Perioperative management of left ventricular diastolic dysfunction and heart failure: an anesthesiologist's perspective / 대한마취과학회지

Anesthesiologists frequently see asymptomatic patients with diastolic dysfunction or heart failure for various surgeries. These patients typically show normal systolic function but abnormal diastolic parameters in their preoperative echocardiographic evaluations. The symptoms that are sometimes seen are similar to those of chronic obstructive pulmonary disease. Patients with diastolic dysfunction, and even with diastolic heart failure, have the potential to develop a hypertensive crisis or pulmonary congestion. Thus, in addition to conventional perioperative risk quantification, it may be important to consider the results of diastolic assessment for predicting the postoperative outcome and making better decisions. If anesthesiologists see female patients older than 70 years of age who have hypertension, diabetes, chronic renal disease, recent weight gain, or exercise intolerance, they should focus on the patient's diastologic echocardiography indicators such as left atrial enlargement or left ventricular hypertrophy. In addition, there is a need for perioperative strategies to mitigate diastolic dysfunction-related morbidity. Specifically, hypertension should be controlled, keeping pulse pressure below diastolic blood pressure, maintaining a sinus rhythm and normovolemia, and avoiding tachycardia and myocardial ischemia. There is no need to classify these diastolic dysfunction, but it is important to manage this condition to avoid worsening outcomes.

Adsorption of desflurane by the silica gel filters in breathing circuits: an in vitro study / 대한마취과학회지

BACKGROUND: During general anesthesia, a heated breathing circuit (HBC) is used to replace the heat and moisture exchange function of the upper airway. One HBC uses an air dryer filter that employs silica gel (SG) as a desiccant. SG is capable of adsorbing many organic compounds. Therefore, we undertook an in vitro study of the adsorption of desflurane by SG filters. METHODS: An HBC was connected to an anesthesia machine, and a test lung was connected to the circuit. The test lung was mechanically ventilated with 2 or 4 L/min of fresh gas flow, with and without the air dryer filter. Desflurane was administered at a 6 vol% on the vaporizer dial setting. The experiment was repeated 15 times in each group. The end-tidal concentrations were measured during the experiments. The air dryer filter weights were measured before and after the experiments, and the times required to achieve the specific end-tidal desflurane concentrations were determined. RESULTS: Significant differences in the end-tidal concentrations of desflurane were observed between the control and filter groups (P < 0.001). The filter weights increased significantly after the experiments (P < 0.001). The times required to achieve the same end-tidal desflurane concentrations were different with the application of the air dryer filter (P < 0.001). CONCLUSIONS: The adsorption of desflurane with the use of an air dryer filter was verified in this in vitro study. Careful attention is needed when using air dryer gel filters during general anesthesia.

Role of calcium channels responsible for phenylephrine-induced contraction in rat aorta 3 days after acute myocardial infarction / 대한마취과학회지

BACKGROUND: Phenylephrine (PE) produces tonic contraction through involvement of various calcium channels such as store-operated calcium channels (SOCCs) and voltage-operated calcium channels (VOCCs). However, the relative contribution of each calcium channel to PE-induced contraction has not been investigated in isolated rat aorta of early acute myocardial infarction (AMI). METHODS: Endothelium-denuded rat aortic rings from rats 3 days after AMI or sham-operated (SHAM) rats were prepared in an organ chamber with Krebs-Ringer bicarbonate solution for isometric tension recording. We assessed the PE dose-response relationships in 2.5 mM calcium medium for both groups. The same procedure was repeated using rings pretreated with the SOCC inhibitor 2-aminoethoxydiphenyl borate, sarco/endoplasmic-reticulum calcium ATPase inhibitor thapsigargin (TG), diacyl glycerol lipase inhibitor RHC80267, and sodium-calcium exchanger inhibitor 3,4-dichlorobenzamil hydrochloride for 30 minutes before addition of calcium. When ongoing tonic contraction was sustained, dose-response curves to the VOCC inhibitor nifedipine were obtained to assess the relative contribution of each calcium channel under various conditions. RESULTS: The effect of SOCC induction with TG pretreatment on PE-induced contraction was significantly lower in the AMI group compared to the SHAM group. In addition, there were significant decreases in the sensitivity and efficacy of the VOCC inhibitor nifedipine on PE-induced contraction in the AMI group. CONCLUSIONS: Results suggest that the change of vascular reactivity of PE in rat aorta 3 days after AMI is characterized by a decreased contribution of L-type VOCCs. The enhanced VOCC-independent calcium entry mechanisms after AMI can be mediated by enhanced capacitative calcium entry through the activation of SOCCs.

