A comparison of the continuous supraclavicular brachial plexus block using the proximal longitudinal oblique approach and the interscalene brachial plexus block for arthroscopic shoulder surgery: A randomised, controlled, double-blind trial

BACKGROUND

Continuous interscalene brachial plexus block (ISB) is widely used for arthroscopic shoulder surgery, but the incidence of hemidiaphragmatic paresis (HDP) has been reported to reach 100%. Several methods, including injections distal to the C5-C6 nerve roots, have been attempted to reduce the HDP incidence. However, catheter placement distal to the C5-C6 nerve roots interferes with the surgical site.

OBJECTIVE

Our primary objective was to describe a new technique, the supraclavicular brachial plexus block (SCB), using the proximal longitudinal oblique approach (PLO-SCB), which can facilitate catheter placement and, when compared with ISB, to test whether this would provide noninferior analgesia and spare the phrenic nerve.

DESIGN

Prospective, randomised, double-blind study.

SETTING

Operating rooms, postanaesthesia care unit, and wards.

PATIENTS

Seventy-six patients aged 20 to 80 years scheduled for arthroscopic shoulder surgery.

INTERVENTIONS

Patients were randomly assigned to the continuous PLO-SCB ( n  = 40) or the continuous ISB ( n  = 40) groups. All patients received an initial low-volume single-injection (5 ml 0.75% ropivacaine) followed by a patient-controlled infusion of 0.15% ropivacaine.

MAIN OUTCOME MEASURES

The primary outcomes were the incidence of HDP and pain scores. Secondary outcomes were respiratory function, postoperative analgesic consumption, sensory and motor function, and complications.

RESULTS

The HDP incidence was significantly lower in the PLO-SCB group than in the ISB group at 30 min after block injection: 0% (0 of 38 patients) and 73.7% (28 of 38 patients), respectively ( P  < 0.001). Similarly, at 24 h after surgery, the incidences were 23.7% (9 of 38 patients) and 47.4% (18 of 38 patients) in the PLO-SCB and ISB groups, respectively ( P  = 0.002). Median [IQR] NRS pain scores at rest measured after surgery in the ISB and PLO-SCB groups were similar: immediately after surgery, 1 [0 to 2] vs. 1 [0 to 1], P  = 0.06); at 30 min, 2 [0.25 to 2] vs. 1 [0 to 2], P  = 0.065); and at 24 h 2 [0.25 to 3] vs. 1 [0 to 3], P  = 0.47, respectively.

CONCLUSION

For major shoulder surgery, compared with continuous ISB, continuous PLO-SCB was more sparing of diaphragmatic and respiratory function while providing noninferior analgesia. Catheter placement via the PLO approach is feasible without interfering with the surgical field.

TRIAL REGISTRATION

Registered by the Clinical Trial Registry of Korea (Seoul, Korea; KCT0004759, http: cris.nih.go.kr, principal investigator: Hyungtae Kim).

Comparison of preemptive and preventive intravenous acetaminophen on opioid consumption in pediatrics undergoing posterior spinal fusion surgery: a randomized controlled trial

Background

Posterior spinal fusion (PSF), commonly used for adolescent idiopathic scoliosis (AIS), causes severe postoperative pain. Intravenous (IV) administration of acetaminophen has shown promise for opioid-sparing analgesia; however, its analgesic effect and optimal timing for its standard use remain unclear. Our study aimed to evaluate the analgesic effect and optimal timing of IV acetaminophen administration in pediatric and adolescent patients undergoing PSF and requiring adequate pain control.

Methods

This prospective, randomized, triple-blind trial was conducted in patients aged 11-20 undergoing PSF. Participants were randomized into three groups: the preemptive group (received IV acetaminophen 15 mg/kg after anesthetic induction/before surgical incision), the preventive group (received IV acetaminophen 15 mg/kg at the end of surgery/before skin closure), and the placebo group. The primary outcome was cumulative opioid consumption during the first 24 h postoperatively.

Results

Among the 99 enrolled patients, the mean ± standard deviation (SD) amount of opioid consumption during the postoperative 24 h was 60.66 ± 23.84, 52.23 ± 22.43, and 66.70 ± 23.01 mg in the preemptive, preventive, and placebo groups, respectively (overall p = 0.043). A post hoc analysis revealed that the preventive group had significantly lower opioid consumption than the placebo group (p = 0.013). However, no significant differences between the groups were observed for the secondary outcomes.

Conclusions

The preventive administration of scheduled IV acetaminophen reduces cumulative opioid consumption without increasing the incidence of drug-induced adverse events in pediatric and adolescent patients undergoing PSF.

Effective remimazolam loading dose for adequate sedation in regional anesthesia

PURPOSE

Remimazolam is a novel ultrashort-acting sedative considered appropriate for continuous infusion during surgical procedures. Nevertheless, information regarding its loading dose for sedation during surgery is limited. We aimed to determine the 90% effective dose (ED90) of the remimazolam loading dose for sedation in patients undergoing limb surgery under regional anesthesia.

METHODS

We included 50 patients aged 19-80 yr undergoing limb surgery under regional anesthesia. After regional anesthesia, remimazolam besylate was administered at the assigned dose. For ten minutes after the initiation of loading, the level of sedation was evaluated using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale. The primary outcome was the ED90 based on whether patients reached a MOAA/S score of ≤ 3 points (loss of response to verbal command) within ten minutes. The secondary outcomes were the ED50 and the estimated effect site and plasma concentration at the time of achieving successful sedation.

RESULTS

In total, 49 patients were included in the final analysis, and adequate sedation with the assigned loading dose was successful in 42 patients. The log-logistic function showed that the ED90 and ED50 were 0.617 mg·kg-1·hr-1 (95% confidence interval [CI], 0.511 to 0.722; 98% CI, 0.492 to 0.741) and 0.438 mg·kg-1·hr-1 (95% CI, 0.335 to 0.541; 98% CI, 0.315 to 0.560), respectively.

