Monolithic thin-film lithium niobate broadband spectrometer with one nanometre resolution

Miniaturised optical spectrometers are attractive due to their small footprint, low weight, robustness and stability even in harsh environments such as space or industrial facilities. We report on a stationary-wave integrated Fourier-transform spectrometer featuring a measured optical bandwidth of 325 nm and a theoretical spectral resolution of 1.2 nm. We fabricate and test on lithium niobate-on-insulator to take full advantage of the platform, namely electro-optic modulation, broad transparency range and the low optical loss achieved thanks to matured fabrication techniques. We use the electro-optic effect and develop innovative layouts to overcome the undersampling limitations and improve the spectral resolution, thus providing a framework to enhance the performance of all devices sharing the same working principle. With our work, we add another important element to the portfolio of integrated lithium-niobate optical devices as our spectrometer can be combined with multiple other building blocks to realise functional, monolithic and compact photonic integrated circuits.

MAST: a hybrid Multi-Agent Spatio-Temporal model of tumor microenvironment informed using a data-driven approach

Motivation

Recently, several computational modeling approaches, such as agent-based models, have been applied to study the interaction dynamics between immune and tumor cells in human cancer. However, each tumor is characterized by a specific and unique tumor microenvironment, emphasizing the need for specialized and personalized studies of each cancer scenario.

Results

We present MAST, a hybrid Multi-Agent Spatio-Temporal model which can be informed using a data-driven approach to simulate unique tumor subtypes and tumor-immune dynamics starting from high-throughput sequencing data. It captures essential components of the tumor microenvironment by coupling a discrete agent-based model with a continuous partial differential equations-based model.The application to real data of human colorectal cancer tissue investigating the spatio-temporal evolution and emergent properties of four simulated human colorectal cancer subtypes, along with their agreement with current biological knowledge of tumors and clinical outcome endpoints in a patient cohort, endorse the validity of our approach.

Availability and implementation

MAST, implemented in Python language, is freely available with an open-source license through GitLab (https://gitlab.com/sysbiobig/mast), and a Docker image is provided to ease its deployment. The submitted software version and test data are available in Zenodo at https://dx.doi.org/10.5281/zenodo.7267745.

Supplementary information

Supplementary data are available at Bioinformatics Advances online.

Pedestal High-Contrast Gratings for Biosensing

High-contrast gratings (HCG) are an excellent candidate for label-free detection of various kinds of biomarkers because they exhibit sharp and sensitive optical resonances. In this work, we experimentally show the performance of pedestal HCG (PHCG), which is significantly enhanced in comparison with that of conventional HCG. PCHGs were found to provide a 11.2% improvement in bulk refractive index sensitivity, from 482 nm/RIU for the conventional design to 536 nm/RIU. The observed resonance was narrower, resulting in a higher Q-factor and figure of merit. By depositing Al2O3, HfO2, and TiO2 of different thicknesses as model analyte layers, surface sensitivity values were estimated to be 10.5% better for PHCG. To evaluate the operation of the sensor in solution, avidin was employed as a model analyte. For avidin detection, the surface of the HCG was first silanized and subsequently functionalized with biotin, which is well known for its ability to bind selectively to avidin. A consistent red shift was observed with the addition of each of the functional layers, and the analysis of the spectral shift for various concentrations of avidin made it possible to calculate the limit of detection (LoD) and limit of quantification (LoQ) for the structures. PHCG showed a LoD of 2.1 ng/mL and LoQ of 85 ng/mL, significantly better than the values 3.2 ng/mL and 213 ng/mL respectively, obtained with the conventional HCG. These results demonstrate that the proposed PHCG have great potential for biosensing applications, particularly for detecting and quantifying low analyte concentrations.

Equianalgesia, opioid switch and opioid association in different clinical settings: a narrative review

Emergency or postoperative pain often represents an authentic challenge in patients who were already on opioid treatment for chronic pain. Thus, their management requires not only the physician's ability to treat acute pain, but also competence in switching the opioid that lost efficacy. Different aspects should be considered, such as opioids titration, switching, association and equianalgesia. The objective of this paper is to provide a narrative review, which has been elaborated and discussed among clinicians through an iterative process involving development and review of the draft during two web-based meetings and via email. This expert opinion aims to facilitate the correct opioid use through appropriate practices with a focus on pain treatment in emergency and postoperative pain. Equianalgesia tables were reviewed and integrated by clinicians and researchers with expertise in anesthesia, postoperative medicine, intensive care, emergency medicine pharmacology and addiction medicine. Special populations (liver/kidney failure, elder, pediatric, pregnancy/lactation) are discussed in detail along with other critical scenarios, such as: (i) rapid pain worsening in chronic pain (aggravating pain due to disease progression or tolerance development to analgesic therapy); (ii) acute pain on maintenance treatment; and (iii) pain management of complicated patients in emergency care. Extended and updated equianalgesia tables and conversion rates for 17 different opioid formulations (of 9 different molecules) are presented as follows. Opioids remain the class that best suits clinical needs of emergency and post-operative medicine. However, it should be stressed that equianalgesia can be affected by drug-to-drug interactions and pharmacological imprecision, in a complex field where clinical experience may be the main guiding principle.

