Use of laboratory testing for prediction of postoperative bleeding volume in cardiovascular surgery.

BACKGROUND: Coagulopathy and following massive bleeding are complications of cardiovascular surgery, particularly occurring after procedures requiring prolonged cardiopulmonary bypass (CPB). Reliable and rapid tests for coagulopathy are desirable for guiding transfusion. Measuring multiple coagulation parameters may prove useful. The purpose of this study is to determine the laboratory parameters predicting massive bleeding. METHODS: In a prospectively collected cohort of 48 patients undergoing cardiovascular surgery, markers of coagulation and fibrinolysis were measured using automated analyzer and their correlations with bleeding volume were determined. RESULTS: Operation time was 318 (107-654) min. CPB time was 181 (58-501) min. Bleeding volume during surgery was 2269 (174-10,607) ml. Number of transfusion units during surgery were packed red blood cells 12 (0-30) units, fresh frozen plasma 12 (0-44) units, platelets 20 (0-60) units and intraoperative autologous blood collection 669 (0-4439) ml. Post-surgery activities of coagulation factors II (FII), FV, FVII, FVIII, FIX, FX, FXI and FXII were decreased. Values of fibrinogen, antithrombin, α2 plasmin inhibitor (α2PI) and FXIII were also decreased. Values of thrombin-antithrombin complex (TAT) were increased. Values of FII, FIX, FXI and α2PI before surgery were negatively correlated with bleeding volume (FII, r = - 0.506: FIX, r = - 0.504: FXI, r = - 0.580; α2PI, r = - 0.418). Level of FIX after surgery was negatively correlated with bleeding volume (r = - 0.445) and level of TAT after surgery was positively correlated with bleeding volume (r = 0.443). CONCLUSIONS: These results suggest that several clinical and routine laboratory parameters of coagulation were individually associated with bleeding volume during cardiovascular surgery. Determining the patterns of coagulopathy may potentially help guide transfusion during cardiovascular surgery.

Effectiveness and Safety of Ultrasound Guided Lower Extremity Nerve Blockade in Infragenicular Bypass Grafting for High Risk Patients With Chronic Limb Threatening Ischaemia.

OBJECTIVES: Surgical revascularisation to accomplish limb salvage remains preferable in some patients with chronic limb threatening ischaemia (CLTI). The aim of this study was to evaluate the effectiveness and safety of ultrasound guided lower extremity nerve blockade (UGNB) in infragenicular bypass surgery (IGBS). METHODS: This was a single centre, retrospective clinical study. Fifty-nine patients with CLTI (67 limbs) who underwent IGBS under UGNB (femoral and sciatic nerve blockade) at Asahikawa Medical University between January 2012 and December 2017 were compared with patients with CLTI (137 limbs) who underwent IGBS under general anaesthesia (GA) over the same period. Propensity score matching based on pre-operative comorbidities was used to minimise background differences of the two groups. RESULTS: Fifty-six pairs of CLTIs were matched and analysed (55% dialysis dependent). Procedure duration was similar between the two groups, but intraoperative catecholamine index and intravenous fluid volume were lower with UGNB compared with GA (2.9 ± 4.6 vs. 5.9 ± 6.5; p < .01 and 1831 ± 990 vs. 2335 ± 931 mL; p < .01, respectively). The mean arterial blood pressure during induction of anaesthesia was significantly decreased with GA. Post-operatively, the time period to resume a clear liquid and solid food diet was significantly shorter with UGNB (P<0.01 for both outcome measures). Intravenous fluid volume was significanlty lower, while cardiac complications and delirium, based on the NEECHAM confusion scale, occurred significantly less often with UGNB than GA. These significant differences show advantages of UGNB compared to GA. No mortality or major amputations were observed in either group. Early graft thrombosis was observed in five limbs (8.9%) with UGNB and in four limbs with GA (7.1%) (p = .73). CONCLUSIONS: UGNB has advantages for intra- and post-operative management and could be a useful method to prevent peri-operative complications for high risk patients with CLTI. To ensure the effectiveness of UGNB for IGBS for future indications, a randomised study is required.

