Isolated forearm technique: a meta-analysis of connected consciousness during different general anaesthesia regimens.

BACKGROUND: General anaesthesia should prevent patients from experiencing surgery, defined as connected consciousness. The isolated forearm technique (IFT) is the current gold standard for connected consciousness monitoring. We evaluated the efficacy of different anaesthesia regimens in preventing IFT responses. METHODS: We conducted a systematic review with meta-analysis of studies evaluating IFT in adults. Proportions of IFT-positive patients were compared for inhalational versus intravenous anaesthesia and anaesthesia brain monitor (ABM)-guided versus non-ABM-guided. RESULTS: Of 1131 patients in 22 studies, 393 (34.8%) had an IFT response during induction or maintenance. IFT-positive patients were less frequent during induction (19.7% [95% CI, 17.5-22.1]) than during maintenance (31.2% [95% CI, 27.8-34.8]). Proportions of IFT-positive patients during induction and maintenance were similar for inhalational (0.51 [95% CI, 0.38-0.65]) and intravenous (0.52 [95% CI, 0.26-0.77]) anaesthesia, but during maintenance were lower with inhalational (0.18 [95% CI, 0.08-0.38]) than with intravenous (0.48 [95% CI, 0.24-0.73]) anaesthesia. Proportions of IFT-positive patients during induction and maintenance were not significantly different for ABM-guided (0.64 [95% CI, 0.39-0.83]) and non-ABM-guided (0.48 [95% CI, 0.34-0.62]) anaesthesia but during maintenance were lower with non-ABM-guided (0.19 [95% CI, 0.09-0.37]) than with ABM-guided (0.57 [95% CI, 0.34-0.77]). Proportions of IFT-positive patients decreased significantly with increasing age and premedication use. Of the 34 anaesthesia regimens, 16 were inadequate. Studies had low methodological quality (only seven randomised controlled trials) and significant heterogeneity. CONCLUSIONS: Standard general anaesthesia regimens might not prevent connected consciousness. More accurate anaesthesia brain monitor methodology to reduce the likelihood of connected consciousness is desirable.

Perioperative benefit and outcome of thoracic epidural in esophageal surgery: a clinical review.

Surgery for esophageal cancer is a highly stressful and painful procedure, and a significant amount of analgesics may be required to eliminate perioperative pain and blunt the stress response to surgery. Proper management of postoperative pain has invariably been shown to reduce the incidence of postoperative complications and accelerate recovery. Neuraxial analgesic techniques after major thoracic and upper abdominal surgery have long been established to reduce respiratory, cardiovascular, metabolic, inflammatory, and neurohormonal complications.The aim of this review is to evaluate and discuss the relevant clinical benefits and outcome, as well as the possibilities and limits of thoracic epidural anesthesia/analgesia (TEA) in the setting of esophageal resections. A comprehensive search of original articles was conducted investigating relevant literature on MEDLINE, Cochrane reviews, Google Scholar, PubMed, and EMBASE from 1985 to July2017. The relationship between TEA and important endpoints such as the quality of postoperative pain control, postoperative respiratory complications, surgical stress-induced immunosuppression, the overall postoperative morbidity, length of hospital stay, and major outcomes has been explored and reported. TEA has proven to enable patients to mobilize faster, cooperate comfortably with respiratory physiotherapists and achieve satisfactory postoperative lung functions more rapidly. The superior analgesia provided by thoracic epidurals compared to that from parenteral opioids may decrease the incidence of ineffective cough, atelectasis and pulmonary infections, while the associated sympathetic block has been shown to enhance bowel blood flow, prevent reductions in gastric conduit perfusion, and reduce the duration of ileus. Epidural anesthesia/analgesia is still commonly used for major 'open' esophageal surgery, and the recognized advantages in this setting are soundly established, in particular as regards the early recovery from anesthesia, the quality of postoperative pain control, and the significantly shorter duration of postoperative mechanical ventilation. However, this technique requires specific technical skills for an optimal conduction and is not devoid of risks, complications, and failures.