CONCLUSION

The ED90 of the remimazolam loading dose to achieve adequate sedation in patients undergoing limb surgery under regional anesthesia was 0.617 mg·kg-1·hr-1 (95% CI, 0.511 to 0.722; 98% CI, 0.492 to 0.741).

STUDY REGISTRATION

ClinicalTrials.gov (NCT05340335); first posted 22 April 2022.

Norepinephrine prevents hypotension in older patients under spinal anesthesia with intravenous propofol sedation: a randomized controlled trial

Reducing hypotension is crucial as hypotension is the most common side effect of spinal anesthesia, and in older patients with various comorbidities, it can lead to fatality. We hypothesized that continuous infusion of norepinephrine could effectively prevent hypotension in older patients undergoing hip surgery under spinal anesthesia with propofol sedation. The study randomly assigned patients aged ≥ 70 years to either a control (Group C, n = 35) or a norepinephrine group (Group N, n = 35). After spinal anesthesia, continuous infusion of propofol and normal saline or norepinephrine was initiated. The number of hypotensive episodes, the primary outcome, as well as other intraoperative hemodynamic events and postoperative complications were compared. In total, 67 patients were included in the final analysis. The number of hypotensive episodes was significantly higher in Group C than in Group N (p < 0.001). Furthermore, Group C required a greater amount of fluid to maintain normovolemia (p = 0.008) and showed less urine output (p = 0.019). However, there was no difference in postoperative complications between the two groups. Continuous intravenous infusion of prophylactic norepinephrine prevented hypotensive episodes, reduced the requirement of fluid, and increased the urine output in older patients undergoing unilateral hip surgery under spinal anesthesia with propofol sedation.Clinical trial registration number: KCT0005046 ( https://cris.nih.go.kr ). IRB number: 2020-0533 (Institutional Review Board of Asan Medical Center, approval date: 13/APR/2020).

Comparison of the Analgesic Efficacy between Arthroscopically Placed Continuous Suprascapular Nerve Block and Ultrasound-guided Continuous Superior Trunk Block: A Double-blinded Randomized Controlled Trial

BACKGROUND

Single-shot suprascapular nerve block and superior trunk block have been reported to provide a noninferior analgesic effect after shoulder surgery with a lesser incidence of hemidiaphragmatic paresis compared with interscalene brachial plexus block. This study hypothesized that continuous suprascapular nerve block provides noninferior analgesia with minimal effects on diaphragmatic movement compared with continuous superior trunk block in patients undergoing arthroscopic shoulder surgery.

METHODS

100 patients were randomized undergoing arthroscopic shoulder surgery between December 2020 and October 2021 into continuous suprascapular nerve block and continuous superior trunk block groups. Before the surgery, patients received either a single-shot superior trunk block or subomohyoid suprascapular nerve block. Thereafter, a superior trunk catheter was inserted by anesthesiologists in patients in the continuous superior trunk block group, and a posterior suprascapular nerve catheter was inserted with arthroscopic assistance during the surgery by surgeon in the continuous suprascapular nerve block group. The primary outcome was the postoperative pain score at postoperative 24 h, and the incidence of hemidiaphragmatic paresis was also compared.

RESULTS

Overall, 98 patients were included in the final analysis. The worst and resting pain scores at postoperative 24 h in the continuous suprascapular nerve block group were inferior compared with those in the continuous superior trunk block group in the test with a noninferiority margin of 1 (worst pain score: mean difference, 0.9; 95% CI, 0.1 to 1.7; resting pain score: mean difference, 0.5; 95% CI, 0.0 to 1.0). However, the continuous suprascapular nerve block group had a significantly lower incidence of hemidiaphragmatic paresis at postoperative 24 h than the continuous superior trunk block group.

CONCLUSIONS

Continuous suprascapular nerve block provides statistically inferior analgesia compared to the continuous superior trunk block; however, the continuous suprascapular nerve block had a minimal effect on the phrenic nerve function.

EDITOR’S PERSPECTIVE

Association of C-reactive protein to albumin ratio with postoperative delirium and mortality in elderly patients undergoing hip fracture surgery: A retrospective cohort study in a single large center

BACKGROUND

Postoperative delirium is a common complication in elderly patients who have undergone hip fracture surgery. Since postoperative delirium is associated with poor outcomes and the treatment is very complicated, identifying the patients at high risk for delirium and providing more attentive care to prevent postoperative delirium is essential. In this study, we aimed to assess the association of an elevated C-reactive protein (CRP)/albumin ratio with the increased incidence of postoperative delirium in elderly people who had undergone hip fracture surgery.

METHODS

A total of 629 patients who underwent hip fracture surgery between January 2014 and December 2018 were retrospectively analyzed. Patients were classified into two groups according to preoperative CRP/albumin cut-off levels (<1.5 and ≥1.5). We performed a propensity score matching analysis to compare the incidence of postoperative delirium and overall mortality between the two groups. Multivariate logistic regression and Cox regression analyses were performed to examine the association of the preoperative CRP/albumin ratio with postoperative delirium and overall mortality.

RESULTS

There were significant differences in the incidence of postoperative delirium (18.0 % vs. 35.8 %, P < 0.001) and overall mortality (26.7 % vs. 46.9 %, P < 0.001) between the groups before matching. We also observed significant differences in the incidence of postoperative delirium (20.7 % vs. 32.7 %, P = 0.019) and overall mortality (34.7 % vs. 46.0 %, P = 0.046) between the groups after matching. A high CRP/albumin ratio (≥1.5) was significantly associated with a higher incidence of postoperative delirium (adjusted odds ratio [OR]: 2.11, 95 % confidence interval [CI]: 1.40-3.18, P < 0.001) and a higher rate of overall mortality (adjusted hazard ratio [HR]: 1.44, 95 % CI: 1.07-1.93, P = 0.015).

