Isabelle Michaux

Transesophageal Echocardiography for Monitoring Segmental Wall Motion During Off-pump Coronary Artery Bypass Surgery

In this prospective, observational study, we evaluated whether transesophageal echocardiography allows for monitoring left ventricular segmental wall motion during cardiac displacement for off-pump coronary artery bypass (OPCAB) surgery. On the basis of a pilot study that showed frequent loss of transgastric views during OPCAB surgery, we analyzed only midesophageal views. The midesophageal 4-chamber view, 2-chamber view, and long-axis view were recorded in 60 patients after opening the chest and placing an epicardial stabilizer on the displaced heart. Using the 16-segment model, 2 echocardiographers independently performed offline analysis of segmental wall motion. The percentage of patients in whom ≥14 left ventricular segments were readable was calculated at baseline and after cardiac displacement and placement of an epicardial stabilizer. At baseline, ≥14 segments were readable in 59 (98%) of 60 patients. After cardiac displacement, ≥14 segments were readable during 58 (76%) of 76 revascularizations of the left anterior descending coronary artery (P < 0.01 versus baseline), during 33 (83%) of 40 revascularizations of the left circumflex coronary artery (P < 0.01 versus baseline), and during 29 (94%) of 31 revascularizations of the right coronary artery (not significant). We conclude that the number of readable segments decreased after cardiac displacement but that availability of ≥14 readable segments allowed for reliable monitoring of segmental wall motion in 4 of 5 patients during OPCAB surgery.

Another case of “European hantavirus pulmonary syndrome” with severe lung, prior to kidney, involvement, and diagnosed by viral inclusions in lung macrophages

Puumala virus (PUUV) is considered a classic Old World etiologic agent of nephropathia epidemica (NE), or hemorrhagic fever with renal syndrome (HFRS). HFRS is considered to be distinct from hantavirus (cardio-)pulmonary syndrome (HPS or HCPS), described in the New World. Here, we report a severe case, which fulfilled most, if not all, Centers for Disease Control and Prevention (CDC) criteria for HPS, needing non-invasive ventilation and subsequent acute hemodialysis. However, the etiological agent was PUUV, as proved by serological testing, real-time polymerase chain reaction (PCR), and sequencing. Viral antigen was detected by specific anti-PUUV immunostaining, showing, for the first time, greenish intracytoplasmic inclusions in bronchoalveolar lavage (BAL) macrophages. This case definitely confirms that HPS can be encountered during PUUV infections. Interestingly, special findings could render the diagnosis easier, such as greenish homogeneous cytoplasmic inclusions, surrounded by a fine clear halo in BAL macrophages. Therefore, although the diagnosis remains difficult before the onset of renal involvement, the occurrence of severe respiratory failure mimicking community-acquired pneumonia must alert the clinician for possible HPS, especially in endemic areas.

Repetitive endoscopy and continuous alkaline gastric irrigation in a case of arsenic poisoning.

Background: The poor prognosis of patients with persistent gastrointestinal radio-opacities after oral arsenic poisoning supports efficient gastrointestinal decontamination as critical for survival. In a case of massive arsenic ingestion, we performed repetitive gastric endoscopy and a continuous alkaline irrigation of the stomach over several days.Case Report: A 41-year-old woman was admitted 4 hours after intentional ingestion of trivalent arsenic powder 5 g. The admission abdominal X-ray confirmed the presence of multiple gastric opacities. Initial treatment was gastric lavage with normal saline, dimercaprol chelation, and supportive therapy. Since gastric opacities persisted on the abdominal X-ray at 34 hours despite repeated gastric lavage, a gastroscopy was performed showing nonremovable agglomerates. In an attempt to achieve further gastric decontamination, we performed a continuous gastric alkaline irrigation. After 3 days of alkaline irrigation, the abdomen was normal on X-ray but the gastroscopy still showed arsenic concretions. Alkaline irrigation was continued for another 3 days until total disappearance of arsenic agglomerates at the gastroscopy. Admission urinary arsenic was 3663 μgmg/L. A total of 46.2-mg of inorganic arsenic, or less than 1% the ingested dose, was extracted from the stomach by this technique. The patient was discharged from the intensive care unit 20 days after admission without sequelae.

