Analgesic efficacy of erector spinae plane block in patients undergoing major gynecologic surgery: A randomized controlled study

STUDY OBJECTIVE

To investigate the analgesic efficacy of erector spinae plane block (ESPB) in major gynecologic surgery, expressed as cumulative opioid consumption 24 h after surgery.

DESIGN

A single-center, patient-assessor blinded, randomized controlled study.

SETTING

Samsung medical center (tertiary university hospital), between February 2022 to January 2023.

PATIENTS

Eighty-eight females undergoing major surgery with long midline incision for gynecologic malignancy.

INTERVENTIONS

Patients were randomly assigned to receive standard systemic analgesia (Control group) or ESPB (ESPB group). ESPB was performed bilaterally at the level of the 9th thoracic vertebra with a mixture of 20 mL of 0.5% ropivacaine and 100 μg of epinephrine.

MEASUREMENTS

The primary outcome was cumulative opioid consumption at 24 h postoperatively. Secondary outcomes included opioid consumption and pain severity during the 72 h after surgery. The variables regarding postoperative recovery and patient-centered outcomes were compared.

MAIN RESULTS

The mean cumulative opioid consumption 24 h after surgery was 35.8 mg in the ESPB group, which was not significantly different from 41.4 mg in the control group (mean difference, 5.5 mg; 95% CI -1.7 to 12.8 mg; P = 0.128). However, patient satisfaction regarding analgesia was significantly higher in the ESPB group compared with the control group at 24 h postoperative (median difference, -1; 95% CI -3 to 0; P = 0.038). There were no significant differences in the variables associated with postoperative recovery.

CONCLUSION

ESPB did not reduce opioid consumption during the 24 h postoperative but attenuated pain intensity during the early period after surgery.

Comparison of analgesic effects between programmed intermittent epidural boluses and continuous epidural infusion after cesarean section: a randomized controlled study

Background

This study aimed to compare the analgesic effects of programmed intermittent epidural boluses (PIEB) and continuous epidural infusion (CEI) for postoperative analgesia after elective cesarean section (CS).

Methods

Seventy-four women who underwent elective CS were randomized to receive either PIEB or CEI. The PIEB group received 4 ml-intermittent boluses of 0.11% ropivacaine every hour at a rate of 120 ml/h. The CEI group received a constant rate of 4 ml/h of 0.11% ropivacaine. The primary outcome was the pain score at rest at 36 h after CS. Secondary outcomes included the pain scores during mobilization, time-weighted pain scores, the incidence of motor blockade, and complications-related epidural analgesia during 36 h after CS.

Results

The pain score at rest at 36 h after CS was significantly lower in the PIEB group compared with that in the CEI group (3.0 vs. 0.0; median difference, 2; 95% CI: 1, 2; P < 0.001). The mean time-weighted pain scores at rest and during mobilizations were also significantly lower in the PIEB group than in the CEI group (pain at rest: mean differences, 37.5; 95% CI, [24.6, 50.4]; P < 0.001; pain during mobilization: mean difference, 56.6; 95% CI, [39.8, 73.5]; P < 0.001). The incidence of motor blockade was significantly reduced in the PIEB group compared with that in the CEI group (P < 0.001).

Conclusion

PIEB provides superior analgesia with less motor blockade than CEI in postpartum women after CS, without any apparent adverse events.

Initial experience with the enhanced recovery after surgery (ERAS) protocols in gynecologic surgery at an urban academic tertiary medical center

Background

The enhanced recovery after surgery (ERAS) protocols have been consistently associated with improved patient experience and surgical outcomes. Despite the release of ERAS Society guidelines specific to gynecologic oncology, the adoption of ERAS in gynecology on global level has been disappointingly low and some centers have shown minimal improvement in clinical outcomes after adopting ERAS. The aim of this study is to describe the development and early experience of ERAS protocols in gynecologic surgery at an urban academic tertiary medical center.

Methods

This was an observational prospective cohort study. The target patient population included those with low comorbidities who were scheduled to undergo various types of gynecologic surgeries for both benign and malignant diseases between October 2020 and February 2021. Two attending surgeons implemented the protocols for their patients (ERAS cohort) while three attending surgeons maintained the conventional perioperative care for their patients (non-ERAS cohort). Baseline characteristics, surgical outcomes and patients' answers to a 12-question survey were compared. A case-matched comparative analysis was also performed between the ERAS cohort and the historical non-ERAS cohort (those who received the same types of surgical procedures from the two ERAS attending surgeons prior to the implementation of the protocols).

Results

A total of 244 patients were evaluated (122 in the ERAS cohort vs. 122 in the non-ERAS cohort). The number of vials of opioid analgesia used during the first two postoperative days was significantly lower whereas the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen was more frequent in the ERAS cohort group. The patients in the ERAS group reported less postoperative pain, feelings of hunger and thirst, and greater amount of exercise postoperatively. These benefits of the ERAS cohort were more pronounced in the patients who underwent laparotomic surgeries than those who underwent laparoscopic surgeries. The case-matched comparative analysis also showed similar results. The length of hospital stay did not differ between those who underwent the ERAS protocols and those who did not.

Conclusions

The results of the study demonstrated the safety, clinical feasibility and benefits of the ERAS protocols for patients undergoing gynecologic surgeries for both benign and malignant indications.

The Effect of Intrathecal Morphine on Postoperative Opioid Consumption in Patients Undergoing Abdominal Surgery for Gynecologic Malignancy: A Randomized Sham-Controlled Trial

BACKGROUND

Surgery for gynecologic malignancy via midline-laparotomy leads to severe postoperative pain. Adequate pain control while sparing opioid consumption does offer benefits in postoperative complications and recovery. Intrathecal morphine (ITM) provides simple and effective analgesia. In this randomized trial, we compared postoperative opioid consumption in patients who received either ITM or a sham procedure.

METHODS

We enrolled 68 adult patients undergoing open gynecologic oncology surgery from June 2021 to November 2021. They were randomly allocated to the ITM group (ITM; 200 μg injection) or sham group (sham procedure) to achieve a final 1:1 ratio between groups. We compared opioid consumption and pain severity during 72 hours after surgery. The variables regarding postoperative recovery and patient-centered outcomes were collected. The primary outcome is cumulative intravenous (IV) opioid consumption 24 hours after surgery.

RESULTS

The median (interquartile range) cumulative IV opioid consumption during 24 hours after surgery was 18 mg (12-29) in the ITM group and 36 mg (27-42) in the sham group (median difference, 13; 95% confidence interval, 7.2-20.7; P < .001). Patient satisfaction regarding pain control was statistically significantly higher in the ITM group than in the sham group at postoperative 24 and 48 hours ( P < .001 and P = .005, respectively). There were no significant differences in the variables associated with postoperative recovery and frequency of complications requiring treatment.

