Factors associated with vasoplegic shock in the postoperative period of cardiac surgery and influence on morbidity and mortality of the use of arginine vasopressin as rescue therapy

OBJECTIVES

Analyzing associated factors with vasoplegic shock in the postoperative period of Cardiac Surgery. Analyzing the influence of vasopressin as rescue therapy to first-line treatment with norepinephrine.

DESIGN

Cohort, prospective and observational study.

SETTING

Main hospital Postoperative Cardiac ICU.

PATIENTS

Patients undergoing cardiac surgery with subsequent ICU admission from January 2021 to December 2022.

INTERVENTIONS

Record of presurgical, perioperative and ICU discharge clinical variables.

MAIN VARIABLES OF INTEREST

chronic treatment, presence of vasoplegic shock, need for vasopressin, cardiopulmonary bypass time, mortality.

RESULTS

773 patients met the inclusion criteria. The average age was 67.3, with predominance of males (65.7%). Post-CPB vasoplegia was documented in 94 patients (12.2%). In multivariate analysis, vasoplegia was associated with age, female sex, presurgical creatinine levels, cardiopulmonary bypass time, lactate level upon admission to the ICU, and need for prothrombin complex transfusion. Of the patients who developed vasoplegia, 18 (19%) required rescue vasopressin, associated with pre-surgical intake of ACEIs/ARBs, worse Euroscore score and longer cardiopulmonary bypass time. Refractory vasoplegia with vasopressin requirement was associated with increased morbidity and mortality.

CONCLUSIONS

Postcardiopulmonary bypass vasoplegia is associated with increased mortality and morbidity. Shortening cardiopulmonary bypass times and minimizing products blood transfusion could reduce its development. Removing ACEIs and ARBs prior to surgery could reduce the incidence of refractory vasoplegia requiring rescue with vasopressin. The first-line treatment is norepinephrine and rescue treatment with VSP is a good choice in refractory situations. The first-line treatment of this syndrome is norepinephrine, although rescue with vasopressin is a good complement in refractory situations.

Comparison of Clinical Scoring Tools to Predict Heparin-Induced Thrombocytopenia in Cardiac Surgery

The 4Ts and HIT-Expert Probability (HEP) scoring tools for heparin-induced thrombocytopenia (HIT) have not been validated in cardiac surgery patients, and the reported sensitivity and specificity of the Post-Cardiopulmonary Bypass (CPB) scoring tool vary widely in the 2 available analyses. It remains unclear which of the available scoring tools most accurately predicts HIT in this population. Forty-nine HIT-positive patients who underwent on-pump cardiac surgery within a 6-year period were loosely matched to 98 HIT-negative patients in a 1:2 case-control design. The 4Ts, HEP, and CPB scores were calculated for each patient. Sensitivity and specificity of each tool were calculated using standard cut-offs. The Youden method was utilized to determine optimal cut-offs within receiver operating characteristic (ROC) curves of each score, after which sensitivities and specificities were recalculated. Using standard cut-offs, the sensitivities for the CPB, HEP, and 4Ts scores were 100%, 93.9%, and 69.4%, respectively. Specificities were 51%, 49%, and 71.4%, respectively. The AUC of the scoring tool ROC curves were 0.961 for the CPB score, 0.773 for the HEP score, and 0.805 for the 4Ts score. Using the Youden method-derived optimal cut-off of  ≥3 points on the CPB score, sensitivity remained 100% with improved specificity to 88.9%. The CPB score is the preferred HIT clinical scoring tool in adult cardiac surgery patients, whereas the 4Ts score performed less effectively. A cut-off of ≥ 3 points on the CPB score could increase specificity while preserving high sensitivity, which should be validated in a prospective evaluation.

Switch from minimally invasive biventricular mechanical support to cardiopulmonary bypass during heart transplant

An easily reproducible surgical technique to switch from percutaneous minimally invasive biventricular mechanical support to cardiopulmonary bypass during heart transplantation is illustrated. After cannulation of the distal ascending aorta with a standard arterial cannula, the ProtekDuo® cannula and the ProtekSolo® Transseptal cannula were partially retracted to reach the superior and inferior vena cava, respectively, and connected to the pump circuit for the venous drainage. With this cardiopulmonary bypass configuration, orthotopic heart transplantation was routinely performed and, at the end of the procedure, the 2 cannulas were uneventfully removed.

