Association between respiratory distress time and invasive mechanical ventilation in COVID-19 patients: A multicentre regional cohort study

AIM

To determine whether the duration of respiratory distress symptoms in severe COVID-19 pneumonia affects the need for invasive mechanical ventilation and clinical outcomes.

MATERIALS AND METHODS

An observational multicentre cohort study of patients hospitalised in five COVID-19-designated ICUs of the University Hospitals of Emilia-Romagna Region. Patients included were adults with pneumonia due to SARS-CoV-2 with PaO₂/FiO₂ ratio <300 mmHg, respiratory distress symptoms, and need for mechanical ventilation (invasive or non-invasive). Exclusion criteria were an uncertain time of respiratory distress, end-of-life decision, and mechanical respiratory support before hospital admission.

MEASUREMENTS AND MAIN RESULTS

We analysed 171 patients stratified into tertiles according to respiratory distress duration (distress time, DT) before application of mechanical ventilation support. The rate of patients requiring invasive mechanical ventilation was significantly different (p < 0.001) among the tertiles: 17/57 patients in the shortest duration, 29/57 in the intermediate duration, and 40/57 in the longest duration. The respiratory distress time significantly increased the risk of invasive ventilation in the univariate analysis (OR 5.5 [CI 2.48-12.35], p = 0.003). Multivariable regression analysis confirmed this association (OR 10.7 [CI 2.89-39.41], p < 0.001). Clinical outcomes (mortality and hospital stay) did not show significant differences between DT tertiles.

DISCUSSION

Albeit preliminary and retrospective, our data raised the hypothesis that the duration of respiratory distress symptoms may play a role in COVID-19 patients' need for invasive mechanical ventilation. Furthermore, our observations suggested that specific strategies may be directed towards identifying and managing early symptoms of respiratory distress, regardless of the levels of hypoxemia and the severity of the dyspnoea itself.

Supraspinal neuroinflammation and anxio-depressive-like behaviors in young- and older- adult mice with osteoarthritis pain: the effect of morphine

RATIONALE

Asteoarthritis (OA) is a leading cause of chronic pain in the elderly population and is often associated with emotional comorbidities such as anxiety and depression. Despite age is a risk factor for both OA and mood disorders, preclinical studies are mainly conducted in young adult animals.

OBJECTIVES

Here, using young adult (11-week-old) and older adult (20-month-old) mice, we evaluate in a monosodium-iodoacetate-(MIA)-induced OA model the development of anxio-depressive-like behaviors and whether brain neuroinflammation may underlie the observed changes. We also test whether an effective pain treatment may prevent behavioral and biochemical alterations.

METHODS

Mechanical allodynia was monitored throughout the experimental protocol, while at the end of protocol (14 days), anxio-depressive-like behaviors and cognitive dysfunction were assessed. Neuroinflammatory condition was evaluated in prefrontal cortex, hippocampus and hypothalamus. Serum IFNγ levels were also measured. Moreover, we test the efficacy of a 1-week treatment with morphine (2.5 mg/kg) on pain, mood alterations and neuroinflammation.

RESULTS

We observed that young adult and older adult controls (CTRs) mice had comparable allodynic thresholds and developed similar allodynia after MIA injection. Older adult CTRs were characterized by altered behavior in the tests used to assess the presence of depression and cognitive impairment and by elevated neuroinflammatory markers in brain areas compared to younger ones. The presence of pain induced depressive-like behavior and neuroinflammation in adult young mice, anxiety-like behavior in both age groups and worsened neuroinflammation in older adult mice. Morphine treatment counteracted pain, anxio-depressive behaviors and neuroinflammatory activation in both young adult and older adult mice.

CONCLUSIONS

Here, we demonstrated that the presence of chronic pain in young adult mice induces mood alterations and supraspinal biochemical changes and aggravates the alterations already evident in older adult animals. A treatment with morphine, counteracting the pain, prevents the development of anxio-depressive disorders and reduces neuroinflammation.

Wireless Peripheral Nerve Stimulation for The Upper Limb: A Case Report

Peripheral neuro-stimulation (PNS) has been proved to be effective for the treatment of neuropathic pain as well as other painful conditions. We discuss two approaches to PNS placement in the upper extremity. The first case describes a neuropathic syndrome after the traumatic amputation of the distal phalanx of the fifth digit secondary to a work accident with lack of responsiveness to a triple conservative therapy. An upper arm region approach for the PNS was chosen. The procedure had a favorable outcome; in fact, after one month the pain symptoms were absent (VAS 0) and the pharmacological therapy was suspended. The second case presented a patient affected by progressive CRPS type II in the sensory regions of the ulnar and median nerve in the hand, unresponsive to drug therapy. For this procedure, the PNS device was implanted in the forearm. Unfortunately, in this second case the migration of the catheter affected the effectiveness of the treatment. After examining the two cases in this paper, we changed our practice and suggest the implantation of PNS for radial, median and/or ulnar nerve stimulation in the upper arm region, which has significant advantages over the forearm region.

Osteoarthritis Pain in Old Mice Aggravates Neuroinflammation and Frailty: The Positive Effect of Morphine Treatment

Knee osteoarthritis is a common cause of pain and disability in old subjects. Pain may predispose to the development of frailty. Studies on mechanisms underlying pain in osteoarthritis models during aging are lacking. In this work, we used the monosodium iodoacetate model of osteoarthritis in adult (11-week-old) and old (20-month-old) C57BL/6J mice to compare hypersensitivity, locomotion, neuroinflammation, and the effects of morphine treatment. After osteoarthritis induction in adult and old mice, weight-bearing asymmetry, mechanical allodynia, and thermal hyperalgesia similarly developed, while locomotion and frailty were more affected in old than in adult animals. When behavioral deficits were present, the animals were treated for 7 days with morphine. This opioid counteracts the behavioral alterations and the frailty index worsening both in adult and old mice. To address the mechanisms that underlie pain, we evaluated neuroinflammatory markers and proinflammatory cytokine expression in the sciatic nerve, DRGs, and spinal cord. Overexpression of cytokines and glia markers were present in osteoarthritis adult and old mice, but the activation was qualitatively and quantitatively more evident in aged mice. Morphine was able to counteract neuroinflammation in both age groups. We demonstrate that old mice are more vulnerable to pain's detrimental effects, but prompt treatment is successful at mitigating these effects.

Artificial intelligence and anesthesia: a narrative review

Background and Objective

Methods

Key Content and Findings

Conclusions

Frailty and pain, human studies and animal models

The hypothesis that pain can predispose to frailty development has been recently investigated in several clinical studies suggesting that frailty and pain may share some mechanisms. Both pain and frailty represent important clinical and social problems and both lack a successful treatment. This circumstance is mainly due to the absence of in-depth knowledge of their pathological mechanisms. Evidence of shared pathways between frailty and pain are preliminary. Indeed, many clinical studies are observational and the impact of pain treatment, and relative pain-relief, on frailty onset and progression has never been investigated. Furthermore, preclinical research on this topic has yet to be performed. Specific researches on the pain-frailty relation are needed. In this narrative review, we will attempt to point out the most relevant findings present in both clinical and preclinical literature on the topic, with particular attention to genetics, epigenetics and inflammation, in order to underline the existing gaps and the potential future interventional strategies. The use of pain and frailty animal models discussed in this review might contribute to research in this area.

