Breast surgery and peripheral blocks. Is it worth it?

PURPOSE OF REVIEW: The objective of this review is to identify the potential of peripheral nerve blocks established over the last years for perioperative pain management in breast surgery. These new blocks will be discussed with respect to their clinical effect and necessity. RECENT FINDINGS: After case reports and cadaver studies for the Pecs block and its variations sufficient clinical data from randomized controlled trial (RCT) and meta-analyses exist now. The modified Pecs block or Pecs II leads to a reduction of postoperative 24-h opioid consumption. The recently invented Erector spine block addresses the intercostal nerves. The benefits in analgesia of this approach were tested in few RCTs and showed superiority to the control group in terms of requested postoperative morphine. Most studies showed low intraoperative opioid doses and no study more than low to moderate postoperative pain scores. SUMMARY: Taking the pain levels after breast surgery into account, the request of additional nerve blocks has to be pondered against the potential risks and resource requirement. To reduce or avoid intraoperative or postoperative opioids, an ultrasound-guided Pecs II block proves to be the best option for perioperative pain relief.

[Modification of perioperative psychiatric drug therapy]. / Perioperative Modifikation der psychiatrischen Dauermedikation - Wann sollte umgestellt oder pausiert werden?

Apart from cardiovascular, pulmonary and metabolic drugs, many patients scheduled for surgery are taking antidepressive or antipsychotic drugs. Some of these psychiatric drugs may interfere with anesthetics. The anesthesiologist has to decide whether or not to continue the psychiatric medication during the perioperative period. Since the discontinuation of psychiatric drugs may lead to withdrawal syndromes, the decision should be made in accordance with the attending psychiatrist. Should the discontinuation of any psychiatric drug be recommended, it may be prudent to involve the attending surgeon in order to postpone the procedure, since the modification of psychiatric drugs may take several days.Prospective randomized data about the perioperative modification of psychiatric drugs are scarce. Thus, recommendations in this regard must rely on physiological and pharmacological principles, case reports and published expert opinions. In this article we use the available data to answer the question of a journal reader regarding the perioperative modification of Opipramol therapy for a 59-year-old patient scheduled for elective shoulder surgery.

[The DGAI training module 2 in anaesthetic focussed sonography: vascular sonography]. / DGAI-zertifizierte Seminarreihe Anästhesie Fokussierte Sonografie - Modul 2: Gefäßsonografie.

Modul 2 will provide the theory and practical training of the sonographically guided puncture of central and peripheral veins and arteries. In doing so patients of all age groups are taken into consideration. Combined with the content of the other modules this series of workshops, which was initiated by our society, might be a first step in defining a new core competency of our specialty. The confident use of ultrasound in vascular puncture sharpens our dedicated professional competence and will contribute to continuously improve the quality and safety of anaesthesiologic patient care.

[The DGAI training module 3 in anaesthetic focussed sonography: neurosonography]. / DGAI-zertifizierte Seminarreihe Anästhesie Fokussierte Sonografie - Modul 3: Neurosonografie.

Identification of the right puncture site and the target structures are mandatory in performing nerve blocks. Ultrasound is a new method, that visualizes target structures as well as the injection and spread of local anaesthetic solution. The presented module 3 neurosonography is part of the didactic concept "anaesthesiology focussed sonography" developed by the german society of anaesthesiology and intensive care. It contains all essential nerve blocks of the upper and lower limb. Additionally the structural requirements to provide the course are included.

Delayed systemic air embolism in a child with severe blunt chest trauma treated with high-frequency oscillatory ventilation.

PURPOSE: Trauma is the leading cause of death in children over one year of age. Even with optimal field care, blunt chest trauma with hemoptysis is a potentially fatal injury due to exsanguination or arterial air embolism. Most often, cardiovascular collapse that is unresponsive to therapy develops shortly after endotracheal intubation and initiation of positive pressure ventilation. We present a case of arterial air embolism after blunt chest trauma that manifested atypically late, i.e., one hour after initiation of positive pressure ventilation. CLINICAL FEATURES: A 13-yr-old Caucasian boy was admitted to the emergency room after he had been run over by a car. While lung protective ventilation, including high frequency oscillatory ventilation, was performed, an alveolar to pulmonary venous fistula developed. Although the complication was diagnosed quickly, involvement of the cerebral and coronary arteries resulted in irreversible cerebral damage and fatal hemodynamic collapse. Necropsy confirmed severe damage of the right pulmonary lower lobe with involvement of the pulmonary vessels. CONCLUSION: Patients with blunt chest trauma and hemoptysis present a diagnostic dilemma with limited therapeutic options.

Interscalene brachial plexus block for open-shoulder surgery: a randomized, double-blind, placebo-controlled trial between single-shot anesthesia and patient-controlled catheter system.