Acute cardio-embolic stroke in a preschooler-a surgical dilemma

Myxomas are the most common primary intra-cardiac tumors in adults. Myxoma occurring in a preschooler is very rare, and cardiac surgery in acute stroke is a challenging decision. We present a rare case of acute cardio-embolic stroke in a 3-year-old child due to left atrial myxoma which was successfully treated.

Multi-omic analysis of the effects of low frequency ventilation during cardiopulmonary bypass surgery

BACKGROUND

Heart surgery with cardio-pulmonary bypass (CPB) is associated with lung ischemia leading to injury and inflammation. It has been suggested this is a result of the lungs being kept deflated throughout the duration of CPB. Low frequency ventilation (LFV) during CPB has been proposed to reduce lung dysfunction.

METHODS

We used a semi-biased multi-omic approach to analyse lung biopsies taken before and after CPB from 37 patients undergoing coronary artery bypass surgery randomised to both lungs left collapsed or using LFV for the duration of CPB. We also examined inflammatory and oxidative stress markers from blood samples from the same patients.

RESULTS

30 genes were induced when the lungs were left collapsed and 80 by LFV. Post-surgery 26 genes were significantly higher in the LFV vs. lungs left collapsed, including genes associated with inflammation (e.g. IL6 and IL8) and hypoxia/ischemia (e.g. HIF1A, IER3 and FOS). Relatively few changes in protein levels were detected, perhaps reflecting the early time point or the importance of post-translational modifications. However, pathway analysis of proteomic data indicated that LFV was associated with increased "cellular component morphogenesis" and a decrease in "blood circulation". Lipidomic analysis did not identify any lipids significantly altered by either intervention.

DISCUSSION

Taken together these data indicate the keeping both lungs collapsed during CPB significantly induces lung damage, oxidative stress and inflammation. LFV during CPB increases these deleterious effects, potentially through prolonged surgery time, further decreasing blood flow to the lungs and enhancing hypoxia/ischemia.

Anti-oxidative or anti-inflammatory additives reduce ischemia/reperfusions injury in an animal model of cardiopulmonary bypass

Severe inborn cardiac malformations are typically corrected in cardioplegia, with a cardio-pulmonary bypass (CPB) taking over body circulation. During the operation the arrested hearts are subjected to a global ischemia/reperfusion injury. Although the applied cardioplegic solutions have a certain protective effect, application of additional substances to reduce cardiac damage are of interest.

18 domestic piglets (10–15 kg) were subjected to a 90 min CPB and a 120 min reperfusion phase without or with the application of epigallocatechin-3-gallate (10 mg/kg body weight) or minocycline (4 mg/kg body weight), with both drugs given before and after CPB. 18 additional sham-operated piglets without or with epigallocatechin-3-gallate or minocycline served as controls. In total 36 piglets were analyzed (3 CPB-groups and 3 control groups without or with epigallocatechin-3-gallate or minocycline respectively; 6 piglets per group). Hemodynamic and blood parameters and ATP-measurements were assessed. Moreover, a histological evaluation of the heart muscle was performed.

Results

Piglets of the CPB-group needed more catecholamine support to achieve sufficient blood pressure. Ejection fraction and cardiac output were not different between the 6 groups. However, cardiac ATP-levels and blood lactate were significantly lower and creatine kinase was significantly higher in the three CPB-groups. Markers of apoptosis, hypoxia, nitrosative and oxidative stress were significantly elevated in hearts of the CPB-group. Nevertheless, addition of epigallocatechin-3-gallate or minocycline significantly reduced markers of myocardial damage. Noteworthy, EGCG was more effective in reducing markers of hypoxia, whereas minocycline more efficiently decreased inflammation.

Conclusions

While epigallocatechin-3-gallate or minocycline did not improve cardiac hemodynamics, markers of myocardial damage were significantly lower in the CPB-groups with epigallocatechin-3-gallate or minocycline supplementation.

Cytokine clearance with CytoSorb® during cardiac surgery: a pilot randomized controlled trial

Background

Cardiopulmonary bypass (CPB) is often associated with degrees of complex inflammatory response mediated by various cytokines. This response can, in severe cases, lead to systemic hypotension and organ dysfunction. Cytokine removal might therefore improve outcomes of patients undergoing cardiac surgery. CytoSorb® (Cytosorbents, NJ, USA) is a recent device designed to remove cytokine from the blood using haemoadsorption (HA). This trial aims to evaluate the potential of CytoSorb® to decrease peri-operative cytokine levels in cardiac surgery.

