Peroperative cardiogenic shock suggesting acute coronary syndrome as initial manifestation of Lyme carditis.

Carditis can complicate Lyme disease in an estimated <5% of cases, and cardiogenic shock and severe cardiac arrhythmias are described with electrocardiographic abnormalities that could be suggestive of coronary manifestations. We report a case of severe persistent biventricular heart failure complicated by cardiac arrhythmias as initial manifestation of a Lyme disease developing peroperatively electrocardiographic abnormalities suggesting acute transmural myocardial infarction.

Risk factors for meticillin resistance and outcome of Staphylococcus aureus bloodstream infection in a Belgian university hospital.

The aim of this study was to identify institution-specific risk factors for meticillin resistance in Staphylococcus aureus bloodstream infection (BSI) and to evaluate the impact of meticillin resistance on mortality. A total of 154 episodes of S. aureus BSI were identified between 1 January 2002 and 31 December 2004: 66 meticillin-resistant S. aureus (MRSA) BSI and 88 meticillin-susceptible S. aureus (MSSA) BSI. Seventy-eight episodes (51%) were considered to be community-acquired and 76 (49%) as nosocomial. Risk factors associated with MRSA BSI included not living at home (P=0.001), prior antibiotic exposure (P=0.002), insulin-requiring diabetes (P=0.028) and nosocomial BSI (P=0.031), especially more than 12.5 days after admission. There was an association between BSI-related mortality and the following variables: septic shock (P<0.001), endocarditis (P=0.002) and MRSA BSI (P=0.021). In conclusion, S. aureus BSI is a serious condition, especially when septic shock or endocarditis occurs, and is aggravated by meticillin resistance. We advise glycopeptides as empirical therapy for patients not arriving from home, those exposed to antibiotics, and those with insulin-requiring diabetes and/or nosocomial BSI.

The Brussels sedation scale: use of a simple clinical sedation scale can avoid excessive sedation in patients undergoing mechanical ventilation in the intensive care unit.

Sedation is an important component of patient comfort in the intensive care unit (ICU), especially in those undergoing mechanical ventilation. Sedation that is too light or too deep can have important consequences, and therefore assessment of the degree of sedation should be an important part of patient management. Although there are many methods available to assess the degree of sedation, none is ideal. Therefore, we developed a new sedation scale and analysed its clinical impact in the management of patients undergoing mechanical ventilation. The study comprised two consecutive phases. In the first phase, the medical team did not use a sedation scale. In the second phase, the medical staff used the new sedation scale, comprising five levels, depending on the perceived degree of sedation: levels 1 and 2 = oversedation; levels 3 and 4 = correct sedation; and level 5 = undersedation. There were no significant differences in mean or highest levels between patients in the two phases (mean 2.89 (SD 0.11) vs 2.67 (0.13), P = 0.22; highest 3.16 (0.11) vs 3.10 (0.14), P = 0.78). However, the lowest level was significantly greater in patients in the second phase than in those in the first phase (2.61 (0.11) vs 2.16 (0.13); P = 0.011), indicating that the number of patients with excessive sedation was significantly reduced with the introduction of this scale. Thus the use of this scale can have a real clinical impact for patients undergoing mechanical ventilation, principally by avoiding excessive sedation.

Sensory block extension during combined spinal and epidural.

BACKGROUND AND OBJECTIVES: During a combined spinal and epidural technique, extension of sensory block by epidural injection of saline or bupivacaine has been demonstrated and attributed to a volume effect or to the combination of a volume effect with a local anesthetic effect. This two-part study was designed to evaluate the time dependency of the volume effect and the local anesthetic effect on the mechanism of spinal block extension. METHODS: We performed two prospective studies. Thirty patients were randomized in each study. A combined spinal and epidural was performed in a sitting position in all groups. The patients in the first study received 15 mg hyperbaric bupivacaine intrathecally and were placed supine 2 minutes after spinal injection. They received 10 mL epidural saline either 5 minutes after spinal (group A) or 20 minutes after spinal (group B) compared to a control group (group C). The patients in the second study received 12.5 mg hyperbaric bupivacaine intrathecally and were placed supine 5 minutes after spinal injection. They then received epidurally either 10 mL saline 7 minutes after spinal (group D) or 10 mL bupivacaine 7 minutes after spinal (group E) or nothing (group F). Sensory block levels were assessed by a loss of sensation to cold using ether. RESULTS: In the first portion of this study, in group A, area under the curve of sensory block levels by time from 10 to 40 minutes after spinal injection, and maximum sensory block levels were significantly higher (P < .05) compared to groups B and C. In the second portion of the study, sensory block levels were comparable at all times in the three groups. CONCLUSIONS: During a combined spinal and epidural technique with the use of hyperbaric bupivacaine, the volume effect is time dependent and is seen when epidural top up is done soon after spinal injection. This volume effect is abolished when patients are left seated for 5 minutes after spinal injection. The local anesthetic effect is not demonstrated when high sensory block levels are achieved by spinal injection.

