparable between the groups. CONCLUSIONS: Paracetamol and dexamethasone infusion reduced the incidence of POST without serious complications in patients for urologic surgery under general anesthesia.

Influence of caudal traction of ipsilateral arm on ultrasound image for supraclavicular central venous catheterization.

BACKGROUND: The first step for successful ultrasound (US)-guided subclavian vein (SCV) catheterization using a supraclavicular approach is to obtain a good longitudinal image of SCV for in-plane needle placement. We evaluated the efficacy of caudal traction of ipsilateral arm on the exposure of the SCV. METHODS: We enrolled 20 infants, 20 children, and 20 adults undergoing general anesthesia. After tracheal intubation, US probe was applied as the supraclavicular approach, and the longitudinal US image of SCV was obtained in 3 different ipsilateral arm positions: neutral, caudal traction, and abduction. The length of puncturable SCV, the diameter of SCV, and the available angle for needle insertion in 3 different arm positions were analyzed. RESULTS: In all patients, the length of puncturable SCV and the available angle for needle insertion were significantly increased after caudal traction (35.6% ± 27.1% and 25.0% ± 19.3%, respectively) and decreased after the abduction (36.6% ± 22.9% and 29.5% ± 23.8%, respectively) compared to neutral position. The diameter of SCV was not changed after applying the caudal traction in infants and children. However, in adults, the caudal traction slightly increased the diameter of SCV (P = .012). CONCLUSION: The caudal traction of ipsilateral arm toward to the knee improves the longitudinal US view of SCV for the supraclavicular approach, without reducing its size. Proper caudal traction of the arm might ensure the high success rate with safe needle insertion technique. Abduction should be avoided during US-guided supraclavicular SCV catheterization.

The effect of sevoflurane versus desflurane on postoperative catheter-related bladder discomfort in patients undergoing transurethral excision of a bladder tumour: a randomized controlled trial.

PURPOSE: Catheter-related bladder discomfort (CRBD) due to an indwelling urinary catheter can cause postoperative distress, and the mechanism underlying CRBD is linked to the activation of muscarinic receptors. Inhalation of anesthetic agents, such as sevoflurane and desflurane, has differential inhibitory effects on muscarinic receptors. We aimed to compare the effect of intraoperative sevoflurane vs desflurane inhalation on postoperative CRBD. METHODS: Eighty-nine patients undergoing transurethral resection of a bladder tumour (TURBT) were randomly allocated to two groups. The sevoflurane group (n = 45) and the desflurane group (n = 44) received the respective inhalational agents for maintenance of general anesthesia. The incidence and severity (mild/moderate/severe) of CRBD were assessed at zero, one, six, and 24 hr postoperatively. RESULTS: Catheter-related bladder discomfort during the first 24 hr postoperatively occurred in 34/45 (76%) patients receiving sevoflurane compared with 41/44 (93%) patients receiving desflurane [absolute difference 18%; 95% confidence interval [CI], 2 to 33; P = 0.039]. The differences in the rate of CRBD between the sevoflurane and desflurane groups at zero, one, and six hours postoperatively were 24% (95% CI, 7 to 40; P = 0.012), 33% (95% CI, 15 to 49; P = 0.001), and 26% (95% CI, 6 to 43; P = 0.019), respectively. The incidence of moderate to severe CRBD and the number of patients treated with tramadol for CRBD were comparable between the two groups. CONCLUSIONS: As a maintenance agent of general anesthesia, sevoflurane reduced the incidence of early postoperative CRBD in patients undergoing TURBT when compared with desflurane. The protocol for this clinical trial was registered at ClinicalTrials.gov (NCT02096224).

Surface Mechanical and Rheological Behaviors of Biocompatible Poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) and Poly((D,L-lactic acid-ran-glycolic acid-ran-ε-caprolactone)-block-ethylene glycol) (PLGACL-PEG) Block Copolymers at the Air-Water Interface.

