Hilde M. Norum

A systematic review of comparative studies indicates that paravertebral block is neither superior nor safer than epidural analgesia for pain after thoracotomy

Abstract Background The “gold standard” for pain relief after thoracotomy has been thoracic epidural analgesia (TEA). The studies comparing TEA with paravertebral block (PVB) and recent reviews recommend PVB as a novel, safer method than TEA. Methods A systematic search of the Cochrane and PubMed databases for prospective, randomized trials (RCTs) comparing TEA and PVB for post-thoracotomy analgesia was done. We assessed how TEA and PVB were performed, methods of randomization, assessment of pain relief, and complications. Abstracts only were excluded. Results Ten studies were included, comprising 224 patients randomized to TEA, 243 to PVB. The studies were heterogeneous. Therefore, a systematic narrative review with our evaluations is presented. Only 3/10 trials reported the method of randomization. Pain during coughing was reported in only 5/10, pain assessment not specified in 5/10. Only 1/10 trials found PVB superior to TEA, but placed TEA catheters too low (<T7). TEA was superior to PVB in 1/10, during first 1.5 days. PVB and TEA were equally effective in 8/10. 5/10 trials found PVB had less hypotension or urinary retention. None of the studies used appropriate and optimal TEA: TEA was started after end of surgery in half, catheters placed too low (2/10), too high (1/10), not reported in (1/10). 7/10 infused local anaesthetic only, 2/10 added fentanyl, 1/10 added morphine, and none added adrenaline. PVB infusions had higher concentration of bupivacaine (5 mg/ml) in 2/10, 1/10 added fentanyl, 1/10 added ornipressin. Loading doses were higher in 5/10, and with more concentrated solutions in 5/10 of PVB than in the TEA group. Conclusions 10 heterogeneous, mostly small, studies comparing TEA and PVB for post-thoracotomy analgesia do not allow conclusions on which method has superior analgesic efficacy and safety. The main methodological problem was that none of the studies use optimal thoracic epidural analgesia, with siting of catheters inappropriate in some and the epidural infusion containing too concentrated local anaesthetic because opioid and adrenaline were not added. Anatomical considerations (the paravertebral space comprises parts of the epidural space and contains spinal cord arteries) and personally experienced complications with PVB (paraplegia) convince us that PVB must have higher risk of, infrequent but serious, spinal cord complications than TEA. Percutaneous PVB may puncture pleura and lung. Some surgeons expressed satisfaction with PVB because the method omits costly acute pain services for monitoring on surgical wards and saves time in the operating room. They are, however, bound to experience serious complications from PVB, sooner or later. To our knowledge, optimally conducted epidural analgesia has not been compared with PVB. Current literature and our experience with both techniques for up to four decades, indicate that PVB may be an alternative for post-thoracotomy pain when TEA is infeasible for various patient-related reasons (Breivik et al., 2009). Severely disturbed haemostasis is a contraindication for PVB and TEA. Higher concentrations of local anaesthetics are needed to obtain intercostal nerve blocks and epidural analgesia with PVB, risking local anaesthetic intoxication. Robust monitoring regimen for effects and adverse effects is as important for PVB as for TEA.

Extracorporeal membrane oxygenation support for 59 days without changing the ECMO circuit: a case of Legionella pneumonia

We report the successful use of veno-venous extracorporeal membrane oxygenation (ECMO) in a 53-year-old patient with Legionella pneumonia and acute respiratory distress syndrome (ARDS) with severe barotraumas. The patient was supported for 59 days without any changes in the ECMO circuit. This is probably the longest support ever reported using the same oxygenator.

[Regional analgesia--risks and benefits].

BACKGROUND Local anaesthetics may alleviate pain more effectively than any other anaesthetic method. In regional anaesthesia/analgesia, rare but serious complications make it necessary to always consider the risk-benefit ratio. The article discusses these issues and gives advice on effective and safe conduct. MATERIAL AND METHODS The article is based on non-systematic literature searches in the PubMed and Cochrane databases and our own experience from research and clinical work. RESULTS Regional anaesthesia is obtained by administering local anaesthetics near the spinal cord and nerve roots (spinal, epidural), spinal nerves (paravertebral), or close to peripheral nerves. Parts of the body will then become numb and paralysed. The same techniques are used for regional analgesia, but this is obtained by using more dilute solutions of local anaesthetics, and other analgesic drugs are often added. Pain impulses are inhibited, but sensation of touch and muscle functions are intact. Regional analgesia gives superior relief of pain provoked by movement. This facilitates early postoperative mobilization of patients, even after major surgery in weak patients. For these patients optimally performed regional analgesia may reduce postoperative morbidity and mortality better than general anaesthesia and opioid and non-opioid analgesics administered postoperatively. Infiltration of the wound with local anaesthetics followed by optimally dosed non-opioid and opioid analgesics is a good alternative for some types of surgery. The risk of spinal bleeding has increased due to increased patient age, routine thromboprophylaxis and frequent use of antihaemostatic drugs, including platelet inhibitors. Infections in the spinal cord are caused by insufficient hygiene. Selection of patients who are likely to benefit from regional anaesthesia/analgesia, strict hygienic precautions, optimal technique, close monitoring, and assistance from an acute pain team, as well as hospital protocols for handling rare but serious complications, have reduced the occurrence and consequences of serious complications. INTERPRETATION Optimal regional anaesthesia/analgesia may improve the postoperative result.