Reliability of Cardiac Output Measurements Using LiDCOrapid and Calibration by Transesophageal Echocardiography With the Continuous Pulmonary Artery Thermodilution Method in Patients Undergoing Aortic Valve Replacement for Aortic Stenosis.

OBJECTIVE: This study investigated the accuracy of arterial waveform analysis estimations of cardiac output (COAW) and the efficacy of calibrations involving transesophageal echocardiography with continuous cardiac output values obtained using a pulmonary artery catheter. DESIGN: Prospective cohort study. SETTING: University hospital operating room. PARTICIPANTS: Twelve patients undergoing aortic valve replacement for aortic stenosis. INTERVENTIONS: A pulmonary artery catheter was placed in each patient, and continuous cardiac output was determined using thermodilution principles. LiDCOrapid and transesophageal echocardiography were used to measure COAW and to perform the calibration, respectively. MEASUREMENTS AND MAIN RESULTS: Simultaneous recording of continuous cardiac output and COAW values were performed every 20 minutes, after inducing anesthesia. COAW was calibrated using transesophageal echocardiography (COAW-cal) before and after initiating cardiopulmonary bypass (CPB); the COAW and COAW-cal were recorded concurrently using a LiDCOrapid monitor. For the pre-CPB dataset (34 data pairs), the mean bias and percentage error were, respectively, 0.10 L/min and 34% for COAW versus continuous cardiac output and -0.098 L/min and 27% for COAW-cal versus continuous cardiac output. Similarly, for the post-CPB (45 data pairs), the mean bias and percentage error were, respectively, 0.75 L/min and 34% for COAW and 0.059 L/min and 26% for COAW-cal. A 4-quadrant plot demonstrated an acceptable pre-CPB concordance rate of 93.3% for COAW and 93.8% for COAW-cal. CONCLUSION: COAW measurements, using LiDCOrapid, have acceptable trending ability pre-CPB. The determination of cardiac output variations, using transesophageal echocardiography, is useful for managing patients undergoing aortic valve replacement for aortic stenosis.

Morphologic Evaluation of the Mitral Annulus During Displacement of the Heart in Off-Pump Coronary Artery Bypass Surgery.

OBJECTIVE: To evaluate the morphologic changes of the mitral annulus using 3-dimensional transesophageal echocardiography during heart displacement to expose the anastomosis site in off-pump coronary artery bypass surgery (OPCAB). DESIGN: Prospective case series. SETTING: Single center, university hospital. PARTICIPANTS: The study comprised 34 consecutive patients who underwent OPCAB of the left circumflex artery (LCX) and the right coronary artery (RCA). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Mitral annulus parameters were measured using the Mitral Valve Quantification program after sternotomy (physiologic position) and during displacement of the heart to expose the LCX (LCX position) and the RCA (RCA position). The height of the mitral annulus was significantly lower in the LCX (5.76 ± 0.90 mm) and RCA (5.92 ± 0.97 mm) positions than in the physiologic position (6.96 ± 0.99 mm; both p < 0.0001). The percent change in the height of the mitral annulus was significantly greater in the mitral regurgitation group than in the mitral regurgitation nondeterioration group when in the LCX (-16.3% ± 6.0% v -11.9% ± 3.3%, p = 0.0203) and RCA (-16.9% ± 6.3% v -12.1% ± 3.8%, p = 0.0207) positions. The anteroposterior and intercommissural diameters, annulus perimeter, and surface area of the mitral annulus did not differ significantly among all heart positions. CONCLUSIONS: The mitral annulus flattened and lost its saddle shape without expanding while in the LCX and RCA positions. The greater percent change in the height of the mitral annulus may aggravate mitral regurgitation.

Duration of the action of rocuronium in patients with BMI of less than 25: An observational study.