Pain control after liver transplantation surgery.

BACKGROUND: Although post-liver transplantation pain is not as severe as expected from the size of the surgical incision, optimal pain control becomes crucial to aid compliance with the ventilator, improve respiratory function, and facilitate an early weaning from mechanical ventilation. METHODS: Because the majority of analgesics are primarily metabolized and excreted by the hepatobiliary system, a poor recovery of graft function will result in a decrease in clearance and reduced elimination of the drug. On the other hand, if the liver is working well, the metabolism of analgesics improves significantly with minimal accumulation. Morphine-based analgesia has been associated with a higher risk of sedation and respiratory depression compared with major abdominal surgical procedures. Fentanyl and sufentanil in continuous intravenous infusion may be preferred in the presence of hemodynamic instability or bronchospasm. Sufentanil produces shorter-lasting respiratory depression and long-lasting analgesia than does fentanyl. RESULTS: The provision of potent continuous analgesia, independent of the duration of infusion, and the unique pharmacokinetics, not significantly affected by the functional status of the graft, make remifentanil appropriate for the majority of liver-transplanted patients. Unlike for patients with very severe pain after major abdominal surgery, liver transplant recipients usually benefit from tramadol, either in repeated intravenous boluses or continuous intravenous infusion. Paracetamol has been included as adjuvant (or sole agent, rarely) in the analgesic treatment of mild to moderate postoperative pain. The combination treatment (paracetamol plus tramadol) is a reasonable, safe option with improved analgesia and concurrent reduction in the incidence of some opioid-related side effects. CONCLUSIONS: Frequent review of the patient's response is mandatory when potent opioids are used because dose-dependent respiratory depression is a serious and potentially life-threatening adverse effect. The benefits provided by epidural analgesia in this particular setting should be weighed against the risks because in the presence of markedly deranged perioperative blood clotting, the development of epidural hematoma represents a disastrous complication.

Liver transplantation in children with congenital cardiac defects: a case report and a short literature review.

Advances in surgical techniques and follow-up of patients with complex congenital heart disease who were corrected in childhood increasingly survive to adolescence or adulthood. Increasingly anesthesiologists encounter these cases for major noncardiac surgery, including orthotopic liver transplantation (OLT) wherein there is an augmented risk of significant perioperative hemodynamic instability. We performed a successful OLT in a 12-year-old boy with end-stage cryptogenetic liver fibrosis and hepatopulmonary syndrome who was born with a double outflow right ventricle, pulmonary atresia, and pulmonary artery hypoplasia corrected at the age of 1 month. By the time he was considered for OLT his altered pulmonary valve apparatus resulted in severe pulmonary regurgitation, dilated right atrium and ventricle, and elevated right heart pressures. After a temporarily successful angioplasty he was at first placed on the waiting list, then removed, and finally relisted following implantation of a prosthetic pulmonary valve that resulted in significant reduction of right heart pressures.

Mitochondrial protectant pramipexole prevents sex-specific long-term cognitive impairment from early anaesthesia exposure in rats.

BACKGROUND: Exposure to general anaesthesia during critical stages of brain development results in long-lasting cognitive impairment. Co-administration of protective agents could minimize the detrimental effects of anaesthesia. Co-administration of R(+)pramipexole (PPX), a synthetic aminobenzothiazol derivative that restores mitochondrial integrity, prevents anaesthesia-induced mitochondrial and neuronal damage and prevents early development of cognitive impairment. Here, we determine the protective effects of PPX into late adulthood in male and female rats. METHODS: Postnatal day 7 rats of both sexes were exposed to mock anaesthesia or combined midazolam, nitrous oxide, and isoflurane anaesthesia for 6 h with or without PPX. Cognitive abilities were assessed between 5 and 7 months of age using Morris water maze spatial navigation tasks. RESULTS: Examination of spatial reference memory revealed that female, but not male, neonatal rats exposed to anaesthesia showed slowing of acquisition rates, which was significantly improved with PPX treatment. Examination of memory retention revealed that both male and female anaesthesia-treated rats have impaired memory retention performance compared with sham controls. Co-treatment with PPX resulted in improvement in memory retention in both sexes. CONCLUSION: PPX provides long-lasting protection against cognitive impairment known to occur when very young animals are exposed to anaesthesia during the peak of brain development. Anaesthesia-induced cognitive impairment appears to be sex-specific with females being more vulnerable than males, suggesting that they could benefit more from early prevention.

