A year in review in Minerva Anestesiologica 2013.

BACKGROUND: We organized a training program for oral fiber optic intubation (FOI) under conscious sedation. The efficacy of the program was evaluated by comparing the performances of experts and novices. METHODS: The training procedure was divided into two sessions: a theoretical session on difficult airways, the fiber optic bronchoscope (FOB), remifentanil, topical anesthesia and patient interactions; and a session involving simulations of the FOI technique on dummies. For in vivo FOI, we enrolled patients requiring orotracheal intubation for elective surgery. Electrocardiograms, mean arterial pressure was railroaded over the fiberscope, and tracheal intubati6 and 7) FOIs, respectively, joined the study. To reach ±23 bpm, P=0.02), and RR was decreased (from 16±3 to 12±4 bpm, P<0.05). No differences were recorded between the experts and less-experienced anesthesiologists. The average duration of FOI was 3.3±2.0 min for experts and 4.2±2.4 min for novices (P=0.03). Procedures were successful in both groups, with patients in each group being equally satisfied with the procedures. CONCLUSION: This study highlights the importance of a structured FOI training program, demonstrating that it is possible to learn to perform FOI proficiently by practicing on dummies.

New drugs for epidural analgesia.

In recent years there has been a wide use of the epidural technique not only during surgery to provide anesthesia and analgesia, but also for obstetric and trauma as well as acute, chronic and cancer pain states. Nowadays there is an increase in the number of the epidural drugs. Local anesthetics and opioids are still the pharmacological agents more widely used epidurally, nevertheless other drugs from different pharmacological classes are administered as adjuvant to local anesthetics and opioids or are in various early stages of investigation. Regarding to local anesthetics, the most recent literature focuses on the new enantiomers, ropivacaine and levobupivacaine, the efficacy of which is similar to that of bupivacaine with a reduced risk of cardiotoxicity. About opioids, the other class of drugs mainly used, the debate, in the last years, concerned the physicochemical properties of morphine and of the more recent lipophilic agents, fentanyl and sufentanil, in order to explain the main differences in efficacy and safety. Other categories of agents have been investigated for epidural administration, such as alpha(2)-adrenergic agonists clonidine and dexmedetomidine. They are being used increasingly as adjuvants to local anesthetics and opioids. Ketamine and neostigmine, the more recent studied drugs for epidural use, are still under investigation and are not part of routine clinical practice.

Analgesia in thoracic surgery: review.

Post-thoracotomy pain is one of the most severe types of postoperative pain. It can last up to 2 months and can become chronic in 30% of patients. Pain relief after thoracic surgery is of particular significance, not only for ethical considerations but also for reduction of postoperative pulmonary and cardiac complications. Because of the difficulty in pain control, many approaches have been suggested, but a multimodal therapeutic strategy that provides a central or peripheral block associated with nonsteroidal anti-inflammatory (NSAID) and adjuvant drugs is now the cornerstone of treatment, offering the possibility of reducing opioid requirements and side effects. Thoracic epidural analgesia with local anesthetics and opioids is regarded as the gold standard treatment for post-thoracotomy pain management because it results in early extubation, better ventilatory mechanisms and gas exchange, decreased incidence of atelectasis, pneumonia and chronic postoperative pain. When epidural analgesia is contraindicated or cannot be performed, other regional techniques of analgesia can be used. An alternative method of providing adequate pain relief is a thoracic paravertebral block: continuous paravertebral infusion of local anesthetic via a catheter placed percutaneously or under direct vision during thoracotomy. This is effective in controlling postoperative pain and in preserving pulmonary function. Other techniques, such as intercostal and interpleural blocks, are rarely utilized, whereas a single shot of intrathecal injection of a hydrophilic opioid, such as morphine, appears to be effective. Cryoanalgesia, which is successful in the immediate postoperative period, has been abandoned for its brief duration and increased incidence of chronic pain.

Ropivacaine vs. levobupivacaine combined with sufentanil for epidural analgesia after lung surgery.

