Clinton Kakazu

Pre-operative regional block anesthesia enhances operative strategy for arteriovenous fistula creation

Purpose We aim to assess the effect of regional block anesthesia on vein diameter, type of AVF placement, and fistula size and flow volume. Methods 30 patients presenting for AV access procedures were followed prospectively. Vein diameters via venous ultrasound and planned location for AV access were documented. Supraclavicular brachial plexus block was followed by repeat ultrasound and alterations in operative plan were noted. Patients returned to clinic for duplex ultrasound assessment. Results Average increase from baseline vein diameter with regional block was most pronounced in the lower cephalic (34%), upper cephalic (24.2%), and basilic veins (31.3%) and less in the brachial vein (8.7%). Type of AVF was modified following regional block in 14%. The rate of native AVF placement improved from 89% to 93% with regional block. Twenty-three AVF patients were available for follow-up (mean 24 weeks). Average fistula size was 7.9 mm (CI 6.9–8.9) and all patent fistulas developed flow volume >600 mL/min. Primary patency was attained in 83%. One thrombosis occurred after a basilic artery was lacerated during dialysis access. The average fistula increased 0.33 cm from post-block diameter (SD 0.22, P<.05). Conclusions Vein diameter increases significantly in the basilic and cephalic veins following regional block anesthesia and may improve the rate of native fistula placement. Propensity to dilate after regional block anesthesia does not predict size of the fistula.

In the new era of ultrasound guidance: is pneumothorax from supraclavicular block a rare complication of the past?

Editor—Before the utilization of ultrasound, the complication of pneumothorax was a concern for many anaesthetists performing supraclavicular block (SCB). 2 Technological advances have made ultrasound guidance for regional nerve blocks a standard practice, and when coupled with SCB, have rendered pneumothorax an improbable complication. The incidence of clinicallysignificant pneumothoraxafteran ultrasound-guided SCB has not yet been determined in a large patient study. Therefore, we undertook a 5 yr retrospective study to determine: (i) incidence of pneumothorax as a complication of ultrasound-guided SCB and (ii) the reliability of ultrasound in preventing pneumothoraces in SCB. After IRB approval, we analysed data from June 2009 to December 2013 on all brachial plexus blocks performed at Harbor-UCLA Medical Center. These data were obtained from our electronic health record database (Fig. 1). All SCB were examined for the presence or absence of ultrasound utilization and the complication of pneumothorax. Recorded pneumothorax incidence was zero. All SCB procedures were performed under ultrasound guidance. To determine if the difference in pneumothorax incidence with the utilization of ultrasound was statistically significant from the incidence without the utilization of ultrasound, a x test was performed between our data and the data from the literature. Thompson’s report (0.8% incidence) without ultrasound for SCB was chosen for x test comparison since it was the largest study (n1⁄41248). x analysis returned a P-value of ,0.001. This comparison demonstrates that ultrasoundguided SCB allowed statistically significant reductions in the incidence of pneumothorax. Althoughthese twostudies aretheoretically incomparable because the groups were not randomized, both featured the largest sample sizes of SCBs and lowest incidence of pneumothorax. While assumption of variation in technique, needle insertion, method of injection, and operator’s experience level were different between these studies, ultrasound guidance was the only constant variable, implying proper use of ultrasound guidance is the largest factor in improving patient safety from a pneumothorax. With our study being the largest to date with 1419 patients without pneumothorax, similar conclusions can be inferred cumulatively from other studies utilizing ultrasound without pneumothorax. On the contrary, isolated case reports of pneumothorax as a complication of ultrasound-guided SCB show that the true incidence of pneumothorax is not zero, despite its zero incidence at our institution. Although our study and others have been able to obtain a zero rate of occurrence of pneumothorax, this does not imply zero risk of clinically relevant pneumothorax nor does it imply any information about the size of the risk. Hanley’s mathematical ‘rule of three’ provides a method of calculating theoretical maximum long-run risk with a 95% confidence interval, yielding a theoretical risk of 2:1000 of developing pneumothorax with ultrasound-guided SCB. Our 5 yr study shows that SCB are our preferred technique of regional anaesthesia for upper extremity surgery. SCB accounted for 72% of all brachial plexus blocks (Fig. 1), from which we can infer that the majority of upper extremity blocks are performed without fear of pneumothorax complications. At our teaching institution, ultrasound has been a routine practice since 2007, with faculty involvement in 100% of SCBs.