A randomized comparison of right ventricular function after on-pump versus off-pump coronary artery bypass graft surgery

OBJECTIVES Right ventricular dysfunction occurs very soon after conventional coronary bypass surgery with cardiopulmonary bypass and might not recover within 1 year after the operation. It has been postulated that performing coronary surgery without cardiopulmonary bypass might preserve right ventricular function. We hypothesized that right ventricular global and overall systolic functions are better preserved 3 months after off-pump surgery than after conventional coronary bypass surgery. METHODS Fifty patients scheduled for elective coronary bypass surgery were randomly assigned to conventional or off-pump surgery. Right ventricular function was assessed by means of transthoracic echocardiographic analysis the day before the operation and 3 months later. Right ventricular myocardial performance index was used as a marker of global right ventricular function, and right ventricular fractional area change was used as a marker of overall right ventricular systolic function. Peak systolic velocities of the lateral tricuspid annulus were studied to assess regional systolic function of the right ventricular free wall. RESULTS Surgical intervention was completed according to randomization in 48 of 50 patients. Demographic and perioperative characteristics were similar in the 2 groups. Over the study period, right ventricular myocardial performance index and right ventricular fractional area change did not change in comparison with the baseline values in both groups. Peak systolic velocity of the lateral tricuspid annulus was decreased significantly in both groups 3 months after the operation. There were no significant intergroup differences in any echocardiographic marker of right ventricular function. CONCLUSIONS Global right ventricular function was not better preserved 3 months after off-pump surgery than after conventional coronary bypass surgery.

Echokardiographische Beurteilung des rechten Herzens beim perioperativen und intensivmedizinischen Patienten

SummaryReliable information on the structure and function of the right heart is essential for optimal haemodynamic management of critically ill patients. The right ventricle plays a pivotal, yet often neglected role in the circulation and its failure is often responsible for haemodynamic instability and poor outcome. The low pressure pump of the right ventricle is excessively sensitive to acute increases in its afterload caused by pulmonary embolism, pulmonary vasoconstriction, left ventricular failure or inappropriate ventilator setting and, consequently, is susceptible to acute failure. Alternatively, right ventricular failure can be caused by ischaemia, infarction or volume overload. In the diagnosis of right ventricular failure, echocardiography is superior to invasive haemodynamic monitoring and allows for choosing the best therapy and following its effects. The echocardiographic study of the right heart is based on two-dimensional, M-mode, Doppler and tissue Doppler techniques. Although both transthoracic and transoesophageal methods have comparable diagnostic power, in ventilated patients with poor or inaccessible transthoracic windows the transoesophageal approach frequently has to be used. With regard to the right heart, the echocardiographic study must determine size and function of the right ventricle, estimate its preload and afterload, quantify the pressures in the pulmonary circulation, evaluate the function of tricuspid and pulmonic valves and identify intracardiac shunts, emboli or vegetations. This review covers the applications of echocardiography in the diagnosis of right heart abnormalities in perioperative, critical care and emergency settings.ZusammenfassungBei der Beurteilung des notfallmedizinischen, chirurgischen und intensivmedizinischen Patienten wurde dem rechten Herzen lange nicht die gebührende Aufmerksamkeit geschenkt. Ein Grund dafür dürfte wohl das oft zitierte, jedoch missverstandene Tierexperiment sein, in dem eine schwere Schädigung der freien Wand des rechten Ventrikels mit keinen nennenswerten Veränderungen der Hämodynamik einherging [1]. Ein anderer Grund liegt an der während langer Zeit fehlenden Möglichkeit, die Größe der Herzhöhlen sowie die intrakardialen Druckwerte und Blutflüsse im Operationssaal oder am Intensivbett zu bestimmen und im Verlauf der Behandlung zu überwachen. Diese Möglichkeit ist nun dank der breiten Verfügbarkeit der Echokardiographie gegeben. Der rechte Ventrikel spielt in der operativen und akuten Medizin eine wichtige Rolle; sein Versagen liegt einem bedeutenden Teil der hämodynamischen Instabilitäten zugrunde, und seine Funktion bestimmt den Verlauf einer Vielzahl akuter Erkrankungen (Tab. 1). Die transthorakale Echokardiographie (TTE) oder die transösophageale Echokardiographie (TOE) erlauben eine schnelle, nicht oder wenig invasive und kostengünstige Beurteilung von Struktur und Funktion des rechten Herzens direkt am Patientenbett und liefern damit wichtige, für die therapeutische Entscheidungen oftmals unentbehrliche Informationen. Dieser Artikel soll einen Überblick über die aktuellen Möglichkeiten der Echokardiographie zur Beurteilung des rechten Herzens bei akutmedizinischen Patienten geben. Der im vergangenen Heft publizierte Fallbericht „Kreislaufkollaps auf der Notfallstation“ mit den Filmsequenzen 1–4 wird am Ende des Artikels besprochen.