Increased Serum Levels of the Notch Ligand DLL1 Are Associated With Diastolic Dysfunction, Reduced Exercise Capacity, and Adverse Outcome in Chronic Heart Failure

BACKGROUND Notch receptors and ligands have been demonstrated in myocardial tissue in experimental as well as clinical heart failure (HF), and a role for Notch signaling in myocardial remodeling and disease progression may be anticipated. We hypothesized that serum levels of the Notch ligand Delta-like-1 (DLL1) would be associated with clinical and hemodynamic variables in patients with HF. METHODS AND RESULTS We measured serum DLL1 in 183 patients with chronic HF and 50 age- and sex-matched healthy control subjects by means of enzyme immunoassay. Our main findings were that (i) HF patients had significantly higher serum DLL1 levels than healthy control subjects, (ii) DLL1 levels were significantly correlated with neurohormonal activation, systemic inflammation, and impaired kidney function, (iii) high DLL1 levels were associated with diastolic dysfunction and reduced exercise capacity, but not with impaired systolic function, and (iv) in univariate analysis, but not after multivariable adjustment, high levels of DDL1 were associated with adverse outcome. CONCLUSIONS Our findings may imply that DLL1 and the Notch signaling pathways are involved in the pathophysiology of HF, potentially affecting diastolic function.

Learning from the past for the present: paravertebral blocks for thoracic surgery are not without risk.

We read the recent article by Kotemane et al. with great interest and would like to add some comments. The article documents a widespread use of paravertebral block (PVB) for analgesia after thoracic surgery. PVB seems to be regaining its former popularity, whereas thoracic epidural analgesia (TEA) as the preferred method for postoperative analgesia after thoracic surgery is challenged. We are worried that the current overenthusiastic reports of the effectiveness of PVB seem to forget the well known, and sometimes serious, complications of PVB, that were experienced during the previous wave of PVB enthusiasm about 50–70 years ago. We must not risk uncritical use of PVB by anaesthesiologists and surgeons who are unaware of these complications.

Risks of serious complications after neuraxial blocks: apparent decrease due to guidelines for safe practice?

In this issue of the Acta Anaesthesiologica Scandinavica, Mikko T. Pitkänen and co-authors analyse serious complications to spinal and epidural anaesthesia in Finland during the first decade of the present millennium. This publication is important because the results are based on hard data from the database of the no-fault insurance system in Finland, and it is unlikely that any serious complications have been missed. They estimated the numbers of neuraxial anaesthesia and analgesia procedures by obtaining correct data for 1 year (2008) and extrapolated these to the other 9 years.

Thoracic paravertebral blockade and thoracic epidural analgesia: two extremes of a continuum.

To the Editor Cowie et al. showed that dye injected into the paravertebral space spread into the epidural space of 40% of cadavers receiving such injections. This observation confirms that of Purcell et al., who showed that as much as 70% of 5 mL paravertebral injections entered the epidural space in patients. The fact that the paravertebral space communicates freely with the epidural space through the intervertebral foramina should alert clinicians administering local anesthetics into the paravertebral space, whether percutaneously (blindly or ultrasound guided) or under direct vision intraoperatively, that a paravertebral block (PVB) often becomes an epidural block, unilateral or bilateral, and may under certain circumstances also result in total spinal anesthesia. PVB is currently being touted as the preferred method for pain relief after thoracic surgery. However, on the basis of a systematic review of 10 published trials comparing thoracic PVB with thoracic epidural analgesia (TEA) for postthoracotomy analgesia, we conclude that neither method was superior or safer. These trials were small and heterogeneous and none applied optimal TEA regimens, and the paravertebral dose of local anesthetic was frequently twice that of the epidural dose. In summary, the paravertebral space communicates with the epidural space, is close to the pleural space, and contains supply arteries to the spinal cord. PVB requires injection of relatively large volumes of concentrated local anesthetic solutions, which frequently and unpredictably spread to the epidural space and possibly to the subarachnoid space. Complications do occur, and a PVB requires at least the same degree of respect for indications, contraindications, and monitoring as does a TEA. With both methods, vigilant monitoring for early symptoms of complications and timely interventions are mandatory.