CONCLUSION

Preoperative CRP/albumin ratio might be an independent risk factor of postoperative delirium and surgical prognosis in elderly patients undergoing hip fracture surgery.

Predicting Epidural Space Spread Using Ultrasound Color Doppler Imaging in Interlaminar Epidural Steroid Injection: A Prospective Observational Study

BACKGROUND

While the use of fluoroscopy-guided transforaminal epidural steroid injection (TFESI) to help spread the injectate toward the ventral side has increased, this procedure has a radiation risk. Recently, ultrasound has been widely used in the medical field; among ultrasound methods, color Doppler is useful for predicting the direction of the injectate.

OBJECTIVE

This study describes a novel technique employing color Doppler to help predict epidural space spread in interlaminar epidural steroid injection (ILESI).

STUDY DESIGN

Prospective observational study.

SETTING

The study took place at a single pain clinic within a medical center in Jeonju, Republic of Korea.

METHODS

We enrolled 35 patients scheduled for lumbar epidural steroid injection (ESI).  Ultrasound-guided epidural lateral parasagittal interlaminar injection was performed and real-time images using color Doppler were recorded during injections of 5 mL of 0.1% ropivacaine containing contrast dye with dexamethasone 5 mg (1 mL). Fluoroscopy-guided TFESI was performed if it was difficult to perform the procedure based on ultrasound images.

RESULTS

The analysis included 30 images from 30 patients. The observed sensitivity, specificity, positive predictive value, and negative predictive values of the ultrasound color Doppler were 100%, 89.5%, 84.6%, and 100%, respectively. The agreement with ultrasound color Doppler was 93.3%.

LIMITATIONS

The sample size was relatively small.

CONCLUSION

The main advantage of ultrasound-guided ILESI is the lack of radiation exposure and contrast medium requirement. Color Doppler may be a reliable imaging modality to predict epidural space spread during ultrasound-guided ILESI. It is worth predicting the spread in the anterior epidural space (AES) by first attempting ultrasound-guided ESI. If the injectate has not spread to the AES, fluoroscopy-guided TFESI may be a good option after confirming improvement of the patient's symptoms.

Ultrasound-Guided Anterior Approach to a Sciatic Nerve Block: Influence of Lower Limb Positioning on the Visibility and Depth of the Sciatic Nerve

OBJECTIVES

We aimed to identify the optimal lower limb position for an ultrasound (US)-guided anterior approach to a sciatic nerve block.

METHODS

We included 45 patients who met the following criteria: American Society of Anesthesiologists physical status of 1 to 3, age between 18 and 80 years, and scheduled to undergo knee surgery that required a sciatic nerve block. The lower limbs of each patient were placed in the following 4 positions: N, neutral; ER, external rotation of the hip (angle, 45°); ER/F15, ER (angle, 45°) and flexion (angle, 15°) of the hip; and ER/F45, ER (angle, 45°) and F (angle, 45°) of the hip. An investigator acquired US scans of the sciatic nerve in each position, and the visibility score and depth of the sciatic nerve from the skin were analyzed.

RESULTS

The visibility scores were significantly higher in positions ER/F15 and ER/F45 than in positions ER and N (P < .0001). However, there was no difference between the visibility scores in positions ER/F15 and ER/F45 (P = .0959). The depth of the sciatic nerve from the skin decreased with ER and an increase in the F angle of the hip (overall P < .0001).

CONCLUSIONS

Based on the visibility score and depth from the skin, ER of the hip to 45° with a greater F angle (45° versus 15°) of the hip appears to be the optimal position for an US-guided anterior approach to a sciatic nerve block.

Effect of Anesthetic Technique on the Occurrence of Acute Kidney Injury after Total Knee Arthroplasty

Recent studies have reported the advantages of spinal anesthesia over general anesthesia in orthopedic patients. However, little is known about the relationship between acute kidney injury (AKI) after total knee arthroplasty (TKA) and anesthetic technique. This study aimed to identify the influence of anesthetic technique on AKI in TKA patients. We also evaluated whether the choice of anesthetic technique affected other clinical outcomes. We retrospectively reviewed medical records of patients who underwent TKA between January 2008 and August 2016. Perioperative data were obtained and analyzed. To reduce the influence of potential confounding factors, propensity score (PS) analysis was performed. A total of 2809 patients and 2987 cases of TKA were included in this study. A crude analysis of the total set demonstrated a significantly lower risk of AKI in the spinal anesthesia group. After PS matching, the spinal anesthesia group showed a tendency for reduced AKI, without statistical significance. Furthermore, the spinal anesthesia group showed a lower risk of pulmonary and vascular complications, and shortened hospital stay after PS matching. In TKA patients, spinal anesthesia had a tendency to reduce AKI. Moreover, spinal anesthesia not only reduced vascular and pulmonary complications, but also shortened hospital stay.

Staggered Rather Than Staged or Simultaneous Surgical Strategy May Reduce the Risk of Acute Kidney Injury in Patients Undergoing Bilateral TKA

BACKGROUND

The strategy for bilateral total knee arthroplasty (TKA) depends on the timing of surgery for each knee. The purpose of this study was to determine whether the type of surgical strategy for bilateral TKA (staggered, staged, or simultaneous) influences the incidence of acute kidney injury (AKI) and related complications.

METHODS

Enrolled patients from a single tertiary teaching hospital were divided into 3 groups according to the surgical strategy for bilateral TKA: staggered (≤7 days between the first and second procedure; n = 368), staged (8 days to 1 year between the first and second procedure; n = 265), or simultaneous (n = 820). The incidence of AKI as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria was assessed. The rates of major postoperative complications, major adverse cardiovascular and cerebral events, intensive care unit (ICU) admissions, and mortality were also evaluated. To reduce the influence of possible confounding factors, inverse probability of treatment weighting based on propensity-score analysis was used.