Labour analgesia in a patient with carnitine palmityl transferase deficiency and idiopathic thrombocytopenic purpura.

We report a case of a woman with carnitine palmityl deficiency (CPT) and idiopathic thrombocytopenic purpura, presenting in active labour at 38 weeks gestation. We discuss different anaesthetic factors involved with both diseases, and we propose an optimal management of such cases. Neuraxial analgesia with minimal motor blockade is indicated in early labour because it is necessary to alleviate stress in order to avoid rhabdomyolisis associated with CPT deficiency. Neuraxial analgesia is also needed because the theoretical risk of performing a caesarean section is higher than in a normal population, first because labour must be kept as short as possible and secondly because the possible thrombocytopenic in the baby precludes the use of instrumental delivery.

Hemodynamic changes during laparoscopic gastroplasty in morbidly obese patients.

BACKGROUND: In nonobese patients, peritoneal insufflation has consistently been shown to influence parameters of preload and afterload as well as cardiac output. Obese patients have an abnormal and particular cardiovascular status. The aim of this study was to investigate the hemodynamic changes induced by an increase of intra-abdominal pressure in morbidly obese patients (MOP). METHODS: Standard general anesthesia was administered to 15 informed MOP (body mass index > 40 kg/m2) scheduled for laparoscopic gastroplasty. Hemodynamic parameters were measured by thermodilution through a pulmonary artery catheter and through invasive blood pressure monitoring. RESULTS: CO2 insufflation with an intra-abdominal pressure of 17 mmHg caused a significant increase of mean arterial pressure (MAP) (33%, P = 0.005), mean pulmonary arterial pressure (MPAP) (40%, P = 0.001), pulmonary capillary wedge pressure (PCWP) (41%, P = 0.001), and central venous pressure (CVP) (55%, P = 0.001). The increase in diastolic filling pressures could be due to an increase in the filling volume or to a decrease in diastolic compliance. Ventricular volumes were not measured but we speculate that the rise in CVP, PCWP and MPAP is due to an increase in intrathoracic pressure as judged by the increase of pulmonary airway pressure. Stroke volume fell slightly (11%, P = 0.008), because of a reduction in transmural pressure and a fall in effective preload. Cardiac output rose slightly (16%, P = 0.005) because of an increase in heart rate (15%, P = 0.014) probably induced by sympathetic stimulation, which only became fully operative after 15 minutes. CONCLUSIONS: When compared to nonobese patients our obese patients tolerated the pneumoperitoneum surprisingly well, without experiencing fall in cardiac output. The hemodynamic consequences of peritoneal insufflation seem to be different in obese and nonobese patients.

Changes in pulmonary mechanics during laparoscopic gastroplasty in morbidly obese patients.

BACKGROUND: Obesity is an important respiratory risk factor after abdominal surgery. Laparoscopic surgical techniques seem beneficial in obese patients in terms of respiratory morbidity, with a faster return to normal respiratory function. However, there is little information about intraoperative respiratory mechanics and about patient tolerance to abdominal insufflation in the morbidly obese. METHODS: We studied respiratory mechanics and arterial blood gases in 15 morbidly obese patients (mean BMI = 45) undergoing laparoscopic gastroplasty under general anaesthesia and controlled ventilation. Respiratory mechanics were analysed using side-stream spirometry. RESULTS: When compared to preinsufflation values, servocontrolled abdominal insufflation to 2.26 kPa caused a significant decrease in respiratory system compliance (31%), a significant increase in peak (17%) and plateau (32%) airway pressures at constant tidal volume with a significant hypercapnia but no change in arterial O2 saturation. Respiratory system compliance and pulmonary insufflation pressures returned to baseline values after abdominal deflation. CONCLUSION: These alterations in pulmonary mechanics are less than those observed with comparable degrees of abdominal inflation in non-obese patients, and were well tolerated. From the point of view of intraoperative respiratory mechanics, laparoscopic surgery is safe in morbidly obese patients.

Methaemoglobinemia induced by a low dose of prilocaïne during interscalenic block.

Methaemoglobinemia is a rare but well known complication of the use of prilocaïne in locoregional anaesthesia. We report a case of methaemoglobinemia following the administration of a low dose of prilocaïne for an interscalenic bloc. We suggest some hypotheses to explain this phenomenon. This case illustrates the necessity of pulse oximetry monitoring in all patients receiving prilocaïne during locoregional anaesthesia.

The calcium channel blocker nifedipine fails to inhibit leucocyte elastase release during cardiopulmonary bypass.

