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Regional anaesthesia is the use of local anaesthetic drugs to block sensations of pain from a large area of the body. It is used to allow surgery to proceed either without general anaesthesia or combined with general anaesthesia to provide superior pain relief than can be achieved with analgesic drugs alone. It is broadly divided into two categories. Neuraxial blocks involve injection of local anaesthetic close to the spinal cord, such as in the subarachnoid (intrathecal) space (known as a spinal) or in the epidural space (known as an epidural). Peripheral nerve blocks involve injection of local anaesthetic near peripheral nerves or plexuses. This can be performed either using landmark technique, a nerve stimulator, or with ultrasound guidance depending on the chosen block. Common equipment and techniques used to perform regional anaesthesia are discussed in this chapter, as well as advantages, potential risks, and the patient preparation and monitoring that is required.
The definition and classification of polycystic ovary syndrome (PCOS) have been an important but controversial topic for many decades with significant implications for treatment and prognosis. The 2018 international guideline incorporates evidence-based evaluation of the condition together with clinical, consumer, academic and industry contributions to set up the most accepted approach to diagnosis, evaluation and treatment available internationally.
Non-physician performed point-of-care ultrasound (POCUS) is emerging as a diagnostic adjunct with the potential to enhance current practice. The scope of POCUS utility is broad and well-established in-hospital, yet limited research has occurred in the out-of-hospital environment. Many physician-based studies expound the value of POCUS in the acute setting as a therapeutic and diagnostic tool. This study utilized a scoping review methodology to map the literature pertaining to non-physician use of POCUS to improve success of peripheral intravenous access (PIVA), especially in patients predicted to be difficult to cannulate.
Ovid MEDLINE, CINAHL Plus, EMBASE, and PubMed were searched from January 1, 1990 through April 15, 2021. A thorough search of the grey literature and reference lists of relevant articles was also performed to identify additional studies. Articles were included if they examined non-physician utilization of ultrasound-guided PIVA (USGPIVA) for patients anticipated to be difficult to cannulate.
A total of 158 articles were identified. A total of 16 articles met the inclusion criteria. The majority of participants had varied experience with ultrasound, making accurate comparison difficult. Training and education were non-standardized, as was the approach to determining difficult intravenous access (DIVA). Despite this, the majority of the studies demonstrated high first attempt and overall success rates for PIVA performed by non-physicians.
Non-physician USGPIVA appears to be a superior method for PIVA when difficulty is anticipated. Additional benefits include reduced requirement for central venous catheter (CVC) or intraosseous (IO) needle placement. Paramedics, nurses, and emergency department (ED) technicians are able to achieve competence in this skill with relatively little training. Further research is required to explore the utility of this practice in the out-of-hospital environment.
Considering the influence of body’s growth and development on thyroid volume (TVOL), whether five existed corrected methods could be applied to correct TVOL remains unclear, in terms of Chinese children’s increased growth and development trends. This study aimed to compare the applicability of five correction methods: Body Surface Area corrected Volume (BSAV), Body Mass Indicator corrected Volume (BMIV), Weight and Height corrected Volume Indicator (WHVI), Height corrected Volume Indicator 1 (HVI1) and Height corrected Volume Indicator 2 (HVI2) and to establish the reference values for correction methods. The data of Iodine Nutrition and Thyroid Function Survey were used to analyse the differences in TVOL between normal and abnormal thyroid function children. Data of National Iodine Deficiency Disorders Survey were used to compare five correction methods and to establish their reference values. The median urinary iodine concentrations of children surveyed were 256·1 μg/l in 2009 and 192·6 μg/l in 2019. No significant difference was found in TVOL and thyroid goitre rate between children with normal and abnormal thyroid function. In the determination of goitre, HVI1, HVI2, BSAV and BMIV all showed high agreement with TVOL, while the area under the receiver operating characteristic curve (AUC) of WHVI was relatively low for children aged 8 (AUC = 0·8993) and 9 (AUC = 0·8866) years. Most differences of TVOL between light and heavy weight, short and tall height children can be eliminated by BSAV. BSAV was the best corrected method in this research. Reference values were established for corrected TVOL in Chinese children aged 8–10 years by sex.
