Neuraxial pathology and regional anesthesia: an education guide to decision-making

In current clinical practice, spinal anesthesia and analgesia techniques-including epidural and subarachnoid procedures-are frequently executed without imaging like X-ray or epidurography. Unrecognized spinal pathology has resulted in serious morbidity in the context of performing neuraxial anesthesia. Typically, preoperative consultations incorporate a patient's medical history but lack a detailed spinal examination or consideration of recent MRI or CT scans. In contrast, within the domain of pain clinics, a multidisciplinary approach involving anesthesiologists and neuroradiologists is common. Such collaborative settings rely on exhaustive clinical history and scrutinization of recent imaging studies, which may influence the decision to proceed with invasive spinal interventions. There are no epidemiological data concerning rates of the different baseline pathologies that would potentially pose morbidity risks from neuraxial procedures, but the most common among these is canal stenosis, which significantly affects almost 20% of people over 60 years of age. This paper aims to elucidate these critical findings and advocate for incorporating meticulous preoperative assessments for individuals slated for spinal anesthesia or analgesia procedures, thereby attempting to mitigate potential risks.

Prone Position MRI of the Lumbar Spine in Patients With Low Back Pain and/or Radiculopathy Refractory to Treatment

BACKGROUND

There are patients with limiting low back pain (LBP) with or without radicular pain in whom conventional supine magnetic resonance imaging (MRI) show no causative pathology. Despite the limitations of dynamic axially loaded MRI examinations, these imaging studies have shown a striking ability to diagnose pathology unrecognized by conventional MRI. The difference in findings between supine and prone MRI with patient symptom correlation has not been studied.

METHODS

Nineteen patients suffering from chronic moderate-to-severe LBP and/or radicular pain nonresponsive to conventional therapy or interventional treatment, were included in this study. Both supine and prone MRIs were performed and analyzed by a neuroradiologist. Specific supine and prone measurements were registered, including spinal canal area, lateral recess diameter, foraminal area, and ligamentum flavum thickness. Three-dimensional  MRI reconstructions of varying pathology patterns were created.

RESULTS

The mean patient age was 48.7 years (range [R]: 30-69), 63% of patients were women. The mean numeric pain score  was 6.5 (R: 4-8). In 52.6% of cases, disc pathology/increased disc pathology was seen only on prone imaging. We observed significant buckling and increased thickness of the ligamentum flavum in 52.6 % of cases in the prone position that was absent from the supine MRIs. We also documented varying grades of spondylolisthesis and facet joint subluxation resulting in significant foraminal stenosis in 26.3% of prone cases not seen from supine MRIs.

CONCLUSIONS

Four patterns of pathological findings have been identified by MRI performed in the prone position. These findings were not observed in the supine position. Prone MRI can be a significant and useful tool in the diagnosis and treatment of patients with back pain refractory to treatment whose conventional supine MRIs appeared unremarkable.

Painful Total Hip Arthroplasty: A Systematic Review and Proposal for an Algorithmic Management Approach

BACKGROUND

The etiological diagnosis of painful primary total hip arthroplasty and its management is a complex clinical challenge for pain physicians. Extrinsic sources of pain in the hip joint might be efficiently treated by clinical pain units, although the topic remains controversial.

OBJECTIVES

To conduct a literature review and suggest an evidence-based algorithmic approach to managing painful hip arthroplasty.

STUDY DESIGN

Systematic literature review with qualitative data synthesis.

METHODS

We conducted an online search of Medline/Pubmed, Embase, Clinical Trials, and Cochrane database using the Medical Subject Heading (MeSH) and free terms on all biomedical literature published up to August 2019. Articles that described either the etiologies and management of painful primary total hip arthroplasty or the imaging techniques to specifically assess any of its causes were included. We collected the demographic data (gender, age, body mass index), main etiologies, diagnostic tests, and specific treatments applied in each study. Based on the reviewed evidence, we propose an algorithmic approach, with a special emphasis on etiologies that should be referred to pain clinics.