Methods

We have conducted a single-centre pilot randomized controlled trial in 30 patients undergoing elective cardiac surgery and deemed at risk of complications. Patients were randomly allocated to either standard of care (n = 15) or CytoSorb® HA (n = 15) during cardiopulmonary bypass (CPB). Our primary outcome was the difference between the two groups in cytokines levels (IL-1a, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-10, TNF-α, IFN-γ, MCP-1) measured at anaesthesia induction, at the end of CPB, as well as 6 and 24 h post-CPB initiation. In a consecutive subgroup of patients (10 in HA group, 11 in control group), we performed cross-adsorber as well as serial measurements of coagulation factors’ activity (antithrombin, von Willebrand factor, factor II, V, VIII, IX, XI, and XII).

Results

Both groups were similar in terms of baseline and peri-operative characteristics. CytoSorb® HA during CPB was not associated with an increased incidence of adverse event. The procedure did not result in significant coagulation factors’ adsorption but only some signs of coagulation activation. However, the intervention was associated neither with a decrease in pro- or anti-inflammatory cytokine levels nor with any improvement in relevant clinical outcomes.

Conclusions

CytoSorb® HA during CPB was not associated with a decrease in pro- or anti-inflammatory cytokines nor with an improvement in relevant clinical outcomes. The procedure was feasible and safe. Further studies should evaluate the efficacy of CytoSorb® HA in other clinical contexts.

Trial registration

ClinicalTrials.gov NCT02775123. Registered 17 May 2016.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2399-4) contains supplementary material, which is available to authorized users.

The multi-disciplinary management of complex congenital and acquired tracheo-oesophageal fistulae

AIM OF THE STUDY

Complex tracheo-oesophageal fistulae (TOF) are rare congenital or acquired conditions in children. We discuss here a multidisciplinary (MDT) approach adopted over the past 5 years.

METHODS

We retrospectively collected data on all patients with recurrent or acquired TOF managed at a single institution. All cases were investigated with neck and thorax CT scan. Other investigations included flexible bronchoscopy and bronchogram (B&B), microlaryngobronchoscopy (MLB) and oesophagoscopy. All cases were subsequently discussed in an MDT meeting on an emergent basis if necessary.

MAIN RESULTS

14 patients were referred during this study period of which half had a congenital aetiology and the other half were acquired. The latter included button battery ingestions (5/7) and iatrogenic injuries during oesophageal atresia (OA) repair. Surgical repair was performed on cardiac bypass in 3/7 cases of recurrent congenital fistulae and all cases of acquired fistulae. Post-operatively, 9/14 (64%) patients suffered complications including anastomotic leak (1), bilateral vocal cord paresis (1), further recurrence (1), and mortality (1). Ten patients continue to receive surgical input encompassing tracheal/oesophageal stents and dilatations.

CONCLUSIONS

MDT approach to complex cases is becoming increasingly common across all specialties and is important in making decisions in these difficult cases. The benefits include shared experience of rare cases and full access to multidisciplinary expertise.

Preliminary results of the Multicenter Observational Study with Enoximone in Cardiac surgery (MOSEC)

BACKGROUND

Perioperative administration of Enoximone has been shown to improve hemodynamics, organ function, and inflammatory response. Aim of the present study was to evaluate the effects of Enoximone after on-pump cardiac surgery.

METHODS

A protocol for a multicenter observational study was reviewed and approved by local ethic committee. This preliminary report involves the first 29 patients enrolled, in whom Enoximone was perioperatively administered in the context of on-pump cardiac surgery. All patients enrolled were propensity-matched 1:1 with controls not receiving Enoximone, renal function was evaluated in terms of estimated glomerular filtration rate (eGFR) with the CKD-EPI equation.

RESULTS

After propensity matching, the two cohorts of patients receiving Enoximone or not did not show any significant differences among baseline characteristics. Patients receiving Enoximone showed a progressive improvement of eGFR at each time-point of follow-up: roughly +4.3, +10.0, and +12.3 mL/min/1.73 m² on postoperative days 2, 7, and 30; respectively. Consistently, maximum difference versus baseline was +12.6 mL/min/1.73 m² (or +19.3%) among Enoximone patients vs +3.3 mL/min/1.73 m² (or +4.4%) among controls (p = 0.02). Multivariable regression analysis (R²-adjusted 0.47) showed only age (β -0.53; p = 0.01), preoperative eGFR (β -0.39; p = 0.02), diabetes (β 2.1; p = 0.01), cardio-pulmonary bypass duration (β 0.08; p = 0.05), and Enoximone administration (β -0.74; p = 0.05) to be independently correlated with delta eGFR variation on day 30.