Intra-operative myocardial ischaemia cannot be detected by analysis of transmitral inflow patterns in patients undergoing off-pump coronary surgery

Background and objective: Transmitral inflow patterns have been used for detection of myocardial ischaemia. However, its diagnostic value has not been tested in anaesthetized and mechanically ventilated patients undergoing coronary artery bypass graft surgery. Methods: Transmitral inflow patterns were studied by transoesophageal Doppler echocardiography in 43 patients undergoing coronary artery bypass graft surgery without cardiopulmonary bypass after opening of the sternum (baseline) and during grafting of the left anterior descending artery. Peak early (E) and peak late (A) transmitral velocities and their ratio (E/A) were recorded. Myocardial ischaemia was defined by standard criteria using two‐dimensional echocardiography and seven‐lead electrocardiogram. Results: Thirty‐one patients (64 ± 8 yr, 9 women) fulfilled the predefined inclusion criteria for analysis. During distal revascularization, 16 patients showed myocardial ischaemia and 15 did not. The use of vasoactive drugs, haemodynamic findings and transmitral inflow patterns were similar in both groups at baseline and during grafting. In the ischaemic group, E was 67.1 ± 13.9 cm s−1 at baseline and 69.5 ± 23.2 cm s−1 during grafting, and the E/A ratios were 1.3 ± 0.3 and 1.4 ± 0.9, respectively. In the non‐ischaemic group, E was 64.0 ± 17.1 cm s−1 at baseline and 60.9 ± 14.8 cm s−1 during grafting, and the E/A ratios were 1.4 ± 0.7 and 1.2 ± 0.3, respectively. Conclusions: Analysis of Doppler findings of transmitral inflow patterns did not allow for detection of myocardial ischaemia during surgical revascularization of the myocardium.

Spontaneous haemoperitoneum from surreptitious ingestion of a rodenticide.

Superwarfarins have progressively replaced warfarin as rodenticides as they are more potent and have a longer anticoagulant activity. Human exposure may be complicated by spontaneous haemorrhage in various sites. We report the case of a 51-year-old woman who was admitted with spontaneous haemoperitoneum and intramural haematoma along the small intestine. After the evidence of a deficit of vitamin K1-dependent clotting factors (II, VII, IX, X), the patient admitted that she was chronically ingesting difenacoum. She was successfully treated with fresh frozen plasma and vitamin K1. Follow-up was not accepted.

Persistent heparin-induced thrombocytopenia: danaparoid cross-reactivity or delayed-onset heparin-induced thrombocytopenia? A case report.

Clinical suspicion of immune heparin-induced thrombocytopenia (HIT) requires cessation of heparin and initiation of an alternative anticoagulant. The platelet count will subsequently recover. This case report describes the clinical course of a patient after a cardiovascular surgery. HIT was clinically and biologically confirmed. Unexpectedly, the platelet count did not recover despite the arrest of heparin. Danaparoid was initiated, and thrombocytopenia persisted. Danaparoid cross-reactivity was suspected, and laboratory assay was performed. Results were misinterpreted because no comparative buffer control was performed to ensure that the platelet aggregation was caused by danaparoid. Moreover, plasma/serum must be diluted to demonstrate this effect. Danaparoid cross-reactivity was incorrectly concluded, and the patient was switched to bivalirudin. The severe thrombocytopenia persisted. Plasmapheresis was started, and platelet count finally increased. The clinical course suggested a delayed-onset HIT. This case report illustrates the need for appropriate testing to differentiate drug cross-reactivity from delayed-onset HIT.

Are Normal Echocardiographic Values Obtained by Transthoracic Echocardiography in Awake Patients Suitable for Evaluation of Cardiac Function in Anesthetized and Mechanically Ventilated Patients

To the Editor: In Table 3 of their recent review, Haddad et al. present normal values for the functional variables of the right ventricle. In the legend, the authors state that “almost all normal values had been established in nonventilated patients.” Although they stress the load dependency of the presented parameters, they offer no recommendation as to the application of these values in anesthetized and ventilated patients undergoing cardiac surgery, as they do not stress the age dependency of the tissue Doppler imaging parameters. In a prospective and randomized study, our group investigated right ventricular (RV) function in patients undergoing elective on-pump and off-pump coronary bypass surgery. The patients were clinically stable and had neither pulmonary hypertension nor a history of myocardial infarction involving the right ventricle. The day before surgery, they underwent transthoracic echocardiography that revealed normal RV global and regional function and no more than mild tricuspid regurgitation. The same patients were studied the next day using transesophageal echocardiography (TEE) after induction of balanced anesthesia, muscle relaxation, and intermittent positive pressure ventilation. TEE studies were performed during hemodynamic stability and normoventilation before opening the sternum. The transthoracic echocardiography and TEE values of three parameters obtained by spectral pulsed wave Doppler echocardiography in end expiration are reported in Table 1. The inferior tricuspid annular plane maximal systolic and diastolic velocities measured in the transgastric RV inflow view during general anesthesia and intermittent positive pressure ventilation were significantly less than those assessed during the preoperative transthoracic study in the awake and spontaneously breathing patients (submitted data). The measured values were also markedly less than those presented by Haddad et al. as normal values in Table 3 of their review. The lateral tricuspid annular plane maximal early diastolic velocities (Et) reported in our awake patients were slightly less than those reported as normal values, but quite comparable with the values reported by Alam in patients with coronary artery disease before bypass surgery, suggesting a possible preoperative diastolic dysfunction due to the coronary disease. David et al. also measured inferior tricuspid annular plane maximal systolic velocity in anesthetized coronary patients before opening the sternum and reported values of 5.2 1.2 cm/s, which are similar to those in our patients during anesthesia and mechanical ventilation. These data show that general anesthesia, muscle relaxation, and mechanical ventilation have marked effects on tissue Doppler parameters of RV systolic and diastolic function. Therefore, applying reference values obtained from awake, spontaneously breathing subjects to anesthetized and mechanically ventilated patients is associated with the risk of falsely diagnosing impaired systolic or diastolic function in patients with preserved cardiac function. There is a clear need for studies to establish normal TEE values in anesthetized and mechanically ventilated patients, even if we are aware of the difficulty separating the effects of anesthesia from those of the disease, on the different Doppler parameters. Isabelle Michaux, MD Department of Intensive Care Medicine Mont-Godinne University Hospital Université Catholique de Louvain Belgium isabelle.michaux@uclouvain.be