RESULTS

The primary outcome was the incidence of AKI according to surgical strategy. The staggered group had a lower rate of AKI compared with the other 2 groups (p < 0.001): 2.4% (9 of 368 patients), 6.0% (16 of 265), and 11.2% (92 of 820) in the staggered, staged, and simultaneous groups, respectively.

CONCLUSIONS

The type of bilateral TKA strategy was an independent risk factor for the development of AKI. The assessment of additional risk factors for the development of AKI is essential before deciding on surgical strategy.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Predicting massive transfusion in adolescent idiopathic scoliosis patients undergoing corrective surgery: Association of preoperative radiographic findings

Corrective surgery with a posterior approach for adolescent idiopathic scoliosis (AIS) is often accompanied by considerable bleeding. Massive transfusion after excessive hemorrhage is associated with complications such as hypothermia, coagulopathy, and acid-base imbalance. Therefore, prediction and prevention of massive transfusion are necessary to improve the clinical outcome of AIS patients. We aimed to identify the factors associated with massive transfusion in AIS patients undergoing corrective surgery. We also evaluated the clinical outcomes after massive transfusion.We included and analyzed AIS patients who underwent corrective surgery with a posterior approach from January 2008 to February 2015. We retrospectively reviewed the electronic medical records of 765 consecutive patients. We performed multivariable logistic regression analysis to assess the factors related to massive transfusion. Furthermore, we compared the effects of massive transfusion on clinical outcomes, including postoperative morbidity and hospital stay.Of 765 patients, 74 (9.7%) received massive transfusion. Body mass index (odds ratio [OR] 0.782, 95% confidence interval [CI] 0.691-0.885, P < .001) and the number of fused vertebrae (OR 1.322, 95% CI 1.027-1.703, P = .03) were associated with massive transfusion. In the comparison among the different Lenke curve types, Lenke type 4 showed the highest prevalence of massive transfusion. Patients in the massive transfusion group showed a higher incidence rate of postoperative morbidity and prolonged hospital stay.Massive transfusion was required in 9.7% of AIS patients who underwent corrective surgery with a posterior approach. A lower body mass index and higher number of fused vertebrae were associated with massive transfusion. Massive transfusion is related to poor clinical outcomes in AIS patients.

Delayed bilateral vocal cord paresis after a continuous interscalene brachial plexus block and endotracheal intubation: A lesson why we should use low concentrated local anesthetics for continuous blocks

RATIONALE

Recurrent laryngeal nerve block is an uncommon complication that can occur after an interscalene brachial plexus block (ISB), which may lead to vocal cord palsy or paresis. However, if the recurrent laryngeal nerve is blocked in patients with a preexisting contralateral vocal cord palsy following neck surgery, this may lead to devastating acute respiratory failure. Thus, ISB is contraindicated in patients with contralateral vocal cord lesion. To the best of our knowledge, there are no reports of bilateral vocal cord paresis, which occurred after a continuous ISB and endotracheal intubation in a patient with no history of vocal cord injury or surgery of the neck.

PATIENT CONCERNS

A 59 year old woman was planned for open acromioplasty and rotator cuff repair under general anesthesia. General anesthesia was induced following an ISB using 0.2% ropivacaine and catheter insertion for postoperative pain control.

DIAGNOSES

While recovering in the postanesthesia care unit (PACU), however, the patient complained of a sore throat and hoarseness without respiratory insufficiency. On the morning of the first postoperative day, she still complained of mild dyspnea, dysphonia, and slight aspiration. She was subsequently diagnosed with bilateral vocal cord paresis following an endoscopic laryngoscopy examination.

INTERVENTIONS

The continuous ISB catheter was immediately removed and the dyspnea and hoarseness symptoms improved, although mild aspiration during drinking water was still present.

OUTCOMES

On the 4th postoperative day, a laryngoscopy examination revealed that the right vocal cord movement had returned to normal but that the left vocal cord paresis still remained.

LESSONS

When ISB is planned, a detailed history-taking and examination of the airway are essential for patient safety and we recommend that any local anesthetics be carefully injected under ultrasound guidance. We also recommend the use of low concentration of local anesthetics to avoid possible paralysis of the vocal cord.

Early postoperative albumin level following total knee arthroplasty is associated with acute kidney injury: A retrospective analysis of 1309 consecutive patients based on kidney disease improving global outcomes criteria

Hypoalbuminemia has been reported to be an independent risk factor for acute kidney injury (AKI). However, little is known about the relationship between the albumin level and the incidence of AKI in patients undergoing total knee arthroplasty (TKA). The aim of our study was to assess incidence and risk factors for AKI and to evaluate the relationship between albumin level and AKI following TKA.The study included a retrospective review of medical records of 1309 consecutive patients who underwent TKA between January 2008 and December 2014. The patients were divided into 2 groups according to the lowest serum albumin level within 2 postoperative days (POD2_alb level < 3.0 g/dL vs ≥3.0 g/dL). Multivariate logistic regression analysis was used to assess risk factors for AKI. A comparison of incidence of AKI, hospital stay, and overall mortality in the 2 groups was performed using propensity score analysis.Of 1309 patients, 57 (4.4%) developed AKI based on Kidney Disease Improving Global Outcomes criteria. Factors associated with AKI included age (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.01-1.09; P = 0.030), diabetes (OR 3.12; 95% CI 1.65-5.89; P < 0.001), uric acid (OR 1.51; 95% CI 1.26-1.82; P < 0.001), beta blocker use (OR 2.65; 95% CI 1.48-4.73; P = 0.001), diuretics (OR 16.42; 95% CI 3.08-87.68; P = 0.001), and POD2_alb level < 3.0 g/dL (OR 1.92; 95% CI 1.09-3.37; P = 0.023). After propensity score analysis, POD2_alb level<3.0 g/dL was associated with AKI occurrence (OR 1.82; 95% CI 1.03-3.24, P = 0.041) and longer hospital stay (P = 0.001).In this study, we demonstrated that POD2_alb level<3.0 g/dL was an independent risk factor for AKI and lengthened hospital stay in patients undergoing TKA.