CONCLUSIONS

ITM is a safe and effective analgesic method after curative intent laparotomy for gynecologic malignancy. ITM provides better pain relief, reduces opioid consumption, and improves patient satisfaction without additional evident adverse events.

Long Term Vortex Flow Evolution around a Magnetic Island in Tokamaks

We present a gyrokinetic analysis of the vortex flow evolution in a magnetic island in collisionless tokamak plasmas. In a short term ω[over ¯]_{D}t<1, where ω[over ¯]_{D} is the secular magnetic drift of the orbit center, initial monopolar vortex flow approaches to its residual level determined by the neoclassical enhancement of polarization shielding after collisionless relaxation. The residual level depends on the location inside an island and is higher than the Rosenbluth-Hinton level [M.N. Rosenbluth and F.L. Hinton, Phys. Rev. Lett. 80, 724 (1998)PRLTAO0031-900710.1103/PhysRevLett.80.724] due to finite island width. In a long term ω[over ¯]_{D}t>1, the residual vortex flow evolves to a dipolar zonal-vortex flow mixture due to toroidicity-induced breaking of a helical symmetry. The mixture forms localized flow shear layers near the island separatrix away from X points. The deviation of the streamlines of the mixture flows from magnetic surfaces allows turbulence advection across the island. We expect a small island w≲qρ_{Ti}/s[over ^] provides a favorable condition for this mixture flow formation, while the monopolar vortex flow persists for a larger island.

Intravenous iron injection does not impair liver function in a rat model of cirrhosis

BACKGROUND

There is a lack of convincing data concerning the safety of iron therapy in patients with advanced liver cirrhosis (LC). This study investigated the hepatic effects of ferric carboxymaltose, an intravenous iron supplement, in a rat model of cirrhosis.

METHODS

In total, 45 Sprague-Dawley rats were allocated into three groups: normal rats (control group, n=15), cirrhotic rats receiving intravenous normal saline (LC group, n=15), and cirrhotic rats receiving 20 mg/kg intravenous ferric carboxymaltose (LC-iron group, n=15). LC was induced by twice-weekly intraperitoneal injection of carbon tetrachloride. Biochemical parameters were compared at 0, 2, 14, and 28 days. Additionally, liver tissue samples were extracted from five rats in each group at 2, 14, and 28 days for evaluation of the degrees of hepatic fibrosis and iron deposition. Inflammatory and oxidative stress markers were also compared among groups.

RESULTS

Serum alanine transferase levels did not significantly differ between the LC and LC-iron groups at 0 (443±110 vs. 444±117 IU/L, P>0.99), 2 (453±117 vs. 479±136 IU/L, P=0.84), 14 (1,535±1,058 vs. 1,578±711 IU/L, P=0.55), or 28 days (2,067±641 vs. 2,533±914 IU/L, P=0.15). The degree of hepatic fibrosis was comparable between the groups, although hepatic iron accumulation was greater in the LC-iron group than in the LC group. The levels of inflammatory and oxidative stress markers were significantly lower in the LC-iron group than in the LC group.

CONCLUSIONS

In our rat model of cirrhosis, the administration of intravenous iron appears safe. However, further preclinical and clinical studies are warranted to confirm the safety and efficacy of intravenous iron in patients with LC or end-stage liver disease.

Utility of ultrasound evaluation of I-Gel® placement in children: An observational study

BACKGROUND

Ultrasound is not widely used to evaluate optimal supraglottic airway positioning even though it could potentially be used to identify and correct problem areas.

AIMS

We evaluated a new ultrasound scoring method to identify the position of the supraglottic airway and detect the location of air leaks during ventilation in pediatric patients.

METHODS

Using a prospective observational study design, we enrolled 90 pediatric patients of ASA physical status I-III scheduled for elective surgery under general anesthesia. After anesthesia induction, patients were assigned to a noncorrection group or a correction group after their first ultrasound evaluation. Noncorrection group comprised patients with tolerable I-Gel positioning based on ultrasound evaluation and no problems with clinical parameters, while the correction group comprised patients with I-Gel mispositioning based on ultrasound.

RESULTS

After the first ultrasound evaluation, 61 patients did not need I-Gel correction (noncorrection group), while 29 patients needed I-Gel correction (correction group) and underwent a second ultrasound evaluation. Airway sealing pressure and total ultrasound score showed a negative correlation (r = -.845, p < .001). The area under the receiver operating curve for total ultrasound score was 0.97 (95% confidence interval, 0.94-0.99; p < .001). In the correction group, ultrasound score and ventilation parameters improved after correction based on ultrasound evaluation.

CONCLUSIONS

Ultrasound scores were negatively correlated with airway sealing pressure in pediatric patients. Ultrasound evaluation is useful for detecting misplacement of the I-Gel and can be a useful tool for correction.

Comparison of Jaw Elevation Device vs. Conventional Airway Assist during Sedation in Chronic Kidney Diseases Undergoing Arteriovenous Fistula Surgery: A Randomized Controlled Trial

Patients with chronic renal failure (CRF) are likely to have obstructive sleep apnea (OSA) underdiagnosed, and maintaining airway patency is important during sedation. This study compared Jaw elevation device (JED) with conventional airway interventions (head lateral rotation, neck extension, oral or nasal airway insertion, and jaw thrust maneuver) during sedation and hypothesized that JED may be effective to open the airway. A total of 73 patients were allocated to a conventional group (n = 39) and a JED group (n = 34). The number of additional airway interventions was the primary outcome. Percentage of patients with no need of additional interventions and apnea-hypopnea index (AHI) were secondary outcomes. The number of additional interventions was significantly less in the JED group compared to the conventional group (0 (0–0) vs. 1 (0–2); p = 0.002). The percentage of patients with no requirement for additional interventions was significantly higher in the JED group compared to the conventional group (76.5% vs. 43.6%; p = 0.004). AHI was significantly lower in the JED group compared to the conventional group (4.5 (1.5–11.9) vs. 9.3 (3.8–21.9), p = 0.015). In conclusion, JED seems to be effective in opening the airway patency during sedation in CRF patients.

Effects of plasma turbulence on the nonlinear evolution of magnetic island in tokamak

Magnetic islands (MIs), resulting from a magnetic field reconnection, are ubiquitous structures in magnetized plasmas. In tokamak plasmas, recent researches suggested that the interaction between an MI and ambient turbulence can be important for the nonlinear MI evolution, but a lack of detailed experimental observations and analyses has prevented further understanding. Here, we provide comprehensive observations such as turbulence spreading into an MI and turbulence enhancement at the reconnection site, elucidating intricate effects of plasma turbulence on the nonlinear MI evolution.