COVID-19 respiratory support outside the ICU's doors. An observational study for a new operative strategy

Background and aim:

During the first wave of the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) pandemic, we faced a massive clinical and organizational challenge having to manage critically ill patients outside the Intensive Care Unit (ICU). This was due to the significant imbalance between ICU bed availability and the number of patients presenting Acute Hypoxemic Respiratory Failure caused by SARS-CoV-2-related interstitial pneumonia. We therefore needed to perform Non-Invasive Ventilation (NIV) in non-intensive wards to assist these patients and relieve pressure on the ICUs and subsequently implemented a new organizational and clinical model. This study was aimed at evaluating its effectiveness and feasibility.

Methods:

We recorded the anamnestic, clinical and biochemical data of patients undergoing non-invasive mechanical ventilation while hospitalized in non-intensive CoronaVirus Disease 19 (COVID-19) wards. Data were registered on admission, during anesthesiologist counseling, and when NIV was started and suspended. We retrospectively registered the available results from routine arterial blood gas and laboratory analyses for each time point.

Results:

We retrospectively enrolled 231 patients. Based on our criteria, we identified 46 patients as NIV responders, representing 19.9% of the general study population and 29.3% of the patients that spent their entire hospital stay in non-ICU wards. Overall mortality was 56.2%, with no significant differences between patients in non-intensive wards (57.3%) and those later admitted to the ICU (54%).

Conclusions:

NIV is safe and manageable in an emergency situation and could become part of an integrated clinical and organizational model. (www.actabiomedica.it)

24-Month Effectiveness of Periduoscopic Adhesiolysis in Reducing the Use of Spinal Cord Stimulation in Patient With Chronic Lumbar Pain: A Possible Therapeutic Regimen?

Objectives

Epiduroscopy is a minimally invasive procedure that is used in pain therapy to treat lumbar and root pain that is resistant to medical and infiltrative therapies. The indications for periduroscopy are partly shared with those of spinal cord stimulation (SCS): failed back surgery syndrome (FBSS) and stenosis of the vertebral canal in particular. The costs and risks of periduroscopy are considerably lower than those of SCS. The purpose of this study is to evaluate the clinical and economic advantages of integrating periduroscopy as a step prior to SCS for patients with severe lumbar or radicular pain that is unresponsive to pharmacological and infiltrative treatments.

Materials and Methods

Patients were enrolled if they had FBSS and spinal stenosis with indications for SCS and accepted periduroscopy treatment before the possible SCS trial. Patients were followed up for 24 months with evaluations of clinical data on the day after the procedure and at one and 24 months. The pain trend, satisfaction with the periduroscopy procedure, and the incidence of SCS implants in the study period were analyzed.

Results

A total of 106 patients were enrolled. Immediately after the procedure and in the first month, the reduction of pain and the level of patient satisfaction were high, but they were drastically reduced at 24 months with a progressive reappearance of symptoms that substantially overlapped with the pre-surgery levels. At 24 months, 48% of the patients underwent a neurostimulation trial, and a significant percentage of them were able to avoid the implantation of an SCS.

Conclusions

Periduroscopy appears to be rational as a step prior to SCS in terms of the improvement of pain symptoms in the short term, the definitive results in a significant percentage of patients, and the significant economic savings for the health system.

Pain management during labor: use of intermittent drug delivery devices for improvement of obstetric and neonatal outcome and reduction of healthcare burden: A large non-inferiority randomized clinical trial

BACKGROUND

Automated continuous epidural administration of local anesthetics provides a more stable analgesic block with decreasing of healthcare staff compared to manual boluses administration (TOP-UP) but is associated to high rate of operative vaginal delivery. We hypothesized that the use of programmed intermittent automated boluses (PIEB) is able to provide a good quality of analgesia and decreasing of anesthesiologic workload without increasing the rate of instrumental vaginal birth in comparison with TOP-UP technique. Laboring nulliparous woman aged between 18 and 46 years were randomized to epidural analgesia with 0.0625% levobupivacaine and sufentanil administered by PIEB or by TOP-UP techniques. Primary outcome was instrumental vaginal delivery rate and secondary outcomes were quality of analgesia, total and time-related drugs doses used, motor block, newborn outcome, and anesthesiologic workload.

RESULTS

Six hundred twenty-nine were randomized, and 628 were included in the intention-to-treat analysis. The rate of instrumental vaginal delivery was similar in the PIEB and TOP-UP groups (13.2% vs 9.7%, OR 1.4 95% CI 0.8 to 2.5; p 0.21). There was no difference between groups regarding mode of delivery (cesarean section vs vaginal birth), newborn outcome, and motor block. Patients in the PIEB group received more total and time-related drugs doses and a better quality of analgesia. Anesthesiological workload was significantly reduced in the PIEB group.

CONCLUSIONS

Our study demonstrated that epidural anesthesia with programmed intermittent epidural boluses by an automated device provides an effective and safe management of labor analgesia with improvement of pain control and sparing of man workload compared to manual top-up protocols.

The "pandemic" increase in lung ultrasound use in response to Covid-19: can we complement computed tomography findings? A narrative review

Coronavirus disease of 2019 (COVID-19) is a highly infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has rapidly spread to a global pandemic in March 2020. This emergency condition has been putting a severe strain on healthcare systems worldwide, and a prompt, dynamic response is instrumental in its management. While a definite diagnosis is based on microbiological evidence, the relationship between lung ultrasound (LU) and high-resolution computed tomography (HRCT) in the diagnosis and management of COVID-19 is less clear. Lung ultrasound is a point-of-care imaging tool that proved to be useful in the identification and severity assessment of different pulmonary conditions, particularly in the setting of emergency and critical care patients in intensive care units; HRCT of the thorax is regarded as the mainstay of imaging evaluation of lung disorders, enabling characterization and quantification of pulmonary involvement. Aims of this review are to describe LU and chest HRCT main imaging features of COVID-19 pneumonia, and to provide state-of-the-art insights regarding the integrated role of these techniques in the clinical decision-making process of patients affected by this infectious disease.

Lung Ultrasound in COVID-19 Pneumonia: Correlations with Chest CT on Hospital admission

Background

Lung ultrasound (LUS) is an accurate, safe, and cheap tool assisting in the diagnosis of several acute respiratory diseases. The diagnostic value of LUS in the workup of coronavirus disease-19 (COVID-19) in the hospital setting is still uncertain.