Echokardiographische Beurteilung des rechten Herzens beim perioperativen und intensivmedizinischen Patienten@@@Evaluation of the right heart in patients in the emergency room, the operating theatre or the intensive care unit

SummaryReliable information on the structure and function of the right heart is essential for optimal haemodynamic management of critically ill patients. The right ventricle plays a pivotal, yet often neglected role in the circulation and its failure is often responsible for haemodynamic instability and poor outcome. The low pressure pump of the right ventricle is excessively sensitive to acute increases in its afterload caused by pulmonary embolism, pulmonary vasoconstriction, left ventricular failure or inappropriate ventilator setting and, consequently, is susceptible to acute failure. Alternatively, right ventricular failure can be caused by ischaemia, infarction or volume overload. In the diagnosis of right ventricular failure, echocardiography is superior to invasive haemodynamic monitoring and allows for choosing the best therapy and following its effects. The echocardiographic study of the right heart is based on two-dimensional, M-mode, Doppler and tissue Doppler techniques. Although both transthoracic and transoesophageal methods have comparable diagnostic power, in ventilated patients with poor or inaccessible transthoracic windows the transoesophageal approach frequently has to be used. With regard to the right heart, the echocardiographic study must determine size and function of the right ventricle, estimate its preload and afterload, quantify the pressures in the pulmonary circulation, evaluate the function of tricuspid and pulmonic valves and identify intracardiac shunts, emboli or vegetations. This review covers the applications of echocardiography in the diagnosis of right heart abnormalities in perioperative, critical care and emergency settings.ZusammenfassungBei der Beurteilung des notfallmedizinischen, chirurgischen und intensivmedizinischen Patienten wurde dem rechten Herzen lange nicht die gebührende Aufmerksamkeit geschenkt. Ein Grund dafür dürfte wohl das oft zitierte, jedoch missverstandene Tierexperiment sein, in dem eine schwere Schädigung der freien Wand des rechten Ventrikels mit keinen nennenswerten Veränderungen der Hämodynamik einherging [1]. Ein anderer Grund liegt an der während langer Zeit fehlenden Möglichkeit, die Größe der Herzhöhlen sowie die intrakardialen Druckwerte und Blutflüsse im Operationssaal oder am Intensivbett zu bestimmen und im Verlauf der Behandlung zu überwachen. Diese Möglichkeit ist nun dank der breiten Verfügbarkeit der Echokardiographie gegeben. Der rechte Ventrikel spielt in der operativen und akuten Medizin eine wichtige Rolle; sein Versagen liegt einem bedeutenden Teil der hämodynamischen Instabilitäten zugrunde, und seine Funktion bestimmt den Verlauf einer Vielzahl akuter Erkrankungen (Tab. 1). Die transthorakale Echokardiographie (TTE) oder die transösophageale Echokardiographie (TOE) erlauben eine schnelle, nicht oder wenig invasive und kostengünstige Beurteilung von Struktur und Funktion des rechten Herzens direkt am Patientenbett und liefern damit wichtige, für die therapeutische Entscheidungen oftmals unentbehrliche Informationen. Dieser Artikel soll einen Überblick über die aktuellen Möglichkeiten der Echokardiographie zur Beurteilung des rechten Herzens bei akutmedizinischen Patienten geben. Der im vergangenen Heft publizierte Fallbericht „Kreislaufkollaps auf der Notfallstation“ mit den Filmsequenzen 1–4 wird am Ende des Artikels besprochen.