BACKGROUND AND OBJECTIVES: There are no clinical studies that compare epidural infusion of ropivacaine and levobupivacaine in patients undergoing lung surgery. The aim of this prospective, randomized double-blind study was to evaluate the efficacy and safety of two commercially available solutions of ropivacaine (0.2% w/v) and levobupivacaine (0.125% w/v) when administered by continuous epidural infusion together with sufentanil in patients undergoing lung surgery. METHODS: After obtaining informed consent, 54 patients, ASA physical status I-III undergoing lung resection, were enrolled. Patients were randomly assigned to two groups in which analgesia was performed by continuous thoracic epidural infusion of ropivacaine 0.2% w/v (Group R) or levobupivacaine 0.125% w/v (Group L) with or without sufentanil 1 microg mL(-1). After a test and a loading dose of each drug for the respective group, continuous epidural infusion, set at 5 mL h(-1), began. General anaesthesia was standardized. In the recovery room, patients were provided with intravenous morphine patient-controlled analgesia. Visual analogue scale at rest and when coughing, rescue patient-controlled analgesia morphine amount, haemodynamics, sensory and motor block, sedation, nausea and vomiting, patient satisfaction score, were evaluated within 48 h. RESULTS: The two groups were similar regarding patient characteristics, quality of analgesia, level of sensory block, morphine consumption and satisfaction score. Postoperative haemodynamic profile was stable in all the patients. Minor side-effects occurred with a similar incidence. Motor block was not seen. CONCLUSIONS: Equivalent volumes of ropivacaine (0.2% w/v) and levobupivacaine (0.125% w/v) provided similar static and dynamic analgesia with similar incidence of minor side-effects after thoracotomy.

Epidural infusion of levobupivacaine and sufentanil following thoracotomy.

A prospective, randomised, double-blind study was conducted to compare the efficacy of two doses of levobupivacaine combined with sufentanil for continuous epidural infusion following thoractomy. A total of 72 patients undergoing lobectomy or pneumonectomy were enrolled. An epidural catheter was inserted between the levels of T4 and T6 before induction of anaesthesia and a loading dose of levobupivacaine and sufentanil was administered. At the end of surgery an epidural infusion was commenced at 5 mlxh(-1) and continued for 48 h. Patients were randomly allocated to receive either levobupivacaine 0.125% (group A) or 0.0625% (group B) and all patients also received sufentanil (1 microgxml(-1)). Visual analogue pain scores after coughing (VASi) were always higher in group B (p < 0.05); VAS pain scores at rest were higher for the first 4 h and at 16 and 28 h in group B (p < 0.05). Total morphine consumption and requests number was lower in group A (p < 0.05). Better pain relief was achieved using epidural 0.125% levobupivacaine.

Changes in hemodynamics during isoflurane and propofol anesthesia: a comparison study.

OBJECTIVES: Volatile anesthetics are thought to impair cerebral autoregulation more than i.v. anesthetics. However, few comparative studies have been carried out in humans. The aim of our study was to evaluate the differences in cerebral hemodynamic changes after introduction of isoflurane (a volatile anesthetic) and propofol (an i.v. anesthetic). METHODS: Eighteen consecutive patients submitted to laparoscopic cholecystectomy were selected. After the induction, anesthesia was maintained by isoflurane (one minimum alveolar anesthetic concentration) during the first part of the surgical operation, and then by propofol (5 mg/kg/hour i.v.). Ventilation was adjusted to maintain a constant end-tidal CO(2). Middle artery flow velocity was assessed by means of transcranial Doppler ultrasonography. Arterial blood pressure, heart rate (HR), capnometry, pulse oxymetry, inspired fraction of O(2), and body temperature, were monitored. RESULTS: Cerebral artery velocity, HR, and mean arterial pressure all significantly increased from baseline after the introduction of isoflurane (p<0.05); the HR and mean arterial blood pressure showed no significant difference between the isoflurane and propofol phases. Isoflurane anesthesia induced a significant increase in cerebral blood velocity. Propofol introduction led to a significant decrease in cerebral artery velocity (p<0.05). CONCLUSIONS: Propofol but not isoflurane decreased cerebral blood velocity thus restoring cerebral autoregulation and the coupling between cerebral blood flow and cerebral metabolism.

Use of levobupivacaine for the treatment of postoperative pain after thoracotomies.