Objectives

The aim of this observational study was to explore correlations of the LUS appearance of COVID-19-related pneumonia with CT findings.

Methods

Twenty-six patients (14 males, age 64 ± 16 years) urgently hospitalized for COVID-19 pneumonia, who underwent chest CT and bedside LUS on the day of admission, were enrolled in this observational study. CT images were reviewed by expert chest radiologists, who calculated a visual CT score based on extension and distribution of ground-glass opacities and consolidations. LUS was performed by clinicians with certified competency in thoracic ultrasonography, blind to CT findings, following a systematic approach recommended by ultrasound guidelines. LUS score was calculated according to presence, distribution, and severity of abnormalities.

Results

All participants had CT findings suggestive of bilateral COVID-19 pneumonia, with an average visual scoring of 43 ± 24%. LUS identified 4 different possible ­abnormalities, with bilateral distribution (average LUS score 15 ± 5): focal areas of nonconfluent B lines, diffuse confluent B lines, small subpleural microconsolidations with pleural line irregularities, and large parenchymal consolidations with air bronchograms. LUS score was significantly correlated with CT visual scoring (r = 0.65, p < 0.001) and oxygen saturation in room air (r = −0.66, p < 0.001).

Conclusion

When integrated with clinical data, LUS could represent a valid diagnostic aid in patients with suspect COVID-19 pneumonia, which reflects CT findings.

Oncologic outcome, side effects and comorbidity of high-intensity focused ultrasound (HIFU) for localized prostate cancer. A review

Introduction

Prostate cancer is considered one of the most important health problems. Due to the increased number of diagnosed patients and the inability to distinguish aggressive tumors, minimally-invasive procedures have become increasingly interesting. High-intensity focused ultrasound (HIFU) is an alternative option to radical surgery to treat prostate cancer. To date, however, data on side effects and comorbidities of this technique are still not conclusive.

Methods and results

We reviewed the literature to concentrate on side effects and comorbidities of HIFU treatment of prostate cancer with the following key words: hifu, high intensity focused ultrasound, ultrasonic therapy, transrectal hifu, prostate ablation, side effects, comorbidities. MedLine and Embase via Ovid database were searched. Selection criteria were: English language, articles published between 2001 and 2015, case series including at least 100 participants and reported data on side effects and comorbidities. Sixteen uncontrolled studies were identified. No randomized controlled trials (RCT) were found in the literature comparing side effects and comorbidities of HIFU to other routine approaches to prostate cancer treatment.

Conclusion

HIFU seems to be a promising minimally-invasive treatment for low- and intermediate-risk prostate cancer, especially for patients who are unfit for radical surgery. Prospective studies with longer follow-up periods and RCT are required to properly assess the impact of side effects and comobidities related to the HIFU technique in comparison with other therapies to treat prostate cancer.

•

HIFU is a promising minimally-invasive treatment for prostate cancer, especially in patients with low- and intermediate-risk disease.

•

To date, the most proper indication to HIFU is for patients who are not fit for, or are unwilling to undergo, radical surgery.

•

The most common complications are impotence, urinary incontinence, acute urinary retention and urethral fistula.

•

High-intensity focused ultrasound is a safe and effective procedure.

Point-of-Care Chest Ultrasonography as a Diagnostic Resource for COVID-19 Outbreak in Nursing Homes

Objective

Bedside chest ultrasonography, when integrated with clinical data, is an accurate tool for improving the diagnostic process of many respiratory diseases. This study aims to evaluate the feasibility of a chest ultrasonographic screening program in nursing homes for detecting coronavirus disease-19 (COVID-19)–related pneumonia and improving the appropriateness of hospital referral of residents.

Design

Pragmatic, descriptive, feasibility study from April 2 to April 9, 2020.

Setting and Participants

A total of 83 older residents (age 85 ± 8) presenting mild to moderate respiratory symptoms and not previously tested for COVID-19, residing in 5 nursing homes in Northern Italy.

Methods

Chest ultrasonography was performed at the bedside by a team of hospital specialists with certified expertise in thoracic ultrasonography, following a systematic approach exploring 4 different areas for each hemithorax, from the anterior and posterior side. Presence of ultrasonographic signs of interstitial pneumonia, including comet-tail artifacts (B-lines) with focal or diffuse distribution, subpleural consolidations, and pleural line indentation, was detected. The specialist team integrated ultrasonography data with clinical and anamnestic information, and gave personalized therapeutic advice for each patient, including hospital referral when needed.

Results

The most frequent reasons for ultrasonographic evaluation were fever (63% of participants) and mild dyspnea (40%). Fifty-six patients (67%) had abnormal ultrasonographic findings. The most common patterns were presence of multiple subpleural consolidations (32 patients) and diffuse B-lines (24 patients), with bilateral involvement. A diagnosis of suspect COVID-19 pneumonia was made in 44 patients, and 6 of them required hospitalization. Twelve patients had ultrasonographic patterns suggesting other respiratory diseases, and 2 patients with normal ultrasonographic findings were diagnosed with COPD exacerbation.

Conclusions and Implications

In nursing home residents, screening of COVID-19 pneumonia with bedside chest ultrasonography is feasible and may represent a valid diagnostic aid for an early detection of COVID-19 outbreaks and adequate patient management.

Multidisciplinary management of a large pheochromocytoma presenting with cardiogenic shock: a case report

BACKGROUND

Pheochromocytoma is well-known for sudden initial presentations, particularly in younger patients. Hemodynamic instability may cause serious complications and delay a patient's ability to undergo surgical resection. Larger tumors present a further challenge because of the risk of catecholamine release during manipulations. In the case we present, increases in systemic vascular resistance caused cardiogenic shock, and the size of the lesion prompted surgeons to veer off from their usual approach.

CASE PRESENTATION

A 38-year-old female patient was admitted to our intensive care unit with hypertension and later cardiogenic shock. Profound systolic dysfunction (left ventricular ejection fraction of 0.12) was noted together with severely increased systemic vascular resistance, and gradually responded to vasodilator infusion. A left-sided 11-cm adrenal mass was found with computed tomography and confirmed a pheochromocytoma with a meta-iodo-benzyl-guanidine scintigraphy. Surgical treatment was carefully planned by the endocrinologist, anesthesiologist and surgeon, and was ultimately successful. After prolonged hemodynamic stabilization, open adrenalectomy and nephrectomy were deemed safer because of lesion size and the apparent invasion of the kidney. Surgery was successful and the patient was discharged home 5 days after surgery. She is free from disease at almost 2 years from the initial event.

CONCLUSIONS

Large, invasive pheochromocytoma can be safely and effectively managed with open resection in experienced hands, provided all efforts are made to achieve hemodynamic stabilization and to minimize. Catecholamine release before and during surgery.