Air-water interfacial monolayers of poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) exhibit an exponential increase in surface pressure under high monolayer compression. In order to understand the molecular origin of this behavior, a combined experimental and theoretical investigation (including surface pressure-area isotherm, X-ray reflectivity (XR) and interfacial rheological measurements, and a self-consistent field (SCF) theoretical analysis) was performed on air-water monolayers formed by a PLGA-PEG diblock copolymer and also by a nonglassy analogue of this diblock copolymer, poly((D,L-lactic acid-ran-glycolic acid-ran-caprolactone)-block-ethylene glycol) (PLGACL-PEG). The combined results of this study show that the two mechanisms, i.e., the glass transition of the collapsed PLGA film and the lateral repulsion of the PEG brush chains that occur simultaneously under lateral compression of the monolayer, are both responsible for the observed PLGA-PEG isotherm behavior. Upon cessation of compression, the high surface pressure of the PLGA-PEG monolayer typically relaxes over time with a stretched exponential decay, suggesting that in this diblock copolymer situation, the hydrophobic domain formed by the PLGA blocks undergoes glass transition in the high lateral compression state, analogously to the PLGA homopolymer monolayer. In the high PEG grafting density regime, the contribution of the PEG brush chains to the high monolayer surface pressure is significantly lower than what is predicted by the SCF model because of the many-body attraction among PEG segments (referred to in the literature as the "n-cluster" effects). The end-grafted PEG chains were found to be protein resistant even under the influence of the "n-cluster" effects.

Humidity-dependent compression-induced glass transition of the air-water interfacial Langmuir films of poly(D,L-lactic acid-ran-glycolic acid) (PLGA).

Constant rate compression isotherms of the air-water interfacial Langmuir films of poly(D,L-lactic acid-ran-glycolic acid) (PLGA) show a distinct feature of an exponential increase in surface pressure in the high surface polymer concentration regime. We have previously demonstrated that this abrupt increase in surface pressure is linked to the glass transition of the polymer film, but the detailed mechanism of this process is not fully understood. In order to obtain a molecular-level understanding of this behavior, we performed extensive characterizations of the surface mechanical, structural and rheological properties of Langmuir PLGA films at the air-water interface, using combined experimental techniques including the Langmuir film balance, X-ray reflectivity and double-wall-ring interfacial rheometry methods. We observed that the mechanical and structural responses of the Langmuir PLGA films are significantly dependent on the rate of film compression; the glass transition was induced in the PLGA film only at fast compression rates. Surprisingly, we found that this deformation rate dependence is also dependent on the humidity of the environment. With water acting as a plasticizer for the PLGA material, the diffusion of water molecules through the PLGA film seems to be the key factor in the determination of the glass transformation properties and thus the mechanical response of the PLGA film against lateral compression. Based on our combined results, we hypothesize the following mechanism for the compression-induced glass transformation of the Langmuir PLGA film; (1) initially, a humidified/non-glassy PLGA film is formed in the full surface-coverage region (where the surface pressure shows a plateau) during compression; (2) further compression leads to the collapse of the PLGA chains and the formation of new surfaces on the air side of the film, and this newly formed top layer of the PLGA film is transiently glassy in character because the water evaporation rate in the top surface region is momentarily faster than the humidification rate (due to the initial roughness of the newly formed surface); (3) after some time, the top layer itself becomes humidified through diffusion of water from the subphase, and thus it becomes non-glassy, leading to the relaxation of the applied compressive stress.

Comparison of the endotracheal tube cuff pressure between a tapered- versus a cylindrical-shaped cuff after changing from the supine to the lateral flank position.

PURPOSE: Positional change can displace an endotracheal tube (ETT) and change the ETT cuff pressure in a tracheally intubated patient. Endotracheal tubes with different cuff shapes may lead to different cuff pressures after positional change. We hypothesized that the intracuff pressure in the TaperGuard™ ETT with a tapered-shaped cuff would be higher than that in the conventional ETT with a cylindrical-shaped cuff after a change from the supine to the lateral flank position. METHODS: Fifty-eight patients scheduled for open urological procedures in the lateral flank position were randomly allocated to receive either a TaperGuard ETT (group T) or conventional ETT (group C). The ETT cuff pressure was initially set at 20 cm H2O in the supine position and was measured after the change to the lateral flank position. The distance from the ETT tip to the carina was measured in both the supine and the lateral flank positions. RESULTS: Two patients, one from each group, were excluded from the data analysis. The mean (SD) ETT cuff pressure was significantly higher in group T (n = 28) than in group C (n = 28) after the change in position [31 (7) cm H2O vs 25 (4) cm H2O, respectively; mean difference, 6 cm; 95% confidence intervals [CI], 3 to 9; P < 0.001]. The mean (SD) proximal migration of the ETT tip was comparable between the two groups [8 (18) mm vs 4 (14) mm, respectively; P = 0.367]. CONCLUSIONS: After the change from the supine to the lateral flank position, the ETT cuff pressure was significantly higher in the TaperGuard ETT than in the conventional ETT, although the extent of cephalad displacement of the ETT was comparable between the two groups. This trial was registered at Clinicaltrials.gov: NCT02165319.