Paramedics received training in point-of-care ultrasound (POCUS) to assess for cardiac contractility during management of medical out-of-hospital cardiac arrest (OHCA). The primary outcome was the percentage of adequate POCUS video acquisition and accurate video interpretation during OHCA resuscitations. Secondary outcomes included POCUS impact on patient management and resuscitation protocol adherence.
A prospective, observational cohort study of paramedics was performed following a four-hour training session, which included a didactic lecture and hands-on POCUS instruction. The Prehospital Echocardiogram in Cardiac Arrest (PECA) protocol was developed and integrated into the resuscitation algorithm for medical non-shockable OHCA. The ultrasound (US) images were reviewed by a single POCUS expert investigator to determine the adequacy of the POCUS video acquisition and accuracy of the video interpretation. Change in patient management and resuscitation protocol adherence data, including end-tidal carbon dioxide (EtCO2) monitoring following advanced airway placement, adrenaline administration, and compression pauses under ten seconds, were queried from the prehospital electronic health record (EHR).
Captured images were deemed adequate in 42/49 (85.7%) scans and paramedic interpretation of sonography was accurate in 43/49 (87.7%) scans. The POCUS results altered patient management in 14/49 (28.6%) cases. Paramedics adhered to EtCO2 monitoring in 36/36 (100.0%) patients with an advanced airway, adrenaline administration for 38/38 (100.0%) patients, and compression pauses under ten seconds for 36/38 (94.7%) patients.
Paramedics were able to accurately obtain and interpret cardiac POCUS videos during medical OHCA while adhering to a resuscitation protocol. These findings suggest that POCUS can be effectively integrated into paramedic protocols for medical OHCA.
The significant advances in ultrasound technology have resulted in an increase in the prevalence of PCO morphological ultrasonographic criteria diagnosis. These patients have a live birth rate after undergoing up to three cycles of IVF treatment that is 82% higher than women with normal ovaries, requiring fewer ampules of gonadotrophins, producing more follicles and viable oocytes with similar fertilisation and miscarriage rates. Since these women exhibit an exaggerated response to gonadotrophin therapy regardless of COH protocol, the risk remains the increased prevalence of OHSS. Since no COH protocol is superior to manage these patients, protocols that trigger oocyte maturation with a GnRH agonist, with or without a ‘freeze-all’ approach, should be encouraged. Therefore, it is important that every patient undergoing IVF has a baseline ultrasound scan, antral follicle count and AMH levels as well as an assessment of ovarian morphology prior to ART treatments in order to assess risk and reduce complications.
Prenatal fetal monitoring allows for the detection of abnormal physiologic conditions in the fetus. The different available methods can detect abnormalities in utero-placental perfusion, as well as physiologic changes during and after in-utero fetal surgery. Basic antepartum fetal monitoring in viable fetuses has advanced over the years and now involves not only the nonstress test but more advanced methods which also take into account the ultrasound findings. Comprehension of the different fetal heart rate tracings allow for rapid intervention where necessary. Unfortunately, while many modes of surveillance exist, no single method can accurately identify a fetus that will progress to being stillbirth.
Delivery of enteral nutrition in critical infants post-paediatric cardiac surgery is sometimes hampered, necessitating direct feeding into the small intestine. This study is highlighting the role of ultrasound-guided post-pyloric feeding tube insertion performed by the paediatric cardiac ICU intensivist in critically ill infants.
We carried out a prospective pilot observational experimental study in peri-operative cardiac infants with feeding intolerance between 2019 and 2021. Feeding tube insertion depends on a combination of ultrasound and gastric insufflation with air-saline mixture. Insertion was confirmed by bedside abdominal X-ray.
Out of 500 peri-operative cardiac infants, 15 needed post-pyloric feeding tube insertion in median 15 postoperative day. All were under 6 months of age with average weight of 3 ± 0.2 kg. Median Risk Adjustment for Congenital Heart Surgery Categories was 4. Median insertion time was 15 minutes. No complications have been reported. First pass success rate was 87%, while a second successful insertion attempt was needed in 2 cases (13%). Target daily calorie intake was achieved within average of 3.5 ± 0.4 days. Mean post-pyloric feeding tube stay was 20 ± 3 days. Out of 15 infants, 3 patients died, 1 patient needed gastrostomy tube, and 11 patients were discharged home on oral feeds.
