Efficacy of interspace between the popliteal artery and the capsule of the posterior knee (iPACK) block versus periarticular local infiltration analgesia after unilateral total knee arthroplasty: Prospective randomized control trial.

OBJECTIVES: To compare the efficacy of interspace between the popliteal artery and the capsule of the posterior knee (iPACK) block with periarticular local infiltration analgesia (LIA) to assess postoperative pain control and enhanced recovery after total knee arthroplasty (TKA). METHODS: This research was carried out at King Saud University Medical City, Riyadh, Saudi Arabia, from September 2020 to March 2021. Eighty Patients scheduled for elective unilateral TKA were randomized to receive either iPACK or periarticular LIA along with adductor canal block under spinal anesthesia. The primary outcome was postoperative pain score, and secondary outcomes included physical rehabilitation, duration of surgery, length of post-anesthesia care unit stay, hemodynamics, and length of hospital stay. RESULTS: The pain score during activity in iPACK group was significantly lower compared to LIA group at 4 hours postoperatively, but no significant difference was observed at 24 or 48 hours. The timed up and go test took significantly longer for patients in LIA group at 4, 24, and 48 hours compared to those in iPACK group. No significant differences in knee range of motion were observed between the 2 groups at any point. CONCLUSION: Based on our findings, iPACK block is an effective technique in reducing pain in the immediate postoperative period without affecting motor function, resulting in enhanced recovery following primary TKA.

In vivo assessment of spinal cord elasticity using shear wave ultrasound in dogs.

OBJECTIVE: Evaluation of living tissue elasticity has wide applications in disease characterization and prognosis prediction. Few previous ex vivo attempts have been made to characterize spinal cord elasticity (SCE). Recently, tissue elasticity assessment has been clinically feasible using ultrasound shear wave elastography (SWE). The current study aims to characterize SCE in healthy dogs, in vivo, utilizing SWE, and to address SCE changes during compression. METHODS: Ten Greyhound dogs (mean age 14 months; mean weight 14.3 kg) were anesthetized and tracheally intubated, with hemodynamic and neurological monitoring. A 3-level, midcervical laminectomy was performed. SCE was assessed at baseline. Next, 8- and 13-mm balloon compressions were sequentially applied ventral to the spinal cord. RESULTS: The mean SCE was 18.5 ± 7 kPa. Elasticity of the central canal, pia mater, and dura mater were 21.7 ± 9.6 kPa, 26.1 ± 14.8 kPa, and 63.2 ± 11.5 kPa, respectively. As expected, the spinal cord demonstrated less elasticity than the dura mater (p < 0.0001) and pia mater (trend toward significance p = 0.08). Notably, the 13-mm balloon compression resulted in a stiffer spinal cord than at baseline (233 ± 73 kPa versus 18.5 ± 7 kPa, p < 0.0001) and 8-mm balloon compression (233 ± 73 kPa versus 185 ± 68 kPa, p < 0.048). CONCLUSIONS: In vivo SCE evaluation using SWE is feasible and comparable to earlier reports, as demonstrated by physical sectioning of the spinal cord. The compressed spinal cord is stiffer than a free spinal cord, with a linear increase in SCE with increasing mechanical compression. Knowledge of the biomechanical properties of the spinal cord including SCE has potential implications for disease management and prognosis.

Intraoperative Nerve Stimulation During Brachial Plexus Surgery: Comparison Between a Totally Disposable Nerve Stimulator and Nerve Stimulator Normally Used for Nerve Blocks.

BACKGROUND: Intraoperative nerve stimulation is done routinely in brachial plexus and peripheral nerve surgery as well as in selective neurectomy in spastic patients. OBJECTIVE: The current study compares the use of 2 different devices for nerve stimulation: a totally disposable nerve stimulator and a nerve stimulator used for nerve blocks by anesthetists. METHODS: A retrospective study of 60 patients who underwent brachial plexus surgery: In 30 patients, we used the totally disposable nerve stimulator (group 1) and in another 30 patients, we used the anesthesia device (group 2). The cost of disposable materials used for nerve stimulation was calculated in each group. The same surgeon performed all operations, and he was asked to give his subjective opinion regarding the convenience and ease of use of the device in each group. RESULTS: The main advantages of the totally disposable device are its placement totally within the sterile field, and it is operated by the surgeon without the need to communicate with the anesthetist. However, the totally disposable device had several major disadvantages when compared to the anesthesia device. Firstly, the disposable stimulator can only deliver 0.5, 1.0, and 2.0 mA stimuli, while the anesthesia device can deliver stimuli of 0.1 to 5 mA (in 0.1 mA increments). Secondly, the disposable stimulator frequently fails to operate during surgery, and this is not experienced with the anesthesia device. Finally, the cost of disposables is less using the anesthesia device. CONCLUSION: Our center has stopped using the disposable nerve stimulator in favour for the anesthesia device.