The effect of intraoperative dexmedetomidine on postoperative catheter-related bladder discomfort in patients undergoing transurethral bladder tumour resection: A double-blind randomised study.

BACKGROUND: Catheter-related bladder discomfort (CRBD) due to an indwelling urinary catheter causes postoperative distress. Dexmedetomidine is used as an anaesthetic adjuvant during general anaesthesia and has an antimuscarinic effect, which may be beneficial for the prevention and treatment of CRBD. OBJECTIVE: To determine the effect of intraoperative dexmedetomidine administration on the incidence of CRBD. DESIGN: A double-blind, placebo-controlled, randomised study. SETTING: A tertiary care teaching hospital. PATIENTS: One-hundred and nine patients undergoing transurethral bladder tumour excision (TURB). INTERVENTIONS: Patients were randomly allocated to two groups: control group (n = 55) received placebo and dexmedetomidine group (n = 54) received intraoperative dexmedetomidine (1 µg kg(-1) loading dose followed by 0.5 µg kg(-1) h(-1) continuous infusion). MAIN OUTCOME MEASURES: The incidence and severity (mild, moderate, severe) of CRBD assessed at 0, 1, 6 and 24 h postoperatively. RESULTS: The incidence of CRBD was significantly higher in the control group at 0 (78 vs. 50%; P = 0.004), 1 (86 vs. 57%; P = 0.002) and 6 h (82 vs. 63%; P = 0.047) postoperatively. The incidence of moderate to severe CRBD was higher in the control group at 0 (38 vs. 11%; P = 0.002) and 1 h (29 vs. 7%; P = 0.006) postoperatively. The number of patients having CRBD treated with tramadol was higher in the control group (24 vs. 12; P = 0.006). The mean end-tidal desflurane concentration during the surgery was higher in the control group (4.5 vs. 3.9%; P = 0.04). The postoperative pain score (numerical rating scale: 0 to 10) was higher in the control group at 0 (4.6 vs. 2.7; P = 0.002), and 1 h (3.8 vs. 2.7; P = 0.041). The number of patients treated with opioids was higher in the control group (21 vs. 8; P = 0.011). CONCLUSION: Intraoperative dexmedetomidine administration decreased the incidence and severity of early postoperative CRBD as well as intraoperative desflurane and postoperative opioid requirements in patients undergoing TURB. TRIAL REGISTRATION IDENTIFIER: NCT01991223 (www.clinicaltrials.gov).

Effect of glycopyrrolate versus atropine coadministered with neostigmine for reversal of rocuronium on postoperative catheter-related bladder discomfort in patients undergoing transurethral resection of bladder tumor: a prospective randomized study.