INTRODUCTION: Interscalene brachial plexus block (ISB) is widely used as an adjuvant regional pain therapy in patients undergoing major shoulder surgery and has proved its effectiveness on postoperative pain reduction and opioid-sparing effect. METHOD: This single-center, prospective, double-blind, randomized and placebo-controlled study was to compare the effectiveness of a single-shot and a patient-controlled catheter insertion ISB system after major open-shoulder surgeries. Seventy patients were entered to receive an ISB and a patient-controlled interscalene catheter. The catheter was inserted under ultrasound guidance. Patients were then assigned to receive one of two different postoperative infusions, either 0.2% ropivacaine (catheter group) or normal saline solution (single-shot group) via a disposable patient-controlled infusion pump. RESULTS: The study variables were amount of rescue medication, pain at rest and during physiotherapy, patient satisfaction and incidence of unwanted side effects. The ropivacaine group revealed significantly less consumption of rescue medication within the first 24 h after surgery. Incidence of side effects did not differ between the two groups. CONCLUSION: Based on our results, we recommend the use of interscalene plexus block in combination with a patient-controlled catheter system under ultrasound guidance only for the first 24 h after major open-shoulder surgery.

[Regional anesthesia as a useful alternative to general anesthesia? Overview of the current data]. / Regionalanästhesie als sinnvolle Alternative zur Allgemeinanästhesie? Uberblick über die aktuelle Datenlage.

Neuromuscular disorders are rare and often not very well diagnosed diseases. They can be separated in prejunctional, junctional or postjunctional diseases. General anesthesia is connected with a higher risk, therefore regional anesthesia could often be regarded with favour and could be a safe alternative. Because of the lack of systematically studies and guidelines the decision choosing a regional anesthesia is always a risk-benefit-analysis. This and also the detailed preoperative neurological status must, because of forensic reason, exactly be documented.

Ultrasound use in non-cardiac surgery.

Ultrasound is used in anaesthesia for diagnostic and interventional reasons. This article gives the anaesthesiolgoist an overview about the relevant indications for ultrasound in non-cardiac surgical patients. Other chapters will focus in more detail on different aspects of ultrasound use in non-cardiac anaesthesia. Echocardiography is a monitoring tool for cardiac structures and function. In the anaesthetized patient the transoesophageal approach is preferred due to the unrestricted ultrasound view to the heart. Its use for non-cardiac surgery is discussed. The use of transcutaneous ultrasound in anaesthesia is mainly interventional: The puncture rate for vascular access e.g. central venous catheterization is higher and the procedure can be performed safer under continuous sonographic guidance. Nerve blockade under direct visualisation of target and accompanying structures has amplified the regional anaesthetic methods. The major nerve blocks are described and discussed.

Acute respiratory distress induced by repeated saline lavage provides stable experimental conditions for 24 hours in pigs.

Surfactant depletion is most often used to study acute respiratory failure in animal models. Because model stability is often criticized, the authors tested the following hypotheses: Repeated pulmonary lavage with normal saline provides stable experimental conditions for 24 hours with a PaO2/FiO2 ratio < 300 mm Hg. Lung injury was induced by bilateral pulmonary lavages in 8 female pigs (51.5 +/- 4.8 kg). The animals were ventilated for 24 hours (PEEP: 5 cm H2O; tidal volume: 6 mL/kg; respiratory rate: 30/min). After 24 hours the animals were euthanized. For histopathology slides from all pulmonary lobes were obtained. Supernatant of the bronchoalveolar fluid collected before induction of acute respiratory distress syndrome (ARDS) and after 24 hours was analyzed. A total of 19 +/- 6 lavages were needed to induce ARDS. PaO2/FiO2 ratio and pulmonary shunt fraction remained significantly deteriorated compared to baseline values after 24 hours (P < .01). Slight to moderate histopathologic changes were detected. Significant increases of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 were observed after 24 hours (P < .01). The presented surfactant depletion-based lung injury model was associated with increased pulmonary inflammation and fulfilled the criteria of acute ling injury (ALI) for 24 hours.

An in-vivo metabolic test for detecting malignant hyperthermia susceptibility in humans: a pilot study.