What if COVID-19 affects the child: which weapons and how to use them

Since the reports in Wuhan (China), in December 2019, of the first cluster of cases of pneumonia caused by the new Coronavirus called 2019-nCoV or SARS-CoV-2, there has been a pandemic spread of the infection. By now, we have no specific therapy to counteract this emergency. The latest epidemiological data suggest that children are just as likely as adults to get infected by the virus. Most of them show mild clinical pictures or are completely asymptomatic, but there is an increased risk for severe disease in infancy (<12 months of age) and in children with underlying medical conditions. In this article, research achievements on the treatment of pediatric SARS-CoV-2 infection are examined.

Sportomics: metabolomics applied to sports. The new revolution?

Sportomics is the application of metabolomics in sports to investigate the metabolic effects of physical exercise on individuals, whether they are professional athletes or not. Metabolomics is one of the "omics" sciences that provide a picture of the metabolic state of a person in physiological or pathological conditions. This is achieved through the analysis of metabolites present in a biological fluid, such as saliva, blood, feces, and urine. The authors revised the recent literature concerning this topic and discussed the useful information that sportomics can provide and the limits of the current experimental settings. Furthermore, in the future, sportomics analyses could be used to prevent and manage injuries as it would be known in advance if an athlete is more prone to experience muscular damage or fatigue. Following more trials, it would also be possible to set the best diet and training programs to get the best performances out of the athletes. Moreover, based on their metabolic profiles, both adults and children could choose tailored physical training in order to preserve and improve their health.

Tapentadol prolonged release in the treatment of musculoskeletal pain: an innovative pharmacological option

Musculoskeletal pain, encompassing back and osteoarthritis (OA) pain, represents the most frequent source of chronic pain in western countries, and it is particularly frequent in older adults. Remarkably, back and OA pain present, in most cases, both a nociceptive and a neuropathic component of pain. Treatment selection should, therefore, properly consider the ability of a drug to act on both components, reducing the possibility of plastic changes in the central nervous system, and consequently promoting physical rehabilitation. The pharmacological profile of tapentadol, combining synergistically µ-opioid receptor (MOR) agonist and norepinephrine reuptake inhibition (NRI) in one single molecule with a concomitant reduction in the burden of adverse events, is unique, to date, and makes this drug particularly suitable for the treatment of back pain and OA-associated pain, especially when a neuropathic component is present. Tapentadol is an innovative dual-acting analgesic molecule, which combines two mechanisms of action, namely MOR agonism and NRI. This narrative review will briefly discuss the pharmacological action of tapentadol and its rationale for use in back pain and OA.

Risk for Depression, Burnout and Low Quality of Life Among Personnel of a University Hospital in Italy is a Consequence of the Impact One Economic Crisis in the Welfare System?

BACKGROUND

Research literature suggests that burnout, depression, and a low mental quality of life (QOL) are common among health care workers. Economic crisis might have increased the burden of burnout, depression and low QOL in health care workers.

OBJECTIVES

To identify depression risk, burnout levels, and quality of life in a sample of workers of an Italian university hospital.

METHOD

Cross sectional study with comparison with two community surveys database results (n = 2000 and 1500, respectively). Overall, 522 workers accepted to take part in the study, representing a 78% response rate (out of 669 individuals).

RESULTS

The frequency of positivity at the screener for Major Depressive Disorder among health care workers was more than double than that in the standardized community sample (33.3% vs 14.1%, p<0.0001). All professionals, except the administrative staff and technicians (i.e. those who do not have contact with patients), showed a statistically higher frequency of positivity for depressive episodes compared to the controls. Among the medical staff, the highest risk was found in the surgeon units, while the lowest one was in the laboratories. Surgeons also were those most exposed to high risk of burnout, as measured by the Maslach Burnout Inventory.

CONCLUSION

Since burnout is linked to patient safety and quality of patient care, and contribute to medical errors, dedicated interventions aimed at reducing poor mental health and low quality of life in medical staff are indicated.

A systematic review of the effects of adding neostigmine to local anesthetics for neuraxial administration in obstetric anesthesia and analgesia

BACKGROUND

Drugs used in obstetric patients must accomplish two goals: efficacy and safety for both mother and fetus. Neostigmine has been co-administered epidurally and intrathecally with local anesthetics and other adjuncts in the obstetric setting. The aim of this meta-analysis was to assess the efficacy and incidence of adverse events related to the use of neostigmine in obstetric anesthesia.