Volume-controlled versus pressure-controlled ventilation-volume guaranteed mode during one-lung ventilation / 대한마취과학회지

BACKGROUND: The purpose of this study was to investigate the changes in airway pressure and arterial oxygenation between ventilation modes during one-lung ventilation (OLV) in patients undergoing thoracic surgery. METHODS: We enrolled 27 patients for thoracic surgery with OLV in the lateral decubitus position. The subjects received various modes of ventilation in random sequences during surgery, including volume-controlled ventilation (VCV) and pressure-controlled ventilation-volume guaranteed (PCV-VG) with a tidal volume (TV) of 8 ml/kg of actual body weight. Target-controlled infusion (TCI) with propofol and remifentanil was used for anesthesia induction and maintenance. After double-lumen endobronchial tube (DLT) insertion, the proper positioning of the DLT was assessed using a fiberoptic bronchoscope. Peak inspiratory pressure (Ppeak), exhaled TV, and arterial blood gas were measured 30 min after each ventilation mode. RESULTS: P(peak) was significantly reduced with the PCV-VG mode (19.6 +/- 2.5 cmH2O) compared with the VCV mode (23.2 +/- 3.1 cmH2O) (P < 0.000). However, no difference in arterial oxygen tension was noted between the groups (PCV-VG, 375.8 +/- 145.1 mmHg; VCV, 328.1 +/- 123.7 mmHg) (P = 0.063). The exhaled TV was also significantly increased in PCV-VG compared with VCV (451.4 +/- 85.4 vs. 443.9 +/- 85.9 ml; P = 0.035). CONCLUSIONS: During OLV in patients with normal lung function, although PCV-VG did not provide significantly improved arterial oxygen tension compared with VCV, PCV-VG provided significantly attenuated airway pressure despite significantly increased exhaled TV compared with VCV.

Volume-controlled versus pressure-controlled ventilation-volume guaranteed mode during one-lung ventilation / 대한마취과학회지

BACKGROUND: The purpose of this study was to investigate the changes in airway pressure and arterial oxygenation between ventilation modes during one-lung ventilation (OLV) in patients undergoing thoracic surgery. METHODS: We enrolled 27 patients for thoracic surgery with OLV in the lateral decubitus position. The subjects received various modes of ventilation in random sequences during surgery, including volume-controlled ventilation (VCV) and pressure-controlled ventilation-volume guaranteed (PCV-VG) with a tidal volume (TV) of 8 ml/kg of actual body weight. Target-controlled infusion (TCI) with propofol and remifentanil was used for anesthesia induction and maintenance. After double-lumen endobronchial tube (DLT) insertion, the proper positioning of the DLT was assessed using a fiberoptic bronchoscope. Peak inspiratory pressure (Ppeak), exhaled TV, and arterial blood gas were measured 30 min after each ventilation mode. RESULTS: P(peak) was significantly reduced with the PCV-VG mode (19.6 +/- 2.5 cmH2O) compared with the VCV mode (23.2 +/- 3.1 cmH2O) (P < 0.000). However, no difference in arterial oxygen tension was noted between the groups (PCV-VG, 375.8 +/- 145.1 mmHg; VCV, 328.1 +/- 123.7 mmHg) (P = 0.063). The exhaled TV was also significantly increased in PCV-VG compared with VCV (451.4 +/- 85.4 vs. 443.9 +/- 85.9 ml; P = 0.035). CONCLUSIONS: During OLV in patients with normal lung function, although PCV-VG did not provide significantly improved arterial oxygen tension compared with VCV, PCV-VG provided significantly attenuated airway pressure despite significantly increased exhaled TV compared with VCV.

