The Diagnostic Accuracy of EXTEM and HEPTEM Clotting Times Versus Standard Laboratory Tests in Cardiac Surgical Patients With and Without Normal FIBTEM Values.

OBJECTIVES: There is extensive evidence to support the use of FIBTEM to identify hypofibrinogenemia during cardiac surgery, but less to support the use of EXTEM and INTEM clotting times (CTs) to identify other plasmatic coagulation factor deficiencies. The aim of the current study was to assess the diagnostic accuracy of EXTEM, INTEM, and HEPTEM CTs, using laboratory international normalized ratio (INR) and activated partial thromboplastin time (aPTT) as reference standards. DESIGN: This was a retrospective diagnostic accuracy study. SETTING: The work took place at a tertiary referral hospital. PARTICIPANTS: A total of 176 cardiac surgical patients were enrolled. INTERVENTIONS: INR, aPTT, ROTEM EXTEM, INTEM, and HEPTEM were measured post-heparin reversal after cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: Sensitivity, specificity, and positive (PPVs) and negative predictive values (NPVs) for EXTEM CT >80 seconds and HEPTEM CT >280 seconds to detect INR ≥2.0, and INTEM CT >205 seconds to detect aPTT ≥38.5 seconds were calculated for all patients and the subset with normal FIBTEM A5 (>6 mm). The prevalence of INR ≥2.0 was 13%. EXTEM CT >80 seconds had a sensitivity of 1.00, specificity of 0.25, PPV of 0.17, and NPV of 1.00. HEPTEM CT >280 seconds had a sensitivity of 0.91, specificity of 0.38, PPV of 0.18, and NPV of 0.97. INTEM CT >205 seconds had a sensitivity of 0.97, specificity of 0.11, PPV of 0.57, and NPV of 0.75 for aPTT ≥38.5 seconds. These values were similar for the subset of patients with normal FIBTEM A5. CONCLUSIONS: EXTEM CT >80 seconds and HEPTEM CT >280 seconds have high sensitivities and NPVs for INR >2.0, which would effectively "rule out" INR >2.0 as a cause for excessive bleeding. However, the low specificities and PPVs indicate they would be less effective in ruling it in. INTEM CT >205 seconds had low PPV and NPV in identifying aPTT >38.5 seconds.

The Use of Extracorporeal Circulation to Facilitate the Resection of a Large Retroperitoneal Sarcoma With Major Vessel Involvement: A Single-Center Review of 20 Cases.

OBJECTIVE: To describe the introduction of extracorporeal corporeal oxygenation (ECMO) to facilitate the surgical resection of large retroperitoneal sarcomas involving major vessels and to report preliminary outcomes. DESIGN: A case series. SETTING: At a tertiary university hospital and state sarcoma center. PARTICIPANTS: Patients undergoing retroperitoneal sarcoma resection requiring inferior vena cava (IVC) reconstruction between June 2018 and March 2022. INTERVENTION: ECMO for retroperitoneal tumor resection requiring IVC reconstruction. MEASUREMENTS AND MAIN RESULTS: A total of 20 patients underwent ECMO-assisted retroperitoneal sarcoma resection and IVC reconstruction. The median age was 60.5 years (IQR 48-69); 15 women and 5 men. The median procedure and ECMO durations were 10.8 hours (IQR 8.5-12.4 hours) and 2.2 hours (IQR 62-218 minutes), respectively. The median intensive care unit and hospital lengths of stay were 4 days (IQR 3-5 days) and 21 days (IQR 14-31 days), respectively. All 20 patients received packed cell transfusions (median 8 per patient [IQR 4-14]); 11 patients required fresh frozen plasma, 6 required platelets, and 11 required fibrinogen supplementation. One patient required recombinant activated factor VII. Sixteen patients experienced acute kidney injury, with 12 patients progressing to chronic kidney disease. Three patients were required to return to the operating room within 7 days, with no returns within the first 24 hours. There was no in-hospital or 30-day mortality. Survival at 3 years was 84%. CONCLUSIONS: ECMO for resecting large retroperitoneal tumor resection was introduced successfully and facilitated satisfactory outcomes for many patients who might otherwise have been considered too high risk.