METHODS

A meta-analysis of randomized-controlled human trials was conducted using the data sources Google Scholar and PubMed (updated 1 November 2014). Inclusion criteria were: random allocation to treatment; comparison of neostigmine or neostigmine with local anesthetics and/or other adjuvants versus placebo or placebo with local anesthetics and/or other adjuvants; and approval by an ethics committee.

RESULTS

The use of neostigmine as an adjuvant in neuraxial anesthesia is associated with a reduction in the dose of local anesthetic during labor analgesia and postoperative analgesia following cesarean section: mean reduction of local anesthetic (ropivacaine or bupivacaine) vs. control -4.08 (95% CI -6.7 to -1.5) mg/h (P=0.002). The risk of nausea was increased vs. control with intrathecal neostigmine (OR 8.99 [95% CI 4.74 to 17.05], P <0.001) but not with epidural neostigmine (OR 0.97 [95% CI 0.46 to 2.05], P=0.94). Use of neuraxial neostigmine was associated with a decrease in the risk of pruritus but there was no increase in the incidence of hypotension, dizziness or sedation and no effect on the incidence of abnormal fetal heart rate patterns or Apgar scores.

CONCLUSIONS

Neuraxial administration of neostigmine significantly reduces local anesthetic consumption without serious adverse side effects to the mother or fetus. However, neostigmine is only recommended for epidural administration as intrathecal use significantly increases the incidence of maternal nausea and vomiting.

Pituitary apoplexy after laparoscopic surgery: a case report

The occurrence of unprobable adverse events during laparoscopic surgery has increased over the years. Among them, pituitary apoplexy has been reported only twice. The increase in the abdominal pressure might play a role in the pituitary apoplexy, as well as hemodynamic instability, anticoagulant drugs and air-embolism due to insufflation of CO2 during pneumoperitoneum. We report a case of pituitary apoplexy during laparoscopic resection of sigmoid colon.

Metformin-associated lactic acidosis requiring hospitalization. A national 10 year survey and a systematic literature review

BACKGROUND

Metformin is known to be rarely associated with lactic acidosis, a serious condition with a poor prognosis.

AIM

To review the National Pharmacovigilance Network of the Italian Medicines Agency reporting cases of metformin-associated lactic acidosis.

MATERIALS AND METHODS

The National Pharmacovigilance Network of the Italian Medicines Agency, was searched for cases of lactic acidosis that occurred in a 10 years period (from November 2001 to October 2011). Data were analyzed, to identify associated clinical features. A systematic literature research was performed to identify other large case series on metformin associated lactic acidosis.

RESULTS

Metformin was the antidiabetic drug most frequently associated with lactic acidosis in the assessed period. Metformin-associated lactic acidosis was the most frequent serious adverse reaction related to metformin reported to the national authority (18.2% of all 650 adverse drug reactions reported). There were 59 cases of metformin-associated lactic acidosis (mortality rate of 25.4%). In most patients (89.8%) there was at least one risk factor for the occurrence of lactic acidosis. The predictors of death were low arterial blood pH and absence of acute renal failure. The systematic research of the literature identified only six case-series with more than 30 patients.

CONCLUSIONS

This is the second largest case series ever reported on metformin-associated lactic acidosis. We confirmed that this rare complication of metformin is frequently fatal. Death can be predicted when the patient arrive in the hospital with low pH and, not intuitively, if the patient has no acute kidney injury. Risk minimisation measures taken at national level to prevent this serious complication are described.

Is target opioid therapy within sight?

Control of pain has a central role in patients treatment either in advanced cancer or other terminal illnesses and in acute postsurgical or chronic non-malignant diseases. Hospitals should promote programs of research on genetic mechanism, and also biochemical and physiological aspects of pain through highly specialized labs. Opioids are the first choice drugs for moderate to severe chronic pain, especially at the end of life, and among them oral morphine is worldwide recognized by the World Health Organization and by the European Association for Palliative Care as the conventional therapy. Although this general agreement, administration of this class of drugs may be a major medical challenge due to the high effects' variability related to pharmacokinetic and pharmacodynamic parameters, such as absorption, distribution and metabolism, as well as intrinsic efficacy at the receptors involved. For such a reason, optimization of the management regime is not always reached in all the patients. Up to now no one can easily predict which patient will experience side effects or an inadequate pain control. The growing body of evidence concerning a sound genetic background of this human intervariability has prompted research on the field of a personalized therapy, focusing on single nucleotide polymorphisms (SNPs), being the most common and diffuse form of genetic variation. This review has the main goal to report the most promising human genetic polymorphisms involved in opioid treatment, and address the relationship between these polymorphisms and the clinical outcome.