Peripheral nerve injury caused by needle impalement: Synchrotron small-angle X-ray scattering study in ex-vivo rat sciatic nerve

BACKGROUND: Direct puncture by a needle is a risk factor for nerve damage. This study was designed to demonstrate nerve damage caused by a needle using the synchrotron small-angle X-ray scattering (SAXS) technique. METHODS: A 15 mm section of rat (Male Spargue-Dawley, about 250 grams) sciatic nerves were involved in this study. The nerve specimen for the experiment (N = 5) was punctured 5 times by a needle (25 G, 100 beveled) under general anesthesia with enflurane. The needle was placed perpendicular to the nerve and the needle bevel was placed parallel to the nerve. The SAXS patterns of the punctured nerves, extracted about 15 min prior to the experiment, were acquired after 1 week. The SAXS patterns of a normal sciatic nerve (N = 5), extracted about 15 min prior to the experiment, were measured in order to provide a comparison. Experiments were carried out at 4C1 beamline at Pohang Accelerator Laboratory in Korea. Incoming X-rays were monochromatized at 11 keV using a double multilayer (WB4C) monochromator; the beam size was around 0.5 (V) x 0.8 (H) mm2. The exposure time was 60 sec, and 8 to 12 images were acquired per sample with a 0.5 mm interval. RESULTS: In the punctured group, the periodic peaks of myelin sheath and collagen fiber were not changed. However, the periodic peaks of interfibrillar distance of collagen were greatly changed. CONCLUSIONS: Direct needle-nerve impalement did not cause damages in myelin sheath and collagen fibers when the needle was placed perpendicular and the needle bevel paralleled to the nerve fiber. This result can imply that the needle slipped into the interfibrillar packing of collagen fibrils.

Hypotensive bradycardic events during shoulder arthroscopic surgery under interscalene brachial plexus blocks / 대한마취과학회지

Sudden, profound hypotensive and bradycardic events (HBEs) have been reported in more than 20% of patients undergoing shoulder arthroscopy in the sitting position. Although HBEs may be associated with the adverse effects of interscalene brachial plexus block (ISBPB) in the sitting position, the underlying mechanisms responsible for HBEs during the course of shoulder surgery are not well understood. The basic mechanisms of HBEs may be associated with the underlying mechanisms responsible for vasovagal syncope, carotid sinus hypersensitivity or orthostatic syncope. In this review, we discussed the possible mechanisms of HBEs during shoulder arthroscopic surgery, in the sitting position, under ISBPB. In particular, we focused on the relationship between HBEs and various types of syncopal reactions, the relationship between HBEs and the Bezold-Jarisch reflex, and the new contributing factors for the occurrence of HBEs, such as stellate ganglion block or the intraoperative administration of intravenous fentanyl.

Intravenous fentanyl during shoulder arthroscopic surgery in the sitting position after interscalene block increases the incidence of episodes of bradycardia hypotension / 대한마취과학회지

BACKGROUND: Episodes of bradycardia hypotension (BH) or vasovagal syncope have a reported incidence of 13-29% during arthroscopic shoulder surgery in the sitting position after an interscalene block (ISB). This study was designed to investigate whether intravenous fentanyl during shoulder arthroscopy in the sitting position after ISB would increase or worsen the incidence of BH episodes. METHODS: In this prospective study, 20 minutes after being in a sitting position, 160 patients who underwent ISB were randomized to receive saline (S, n = 40), 50 microg of fentanyl (F-50, n = 40), 100 microg of fentanyl (F-100, n = 40) or 30 mg of ketorolac (K-30, n = 40) randomly. We assessed the incidence of BH episodes during the operation and the degree of maximal reduction (Rmax) of blood pressure (BP) and heart rate (HR). RESULTS: The incidence of BH episodes was 10%, 15%, 27.5% and 5% in the S, F-50, F-100 and K-30 groups, respectively. Mean Rmax of systolic BP in the F-100 group was significantly decreased as compared to the S group (-20.0 +/- 4.5 versus -6.3 +/- 1.6%, P = 0.004). Similarly, mean Rmax of diastolic BP in the F-100 group was also significantly decreased (P = 0.008) as compared to the S group. CONCLUSIONS: These results suggest that fentanyl can increase the incidence of BH episodes during shoulder arthroscopic surgery in the sitting position after ISB.