Encountering unexpected difficult airway: relationship with the intubation difficulty scale

Background

An unexpected difficult intubation can be very challenging and if it is not managed properly, it may expose the encountered patient to significant risks. The intubation difficulty scale (IDS) has been used as a validated method to evaluate a global degree of intubation difficulty. The aims of this study were to evaluate the prevalence and characteristics of unexpected difficult intubation using the IDS.

Methods

We retrospectively reviewed 951 patients undergoing elective surgery in a single medical center. Patients expected to have a difficult intubation or who had history of difficult intubation were excluded. Each patient was assessed by the IDS scoring system with seven variables. Total prevalence of difficult intubation and the contributing individual factors were further analyzed.

Results

For the 951 patients, the difficult intubation cases presenting IDS > 5 was 5.8% of total cases (n = 55). The prevalence of Cormack-Lehane Grade 3 or 4 was 16.2% (n = 154). Most of the difficult intubation cases were managed by simple additional maneuvers and techniques such as stylet application, additional lifting force and laryngeal pressure.

Conclusions

Unexpected difficult airway was present in 5.8% of patients and most was managed effectively. Among the components of IDS, the Cormack-Lehane grade was most sensitive for predicting difficult intubation.

Unilateral postoperative visual loss in a patient undergoing hip arthroscopy in the supine position: a case report

Micro-emboli have been reported to occur commonly during arthroscopic surgery, which is frequently performed as an orthopedic surgical procedure. We here report a patient who experienced unilateral postoperative visual loss after a hip arthroscopy using irrigation fluid in the supine position without any evidence of external compression to either eye throughout the surgical procedure. Retinal fundoscopy suggested that the patient had central retinal artery occlusion, one of the causes of the postoperative visual loss. This case suggests that arthroscopic surgery may pose a substantial risk for paradoxical air embolism, such as central retinal artery occlusion, and suggests the need to prevent the entry of micro-air bubbles during such a type of surgery.

Non-neurologic complications following surgery for scoliosis

BACKGROUND

The purpose of this study was to determine the prevalence of non-neurologic complications following surgery for scoliosis and to identify factors that can increase this risk.

METHODS

The demographic data, medical and surgical histories, and prevalence of non-neurologic complications were reviewed in a retrospective cohort of 602 patients, who had undergone corrective surgery for scoliosis between January 2001 and June 2011.

RESULTS

There were 450 patients under 20 years old (U20) and 152 of patients above 20 years old (A20) enrolled in this study. Forty-nine patients in U20 (10.9%) and 18 patients in A20 (11.8%) had post-operative complications. Respiratory complications were most common in U20 (4%) and gastrointestinal complications were most common in A20 (7%). There was no significant difference between the 2 groups in the prevalence of complications. Logistic regression revealed that factors that correlated with an increased odds for complications were Cobb angle (P = 0.001/P = 0.013, respectively), length of operation time (P = 0.003/P = 0.006, respectively), duration of anesthesia (P < 0.001/P = 0.005, respectively) and transfusion (P = 0.003/P = 0.015, respectively) in U20 and A20. Also, comorbidities (P = 0.021) in U20, and decreased body mass index (P = 0.030), pre-operative forced vital capacity (P = 0.001), forced expired volume in 1s (P = 0.001), increased numbers of vertebrae fused (P = 0.004), blood loss (P = 0.001) in A20 were associated with increased odds for complications.

CONCLUSIONS

There was no difference in the prevalence of complication in scoliosis patients by age. The prevalence of complication was dependent on Cobb angle, length of operation time, duration of anesthesia and transfusion of PRBC. Deterioration of preoperative pulmonary function significantly increased risk of post-operative complications in adult patients.

Comparative prophylactic and therapeutic effects of intravenous labetalol 0.4 mg/kg and nicardipine 20 μg/kg on hypertensive responses to endotracheal intubation in patients undergoing elective surgeries with general anesthesia: a prospective, randomized, double-blind study

BACKGROUND

Laryngoscopy and tracheal intubation (LTI) after induction of general anesthesia often cause hypertension and tachycardia. Labetalol and nicardipine have been used to prevent and treat acute cardiovascular responses to LTI.

OBJECTIVE

The goal of this study was to compare the preventive and therapeutic effects of labetalol 0.4 mg/kg IV and nicardipine 20 μg/kg IV on hypertensive responses to LTI during induction of general anesthesia.

METHODS

Patients undergoing general anesthesia were randomly allocated to 4 groups. In part I (prevention), 80 patients were randomized to receive either 0.4 mg/kg of labetalol (n = 40) or 20 μg/kg of nicardipine (n = 40) 4 minutes before LTI. In part II (treatment), patients were randomized to receive 0.4 mg/kg of labetalol (n = 40) or 20 μg/kg of nicardipine (n = 40) after LTI if hypertension occurred. The number of additional study drug doses required by patients with hypertension (parts I and II) and time to return to normotension (part II) were recorded. Mean arterial pressure and heart rate were monitored, and rate-pressure product was calculated. Adverse events were also monitored.

RESULTS

A total of 130 patients (72 patients in part I and 58 patients in part II) were included in the analysis. In parts I and II, the number of patients who required additional doses of the study drug because of persistent hypertension was lower in the nicardipine groups than in the labetalol groups (P < 0.05). Mean arterial pressure was lower and heart rate was significantly higher over time in the nicardipine groups compared with the labetalol groups (P < 0.05) in parts I and II. In part II, time to return to normotension was shorter in the nicardipine treatment group than in the labetalol treatment group (61 [21] vs 130 [46] seconds; P = 0.01). No statistical differences were observed in the incidence of adverse events except for tachycardia in part I (2 cases in the labetalol prevention group vs 18 cases in the nicardipine prevention group; P = 0.01).

