Endovaskuläre Kühlung oder Oberflächenkühlung?

Introduction

Time course, time necessary to achieve the target temperature and stable maintenance, as well as a controlled rewarming period are important factors influencing the outcome of patients after successful cardiopulmonary resuscitation.

Methods

After successful cardiopulmonary resuscitation a total of 49 patients were cooled via an endovascular or external cooling device to a target temperature of 33°C. Relevant cooling parameters, such as time between admission and initiation of cooling, achievement of target temperature and stable maintenance of cooling therapy, were compared between both groups.

Results

In the endovascular cooling group the target temperature was reached significantly faster (154±97 min vs. 268±95 min, p=0.0002) and showed stable and controlled maintenance of cooling therapy (deviation from target temperature: 0.189±0.23°C vs 0.596±0.61°C, p=0.00006). The rewarming phase was better controlled and length of ICU stay was shorter in the group with endovascular cooling (8.8±3 vs. 12.9±6 days).

Conclusion

Endovascular cooling offers the possibility to reach the target temperature significantly faster and a stable maintenance of therapeutic hypothermia. It is capable of a more controlled rewarming period and shortens the length of ICU stay.     

Thoracic epidural block attenuates cardiovascular response to apnea in rabbits

Purpose

Apnea is one of the potential complications during anaesthesia. If sympathetic nerve activity is blocked by epidural anaesthesia, circulatory responses to apnea might change. Our objective was to assess the potential modifying effects of epidural anaesthesia on the cardiovascular responses to apnea in the animals.

Methods

Twenty rabbits anaesthetised with pentobarbital (25 mg·kg^?1 iv, 8 mg·kg^?1·hr^?1) and pacuronium bromide (0.2 mg·kg^?1·hr^?1 iv) were randomly assigned to one of two groups: control (n = 10) and epidural (n = 10). In the control group, 0.6 ml saline, and in the epidural group, 0.6 ml lidocaine 1% was injected into the epidural space respectively. After mechanical ventilation with FIO₂ 0.4, apnea was induced by disconnecting the anaesthetic circuit from the endotracheal tube, and mean arterial pressure (MAP), heart rate (HR), and time to cardiac arrest were measured.

Results

Before apnea MAP was lower in the epidural than in the control group (73 ± 10vs 91 ± 10 mmHg,P < 0.05). Heart rate was not different between groups (264 ± 36vs 266 ± 24 bpm). Mean arterial pressure increased in the control group after apnea, but not in the epidural group. The time to cardiac arrest was less in the epidural group than in the control group (420 ± 67vs 520 ± 61 sec,P < 0.05). Heart rate decreased markedly after apnea in the control group whereas it decreased gradually in the epidural group.

Conclusion

Thoracic epidural anaesthesia attenuated cardiovascular response to apnea and reduced the time to cardiac arrest.     

Topical head cooling during rewarming after experimental hypothermic circulatory arrest

Background

The aim of this study was to evaluate the potential neuroprotective effect of topical head cooling during the first 2 postoperative hours after experimental hypothermic circulatory arrest.

Methods

Twenty pigs underwent a 75-minute period of hypothermic circulatory arrest and were randomly assigned to rewarming to 37°C or to undergo topical cooling of the head for 2 hours from the start of rewarming followed by a period of external rewarming to 37°C.

Results

The 7-day survival rate was 70% in the control group and 60% in the topical head cooling group. Despite brain tissue oxygenation, intracranial pressures, mixed oxygen venous saturation, oxygen consumption, and extraction tended to be favorable in the topical head cooling group as a clear effect of mild hypothermia. The latter group had significantly higher postoperative brain lactate and pyruvate ratios, and lactate and glucose ratios. Furthermore, the topical head cooling group had worse fluid balance throughout the postoperative period. Brain histopathologic scores were comparable with the study groups, but among 7-days survivors these scores tended to be worse in the topical head cooling group.

Conclusions

Topical cooling of the head during the first 2 postoperative hours after experimental hypothermic circulatory arrest does not appear to provide any neuroprotective effect.     

Effects of single dose methylprednisolone on patient recovery after cardiopulmonary bypass

Background

Ischaemic reperfusion injury, systemic inflammatory response and multi-organ dysfunction are not infrequent following Cardiopulmonary Bypass (CPB). We investigated the role of methylprednisolone in minimizing this state.

Subject and Methods

Hundred consecutive patients undergoing elective single heart valve replacement surgery were randomized to receive methylprednisolone 30?mg/kg (M group) or placebo (P group) after induction of anaesthesia. Data were analyzed using the??t?? test and Fischer test.