Femoral and sciatic nerve blocks for total knee replacement in an obese patient with a previous history of failed endotracheal intubation: A case report

Peripheral nerve block has frequently been used as an alternative to epidural analgesia for postoperative pain control in patients undergoing total knee replacement. However, there are few reports demonstrating that the combination of femoral and sciatic nerve blocks (FSNBs) can provide adequate analgesia and muscle relaxation during total knee replacement. We experienced a case of successful FSNBs for a total knee replacement in a 66 year-old female patient who had a previous cancelled surgery due to a failed tracheal intubation followed by a difficult mask ventilation for 50 minutes, 3 days before these blocks. FSNBs were performed with 50 ml of 1.5% mepivacaine because she had conditions precluding neuraxial blocks including a long distance from the skin to the epidural space related to a high body mass index and nonpalpable lumbar spinous processes. This case suggests that FSNBs can provide a good alternative anesthetic method for total knee replacement.

Predicting the difficulty in performing a neuraxial blockade / 대한마취과학회지

BACKGROUND: Traumatic placement of a needle during a neuraxial blockade has been related to many complications such as postdural puncture headache, trauma to neural structures and even spinal hematoma, causing permanent neurologic deficits. Although efforts to minimize the complications caused by traumatic neuraxial blockade have been made, nothing was found to be clear. The authors investigated the predictors of difficult neuraxial blockade using the first puncture success and number of attempts as measures to assess the difficulty. METHODS: In this prospective observational study, 253 patients scheduled for elective surgery underwent spinal or epidural anesthesia. Patient data (age, sex, height, weight, body mass index, and quality of anatomical landmarks), the provider's level of experience, type of blockade (spinal or epidural), needle type/gauge and the distance from skin to subarachnoid or epidural space were recorded. Significant variables were first determined by Student's t-test and Pearson's chi square test and then logistic and Poisson regression tested the association of the first puncture success and number of attempts with the significant variables. RESULTS: The provider's level of experience and the distance from skin to subarachnoid or epidural space were significant in logistic and Poisson regression. Body mass index was significant only in Poisson regression and the quality of anatomical landmarks was significant only in logistic regression. CONCLUSIONS: Provider's level of experience and the distance from skin to subarachnoid or epidural space influenced the difficulty in performing a neuraxial blockade.

Cardiac arrest induced by the local infiltration of epinephrine during desflurane anesthesia: A case report

Topical epinephrine is useful to reduce bleeding and to give a clear operative field during general anesthesia. However, epinephrine at clinical doses has adverse cardiovascular effects, such as transient hypertension and arrhythmia. We report a case of cardiac arrest following the local infiltration of epinephrine during desflurane anesthesia. The patient recovered without sequelae after intensive care. However, it is recommended that caution is exercised when the local infiltration of epinephrine is used during general anesthesia.

An unusual systemic toxicity of mepivacaine following axillary brachial plexus block or femoral/sciatic nerve block in patients with chronic renal failure and/or hypertension: A report of 2 cases

There are few reports about the systemic toxicity of mepivacaine, which is widely used for regional nerve blocks, because of its short onset time and intermediate duration, during or after blockades. We report two cases. In the first, a 70 year-old female with chronic renal failure and hypertension was scheduled for arteriovenous fistula formation under axillary brachial plexus block using 30 ml of 1.5% mepivacaine. In the second, a 69 year-old female with hypertension who was scheduled for total knee replacement under femoral/sciatic nerve block with lateral femoral cutaneous nerve block using 45 ml of 1.5% mepivacaine. Both had an exaggerated hemodynamic response (of increased blood pressure and heart rate) with symptoms and signs of central nervous system excitation not evolving to convulsions, which was induced by mepivacaine during or soon after the blockades. Possible causes and mechanisms of the events are discussed based on the literature.