CONCLUSION

These preliminary results show that perioperative Enoximone administration improved renal function in patients undergoing on-pump cardiac surgery. Further studies are needed to confirm these findings.

Early health outcome and 10-year survival in patients undergoing redo coronary surgery with or without cardiopulmonary bypass: a propensity score-matched analysis

OBJECTIVES

To investigate the in-hospital health outcome and 10-year survival in patients undergoing redo coronary surgery with (redo-CABG) or without (redo-OPCAB) cardiopulmonary bypass.

METHODS

A total of 349 redo coronary surgery patients were identified from our registry. Of these, 143 redo-OPCAB patients (40.97%) were compared with 206 redo-CABG patients. To minimize the bias, we also conducted propensity score matching. In Matched Analysis A, 111 redo-OPCAB patients with any type of primary cardiac operation were compared with 111 redo-CABG cases. In Matched Analysis B, 84 redo-OPCAB patients with isolated coronary surgery as their primary operation were compared with 84 redo-CABG patients. We assessed for all 3 analyses a composite of in-hospital mortality, acute kidney injury, stroke and severe low cardiac output requiring intra-aortic balloon pump. In addition, we assessed 1-, 5-, and 10-year survival.

RESULTS

In the unmatched analysis, redo-CABG was associated with higher usage of intra-aortic balloon pump (10 vs 3%, P = 0.01) and composite compared with redo-OPCAB (25 vs 16%, P = 0.06) and similar 10-year survival (67.2 vs 68.5%, log-rank test: P = 0.78). Matched Analysis A showed similar rates of composite (15 vs 21%, P = 0.25) and 10-year survival (65.1 vs 60.8%, log-rank test: P = 0.5). Matched Analysis B showed reduction of the composite (19 vs 8%, P = 0.04), less in-hospital mortality (5 vs 0%, P = 0.13), 4.5 times less need for intra-aortic balloon pump (2 vs 11%, P = 0.02) favouring redo-OPCAB and a similar 10-year survival (71.6 vs 71.7%, log-rank test: P = 0.61).

CONCLUSIONS

Redo-OPCAB surgery is feasible, safe and effective with improved in-hospital outcome and similar 10-year survival compared to redo-CABG.

Neurological complications are avoidable during CABG

Objective:

To review the incidence of stroke in patients undergoing CABG and the impact of a preventive strategy adopted at tertiary care unit of cardiac surgery.

Methods:

The data of all patients who underwent isolated CABG (N= 722) from July 2016 to August 2017 at Faisalabad Institute of Cardiology was retrieved for this retrospective study. All operations were done on cardiopulmonary bypass and cold blood cardioplegia. Numeric data was summarized as Mean ± Standard Deviation while categoric variables were summarized into frequency and percentage.

Results:

Mean age of patients was 53.83±8.8 years. Mean Parsonnet and Logistic EuroScore were 4.3±3.2 and 3.3±0.9 respectively. Forty nine patients (6.78%) had significant carotid artery disease. Mean number of grafts was 2.8±0.82. Diabetes was present in 27.8% patients. Neurological complications were noticed in 14 patients (1.94%) who included 12 permanent paralyses. Further subgroup analysis revealed that 67 patients who were operated by single clamp technique remained free of neurological complications. This is clinically remarkable finding but due to small population size it is statistically non- significant.

Conclusion:

The incidence of neurological complications can be reduced significantly by adopting the appropriate preventing measures. Use of Single Clamp technique may be the reasons of such a low incidence of stroke in this study.

