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.

Correction to: Hypothermic circulatory arrest induced coagulopathy: rotational thromboelastometry analysis.

The article "Hypothermic circulatory arrest induced coagulopathy: rotational thromboelastometry analysis", written by Hayato Ise, Hiroto Kitahara, Kyohei Oyama, Keiya Takahashi, Hirotsugu Kanda, Satoshi Fujii, Takayuki Kunisawa, Hiroyuki Kamiya, was originally published electronically on the publisher's internet portal on 7 June 2020 without open access.

Hypothermic circulatory arrest induced coagulopathy: rotational thromboelastometry analysis.

OBJECTIVES: Hypothermic circulatory arrest (HCA) has been considered to cause coagulopathy during cardiac surgery. However, coagulopathy associated with HCA has not been understood clearly in details. The objective of this study is to analyze the details of coagulopathy related to HCA in cardiac surgery by using rotational thromboelastometry (ROTEM). METHODS: We retrospectively analyzed 38 patients who underwent elective cardiac surgery (HCA group = 12, non-HCA group = 26) in our hospital. Blood samples were collected before and after cardiopulmonary bypass (CPB). Standard laboratory tests (SLTs) and ROTEM were performed. We performed four ROTEM assays (EXTEM, INTEM, HEPTEM and FIBTEM) and analyzed the following ROTEM parameters: clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF) and maximum clot elasticity (MCE). The amount of perioperative bleeding, intraoperative transfusion and perioperative data were compared between the HCA and non-HCA group. RESULTS: Operation time and hemostatic time were significantly longer in the HCA group, whereas CPB time had no difference between the groups. The amount of perioperative bleeding and intraoperative transfusion were much higher in the HCA group. SLTs showed no difference between the groups both after anesthesia induction and after protamine reversal. In ROTEM analysis, MCE contributed by platelet was reduced in the HCA group, whereas MCE contributed by fibrinogen had no difference. CONCLUSION: Our study confirmed that the amount of perioperative bleeding and intraoperative transfusion were significantly higher in the HCA group. ROTEM analysis would indicate that clot firmness contributed by platelet component is reduced by HCA in cardiac 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.

Transfer of a minimally invasive mitral valve repair program from a high-volume center to a very low volume center: how many cases are necessary to maintain acceptable results?

OBJECTIVE: To investigate whether minimally invasive mitral valve repair (MIMVR) can be transferred from a high-volume center into a very small volume center and to clarify how many cases are necessary for maintenance of this program, early outcomes of MIMVR in Asahikawa Medical University were compared with those results in patients operated by a single surgeon in Duesseldorf University Hospital. METHODS: Sixty-five patients who underwent MIMVR in Asahikawa Medical University (group A) between May 2014 and July 2018 and 134 patients who underwent MIMVR in Duesseldorf University Hospital (group D) between September 2009 and January 2014 by a surgeon who started MIMVS later in Asahikawa were retrospectively analyzed. RESULTS: In group D, there were more patients with ischemic mitral valve regurgitation and with annular calcification than in group A. Survival rate at 6 months and 1 year was 98.5% and 98.5% in group A and 92.9% and 91.3% in group D, respectively. EuroSCORE II was significantly higher in patients dead within 30 days and within the first year. CONCLUSIONS: The present study demonstrated that MIMVR programs can be transferred with acceptable early results into very low volume centers, if the team is developed by surgeons who are well trained and experienced in MIMVR. Moreover, the present study suggested that case number for maintenance of acceptable results may be obviously less than the previous recognition that this kind of specialized surgery could be maintained with at least 50 cases annually. However, meticulous preparations for surgery are essential for satisfactory surgical outcomes.

Cerebral Circulation During Retrograde Cerebral Perfusion: Evaluation Using Laser Speckle Flowgraphy.

BACKGROUND: The cerebroprotective effect of retrograde cerebral perfusion (RCP) and selective antegrade cerebral perfusion (SCP) still remains controversial. Laser speckle flowgraphy has shown much promise for novel perioperative neuromonitoring by assessing blood flow of the optic nerve head. This study aimed to evaluate the cerebral microcirculation in humans using laser speckle flowgraphy during simple circulatory arrest, RCP, and SCP under moderate hypothermia and to investigate whether RCP under moderate hypothermia is a reliable method of cerebral protection. METHODS: A total of 23 consecutive patients who underwent a scheduled aortic arch or hemiarch surgical procedure on thoracic aorta aneurysm were enrolled. The laser speckle flowgraphy measurement that calculates mean blur ratio, a parameter of cerebral circulation, was obtained 6 times: after induction of anesthesia, baseline (T1), after initiation of cardiopulmonary bypass with cardiac arrest (T2), simple circulatory arrest (T3), RCP (T4), SCP (T5), and after the termination of cardiopulmonary bypass (T6). RESULTS: Both mean blur ratios of simple circulatory arrest and RCP were significantly decreased compared with baseline. In contrast, no significant differences were observed between simple circulatory arrest and RCP. The mean blur ratio of SCP was significantly increased compared with both simple circulatory arrest and RCP. CONCLUSIONS: In conclusion, no significant difference was observed in the cerebral circulation between RCP and simple circulatory arrest without adjunctive strategy under moderate hypothermia. In contrast, the cerebral circulation during SCP was significantly higher than simple circulatory arrest and RCP. These results suggest that cerebral microcirculation may not be adequate during RCP compared with SCP under moderate hypothermia.

Minimally Invasive Awake Mitral Valve Surgery and Cardiopulmonary Bypass Without General Anesthesia.

Herein, we report the case of a 49-year-old man with a potentially fatal allergy to propofol and remifentanil who underwent awake minimally invasive mitral valve surgery with cardiopulmonary bypass using thoracic epidural anesthesia, without the need for endotracheal general anesthesia. The aim was the management of spontaneous respiration during cardiopulmonary bypass surgery in an awake patient.

Desflurane for management of decompressive laminectomy in a patient with hereditary spastic paraplegia: a case report.

BACKGROUND: Hereditary spastic paraplegia (HSP) is a rare, genetic neurodegenerative condition. Thus far, ideal anesthetic management is not established for patients with HSP; therefore, careful selection and dosage of anesthetic agents is required. CASE PRESENTATION: A 54-year-old woman with HSP, who was diagnosed with severe lumbar spinal canal stenosis, underwent decompressive laminectomy to relieve her back pain. Preoperatively, she experienced slight difficulty in walking independently; however, she exhibited no other dysfunction. Anesthesia was maintained with desflurane after tracheal intubation. Rocuronium and sugammadex were used for neuromuscular blockade and reversal, respectively, with neuromuscular monitoring equipment. The patient showed uneventful postoperative recovery without signs of neurological deterioration after extubation. CONCLUSIONS: Our successful experience in this case implies that, for patients with neuromuscular diseases, including HSP, desflurane may be an option for anesthetic management; moreover, careful assessment (e.g., medical condition, bispectral index, and train-of-four) should be performed prior to administration of anesthesia.

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.

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.

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.