An audit of the diagnostic accuracy of the ROTEM®sigma for the identification of hypofibrinogenaemia in cardiac surgical patients.

The ROTEM®delta (TEM Innovations GmbH, Munich, Germany) has been used extensively worldwide for the assessment of coagulation in cardiac surgical patients. Recently, a new cartridge-based ROTEM device (ROTEM®sigma, TEM Innovations GmbH, Munich, Germany) has become available. In this paper we report an audit of the diagnostic accuracy of the ROTEM sigma for the identification of hypofibrinogenaemia in cardiac surgical patients. We hypothesised that the diagnostic accuracy of the ROTEMsigma for the identification of hypofibrinogenaemia would be in a similar range to that previously reported for the ROTEMdelta. Simultaneous blood samples for Clauss laboratory fibrinogen and ROTEMsigma FIBTEM measurements were obtained immediately after heparin reversal post-cardiopulmonary bypass in 200 adult cardiac surgical patients. The sensitivity, specificity, and positive and negative predictive values for FIBTEM A5 and A10 for the identification of hypofibrinogenaemia (Clauss fibrinogen <1.5 g/l) were calculated. The prevalence of hypofibrinogenaemia across the 200 patients was 8%. The mean sensitivity and specificity of FIBTEM A10 ≤8 mm for the identification of hypofibrinogenaemia were 0.75 and 0.90 respectively, which are in a similar range to that reported in several previous studies using the ROTEMdelta. For FIBTEM A5 ≤6 mm the values were 0.63 and 0.98 respectively. The predictive values were also in a similar range to those previously reported for the ROTEMdelta, with low false negative rates (2% for A10 ≤8 mm; 3% for A5 ≤6 mm). These findings support the use of the ROTEMsigma as an alternative to the ROTEMdelta for the identification of hypofibrinogenaemia post-cardiopulmonary bypass in cardiac surgical patients. However, further studies are required in other settings.

Euvolemic off pump coronary surgery further improves early postoperative outcomes.

BACKGROUND: Fluid resuscitation during Off-Pump Coronary Surgery (OPCABG) is still not protocolized and depends on multiple variables. We are exploring in this study whether a restrictive or euvolemic approach has any impact on short term surgical outcomes following OPCABG. METHODS: It is a retrospective study of 300 patients analyzed based on the intraoperative fluid requirement with 150 patients in each group (Group I: Fluid <2 Litres, Group II: Fluid >2 Litres). RESULTS: Multivariable analysis showed echocardiography variables such as E/e ratio, LA volume index, and atrial fibrillation (AF). LA volume index is related to the higher fluid requirement. Group II had significantly higher ventilation time (P < 0.05), drain output (P = 0.05), drain removal time (<0.05), inotropic requirement, and diuretic use. CONCLUSION: The requirement of the intraoperative fluid was associated with various factors including diastolic dysfunction (left atrial volume index, left ventricle mass index, E/e ratio) and preoperative dual antiplatelet use. Group II patients had longer ventilation time, diuretics use, high drain output, and required drains for a longer period of time. Although there was no statistical difference among two groups as far as postoperative AF concerned, a reversal of AF to sinus rhythm was delayed in group II patients.

The Influence of Choice of Surgical Procedure on Long-Term Survival After Cardiac Surgery.

BACKGROUND: There is some interest in long-term survival after various cardiac surgical strategies, including off-pump versus on-pump coronary artery surgery (CAG), mitral valve (MV) repair versus replacement, and aortic valve (AV) bioprosthetic versus mechanical replacement. METHODS: We studied patients older than 49 years of age, recording risk factors and surgical details at the time of surgery. We classified procedures as: MV surgery with or without concurrent grafts or valves; AV surgery with or without concurrent CAG; or isolated CAG. Follow-up was through the state death register and state-wide hospital attendance records. Risk-adjusted survival was estimated using Cox proportional hazards. Observed survival was compared to the expected age- and sex- matched population survival. RESULTS: During a median follow-up of 14.8 years 5,807 of 11,718 patients died. The difference between observed and expected survival varied between 3.4 years for AV surgery and 9.6 years for females undergoing MV surgery. The risk-adjusted mortality hazard rate after off-pump CAG was 0.93 (95% CI 0.8-1.0, p=0.84), MV repair 0.67 (95% CI 0.6-0.8, p<0.0001), MV bioprosthesis 0.82 (95% CI 0.81 (0.6-1.0, p=0.11) and bioprosthetic AV replacement 1.02 (95% CI 0.9-1.2, p=0.82). CONCLUSIONS: Compared to the general population, cardiac surgical patients have a shorter than expected life expectancy. We observed a survival benefit of mitral valve repair over replacement. We did not observe significant survival differences between off-pump and on-pump CAG, nor between bioprosthetic and mechanical replacement.