CONCLUSIONS

Patients who received nicardipine were less likely to require additional doses for either the prevention or treatment of hypertensive responses to LTI and responded to the study drug more rapidly than patients who received labetalol for the treatment of hypertensive responses to LTI. However, labetalol was associated with a lower incidence of tachycardia and less of an increase in rate-pressure product when used for the prevention of hypertension during LTI.

Axillary approach versus the infraclavicular approach in ultrasound-guided brachial plexus block: comparison of anesthetic time

Background

With ultrasound guidance, the success rate of brachial plexus block (BPB) is 95-100% and the anesthetic time has become a more important factor than before. Many investigators have compared ultrasound guidance with the nerve stimulation technique, but there are few studies comparing different approaches via the same ultrasound guidance. We compared the axillary BPB with the infraclavicular BPB under ultrasound guidance.

Methods

Twenty-two ASA physical status I-II patients presenting with elective forearm surgery were prospectively randomized to receive an axillary BPB (group AX) or an infraclavicular BPB (group IC) with ultrasound guidance. Both groups received a total of 20 ml of 1.5% lidocaine with 5 µg/ml epinephrine and 0.1 mEq/ml sodium bicarbonate. Patients were then evaluated for block onset and block performance time was also recorded.

Results

Group IC demonstrated a reduction in performance time vs. group AX (622 ± 139 sec vs. 789 ± 131 sec, P < 0.05). But, the onset time was longer in group IC than in group AX (7.7 ± 8.8 min vs. 1.4 ± 2.3 min, P < 0.05). All blocks were successful in both groups.

Conclusions

Under ultrasound guidance, infraclavicular BPB was faster to perform than the axillary approach. But the block onset was slower with the infraclavicular approach.

Autonomic changes in preoperative uncomplicated diabetic patients with postural changes

Diabetic autonomic neuropathy is a critical complication frequently encountered in anaesthetic and surgical practice. Power spectral analysis is a noninvasive tool for monitoring frequency analysis of heart rate variability (HRV) and autonomic control of the heart. This study examined HRV changes in preoperative diabetic patients without overt signs of autonomic dysfunction and in matched controls (n=18 per group). HRV values at -15 degrees, 0 degrees, 15 degrees, 45 degrees and sitting positions were compared between groups and for each position. HRV in diabetic patients was lower than in controls at all positions (absolute units). Low-frequency power (normalized units) and the low-frequency/high-frequency ratio increased significantly at 45 degrees and in sitting positions in controls but not in diabetic patients. Pre-existing autonomic derangements in diabetic patients without overt clinical symptoms can be aggravated by high-degree tilting or sitting positions. Consequently, great care should be taken during the intra- and perioperative management of these patients.

Prophylactic control of post-operative nausea and vomiting using ondansetron and ramosetron after cardiac surgery

BACKGROUND

The aim of this study was to evaluate the efficacy of ondansetron and ramosetron in the reduction of post-operative nausea and vomiting (PONV) associated with patient-controlled analgesia (PCA) after cardiac surgery.

METHODS

A total of 320 patients scheduled for elective cardiac surgery were enrolled. Patients were randomly assigned to one of four treatment regimens (n=80 in each group): no prophylactic antiemetics (group P); intravenous (i.v.) ondansetron 4 mg at the end of surgery and 12 mg added to PCA (group O); i.v. ramosetron 0.3 mg at the end of surgery and no antiemetics added to PCA (group R1); and i.v. ramosetron 0.3 mg at the end of surgery and 0.6 mg added to PCA (group R2).

RESULTS

The incidence of PONV during the 48-h post-operative period was lower in groups O (46%), R1 (54%), and R2 (35%) compared with group P (71%, P<0.001). The incidence and severity of nausea were lower in groups O, R1, and R2 than in group P during the 24-h post-operative period, whereas the incidence and severity of nausea during 24-48 h after surgery were lower in groups O and R2, but not in group R1, than in group P. Compared with group P (53%), the frequency of rescue antiemetic usage was significantly lower in groups O (34%) and R2 (29%), but not in group R1 (43%).

CONCLUSION

The addition of either ondansetron or ramosetron to PCA can reduce the incidence of PONV during 48 h after cardiac surgery.

Warming the epidural injectate improves first sacral segment block: a randomised double-blind study

This study investigated the effect of local anaesthetic temperature on block of the first sacral segment. Twenty-four patients undergoing lumbar epidural anaesthesia at L2-3 or L3-4 were randomly divided in double-blind fashion into two groups to receive 22 ml of lignocaine 2% with adrenaline 1:200,000, sodium bicarbonate and fentanyl, at either 21 degrees C (cold group) or 37 degrees C (warm group). The sensory block was assessed by loss of sensation to pinprick and the pain threshold after repeated electrical stimulation at L2, S1 and S3 dermatomes. Motor block was evaluated using the modified Bromage scale. Patient characteristics were comparable between the groups. Onset of block at the first sacral segment (S1) was faster in the warm group than in the cold (10 vs. 17.5 minutes, P < 0.001). The pain threshold at S1 was significantly higher in the warm group. We concluded that epidural lignocaine 2% with adrenaline 1:200,000, sodium bicarbonate and fentanyl injected at 370C hastens SI block within 10 minutes of administration.

Elongation of the Trachea During Neck Extension in Children: Implications of the Safety of Endotracheal Tubes

During neck extension, the changes in distance between endotracheal tube (ETT) tip and carina may not be equal to the changes in distance between vocal cords and ETT tip because of tracheal elongation. These distances are directly related to extubation risk. Using a fiberoptic bronchoscope, the distance between ETT tip and carina was measured in the neutral position after full extension of the neck in 25 children (2-8 yr old) scheduled for elective surgery under general anesthesia. The tracheal length was then measured in the neutral position and after full extension. The distance between vocal cords and ETT tip was calculated as the tracheal length minus the distance between ETT tip and carina. After full extension, the tracheal length (7.97 +/- 0.85 cm) was increased by 0.95 +/- 0.43 cm, and the change in distance between vocal cords and ETT tip was -1.08 +/- 0.47 cm, whereas the change in distance between ETT tip and carina was 2.02 +/- 0.58 cm. These results suggest that neck extension actually displaces the ETT tip to the vocal cords, increasing the risk of tracheal extubation in older children, although the actual displacement of ETT tip to vocal cords is reduced by tracheal lengthening.