Hemodynamics with propofol: is propofol dangerous in classes III-V patients?

rial oxygen saturation 100%). The surgical procedure was performed uneventfully. Postoperative Spo2 values ranged 82%–89%. Further investigation into the family tree revealed a 5-yr-old brother with a room air Spo2 value of 76%, a 27-yr-old father with room air Spo2 of 61%–62% and a paternal grandfather with room air Spo2 of 80%–82%. Results of hemoglobin electrophoresis showed an abnormal hemoglobin variant, known as hemoglobin Cheverly (Table 1). In summary, a pulse oximeter is not an accurate monitor for patients with unstable hemoglobin Cheverly and possibly other hemoglobinopathies (2,3).

Stellate ganglion block for postoperative analgesia in patients with upper extremity orthopaedic injuries

htm;jsessionid=2DD4749FA 5D7C11DE1DEA1A63DD04D17? year=2005&index=11&absnum= 1575 (accessed 20 ⁄ 08 ⁄ 2011). 4 Bantel C, Trapp S. The role of the autonomic nervous system in acute surgical pain processing – what do we know? Anaesthesia 2011; 66:

Bone cement implantation syndrome affecting operating room personnel

J Anaesth 2014; 113: 800–6 2. Herrenbruck T, Erickson EW, Damron TA, Heiner J. Adverse Clinical events during cemented long-stem femoral arthroplasty. Clin Orthop Relat Res 2002; 395: 154–63 3. McCaskie AW, Barnes MR, Lin E, Harper WM, Gregg PJ. Cement pressurization during hip replacement. J Bone Joint Surg 1997; 79: 379–84 4. Donaldson AJ, Thomson HE, Harper NJ, Kenny NW. Bone cement implantation syndrome. Br J Anaesth 2009; 102: 12–22

Are we ready for non-invasive blood pressure monitoring?

Editor—We read the recent articles dealing with a new non-invasive blood pressure (BP) monitoring device called ‘Nexfin’. The article by Vos and colleagues compares a ‘finger’ BP attachment with a radial artery catheter (A-line), which is the ‘gold standard’, when anaesthesia providers are taking care of high-risk patients. Their results showed a bias using a statistical analysis against the Nexfin device. Nexfin may not be superior, even if not ‘inferior’, as the author’s point out, especially on afinger. In reading further within the issue, there is another article dealing with the Nexfin device.Weiss and colleagues also compared theNexfin device to a radial artery catheter (A-line). The author’s also found a ‘bias’ and concluded that the Nexfin device is not interchangeable with invasive monitoring and may be used to detect variations in blood pressure. The two articles in the journal truly show us that the Nexfin device is not perfected as yet and anaesthesia providers should refrain from using the non-invasive device. In patients with stable haemodynamic parameters, an upper arm BP cuff is still theway to go. For decades, non-invasive blood pressure cuffs have been used in most patients and invasive arterial catheters in high-risk patients. These are the ‘gold standards’ in anaesthesiology practice. Another study by Schumann and colleagues showed good correlation between the new non-invasive BP device and the A-line in a series of morbidly obese patients (mean BMI 48 kg m). They also found a statistical bias compared with an A-line. They suggested that the differences in pulse pressure variation between the invasive and non-invasive approaches likely reflect the specific technologies and algorithms used by each monitor. When a patient’s instability overwhelms noninvasive technology and algorithms, they become largely unreliable, and an invasive A-line is still the gold standard. Kim and colleagues also found ‘bias’ when comparing continuous non-invasive BP monitoring with invasive monitoring in a meta-analysis. As the artery is much smaller at the finger level, the pulse oximeter’s waveform can tell you the quality of the pulse.When the patient takes a deep breath, it affects the venous return to the heart, which changes the volume of the pulse and the size of the trace. This may serve as an early warning system of the patient’s volume status. Most of these authors have found bias when using the Nexfin device. Its use should be limited as an adjunct to monitor variations and patterns rather than as a true estimation of BP.