HISTORIQUE: La stimulation nerveuse intraopératoire est utilisée régulièrement lors d'opérations du plexus brachial et des nerfs périphériques, de même que lors de neurectomies sélectives chez les patients spastiques. OBJECTIF: La présente étude visait à comparer deux dispositifs différents pour la stimulation nerveuse, soit un stimulateur nerveux entièrement jetable et un stimulateur nerveux qu'utilisent les anesthésistes pour les blocages nerveux. MÉTHODOLOGIE: Les chercheurs ont effectué une étude rétrospective auprès de 60 patients qui avaient subi une opération du plexus brachial. Chez 30 patients, ils ont utilisé le stimulateur nerveux entièrement jetable (groupe I) et chez 30 autres, le dispositif d'anesthésie (groupe II). Les chercheurs ont calculé le coût des fournitures jetables utilisées pour la stimulation nerveuse dans chaque groupe. Le même chirurgien a effectué toutes les opérations et a été invité à donner son avis subjectif sur le caractère pratique et la facilité d'utilisation du dispositif dans chaque groupe. RÉSULTATS: Les dispositifs complètement jetables ont comme principaux avantages de se situer entièrement dans le champ stérile et d'être utilisés par le chirurgien sans qu'il communique avec l'anesthésiste. Cependant, ils comportent plusieurs désavantages par rapport au dispositif d'anesthésie. D'abord, ils peuvent seulement délivrer un stimulus de 0,5 mA, 1,0 mA et 2,0 mA, alors que les dispositifs d'anesthésie en délivrent de 0,1 mA à 5 mA (par incréments de 0,1 mA). Ensuite, le stimulateur jetable est souvent défaillant pendant la chirurgie, ce qui ne se produit pas avec le dispositif d'anesthésie. Enfin, le dispositif d'anesthésie réduit le coût des fournitures jetables. CONCLUSION: Le centre des chercheurs a cessé d'utiliser le stimulateur nerveux jetable au profit du dispositif d'anesthésie.

Using fentanyl and propofol for tracheal intubation during sevoflurane induction without muscle relaxants in children: A randomized prospective study.

CONTEXT: Tracheal intubation is frequently facilitated with sevoflurane induction without the use of muscle relaxants in children. AIM: The aim of this study was to compare the effects of two different doses of propofol preceded by a fixed dose of fentanyl during sevoflurane induction on quality of tracheal intubation in children. SETTINGS AND DESIGN: This was a prospective randomized study. SUBJECTS AND METHODS: Ninety American Society of Anesthesiologists I-II children aged 2-6 years were randomly assigned to one of two equal groups to receive 2 µg/kg of fentanyl with 2 mg/kg of propofol (Group I) or 2 µg/kg of fentanyl with 3 mg/kg of propofol (Group II) during sevoflurane induction. The intubating conditions and hemodynamic responses were evaluated. The time from sevoflurane induction to loss of consciousness, to intravenous line insertion, and to intubation was measured. The occurrence of any adverse effect was recorded. STATISTICAL ANALYSIS USED: Results were analyzed using Student's t-test, paired t-test, and Chi-square test. P < 0.05 was considered statistically significant. RESULTS: The incidence of excellent intubating conditions was achieved more significantly in Group II (41/45 patients, 91%) than that in Group I (31/45 patients, 69%) (P = 0.008) (95% confidence interval [CI] =0.39-0.8). Whereas, there were no significant differences between the two groups in terms of the overall acceptable intubating conditions in Group I (40/45 patients, 89%) and Group II (43/45 patients, 96%) (P = 0.81) (95% CI = 0.71-1.31). No patient developed any adverse effect. CONCLUSION: The administration of 3 mg/kg propofol preceded by 2 µg/kg fentanyl provided a higher proportion of excellent intubating conditions compared with 2 mg/kg propofol preceded by 2 µg/kg fentanyl during sevoflurane induction in children without muscle relaxants.