Ultrasound-guided post-pyloric feeding tube insertion using gastric insufflation with air-saline mixture in peri-operative cardiac infants with feeding intolerance is a useful and practical bedside tool, and it can be performed by a trained paediatric cardiac ICU intensivist. It may have potential positive effects on morbidity and outcome.
Abortion training is a required component of US ob-gyn graduate medical education training and recommended in family medicine training. While individual residents may choose to opt out of training in certain conditions – namely personal or religious conflicts- this chapter describes the importance of facilitating participation of residents up to their comfort level in order to learn the essential and transferable skills in the provision of women’s health care. This chapter describes the history of partial participation and provides evidence from multiple studies which have found that learners who object to abortion but partially participate in training in family planning and abortion gain important clinical and professional skills and appreciate the training. It describes various protocols and guidance for teaching leadership to support partial participation, specifics on setting clear expectations, and suggestions for when to facilitate discussions for residents who aren’t certain about the participation level, or plan to opt out.
Abortion is common medical procedure and the shortage of providers has been widely reported. This chapter describes the history of abortion training in the United States, including the establishment of the Ryan Residency Training Program, and reiterates that to meet patients’ needs, all clinicians who care for women’s reproductive health must be trained in abortion skills – including counseling, preoperative assessment, ultrasound, medication abortion management, uterine evacuation techniques, pain management, and postoperative care. This chapter describes the impacts of abortion training on learners’ clinical skills, attitudes toward patients and abortion provision, and on their professional practice. We describe the challenges in integrating abortion into resident curriculum, and how to find support and resources. We provide evidence of the many benefits of integrated training – including improving resident education and more comprehensive patient care, and argue that training in uterine evacuation skills is critical for all obstetrician-gynecologists.
British Thyroid Association 2014 guidelines emphasised ultrasound assessment of nodules. One ultrasonographic differentiator of debatable relevance is intra-nodular vascularity. This is the first UK study conducted to address this question.
Ultrasound reports for thyroid surgery patients over 10 years were retrospectively reviewed. Reports documenting ‘intra-nodular vascularity or flow’ were analysed. Reports identifying peripheral vascularity only or no intra-nodular flow formed the control group. Concordance with final histology was used to determine the odds ratio for malignancy.
A total of 306 patients were included, and 119 (38.9 per cent) nodules demonstrated intra-nodular vascularity. Of these, 60 (50.4 per cent) were malignant compared with 42 per cent in the control group. Intra-nodular vascularity was not a statistically significant predictor of malignancy with an odds ratio of 1.39 (p = 0.18, 95 per cent confidence interval, 0.86–2.23).
Intra-nodular vascularity in isolation was not a reliable predictor of malignancy. This supports other world literature studies. Although intra-nodular flow should not be relied upon in isolation, interpretation in conjunction with other suspicious findings enhances the predictive value.
Central venous catheter (CVC) placement is an important procedure which is frequently performed in the emergency department (ED) and can cause serious complications. The aim of this study is to introduce a simulation-based tissue model for ultrasound (US)-guided central venous access practices and to compare the effectiveness of static and dynamic US techniques through this model.
This was a prospective study on US-guided CVC placement techniques simulated with a chicken tissue model. This model is based on the principle of placing two cylindrical balloons filled with colored water (red for arterial and blue for venous) between a raw chicken breast and wrapping the formed structure with plastic wrap. The study was conducted in an academic tertiary care hospital with Emergency Medicine (EM) residents who have received basic US training, including vascular access procedures. All participants performed simulated CVC placement procedures with both static and dynamic US techniques. At the end of the study, the practitioners were asked to rate usefulness of these techniques between one and ten (one was the lowest and ten was the highest score).
A total of 32 EM residents were included in the study. Their median age was 29 (IQR = 27 - 31) years and 72% of them were male. Their median duration in ED was 19 (IQR = 12 - 34) months. According to the results of simulated CVC placement procedures, there was no significant difference between the static and dynamic US techniques in terms of puncture numbers, procedure durations, and success rates. However, according to the usefulness scores given by the practitioners, the dynamic US technique was found to be more useful (P < .001).