Relationship of perioperative anaphylaxis to neuromuscular blocking agents, obesity, and pholcodine consumption: a case-control study.

BACKGROUND: The observation that patients presenting for bariatric surgery had a high incidence of neuromuscular blocking agent (NMBA) anaphylaxis prompted this restricted case-control study to test the hypothesis that obesity is a risk factor for NMBA anaphylaxis, independent of differences in pholcodine consumption. METHODS: We compared 145 patients diagnosed with intraoperative NMBA anaphylaxis in Western Australia between 2012 and 2020 with 61 patients with cefazolin anaphylaxis with respect to BMI grade, history of pholcodine consumption, sex, age, comorbid disease, and NMBA type and dose. Confounding was assessed by stratification and binomial logistic regression. RESULTS: Obesity (odds ratio [OR]=2.96, χ2=11.7, P=0.001), 'definite' pholcodine consumption (OR=14.0, χ2=2.6, P<0.001), and female sex (OR=2.70, χ2=9.61, P=0.002) were statistically significant risk factors for NMBA anaphylaxis on univariate analysis. The risk of NMBA anaphylaxis increased with BMI grade. Confounding analysis indicated that both obesity and pholcodine consumption remained important risk factors after correction for confounding, but that sex did not. The relative rate of rocuronium anaphylaxis was estimated to be 3.0 times that of vecuronium using controls as an estimate of market share, and the risk of NMBA anaphylaxis in patients presenting for bariatric surgery was 8.8 times the expected rate (74.9 vs 8.5 per 100 000 anaesthetic procedures). CONCLUSIONS: Obesity is a risk factor for NMBA anaphylaxis, the risk increasing with BMI grade. Pholcodine consumption is also a risk factor, and this is consistent with the pholcodine hypothesis. Rocuronium use is associated with an increased risk of anaphylaxis compared with vecuronium in this population.

Diagnostic accuracy of viscoelastic point-of-care identification of hypofibrinogenaemia in cardiac surgical patients: A systematic review.

Hypofibrinogenaemia during cardiac surgery may increase blood loss and bleeding complications. Viscoelastic point-of-care tests provide more rapid diagnosis than laboratory measurement, allowing earlier treatment. However, their diagnostic test accuracy for hypofibrinogenaemia has never been reviewed systematically. We aimed to systematically review their diagnostic test accuracy for the identification of hypofibrinogenaemia during cardiac surgery. Two reviewers assessed relevant articles from seven electronic databases, extracted data from eligible articles and assessed quality. The primary outcomes were sensitivity, specificity and positive and negative predictive values. A total of 576 articles were screened and 81 full texts were assessed, most of which were clinical agreement or outcome studies. Only 10 diagnostic test accuracy studies were identified and only nine were eligible (ROTEMdelta 7; TEG5000 1; TEG6S 1, n = 1820 patients) (ROTEM, TEM International GmbH, Munich, Germany; TEG, Haemonetics, Braintree, MA, USA). None had a low risk of bias. Four ROTEM studies with a fibrinogen threshold less than 1.5-1.6 g/l and FIBTEM threshold A10 less than 7.5-8 mm had point estimates for sensitivity of 0.61-0.88; specificity 0.54-0.94; positive predictive value 0.42-0.70; and negative predictive value 0.74-0.98 (i.e. false positive rate 30%-58%; false negative rate 2%-26%). Two ROTEM studies with higher thresholds for both fibrinogen (<2 g/l) and FIBTEM A10 (<9.5 mm) had similar false positive rates (25%-46%), as did the two TEG studies (15%-48%). This review demonstrates that there have been few diagnostic test accuracy studies of viscoelastic point-of-care identification of hypofibrinogenaemia in cardiac surgical patients. The studies performed so far report false positive rates of up to 58%, but low false negative rates. Further diagnostic test accuracy studies of viscoelastic point-of-care identification of hypofibrinogenaemia are required to guide their better use during cardiac surgery.