INTRODUCTION: In vitro contracture testing to diagnose malignant hyperthermia (MH) susceptibility requires a muscle biopsy, which may be associated with severe side effects for the patient. After investigation of several different protocols, we present a less invasive metabolic test that involves IM injection of caffeine and halothane, and subsequent measurement of interstitial lactate to differentiate between MH susceptible (MHS) and MH non-susceptible (MHN) individuals. METHODS: Two microdialysis probes with attached microtubing for trigger injection were inserted into the lateral vastus muscle of eight previously diagnosed MHS patients (representing three genetic variants Gly2434Arg, Thr2206Met, and Arg614Cys), seven MHN patients, and seven control individuals. After equilibration and lactate baseline recording, a single bolus of 200 muL caffeine 80 mM and a suspension of 200 muL halothane 4%V/V in soy bean oil (triggers) were injected locally. Lactate was measured spectrophotometrically. Data are presented as medians and interquartile ranges. RESULTS: Although baseline lactate values were similar in the investigated groups before trigger injection, caffeine increased local lactate in MHS patients significantly more (2.0 [1.8-2.6] mM) than in MHN (0.8 [0.6-1.1] mM) or in control individuals (0.8 [0.6-0.8 mM]). Similarly, halothane lead to a significant lactate increase in MHS compared to MHN and control individuals (8.6 [3.7-8.9] mM vs 0.9 [0.5-1.1] mM and 1.7 [0.9-2.3] mM, respectively). However, a relevant increase of lactate was observed in one MHN and in two control individuals. Systemic hemodynamic and metabolic variables did not differ between the investigated groups. DISCUSSION: Metabolic monitoring of IM lactate after local caffeine and halothane injection may allow less invasive testing to detect MH susceptibility, without systemic side effects.

[Modification of perioperative drug therapy in cardiovascular, pulmonary or metabolic disease]. / Perioperative Modifikation der Dauermedikation bei kardiovaskulären, pulmonalen und metabolischen Erkrankungen.

Almost 50 % of all patients that are evaluated preoperatively by an anesthesiologist are receiving concurrent medication. Many of the prescribed drugs can be omitted during the perioperative period. However, perioperative cessation of certain drug therapies may cause decompensation of primarily compensated diseases. After reading this CME article, the reader should be able to decide whether any cardiovascular, pulmonary or antidiabetic drug therapy should be continued or ceased during the perioperative period, respectively.

Comparison of arterial and central venous cannulations using ultrasound guidance in pigs.

OBJECTIVE: To evaluate the feasibility of ultrasound guided vascular access in pigs by comparing central venous and arterial cannulation techniques. ANIMALS: Twenty-two healthy female Pietrain pigs, 14-18 weeks old and weighing 51.1 +/- 4.3 kg (mean +/- SD). STUDY DESIGN: Comparative animal trial. MATERIALS AND METHODS: After induction of general anaesthesia, cannulation of the external jugular vein and internal carotid artery was attempted using real-time ultrasound guidance. The quality of the ultrasound picture was assessed on an analogue scale from 1 (excellent) to 5 (insufficient). Vessel size, cannulation success rate, number of puncture attempts and time from first puncture attempt until insertion of the Seldinger wire were recorded. RESULTS: Cannulation was successful in all but one animal in which a cut-down technique was performed. The arteries were significantly smaller than the veins (p < 0.001) resulting in a significantly prolonged cannulation time (p = 0.032) for insertion of arterial catheters without differences in success rate. In 89% of attempted cannulations, the Seldinger wire was inserted within 5 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: In anaesthetized pigs undergoing instrumentation for biomedical research, ultrasound-guided vascular access is a simple and rapid alternative to surgical cut-down. In veterinary anaesthesia, the technique might be useful in sedated or anesthetized pigs in which arterial or central venous access is required.

Intramuscular injection of sevoflurane detects malignant hyperthermia predisposition in susceptible pigs.

BACKGROUND: The authors hypothesized that intramuscular sevoflurane injection allows diagnostic differentiation between malignant hyperthermia-susceptible (MHS) and -nonsusceptible (MHN) pigs by measurement of intramuscular lactate and carbon dioxide partial pressure (PCO2), and that dantrolene reduces the sevoflurane-induced PCO2 increase. METHODS: With approval of the local animal care committee, microdialysis probes with attached microtubing for sevoflurane injection were placed in the adductor muscles of nine MHS and six MHN pigs, and PCO2 probes with microtubing were positioned in the triceps muscle of eight MHS and six MHN pigs. After equilibration, sevoflurane boluses at different concentrations and a sevoflurane-dantrolene bolus were injected synchronously. Lactate, pyruvate, and glucose as well as PCO2 were measured spectrophotometrically, and the rate of PCO2 increase was calculated. RESULTS: Intramuscular sevoflurane injection increased local lactate and PCO2 dose dependently, and significantly higher in MHS than in MHN pigs. Measurement of the rate of PCO2 increase allowed a distinct differentiation between single MHS and MHN pigs. No significant increase in PCO2 was found with sevoflurane and dantrolene. CONCLUSIONS: Local sevoflurane induces a hypermetabolic reaction measured by PCO2 and lactate increases. The reduced PCO2 increase in MHS after sevoflurane and dantrolene injection is likely to be a result of the sevoflurane-mediated calcium release and its antagonism by dantrolene. Sevoflurane may be useful for a less invasive diagnostic test for malignant hyperthermia in humans.