IMPLICATIONS

The distance between endotracheal tube tip and vocal cords is directly related to the risk of exubation. Despite tracheal elongation, neck extension actually displaced the endotracheal tube tip to the vocal cords in older children.

The effect of acute normovolemic haemodilution on cerebral oxygenation

Acute normovolemic haemodilution (ANH) may cause an imbalance in cerebral oxygen metabolism because it decreases the arterial oxygen content. This study was designed to investigate the effect of ANH on cerebral oxygenation. By using cerebral oximetry, the regional cerebral oxygen saturation (rSO2) was monitored during ANH in 26 patients without systemic illness (initial haematocrit = 42 +/- 1%). The rSO2 did not show a significant change until the Hct reached >30%. However, it decreased significantly thereafter to reach 88% of the baseline value when the ANH was completed with a Hct value of 24 +/- 1% (before ANH; 71 +/- 6% vs. after ANH; 62 +/- 4%, p < 0.01). In conclusion, an ANH can lead to a reduction in cerebral oxygenation when a patient's Hct goes below 30%.

Efficacy of Prophylactic Ondansetron in a Patient-Controlled Analgesia Environment

We conducted a prospective, randomized, double-blind, placebo-controlled trial to examine the efficacy of prophylactic ondansetron on post-operative nausea and vomiting (PONV) during opioid patient-controlled analgesia (PCA). In total, 374 patients using opioid PCA, but otherwise considered to be low risk for PONV, were randomly allocated to ondansetron (4 mg given intravenously and 16 mg added into the PCA pump) or saline (control group). PONV was evaluated in terms of nausea graded on a visual analogue scale, and the number of patients who experienced emetic episodes or needed rescue anti-emetics in the 48-h post-operative period. Patient satisfaction for PCA was scored at the end of the evaluation period. The only difference between the two groups was the higher number of headaches in the ondansetron group. In patients using opioid PCA, but with no other high risk factors for PONV, prophylactic ondansetron does not have any clinical benefit.

Combined use of autologous transfusion techniques to avoid allogeneic transfusion in spinal fusion surgery with instrumentation

This study conducted a retrospective review of the medical records of 321 patients to delineate the efficacy of the combined use of autologous transfusion (AT) techniques. Transfusion profiles between an AT and homologous transfusion (HT) group were compared. A much lower proportion of patients were exposed to allogeneic blood in the AT group (13%) than in the HT group (98%, p<0.001). In the AT group, a significantly smaller proportion of patients were exposed to allogeneic blood in patients transfused with three or four AT techniques (8%) than those with one or two techniques (29%, p<0.05). A febrile reaction (11% of patients) after a reinfusion of post-operatively shed blood was the only side effect associated with an AT. In conclusion, an AT is effective for preventing the exposure of allogeneic blood in spinal fusion surgery. The combined use of multiple AT techniques may further improve its efficacy.

Effects of Ethanol on the Rat Glutamate Excitatory Amino Acid Transporter Type 3 Expressed in Xenopus Oocytes: Role of Protein Kinase C and Phosphatidylinositol 3-Kinase

BACKGROUND

Glutamate is a major excitatory neurotransmitter in the central nervous system. Glutamate transporters play a critical role in maintaining extracellular glutamate concentrations. We investigated the effects of ethanol on a neuronal glutamate transporter, excitatory amino acid transporter type 3 (EAAT3), and the role of protein kinase C (PKC) and phosphatidylinositol 3-kinase (PI3 K) in mediating these effects.

METHODS

EAAT3 was expressed in Xenopus oocytes by injection of EAAT3 messenger RNA. By using a two-electrode voltage clamp, membrane currents were recorded after the application of l-glutamate. Responses were quantified by integration of the current trace and reported as microcoulombs. Data are mean +/- SEM.

RESULTS

Ethanol enhanced EAAT3 activity in a concentration-dependent manner. At 25, 50, 100, and 200 mM of ethanol, the responses were significantly increased compared with control values. Kinetic study demonstrated that ethanol (50 mM) significantly increased Vmax (3.48 +/- 0.2 microC for control versus 4.16 +/- 0.24 microC for ethanol; n = 19; p < 0.05) without a significant change in the Km (65.6 +/- 11.1 microM for control versus 55.8 +/- 9.6 microM for ethanol; n = 19; p > 0.05) of EAAT3 for glutamate. Preincubation of the oocytes with phorbol-12-myristate-13-acetate (PMA) significantly increased EAAT3 activity (0.98 +/- 0.08 muC for control versus 1.28 +/- 0.09 microC for ethanol; n = 19; p < 0.05). However, there was no statistical difference among the responses of EAAT3 to PMA, ethanol, or PMA plus ethanol. Although the PKC inhibitors chelerythrine and staurosporine did not decrease the basal EAAT3 activity, they abolished the enhancement of EAAT3 activity by ethanol. Pretreatment with wortmannin, a PI3 K inhibitor, also abolished the ethanol-enhanced EAAT3 activity.

CONCLUSIONS

These results suggest that acute ethanol exposure increases EAAT3 activity at clinically relevant concentrations and that PKC and PI3 K may be involved in mediating these ethanol effects.