The chicken tissue model is a convenient tool for simulating US-guided CVC placement procedures. The dynamic US technique is considered to be more useful in this field than the static technique, but the results of practitioner-dependent practices may not always support this generalization.
Ultrasound determination of chorionicity in the first trimester has a high accuracy, but it is associated with some pitfalls. This report presents changes in ultrasound findings during a monochorionic pregnancy with chorionic membrane folding (CMF). The patient was a 32-year-old woman, gravida 2 para 0. Her transvaginal ultrasonography identified two gestational sacs (GSs) and two embryos at 7 weeks of gestation. At 9 weeks’ gestation, an ultrasound image showed a lambda sign at both sides and the interruption of chorionic membranes, resulting in the diagnosis of a monochorionic diamniotic (MCDA) twin pregnancy with CMF. At 11 weeks’ gestation, an ultrasound image showed a lambda sign at one portion of the septum and a T sign at another portion. This change suggested that the folded chorionic membrane had partially flattened. At 35 weeks’ gestation, an emergency cesarean section was performed. Two healthy male neonates were delivered. Histological placental examination confirmed that the intertwin membrane was composed of two amniotic membranes without a folded chorionic membrane, confirming the diagnosis of a MCDA twin pregnancy. This case presents two important ultrasound chorionicity findings: a monochorionic pregnancy with CMF can show two GSs and a lambda sign and the CMF can flatten or change during the pregnancy.
Lisa M. v. Henry Mayo Newhall Memorial Hospital exemplifies the reluctance of many courts to impose vicarious liability in cases of employee sexual abuse, treating cases of sexual abuse differently from other cases. The California Supreme Court in Lisa M. ruled against a pregnant patient who had been sexually molested by a hospital technician under the guise of performing an ultrasound examination. The court determined that the assault was “outside the scope of employment,” not fairly attributable to the employer, and the result only of “propinquity and lust.” The rewritten feminist opinion recharacterizes the assault as an outgrowth of employment, emphasizing that the employee exercised job-created control and power over plaintiff’s body. Because sexual assaults are not uncommon in the healthcare setting, the feminist opinion regards the assault as foreseeable and would allow a jury to determine whether vicarious liability is warranted because the assault was committed within the scope of employment. The accompanying commentary situates the case at the intersection of sexual violence and women’s health and examines how job-created power can make a patient vulnerable to harm by medical professionals.
Ultrasonography is an established modality in medical imaging and is evermore entering clinical practice. This chapter provides an introduction to the principles of clinical ultrasonography. It describes the use of airway ultrasonography for identification of the cricothyroid membrane, the trachea and for confirming correct tracheal intubation. Bedside ultrasonography by the anaesthetist has a much higher success rate than palpation for identifying the cricothyroid membrane, especially in patients with neck pathology. It should be applied before initiation of airway management and not be delayed until airway problems are apparent. The role of lung ultrasonography for identification of normal ventilation and pathology is described. Gastric ultrasonography for assessing the starvation status of a patient is described.
The primary goal of this study was to determine if ultrasound (US) use after brief point-of-care ultrasound (POCUS) training on cardiac and lung exams would result in more paramedics correctly identifying a tension pneumothorax (TPTX) during a simulation scenario.
A randomized controlled, simulation-based trial of POCUS lung exam education investigating the ability of paramedics to correctly diagnose TPTX was performed. The US intervention group received a 30-minute cardiac and lung POCUS lecture followed by hands-on US training. The control group did not receive any POCUS training. Both groups participated in two scenarios: right unilateral TPTX and undifferentiated shock (no TPTX). In both scenarios, the patient continued to be hypoxemic after verified intubation with pulse oximetry of 86%-88% and hypotensive with a blood pressure of 70/50. Sirens were played at 65 decibels to mimic prehospital transport conditions. A simulation educator stated aloud the time diagnoses were made and procedures performed, which were recorded by the study investigator. Paramedics completed a pre-survey and post-survey.