Magnetic reconnection and plasma turbulence occur in atmospheric and magnetized laboratory plasmas. Here the authors report evolution of magnetic islands and plasma turbulence in tokamak plasmas using high resolution 2D electron cyclotron emission diagnostics.

Ischemic Preconditioning Protects Against Hepatic Ischemia-Reperfusion Injury Under Propofol Anesthesia in Rats

BACKGROUND

Propofol is widely used in general anesthesia, and it has been reported to protect various organs against ischemia-reperfusion injury (IRI), including liver. To evaluate the hepatoprotective effects of ischemic preconditioning (IP) under propofol anesthesia, we investigated the possible underlying mechanisms in rats.

METHODS

Male Sprague-Dawley rats were randomly assigned to 3 groups: sham group (n = 5), non-IP group (n = 9; 45 minutes of hepatic ischemia followed by 2 hours of reperfusion), and IP group (n = 9; IP applied as 10 minutes of hepatic ischemia followed by 15 minutes of reperfusion before 45 minutes of ischemia). Anesthesia was maintained with intravenous (IV) infusion of propofol (800 μg/kg/min). Liver enzymes, histopathological changes, and cytokine expression were examined.

RESULTS

The IP group showed significantly lower liver enzyme levels (aspartate aminotransferase, P = .045; alanine aminotransferase, P = .006) and reduced the histologic grades of hepatic injury 2 hours after reperfusion (P = .004) compared to the non-IP group. Lactate dehydrogenase activity (P < .001) and interleukin-6 mRNA levels were significantly higher in the non-IP group than in the sham and IP groups (P = .002, both groups).

CONCLUSIONS

Our results demonstrate that IP under propofol anesthesia significantly attenuated hepatic IRI. The principal mechanism of the protective effects appeared to involve reduced expression of the IL-6 pro-inflammatory cytokine and subsequent reduction of the degree of necrosis.

Systemic Oxygen Delivery during One-Lung Ventilation: Comparison between Propofol and Sevoflurane Anaesthesia in a Randomised Controlled Trial

Systemic oxygen delivery (DO₂) is a more comprehensive marker of patient status than arterial oxygen saturation (SaO₂), and DO₂ in the range of 330–500 mL min⁻¹ is reportedly adequate during anaesthesia. We measured DO₂ during one-lung ventilation (OLV) for thoracic surgery—where the risk of pulmonary shunt is significant, and hypoxia occurs frequently—and compared sevoflurane and propofol, the two most commonly used anaesthetics in terms of DO₂. Sevoflurane impairs hypoxic pulmonary vasoconstriction. Thus, our hypothesis was that propofol-based anaesthesia would show a higher DO₂ value than sevoflurane-based anaesthesia. This was a double-blinded randomised controlled trial conducted at a university hospital from 2017 to 2018. The study population consisted of patients scheduled for lobectomy under OLV (N = 120). Sevoflurane or propofol was titrated to a bispectral index of 40–50. Haemodynamic variables were measured during two-lung ventilation (TLV) and OLV at 15 and 45 min (OLV15 and OLV45, respectively) using oesophageal Doppler monitoring. The mean DO₂ (mL min⁻¹) was not different between the sevoflurane and propofol anaesthesia groups (TLV: 680 vs. 706; OLV15: 685 vs. 703; OLV45: 759 vs. 782, respectively). SaO₂ was not correlated with DO₂ (r = 0.09, p = 0.100). Patients with SaO₂ < 94% showed adequate DO₂ (641 ± 203 mL min⁻¹), and patients with high SaO₂ (> 97%) showed inadequate DO₂ (14% of measurements < 500 mL min⁻¹). In conclusion, DO₂ did not significantly differ between sevoflurane and propofol. SaO₂ was not correlated with DO₂ and was not informative regarding whether the patients were receiving an adequate oxygen supply. DO₂ may provide additional information on patient status, which may be especially important when patients show a low SaO₂.

Postoperative pain control after the use of dexmedetomidine and propofol to sedate patients undergoing ankle surgery under spinal anesthesia: a randomized controlled trial

Background: Dexmedetomidine is widely used for conscious sedation in patients undergoing lower-extremity surgery under regional anesthesia. We evaluated the postoperative analgesic effects of intravenous dexmedetomidine given during ankle surgery under spinal anesthesia.

Methods: Forty-three participants underwent repair of lateral angle ligaments under spinal anesthesia. For sedation during surgery, participants were allocated to a dexmedetomidine group (n=22) that received a loading dose of 1 mcg.kg⁻¹ over 10 min, followed by a maintenance dose of 0.2–0.7 μg.kg⁻¹.h⁻¹; and a propofol group (n=21) that received an effective site concentration of 0.5–2.0 μg.mL⁻¹ via target-controlled infusion. The primary outcome was the postoperative, cumulative, intravenous (IV) morphine equivalent dose delivered via IV patient-controlled anesthesia (PCA) and rescue analgesic consumption in the first 24 h after surgery. We recorded sensory and motor block durations.

Results: The postoperative IV morphine equivalent dose was 14.5 mg (0.75–31.75 mg) in the dexmedetomidine group compared to 48.0 mg (31.5–92.5 mg) in the propofol group (median difference, 33.2 mg; 95% confidence interval, 21.0–54.8 mg; P<0.001). The time to the first complaint of surgical site pain was significantly prolonged in the dexmedetomidine group (P<0.001), but the duration of motor block was comparable between the two groups (P=0.55).

Conclusion: IV dexmedetomidine given as a sedative during ankle surgery under spinal anesthesia reduced postoperative opioid consumption in the first 24 h. Thus, intraoperative dexmedetomidine is a versatile sedative adjunct.

Level of evidence: Level I, prospective randomized trial.

Incidence and risk factors of unplanned intubation during pediatric sedation for MRI

BACKGROUND

It is often difficult for the pediatric patient to cooperate or to remain immobile during MR scans. Therefore, sedation is usually needed for children.

PURPOSE

To evaluate the incidence and contributing factors of unanticipated intubation during sedation for MRI scan in children.

STUDY TYPE

Retrospective observational study.

POPULATION/SUBJECTS

In all, 1165 charts were reviewed retrospectively of patients who had been sedated by anesthesiologists at a single institution from May 2015 to June 2016.

ASSESSMENT

Patient's demographics, the region of the MRI scan, total amount of medication, duration of sedation, and any adverse event during MRI were assessed. The adverse events during sedation including airway obstruction, apnea, desaturation, bradycardia, and hypotension were also assessed.