Routine Application of Bloodless Priming in Neonatal Cardiopulmonary Bypass: A 3-Year Experience

A restrictive transfusion strategy led us to routinely try to conduct donor-blood free open-heart surgery even in neonates. The cardio-pulmonary bypass (CPB) circuit was minimized by priming volumina at 73 ml for the smallest patients with body weight up to 2.5 kg and 85-95 ml for those with body weight of more than 2.5 kg, and by positioning the console as close as possible to operation table. Measures were applied to save blood during the procedure. Transfusion threshold of 8 g/dl hemoglobin was retained. Effort was made to avoid transfusion while on CPB or to postpone transfusion towards CPB end. From 2013 to 2015, 149 consecutive neonates underwent 150 open-heart procedures without blood in priming volume. Weight was lower than 2.5 kg in five instances. The most frequent operations were arterial switch operation (n = 54) and Norwood procedure (n = 17). Transfusion-free operation was achieved in 44 procedures. The great majority (42/44 = 95%) involved biventricular repair and included 50% (27/54) of arterial switch operations. 106 patients were transfused: 63 mostly towards CPB end, and 43 after coming off bypass. Transfusion-free procedures were associated with postoperative lower lactate concentration (p = 0.0013) and shorter duration of mechanical ventilation (p = 0.0009). Seven patients were discharged from hospital without getting any transfusion of blood or blood products. In conclusion, routine application of bloodless priming in neonatal cardiopulmonary bypass is safe and beneficial. It results into a good number (29%= 44/150) of transfusion-free operations. Postponing transfusion towards CPB end favors an overall restrictive transfusion strategy for all patients.

A head to head evaluation of 8 biochemical scanning tools for unmeasured ions

We aimed to evaluate the sensitivity and specificity of 8 biochemical scanning tools in signalling the presence of unmeasured anions. We used blood gas and biochemical data from 15 patients during and after cardio-pulmonary bypass. Sampling time-points were pre-bypass (T1), 2 min post equilibration with priming fluid containing acetate and gluconate anions (T2), late bypass (T3) and 4 h after surgery (T4). We calculated the anion gap (AG), albumin-corrected anion gap (AGc), whole blood base excess (BE) gap, plasma BE gap, standard BE gap and the strong ion gap (SIG), plus 2 new indices-the unmeasured ion index (UIX) and unmeasured plasma anions according to the interstitial, plasma and erythrocyte acid-base model (IPEua). Total measured plasma concentrations of acetate and gluconate [XA] were proxies for unmeasured plasma anions. [XA] values (mmol/L) were 1.41 (0.87) at T1, 11.73 (3.28) at T2, 4.80 (1.49) at T3 and 1.36 (0.73) at T4. Corresponding [albumin] values (g/L) were 32.3 (2.0), 19.8 (2.6), 21.3 (2.5) and 29.1 (2.3) respectively. Only the AG failed to increase significantly at T2 in response to a mean [XA] surge of >10 mEq/L. At an [XA] threshold of 6 mEq/L, areas under receiver -operator characteristic curves in rank order were IPEua and UIX (0.88 and 0.87 respectively), SIG (0.81), AGc (0.79), standard BE gap (0.77), plasma BE gap (0.71), BE gap (0.70) and AG (0.59). Similar ranking hierarchies applied to positive and negative predictive values. We conclude that during acute hemodilution UIX and IPEua are superior to the anion gap (with and without albumin correction) and 4 other indices as scanning tools for unmeasured anions.

Acute mesenteric ischemia after cardio-pulmonary bypass surgery

Acute mesenteric ischemia (AMI) is a highly-lethal surgical emergency. Several pathophysiologic events (arterial obstruction, venous thrombosis and diffuse vasospasm) lead to a sudden decrease in mesenteric blood flow. Ischemia/reperfusion syndrome of the intestine is responsible for systemic abnormalities, leading to multi-organ failure and death. Early diagnosis is difficult because the clinical presentation is subtle, and the biological and radiological diagnostic tools lack sensitivity and specificity. Therapeutic options vary from conservative resuscitation, medical treatment, endovascular techniques and surgical resection and revascularization. A high index of suspicion is required for diagnosis, and prompt treatment is the only hope of reducing the mortality rate. Studies are in progress to provide more accurate diagnostic tools for early diagnosis. AMI can complicate the post-operative course of patients following cardio-pulmonary bypass (CPB). Several factors contribute to the systemic hypo-perfusion state, which is the most frequent pathophysiologic event. In this particular setting, the clinical presentation of AMI can be misleading, while the laboratory and radiological diagnostic tests often produce inconclusive results. The management strategies are controversial, but early treatment is critical for saving lives. Based on the experience of our team, we consider prompt exploratory laparotomy, irrespective of the results of the diagnostic tests, is the only way to provide objective assessment and adequate treatment, leading to dramatic reduction in the mortality rate.