Thirty paramedics were randomized to the control group; 30 paramedics were randomized to the US intervention group. Most paramedics had not received prior US training, had not previously performed a POCUS exam, and were uncomfortable with POCUS. Point-of-care US use was significantly higher in the US intervention group for both simulation cases (P <.001). A higher percentage of paramedics in the US intervention group arrived at the correct diagnosis (77%) for the TPTX case as compared to the control group (57%), although this difference was not significantly different (P = 0.1). There was no difference in the correct diagnosis between the control and US intervention groups for the undifferentiated shock case. On the post-survey, more paramedics in the US intervention group were comfortable with POCUS for evaluation of the lung and comfortable decompressing TPTX using POCUS (P <.001). Paramedics reported POCUS was within their scope of practice.
Despite being novice POCUS users, the paramedics were more likely to correctly diagnose TPTX during simulation after a brief POCUS educational intervention. However, this difference was not statistically significant. Paramedics were comfortable using POCUS and felt its use improved their TPTX diagnostic skills.
The effects of low and high frequency ultrasound on the production of volatile compounds along with their derivation and corresponding off-flavours in milk and milk products are discussed in this review. The review will simultaneously discuss possible mechanisms of applied ultrasound and their respective chemical and physical effects on milk components in relation to the production of volatile compounds. Ultrasound offers potential benefits in dairy applications over conventional heat treatment processes. Physical effects enhance the positive alteration of the physicochemical properties of milk proteins and fat. However, chemical effects propagated by free radical generation cause redox oxidations which in turn produce undesirable volatile compounds such as aldehydes, ketones, acids, esters, alcohols and sulphur, producing off-flavours. The extent of volatile compounds produced depends on ultrasonic processing conditions such as sonication time, temperature and frequency. Low frequency ultrasound limits free radical formation and results in few volatile compounds, while high ultrasonic frequency induces greater level of free radical formation. Furthermore, the compositional variations in terms of milk proteins and fat within the milk systems influence the production of volatile compounds. These factors could be controlled and optimized to reduce the production of undesirable volatiles, eliminate off-flavours, and promote the application of ultrasound technology in the dairy field.
Prehospital use of lung ultrasound (LUS) by paramedics to guide the diagnoses and treatment of patients has expanded over the past several years. However, almost all of this education has occurred in a classroom or hospital setting. No published prehospital use of LUS simulation software within an ambulance currently exists.
The objective of this study was to determine if various ambulance driving conditions (stationary, constant acceleration, serpentine, and start-stop) would impact paramedics’ abilities to perform LUS on a standardized patient (SP) using breath-holding to simulate lung pathology, or to perform LUS using ultrasound (US) simulation software. Primary endpoints included the participating paramedics’: (1) time to acquiring a satisfactory simulated LUS image; and (2) accuracy of image recognition and interpretation. Secondary endpoints for the breath-holding portion included: (1) the agreement between image interpretation by paramedic versus blinded expert reviewers; and (2) the quality of captured LUS image as determined by two blinded expert reviewers. Finally, a paramedic LUS training session was evaluated by comparing pre-test to post-test scores on a 25-item assessment requiring the recognition of a clinical interpretation of prerecorded LUS images.
Seventeen paramedics received a 45-minute LUS lecture. They then performed 25 LUS exams on both SPs and using simulation software, in each case looking for lung sliding, A and B lines, and seashore or barcode signs. Pre- and post-training, they completed a 25-question test consisting of still images and videos requiring pathology recognition and formulation of a clinical diagnosis. Sixteen paramedics performed the same exams in an ambulance during different driving conditions (stationary, constant acceleration, serpentines, and abrupt start-stops). Lung pathology was block randomized based on driving condition.
Paramedics demonstrated improved post-test scores compared to pre-test scores (P <.001). No significant difference existed across driving conditions for: time needed to obtain a simulated image; clinical interpretation of simulated LUS images; quality of saved images; or agreement of image interpretation between paramedics and blinded emergency physicians (EPs). Image acquisition time while parked was significantly greater than while the ambulance was driving in serpentines (Z = -2.898; P = .008). Technical challenges for both simulation techniques were noted.
Paramedics can correctly acquire and interpret simulated LUS images during different ambulance driving conditions. However, simulation techniques better adapted to this unique work environment are needed.