Complications of non-invasive ventilation techniques: a comprehensive qualitative review of randomized trials.

Non-invasive ventilation (NIV) has become a common treatment for acute and chronic respiratory failure. In comparison with conventional invasive mechanical ventilation, NIV has the advantages of reducing patient discomfort, procedural complications, and mortality. However, NIV is associated with frequent uncomfortable or even life-threatening adverse effects, and patients should be thoroughly screened beforehand to reduce potential severe complications. We performed a detailed review of the relevant medical literature for NIV complications. All major NIV complications are potentially life-threatening and can occur in any patient, but are strongly correlated with the degree of pulmonary and cardiovascular involvement. Minor complications can be related to specific structural features of NIV interfaces or to variable airflow patterns. This extensive review of the literature shows that careful selection of patients and interfaces, proper setting of ventilator modalities, and close monitoring of patients from the start can greatly reduce NIV complications.

Early exposure to general anesthesia disturbs mitochondrial fission and fusion in the developing rat brain.

BACKGROUND: General anesthetics induce apoptotic neurodegeneration in the developing mammalian brain. General anesthesia (GA) also causes significant disturbances in mitochondrial morphogenesis during intense synaptogenesis. Mitochondria are dynamic organelles that undergo remodeling via fusion and fission. The fine balance between these two opposing processes determines mitochondrial morphometric properties, allowing for their regeneration and enabling normal functioning. As mitochondria are exquisitely sensitive to anesthesia-induced damage, we examined how GA affects mitochondrial fusion/fission. METHODS: Seven-day-old rat pups received anesthesia containing a sedative dose of midazolam followed by a combined nitrous oxide and isoflurane anesthesia for 6 h. RESULTS: GA causes 30% upregulation of reactive oxygen species (n = 3-5 pups/group), accompanied by a 2-fold downregulation of an important scavenging enzyme, superoxide dismutase (n = 6 pups/group). Reactive oxygen species upregulation is associated with impaired mitochondrial fission/fusion balance, leading to excessive mitochondrial fission. The imbalance between fission and fusion is due to acute sequestration of the main fission protein, dynamin-related protein 1, from the cytoplasm to mitochondria, and its oligomerization on the outer mitochondrial membrane. These are necessary steps in the formation of the ring-like structures that are required for mitochondrial fission. The fission is further promoted by GA-induced 40% downregulation of cytosolic mitofusin-2, a protein necessary for maintaining the opposing process, mitochondrial fusion (n = 6 pups/group). CONCLUSIONS: Early exposure to GA causes acute reactive oxygen species upregulation and disturbs the fine balance between mitochondrial fission and fusion, leading to excessive fission and disturbed mitochondrial morphogenesis. These effects may play a causal role in GA-induced developmental neuroapoptosis.

Do we need to use sugammadex at the end of a general anesthesia to reverse the action of neuromuscular bloking agents? Position Paper on Sugammadex use.