BACKGROUND: The duration of rocuronium in patients with BMI more than 30 kg m is prolonged. Whether the reverse is true when BMI is less than 18.5 kg m is unclear. OBJECTIVE: The objective of this study was to investigate whether a BMI less than 25 kg m affects the duration of rocuronium in doses adjusted for actual body weight. DESIGN: A prospective, observational, single-centre study. SETTING: The operating room of a teaching hospital from 1 June 2008 to 30 June 2015. PATIENTS: Thirty patients with American Society of Anesthesiologists physical status I or II who were scheduled to undergo elective surgery (BMI < 25 kg m, aged 23 to 74 years) maintained by 0.7 minimum alveolar concentration sevoflurane and remifentanil. MAIN OUTCOME MEASURES: Repetitive train-of-four stimulation was applied and contractions of the adductor pollicis muscle were recorded. Duration of the initial dose of rocuronium (D1) was defined as the time from injection of rocuronium 0.6 mg kg to return of first twitch height to 25% of the control. Duration of additional doses (D2) was the time from a supplement of 0.15 mg kg rocuronium to return of first twitch height to 25% of the control. The relationship between D1 or D2 and BMI was examined using linear regression analysis. RESULTS: Linear regression analysis revealed a significant correlation between duration of initial dose and BMI (R = 0.246; P = 0.00531). A significant correlation between the duration of the additional dose and BMI was also found (R = 0.316; P = 0.00122). CONCLUSION: The lower the BMI, the shorter the duration of rocuronium at initial and additional doses determined by the actual body weight in adult patients with a BMI less than 25 kg m. TRIAL REGISTRATION: www.umin.ac.jp/ctr/index/htm with registry number UMIN 00009337 and UMIN 000015407.

Ultrasound-guided lumbar plexus block using three different techniques: a comparison of ultrasound image quality.

PURPOSE: The purpose of this study was to compare the ultrasound image quality at three different transducer positions for ultrasound-guided lumbar plexus block (LPB). METHODS: This prospective comparative study included 30 patients who underwent total hip arthroplasty under general anesthesia in combination with LPB. Using the same ultrasound machine settings for each patient, a transverse view of the lumbar plexus (LP) at the L3-4 vertebral level was obtained with a convex transducer placed at three different positions: immediately lateral to the dorsal midline (medial position), almost 5 cm lateral to the dorsal midline (paravertebral position), and at the abdominal transverse flank (shamrock position). Ultrasound-guided LPB with catheter insertion was performed via in-plane needle insertion with the transducer randomly assigned to one of the three positions. The echo intensity (EI) ratio of the LP to psoas major muscle (PMM), the EI of the LP and PMM, and the ultrasound visibility score of the needle, local anesthetic, and catheter were recorded. RESULTS: The LP/PMM EI ratio was significantly higher at paravertebral position (1.4 ± 0.2) than at medial position (1.2 ± 0.2; p = 0.003) and shamrock position (1.3 ± 0.2; p = 0.040). The EI of the LP and PMM was highest at shamrock position (p < 0.001). During the block procedure, the ultrasound visibility score of the needle and local anesthetic was significantly higher at paravertebral position than at medial position. CONCLUSION: Under the conditions of this study, the contrast between LP and PMM is significantly higher at paravertebral position than at medial position and at the abdominal transverse flank (shamrock position). LP and PMM at the shamrock position appear significantly brighter among the three probe positions in sonograms.

Preparing for the unexpected: special considerations and complications after sugammadex administration.

Sugammadex, a modified gamma-cyclodextrin, has changed clinical practice of neuromuscular reversal dramatically. With the introduction of this selective relaxant binding agent, rapid and reliable neuromuscular reversal from any depth of block became possible. Sugammadex can reverse neuromuscular blockade without the muscarinic side effects typically associated with the administration of acetylcholinesterase inhibitors. However, what remained unchanged is the incidence of residual neuromuscular blockade. It is known that sugammadex cannot always prevent its occurrence, if appropriate dosing is not chosen based on the level of neuromuscular paralysis prior to administration determined by objective neuromuscular monitoring. Alternatively, excessive doses of sugammadex administered in an attempt to ensure full and sustained reversal may affect the effectiveness of rocuronium in case of immediate reoperation or reintubation. In such emergent scenarios that require onset of rapid and reliable neuromuscular blockade, the summary of product characteristics (package insert) recommends using benzylisoquinolinium neuromuscular blocking agents or a depolarizing agent. However, if rapid intubation is required, succinylcholine has a significant number of side effects, and benzylisoquinolinium agents may not have the rapid onset required. Therefore, prior administration of sugammadex introduces a new set of potential problems that require new solutions. This novel reversal agent thus presents new challenges and anesthesiologists must familiarize themselves with specific issues with its use (e.g., bleeding risk, hypermagnesemia, hypothermia). This review will address sugammadex administration in such special clinical situations.