Continuous thoracic epidural analgesia with an opiod-local anaesthetic mixture is the most appropriate strategy to control postoperative pain in thoracic surgery. Levobupivacaine, the pure S(-) enantiomer of racemic bupivacaine, has less cardiotoxic and neurotoxic potential but similar anaesthetic properties of its native agent. There are no studies in thoracic surgery that had established the minimal efficient concentration of this anaesthetic when used with an epidural opioid. The advantages of administering opioids in addition to local anaesthetics in the epidural space are the possibility to decrease dose and consequently side-effects of each drug and to exploit the documented synergy between these different categories of drugs in producing segmental epidural analgesia. In our departmental study (unpublished data), 2 different concentration of levobupivacaine (Group A: 0.125% and Group B: 0.0625%) combined with sufentanil (1 mg/mL) were administered in continuous epidural post-thoracotomy infusion to investigate quality of analgesia, motor block and side-effects. An intravenous PCA system has been used in the postoperative period to evaluate rescue morphine consumption. Preliminary results showed that patients of each group reported similar VAS at rest although a better pain control during cough resulted in group A. Patients receiving levobupivacaine at 0.125% presented low incidence of nausea, vomiting and pruritus probably because of the smaller amount of rescue morphine administered. At the concentration of 0.125% epidural levobupivacaine in combination with sufentanil allowed to obtain a good pain control with no adverse effects and motor block at all.

Epidural analgesia in abdominal surgery: 0.2% ropivacaine with sufentanil.

AIM: Combining an opioid with peridural local analgesia is an excellent technique to control post-operative pain. Sufentanil is a widely used opioid agent, but its optimal dosage has not yet been defined. In this study we wanted to determine the best dose of epidural sufentanil in major surgery. METHODS: Before the operation, 45 major abdominal surgery patients received blended anesthesia through an epidural chest catheter. The patients were randomized into 3 groups of 15 subjects according to different sufentanil doses [0.2% ropivacaine combined with sufentanil at a dose of 0.5 microg/ml(-1), 0.75 microg/ml(-1), or 1 microg/ml(-1) (groups A, B and C, respectively)] administered through an epidural chest catheter connected to an elastometric pump (5 ml/h) for the first 36 postoperative hours. The level of postoperative analgesia in motion and at rest was measured using an analog visual scale (VAS-R, VAS-I). RESULTS: Analgesia was best in group A, and similar in groups B and C; 2 cases of pruritus were noted in group C. The VAS-I scores were <3 across all 3 patient groups. CONCLUSION: Epidural analgesia is an efficacious and reliable technique. The combination of 0.2% ropivacaine and 0.75 microg/ml(-1) sufentanil was found to be the optimum choice between analgesic efficacy and minor side effects, which correlated with the higher dose of sufentanil given to group C.

[Anesthesia and concomitant pathologies: anesthesia in the elderly patient]. / Anestesia e patologie concomitanti: l'anestesia nell'anziano.

With the increase in the average age of the population, more and more older persons undergo surgery. Major surgery, cardiovascular, orthopaedic and abdominal interventions expose the elderly patient to a significant risk for postoperative morbidity and mortality. This is not only related to the advanced age of these subjects, which is a recognized independent risk factor, but also to the aging process itself and to the greater prevalence of heart and lung diseases affecting this population segment. An important role is also played by the so-called physiologic modification found in subjects without recognized illnesses. Reduced organ function reserve requires accurate preoperative assessment that takes into account cardiovascular reserve and physiologic and pathologic alterations in the respiratory system that may predispose the patient to hypoxemia and favour the development of postoperative infection. Moreover, alterations in pharmacokinetics and pharmacodynamics require individualized drug dosing. Particular attention should also be directed at the prevention of postoperative cognitive disorders that favour the development of complications and negatively affect postoperative recovery of body function.

Auditory evoked potentials.