STATISTICAL TESTS

Risk factors of unplanned intubation during MRI sedation were identified by univariate and multivariate analysis. Firth's exact logistic regression was used for univariate and multivariate analysis. According to the results from multiple logistic regression, a nomogram was developed to predict the risk.

RESULTS

A total of 1165 children aged 7 days to 18 years with sedation used during an MRI scan during the study period showed an incidence of unexpected intubation as ~2% (n = 23, 95% confidence interval [CI]; 0.0123, 0.0295). Multivariate logistic regression revealed the following risk factors of unplanned intubation: American Society of Anesthesiologists (ASA) class III patients (odds ratio [OR] 1.212, P < 0.001), premature birth (OR 2.317, P < 0.001), and the presence of gastroesophageal reflux disease (GERD) (OR 1.474, P < 0.001) or congenital heart disease (OR 1.118, P < 0.001).

DATA CONCLUSION

This study identified risk factors of unplanned intubation as follows: ASA class III patients, premature birth, and the presence of GERD or congenital heart disease. The physician should screen risk factors of unexpected intubation and maintain adequate sedation during MRI scans in pediatric patients. Level of Evidence 3. Technical Efficacy Stage 5. J. Magn. Reson. Imaging 2019;49:1053-1061.

A retrospective comparison of propofol to dexmedetomidine for pediatric magnetic resonance imaging sedation in patients with mucopolysaccharidosis type II

BACKGROUND

Mucopolysaccharidosis type II patients are reported to have an elevated incidence of difficult airway. Propofol is a commonly used sedative for magnetic resonance imaging in pediatric patients, but patients who receive it may exhibit dose-dependent upper airway obstruction and respiratory depression. Dexmedetomidine also provides adequate procedural sedation with a relatively low risk of airway obstruction. Accordingly, we introduced the use of dexmedetomidine in our practice to reduce the risk of airway obstruction during magnetic resonance imaging procedures.

AIMS

The aim of this study was to evaluate the incidence of artificial airway interventions in patients sedated with propofol and compare it to that in patients sedated with dexmedetomidine in patients with mucopolysaccharidosis type II during magnetic resonance imaging procedures.

METHODS

All mucopolysaccharidosis type II patients undergoing magnetic resonance imaging at our institution between April 2014 and February 2018 were included in this study. The patients were divided into two groups according to whether they were managed before and after the introduction of dexmedetomidine: those who were sedated with propofol (group P) and those who were sedated with dexmedetomidine (group D).

RESULTS

Forty-six sedations were performed in 27 patients. Artificial airway interventions were significantly more frequent during propofol-based than dexmedetomidine-based sedation: 14 of 32 (43.8%) in group P and 1 of 14 (7.1%) in group D (odds ratio, 10.11; 95% confidence interval, 1.18-86.85; P = 0.018). Time to awake and time to discharge were similar between groups. Changes in hemodynamic variables also did not significantly differ between groups.

CONCLUSION

Dexmedetomidine provides an adequate level of sedation and is associated with lower rates of artificial airway interventions compared to propofol. Therefore, dexmedetomidine may offer advantages for preserving the native airway compared to propofol when administered during magnetic resonance imaging scans in patients with mucopolysaccharidosis type II.

Increased expression of the Cbl family of E3 ubiquitin ligases decreases Interleukin-2 production in a rat model of peripheral neuropathy

Background

Interleukin 2 (IL-2) influences the development and severity of pain due to its antinociceptive and immunomodulatory effects. Its production is influenced by the increased expression of c-Cbl (Casitas B-lineage lymphoma proto-oncogene) and Cbl-b E3 ubiquitin ligases. We evaluated the effects on IL-2-mediated changes in c-Cbl and Cbl-b expression in a rat model of chronic neuropathic pain.

Methods

Peripheral neuropathy was induced in adult male Sprague-Dawley rats weighing 250–300 g by chronic spinal nerve ligation. Half of the spinal cord ipsilateral to the nerve injury was harvested at 1, 3, and 6 weeks, and the expression levels of IL-2, c-Cbl, Cbl-b, phospholipase C-γ1 (PLC-γ1), ZAP70, and protein kinase Cθ (PKCθ), as well as ubiquitin conjugation, were evaluated.

Results

Total IL-2 mRNA levels were significantly decreased at 3 and 6 weeks after nerve injury compared to those in sham-operated rats. The mRNA levels of c-Cbl and Cbl-b, as well as the level of ubiquitin conjugation, were significantly increased at 3 and 6 weeks. In contrast, the levels of phosphorylated ZAP70 and PLC-γ1 were decreased at 3 and 6 weeks after spinal nerve ligation. Ubiquitination of PLC-γ1 and PKCθ was increased at 3 and 6 weeks.

Conclusions

Our results suggest that ubiquitin and the E3 ubiquitin ligases c-Cbl and Cbl-b function as neuroimmune modulators in the subacute phase of neuropathic pain after nerve injury.

A case series on simultaneous liver and kidney transplantation: do we need intraoperative renal replacement therapy?

Since the implementation of the model for end-stage liver disease (MELD) scoring system in 2002, the liver transplantation (LT) society has observed a substantial increase in the number of recipients with renal dysfunction. Intraoperative renal replacement therapy (ioRRT) has emerged as one of the solutions available to manage high-MELD score recipients; however, its usefulness has not yet been proven. To date, we have experienced five cases of simultaneous liver and kidney transplantation (SLKT). Recipients of SLKT tend to have a lower pre-transplant kidney function and the longer operation time mandates a larger amount of fluid than LT alone. Hence, anesthetic care is more prone to be challenged by hyperkalemia, metabolic acidosis, and volume overload, making ioRRT a theoretically valuable intervention. However, in all five cases, recipients were managed without ioRRT, resulting in excellent graft and patient survival. As such, in this case series, we discuss current issues about ioRRT and SLKT.