RESULTS

Twenty-four studies were included for the synthesis, 16 of which were observational studies and 8 of which were non-systematic literature reviews that described a wide range of etiologies of painful primary total hip arthroplasty. The results showed that 2/3 of the causes of pain were intrinsic and need to be managed by orthopedic surgeons. One third of the etiologies were extrinsic and should be referred to pain clinics once intrinsic causes have been ruled out. Among extrinsic sources of pain, the most frequent was myofascial etiology.

LIMITATIONS

A publication bias might have been present due to the inclusion of studies published only in English, Spanish, and German. The included studies also had heterogeneous methodologies.

CONCLUSIONS

The current review suggests that painful hip arthroplasty is not a rare condition in clinical practice. We systematically reviewed etiologies and various treatments published in the literature and we suggest an algorithmic approach to management based on the available evidence. This approach incorporates the evidence regarding our knowledge of the etiologies, diagnosis, and management of chronic pain after total hip arthroplasty. Systematic review registration: The protocol was registered in PROSPERO the international prospective register of systematic reviews, ID CRD42020185663.

Painful Total Hip Arthroplasty: A Systematic Review and Proposal for an Algorithmic Management Approach

Background: The etiological diagnosis of painful primary total hip arthroplasty and its management is a complex clinical challenge for pain physicians. Extrinsic sources of pain in the hip joint might be efficiently treated by clinical pain units, although the topic remains controversial. Objectives: To conduct a literature review and suggest an evidence-based algorithmic approach to managing painful hip arthroplasty. Study Design: Systematic literature review with qualitative data synthesis. Methods: We conducted an online search of Medline/Pubmed, Embase, Clinical Trials, and Cochrane database using the Medical Subject Heading (MeSH) and free terms on all biomedical literature published up to August 2019. Articles that described either the etiologies and management of painful primary total hip arthroplasty or the imaging techniques to specifically assess any of its causes were included. We collected the demographic data (gender, age, body mass index), main etiologies, diagnostic tests, and specific treatments applied in each study. Based on the reviewed evidence, we propose an algorithmic approach, with a special emphasis on etiologies that should be referred to pain clinics. Results: Twenty-four studies were included for the synthesis, 16 of which were observational studies and 8 of which were non-systematic literature reviews that described a wide range of etiologies of painful primary total hip arthroplasty. The results showed that 2/3 of the causes of pain were intrinsic and need to be managed by orthopedic surgeons. One third of the etiologies were extrinsic and should be referred to pain clinics once intrinsic causes have been ruled out. Among extrinsic sources of pain, the most frequent was myofascial etiology. Limitations: A publication bias might have been present due to the inclusion of studies published only in English, Spanish, and German. The included studies also had heterogeneous methodologies. Conclusions: The current review suggests that painful hip arthroplasty is not a rare condition in clinical practice. We systematically reviewed etiologies and various treatments published in the literature and we suggest an algorithmic approach to management based on the available evidence. This approach incorporates the evidence regarding our knowledge of the etiologies, diagnosis, and management of chronic pain after total hip arthroplasty. Systematic review registration: The protocol was registered in PROSPERO the international prospective register of systematic reviews, ID CRD42020185663. Key words: Chronic pain, review, pain management, arthroplasty, hip replacement

Quantitative Sensory Testing in pain assesment and treatment. Brief review and algorithmic management proposal

Quantitative Sensory Testing (QST) is used to globally analyze the nociceptive system in order to obtain a more objective understanding of pain perception. In recent years, QST has become a common tool in many pain clinics and anesthesiology departments worldwide. In 2013, the Neuropathic Pain Special Interest Group of the IASP put forward the first recommendations for conducting QST in clinical practice and research. However, the wide variety of QST methodologies and standards in the literature make it difficult to generalize the used of this tool in clinical practice. In this study, we present the basic concepts of QST, the type of tests and devices used, how they are applied, and the role of QST in anesthesiology and pain management.