X(-rays) sometimes mark the spot: A case of occult central venous catheter embolization

INTRODUCTION

Breakage and fragment embolization is a rare but feared complication of peripherally inserted central catheter use. While chest radiographs are no longer the gold standard for determining peripherally inserted central catheter tip position, their use in diagnosing complications is still warranted. We report a case of occult catheter embolization discovered by routine chest X-ray.

CASE DESCRIPTION

A patient with a right brachial vein peripherally inserted central catheter was admitted to our Emergency Department for palpitations and dyspnea. The peripherally inserted central catheter was not visible at presentation, and she was unclear as to what had happened; she left the Emergency Department before workup was performed. Catheter embolization was discovered upon implantation of a new peripherally inserted central catheter.

CONCLUSION

Although routine chest radiographs are no longer necessary after peripherally inserted central catheter implantation, they are in diagnosing peripherally inserted central catheter-related complications even in asymptomatic patients. We discuss their use and the possible role of securement devices in preventing some instances of catheter embolization.

If it looks like a catheter and winds like a catheter . . . fibroblastic sheath mimicking a central venous catheter fragment: A case report

INTRODUCTION

Fibroblastic sheath formation is a well-known complication of long-term central venous catheters. When calcified, fibroblastic (formerly known as "fibrin") sheaths may be easily mistaken for retained catheter fragments. We describe one such case and how imaging was used to recognize the sheath and avoid unnecessary interventions.

CASE DESCRIPTION

A patient with systemic sclerosis was referred for port removal because of suspected infection. A later computed tomography scan showed a persistent tubular structure coursing behind the right clavicle, which was also seen in an anteroposterior chest radiograph. Three-dimensional reconstruction and analysis of the structure's lumen in comparison to previous imaging studies allowed us to confirm that it was, in fact, a calcified fibroblastic sheath. The patient's course was uneventful thereafter.

CONCLUSION

Three-dimensional computed tomography reconstruction, as well as the hollow appearance of a tubular structure after removal of a central catheter may help differentiate a fibroblastic sheath from a retained catheter fragment. Accurate surgical notes mentioning the length of the catheter at implant and explant are also of paramount importance.

Fibromyalgia: Genetics and epigenetics insights may provide the basis for the development of diagnostic biomarkers

Fibromyalgia is a disease characterized by chronic widespread pain with additional symptoms, such as joint stiffness, fatigue, sleep disturbance, cognitive dysfunction, and depression. Currently, fibromyalgia diagnosis is based exclusively on a comprehensive clinical assessment, according to 2016 ACR criteria, but validated biological biomarkers associated with fibromyalgia have not yet been identified. Genome-wide association studies investigated genes potentially involved in fibromyalgia pathogenesis highlighting that genetic factors are possibly responsible for up to 50% of the disease susceptibility. Potential candidate genes found associated to fibromyalgia are SLC64A4, TRPV2, MYT1L, and NRXN3. Furthermore, a gene-environmental interaction has been proposed as triggering mechanism, through epigenetic alterations: In particular, fibromyalgia appears to be characterized by a hypomethylated DNA pattern, in genes implicated in stress response, DNA repair, autonomic system response, and subcortical neuronal abnormalities. Differences in the genome-wide expression profile of microRNAs were found among multiple tissues, indicating the involvement of distinct processes in fibromyalgia pathogenesis. Further studies should be dedicated to strength these preliminary findings, in larger multicenter cohorts, to identify reliable directions for biomarker research and clinical practice.

Complication of epiduroscopy: a brief review and case report

Epiduroscopy is defined as a percutaneous, minimally invasive endoscopic investigation of the epidural space. Periduroscopy is currently used mainly as a diagnostic tool to directly visualize epidural adhesions in patients with failed back surgery syndrome (FBSS), and as a therapeutic action in patients with low back pain by accurately administering drugs, releasing inflammation, washing the epidural space, and mechanically releasing the scars displayed. Considering epiduroscopy a minimally invasive technique should not lead to underestimating its potential complications. The purpose of this review is to summarize and explain the mechanisms of the side effects strictly related to the technique itself, leaving aside complications considered typical for any kind of extradural procedure (e.g. adverse reactions due to the administration of drugs or bleeding) and not fitting the usual concept of epiduroscopy for which the data on its real usefulness are still lacking. The most frequent complications and side effects of epiduroscopy can be summarized as non-persistent post-procedural low back and/or leg discomfort/pain, transient neurological symptoms (headache, hearing impairment, paresthesia), dural puncture with or without post dural puncture headache (PDPH), post-procedural visual impairment with retinal hemorrhage, encephalopathy resulting in rhabdomyolysis due to a dural tear, intradural cyst, as well as neurogenic bladder and seizures. We also report for first time, to our knowledge, a case of symptomatic pneumocephalus after epiduroscopy, and try to explain the reason for this event and the precautions to avoid this complication.

Sex differences in the daily rhythmicity of morphine consumption after major abdominal surgery

OBJECTIVE

The sex of the patients has been shown to affect postoperative pain and morphine consumption; still a clear understanding able to explain the reasons behind this difference struggles to emerge. Our research aimed to investigate one specific aspect of the variability in morphine consumption between sexes. Previous studies have shown that circadian rhythm can influence opioid consumption. Furthermore, circadian rhythm is different between female and male. Our analysis investigated the presence of differences in daily rhythmicity of morphine consumption between males and females.

DESIGN

This is a secondary analysis of data collected during 2 years long multicenter clinical trial (NCT01233752).

SETTINGS

Clinical data were collected in two Italian hospitals: IRCCS Foundation Policlinico S. Matteo (Pavia) and San Gerardo Hospital (Monza).

PATIENTS

The authors recorded data about morphine consumption in 157 patients who underwent major abdominal surgery, who received morphine intravenous patient-controlled analgesia (IV-PCA) as postoperative analgesia.

INTERVENTIONS

The authors analyzed the daily periodicity of effective boluses delivered by morphine IV-PCA with Poisson multilevel models, adjusted by the time of start for each pump. An effective bolus was defined as a correctly delivered bolus of 1 mg of morphine. The authors also evaluated the interactions among the time of the day and sex, age (</≥55 y), and body mass index (BMI;</≥30 kg/m²).

MAIN OUTCOME MEASURE(S)

Differences in sex of morphine consumption rhythms over the 24 hours of the day.

RESULTS

Morphine consumption showed a statistically significant daily periodicity (p < 0.001) in our study population. Consumption was higher around 2 AM (rate 0.4 mg/min·patient) and lower around 12 PM (rate 0.05 mg/min·patient). Global consumption was not associated with the pump start time, age, or sex. The daily periodicity of morphine consumption was different between males and females (p = 0.004), with males consuming more morphine during the night.

CONCLUSIONS

Our analysis confirmed the presence of daily rhythm for morphine consumption in patients treated with IV-PCA morphine after major abdominal surgery. A difference in the daily periodicity was observed between sexes. No difference emerged in daily periodicity for the categories of age and BMI.