Acute nephrotoxicity of NSAID from the foetus to the adult

NSAIDs are generally considered to be safe and well tolerated, but, even with the advent of selective COX-2 inhibitors, nephrotoxicity remains a concern. An impaired renal perfusion caused by the inhibition of prostaglandin synthesis is claimed like the more frequent cause of an acute renal failure due to NSAIDs, while a chronic interstitial nephritis or an analgesic nephropathy are believed the causes of a chronic renal failure. The real incidence of renal side effects of NSAIDs is still unclear and it differs between the age of the patients and the reports present in the literature. The occurrence of renal side effects following prenatal exposure to NSAIDs seems to be rare considering the large number of pregnant woman treated with indomethacin or other prostaglandin inhibitors. NSAID-related nephrotoxicity remains an important clinical problem in the newborns, in whom the functionally immature kidney may exert a significant effect on the disposition of the drugs. Instead, nephrotoxicity is a rare event in children and the risk is lower than adults. In healthy adult patients the incidence of renal adverse effects is very low, less than 1%. The risk increased with age. The elderly are at higher risk, and it is correlated at the presence of pretreatment renal disease, hypovolemia due to use of diuretics, diabetes, congestive heart failure or alteration of NSAID pharmacokinetics.

Postoperative pain treatment SIAARTI Recommendations 2010. Short version

The aim of these recommendations is the revision of data published in 2002 in the "SIAARTI Recommendations for acute postoperative pain treatment". In this version, the SIAARTI Study Group for acute and chronic pain decided to grade evidence based on the "modified Delphi" method with 5 levels of recommendation strength. Analgesia is a fundamental right of the patient. The appropriate management of postoperative pain (POP) is known to significantly reduce perioperative morbidity, including the incidence of postoperative complications, hospital stay and costs, especially in high-risk patients (ASA III-V), those undergoing major surgery and those hospitalized in a critical unit (Level A). Therefore, the treatment of POP represents a high-priority institutional objective, as well as an integral part of the treatment plan for "perioperative disease", which includes analgesia, early mobilization, early enteral nutrition and active physiokinesitherapy (Level A). In order to improve an ACUTE PAIN SERVICE organization, we recommend: --a plan for pain management that includes adequate preoperative evaluation, pain measurement, organization of existing resources, identification and training of involved personnel in order to assure multimodal analgesia, early mobilization, early enteral nutrition and active physiokinesitherapy (Level A); --the implementation of an Acute Pain Service, a multidisciplinary structure which includes an anesthetist (team coordinator), surgeons, nurses, physiotherapists and eventually other specialists; --referring to high-quality indicators in establishing an APS and considering the following key points in its organization (Level C): --service adoption; --identifying a referring anesthetist who is on call 24 hours a day; --patient care during the night and weekend; --sharing, drafting and updating written therapeutic protocols; --continuous medical education; --systematic pain assessment; --data collection regarding the efficacy and safety of the implemented protocols; --at least one audit per year. --a preoperative evaluation, including all the necessary information for the management of postoperative analgesia (Level C); --to adequately inform the patient about the risks and benefits of drugs and procedures used to obtain the maximum efficacy from the administered treatments (Level D). We describe pharmacological and loco-regional techniques with special attention to day surgery and difficult populations. Risk management pathways must be the reference for early identification and treatment of adverse events and chronic pain development.

Both right and left cervical cordotomies depress sympathetic indexes derived from heart rate variability in humans

Unilateral percutaneous cervical cordotomy, performed in humans to relieve intractable cancer pain, elicits signs of ipsilateral sympathetic block. In patients undergoing right or left percutaneous cervical cordotomy (9 per group), changes in sympathovagal balance were evaluated by spectral analysis of heart rate to confirm the sympatholytic effect of this surgical procedure and to investigate the lateralization of sympathetic cardiac control. For these purposes, heart rate variability was recorded 1 hour before cordotomy and 24 hours later. Cordotomy significantly depressed the low frequency peak (LF) of heart rate variability and increased the high frequency component (HF), when measured as a percentage of total power. As a consequence, the LF/HF ratio decreased significantly (P =.001), particularly during standing. The effects of right or left cordotomies were not significantly different. In conclusion, in humans unilateral percutaneous cervical cordotomy depresses some sympathetic indexes (LF/total power ratio and LF/HF ratio) derived from heart rate variability, irrespective of side.

Celiac block for the treatment of pancreatic pain

Neurolytic celiac plexus block (NCPB) is commonly performed to relieve pancreatic cancer pain. Since Kappis described the percutaneous NCPB, a number of variations of this technique have been proposed to improve analgesic results and minimize complications. In this article, we review and discuss techniques, results, and complications of NCPB.