Transforaminal Epiduroscopy in Patients with Failed Back Surgery Syndrome

BACKGROUND

Epiduroscopy is a useful diagnostic and therapeutic tool for managing failed back surgery syndrome (FBSS). The conventional approach is via either the sacral hiatus or the interlaminar. Major causes of FBSS include epidural fibrosis, disc herniation, and stenosis. When these problems are located at the intervertebral foramen level, it can be difficult to reach the lateral recess and the foramen with the epiduroscope. Transforaminal epiduroscopy could be a useful alternative approach in patients with FBSS located at the foraminal level.

OBJECTIVE

We present a new procedure for lumbar epiduroscopy via a transforaminal approach and its application in patients with FBSS. The technique is described and long-term results are reported.

STUDY DESIGN

This study used a single-arm prospective observational design.

SETTING

The research took place at the University Hospital in Spain.

METHODS

Patients with FBSS suffering severe chronic radicular pain (Numeric Rating Scale [NRS-11] > 7) who had not responded to other treatments were included. Selective root stimulation during a pulsed radiofrequency procedure confirmed the origin of pain by means of an exact reproduction of typical pain. Transforaminal epiduroscopy was performed at the affected level. The severity of fibrosis observed was recorded. The NRS-11 score was reevaluated at 1, 6, and 12 months after the procedure. Any complications related to the treatment were recorded.

RESULTS

Twenty-four patients were included. The mean number of back surgeries was 1.66 (range, 1-5). The basal NRS-11 score was 7.83 (0.14); at 1 month, 3.66 (0.38) (P < 0.001); at 6 months, 4.46 (0.48) (P < 0.01); and at 1 year after treatment, 4.17 (0.51) (P < 0.01). Most patients (54%; 95% CI, 34%-74%) obtained > 50% pain reduction on the NRS-11, maintained during a 1-year follow-up period. No major complications were registered.

LIMITATIONS

The research was limited by the lack of a control group.

CONCLUSIONS

We have described a new procedure for epiduroscopy via the transforaminal approach. It is a useful and safe approach to managing FBSS at the foraminal level and shows better long-term results than other endoscopic procedures.

KEY WORDS

Epidural, epiduroscopy, chronic pain, spinal cord, back surgery.

[Epiduroscopy]

Epiduroscopy is a minimally invasive diagnostic and therapeutic technique used in patients with chronic low back pain with or without radiculopathy. Epiduroscopic procedures are particularly indicated in cases of failed spinal surgery. This review discusses the indications, contraindications, and complications of the technique, describing in detail the sacral (caudal) and interlaminar approaches and noting their advantages and disadvantages. Practical recommendations are made, along with an attempt to assess future prospects for epiduroscopy.

Interlaminar approach for epiduroscopy in patients with failed back surgery syndrome

BACKGROUND

Epiduroscopy is a relatively new diagnostic and therapeutic technique used in patients with chronic low back pain with or without radiculopathy. We present our experience with a new interlaminar approach in patients with failed back surgery syndrome (FBSS).

METHODS

Patients with severe symptoms of FBSS who did not respond to other treatments were included. Lumbar epiduroscopy was performed via interlaminar approach through a 14 G epidural needle under fluoroscopy. A flexible, 0.77 mm, endoscope was introduced through a 4F catheter into the epidural space and advanced in a cephalad direction. Flushes of normal saline through the catheter (via a Y-adapter/haemostasis valve) enabled distension of the space. Adhesions were mechanically mobilized under direct vision. A mixture of triamcinolone 60 mg, hyaluronidase 600 IU, and bupivacaine 0.0625% was instilled.

RESULTS

Nineteen patients were included. The mean number of operations at lumbar level was 2.26. Major findings included adhesions, inflammation, stenosis, and nerve root hypotrophia. The visual analogue scale (VAS) score was 7.89 at baseline, 5.95 (P<0.001) 3 months later, and 6.05 (P<0.001) 6 months later. Six patients (31.6%) did not show any improvement, and six other patients showed a very significant improvement (at least three points reduction in the VAS) 3 months later. We had four cases of dural puncture, but only one patient required hospital admission.