Changes in total plasma and serum N-glycome composition and patient-controlled analgesia after major abdominal surgery

Systemic inflammation participates to the complex healing process occurring after major surgery, thus directly affecting the surgical outcome and patient recovery. Total plasma N-glycome might be an indicator of inflammation after major surgery, as well as an anti-inflammatory therapy response marker, since protein glycosylation plays an essential role in the inflammatory cascade. Therefore, we assessed the effects of surgery on the total plasma N-glycome and the association with self-administration of postoperative morphine in two cohorts of patients that underwent major abdominal surgery. We found that plasma N-glycome undergoes significant changes one day after surgery and intensifies one day later, thus indicating a systemic physiological response. In particular, we observed the increase of bisialylated biantennary glycan, A2G2S[3,6]2, 12 hours after surgery, which progressively increased until 48 postoperative hours. Most changes occurred 24 hours after surgery with the decrease of most core-fucosylated biantennary structures, as well as the increase in sialylated tetraantennary and FA3G3S[3,3,3]3 structures. Moreover, we observed a progressive increase of sialylated triantennary and tetraantennary structures two days after surgery, with a concomitant decrease of the structures containing bisecting N-acetylglucosamine along with bi- and trisialylated triantennary glycans. We did not find any statistically significant association between morphine consumption and plasma N-glycome.

Mechanisms of low back pain: a guide for diagnosis and therapy

Chronic low back pain (CLBP) is a chronic pain syndrome in the lower back region, lasting for at least 3 months. CLBP represents the second leading cause of disability worldwide being a major welfare and economic problem. The prevalence of CLBP in adults has increased more than 100% in the last decade and continues to increase dramatically in the aging population, affecting both men and women in all ethnic groups, with a significant impact on functional capacity and occupational activities. It can also be influenced by psychological factors, such as stress, depression and/or anxiety. Given this complexity, the diagnostic evaluation of patients with CLBP can be very challenging and requires complex clinical decision-making. Answering the question "what is the pain generator" among the several structures potentially involved in CLBP is a key factor in the management of these patients, since a mis-diagnosis can generate therapeutical mistakes. Traditionally, the notion that the etiology of 80% to 90% of LBP cases is unknown has been mistaken perpetuated across decades. In most cases, low back pain can be attributed to specific pain generator, with its own characteristics and with different therapeutical opportunity. Here we discuss about radicular pain, facet Joint pain, sacro-iliac pain, pain related to lumbar stenosis, discogenic pain. Our article aims to offer to the clinicians a simple guidance to identify pain generators in a safer and faster way, relying a correct diagnosis and further therapeutical approach.

Mechanisms of low back pain: a guide for diagnosis and therapy

Chronic low back pain (CLBP) is a chronic pain syndrome in the lower back region, lasting for at least 3 months. CLBP represents the second leading cause of disability worldwide being a major welfare and economic problem. The prevalence of CLBP in adults has increased more than 100% in the last decade and continues to increase dramatically in the aging population, affecting both men and women in all ethnic groups, with a significant impact on functional capacity and occupational activities. It can also be influenced by psychological factors, such as stress, depression and/or anxiety. Given this complexity, the diagnostic evaluation of patients with CLBP can be very challenging and requires complex clinical decision-making. Answering the question "what is the pain generator" among the several structures potentially involved in CLBP is a key factor in the management of these patients, since a mis-diagnosis can generate therapeutical mistakes. Traditionally, the notion that the etiology of 80% to 90% of LBP cases is unknown has been mistaken perpetuated across decades. In most cases, low back pain can be attributed to specific pain generator, with its own characteristics and with different therapeutical opportunity. Here we discuss about radicular pain, facet Joint pain, sacro-iliac pain, pain related to lumbar stenosis, discogenic pain. Our article aims to offer to the clinicians a simple guidance to identify pain generators in a safer and faster way, relying a correct diagnosis and further therapeutical approach.

Continuous wound infusion of local anesthetic and steroid after major abdominal surgery: study protocol for a randomized controlled trial

Background

Inflammatory response is one of the key components of pain perception. Continuous infusion (CWI) of local anesthetics has been shown to be effective in controlling pain and reducing postoperative morphine consumption, but the effect of adding a potent anti-inflammatory drug (such as a steroid) has never been addressed. In our study, we want to investigate the effect of CWI with local anesthetic + methylprednisolone on acute and persistent pain, correlating clinical data with biomarkers of inflammation and genetic background.

Methods/Design

After approval by their institutional review board, three hospitals will enroll 120 patients undergoing major abdominal surgery in a randomized, double-blind, phase III study. After a 24-h CWI of ropivacaine 0.2 % + methylprednisolone 1 mg/kg, patients will be randomly assigned to receive either ropivacaine + steroid or placebo for the next 24 h. Then, patient-controlled CWI with only ropivacaine 0.2 % or placebo (according to the group of randomization) is planned after 48 h up to 7 days (bolus 10 ml, lock-out 1 h, maximum dose of 40 ml in 4 h). Morphine equivalent consumption up to 7 days will be analyzed, together with any catheter- or drug-related side effect. Persistent post-surgical pain (PPSP) incidence will also be investigated. Our primary endpoint is analgesic consumption in the first 7 days after surgery; we will evaluate, as secondary endpoints, any catheter- or drug-related side effect, genotype/phenotype correlations between some polymorphisms and postoperative outcome in terms of morphine consumption, development of the inflammatory response, and incidence of PPSP. Finally, we will collect, in a subgroup of patients, wound exudate samples by micro-dialysis, blood samples, and urine samples up to 72 h to investigate local and systemic inflammation and oxidative stress.

Discussion

This is a phase III trial to evaluate the safety and efficacy of wound infusion with steroid and local anesthetic. The study is aimed also to evaluate how long this infusion has to be maintained in order to maximize effectiveness. Our data are intended to quantify the amount of ropivacaine and methylprednisolone needed by patients undergoing major abdominal surgery, to be stored in a new nanotechnology device for sustained pain treatment after surgery. We also aim to clarify the roles of inflammatory response, oxidative stress, and genetic background on postoperative and persistent pain after major abdominal surgery.

Trial registration

The trial was registered on ClinicalTrials.gov (NCT02002663) on 24 Oct. 2013.

The learning curve for laryngoscopy: Airtraq versus Macintosh laryngoscopes

PURPOSE

Airtraq use by inexperienced personnel has been evaluated in simulator studies, but little is known about the learning process in real patients. This prospective study was designed to compare learning curves for laryngoscopy with the Airtraq or Macintosh laryngoscopes in patients under general anesthesia.

METHODS

Ten medical students with no prior experience in airway management were recruited on a voluntary basis and underwent training in Macintosh and Airtraq laryngoscopy. Patients with no difficult intubation criteria were enrolled after consent. Each student performed laryngoscopy with either device on ten consecutive patients. Success was defined as Cormack-Lehane grading ≤2. We also recorded subjective difficulty scores on an 11-point numerical rating scale. Learning curves were drawn using cumulative success rates and 95% confidence intervals calculated with bootstrap procedures.