Pain relief following thoracic surgical procedures: A literature review of the uncommon techniques.

Thoracic surgical procedures can be either thoracotomy or thoracoscopy. In thoracotomy, the incision could be either muscle-cutting or muscle-sparing incision. The posterolateral thoracotomy incision is used for most general thoracic surgical procedures. This incision, which involves division of the latissimus dorsi and serratus anterior muscles, affords excellent exposure of the thoracic cavity. However, it is associated with significant morbidity, including impaired pulmonary function, postoperative chest pain, and restricted arm and shoulder movement. Various muscle-sparing incisions have been proposed to decrease the morbidity. Postthoracotomy pain originates from pleural and muscular damage, costovertebral joint disruption, and intercostal nerve damage during surgery. Inadequate pain relief after surgery affects the quality of patient's recovery and exposes the patients to postoperative morbidities. There is a tendency nowadays among thoracic surgeons and anesthesiologists toward the area of enhanced recovery after thoracic surgery which requires careful titration of the anesthetic drugs in awake patients undergoing thoracoscopic procedures. There is a common feeling among thoracic anesthesiologists that potthoracoscopy procedures produce less pain intensity versus thoracotomy which is partially true. However, effective management of acute pain following either thoracotomy/thoracoscopy is needed and may prevent these complications and reduce the likelihood of developing chronic pain. In this report, we are going to review the newly introduced postthoracotomy/thoracoscopy pain relief modalities with special reference to the new tendency of awake thoracic surgical procedures and its impact on enhanced recovery after surgery.

Ambu AuraOnce versus i-gel laryngeal mask airway in infants and children undergoing surgical procedures. A randomized controlled trial.

OBJECTIVES: To compare the efficacy and performance of the pediatric Ambu AuraOnce (Ambu AO) mask (Ambu, Copenhagen, Denmark) and i-gel mask (Intersurgical Ltd., Wokingham, United Kingdom). Methods: From May 2015 to September 2016, 112 patients, 0-14 years old, underwent elective surgery at a tertiary university hospital (Riyadh, Saudi Arabia). They were randomly assigned to the Ambu AO or i-gel group. Three groups underwent a subgroup analysis: ≤5 kg (group 1), 5.1-10.0 kg (group 2), and >10 kg (group 3). Results: The oropharyngeal leak pressure was significantly higher for the i-gel (25.4±4.1 cm H2O) than for the Ambu AO (22.5±3.9 cm H2O, p less than 0.001). The Ambu AO had a slightly higher ease of insertion compared to the i-gel (100% versus 94%, p=0.08)  and required less manipulation (2% versus 11%, p=0.07).The Ambu AO and i-gel showed non-significant differences in performance between weight groups. There were statistically significant differences for higher leak pressure in group 2 (p=0.01) and group 3 (p=0.002) in favor of the i-gel, and for less manipulation in the Ambu AO in group 1 (p=0.04). Fiberoptic viewing was superior in group 2 for the i-gel (p=0.03) and in group 3 for the Ambu AO (p=0.02). Conclusion: Both devices demonstrated equally good performance with low morbidity. The Ambu AO had a statistical tendency towards easier insertion and less manipulation. Confirming this finding will require large scale trials.

Spatial relationship of i-gel® and Ambu® AuraOnceTM on pediatric airway: a randomized comparison based on three dimensional magnetic resonance imaging.

BACKGROUND: Gross morphological differences exist among different brands of pediatric supraglottic devices (SGDs). The aim of this study is to compare the spatial relationship of i-gel® and Ambu® AuraOnce (AO)TM on pediatric airway based on three dimensional (3-D) magnetic resonance imaging (MRI) measurements. METHODS: Sixty patients up to 12 years of age were enrolled and assigned in two groups, i-gel® or Ambu® AOTM. After confirmation of proper placement of these SGDs, 3-D MRI scans of head and neck were performed. Another native scan was also obtained after removal of the SGD for comparison. RESULTS: i-gel® produced significant degree of compression of the tongue (P<0.001) while Ambu® AOTM significantly reduced the axial diameter of glottis (P=0.033) compared to their native values. Both i-gel® and Ambu® AOTM significantly reduced the area of the glottic opening (P<0.001 for each device) and the distance between the arytenoids (P<0.001 and P=0.007 respectively); and increased the distance between the hyoid bone and cervical spine (P<0.001 and P=0.001 respectively) in comparison to their corresponding native values. Bowl of i-gel® produced greater dilation of the upper esophageal sphincter at all levels of measurement- upper (P<0.001), middle (P=0.001) and lower (P=0.015) in comparison to Ambu® AOTM. CONCLUSIONS: Based on 3-D MRI measurements done on living patients, both SGDs distorted the anatomy of pediatric airway compared to their respective native values to variable extent. The relevance of these effects needs further studies on larger patient group in order to reduce morbidity on pediatric airway.