Risk stratification using serum lactate in patients undergoing surgical pulmonary embolectomy.

BACKGROUND: Surgical pulmonary embolectomy (SPE) has been around since the early days of cardiac surgery. But with the increase in thrombolytic and intervention options, indications of SPE have been limited. Literature suggests that risk stratification has been a key step in getting good results. We are analyzing serum lactate levels for risk stratification in massive and submassive pulmonary embolism (PE). METHODS: This study is a retrospective analysis of 82 cases that underwent SPE between January 1997 and January 2020. Patients were divided into two groups stratified by venous serum lactate levels on the first admission (Group I: normolactatemia <2 mmol/L, Group II: hyperlactatemia, >2 mmol/L). Primary endpoints were all-cause in-hospital mortality and secondary endpoints were cardiopulmonary bypass time, extracorporeal membrane oxygenator (ECMO) insertion, low cardiac output, blood product use, and right ventricular functions in the follow-up. RESULTS: Our study had an overall follow-up of 23 years with a median of 3.18 years. Overall, the in-hospital mortality rate was 8.54%. Group II had a higher mortality rate (P = .015) and morbidity incidences like cardiopulmonary bypass time (P = .008), ECMO insertion (P = .036), and open chest after surgery (P = .015). Although 5-year survival was better in group I a compared to group II (81%, 95% CI, 69%-93% vs 65%, 95% CI, 46%-84%), the log rank test showed no statistical survival difference among both groups on long-term follow-up. CONCLUSIONS: Long term survival after SPE is good and these results can further be improved by proper PE risk stratification. Alongside computed tomography and echocardiography, the importance of biomarkers like serum lactate can be explored in the PE management algorithm.

Extracorporeal membrane oxygenation-supported percutaneous angioplasty of coronary button stenosis after aortic root replacement.

BACKGROUND AND AIM: A 73-year-old female patient had right coronary button stenosis following aortic root replacement. METHODS: Myocardial ischemia led to hemodynamic instability followed by cardiogenic shock, which was successfully managed using venoarterial extracorporeal membrane oxygenation-supported right coronary button angioplasty. RESULTS AND CONCLUSION: Although the incidence of such complications is low, it is a life-threatening event that requires prompt diagnosis and it may pose a challenging clinical scenario for the treating team.

New antithrombotic agents in the ambulatory setting.

PURPOSE OF REVIEW: Many patients presenting for surgical or other procedures in an ambulatory setting are taking new antiplatelet or anticoagulant agents. This review assesses how the novel features of these new agents affect the management of antithrombotic therapy in the ambulatory setting. RECENT FINDINGS: There have been very few studies investigating the relative risks of continuing or ceasing new antithrombotic agents. Recent reviews indicate that the new antithrombotic agents offer greater efficacy or ease of administration but are more difficult to monitor or reverse. They emphasize the importance of assessing the bleeding risk of the procedure, the thrombotic risk if the agent is ceased, and patient factors that increase the likelihood of bleeding. The timing of cessation of the agent, if required, depends on its pharmacokinetics and patients' bleeding risks. Patients at high risk of thrombotic complications may require bridging therapy. Once agreed upon, the perioperative plan should be made clear to all involved. SUMMARY: As there are few clinical studies to guide management, clinicians must make rational decisions in relation to continuing or ceasing new antithrombotic agents. This requires knowledge of their pharmacokinetics, and a careful multidisciplinary assessment of the relative thrombotic and bleeding risks in individual patients.

Minimally invasive mitral valve surgery using single dose antegrade Custodiol cardioplegia.