Perioperative Management of Patients With End-Stage Renal Disease.

End-stage renal disease (ESRD) is associated with significant alterations in cardiovascular function; homeostasis of body fluid, electrolytes, and acid-base equilibrium; bone metabolism, erythropoiesis; and blood coagulation. The prevalence of ESRD is increasing rapidly worldwide, as is the number of patients requiring surgery under general anesthesia. Patients with ESRD have significantly higher risks of perioperative morbidity and mortality due to multiple comorbidities. The perioperative management of patients with ESRD under general anesthesia therefore requires special considerations and a careful multidisciplinary approach. In this review, the authors summarize the available literature to address common issues related to patients with ESRD and discuss the best perioperative approach for this patient subgroup.

Comparison of caudal ropivacaine-morphine and paravertebral catheter for major upper abdominal surgery in infants.

BACKGROUND: The caudal epidural block is one of the most commonly used regional anesthetic techniques in children. Administration of morphine via caudal injection enables analgesia, even for upper abdominal surgery. The thoracic paravertebral block has also been successfully used to treat perioperative pain during upper abdominal procedures in pediatric patients. AIM: In the current study, we compared the two regional techniques for upper abdominal surgery in infants to determine whether one of them was preferable to the other. METHODS: Consecutive patients under 12 months of age who underwent upper abdominal surgery were retrospectively divided according to the chosen postoperative analgesia: Group C, caudal ropivacaine-morphine; Group P, paravertebral catheter. We analyzed the following outcomes: requirement for additional analgesics, pain scores, need for mechanical ventilation and oxygen dosage, postoperative blood pressure and heart rate, time to pass first stool, time until first full meal, and complications. RESULTS: Twenty-one consecutive patients were included: 10 in Group C and 11 in Group P. Median age at surgery was 80 (47.5-270.0) and 84.5 (34.3-287.5) days, respectively. No difference was found between the two groups in requirement for additional analgesics at 24 h after surgery (median 1 in Group C vs 1 in Group P, P = 0.288, 95% CI: -2 to 1). BOPS pain scores were only lower in Group P when compared to Group C at 24 h after surgery (median 1 vs 2, P = 0.041, 95% CI: -2 to 0). None of the patients had perioperative complications. CONCLUSIONS: In this small series, there was no significant difference between caudal ropivacaine-morphine and paravertebral catheter for postoperative care in infants undergoing upper abdominal surgery. Further prospective studies are needed to compare the efficacy and incidence of complications of caudal block and paravertebral catheter for postoperative analgesia.

[The Efficacy of Ultrasound-guided Radial Artery Catheterization.]

BACKGROUND: The goal of this study was to evaluate in patients with peripheral arterial disease (PAD) whether ultrasound-guided radial artery catheterization decreased procedural time and number of attempts compared with the traditional palpation technique. METHODS: Ultrasonography was evaluated for arte- rial catheterization after the traditional palpation tech- nique was unsuccessful in 480 seconds in 10 patients with PAD. The vascular access was performed by a single anesthesiologist. The successful catheterization time and the number of attempts were recorded. We also measured the diameter of the radial artery, the skin-to-artery distance, and the distance between the linear probe and puncture site. RESULTS: The mean overall time per patient for catheter insertion was 220.0?112.6 sec in the ultra- sound group vs. 480 sec in the palpation group (P= 0.0029). The mean number of attempts was 1.30?0.48 in the ultrasound group vs. 4.50?0.53 in the palpation group (P = 0.0024). All catheterizations were success- ful, and no failure was encountered in the ultrasound group. CONCLUSIONS: Ultrasound-guided radial artery cath- eterization took less time to establish the arterial line, and it reduced the number of attempts when com- pared with the palpation technique.