Results

The cardiac indices in the M and P group were 2.79?±?0.13?L/min/m² and 2.52?±?0.26?L/min/m² respectively (p?<?0.0001). The amount of blood loss in the test versus control group was 268.3?±?65.78?ml/24 hours versus 318.7?±?55.5?ml/24?h respectively (p?<?0.0001) and the amount of blood transfused in the test versus control group was 1.26?±?0.57 units versus 1.76?±?0.8 units respectively (p?=?0.005). Patients in the test group had a lower incidence of early postoperative fever and new-onset atrial fibrillation during the first 3?days postoperatively. There was a statistically significant reduction in the intensive care unit stay (3.52?±?1.16?days versus 4.14?±?1.29?days in the M versus P group, p?=?0.01) but not in hospital length of stay (13.7?±?1.78?days versus 14.2?±?1.52?days in the M versus P group, p?=?0.13), or in overall morbidity and mortality.

Conclusions

The use of methylprednisolone prior to initiation of CPB is associated with a more stable postoperative course with a higher cardiac index, shorter duration of Intensive Care Unit (ICU) stay and fewer blood transfusions. Methylprednisolone use also appears to be associated with a lower incidence of early postoperative fever and new-onset atrial fibrillation.     

Density determination of local anaesthetic opioid mixtures for spinal anaesthesia

Purpose

To measure the density of hyperbaric and isobaric local anaesthetics before and after addition of neuroaxial opioids to define a method for calculating any local anaesthetic/opioid mixture density based on individual component densities.

Methods

Density was determined using a volumetric pycnometer (25.0281 ± 0.0013 ml). The density of local anaesthetics (bupivacaine, lidocaine), opioids (fentanyl, morphine) and multiple anaesthetic/opioid mixtures were measured in quadruplicate and expressed in g·ml^?1, at 37°C (mean ± SD). Regression analysis was used to derive a formula for calculating the density of any anaesthetic/opioid mixture.

Results

Individual components had the following densities (g·ml^?1): bupivacaine 0.75%; 1.0252 ± 0.0001, lidocaine 5%; 1.0249 ± 0.0001, bupivacaine 0.5%; 0.9994 ± 0.0001, lidocaine 2%; 1.0000 ± 0.0001, 50μg·ml^?1 fentanyl; 0.9936 ± 0.0001, and 0.5 mg·ml^?1 morphine; 1.0001 ± 0.0001. Using regression analysis, linear relationships were demonstrated between density (D) of anaesthetic/opioid mixture and the proportion of anaesthetic in the mixture (fractional volume of anaesthetic) (r = 0.9999,P < 0.001). The following formula was derived; Density_Mixture = (D_{Local anaesthetic} ? D_Opioid) × Fractional Volume Anaesthetic + D_Opioid Comparison of calculated and measured densities for multiple clinically relevant anaesthetic/opioid mixtures showed a significant degree of correlation (r = 0.9996,P < 0.001).

Conclusion

Density of spinal anaesthetic/opioid mixtures can be calculated from the component densities and the proportion of anaesthetic in the mixture.     

Antioxidant Treatment Attenuates Intestinal Mucosal Damage and Gut Barrier Dysfunction After Major Hepatectomy. Study in a Porcine Model

Background

This study aims to evaluate whether injury of gut mucosa in a porcine model of post-hepatectomy liver dysfunction can be prevented using antioxidant treatment with desferrioxamine.

Methods

Post-hepatectomy liver failure was induced in pigs combining major (70%) liver resection and ischemia/reperfusion injury. An ischemic period of 150 minutes, was followed by reperfusion for 24 h. Animals were randomly divided into a control group (n?=?6) and a desferrioxamine group (DFX, n?=?6). DFX animals were treated with continuous IV infusion of desferrioxamine 100 mg/kg. Intestinal mucosal injury (IMI), bacterial and endotoxin translocation (BT) were evaluated in all animals. Intestinal mucosa was also evaluated for oxidative markers.

Results

DFX animals had significantly lower IMI score (3.3?±?1.2 vs. 1.8?±?0.9, p?<?0.05), decreased BT in the portal circulation at 0 and 12 h of reperfusion (p?=?0.007 and p?=?0.008, respectively), decreased portal endotoxin levels at 6 (p?=?0.006) and 24 h (p?=?0.004), decreased systemic endotoxin levels (p?=?0.01) at 24 h compared to controls. Also, 24 h post-reperfusion mucosal malondialdehyde and protein carbonyls were decreased in DFX animals compared to controls (4.1?±?1.2 vs. 2.5?±?1.2, p?=?0.05 and 0.5?±?0.1 vs. 0.4?±?0.1, p?=?0.04 respectively).

Conclusion

Desferrioxamine seems to attenuate mucosal injury from post-hepatectomy liver dysfunction possibly through blockage of iron-catalyzed oxidative reactions.     

RETRACTED ARTICLE: Diltiazem-lidocaine combination for the attenuation of cardiovascular responses to tracheal intubation in hypertensive patients

Purpose

Hypertensive patients are prone to haemodynamic changes after laryngoscopy and tracheal intubation. This study was undertaken to compare the efficacy of a combination of diltiazem and lidocaine with that of each drug alone for suppressing the cardiovascular responses to trachéal intubation.