BACKGROUND: Muscarinic receptors are involved in the mechanism of postoperative catheter-related bladder discomfort (CRBD). Glycopyrrolate and atropine as adjuncts to reversal of neuromuscular blockers have differential inhibitory effects on muscarinic receptors. This study was conducted to compare the effect of glycopyrrolate versus atropine on postoperative CRBD in patients undergoing transurethral resection of a bladder tumor (TURBT). METHODS: Seventy-four patients undergoing TURBT were randomly allocated to receive either glycopyrrolate 10 µg/kg (glycopyrrolate group, n = 37) or atropine 15 µg/kg (atropine group, n = 37) in combination with neostigmine 25 µg/kg at the end of surgery for reversal of neuromuscular blockade. The incidence and severity (mild/moderate/severe) of CRBD were assessed at 0, 1, 6, and 24 h postoperatively. Tramadol 50-100 mg was administered intravenously if the patients complained of moderate or severe CRBD. RESULTS: The incidence of CRBD was significantly lower in the glycopyrrolate group than in the atropine group at 0 h (65 % vs. 89 %, p = 0.025) and 1 h (54 % vs. 89 %, p = 0.002) postoperatively. The severity of postoperative CRBD was less severe in the glycopyrrolate group than in the atropine group at 0 h (p = 0.013) and 1 h (p = 0.006). Fewer patients required tramadol in the glycopyrrolate group than in the atropine group (3 % vs. 12 %, p = 0.024). CONCLUSIONS: Glycopyrrolate as an adjunct to reversal of neuromuscular blockers decreased the incidence of early postoperative CRBD and postoperative tramadol requirements in patients undergoing TURBT when compared to atropine.

Quantitative Analysis of the Effect of Neuromuscular Blockade on Motor-Evoked Potentials in Patients Undergoing Brain Tumor Removal Surgery: A Prospective, Single-Arm, Open-Label Observational Study.

Background: We aimed to elucidate the quantitative relationship between the neuromuscular blockade depth and intraoperative motor-evoked potential amplitudes. Methods: This prospective, single-arm, open-label, observational study was conducted at a single university hospital in Seoul, Korea, and included 100 adult patients aged ≥19 years undergoing brain tumor removal surgery under general anesthesia. We measured the neuromuscular blockade degree and motor-evoked potential amplitude in the deltoid, abductor pollicis brevis, tibialis anterior, and abductor hallucis muscles until dural opening. Results: The pharmacokinetic-pharmacodynamic model revealed the exposure-response relationship between the rocuronium effect-site concentration and motor-evoked potential amplitudes. The mean motor-evoked potential amplitudes decreased proportionally with increasing neuromuscular blockade depth. As the mean amplitude increased, the coefficient of variation decreased bi-exponentially. The critical ratio of the first evoked response to the train-of-four stimulation (T1)/control response (Tc) thresholds beyond which the coefficient of variation exhibited minimal change were found to be 0.63, 0.65, 0.68, and 0.63 for the deltoid, abductor pollicis brevis, tibialis anterior, and abductor hallucis muscles, respectively. Conclusions: Our results reveal that the motor-evoked potential amplitude exhibits deterioration proportional to the degree of neuromuscular blockade. In light of the observed bi-exponential decline of the coefficient of variation with the motor-evoked potential amplitude, we recommend maintaining a T1/Tc ratio higher than 0.6 for partial neuromuscular blockade.

Analgesic effects of combined transversus abdominis plane block and intramuscular electrical stimulation in patients undergoing cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy: a randomized controlled trial.

BACKGROUND: To evaluate the analgesic efficacy of a four-quadrant transversus abdominis plane (4QTAP) block and a combination of 4QTAP block with needle electrical twitch and intramuscular electrical stimulation (NETOIMS) in patients undergoing cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC). MATERIALS AND METHODS: Eighty-one patients who underwent CRS followed by HIPEC were included in this study. Patients were randomly assigned to one of three groups: group 1 (intravenous patient-controlled analgesia, control group), group 2 (preoperative 4QTAP block), and group 3 (preoperative 4QTAP block and postoperative NETOIMS). The primary study endpoint was the pain score assessed by the visual analog scale (VAS: 0, no pain; 10, worst imaginable pain) on postoperative day (POD) 1. RESULTS: The VAS pain score on POD 1 was significantly lower in group 2 than in group 1 (6.0±1.7 and 7.6±1.9, P =0.004), whereas that in group 3 was significantly lower than that in groups 1 and 2 ( P <0.001 and P =0.004, respectively). Opioid consumption and nausea and vomiting incidence during POD 7 were significantly lower in group 3 than in groups 1 and 2. Gait speed and peak cough flow on POD 4 and 7, as well as the quality of recovery (QoR)-40 score on POD 4, were significantly higher in group 3 than in groups 1 and 2. CONCLUSIONS: The combination of a 4QTAP block with NETOIMS provided more effective analgesia than a 4QTAP block alone after CRS, followed by HIPEC, and enhanced functional restoration and quality of recovery.