CONCLUSIONS

We have described a new procedure for epiduroscopy with approximately 50% reduced outer diameter of the catheter, which allows interlaminar approach. Its diagnostic efficacy is clear and there were a significant number of patients who had improved outcome.

Trigeminal nerve palsy and Horner’s syndrome following epidural analgesia for labor: a subdural block?

Horner's syndrome is a rare complication of epidural analgesia for labor. Much more uncommon is trigeminal nerve palsy. Both complications may be attributed to a subdural localization of the catheter, as we demonstrated clinically by a repeat injection and patchy sympathetic block and with the typical image on epidurography.

Bolus application of remifentanil with propofol for dilatation and curettage

BACKGROUND AND OBJECTIVE

This study was designed to determine which single bolus dose of remifentanil in combination with propofol and nitrous oxide is best to control the haemodynamic, autonomous and somatic responses in patients scheduled for dilatation and curettage of the uterine cervix. We evaluated the adequacy of different bolus doses of remifentanil, associated with propofol and nitrous oxide, for dilatation and curettage in a prospective double-blind study.

METHODS

After institutional approval and informed consent, 34 healthy females undergoing curettage to remove material from the uterus after spontaneous abortion were randomized to receive remifentanil 0.5 microg kg(-1) intravenously (i.v.) (Group A; n = 4), 1 microg kg(-1) i.v. (Group B; n = 15) or 1.5 microg kg(-1) i.v. (Group C; n = 15), with propofol 2 mg kg (-1) i.v. in all groups. Anaesthesia was maintained with 60% nitrous oxide in oxygen. Haemodynamic, somatic and autonomic signs of light anaesthesia were registered to assess the response to surgical stress. Recovery times and Aldrete score were recorded at the end of the procedure.

RESULTS

The groups were similar with regard to biometric data and duration of surgery. The poor results using the lowest dose of remifentanil obliged us to abandon this dose. The total dose of remifentanil was larger in Group C (100 +/- 5.7 microg vs. 65 +/- 4.1 microg in Group B; P < 0.05), but more patients required extra bolus injections in Group B (69% vs. 38% in Group C; P < 0.01). Recovery times were significantly shorter in Group C. Aldrete scores when leaving the operation room was similar.

CONCLUSIONS

Remifentanil 1.5 microg kg(-1) i.v. with propofol 2 mg kg(-1) i.v. and 60% nitrous oxide in oxygen provided the best anaesthetic control with the fastest recovery times.

Effect of nitroglycerine in popliteal preparations from patients with peripheral occlusive arteriopathy precontracted with KCl or 5-hydroxytryptamine

1. At the present time, there are no studies in isolated arteries from patients suffering from peripheral occlusive arteriopathy (POA). In the present study, we attempt to characterize the effect of nitroglycerine (GTN) in isolated popliteal preparations obtained after leg amputation in 60-90-year-old men and women suffering from POA. 2. After surgical operation, arterial samples were stored in a refrigerator at 4 degrees C and, after 12-36 h, they were cut into rings and mounted in organ baths containing Krebs'-Henseleit solution at 37 degrees C and gassed constantly with 95% CO2 and 5% O2. Because noradrenaline elicited very poor contractile responses in these preparations, in the present study we evaluated the concentration-dependent contractions induced by KCl (15-90 mmol/L) and 5-hydroxytryptamine (5-HT; 10-7 to 10-4 mol/L) in arteriopathic popliteal rings and, when the corresponding maximum contractile effect had been obtained, we also evaluated the concentration-dependent relaxing effect produced by GTN (10-10 to 10-5 mol/L) in all precontracted preparations. As a reference, similar experiments were performed in popliteal preparations obtained following surgery on non-arteriopathic vascular tissue where it was necessary to resect a certain percentage of healthy vessel. 3. The responses to KCl and 5-HT were greater in healthy vessel than in arteriopathic rings. The relaxing effect of GTN was greater in preparations precontracted with 5-HT than in those preparations precontracted with KCl. In addition, preparations precontracted with KCl relaxed even less when they were obtained from patients with POA. 4. The present data indicate that GTN is a vasodilator with little effect on depolarized arteries. The results also indicate that the effect of this drug is even less in depolarized arteries from patients with POA.