Central venous catheters may be a potential source of massive air emboli during vascular procedures involving extracorporeal circulation: an experimental study

Central venous catheters are mandatory during every major procedure involving extracorporeal circulation. Air emboli potentially could enter the circulation through this device when negative pressure is applied in the venous cannula. The following experimental study was initiated by a fatal massive air embolus during a vascular procedure involving cardiopulmonary bypass. An experimental setup was established, simulating a real scenario. The experiment was performed with a 40% glycerol/water mixture which exhibits properties and fluid dynamics close to blood. A heart-lung machine provided circulation of the fluid. The flow was adjusted according to the gravitational status. A triple-lumen central venous catheter with one line open to air was lowered into the liquid. The disconnected lumen of the central venous catheter was manipulated so it approached and was located in close proximity to the venous cannula. An air flow of up to 300 ml/min could be obtained from the central venous catheter with a flow in the cardiopulmonary bypass circuit of 2.3 L/min. A linear relationship was observed between flow in the circuit and air flow. Consecutive measurements proved consistent with acceptable results, proving that a disconnected central venous catheter might, under certain circumstances, be a source of massive air emboli during cardiopulmonary bypass.

The Notch Ligands DLL1 and Periostin Are Associated with Symptom Severity and Diastolic Function in Dilated Cardiomyopathy

In dilated cardiomyopathy (DCM), adverse myocardial remodeling is essential, potentially involving Notch signaling. We hypothesized that secreted Notch ligands would be dysregulated in DCM. We measured plasma levels of the canonical Delta-like Notch ligand 1 (DLL1) and non-canonical Notch ligands Delta-like 1 homologue (DLK1) and periostin (POSN) in 102 DCM patients and 32 matched controls. Myocardial mRNA and protein levels of DLL1, DLK1, and POSN were measured in 25 explanted hearts. Our main findings were: (i) Circulating levels of DLL1 and POSN were higher in patients with severe DCM and correlated with the degree of diastolic dysfunction and (ii) right ventricular tissue expressions of DLL1, DLK1, and POSN were oppositely associated with cardiac function indices, as high DLL1 and DLK1 expression corresponded to more preserved and high POSN expression to more deteriorated cardiac function. DLL1, DLK1, and POSN are dysregulated in end-stage DCM, possibly mediating different effects on cardiac function.

Reducing risk of spinal haematoma from spinal and epidural pain procedures

Abstract Background and aims: Central neuraxial blocks (CNB: epidural, spinal and their combinations) and other spinal pain procedures can cause serious harm to the spinal cord in patients on antihaemostatic drugs or who have other risk-factors for bleeding in the spinal canal. The purpose of this narrative review is to provide a practise advisory on how to reduce risk of spinal cord injury from spinal haematoma (SH) during CNBs and other spinal pain procedures. Scandinavian guidelines from 2010 are part of the background for this practise advisory. Methods: We searched recent guidelines, PubMed (MEDLINE), SCOPUS and EMBASE for new and relevant randomised controlled trials (RCT), case-reports and original articles concerning benefits of neuraxial blocks, risks of SH due to anti-haemostatic drugs, patient-related risk factors, especially renal impairment with delayed excretion of antihaemostatic drugs, and specific risk factors related to the neuraxial pain procedures. Results and recommendations: Epidural and spinal analgesic techniques, as well as their combination provide superior analgesia and reduce the risk of postoperative and obstetric morbidity and mortality. Spinal pain procedure can be highly effective for cancer patients, less so for chronic non-cancer patients. We did not identify any RCT with SH as outcome. We evaluated risks and recommend precautions for SH when patients are treated with antiplatelet, anticoagulant, or fibrinolytic drugs, when patients’ comorbidities may increase risks, and when procedure-specific risk factors are present. Inserting and withdrawing epidural catheters appear to have similar risks for initiating a SH. Invasive neuraxial pain procedures, e.g. spinal cord stimulation, have higher risks of bleeding than traditional neuraxial blocks. We recommend robust monitoring routines and treatment protocol to ensure early diagnosis and effective treatment of SH should this rare but potentially serious complication occur. Conclusions: When neuraxial analgesia is considered for a patient on anti-haemostatic medication, with patient-related, or procedure-related risk factors, the balance of benefits against risks of bleeding is decisive; when CNB are offered exclusively to patients who will have a reduction of postoperative morbidity and mortality, then a higher risk of bleeding may be accepted. Robust routines should ensure appropriate discontinuation of anti-haemostatic drugs and early detection and treatment of SH. Implications: There is an on-going development of drugs for prevention of thromboembolic events following surgery and childbirth. The present practise advisory provides up-to-date knowledge and experts’ experiences so that patients who will greatly benefit from neuraxial pain procedures and have increased risk of bleeding can safely benefit from these procedures. There are always individual factors for the clinician to evaluate and consider. Increasingly it is necessary for the anaesthesia and analgesia provider to collaborate with specialists in haemostasis. Surgeons and obstetricians must be equally well prepared to collaborate for the best outcome for their patients suffering from acute or chronic pain. Optimal pain management is a prerequisite for enhanced recovery after surgery, but there is a multitude of additional concerns, such as early mobilisation, early oral feeding and ileus prevention that surgeons and anaesthesia providers need to optimise for the best outcome and least risk of complications.