Obesity is independently associated with spinal anesthesia outcomes: a prospective observational study

The influence of body-mass index (BMI) on spinal anesthesia is still controversial, with discrepant results reported in previous studies. To compare spinal anesthesia in obese and non-obese subjects, the anesthesia profiles in patients who underwent spinal anesthesia using intrathecal hyperbaric bupivacaine were compared. A total of 209 patients undergoing elective total knee replacement arthroplasty (TKRA) surgery under spinal anesthesia were divided into an NO (non-obese) group (BMI < 30 kg/m², n = 141) and an O (obese) group (BMI ≥ 30 kg/m², n = 68). Anesthesia was deemed successful if a bilateral T12 sensory block occurred within 15 minutes of intrathecal drug administration, and if the level of sensory block was higher than T12 when the surgery ended. Logistic regression analysis with multiple variables known to influence spinal anesthesia was performed to identify which parameters independently determined the spinal anesthesia outcome. Similar doses of bupivacaine were administered to the NO and O groups. The incidence of anesthesia failure was significantly lower in the O group [n = 43 (30.5%) in the NO group vs. n = 10 (18.9%) in the O group, p = 0.014]. The independent predictors for successful anesthesia in all patients were dose of hyperbaric bupivacaine [odds ratio (OR) 2.12, 95% CI: 1.64–2.73] and obese status (BMI ≥ 30 kg/m², OR 2.86, 95% CI: 1.25–6.52). Time to first report of postoperative pain and time to first self-void were significantly longer in the O group. These results suggest that the duration of block with hyperbaric bupivacaine is prolonged in obese patients and obesity is independently associated with spinal anesthesia outcomes, as is bupivacaine dosage. A further study enrolling patients with morbid obesity and using a fixed bupivacaine dosage is required to confirm the effect of obesity on spinal anesthesia.

Cosmetic outcomes of laparoendoscopic single-site hysterectomy compared with multi-port surgery: randomized controlled trial

STUDY OBJECTIVE

To compare cosmetic satisfaction with laparoendoscopic single-site surgery (LESS) compared with multi-port surgery.

DESIGN

Randomized controlled trial (Canadian Task Force classification I).

SETTING

University hospital.

PATIENTS

Twenty women who underwent laparoscopically-assisted vaginal hysterectomy (LAVH) via LESS or multi-port surgery.

INTERVENTIONS

Laparoendoscopic single-site surgery or multi-port surgery.

MEASUREMENT AND MAIN RESULTS

Cosmetic satisfaction was assessed using the Body Image Questionnaire at baseline and at 1, 4, and 24 weeks after surgery. Of the 20 LESS procedures, 1 was converted to multi-port surgery because of severe adhesions, and 1 woman assigned to undergo multi-port surgery was lost to follow-up. The 2 surgery groups did not differ in clinical demographic data and surgical results or postoperative pain scores at 12, 24, and 36 hours. Compared with the multi-port group, the LESS group reported significantly higher cosmetic satisfaction at 1, 4, and 24 weeks after surgery (p < .01).

CONCLUSION

Compared with multi-port surgery, LESS is not only a feasible approach with comparable operative outcomes but also has an advantage insofar as cosmetic outcome.

Combined carbamazepine and pregabalin therapy in a rat model of neuropathic pain

BACKGROUND

Carbamazepine and pregabalin have proven effects against neuropathic pain. Carbamazepine blocks voltage-dependent Na(+) channels, whereas pregabalin blocks voltage-dependent Ca(2+) channels. The authors hypothesized that the co-administration of these drugs would synergistically reduce neuropathic pain.

METHODS

Neuropathic pain was induced by L5 nerve ligation in Sprague-Dawley rats. To determine their ED(50) values, carbamazepine and pregabalin were orally administered at 0.3, 3, 10, or 30 mg kg(-1). The drugs were then co-administered at 0, 1/4×ED(50), 1/2×ED(50), 1.5×ED(50), and 2×ED(50) to determine the ED(50) and ED(75) values of the drugs in combination. Allodynia was determined using the von Frey hair test and dose-effect curves and isobolograms were used to investigate drug interactions. Levels of the acute reactive protein c-Fos in the dorsal horn were evaluated as an indicator of pathological nerve excitation.

RESULTS

At ED(50) levels, carbamazepine and pregabalin did not exhibit synergism, but doses higher than ED(75) were found to be synergistic. The combination index was 0.18 (strong synergy) and dose reductions were 35.7-fold for carbamazepine and 6.8-fold for pregabalin when co-administered when compared with a single administration at ED(75). The percentage allodynia relief was only 60% for carbamazepine and 80% for pregabalin by single administration, whereas their co-administration relieved allodynia by 100%. Furthermore, treatment decreased c-Fos expression in the dorsal horn, but expressional differences between animals treated with carbamazepine plus pregabalin were not significantly different from those treated with single drug.

CONCLUSIONS

Carbamazepine and pregabalin ameliorate neuropathic pain synergistically at higher doses.

Edge temperature gradient as intrinsic rotation drive in Alcator C-Mod tokamak plasmas

Intrinsic rotation has been observed in I-mode plasmas from the C-Mod tokamak, and is found to be similar to that in H mode, both in its edge origin and in the scaling with global pressure. Since both plasmas have similar edge ∇T, but completely different edge ∇n, it may be concluded that the drive of the intrinsic rotation is the edge ∇T rather than ∇P. Evidence suggests that the connection between gradients and rotation is the residual stress, and a scaling for the rotation from conversion of free energy to macroscopic flow is calculated.

Trapped electron mode turbulence driven intrinsic rotation in Tokamak plasmas

Progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal plasmas is reported. The turbulence-driven intrinsic torque associated with nonlinear residual stress generation due to zonal flow shear induced asymmetry in the parallel wave number spectrum is shown to scale close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing experimental empirical scalings of intrinsic rotation. The origin of current scaling is found to be enhanced k(∥) symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The intrinsic torque is proportional to the pressure gradient because both turbulence intensity and zonal flow shear, which are two key ingredients for driving residual stress, increase with turbulence drive, which is R/L(T(e)) and R/L(n(e)) for the trapped electron mode.

[Effects of Nei-Guan acupressure on nausea, vomiting and level of satisfaction for gynecological surgery patients who are using a patient-controlled analgesia]

PURPOSE

This study was done to examine effects of Nei-Guan acupressure on nausea, vomiting and level of satisfaction for gynecological surgery patients who were using a patient-controlled analgesia (PCA).

METHODS

For this study, 51 patients were assigned to one of three groups, a control group (17 patients), experimental group 1 (finger acupressure group) (17 patients), and experimental group 2 (relief band group) (17 patients). The data were collected for 24 hr in the recovery room of a university hospital located in Seoul. The 6 hr-intervals including the time of leaving the recovery room were taken into consideration.

RESULTS

The occurrence of nausea between the experimental group with Nei-Guan acupressure treatment and the control group was different. However, there was no difference in nausea and vomiting control or level of patient satisfaction between the finger acupressure group and the relief band group.

CONCLUSION

Nei-Guan acupressure is recommended for nursing practice as a way for alleviating the opioid-induced nausea and accelerating the recovery of patients who are using PCA after surgery.