Regulation of interleukin-4 on collagen gene expression by systemic sclerosis fibroblasts in culture

This study was performed to evaluate the transcriptional regulation of interleukin-4 (IL-4) on collagen gene expression in systemic sclerosis (SSc) fibroblasts. The pro alpha 2(I) collagen promotor activity has been examined by transfection experiments and chloramphenicol acetyl transferase (CAT) assay. Maximal elevation of collagen synthesis was presented at a concentration of 5 ng/ml of IL-4. In the CAT assay, the percentage of acetylation was 7.0% +/- 2.0% in untreated controls and 12.5% +/- 3.5% in SSc fibroblasts at 5.0 ng/ml of IL-4. In normal skin (NS), 3.5% +/- 1.0%, and 10.2% +/- 2.5% were acetylated, respectively. The promoter activity was increased 1.8 +/- 0.7-fold and 2.9 +/- 1.3-fold in IL-4-treated SSc and NS, respectively, as compared to untreated groups. In Northern and dot-blot analysis, the level of types I and III collagen mRNA increased 1.1 +/- 0.3-fold and 1.3 +/- 0.3-fold, respectively, in IL-4-treated SSc fibroblasts compared to 3.0 +/- 0.4-fold and 3.0 +/- 0.3-fold, respectively, in NS fibroblasts. These data may indicate that IL-4 could be important in promoting biogenesis of collagen proteins by increased stability and transcription of the collagen mRNA. Also, transcriptional activation of collagen gene expression appears to have a less sensitive effect on SSc than on NS.

Effects of x-irradiation on survival and extracellular matrix gene expression of cultured keloid fibroblasts

Survival and extracellular matrix gene expression were studied by viable cell count assay and Northern transfer analysis to compare the sensitivity of normal skin and keloid fibroblasts towards x-irradiation. As the dosage of radiation increased, the numbers of viable cells in irradiated groups were remarkably decreased exponentially, with no significant difference between normal and keloid cell lines. By Northern blot analysis, there was no change in size of the mRNAs for pro alpha 1(I) collagen, fibronectin and beta-actin. By slot-blot hybridization, pro alpha 1(I) collagen mRNA levels in x-irradiated fibroblasts were markedly decreased compared with non-irradiated controls. The amounts of fibronectin and beta-actin mRNAs were also decreased. This study suggests that both normal skin and keloid fibroblasts are sensitive to x-irradiation, and that extracellular matrix gene expression is also affected by such exposure.

The effect of thermal biofeedback and progressive muscle relaxation training in reducing blood pressure of patients with essential hypertension

In order to assess the effectiveness of the thermal biofeedback training combined with the progressive muscle relaxation therapy in the treatment of patients with essential hypertension, blood pressure decline was measured on the treatment group who had the combined thermal biofeedback and progressive muscle relaxation training (N = 11), and on the control group who had only the progressive muscle relaxation training (N = 8). Baseline blood pressure was measured four times for two weeks on both groups. For the treatment group, blood pressure was measured twice before and after each of eight sessions of thermal biofeedback training for four weeks. For the control group, blood pressure was measured every two visits to a clinic for progressive muscle relaxation self-training twice before and after the self-training. A significant decline of the systolic blood pressure by 20.6 mmHg and of the diastolic blood pressure by 14.4 mmhg was observed in the treatment group. There was a tendency for both blood pressures to increase in the control group.

[Differences in the characteristics of hospital stress between medical and surgical patients]

This study explored differences in how medical and surgical patients compare on the degree of hospital stress and their subjective physical status. Subjects were 343 medical and surgical patients in five university hospitals in Seoul and Taegu. They responded to the Hospital Stress Rating Scale and a self-report on physical status. The controlled variables were age, education, number of previous hospitalizations and seriousness of the illness. Medical and surgical patient differences on nine factors of the hospital stress scale and nine areas of physical conditions were reported as follows explored: 1. 1) There was not a statistically significant difference at the .05 level in the total mean score for hospital stress between medical patients and surgical patients. 2) The mean score of the factor lack of information (M=2.308) for medical patients was higher than the mean score (M=2.064) of the surgical patients. 3) The mean scores of the factor of discomfort (M=2.130), loss of independence (M=1.889) for surgical patients were higher than for medical patients. 2. 1) There was a statistically significant difference at the .05 level in the total mean score for physical status between medical patients and surgical patients. 2) The mean scores were lower in subjective physical status for surgical patients (S) than for medical patients (M); stomach condition (S:M=2.8433, M:M=3.0000), self-assistance (S:M=3.0373, M:M=3.4498), movement (S:M=2.6716, M:M=3.2392), interest in your surroundings (S:M=3.0522, M:M=3.2632).(ABSTRACT TRUNCATED AT 250 WORDS)

[Discrepancy in the scores of uncertainty perceived by patients and nurses' interperson perception]

The purpose of this study was to assess and compare discrepancy in the scores of uncertainty perceived by patients and nurses' interperson perception. For this study, 124 hospitalized patients and the same numbered nurses assigned for direct care of each 124 patients were selected from general ward of C. University Hospital in Seoul during the time period from September to November 1987. Degree of uncertainty was measured by 27 items modified from Mishel Uncertainty in Illness Scale (M-UIS), and was utilized by a Likert type scale The data were analysed by Mcnemar-test, Unpaired t-test, ANOVA, Scheffé-test and Stepwise multiple regression. The results are summarized as follows: 1. The discrepancy in the scores of uncertainty perceived by patients and nurses' interperson perception showed significant differences in 23 of 27 items: 11 of 23 items showed that the scores of patients' perception of uncertainty were higher than that of nurses' interperson perception of uncertainty. but 12 of 23 items were revealed reversely. 2. With regard to nurse's demographic variables, the discrepancy scores were the highest in the group under 22 years of age (F = 3.20, p = .026) and in the group less than 1 year of nursing experience among 4 groups (F = 4.41, p = .006). 3. The discrepancy scores had a tendency to be lowered in the higher age group (r = .27, p = .0026) and in the longer experienced group (r = .25, p = .0052).(ABSTRACT TRUNCATED AT 250 WORDS)