The TURP syndrome: importance of expiratory ethanol measurement and high serum levels of glycine

OBJECTIVE

In a prospective study it was our intention to evaluate the reliability and the predictive value of expiratory ethanol for the early detection of the occurrence of TURP syndrome and emphasize the role of the serum levels of glycine in clinical manifestation.

METHODS

We studied 30 patients scheduled for elective traditional transuretral resection of the prostate performed with subarachnoid anesthesia. Serum sodium and glycine concentrations, serum osmolality and end-expiratory ethanol levels were monitored at scheduled intervals. Continuous heart rate and blood pressure monitoring was performed during the perioperative period in the operativing room and, later, in the recovery room. Occurrence of cardiocirculatory, respiratory and neurologic symptoms were recorded. Statistics included Bonferroni's t-test and Fisher's exact test. A decision level plot for end-expiratory ethanol level was performed for the choice of predictivity criterion.

RESULTS

In our population we identified three groups of patients: Group I (15 patients) in which no symptom was recorded; Group II (6 patients) in which non-specific anesthesia-related symptoms occurred; Group III (9 patients) in which TURP syndrome of various degree of severity was observed. In this group of patients changes in serum sodium and glycine concentrations, serum osmolality and end-expiratory ethanol levels were significantly different compared with the other two groups. In regard to end-expiratory ethanol levels, we identified a cut-off point at 0.05 mg/ml. In Group III two patients developed transient blindness. These patients had the highest serum glycine concentrations (> 4000 mumol/ml). Mortality was nil.

CONCLUSIONS

Our data show the reliability and accuracy of end-expiratory ethanol levels as a predictive test of the occurrence of TURP syndrome. Further, we emphasize the role of serum glycine concentration in the occurrence of neurologic symptoms related to the transurethral resection of the prostate.

Day surgery: the value of monitored anesthesia care and intraoperative monitoring

Recently an increasing percentage of patients is receiving care and surgical procedures in Day Surgery (DS), undergoing local or loco-regional anesthesia techniques, to which many patients appear to be rather reluctant and show fear and anxiety. The anesthesiologist can resolve this problem administering i.v. hypnotic and analgesic drugs and adjusting their level to patient's needs and type of surgery. They increase the patient's compliance to DS care and contribute to its diffusion. Nowadays, commonly used drugs permit quick changes of anesthesia depth with a fast and safe recovery but these require an appropriate monitoring in order to prevent and rapidly detect the onset of complications. In this study we analyze the peculiarity of Monitored Anesthesia Care and the appropriate intraoperative monitoring especially regarding the use of pulse oximetry.

[Management of postoperative pain in stomatology with ibuprofen L-arginine and naproxen]

BACKGROUND

The aim of this prospective, randomized study is to compare the efficacy and safety of ibuprofen L-arginine and naproxen in the treatment of postoperative dental pain.

METHODS

Seventy patients undergoing removal of impacted third molars were randomly allocated to receive 4 hours after surgery a single oral dose of either ibuprofen L-arginine 400 mg or naproxen 550 mg. Ten patients dropped out from the study because they took the study drug before the allowed time. Using a self-rating record, patients rated their pain and its relief for 1 hour after the drug administration. Remedication, if needed, and mean time of remedication were also recorded.

RESULTS

A statistically significant reduction in pain scores with respect to the baseline values was recorded 5 minutes and 15 minutes after the drug administration in the ibuprofen L-arginine and in the naproxen-treated group, respectively. The summed pain intensity difference (SPID) over 60 minutes resulted significantly higher in the ibuprofen L-arginine than in the naproxen-treated group. A complete abolition of pain 60 minutes after medication was obtained in 12/28 patients (42.9%) in the ibuprofen L-arginine and in 5/32 patients (15.6%) in the naproxen-treated group, respectively (p = 0.04). Number of patients requiring remedication, mean time of remedication and drug related adverse effects did not significantly differ in the two treatment group.

CONCLUSIONS

Global evaluation of the drugs by the patients showed ibuprofen more effective drug than naproxen.