RESULTS

The mean (95% CI) success rates for the procedures were 86.0% (76.7-93.3%) for the Airtraq and 64.0% (52.0-75.0%) for the Macintosh laryngoscope. Differences in success rate were significant from the fourth attempt and were 22.0% (8.2-36.5%) after the tenth. Seven students achieved success rates ≥90% using the Airtraq, versus one using the Macintosh (P = 0.022). Median (25th-75th percentile) difficulty scores were 2 (1-4) and 4 (2-6), respectively (P < 0.001).

CONCLUSION

Students achieved higher success rates using the Airtraq laryngoscope during early training on live patients. The Airtraq may be a useful choice for teaching advanced airway management, especially to professionals who will not perform laryngoscopy on a regular basis.

Intrathecal atropine to prevent postoperative nausea and vomiting after Cesarean section: a randomized, controlled trial

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common adverse effect of intrathecal morphine, especially after Cesarean section. This randomized controlled trial investigated the effects of intrathecal administration of a small-dose of atropine on postoperative nausea and vomiting after Cesarean section.

METHODS

Parturients with ASA physical status class I-II scheduled for elective Cesarean section and consenting to spinal anesthesia were enrolled. They received 0.5% hyperbaric bupivacaine 12.5 mg, morphine 200 µg and one of the following three solutions: atropine 100 µg intrathecally and saline intravenously; saline intrathecally and atropine 100 µg intravenously; saline only both intravenously and intrathecally. We examined the incidence and severity of PONV, pain ratings and the need for analgesics.

RESULTS

We followed 204 parturients. The incidence of PONV was 15%, 37% and 49% in the three groups, respectively (P<0.001). The relative risk reduction for PONV when using intrathecal atropine was 69% vs. placebo and 59% vs. intravenous atropine. No differences were noted in terms of postoperative pain.

CONCLUSION

Intrathecal atropine had a significant antiemetic effect, making it a useful adjunct for intrathecal opioid-related PONV.

Anesthesia and postoperative analgesia after intra-articular injection of warmed versus room-temperature levobupivacaine: a double-blind randomized trial

PURPOSE

This prospective, randomized, blinded study was designed to compare the effects of warmed versus room-temperature levobupivacaine in patients undergoing knee arthroscopy and partial meniscectomy.

METHODS

Patients were randomly allocated into 2 groups of 16 patients each. In all patients the 2 portal sites were infiltrated with 10 mL of room-temperature mepivacaine (20 mg/mL). In the first group, patients underwent intra-articular injection of 20 mL of levobupivacaine (5 mg/mL) and 0.005-mg/mL epinephrine (1:200,000) at a temperature of 40 degrees C +/- 0.2 degrees C, whereas in the second group the levobupivacaine and epinephrine were at room temperature (25 degrees C +/- 0.5 degrees C). Pain was graded and recorded intraoperatively and postoperatively by use of a visual analog scale (VAS). Analgesia was supplemented if the VAS score was 4 cm or greater with morphine intraoperatively or ketorolac postoperatively.

RESULTS

There were no significant differences between groups in intraoperative and postoperative VAS values. There was no need for morphine as a rescue dose in any patient during surgery. Eight patients treated with warmed levobupivacaine and seven patients treated with room-temperature levobupivacaine requested a single rescue dose of ketorolac (30 mg) postoperatively.

CONCLUSIONS

No compelling evidence exists to suggest that intra-articular injection of warmed levobupivacaine is more effective than room-temperature levobupivacaine for intraoperative anesthesia and postoperative analgesia in patients undergoing partial meniscectomy during knee arthroscopy.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Systemic hemodynamic effects of sequential pneumatic compression of the lower limbs: a prospective study in healthy volunteers

STUDY OBJECTIVE

To evaluate the effects on systemic hemodynamics of sequential pneumatic compression of the lower limbs in healthy volunteers.

DESIGN

Prospective, self-controlled, volunteer study.

SETTING

University teaching hospital.

PATIENTS

11 healthy volunteers, aged 25 +/- 1.3 years.

INTERVENTIONS AND MEASUREMENTS

After volunteers underwent a 6-hour period of fasting and 15 minutes of rest in the supine position, baseline systemic hemodynamics were assessed using transthoracic electrical bioimpedance. Peripheral venous pressure was measured using a 16-gauge intravenous cannula inserted in the forearm and connected to a pressure monitor. Then sequential pneumatic compression of the lower limbs was activated for a 30-minute period, and systemic hemodynamic measurements were repeated. In each volunteer, measurements were repeated twice in two consecutive days, and average values were calculated for each volunteer.

MAIN RESULTS

After activation of sequential pneumatic compression of the lower limbs, mean arterial blood pressure increased from 90 mmHg (79-107 mmHg) to 95 mmHg (79-129 mmHg) (P = 0.02), whereas heart rate decreased from 79 bpm (51-94 bpm) to 75 bpm (53-90 bpm) (P = 0.02). This was associated with a significant increase in peripheral vascular resistance index (from 545 [440-1066] to 613 [369-1280] dynes s cm(-5) m(-2) [P = 0.013]) and reduction in cardiac index (from 3.4 [2.7- 4.5] to 3.2 [2.5-4.0] L/min per m2 [P = 0.034]).

CONCLUSIONS

The application of sequential pneumatic compression to the lower limbs is associated with minor increases in mean arterial blood pressure, with moderate reduction of cardiac output and heart rate.

Intrathecal ropivacaine 5 mg/ml for outpatient knee arthroscopy: a comparison with lidocaine 10 mg/ml

PURPOSE

The aim of this prospective, randomised, blind study was to compare the evolution of spinal block produced with 50 mg lidocaine 10 mg/ml and 10 mg ropivacaine 5 mg/ml for outpatient knee arthroscopy.

METHODS

Thirty outpatients undergoing knee arthroscopy received 50 mg of lidocaine 10 mg/ml (n=15) or 10 mg of ropivacaine 5 mg/ml (n=15) intrathecally. The evolution of spinal block was recorded until home discharge, while the occurrence of transient neurologic symptoms (TNS) was evaluated through phone-call follow-ups.

RESULTS

The median onset time was 15 (10-21) min with lidocaine and 24 (11-37) min with ropivacaine (P=0.109). Spinal lidocaine resulted in a faster resolution of sensory block [148 (130-167) min vs. 188 (146-231) (P=0.022)], unassisted ambulation with crutches [176 (144-208) min vs. 240 (179-302) min (P=0.014)], and voiding [208 (163-254) min vs. 293 (242-343) min (P=0.001)] than ropivacaine. Recovery of motor function required 113 (95-131) min with lidocaine and 135 (87-183) with ropivacaine (P=0.219). Six lidocaine patients reported TNS (40%) as compared with no patient receiving ropivacaine (0%) (P=0.005).