Methods

Sixty hypertensive patients (ASA II), defined as systolic blood pressure > 160 mmHg and/or diastolic blood pressure > 95 mmHg (World Health Organization), undergoing elective surgery received, in a randomized, double-blind manner, 0.3 mg·kg^?1 diltiazem, 1.5 mg·kg^?1 lidocaine, or 0.3 mg·kg^?1 diltiazem plus 1.5 mg·kg^?1 lidocaineiv (n = 20 of each) before the initiation of laryngoscopy. Anaesthesia was induced with 5 mg·kg^?1 thiopentoneiv, and tracheal intubation was facilitated with 2 mg·kg^?1 succinylcholineiv after precurarization with 0.02 mg·kg^?1 vecuroniumiv. Changes in heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were measured before and at immediate, 1, 2, 3, 5 and 10 min after tracheal intubation.

Results

The inhibitory effects of diltiazem-lidocaine combination on cardiovascular responses to tracheal intubation was greater than those of diltiazem or lidocaine as a sole medicine (RPP; 10602 ± 1448 (combination)vs 11787 ± 1345 (diltiazem), 15428 ± 1756 (lidocaine), mean ± SD,P < 0.05).

Conclusion

Prophylactic therapy with diltiazem-lidocaine combination is more effective than diltiazem or lidocaine alone for attenuating the cardiovascular changes associated with tracheal intubation in hypertensive patients.     

Shortening of the QT Interval is Observed Soon after Sleeve Gastrectomy in Morbidly Obese Patients

Background

Morbidly obese patients have an increased risk of sudden cardiac death. It is well known that obesity prolongs the QT interval, which in turn may cause ventricular arrhythmia and sudden cardiac death. The objective of this study was to establish whether sleeve gastrectomy shortens the QT interval.

Methods

Twenty-eight consecutive patients underwent sleeve gastrectomy at our institution between September 2010 and March 2011 and were included in the study. The indications for bariatric surgery were in accordance with French national guidelines. For each patient, an electrocardiogram was recorded before and then 3 months after surgery. The corrected QT (QTc) was determined independently by two physicians.

Results

The mean body mass index was 45.27?±?6.09 kg/m² before surgery and 38.32?±?5.19 kg/m² 3 months after surgery. The mean weight loss over this period was 20.71?±?7.57 kg. The QTc interval was 427?±?18.6 ms (415.7?±?12.06 in men and 428.4?±?18.96 in women) prior to surgery and was significantly lower 3 months after surgery (398.6?±?15.5 ms overall, 391.3?±?7.63 in men, and 399.6?±?16.02 in women). The QTc interval decreased in all individual patients (by an average of 28.5?±?15.6 ms overall, 24.3?±?8.38 in men, and 29?±?16.23 in women). Weight loss and decreased QTc interval were not significantly correlated (p?=?0.88).

Conclusion

Sleeve gastrectomy in morbidly obese patients was associated with a significantly lower QTc interval 3 months after surgery. These findings imply that bariatric surgery might reduce the risk of sudden cardiac death in this patient population.     

Beating heart repair of secondum atrial septal defect without aortic cross clamp—a safe alternative

Aim

Determine the safety and efficacy of On pump beating heart repair of Atrial Septal Defect (ASD) with regard to postoperative neurocognitive function and to determine myocardial oxygen extraction during the procedure.

Methods and material

The prospective study included 70 consecutive patients with Secondum ASD randomly assigned to two groups Beating Heart Group (Gp1) and Arrested Heart Group (Gp2) each having 35 patients. Gp1 patients underwent beating heart ASD with normothermic bypass without cross-clamping the aorta. Gp2 patients had conventional surgery with normothermic bypass and cardioplegic arrest. All patients were evaluated preoperatively (D0) and postoperatively on 10th day (D10) and 6 months (D6mths) for neurocognitive functions. We also compared myocardial oxygen extraction and total costs incurred.

Results

On pump beating heart repair of secondum ASD without aortic cross clamp reduces cardiopulmonary bypass time min₀ vs (39.4?±?13.2 vs 58.6?±?15.4, p?=?0.000) and total cost in rupees (26733.4?±?3117.8 ; 31357.1?±?1748.8, p?=?0.029). There was no neurologic deficit observed in any of our patients postoperatively. Preoperative and postoperative neurocognitive functions in either group did not show any significant intergroup or intragroup deterioration. Myocardial oxygen extraction in Vol%, though significantly more in Gp1 than in Gp2(10.2?±?2.6 ; 7.9?±?2.0, p?=?0.000) was however comparable to that seen in normal healthy beating heart. There were no mortalities

Conclusions

The technique is safe in protecting neurocognitive functions. This technique offers simple, effective, and safe alternative to cardioplegic techniques and may be safely used in majority of ASD repairs.