Cardiovascular effects and predictability of cardiovascular collapse after repeated intravenous bolus injections of absolute ethanol in anesthetized pigs

PURPOSE

To evaluate the effects of repeated intravenous bolus injections of absolute ethanol on cardiopulmonary hemodynamic changes and to investigate the predictability of ethanol-induced cardiovascular collapse in anesthetized pigs.

MATERIALS AND METHODS

Twenty pigs aged 3-6 months and weighing 28-38 kg were enrolled in the study. Absolute ethanol (0.1 mL/kg of body weight) was repeatedly injected through the inferior vena cava central to the renal vein at 10-minute intervals up to a total volume of 1.0 mL/kg. The subjects were divided into a cardiovascular collapse group and a no-collapse group according to the development or absence of cardiac collapse.

RESULTS

Among the 20 pigs, 12 died before the final injection. Hemodynamic parameters measured immediately before the injection of absolute ethanol did not differ between the cardiovascular collapse group and the no-collapse group except that among animals with cardiovascular collapse, the injection immediately before the one causing cardiovascular collapse resulted in significant increases in the following hemodynamic parameters: mean pulmonary arterial pressure (P < .01), pulmonary vascular resistance (P = .04), and right ventricular end-diastolic volume (P = .02). No such increases were observed in the no-collapse group.

CONCLUSIONS

Hemodynamic profiles in pigs obtained immediately before intravenous injection of absolute ethanol did not predict the subsequent occurrence of cardiovascular collapse except after the injection immediately preceding the one resulting in cardiovascular collapse. In this animal model, significant increases in select hemodynamic parameters occurred after the injection immediately preceding the one resulting in cardiovascular collapse.

Unilateral massive hydrothorax in a gynecologic patient with pseudo-Meigs' syndrome -A case report-

Pseudo-Meigs' syndrome is characterized by the presence of a benign ovarian tumor associated with ascites and a right-sided hydrothorax. The major problem associated with pseudo-Meigs' syndrome is the respiratory distress caused by a giant mass in the peritoneal space, massive ascites and pleural effusion. Even if there are no respiratory problems prior to surgery, potential respiratory dysfunction can occur during the peri-anesthetic period, leading to hypoxia, hypercapnea and respiratory acidosis. We report a case of hypoxia during recovery from anesthesia in a gynecological patient with pseudo-Meigs' syndrome.

Comparison of the prophylactic anti-emetic efficacy of ramosetron and ondansetron in patients at high-risk for postoperative nausea and vomiting after total knee replacement

We compared the prophylactic anti-emetic efficacy of ramosetron, a newly developed 5-HT(3) antagonist, and ondansetron in patients at high-risk for postoperative nausea and vomiting after total knee replacement. Eighty-four patients with three risk factors for postoperative nausea and vomiting (female, non-smoking and use of postoperative opioid use (ropivacaine and hydromorphone patient controlled epidural analgesia)) undergoing unilateral total knee replacement were randomly allocated to ramosetron 0.3 mg (n = 42) or ondansetron 4 mg (n = 42) groups. A complete response (no postoperative nausea and vomiting and no rescue anti-emetic) and the incidence of postoperative nausea and vomiting were assessed for 48 h after surgery at 0-2 h, 2-6 h, 6-24 h, and 24-48 h. More patients in the ramosetron group had a complete response between 2 and 48 h. The incidence of nausea between 2 and 24 h and the severity of nausea between 2 and 48 h were also less in the ramosetron group. Ramosetron was more effective than ondansetron in preventing postoperative nausea and vomiting in patients at high risk undergoing unilateral total knee replacement.

Recovery of nicotine-free proteins from tobacco leaves using phosphate buffer system under controlled conditions

Establishment of an effective, high-throughput processing system to recover protein from tobacco with no nicotine contamination is essential and vital to the development of value-added, alternative applications for tobacco farmers. We have successfully developed a mechanism capable of processing up to 60 kg of tobacco leaves per hour with phosphate buffer (Na(2)HPO(4)-KH(2)PO(4)) simultaneously added to stabilize the protein as the plant was being disintegrated. The optimal processing parameters were identified, including the ratio of buffer to leaf (BLR) at 4.75 (w/w), buffer pH 7.85, and buffer concentration 0.085 mol/L, achieving a maximum yield of soluble protein at 12.85 mg/g fresh leaf. Acetone at -20 degrees C was the most effective among all methods investigated to remove nicotine from protein; however, it also drastically reduced the recovery rate of protein (63.3%). Ultrafiltration was only able to remove about 50% of the residual nicotine, although the protein recovery rate was high (94.7%). The residual nicotine content inherent in the recovered protein was completely removed by rinsing the protein with 85% phosphoric acid at pH 3.5 for three times with a protein recovery of 94.5%. The pilot-scale operation provides a solid foundation for further scale-up to industrial production of nicotine-free tobacco protein that could bring added value to tobacco for nonsmoking applications.

Toroidal rotation driven by the polarization drift

Starting from a phase space conserving gyrokinetic formulation, a systematic derivation of parallel momentum conservation uncovers a novel mechanism by which microturbulence may drive intrinsic rotation. This mechanism, which appears in the gyrokinetic formulation through the parallel nonlinearity, emerges due to charge separation induced by the polarization drift. The derivation and physical discussion of this mechanism will be pursued throughout this Letter.

Intrathecal morphine combined with intravenous patient-controlled analgesia is an effective and safe method for immediate postoperative pain control in live liver donors

The healthy condition of living donors makes their tolerance to pain particularly low, and clinicians are often challenged to come up with an analgesic technique that is effective yet ensures donor safety. This study compared, in donor right hepatectomy, the efficacy and safety of preoperative intrathecal morphine (ITM) combined with intravenous patient-controlled analgesia (IV-PCA) with IV-PCA alone. Forty adult patients were randomly allocated into 2 groups: ITM+IV-PCA group (n = 20) and IV-PCA-only group (n = 20). Patients in the ITM+IV-PCA group received morphine sulfate (400 microg). The visual analog scale (VAS) at rest and when coughing and supplementary meperidine and IV-PCA (fentanyl) consumption were assessed at 2, 4, 6, 8, 10, 12, 18, 24, 30, 36, 42, 48 56, 64, and 72 hours after surgery. Also, side effects such as sedation, dizziness, nausea, vomiting, pruritus, and respiratory depression were evaluated. The ITM+IV-PCA group showed significantly less pain at rest and when coughing for up to 30 hours and 24 hours, respectively. Cumulative postoperative consumption of meperidine and IV-PCA (fentanyl) were significantly less in the ITM+IV-PCA group. The incidence of side effects were comparable between the 2 groups except for pruritus; its incidence was significantly higher in the ITM+IV-PCA group during the first 24 hours, but no treatment was required due to its mild severity. The results of our study suggest that preoperative ITM combined with IV-PCA may be considered as an effective and safe pain management regimen in living liver donors who have characteristics of low tolerance to pain and postoperative coagulation derangement.