Enhanced visual clarity of intimal tear using real-time 3D transesophageal echocardiography during TEVAR of a type B dissection.

A relatively new technological advancement to enhance visual clarity during thoracic endovascular aortic repair (TEVAR) is demonstrated in a 76-year-old man being treated for a type B dissection (Figure, A,B). While surgical access to the left common femoral artery was obtained, a real-time 3-dimensional transesophageal echocardiogram (RT 3D TEE) was used to evaluate the entire thoracic aorta (model iE33; Phillips Healthcare, Andover, MA, USA). The RT 3D TEE (Figure, C) revealed a dissection within the descending thoracic aorta not seen on preoperative computed tomographic angiography (CTA). An intraoperative aortogram (Figure, D) showed an aneurysm ~10 cm below the origin the left subclavian artery, with no filling defect. During intravascular ultrasound (IVUS) measurement for stent selection (Figure, E), a partially thrombosed localized dissection was incidentally discovered, which corresponded with the RT 3D TEE. At the completion of the procedure, the RT 3D TEE confirmed stentgraft exclusion of the aneurysmal segment and the intimal tear with no endoleak.

Acute ascending aortic intramural hematoma as a complication of the endovascular repair of a Type B aortic dissection

Endovascular aortic graft repair (EVAR) for patients with Type B aortic dissection is a less invasive surgical procedure (compared to traditional open surgical repair) that is associated with less morbidity and shortened recovery times. However, there are notable complications for the patients undergoing EVAR. We report a patient who was brought to our hospital with a Type B dissection and underwent a thoracic EVAR but suffered iatrogenic aortic injury resulting in cardiac tamponade. This case study highlights the importance of intraoperative transesophageal echocardiography to facilitate early detection of possible EVAR complications.

Theatre team contracts multiple syndromes as a result of bone cement

Editor—We readwith interest the recent editorial by Griffiths and Parker published in the January 2015 issue of the BJA, which deals with bone cement implantation syndrome during surgery for proximal femur neck fractures. Their editorial concerns an article written by Olsen and colleagues entitled, ‘Bone cement implantation syndrome in cemented hemiarthroplasty for femoral neck fracture: incidence, risk factors, and effect on outcome’. The editorial mostly states the rate of the syndrome in Europe and towhat extent patients respond to the cement during surgery and postoperatively depending on their physical status (ASA class). They correctly state that not only surgeons should be aware of bone cement adverse events, but also, anaesthetists and the theatre team (i.e. nurses, technicians). If the syndrome is prevalent in Europe (Northern countries), are the same occurrences happening in other parts of Southern Europe and the world? Does the syndrome affect more males than females? Does ethnicity have a major implication for patients to develop the syndrome? Although the patient’s physical ASA status has major implications for its development, patients from other countries may not manifest adverse effects as the people from Northern Europe and the UK. We would like to suggest to the editorial authors the following aspects of the implantation syndrome that can also affect the operating and theatre teams in ‘Multiple syndromes’ (http://www. cdph.ca.gov/programs/hesis/Documents/mma.pdf) such as:

Making bisoprolol a perioperative agent.

1 Mahjoub Y, Lejeune V, Muller L, et al. Evaluation of pulse pressure variationvaliditycriteria incritically ill patients: a prospective observational multicentre point-prevalence study. Br J Anaesth 2014; 112: 681–5 2 Futier E, Constantin JM, Paugam-Burtz C, et al. A trial of intraoperative low-tidal-volume ventilation in abdominal surgery. N Engl J Med 2013; 369: 428–37 3 De Backer D, Heenen S, Piagnerelli M, Koch M, Vincent JL. Pulse pressure variations to predict fluid responsiveness: influence of tidal volume. Intensive Care Med 2005; 31: 517–23 4 Duperret S, Lhuillier F, Piriou V, et al. Increased intra-abdominal pressure affects respiratory variations in arterial pressure in normovolaemic and hypovolemic mechanically ventilated healthy pigs. Intensive Care Med 2007; 33: 163–71 5 De Waal EE, Rex S, Kruitwagen CL, et al. Dynamic preload indicators fail to predict fluid responsiveness in open-chest conditions. Crit Care Med 2009; 37: 510–5