[Evaluation of the Effects of Remifentanil Doses on Hemodynamics and Perfusion Index at the Onset of Pneumoperitoneum during Laparoscopic Surgery].

BACKGROUND: The aim of this study was to investigate whether changes in perfusion index (PI) correlate with non-invasive haemodynamic parameters (HR, BP) following the onset of pneumoperitoneum under two doses (moderate-dose (MD) and high-dose (HD)) of remifentanil and to compare its reliability. METHODS: We divided 33 patients who were scheduled for laparoscopic surgery under general anesthesia into two groups according to the dose of continuously infused remifentanil: moderate dose 0.5 µg x kg(-1) x min(1) (MD group, n = 16) and high dose 1.0 µg x kg(-1) x min(-1) (HD group, n = 17). Non-invasive blood pressure (NIBP), HR, and PI were measured before the start of surgery (time 1), after the start of surgery (time 2), before the start of pneumoperitoneum (time 3), and 1 min after the stable state of pneumoperitoneum (time 4). RESULTS: PI decreased from the baseline after pneumoperitoneum in MD group, on the other hand PI did not change in HD group. Between the two groups, the magnitude of the PI changes was statistically different although MBP and HR were not statistically different CONCLUSIONS: PI may be a reliable and easier alternative to conventional haemodynamic parameters for detection of stress response to pneumoperitoneum during remifentanil anaesthesia in adult patients.

Target-controlled infusion and population pharmacokinetics of landiolol hydrochloride in gynecologic patients.

PURPOSE: We previously determined the pharmacokinetic (PK) parameters of landiolol in healthy male volunteers. In this study, we evaluated the usefulness of target-controlled infusion (TCI) of landiolol hydrochloride and determined PK parameters of landiolol in gynecologic patients. METHODS: Nine patients who were scheduled to undergo gynecologic surgery were enrolled. After inducing anesthesia, landiolol hydrochloride was administered at the target plasma concentrations of 500 and 1,000 ng/mL for each 30 min. A total of 126 data points of plasma concentration were collected from the patients and used for the population PK analysis. Furthermore, a population PK model was developed using the nonlinear mixed-effect modeling software. RESULTS: The patients had markedly decreased heart rates (HRs) at 2 min after the initiation of landiolol hydrochloride administration; however, their blood pressures did not markedly change from the baseline value. The concentration time course of landiolol was best described by a 2-compartment model with lag time. The estimate of PK parameters were total body clearance (CL) 34.0 mL/min/kg, distribution volume of the central compartment (V 1) 74.9 mL/kg, inter-compartmental clearance (Q) 70.9 mL/min/kg, distribution volume of the peripheral compartment (V 2) 38.9 mL/kg, and lag time (ALAG) 0.634 min. The predictive performance of this model was better than that of the previous model. CONCLUSION: TCI of landiolol hydrochloride is useful for controlling HR, and the PK parameters of landiolol in gynecologic patients were similar to those in healthy male volunteers and best described by a 2-compartment model with lag time.

[Efficacy of Ultrasound-guided Thoracic Paravertebral Block Compared with the Epidural Analgesia in Patients Undergoing Video-assisted Thoracoscopic Surgery].