[Treatment of postoperative pain by balanced spinal analgesia]

Postoperative pain relief has the aim to provide patient subjective comfort, to inhibit neuroendocrine and metabolic responses to surgical injury and to enhance restoration of function by allowing the patient to breathe, cough, move more easily and to begin enteral nutrition. Opioid analgesics, independently from the route of administration, are unable to provide all this. In addition to spinal opioids other drugs, such as local anesthetics, alpha 2-agonists and cholinergic drugs, may produce an antinociceptive effect when administered by spinal route. All these drugs may be administered in combination between them, realising the so called "balanced spinal analgesia". The aim of this study is to analyse the available methods for the evaluation of pharmacological interactions, the types of interaction among different spinal antinociceptive drugs and the role of balanced spinal analgesia in the treatment of postoperative pain. Analysis of the presented data shows that the spinal synergism between opioids-local anesthetics and opioids-alpha 2-agonists can be useful in the treatment of postoperative pain, because these drug combinations are able to provide a satisfactory pain control at low doses with a reduction of the adverse effects. Furthermore, the combined use of opioids-local anesthetics proved to be effective also in abolishing postoperative incident pain and in inhibiting neuroendocrine and metabolic responses to surgical injury. Especially in high risk patients this is related to a better outcome. Finally, even if the synergism between cholinergic drugs with opioids or a2-agonists have been proved, at the moment their use in man by spinal route in the treatment of postoperative pain is not advisable.

[Intravenous patient-controlled analgesia (PCA) in the treatment of postoperative pain: rationale and clinical application]

The clinical use of the patient-controlled analgesia (PCA) represents a further improvement in the treatment of post-operative pain. In this way in success due to inadequate protocols, unpredictability of the drug absorption and variability of the response to one drug or to the same pain patterns between patients can be avoided. This technique allows the patient himself to control the pain without depending upon nurses or physicians for the administration of analgesic drugs. Although the PCA is in use since several years, there are still some unresolved problems which are considered in this paper.

[Postoperative pain in pediatric patients]

Surgery is an unpleasant experience which is always related to a period of pain. In the pediatric patient this results in an important effective and metabolic-neuroendocrine manifestation. After a short review of the methods recently used to evaluate pain-qualitatively as well as quantitatively, we focused on the different techniques and drugs which can be used by the anesthesiologist to achieve an adequate control of the pain symptoms. The aim is to provide devices which can be used for different groups of age in order to guarantee the maximum efficacy in pain control with the least side effect and invasiveness.

[The neuroendocrine and metabolic response to surgical stress]

Surgical stress and post-operative pain evoke complex neuroendocrine and tissue responses aiming at defence from injury and recovery of body integrity. Such a reaction appears to be a real "hormonal storm" which is mainly induced by Sympathetic Nervous System and sympatho-adrenomedullary and hypothalamic-pituitary-adrenal systems activation and, in the periphery, by the release of inflammatory mediators at the site of injury. These substances by means of complex regulatory mechanisms and reciprocal interactions induce significant cardiovascular, metabolic, inflammatory and immunologic changes. However, this response may became excessive and contribute to an increase in postoperative morbidity and mortality. Since pain is a major factor in neuroendocrine response triggered by surgical injury every effort must be made to achieve effective intra and post-operative pain control.

[The pre-emptive analgesia in the treatment of postoperative pain]

The term "pre-emptive analgesia" implies the hypothesis that an analgesic treatment, given before nociceptive stimuli reach the Central Nervous System, could prevent or reduce the subsequent pain. The rational basis of this phenomenon, giving rise to much interest in the last years, comes from the finding that noxious stimuli cause wind-up and receptive fields expansion phenomena in the dorsal horn neurons of the spinal cord leading to hyperalgesia. Recently, many clinical trials to verify the existence of a pre-emptive effect regarding the management of postoperative pain by the administration of non steroidal antiinflammatory drugs (NSAIDs), local anesthetics and opioids have been conducted. As regards NSAIDs to date no study demonstrated a pre-emptive effect. Conflicting results emerged from trials employing local anesthetics, opioids or associations of the three classes of drugs. Thus, the "pre-emptive analgesia" represents a very important phenomenon for the basic research, but further trials must investigate its clinical impact.

Prospective randomized double-blind trial of neurolytic coeliac plexus block in patients with pancreatic cancer

BACKGROUND

In a randomized double-blind study the efficacy of neurolytic coeliac plexus block (NCPB) was compared with pharmacological therapy in the treatment of pain from pancreatic cancer.

METHODS

Twenty-four patients were divided into two groups: 12 patients underwent NCPB (group 1) and 12 were treated with pharmacological therapy (group 2). Immediate and long-term efficacy, mean analgesic consumption, mortality and morbidity were evaluated at follow-up. Statistical analysis was performed with the unpaired t test, Mann-Whitney U test and Fisher's exact test.

RESULTS

Immediately after the block, patients in group 1 reported significant pain relief compared with those in group 2 (P < 0.05), but long-term results did not differ between the groups. Mean analgesic consumption was lower in group 1. There were no deaths. Complications related to NCPB were transient diarrhoea and hypotension (P not significant between groups). Drug-related adverse effects were constipation (five of 12 patients in group 1 versus 12 of 12 in group 2), nausea and/or vomiting (four of 12 patients in group 1 versus 12 of 12 in group 2) (P < 0.05), one gastric ulcer and one gluteal abscess in group 2.