CONCLUSIONS

Spinal block produced with 10 mg ropivacaine 5 mg/ml is as effective as that produced by 50 mg of lidocaine 10 mg/ml. Recovery of unassisted ambulation and spontaneous voiding occurred earlier with lidocaine, but this was associated with a markedly higher incidence of TNS.

Updating postoperative pain management: from multimodal to context-sensitive treatment

Although a wealth of evidence exists on effective postoperative pain (POP) treatment, surgical patients still suffer from inadequate analgesic regimens, and outcomes have been shown to improve only within the context of tightly controlled, randomized trials. The pathophysiology of pain seems to suggest that analgesic regimens aimed at inhibition of neurotransmission and neuroplastic phenomena should be instituted immediately before the painful stimuli are applied. Several protocols have been proposed, but the final choice should be made according to patients' needs, surgical indications, and institutional resources. Optimal POP management may succeed in improving outcomes only when combined with hospital-wide protocols for early rehabilitation and recovery; in the absence of adequate monitoring, equipment, motivation and coordination, even state-of-the-art techniques may fail to show results in terms of returning to daily life. Analgesic efficacy should always be balanced against safety and the ability to monitor patients in order to reduce complications that may actually impair recovery. A ''context-sensitive'' approach to POP, therefore, is suggested. Context-sensitive analgesia should be instituted as early as deemed necessary to avoid persistent pain, and it should be continued, with different modalities, until full recovery from surgery. In this way, it should constitute a ''bridge'' therapy from surgery to full healing. The use of neuroprotective agents to reduce the risk of postoperative hyperalgesia and other sensory disturbances should be considered in the context of specific surgical interventions.

Transcutaneous carbon dioxide monitoring in spontaneously breathing, nonintubated patients in the early postoperative period

BACKGROUND

The authors investigated the accuracy of transcutaneous capnometry (TcPCO(2)) in estimating arterial blood carbon dioxide partial pressure (PaCO(2)) during spontaneous breathing in patients admitted to our surgical intensive care unit (ICU).

METHODS

Serial TcPCO(2) and PaCO(2) measurements were taken in stable patients undergoing postoperative monitoring after major abdominal, vascular, or thoracic surgery. Patients were enrolled 12 hours after extubation. Exclusion criteria were pulmonary dysfunction, hemodynamic instability, or anemia. Linear regression, mixed models, and Bland-Altman analyses were used to compare accuracy and correlation between the two variables. Data are presented as means (95% confidence intervals).

RESULTS

PaCO(2) values ranged between 26 mmHg and 52 mmHg. Mean values for TcPCO(2) and PaCO(2) were 35.3 (33.8-36.8) mmHg and 39.2 (37.6-40.7) (P<0.001). Bland-Altman analysis showed a bias of -3.8 (-5.1-2.5) mmHg with upper and lower limits of agreement of 5.6 (3.4-7.9) mmHg and -13.3 (-15.6 -11.1) mmHg, respectively. Thirty-one (55.4%) measurements disagreed by 3 mmHg or more. Linear mixed model analysis with adjustment for repeated measurements showed low correlation (r=0.63; P<0.0005). There were small but significant differences between patients in the correlation coefficient (P=0.04).

CONCLUSION

TcPCO(2) showed moderate bias with wide limits of agreement when compared to PaCO(2) in our patients. The regression model showed low correlation of the measurements when adjusting for repeated measurements and between-subject variances. TcPCO(2) may not provide an accurate quantitative estimation of PaCO(2) in stable, spontaneously breathing, nonintubated patients in the early postoperative period.

Forehead reflectance oximetry: a clinical comparison with conventional digit sensors during laparotomic and laparoscopic abdominal surgery

OBJECTIVE

This study compared the performance of forehead reflectance and conventional pulse oximetry (SpO(2)) in mechanically ventilated, anesthetized patients undergoing major abdominal surgery with either laparoscopic or laparotomic techniques.

METHODS

SpO(2) was continuously measured both with a forehead reflectance and a conventional digit sensor in 20 ASA physical status I-III, anesthetized patients undergoing either a laparotomic (group Laparotomy, n = 10) or laparoscopic (group Laparoscopy, n = 10) major abdominal surgery. SpO(2) values measured with the two sensors were continuously recorded at 10-second intervals during the entire procedure, and then analyzed for consistency.

RESULTS

In group Laparotomy finger and forehead readings remained consistently similar during the study period; on the contrary, in group Laparoscopy forehead SpO(2) readings showed a much wider variability. The mean (95% Confidence Intervals) difference between finger and forehead SpO(2) readings was 2.0% (-1.3% to +6.0%) in group Laparotomy and 2.5% (-3.5% to +8.4%) in group Laparoscopy (p = 0.001); however, in group Laparoscopy the mean difference between digit and forehead SpO(2) values increased from 0.2% (CI(95): -2.1% to +2.5%) during the first hour to 4.5% (CI(95): -2.5% to +11-5%) in the second hour (p = 0.0005), and 3.1% (CI(95): -2.4% to + 8.6%) in the third hour of surgery (p = 0.0005). Clinically relevant desaturation (decrease of SpO(2) < 89% for > or =30 s) detected with the forehead sensor in the Laparoscopy group was significantly more frequent and longer lasting than with conventional digit sensor. No differences were observed in group Laparotomy.

CONCLUSIONS

Forehead reflectance oximetry is as accurate as conventional digit based oximetry in mechanically ventilated patients undergoing laparotomic surgery in the supine position, but is significantly influenced by patient positioning and pneumoperitoneum during laparoscopic surgery.

Effects of ultrasound guidance on the minimum effective anaesthetic volume required to block the femoral nerve

BACKGROUND

We tested the hypothesis that ultrasound guidance may reduce the minimum effective anaesthetic volume (MEAV50) of ropivacaine 0.5% required to block the femoral nerve compared with nerve stimulation guidance.

METHODS

After standard premedication and sciatic nerve block were given, 60 patients undergoing knee arthroscopy were randomly allocated to receive a femoral nerve block with ropivacaine 0.5% using either nerve stimulation (group NS, n = 30) or ultrasound (group US, n = 30) guidance. The volume of the injected solution was varied for consecutive patients based on an up-and-down staircase method according to the response of the previous patient. The initial volume was 12 ml. A double-blinded observer evaluated the occurrence of complete loss of pinprick sensation in the femoral nerve distribution, with concomitant block of the quadriceps muscle: positive or negative responses within 30 min after the injection determined a 3 ml decrease or increase for the next patient, respectively.