Protective effects of gabapentin on allodynia and alpha 2 delta 1-subunit of voltage-dependent calcium channel in spinal nerve-ligated rats

This study was designed to determine whether early gabapentin treatment has a protective analgesic effect on neuropathic pain and compared its effect to the late treatment in a rat neuropathic model, and as the potential mechanism of protective action, the alpha(2)delta(1)-subunit of the voltage-dependent calcium channel (alpha(2)delta(1)-subunit) was evaluated in both sides of the L5 dorsal root ganglia (DRG). Neuropathic pain was induced in male Sprague-Dawley rats by a surgical ligation of left L5 nerve. For the early treatment group, rats were injected with gabapentin (100 mg/kg) intraperitoneally 15 min prior to surgery and then every 24 hr during postoperative day (POD) 1-4. For the late treatment group, the same dose of gabapentin was injected every 24 hr during POD 8-12. For the control group, L5 nerve was ligated but no gabapentin was administered. In the early treatment group, the development of allodynia was delayed up to POD 10, whereas allodynia was developed on POD 2 in the control and the late treatment group (p<0.05). The alpha(2)delta(1)-subunit was up-regulated in all groups, however, there was no difference in the level of the alpha(2)delta(1)-subunit among the three groups. These results suggest that early treatment with gabapentin offers some protection against neuropathic pain but it is unlikely that this action is mediated through modulation of the alpha(2)delta(1)-subunit in DRG.

Gyrokinetic studies on turbulence-driven and neoclassical nondiffusive toroidal-momentum transport and the effect of residual fluctuations in strong E x B shear

A significant inward flux of toroidal momentum is found in global gyrokinetic simulations of ion temperature gradient turbulence, leading to core plasma rotation spin-up. The underlying mechanism is identified to be the generation of residual stress due to the k parallel symmetry breaking induced by global quasistationary zonal flow shear. Simulations also show a significant off-diagonal element associated with the ion temperature gradient in the neoclassical momentum flux, while the overall neoclassical flux is small. In addition, the residual turbulence found in the presence of strong E x B flow shear may account for neoclassical-level ion heat and anomalous momentum transport widely observed in experiments.

Endotracheal intubation in a patient with an almost complete obstruction of the glottis due to a movable supraglottic tumor: A case report

Intubation in patients with an obstruction of the glottis due to a large mass may present great challenge to most anesthesiologists. If tracheostomy is not available, flexible fiberscope guided endotracheal intubation is now the part of the standard management in these cases, but difficulty in advancing the tracheal tube over the fiberscope and into the trachea may be encountered. In this case, a 60-year-old male with a huge supraglottic mass was given general anesthesia for laryngomicroscopic surgery and debulking of the mass lesion. We planned an awake flexible fiberoptic intubation but failed to railroad the tube over the fiberscope even after successfully placing the scope inside the trachea. During various attempts to pass the tracheal entrance, the patient coughed and the tube slid into the trachea as mass moved aside and we could successfully secure the airway.

Turbulent equipartition and homogenization of plasma angular momentum

A physical model of turbulent equipartition (TEP) of plasma angular momentum is developed. We show that using a simple, model insensitive ansatz of conservation of total angular momentum, a TEP pinch of angular momentum can be obtained. We note that this term corresponds to a part of the pinch velocity previously calculated using quasilinear gyrokinetic theory. We observe that the nondiffusive TEP flux is inward, and therefore may explain the peakedness of the rotation profiles observed in certain experiments. Similar expressions for linear toroidal momentum and flow are computed and it is noted that there is an additional effect due the radial profile of moment of inertia density.

Wave-particle decorrelation and transport of anisotropic turbulence in collisionless plasmas

Comprehensive analysis of the largest first-principles simulations to date shows that stochastic wave-particle decorrelation is the dominant mechanism responsible for electron heat transport driven by electron temperature gradient turbulence with extended radial streamers. The transport is proportional to the local fluctuation intensity, and phase-space island overlap leads to a diffusive process with a time scale comparable to the wave-particle decorrelation time, determined by the fluctuation spectral width. This kinetic time scale is much shorter than the fluid time scale of eddy mixing.

Comparison of surgical conditions during propofol or sevoflurane anaesthesia for endoscopic sinus surgery

BACKGROUND

Endoscopic sinus surgery (ESS) is often affected by intra-nasal bleeding, which can be influenced by various anaesthetics and preoperative conditions. This study compared the surgical condition and the amount of intra-nasal bleeding between patients given sevoflurane/remifentanil (SR) and propofol/remifentanil (PR) anaesthesia.

METHODS

ASA I or II patients undergoing ESS were randomly assigned to group SR (n=20) or group PR (n=20). The extent of the preoperative surgical lesion was classified as high (> 12) and low Lund-Mackay (LM) (< or = 12) scores according to the computed tomography findings. The amount of intraoperative blood loss was calculated from the patients' haemoglobin (Hb) and the amount of blood in the suction canister. The surgeons rated the visibility of the surgical field on a numeric rating scale (NRS).

RESULTS

In the high-LM score patients, the median (1st/3rd quartiles) blood loss for the SR and PR groups was 135 (121/222) and 19 (8/71) ml h(-1), respectively (P<0.01), and the mean (SD) of NRS was 5.8 (2.3) and 2.3 (1.0), respectively (P<0.05). However, in patients with low-LM score, both blood loss and NRS scores were not different between groups SR and PR.

CONCLUSIONS

In the high-LM score patients, PR anaesthesia results in less blood loss and a better surgical conditions for ESS than SR anaesthesia.

Comparison of femoral arterial blood pressure with radial arterial blood pressure and noninvasive upper arm blood pressure in the reperfusion period during liver transplantation

PURPOSE

The reperfusion period during liver transplantation is hemodynamically unstable. Accurate blood pressure measurements are the mainstay for the efficient management of abrupt cardiovascular changes. We sought to compare femoral arterial blood pressure (FABP) with radial arterial blood pressure (RABP) and noninvasive upper arm blood pressure (NIBP) in the reperfusion period.

METHODS

Thirty-six adult living donor liver recipients were enrolled in this prospective study. Blood pressures in 3 locations were simultaneously recorded from 1 minute before reperfusion to 15 minutes after reperfusion. We evaluated agreements between FABP and RABP and between FABP and NIBP using intraclass correlation coefficients. Also, we investigated the rates of postreperfusion syndrome (PRS) based on the measurements from 3 locations.