Importance of creatine kinase activity for functional recovery of myocardium after ischemia-reperfusion challenge

To define the relation between the phosphoryl transfer via creatine kinase and the ability to recover from an ischemia-reperfusion challenge, the authors chemically inhibited creatine kinase activity with iodoacetamide (IAm) and then measured myocardial recovery after 2, 10, or 30 min of global ischemia followed by 30 min of reperfusion in the isolated, arterially perfused interventricular septa of the rabbit heart. During normoxia, IAm (0.5 M perfused for 15 min) did not by itself modify developed tension, maximal rate of tension development, or resting tension. In ischemia, IAm pretreatment increased the rate of developed tension loss and highly diminished developed tension recovery after reperfusion for all the ischemia periods tested. Moreover, IAm significantly enhanced the maximal increase in the resting tension induced by 10 or 30 min of ischemia plus reperfusion. Lactate dehydrogenase activity in reperfusion was also significantly increased over untreated septa. On the basis of the present results, the authors suggest that the aggravating effects exhibited by IAm on the ischemic myocardium are compatible with its creatine kinase inhibition properties and that creatine kinase activity is essential for full recovery from an ischemia-reperfusion challenge.

Cardiopulmonary resuscitation training for students of odontology: skills acquisition after two periods of learning

INTRODUCTION

Although life threatening emergencies in dental practice are not frequent, dentists have to be competent in providing basic life support (BLS).

OBJECTIVES

The aim of this work was to study the level of skills acquisition among dentistry students in two different periods of one rescuer-BLS training, a first short practice training of 2 h followed by 8 h of practice over a period of 2 months.

METHODS

One hundred and sixteen second-year undergraduate students of Anesthesiology at the Dental School of the Complutense University in Madrid were tested at the end of the two periods of learning using a recording manikin with a validated scoring system (Laerdal Resusci-Anne). This manikin recorded the percentage of adequate chest compressions and insuflations, rate of chest compressions and the causes of error in each case.

RESULTS

Final global results were, 51.66+/-3.0% adequate chest compressions; and 54.44+/-3.61% adequate insuflations. The kinds of errors where different in both tests were, wrong hand position (26.92+/-2.96 vs. 12.29+/-2.40%, P<0.001); excessive compressions (27.71+/-2.90 vs. 16.02+/-2.33%, P<0.05); and weak compressions (23.28+/-3.24 vs. 16.77+/-2.57%, P<0.05). Regression analysis found a positive correlation among excessive compression, height and weight (P<0.001) and a negative correlation between weak compression, height and weight (P<0.001).

CONCLUSIONS

The poor overall results, although similar to those shown in the literature, have made us question the validity of our methods of teaching BLS. We were able to establish a correlation between demographic and sociocultural variables with the typical errors, and to begin the process of improving our teaching methods.

Continuous monitoring of oesophageal pH during general anaesthesia with laryngeal mask airway in children

We studied the incidence of gastro-oesophageal reflux (GOR) during general anaesthesia with the laryngeal mask airway (LMA) in a paediatric population with two ventilatory regimes: spontaneous breathing and controlled mechanical ventilation (CMV). Thirty children between 6 months and 15 years, ASA I-II, for routine surgery, were randomly assigned in two groups: spontaneous ventilation (n=14), and CMV (n=16). A pH probe was situated in the central third of the oesophagus. Some 66% of the patients breathing spontaneously had GOR episodes vs. 92% of the patients with CMV (P < 0,01). Reflux took place mainly after LMA removal (21% vs. 68%; P < 0,01) and in the Postanaesthetic Care Unit (PACU) (29% vs. 43%; P < 0,05). There was a high incidence of GOR during general anaesthesia and in the PACU in paediatric patients anaesthetized with the LMA. GOR episodes were significantly more evident in the CMV group, mainly after LMA removal, but without clinical significance.