OBJECTIVE: Our unit began a minimally invasive mitral surgery (MIMS) program utilising antegrade Custodiol solution as the sole cardioplegia. The aim of this paper is to report our results of this program. PATIENTS/METHODS: Early clinical outcomes were identified and assessed for the first consecutive 100 MIMS patients with comparisons made to a historical group operated via a sternotomy (n=113). The efficacy of myocardial protection was assessed using surrogate outcomes of myocardial protection with serial sodium concentrations also analysed. RESULTS: Six hours postoperatively 12 patients required inotropic support. Peak troponin-I in the first 24 hours was 5.1 (0.8-40 µg/L [median(range)]. Sodium levels decreased following administration of Custodiol but by six hours postoperatively the sodium had returned to greater than 130 mmol/L in all but five patients. Blood transfusion was smaller in the MIMS versus historical group (RBC 17% vs. 65%). MIMS patients had a shorter duration of ventilation, hospital stay and one-year mortality rate (0%). CONCLUSIONS: In this series of patients undergoing MIMS, single dose antegrade Custodiol offers satisfactory and safe myocardial protection. Early clinical outcomes were also satisfactory. Whilst our findings are observational, they nevertheless support the use of this less invasive approach to mitral surgery using single dose Custodiol for myocardial protection.

CT pulmonary angiography during veno-arterial extracorporeal membrane oxygenation in an adult.

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) causes changes in the filling and blood flow of the cardiac chambers and pulmonary vessels as well as alterations in the path of intravenous contrast injected during CT. We present a patient with a potentially misleading CT pulmonary angiogram while on full VA ECMO. We demonstrate circulatory changes as well as alterations in contrast flow when ECMO flows are reduced.

Management of coagulation: an Australian perspective.

PURPOSE OF REVIEW: New anticoagulants and new techniques bring challenges and opportunities to the practice of anaesthesia. Existing guidelines may not be up-to-date with these changes, so this review will examine the current research with a view to identifying deficiencies in existing guidelines, particularly those that may guide Australian anaesthetists. RECENT FINDINGS: The novel oral anticoagulants dabigatran and rivaroxaban, and the potent antiplatelet agents ticagrelor and prasugrel are available in Australia. Considerable research data support the benefit of using these drugs, but the risk profile is incompletely understood. The concept of damage control resuscitation is supported by plentiful, but potentially flawed, observational data, and also the technique may be associated with adverse effects. It remains difficult to firmly quantify the risks of using tranexamic acid or recombinant factor 7a in many clinical situations. SUMMARY: Despite much interesting recent research, few current guidelines are likely to require modification. Novel pharmaceuticals have risk profiles that are incompletely understood, but will only become evident on phase-4 testing. Australasian guidelines for reversal of warfarin may need to be updated to include advice on the use of recombinant factor 7a.

Patient perceptions of regional anesthesia: influence of gender, recent anesthesia experience, and perioperative concerns.

BACKGROUND AND OBJECTIVES: Anesthesiologists often find that patients would prefer a general anesthetic (GA) to a regional anesthetic (RA) for surgery. We surveyed patients' attitudes to RA in an Australian tertiary-care hospital, hoping to understand the reasons for acceptance or refusal. We explored how 3 main factors influence the patient's choice for subsequent RA: gender, type of anesthetic on the day of surgery, and perioperative concerns. METHODS: Consecutive patients at a single institution were interviewed on the first postoperative day by a research nurse, either as a face-to-face interview or by telephone after ambulatory surgery. A short description of RA and GA was given, and preferences for future anesthesia and concerns were recorded. RESULTS: Complete data were obtained from 1000 patients. More women preferred GA compared with men (76.3% vs 69.0%). Patients who received only RA during their surgery on the previous day were almost 3 times more likely to express a future preference for RA compared with those who received any GA, using hypothetical examples of arm or hip surgery (83.2% vs 21.1%, P = 0.00001). Patients expressed more concerns about hearing or seeing the surgery than experiencing a complication, and 84% preferred sedation. CONCLUSIONS: More patients, especially females, may accept RA if reassured appropriately about not hearing or seeing the surgery. Once patients have experienced RA, they are more likely to choose it in future. Modification of our discussion and consent process may increase the uptake of RA techniques.