CONCLUSION

NCPB was associated with a reduction in analgesic drug administration and drug-related adverse effects, representing an effective tool in the treatment of pancreatic cancer pain.

Ondansetron versus metoclopramide in the treatment of postoperative nausea and vomiting

In this prospective, randomized, double-blind study, we compared the efficacy and safety of ondansetron and metoclopramide in the treatment of postoperative nausea and vomiting (PONV). One hundred seventy-five patients with PONV during recovery from anesthesia for gynecological laparoscopy were treated intravenously with either ondansetron 4 mg (58 patients), metoclopramide 10 mg (57 patients), or placebo (60 patients). Early antiemetic efficacy (abolition of vomiting within 10 min and of nausea within 30 min from the administration of the study drugs with no further vomiting or nausea episodes during the first hour) was obtained in 54 of 58 patients (93.1%) in the ondansetron group, in 38 of 57 patients (66.7%) in the metoclopramide group, and in 21 of 60 patients (35%) in the placebo group (P < 0.001). This difference was still significant when controlling for age, body weight, history of motion sickness, previous PONV episodes, duration of anesthesia, and intraoperative fentanyl consumption using a logistic model. Early antiemetic efficacy was inversely related to the amount of fentanyl administered during anesthesia, regardless of treatment. According to the Kaplan-Meier method, the probability of remaining PONV-free for 48 h after a successful treatment was 0.59 (95% confidence interval 0.45-0.71) in the ondansetron group, 0.45 (0.29-0.60) in the metoclopramide group, and 0.33 (0.15-0.53) in the placebo group (P = 0.003). In conclusion, ondansetron 4 mg is more effective than metoclopramide 10 mg and placebo in the treatment of established PONV.

[Prevention of postoperative nausea and vomiting with ondansetron: a prospective, randomized, double-blind study in 90 patients]

Postoperative nausea and vomiting (PONV) are among the most common complications in surgical patients. In this prospective, double blind, parallel group study we compare the prophylactic antiemetic efficacy of ondansetron versus placebo in 90 patients undergoing general balanced anaesthesia. The patients were stratified according to the kind of surgery and randomly allocated to three treatment groups: 30 patients (Group A) received ondansetron 4 mg i.v. 1 hour before the induction of anaesthesia and placebo 1 hour before the end of surgery; 30 patients (Group B) received placebo 1 hour before the end of anaesthesia and ondansetron 4 mg i.v. 1 hour before the end of surgery; 30 patients (Group C-control group) received placebo in both the administrations. Data were analyzed by Student t test and chi 2 test; significance was taken at p < 0.05. The three groups proved comparable with respect to demographic characteristics, duration of anaesthesia and fentanyl consumption. Analysis of the results showed that PONV had a significantly lower incidence in treated patients (Groups A and B) than in the control group patients (Group C): postoperative nausea occurred in 13%, 30% and 67% of patients in Group A, B and C respectively and it was associated with vomiting in 3%, 7% and 57% of patients in Group A, B and C respectively. Although the patients in Group A showed a lower incidence of PONV in comparison to the patients in Group B, such differences proved to be not statistically significant. No adverse effects in relation to drug administration were observed. We conclude that ondansetron 4 mg i.v. is safe and effective in preventing PONV in the surgical patients, particularly when administered before the induction of anaesthesia.

[Hemodynamic and metabolic impairment during hepatectomy: effect of continuous dobutamine infusion]

Following surgical liver resection haemodynamic and metabolic impairment, potentially responsible for post-operative hepatic failure may occur. In this prospective, randomized study such impairments and the effect on them of continuous peri-operative infusion of dobutamine were examined. Twelve patients, scheduled for hepatectomy, were divided in two groups: Group I was treated with an infusion of dobutamine 6 micrograms/kg/min from 10 minutes before the induction of anaesthesia till the fifth postoperative hour; Group II was considered as the control group. The main haemodynamic parameters, gastric pHi and serum lactate level were examined. No significant differences were detected in heart rate, parameters of pressure and SvO2. In both groups, during portal clamp, SVR increased while Cl and DO2 decreased with respect to basal and the other intra- and postoperative values. Gastric pHi decreased in both groups after portal clamp. These alterations were significantly lower in the group treated with dobutamine when compared with the control group. Serum lactate level increased in both groups. This increase was lower in Group I. Differences between groups were not statistically significant. In conclusion, during hepatectomy important haemodynamic and metabolic impairments occur. Dobutamine, by reducing such impairments, can be usefully employed in this kind of surgery.

[Is pain therapy just an ethical-behavioral problem?]