BACKGROUND: Thoracic paravertebral block (TPVB) has proven to be safer by using ultrasound imaging. This prospective randomized study was designed to investigate postoperative pain relief and intraoperative hemodynamics in patients undergoing ultrasound-guided TPVB or epidural analgesia. METHODS: Twelve patients scheduled for thoracoscopic surgery for lung cancer were randomly divided into two groups and received ultrasound guided TPVB (N=6) or epidural analgesia (N=6). Both groups received postoperative analgesia with continuous infusion of 0.2% ropivacaine 6 ml · hr(-1) via paravertebral or epidural block. Postoperative numeric rating score (NRS) and the data of intraoperative hemodynamics were collected. RESULTS: In comparison with the epidural group, the level of NRS was higher in the TPVB group at 12 hr (4.5±1.05 vs 2.7±0.82, P<0.01), and 24 hr (4.5±1.05 vs 2.7±0.82, P<0.01) after surgery. In the TPVB group, the intraoperative amount of transfusion was smaller (1,331±147 ml vs 1,693±162 ml, P<0.01) and the lowest systolic pressure was higher (87±4.56 mmHg vs 73±4.34 mmHg, P<0.01) than that of the epidural group. CONCLUSIONS: Ultrasound guided TPVB was performed affecting hemodynamics less than the epidural anesthetic. There was less postoperative analgesic effect on TPBV than on epidural analgesia after thora- coscopic surgery when continuously infusing 0.2% ropivacaine 6 ml · hr(-1).

A temporary decrease in twitch response following reversal of rocuronium-induced neuromuscular block with a small dose of sugammadex in a pediatric patient.

We report a temporary decrease in twitch response following reversal of rocuronium-induced neuromuscular block with a small dose of sugammadex in our dose-finding study in pediatric patients. A 19-month-old female infant (9.6 kg, 80 cm) was scheduled for elective cheiloplasty surgery. Anesthesia was induced with nitrous oxide 50% and sevoflurane 5% and maintained with air, oxygen, sevoflurane 3%, and fentanyl (total, 3 µg/kg). Neuromuscular monitoring was performed at the adductor pollicis muscle after induction of anesthesia but before the administration of rocuronium. Total dose of rocuronium during the surgery was 0.9 mg/kg. Neuromuscular block was reversed with 0.5 mg/kg sugammadex when one response was observed with post-tetanic count stimulation. Twitch responses after sugammadex administration showed a temporary decrease after its initial recovery. Maximum decreases in twitch responses were observed 17 min after initial dose of sugammadex. Twitch responses recovered to their control values after additional doses of 3.5 mg/kg sugammadex (4 mg/kg in total). Time from sugammadex administration to maximum decreases in twitch responses is earlier than has been reported in adults (20-70 min). It is demonstrated that following neuromuscular block reversal with insufficient dose of sugammadex, there is a possibility of the recurrence of residual paralysis within less than 20 min in pediatric patients.

Preoperative morphological analysis by transesophageal echocardiography and predictive value of plasma landiolol concentration during systolic anterior motion mitral valve repair : a report of three cases.

We report three cases with systolic anterior motion (SAM) after mitral valve plasty. Preoperative mitral valve morphology is a risk factor for SAM. The morphological characteristics of SAM have been revealed in several studies. We found a small distance between coaptation and the interventricular septum in all cases, and cases 2, and 3 had a low AL/PL ratio, whereas case 3 had a large PML, which was revealed by transesophageal echocardiography. With the use of 3D transesophageal echocardiography, when mitral valve prolapse was investigated, in all three cases, it was easy to specify lesions. The issue for the future is 3D analysis when SAM is occurring.

[Case report of cardiac arrest during carotid body tumor resection].

We report a case of 30-second cardiac arrest that occurred during carotid body tumor resection due to the carotid sinus reflex. The patient was a 20-year-old man diagnosed with a carotid body tumor and scheduled for tumor resection. General anesthesia was induced and maintained with target controlled infusion of propofol. Analgesia was achieved with continuous administration of remifentanil. When the surgery was initiated, 1% lidocaine 3 ml was locally injected into the carotid bifurcation. When surgery was initiated in the neck region, the patient developed sudden cardiac arrest. Chest compression was immediately initiated, and atropine 0.5 mg was administered; subsequently circulation was restored. Surgery was resumed after placing a temporary pacemaker through the left subclavian vein. The surgery was successfully performed without any other bradycardia complications, and the patient recovered from general anesthesia without sequelae. Thus, the findings indicate the importance of considering the pacemaker placement before carotid body tumor resection.