Pulsed Radiofrequency Treatment of the Supraorbital and Supratrochlear Nerve in a Case of Trigeminal Neuralgia: A case report

Pharmacological management is the first choice for treatment of the trigeminal neuralgia patients; however, if this mode of treatment fails a minimally invasive procedure should be performed. One of the most commonly used procedures is conventional radiofrequency lesioning of the Gasserian ganglion. Despite its popularity and success rate, this technique has disadvantages such as diminished corneal reflex, masseter weakness, numbness and anesthesia dolorosa. As a result, many studies have been conducted in an attempt to find a better method of treating trigeminal neuralgia. We report here a case of a trigeminal neuralgia patient that was treated with pulsed radiofrequency lesioning of the supraorbital and supratrochlear nerve due to pain in the frontal head that was refractory to the pharmacological treatments. Following the procedure, the Visual Analogue Scale score for pain decreased to 1-2/10 and the pain relief persisted for 7 months. These results indicate that pulsed radiofrequency treatment of the peripheral nerve may be useful for trigeminal neuralgia patients that do not respond to pharmacological treatments.

Combined femoral and popliteal sciatic nerve blocks versus epidural anesthesia in great saphenous veins stripping surgery with multiple stab avulsion / 대한마취과학회지

BACKGROUND: This study was designed to test the hypothesis that a combined femoral and politeal sciatic nerve blocks (FPSNB) would have excellent clinical properties and better patient satisfaction than epidural anesthesia for the great saphenous veins stripping (GSVS) surgery with multiple stab avulsion (MSA). METHODS: Sixty patients were allocated into two groups. The epidural group received epidural anesthesia with 15 ml of 0.75% ropivacaine (n = 30), and the FPSNB group received a combined FPSNB with 25 ml of 1.5% mepivacaine with a nerve stimulator (n = 30). We assessed the anesthetic and postoperative records. A questionnaire-based study including patient satisfaction for anesthetic techniques (100 point scale) was conducted 3 days postoperatively by a blinded observer. RESULTS: The time from initial injection to the start of surgery and the duration of sensory blockade were not different between groups (P > 0.05). The percentage of patients with anesthesia-related complications in epidural anesthesia was 33.3%, 46.6%, 23.3% and 20% for shivering, hypotension, bradycardia and postoperative voiding difficulty, respectively. FPSNB did not produce these complications. Additional analgesia with 50-100 microgram of fentanyl was more frequently used in FPSNB (60% vs 6.7%, FPSNB vs Epidural group, P < 0.01), but patient satisfaction of FPSNB was higher than epidural anesthesia (88.1 +/- 13.2 vs 76.5 +/- 15.8, FPSNB vs Epidural group, P < 0.01). CONCLUSIONS: A combined FPSNB with a small amount of narcotics is an adequate anesthetic technique for unilateral GSVS surgery with MSA.

Injury to the spinal cord by a thoracic epidural catheter used to control postpneumonectomy pain : A case report / 대한마취과학회지

A thoracotomy is one of the most severe painful operations. This severe pain can usually be controlled by thoracic epidural analgesia. Epidural catheterization for analgesia has several complications, e.g., epidural hematoma, abscess, spinal stenosis, spinal infarction, direct cord trauma, and neurotoxicity by chemical contamination. These complications can cause acute paraplegia, but permanent paraplegia is extremely rare. We report a case of paresthesia and temporary paralysis in a 54-year-old patient who suffered spinal cord injury after thoracic epidural catheterization for the control of postpneumonectomy pain under general anaesthesia.

The perioperative management of a patient with lowe syndrome for general anesthesia: A case report / 대한마취과학회지

Lowe syndrome (the oculo-cerebro-renal syndrome of Lowe, OCRL) is a multi-system disorder that affects the eyes, nervous system, and kidney. OCRL is a rare X-linked recessive disease with a prevalence of approximately 1 : 500,000. The clinical features of OCRL include congenital cataracts, growth and mental retardation, areflexia, hypotonia, and renal tubular dysfunction (Fanconi-type). Chronic metabolic acidosis and hypotonia may be the most important component affecting management of the peri-anesthetic period during general anesthesia. However, problems such as electrolyte imbalance, seizure, fragility of the bone structures, and increased intraocular pressure should also be considered during the perioperative period. We report here the perioperative management of a patient with Lowe syndrome during the removal of multiple scalp cysts under general anesthesia.