Sugammadex, the first selective relaxant-binding agent indicated to reverse the neuromuscular blockade induced during general anesthesia, was recently introduced into clinical practice. In the present report, the following issues pertinent to the use of sugammadex in anesthesia practice are discussed: the intraoperative use of NMBAs and the incidence of postoperative residual curarization (PORC); the efficacy and safety of rocuronium plus sugammadex compared to succinylcholine for rapid sequence induction; the availability of sugammadex in hospitals; and, finally, some relevant legal medical aspects. Sugammadex is considerably more expensive than neostigmine, but its use can be advocated based on its safety and efficacy profile as a reversal agent of steroidal neuro muscular blocking agents (NMBAs), and as a mean to prevent PORC. The availability of sugammadex in Italian hospitals may have a beneficial impact on patient safety. This is due to the fact that PORC is a common and dangerous condition that may lead to postoperative inhalational events, hypoxemia, and pneumonia; and at the moment, it is not completely preventable even when advanced neuro-muscolar monitoring techniques are applied". In the case of rapid sequence intubation (RSI), rocuronium (1.2 mg/kg) administration followed by sugammadex represents a better choice in terms of efficacy and safety than succinylcholine. If a new drug is proven to be safer and more efficient than the one it is replacing, hospitals should consider the new drug and make it available, at least for selected patients or in situations at risk of severe complications. It is reasonable to hypothesize that, when discussing informed consent for elective procedures, patients and families may want to know if the admitting facilities have the superior agent available, and that the absence of such agent could create concerns and complains.

Noninvasive high-frequency percussive ventilation in the prone position after lung transplantation.

Noninvasive positive-pressure ventilation (NIV), which represents a consolidated treatment of both acute and chronic respiratory failure, is increasingly being used to maintain spontaneous ventilation in lung transplant patients with impending pulmonary complications. Adding a noninvasive inspiratory support plus positive end-expiratory pressure (PEEP) has proven to be useful in preventing endotracheal mechanical ventilation, airway injury, and infections. Lung recipients with closure of the small airways in the dependent regions may also benefit from the prone position, which is helpful to promote recruitment of nonaerated alveoli and faster healing of consolidated atelectatic areas. In patients with localized or diffuse lung infiltrates, high-frequency percussive ventilation (HFPV), by either an invasive airway or a facial mask, has been adopted as an alternative ventilatory mode to enhance airway opening, limit potential respirator-associated lung injury, and improve mucus clearance. In nonintubated lung recipients at risk for volubarotrauma with conventional mechanical ventilation, it allows oxygen diffusion into the distal airways at lower mean airway pressures while avoiding repetitive cyclical opening and closing of the terminal airways. We summarize the clinical course of 3 patients with post-lung transplantation respiratory complications who were noninvasively ventilated with HFPV in the prone position. Major advantages of this treatment included gradual improvement of spontaneous clearance of bronchial secretions, significant attenuation of graft infiltrates and consolidations, a reduction in the number of bronchoscopies required, a decrease in spontaneous respiratory rate and work of breathing, and a significant improvement in gas exchange. The patients found HFPV with either standard facial mask or total mask interface to be comfortable or only mildly uncomfortable, and after the sessions they felt more restored. HFPV by facial mask in the prone position may be an interesting and attractive alternative to standard NIV, one that is more useful when implemented before full-blown respiratory failure is established.

Limits and pitfalls of haemodynamic monitoring systems in liver transplantation surgery.

Cardiac output (CO) and other hemodynamic variables measured during liver transplantation are often obtained by pulmonary artery catheter (PAC) and in many centers by the transthoracic thermodilution method and/or intraoperative transesophageal echocardiography (TEE). Newer non-invasive technology, such as the PiCCO(®) system, the LiDCO(®) Plus monitor, and the FloTrac/Vigileo(®), have been proposed as more reflective of ongoing hemodynamic response to intraoperative manoeuvres. In contrast to the standard "semicontinuous" thermodilution method, which gives information over a set period of time, the new monitoring systems use a different time period or measure over a running several beat average. It has been stated that algorithms based on arterial pulse contour analysis can potentially facilitate rapid diagnosis and prompt therapeutic interventions. However, as the use of these technologies has spread, so has the understanding of their limitations. This has led to an increased scepticism among the previously enthusiastic "pioneering" practitioners. Given the poor agreement reported in various studies on liver transplant surgery between PAC and the new "calibrated" and "uncalibrated"-derived measurements, multicenter trials aiming at evaluating the performance of the non-invasive methods in different hemodynamic conditions and dedicated monitoring-driven treatment protocols are necessary.