Fatal paradoxical air embolism during liver transplantation

We describe a case of fatal paradoxical coronary air embolism during liver transplantation. The literature on the diagnosis and prophylaxis of paradoxical air embolism during liver transplantation is reviewed and discussed.

Presence of a nitric oxide synthase inhibitor in the graft efflux during reperfusion in human liver transplantation

Involvement of the nitric oxide (NO) system in complications following human orthotopic liver transplants (OLT) has been reported, but the contribution of the graft to the modulation of the NO system during reperfusion in normal OLT has not been characterized. We have studied the contribution of the graft efflux to the modulation of the NO system in 20 consecutive OLT. We evaluated its effects on isolated vascular reactivity of the rabbit and on rat cultured macrophages stimulated with lipopolysaccharide (LPS). In none of the donor liver biopsies was expression of inducible NO synthase (iNOS) activity by Northern or Western blot analysis found. Graft efflux after the onset of liver reperfusion, but not pre-transplant patient plasma, reversibly inhibited the acetylcholine-induced relaxation of norepinephrine-contracted rabbit aortic rings. Moreover, graft efflux reversibly inhibited NO production in rat macrophages treated with LPS, as evidenced by both a decrease in nitrite plus nitrate formation and a decrease in the production of [14C]citrulline from [14C]arginine. Addition of a 10% dilution of graft efflux to cultured rat macrophages incubated with LPS increased iNOS mRNA levels, suggesting direct inhibition of the enzyme but not of its expression. These results cannot be ascribed to the depletion of arginine the iNOS substrate since they can be reproduced even in the presence of an excess (10 mM) of exogenously added arginine. No correlation was found between the iNOS inhibitory activity in each sample and the corresponding clinical parameters related to either the graft function after the OLT or the existence of post-reperfusion syndrome. Our results indicate the existence of a soluble factor in the graft efflux from human OLT that reversibly and unspecifically inhibits NOS activity. Its involvement in the physiology and/or pathology of human liver diseases deserves further study.

Protective effects of cyclopiazonic acid on ischemia-reperfusion injury in rabbit hearts

The cardioprotective effects on myocardial ischemia of the sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) inhibitor, cyclopiazonic acid (CPA), were studied. We used the isolated arterially perfused interventricular septum of the rabbit heart submitted to 30-min global ischemia/30-min reperfusion. Mechanical [maximal increase in resting tension (MIRT), and the recovery of developed tension (RDT)], and biochemical parameters [creatine phosphokinase activity (CPK) in the effluent] were analyzed. CPA, 1 microM, perfused 30 min before the ischemia intervention significantly increased RDT by 54% and lessened MIRT by 66%. CPA also decreased CPK in the perfusate by 67.7 and 71.4% at 0-2 and 5-7 min of reperfusion, respectively. No additional benefits were shown either when the drug was perfused, both during ischemia and reperfusion, or with higher CPA concentrations (10-30 microM). The CPA cardioprotection was lost when the drug was present only during the reperfusion period. CPA exhibits functional and biochemical cardioprotective effects on myocardial ischemia. We postulated a decreased SR calcium contribution to the initial cytoplasmic calcium overload as the most probable mechanism involved.

Pourfour du Petit syndrome: a case following a traffic accident with severe cranioencephalic trauma

Poufour du Petit syndrome is an extraordinarily unusual clinical condition produced by hyperactivity of the sympathetic cervical chain as a consequence of irritation of these nerves. It causes an ipsilateral mydriasis, which, in patients suffering a head injury as in the case reported here, can confuse the diagnosis and disconcert physicians.