RESULTS

After reperfusion, the mean and diastolic RABP agreed more with the corresponding FABP than NIBP. However, systolic NIBP showed high agreement with FABP from 3 to 10 minutes after reperfusion in contrast with the moderate agreement between systolic RABP with FABP, and systolic values of NIBP than RABP were closer to FABP. The rates of PRS based on FABP, RABP, and NIBP measurements were 50.0% (18/36), 80.6% (29/36), and 50.0% (18/36), respectively.

CONCLUSIONS

We believe that NIBP in addition to RABP may be considered to be a reliable alternative when FABP is not available to evaluate hemodynamic instability in the reperfusion period during liver transplantation.

The effect of 2 Hz and 100 Hz electrical stimulation of acupoint on ankle sprain in rats

The electrical stimulation of acupoint (ESA) releases several endogenous neuropeptides, which play important roles in management of pain and inflammation. ESA with low and high frequencies has been shown to release different neuropepides, suggesting its various therapeutic effects. Pain and edema are major problems for ankle sprain. However, there have been few reports on the effects of ESA for ankle sprain. We aimed to investigate that ESA can reduce pain and edema resulting from ankle sprain, and whether there is a difference in therapeutic effects between low and high frequency ESA. To induce ankle sprain in Sprague-Dawley rats, the ankle of right hindpaw was overextended in direction of simultaneous inversion and plantar flexion. Stepping force and edema in the paw of the sprained ankle were measured by electronic balance and plethysmometer, respectively. In both 2 and 100 Hz ESA groups, stepping force was increased significantly in similar degrees (p<0.05). Only 2 Hz ESA produced the significant rapid decrease in ankle edema. This study demonstrates that ESA of 2 Hz and 100 Hz shows comparable analgesic effects, but only 2 Hz ESA can facilitate the reduction of edema caused by ankle sprain.

The changes in coagulation profile and epidural catheter safety for living liver donors: a report on 6 years of our experience

The use of epidural catheters has been a subject of active debate in living liver donors because of the possible postoperative coagulation derangement and the subsequent risk of epidural hematoma. The aim of this study was to evaluate the safety of epidural catheters in relation to the changes in coagulation profile based on a review of previously published literature and the results of our 360 donors. In both the literature and in our cases, platelet count, prothrombin time (PT), and activated partial thromboplastin time (aPTT) in cases of heparin administration showed significant changes (P < 0.05), especially after right lobectomy. Platelet count reached its nadir on postoperative day (POD) 2-3, while PT and aPTT reached their peaks on POD 1-2 and at the end of the operation, respectively. In our donors, the ranges of platelet count, PT, and aPTT for the first 3 PODs were 54-359 x10/microL, 0.99-2.38 international normalized ratio (INR), and 25.9-300 seconds, respectively, and of note, 5 donors (1.4%) had a platelet count of <80 x 10/microL and 9 donors (2.5%) had a PT of >2.0 INR. Epidural catheterizations were performed in 242 donors, and the catheters were removed on POD 3-4 in 177 donors (73.1%). Mean (range) of platelet count, PT, and aPTT on the day of catheter removal were 168.4 +/- 42.9 (82-307) x 10/microL, 1.33 +/- 0.18 (0.99-1.93) INR, and 40.9 +/- 4.8 (32.0-70.6) seconds, respectively. No epidural hematoma was observed in this study. In conclusion, the discreet use of epidural catheters in live liver donors, in spite of postoperative coagulation derangements, appears to be safe regardless of the type of hepatectomy performed.

A correlation between low back pain and associated factors: a study involving 772 patients who had undergone general physical examination

Many factors are associated with the development of low back pain. Among them, exercise, obesity, smoking, age, educational level and stress are the most common. This study examined the association of these factors with low back pain. An additional aim was to determine a procedure for preventing low back pain. This study analyzed the responses to a questionnaire sent to 772 individuals who had undergone a medical examination at this hospital in 2003 and excluded the individuals who had shown symptoms or their test results indicated a particular disease. Assuming that there were no variables, individuals who exercised regularly 3-4 times per week would have a lower chance of having low back pain than those who did not exercise regularly. The analysis revealed that individuals with a college degree or higher education have a lower chance of experiencing low back pain than those with only a high school education or even college drop-outs. When the other variables were constant, age, extent of obesity (body mass index), smoking and level of stress were not found to affect the development of low back pain. The level of education was associated with the development of low back pain. However, regular exercise 3-4 times per week or more would be most effective in reducing the incidence and duration of low back pain.

The Hemostatic Profiles of Patients with Type O and Non-O Blood After Acute Normovolemic Hemodilution with 6% Hydroxyethyl Starch (130/0.4)

BACKGROUND

Individuals with Type O blood have been reported to have a tendency toward reduced Factor VIII and von Willebrand Factor (vWF) levels. If this is true, patients with Type O blood might be vulnerable to coagulopathy during acute normovolemic hemodilution using hydroxyethyl starch (HES), both from hemodilution as well as HES-related coagulopathy.

METHODS

Thirty non-O and 15 type O ASA 1 or 2 patients scheduled for spinal surgery involving more than two spinal levels were enrolled for the study. After anesthesia induction, 30% of the estimated blood volume was removed, and the volume was simultaneously replaced with 6% HES (130/0.4). Coagulation profiles were measured before (T0) and 30 min after acute normovolemic hemodilution (T30).

RESULTS

Factor VIII activity, vWF antigen levels (vWF:ag), and vWF ristocetin cofactor activity (vWF:RCof) were lower in the O group than in the non-O group before and after acute normovolemic hemodilution, and decreased below the normal range in the O group after acute normovolemic hemodilution. The decrease was beyond that expected from hemodilution alone. Maximum amplitude and coagulation index of the thromboelastogram decreased below the normal range in the O group after acute normovolemic hemodilution. The decrease in vWF:ag was related to the degree of blood loss, and was greater in patients in the O group.

CONCLUSIONS

Patients with Type O blood may have increased coagulation compromise, and greater dilution of Factor VIII activity, vWF:ag, and vWF:RCof after acute normovolemic hemodilution with HES.

Nonlinear triad interactions and the mechanism of spreading in drift-wave turbulence

We present the results of a derivation of the fluctuation energy transport matrix for the two-field Hasegawa-Wakatani model of drift wave turbulence. The energy transport matrix is derived from a two-scale direct interaction approximation assuming weak turbulence. We examine different classes of triad interactions and show that radially extended eddies, as occurs in penetrative convection, are the most effective in turbulence spreading. We show that in the near-adiabatic limit internal energy spreads faster than the kinetic energy. Previous theories of spreading results are discussed in the context of weak turbulence theory.