Pain is a subjective sensation caused not only by pathological events which trigger signals perceived as algogenic (sensory component), but also by emotional mechanisms and critical assessments which modify its perception, both quantitatively and qualitatively. Therefore pain is an unique and unrepeatable experience resulting from the interaction of these three components. When faced with a patient suffering pain, it is fundamental to establish the respective quantitative incidences of these three components, in order to define the correct therapy of the pain in its totality. Whereas there are numerous therapies for dealing with the sensory component, the same cannot be said of the emotional and critical elements. We therefore suggest a number of guidelines for tackling the problem and for developing therapeutic strategies. In the literature there are few perspective and randomized studies that may evaluate the real effectiveness of the different treatments; it follows that the tested and accepted by scientific community therapeutical protocols are very few. Only recently some studies that intend to evaluate the different therapeutical strategies in connection with the different algesic syndromes are being published in the most important scientific journals.

[Psychologic implications in loco-regional anesthesia]

A patients, who undergoes surgery, bears so stressful an emotional charge that his personality layout and life conflicts may emerge. When a patient is scheduled for loco-regional anaesthesia, the above mentioned issues should be taken into account to get a proper relation between the patient and the anaesthetist both in the pre- and intraoperative period. The following survey deals with psychological dynamics which compel the patient to ask for or reject a loco-regional anaesthetic procedure. Suggestions are also provided in order to manage adequately the anxiety and the hidden fears of the patient.

[Treatment of pain in advanced-stage intra-abdominal neoplasms]

Different types of pain are present in far advanced intra-abdominal cancer, sometimes in the same site too. An accurate semeiological analysis of pain is important because different types of pain often differently respond to the available therapeutical tools. In this paper the results and the complications of the most important methods of pain management in far advanced intra-abdominal cancer are examined. Analysis of the data reveals that the association of more methods, pharmacological and non, should be a rule rather than the exception.

[Pain control during the expulsion period in labor using bupivacaine and fentanyl]

The association of extremely diluted concentrations of opioids and local anesthetics appears to be highly promising for pain control during labour. This study examined the efficacy of the association of Fentanyl 100 mcg and Bupivacaine 10 mg in second-stage labour pain and perineal pain. The study which was carried out in 20 patients confirmed the lack of collateral effects on the fetus, mother (except for slight itching in 25% of cases) and the progress of labour. A virtually total elimination of pain was obtained in all cases during the dilatation and expulsion stages. During the second stage of labour pain was completely abolished in 50% of cases, whereas in the remaining 50% it lasted on average for 13 minutes. Perineal analgesia was sufficient to allow episiorrhaphy in 50% of patients without resorting to the use of local anesthetic.

Three posterior percutaneous celiac plexus block techniques. A prospective, randomized study in 61 patients with pancreatic cancer pain

Variations and refinements of the classic retrocrural technique of neurolytic celiac plexus block (NCPB) for pancreatic cancer pain (PCP) have been proposed over the last 30 yr to improve success rates, avoid complications and enhance diagnostic accuracy. The aim of this prospective, randomized study was to assess the efficacy and morbidity of three posterior percutaneous NCPB techniques in 61 patients with PCP. The 61 patients were randomly allocated to three NCPB treatment groups: group 1 (20 patients, transaortic plexus block); group 2 (20 patients, classic retrocrural block); and group 3 (21 patients, bilateral chemical splanchnicectomy). The quality and quantity of pain were analyzed before and after NCPB. No statistically significant differences (P greater than 0.05) were found among the three techniques in terms of either immediate or up-to-death results. Operative mortality was nil with the three techniques and morbidity negligible. NCPB abolished celiac PCP in 70-80% of patients immediately after the block and in 60-75% until death. Because celiac pain was only a component of PCP in all patients, especially in those with a longer time course until death: 1) abolition of such pain did not ensure high percentages of complete pain relief (immediate pain relief in 40-52%; pain relief until death in 10-24%); 2) NCPB was effective in controlling PCP in a higher percentage of cases if performed early after pain onset, when the pain was still only or mainly of celiac type and responded well to nonsteroidal antiinflammatory drug therapy; and 3) the probability of patients remaining completely pain-free diminished with increased survival time.(ABSTRACT TRUNCATED AT 250 WORDS)

[The analgesic treatment of the surgical patient]

An effective treatment of postoperative pain can achieve a better postop course especially in high risk patients. Pain is unacceptable when it can be relieved and, beside all it causes vasoconstriction, hypertension, tachycardia, fluid retention and pulmonary hypoventilation. A correct use of both narcotic drugs and NSAIDs are sufficient in most cases. In high risk patients, mainly after thoracic and upper abdominal procedures, insertion of a peridural catheter for drug administration can be very useful. The authors discuss the therapeutic possibilities according mainly to their experience.