Circulating concentrations of leucocyte elastase were measured in 16 adult patients undergoing cardiopulmonary bypass (CPB) with a flat-sheet membrane oxygenator. Eight patients (Group I) received the calcium channel blocker nifedipine (9 micrograms.kg-1 x h-1) during CPB. Eight patients (Group II) did not receive any calcium channel blocker during surgery and served as the control group. Elastase concentrations were measured at 7 time points: 2 before, 2 during, and 3 after CPB. The bypass procedure was associated with elevation in elastase concentrations (P < 0.001). Comparing to baseline values elastase concentrations were significantly elevated (P < 0.05) 60 min after the start of CPB and on all measurements done after CPB. Elastase concentrations correlated with the duration of CPB (rs = 0.76, P < 0.001), and were not influenced by nifedipine infusion as revealed by comparing the two groups. This study demonstrates moderate elastase release during CPB with a flat-sheet membrane oxygenator and fails to confirm inhibition of elastase release by nifedipine infusion during CPB.

Perioperative mapping of parahisian accessory pathways.

UNLABELLED: In 1989, two patients were operated for deep septal "parahisian" pathways in our institution. Three different mapping techniques were used. (1) Epicardial activation mapping with a belt of 21 bipolar electrodes positioned around the heart. This belt was positioned either on the atrial or on the ventricular side of the atrioventricular annulus in order to localize both the atrial and the ventricular insertion of the bypass tract. (2) Right intra-atrial activation mapping on the normothermic beating heart with a bipolar hand-held probe. (3) Right intra-atrial cryomapping at 0 degrees C. The "parahisian" pathways are remote from the epicardium and the pattern of epicardial activation is different from that of the free-wall pathways. Case 1: The electrophysiological study showed a concealed anteroseptal bypass tract. The peroperative atrial epicardial mapping during orthodromic tachycardia (OT) showed simultaneous activation of the posteroseptal area and of the basis of the right appendage. Right intra-atrial mapping during OT showed an anteroseptal "parahisian" pathway. Case 2: The ECG and electrophysiological study showed a right posterior pathway. The first site of epicardial ventricular activation during atrial stimulation was the right posterior area, 30 ms after the onset of the delta wave. The first site of epicardial atrial activation during OT was the posteroseptal area. The right intra-atrial mapping showed a posteroseptal "parahisian" bypass tract. This localization was confirmed with cryomapping. CONCLUSIONS: Some patterns of epicardial mapping may suggest the presence of a deep septal "parahisian" bypass tract: retrograde atrial activation at different sites (mimicking activation among multiple pathways); delay between the delta wave and the first epicardial electrogram. Right intra-atrial activation and cryomapping are useful to confirm the diagnosis.

[Localization of the accessory pathway and surgical treatment in Wolf-Parkinson White syndrome]. / Localisation de la voie accessoire et traitement chirurgical dans le syndrome de Wolf-Parkinson-White.

The accessory bypass tracts are responsible for many episodes of supraventricular arrhythmias in man. The Wolff-Parkinson-White syndrome is the best example. These arrhythmias can be refractory to the medical treatment and are sometimes lethal. Different techniques can be used to destroy these pathways. The surgical dissection is the most widely accepted technique. The accessory pathways are made of working muscle and are neither visible, nor palpable by the surgeon. The electrical properties of these pathways are used to localize them. These techniques are either non-invasive or invasive. The non-invasive techniques consist of the careful analysis of the surface electrocardiogram in sinus rhythm and during tachycardia. The invasive techniques consist of a pre-operative electrophysiological study and intra-operative mapping. The electrophysiological study consists of the introduction of multiples catheters inside the heart through peripheral veins. The intra-operative mapping consists of measurements done on the surface or inside the heart after the chest has been open. After precise localization of the areas of insertion of these abnormal tracts the surgeon proceeds with the dissection, starting either on the epicardial or on the endocardial side of the heart. The surgical results are excellent and there are only few complications. These techniques were used to operate six patients presenting with the Wolff-Parkinson-White syndrome.

Leaflet escape of a mitral Duromedics prosthesis. Case report.

This article reports a case of leaflet embolization of a mitral Edwards-Duromedics prosthesis. The patient had abrupt onset of acute pulmonary edema and was initially treated medically for 3 days. Fluoroscopy showed only one freely moving leaflet and the other was (incorrectly) assumed to be blocked in the closed position. The patient received IV thrombolysis for another 3 days and was finally operated. He died 8 days later from sepsis and the leaflet was recovered at autopsy in the abdominal aorta. Leaflet escape of a mitral Edwards-Duromedics prosthesis is a rare, potentially curable mode of valve failure. Correct interpretation of clinical signs and symptoms and of fluoroscopy should allow early diagnosis and surgical therapy.