RESULTS

The mean (sd) MEAV50 for femoral nerve block was 15 (4) ml (95% CI, 7-23 ml) in group US and 26 (4) ml (95% CI, 19-33 ml) in group NS (P = 0.002). The effective dose in 95% of cases (ED95) calculated with probit transformation and logistic regression analysis was 22 ml (95% CI, 13-36 ml) in group US, and 41 ml (95% CI, fs 24-66 ml) in group NS.

CONCLUSIONS

Ultrasound guidance provided a 42% reduction in the MEAV of ropivacaine 0.5% required to block the femoral nerve as compared with the nerve stimulation guidance.

A Prospective, Randomized Comparison between Ultrasound and Nerve Stimulation Guidance for Multiple Injection Axillary Brachial Plexus Block

Background

This prospective, randomized, blinded study tested the hypothesis that ultrasound guidance can shorten the onset time of axillary brachial plexus block as compared with nerve stimulation guidance when using a multiple injection technique.

Methods

Sixty American Society of Anesthesiology physical status I-III patients receiving axillary brachial plexus block with 20 ml ropivacaine, 0.75%, using a multiple injection technique, were randomly allocated to receive either nerve stimulation (group NS, n = 30), or ultrasound guidance (group US, n = 30) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, the need for general anesthesia (failed block) or greater than 100 microg fentanyl (insufficient block) to complete surgery, procedure-related pain, success rate, and patient satisfaction.

Results

The median (range) number of needle passes was 4 (3-8) in group US and 8 (5-13) in group NS (P = 0.002). The onset of sensory block was shorter in group US (14 +/- 6 min) than in group NS (18 +/- 6 min) (P = 0.01), whereas no differences were observed in onset of motor block (24 +/- 8 min in group US and 25 +/- 8 min in group NS; P = 0.33) and readiness to surgery (26 +/- 8 min in group US and 28 +/- 9 min in group NS; P = 0.48). No failed block was reported in either group. Insufficient block was observed in 1 patient (3%) of group US and 2 patients (6%) of group NS (P = 0.61). Procedure-related pain was reported in 6 patients (20%) of group US and 14 patients (48%) of group NS (P = 0.028); patient acceptance was similarly good in the two groups.

Conclusion

Multiple injection axillary block with ultrasound guidance provided similar success rates and comparable incidence of complication as compared with nerve stimulation guidance.

Stimulating or conventional perineural catheters after hallux valgus repair: a double-blind, pharmaco-economic evaluation

BACKGROUND

We prospectively evaluated direct analgesia-related costs of continuous sciatic nerve block using either a stimulating or conventional catheter after hallux valgus repair.

METHODS

The perineural catheter was inserted through a stimulating introducer either blindly (group Conventional, n= 38) or while stimulating via the catheter (group Stimulating, n= 38). Nerve block was induced with 25 ml of mepivacaine 15 mg/ml, and was followed 3 h later by a patient-controlled infusion of ropivacaine 2 mg/ml (basal infusion: 3 ml/h; incremental dose: 5 ml; lock-out time: 30 min). Rescue tramadol [100 mg intravenous (i.v.)] was given if required. Local anesthetic consumption, need for rescue tramadol and post-operative nausea and vomiting (PONV) treatment, and patient's satisfaction were recorded during first 24-h infusion. Cost calculations were based on the acquisition cost of drugs and devices.

RESULTS

Both techniques were similarly effective, but local anesthetic consumption and need for rescue analgesics were lower in the Stimulating group [respectively, 120 vs. 153 ml (P= 0.004) and 21% vs. 60% (P= 0.001)]. The analgesia-related costs for 24 h were similar when 100-ml bags of ropivacaine 2 mg/ml were used (66 euro vs. 67 euro; P= 0.26). When 200-ml bags of ropivacaine were used, the analgesia-related costs were higher in the Stimulating group than the Conventional group (75 euro vs. 55 euro; P= 0.0005).

CONCLUSIONS

Direct costs of continuous sciatic nerve block ranged from 55 to 75 euro. Stimulating catheters reduced local anesthetic consumption and need for rescue analgesics. This was only cost effective when 100-ml bags of 2 mg/ml ropivacaine were used, while the cheapest combination was the use of conventional catheters and 200-ml bags of ropivacaine.

Transcutaneous monitoring of partial pressure of carbon dioxide in the elderly patient: a prospective, clinical comparison with end-tidal monitoring

STUDY OBJECTIVE

To evaluate the accuracy and precision of estimation of partial pressure of carbon dioxide (Pa(CO2)) using end-tidal or transcutaneous CO2 (TcP(CO2)) measurements during mechanical ventilation in the elderly patient.

DESIGN

A prospective, observational study was conducted.

SETTINGS

The study was done in the anesthesia department of a university hospital.

PATIENTS

Seventeen anesthetized, mechanically ventilated patients older than 60 years were studied.

INTERVENTIONS AND MEASUREMENTS

During standard sevoflurane anesthesia, and after proper calibration and an equilibration time of 30 minutes with stable hemodynamic and respiratory variables, arterial (Pa(CO2)), end-tidal (Pet(CO2)), and transcutaneous (TcP(CO2)) CO2 partial pressures were determined. In each patient, 1 to 5 sample sets (Pa(CO2), Pet(CO2), and TcP(CO2)) were obtained.

MAIN RESULTS

A total of 45 sample sets were obtained from the patients studied. The Pa(CO2) values ranged between 21 and 58 mm Hg. The Pa(CO2) - Pet(CO2) tension gradient was 6 +/- 5 mmHg (95% confidence interval, -3 to 16 mmHg), whereas the Pa(CO2) - TcP(CO2) tension gradient was 2 +/- 4 mmHg (95% confidence interval, -6 to 9 mmHg) (P = 0.0005). The absolute value of the difference between Pa(CO2) and Pet(CO2) was 3 mm Hg or less in 7 of 45 sample sets (15%), whereas the absolute value of the difference between Pa(CO2) and TcP(CO2) was 3 mm Hg or less in 21 of 45 sample sets (46%) (P = 0.003). Linear regression analysis for TcP(CO2) versus Pa(CO2) showed a slope of 0.84 (r(2) = 0.73), whereas the linear regression analysis for Pet(CO2) versus Pa(CO2) showed a slope of 0.54 (r(2) = 0.50).

CONCLUSION

Transcutaneous monitoring of CO(2) partial pressure gives a more accurate estimation of arterial CO(2) partial pressure than does Pet(CO2) monitoring.

Anatomy and imaging of lumbar plexus

Sensory and motor innervation of the whole lower limb is due to lumbo-sacral-plexus that arises from the spinal roots L1-S3. The whole lower limb can be blocked from its origin to the foot for surgical procedures or for postoperative analgesia. Single or continuous lumbar plexus blockade can be an alternative to general anesthesia and central block in elective and traumatic hip or femur repair, for knee surgery and for postoperative analgesia. To understand the relative plexus depth and the relationship between the plexus and the closer structure in order to avoid complicance, the aid of imaging technique such as CT-scan, MRI and ultrasounds can be considered.