Auditory evoked potentials (AEPs) are an electrical manifestation of the brain response to an auditory stimulus. Mid-latency auditory evoked potentials (MLAEPs) and the coherent frequency of the AEP are the most promising for monitoring depth of anaesthesia. MLAEPs show graded changes with increasing anaesthetic concentration over the clinical concentration range. The latencies of Pa and Nb lengthen and their amplitudes reduce. These changes in features of waveform are similar with both inhaled and intravenous anaesthetics. Changes in latency of Pa and Nb waves are highly correlated to a transition from awake to loss of consciousness. MLAEPs recording may also provide information about cerebral processing of the auditory input, probably because it reflects activity in the temporal lobe/primary cortex, sites involved in sounds elaboration and in a complex mechanism of implicit (non declarative) memory processing. The coherent frequency has found to be disrupted by the anaesthetics as well as to be implicated in attentional mechanism. These results support the concept that the AEPs reflects the balance between the arousal effects of surgical stimulation and the depressant effects of anaesthetics. However, AEPs aren't a perfect measure of anaesthesia depth. They can't predict patients movements during surgery and the signal may be affected by muscle artefacts, diathermy and other electrical operating theatre interferences. In conclusion, once reliability of the AEPs recording became proved and the signal acquisition improved it is likely to became a routine feature of clinical anaesthetic practice.

Interleukin-6 release in the hepatic blood outflow during normothermic liver ischaemia in humans.

BACKGROUND: Liver surgery techniques have consistently improved and normothermic ischaemia of the liver is considered to be a safe procedure to reduce intraoperative haemorrhage. Hepatic failure, however, remains a significant complication. In liver ischaemia-reperfusion injury, cytokines play a key proinflammatory role. Cytokines may be part of the intercellular signalling that leads to recovery or to failure after major surgery. Moreover, they could be potential predictors of the outcome. Modulation of the pattern of cytokine response in the early postsurgery period could represent a new approach to minimise the impact of these procedures. AIMS: The aim of our study was to analyse the cytokine pattern in the hepatic blood outflow in patients undergoing surgical intervention of partial liver resection with clamping of the hepatic pedicle and liver ischaemia, and to correlate the cytokine behaviour with clinical parameters. PATIENTS: We studied eight patients (mean age 55 years) who underwent surgical intervention of liver resection during vascular exclusion of the hepatic pedicle. Patients were monitored for haemodynamic and haematological parameters during the pre-, infra- and postoperative period. METHODS: IL-I alpha, IL-6, TNF-alpha and IFN-gamma were assayed from peripheral and central vein blood at different times. Blood samples for cytokine assays were also drawn from the supra-hepatic veins after clamping of the porta hepatis. RESULTS: We found a significant increase of the IL-6 levels in the supra-hepatic samples during liver ischaemia, while the trend with IL-1alpha was less clear; IFN-gamma and TNF-alpha were undetectable with the methods used. IL-6 levels appeared to correlate positively with bilirubin and gamma-GT levels and negatively with the degree of acidosis. CONCLUSIONS: Our study confirms that during surgical ischaemic stress there is an increase of IL-6 serum levels more relevant in supra-hepatic vein blood. Cytokines could contribute to modulate the inflammatory response to liver ischaemia.

Relationship between awareness and middle latency auditory evoked responses during surgical anaesthesia.

BACKGROUND: Some studies support the view that meaningful auditory input can be processed by the brain during apparent surgical anaesthesia. Consequently, patients may be able to remember some information implicitly after anaesthesia as well through a 'dream-like process' (subconscious awareness). The aim of this study was to investigate the presence of subconscious awareness during anaesthesia and to examine its relationship to the mid-latency auditory evoked responses (MLAERs). METHODS: We studied 40 patients, ASA I-II, undergoing laparoscopic cholecystectomy. General anaesthesia was induced with thiopental 5 mg kg(-1), fentanyl 3 micro g kg(-1), and vecuronium 0.08 mg kg(-1). For the maintenance of anaesthesia, patients were randomly assigned to one of four anaesthetic regimen groups: sevoflurane+air in oxygen 40%; sevoflurane+nitrous oxide 60%; isoflurane+air in oxygen 40%; and isoflurane+nitrous oxide 60%. MLAERs were recorded before anaesthesia, at 1 MAC of inhaled anaesthetic and then 30 min after awakening. An audiotape with one of four stories was played immediately after intraoperative MLAER recording. Explicit and implicit memory was assessed 24 h after awakening. RESULTS: None of the patients had explicit recall. One of the patients from the isoflurane-air group showed implicit memory of listening to the audiotape. A dream-like process, in which they remembered implicitly the story played during anaesthesia, occurred in one of the patients from the sevoflurane-nitrous oxide group. In the patients with subconscious awareness, MLAERs were similar to that of the awake state with a Pa latency increase of less than 8.87. When there was a marked increase in Pa latency during anaesthesia, no subconscious awareness was observed. No statistically significant differences were found between Pa latency before and after anaesthesia. CONCLUSIONS: MLAERs may help to predict subconscious cerebral processing of auditory inputs during anaesthesia.