Coronary vasospasm after myocardial revascularisation. Treatment by verapamil.

Coronary vasospasm occurring after myocardial revascularisation must be quickly and efficiently treated to avoid the haemodynamic complications that it may cause. Treatment by nitroglycerin intravenously (i.v.) is not always efficient and an alternate possibility of treatment is essential. During the period from March 1982 to August 1983, we observed in our institution three patients with coronary vasospasms occurring after myocardial revascularisation which did not respond to nitroglycerin i.v. and were successfully treated by verapamil. Recurrence of vasospasm was prevented in those cases by verapamil perfused i.v. (dosage: 0.37 to 0.75 microgram/kg/min). The clinical evolution of these 3 cases are described here. Dosages of verapamil used to treat and to prevent the incident are discussed. The limitations of this therapy are briefly reviewed.

Evolution of vecuronium requirements for stable mechanical effect: comparison with or without previous succinylcholine administration.

To evaluate possible interactions between residual succinylcholine and vecuronium, the amount of vecuronium required to maintain the twitch height (TH) at 10% of its initial value was measured over a 90-min period by the on-demand infusion method in two series of 15 adult patients (ASA class I-II). One group, the vecuronium treatment (V) group, received 70 micrograms X kg-1 of vecuronium and the on-demand infusion. The second group, the succinylcholine-vecuronium treatment group (SV), was given 30 micrograms X kg-1 of vecuronium and on-demand infusion 5 min after the complete recovery of TH after administration of 1 mg X kg-1 of succinylcholine. During the first 10 min, the amount of vecuronium required to maintain TH at 10% of its control was significantly greater in the group given V than in the group given SV, 15122 +/- 856 (mean +/- SEM) vs 9851 +/- 486 micrograms X m-2 X hr-1 (P less than 0.001). Thereafter, the amount of vecuronium required to maintain TH at 10% of control was similar: 2808 +/- 275 and 3068 +/- 206 micrograms X m-2 X hr-1. When the infusion of vecuronium was stopped after 90 min, the time required for spontaneous recovery from 25 to 75% of control TH levels was similar: 20.1 +/- 3.3 min in the group given V and 18.9 +/- 2.5 min in the group given SV (not significant). We conclude that after a vecuronium on-demand infusion of long duration (lasting more than 90 min), previous succinylcholine administration does not interfere with late vecuronium requirements and the spontaneous rate of recovery of TH.

Fourrier analysis demonstrate EEG slowing after circulatory arrest at 20 degrees C.

The electroencephalographic (EEG) monitoring in infants and children submitted to cardiac surgery under circulatory arrest (CA) and deep hypothermia (20 degrees C) (DH) is usually performed by display or record without analysis. These data disclose the reappearance of EEG activity but give no qualitative analysis of EEG recovery after CA. The electrical activity of the brain was monitored in these conditions by spectral analysis (fast Fourrier transformation with on-line processing). Spectral analysis of the EEG signal recorded during open heart surgery in nine infants and children operated under DH with, in five cases, CA is presented and discussed. The Fourrier analysis demonstrate in all patients with long CA (more than 30 min.) a spectral abnormality, namely the absence of fast activity (8-24 Hz) at least for the remainder of the operation. This abnormality was not present in operations without CA and was only transient after CA of shorter duration.

Haemodynamic effects of midazolam in the anaesthetized patient with coronary artery disease.

The haemodynamic effects of midazolam 0.25 mg/kg administered intravenously were studied in eight anaesthetized patients suffering from coronary artery disease. Heart rate, systemic and pulmonary pressures, right atrial pressure, capillary pressure and cardiac output were measured 2, 5, 8 and 12 min after injection of midazolam and were compared with reference values collected before the commencement of the haemodynamic test. The cardiovascular condition of all the patients followed the same course after the injection of midazolam. The greatest variations were seen at the twelfth minute, with the exception of capillary pressure where the largest decrease was noted at the eighth minute. These variations, expressed as a percentage of the initial values, were: mean arterial pressure -17% (P less than 0.01); capillary pressure -23.5% (eight minute, P less than 0.01); heart rate - 9% (P less than 0.01); cardiac index -9% (P less than 0.01); systemic vascular resistance -12% (eighth minute, P less than 0.01). The stroke volume was well maintained (+0.1% NS). These haemodynamic variations were accompanied by a favourable evolution of the endocardial viability ratio (EVR), +12% (P less than 0.01). The slight tachycardia occasionally seen on induction of anaesthesia with midazolam was not seen in this group of patients. We conclude that these haemodynamic variations leading to an increase in EVR support the use of midazolam as a supplement to fentanyl anaesthesia for patients with coronary artery disease.