Total Intravenous Anesthesia for Open Heart Surgery in a Patient with a Moyamoya Disease: A case report / 대한마취과학회지

Moyamoya disease (MMD) is a progressive cerebrovascular occlusive disease of the internal carotid arteries and anterior and middle cerebral arteries. Non-neurological surgery in patients with MMD is often complicated by cerebral ischemia or infarction. The goals of perioperative management are to maintain normotension, normocarpnia, normovolemia and normothermia. Here we report a case of a patient with MMD who underwent patch closure of an atrial septal defect and pulmonary valvotomy by use of a normothermic and non-hemodiluted cardiopulmonary bypass. To prevent intraoperative neurological complications we performed total intravenous anesthesia with propofol, made burst suppression in EEG and monitored the jugular bulb oxygen saturation (SjvO2) for cerebral desaturation.

Comparison between Bolus Injection and Continuous Infusion of Ondansetron on Nausea and Vomiting in Intravenous, Patient-controlled Analgesia after Laparoscopic-assisted Vaginal Hysterectomy using Propofol and Remifentanil Anesthesia / 대한마취과학회지

BACKGROUND: The aim of this study was to evaluate the effect of continuous infusion of ondansetron compared with bolus injection on the incidence of postoperative nausea and vomiting (PONV) in intravenous, patient-controlled analgesia (PCA). METHODS: Sixty three women undergoing laparoscopic-assisted vaginal hysterectomy were randomly allocated according to the method of ondansetron administration: bolus injection of ondansetron (8 mg) after the operation (Bolus group, n = 21); continuous infusion after ondansetron (8 mg) mixed to PCA (PCA 8 mix group, n = 22); and continuous infusion after ondansetron (16 mg) mixed to PCA (PCA 16 mix group, n = 20). The PONV were measured at 1 hr, 6 hr, 24 hr and 48 hr after operation and pain scores (visual analog scale, VAS) were checked. RESULTS: The incidence of PONV during 48 hr in the Bolus group (23.8%) and PCA 16 mix group (20.0%) were significantly lower than PCA 8 mix group (54.5%) (P < 0.05). The three groups showed similar VAS pain scores. CONCLUSIONS: Our results suggest that continuous infusion of ondansetron 16 mg is as effective as a bolus injection of ondansetron (8 mg) at preventing PONV in high-risk patients.

Hyperkalemic cardiac arrest triggered by intravenous lidocaine following axillary brachial plexus block for the creation of an arteriovenous fistula: A case report / 대한마취과학회지

Axillary brachial plexus blockade (BPB) is commonly used as an anesthetic method for patients undergoing the creation of an arteriovenous fistula (AVF) during end-stage renal disease (ESRD). Several studies have shown that the combination of intravenous lidocaine and hyperkalemia in ESRD can produce severe conduction disturbance and asystole. Here, we report a case of cardiac arrest in a 41 year old male patient who manifested severe cardiac conduction disturbance during creation of an AVF. Sixty-five minutes after BPB, the intravenous therapeutic doses of lidocaine administered to treat frequent premature ventricular contractions aggravated his heart rhythm and produced a sine wave and ventricular fibrillation. It was assumed that ventricular fibrillation was induced by a combination of local anesthetics administered during BPB and systemic hyperkalemia as a result of the ESRD [ED highlight-please ensure my changes do not alter your intended meaning]. The patient was completely resuscitated 45 minutes after the cardiopulmonary resuscitation and correction of the hyperkalemia.

Perforation of the superior vena cava during liver transplantation: A case report / 대한마취과학회지

Placement of a pulmonary artery catheter for hemodynamic monitoring in the operating room or intensive care unit is very useful, but this is associated with various complications. They are rupture of the pulmonary artery, pneumothorax, hemothorax, thromboembolism, hemoptysis, arrythmia, valvular damage, sepsis, rupture of the balloon, entrapment or knotting of the catheter and so on. We experienced a case of perforation of the superior vena cava that was caused by a pulmonary artery catheter during liver transplantation. We diagnosed hemothorax during the operation, and we recognized the perforation by performing thoracoscopy. The perforation site was sutured successfully and there were no more problems.