[Gas embolism during hysteroscopy. A case report]. / Embolia gassosa durante isteroscopia.

A case of gas embolism during hysteroscopy in a young woman suffering from sterility is reported. Although this surgical procedure is considered safe, however, when complications do occur, they can be severe and rapidly fatal. The importance of an accurate intraoperative monitoring for a rapid diagnosis and treatment remarkably improve the clinical picture of the patient.

Liver resections with or without pedicle clamping.

BACKGROUND: Decreasing operative bleeding during liver resection, and thus extent of transfusions, has become a main criterion to evaluate operative results of hepatectomies. Hepatic pedicle clamping (HPC) is widely used for this purpose. The aim of the study was to evaluate safety, efficacy, technique, and contraindications of HPC during liver resections, comparing results of resections performed with or without HPC. METHODS: Data from 245 liver resections were analyzed. In all, 125 resections were performed with HPC (group A), continuous in 100 cases and intermittent in 25 cases. The average duration of ischemia in group A was 39 +/- 20 minutes (range 7 to 107). In 20 cases (16%) ischemia was prolonged for 60 minutes or more. A total of 120 resections were performed without HPC (group B). Major resections were 53.6% in group A (67 cases) and 38.3% in group B (46 cases). Cirrhosis was present in 36 cases, 19 in group A and 17 in group B. RESULTS: Operative mortality was nil. Postoperative mortality was 2.9%, morbidity 22.4%. Percentage of transfused cases (34.4% versus 60.0%; P <0.001) and number of blood units per transfused case (2 +/- 1 versus 4 +/- 3; P <0.001) were lower in group A versus group B. Similar figures were found by considering only major resections. Postoperative blood chemistries did not show important differences between the two groups, and postoperative alterations were related more to extent and complexity of the operation than to length of HPC. CONCLUSIONS: HPC during liver resection is a safe and effective technique. This is demonstrated in a context where HPC is used continuously in most cases, intermittently in cases with impaired liver function and for more prolonged ischemia, and avoided in cases with limited bleeding, jaundice, and simultaneous bowel anastomoses.

Transesophageal echocardiographic assessment of hemodynamic function during laparoscopic cholecystectomy in healthy patients.

BACKGROUND: This study aimed by means of transesophageal echocardiography, to evaluate hemodynamic changes induced by pneumoperitoneum in patients with normal cardiac performance. METHODS: In this study, 11 ASA I-II patients (mean age, 39 years) with normal cardiac performance undergoing laparoscopic cholecystectomy were evaluated. A 5-MHz transesophageal biplane phased-array transducer connected to an echocardiographer was inserted after induction of anesthesia. Data were collected at three different times: before insufflation (T1), 10 min after insufflation (T2), and 5 min after desufflation (T3). At these same times, heart rate, systolic blood pressure, diastolic blood pressure, end-tidal carbon dioxide (CO(2)), and peak airway pressure were recorded. Statistical analysis was performed using one-way and two-way analysis of variance (ANOVA). A p value less than 0.05 was considered significant. RESULTS: End-systolic and end-diastolic diameters of the left ventricle, contractility, and performance parameters did not change significantly. Conversely, at insufflation, color Doppler area of the mitral backflow increased significantly (p < 0.05) when already present or showed up abruptly (T1: 0.22 +/- 0.28 cm(2); T2: 1.28 +/- 1.02 cm(2); T3: 0.49 +/- 0.53 cm(2)). CONCLUSIONS: Such an event is not interpreted as a mitral insufficiency. It is possibly the result of a "contrast effect" caused by the absorption of CO(2) microbubbles in the blood.