Near miss in a patient with undiagnosed Brugada syndrome: a case report and literature review.

Brugada syndrome is a rare genetic disorder mostly affecting young subjects without any underlying heart disease. Here we are describing 1 patient presented for gastric bypass surgery who had near cardiac arrest under general anesthesia for unknown reason. Postoperative investigation of this case revealed the diagnosis of Brugada syndrome.

Routine Use of Glidescope and Macintosh Laryngoscope by Trainee Anesthetists.

OBJECTIVE: To compare intubating conditions, success rate, and ease of intubation by anesthesia trainees using Glidescope Videolaryngoscope (GVL) compared to Macintosh laryngoscope (MCL). STUDY DESIGN: Comparative study. PLACE AND DURATION OF STUDY: King Khalid University Hospital, Riyadh, Saudi Arabia, from January 2012 to February 2015. METHODOLOGY: Eighty adult patients ASAI and II with normal airway, scheduled to undergo elective surgery requiring endotracheal (ET) intubation were enrolled. Patients were randomly divided into 2 groups: GVL and MCL. All intubations were performed by trainee residents having experience of more than 1 year and who had successfully performed more than 50 tracheal intubations with each device. Glottic view based on Cormack and Lehane&#039;s (C&amp;L&#039;s) score and percentage of glottis opening (POGO) score, time to successful intubation, need of external pressure, and overall difficulty scores were compared using either GVL or MCL. RESULTS: View of glottis based on C&amp;L&#039;s classification was better (p &lt; 0.001) and POGO score was higher (88.25 &plusmn;22.06 vs. 57.25 &plusmn;29.26, p &lt; 0.001) with GVL compared to MCL. Time to intubate in seconds was (32.90 &plusmn;8.69 vs. 41.33 &plusmn;15.29, p = 0.004) and overall difficulty score was less 2.78 &plusmn;1.39 vs. 4.85 &plusmn;1.75 (p &lt; 0.001) using GVL compared to MCL. CONCLUSION: Residents found ET intubation to be faster and easier with superior glottic view using GVL compared to MCL in patients with normal airway.

Parker Flex-It stylet is as effective as GlideRite Rigid stylet for orotracheal intubation by Glidescope.

OBJECTIVES: To evaluate Parker Flex-It stylet as an alternative to GlideRite Rigid stylet to aid tracheal intubation with the Glidescope.  METHODS: This prospective randomized trial was conducted at King Abdulaziz University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia between May and December 2014. Sixty American Society of Anesthesiologists I-II patients were randomly assigned to one of 2 equal groups receiving intubation by Glidescope using either  GlideRite Rigid stylet (Group GS) or Parker Flex-It stylet (Group PS). The total intubation time, ease of intubation, incidences of successful intubation at first attempt, number of intubation attempts, use of optimization maneuvers, and possible complications were recorded.   RESULTS: No significant differences between both groups regarding the total intubation time (p=0.08) was observed. Intubation was significantly easier in group PS compared with group GS as measured by visual analogue scale (p=0.001) with no significant differences between the groups regarding the rate of successful tracheal intubation from first attempt (p=0.524). However, the number of attempts at intubation and usage of external laryngeal manipulation were similar in both groups (p greater than 0.05). The incidence of sore throat, dysphagia, hoarseness, and trauma were significantly higher in group GS (p less than 0.05).  CONCLUSION: Parker Flex-It stylet is as effective as GlideRite Rigid stylet when used by experienced operators in patients with normal airways using Glidescope; however, it is easier and less traumatic.

Ultrasound imaging accurately identifies the intercostobrachial nerve.

OBJECTIVE: To test the hypothesis that identification and blockade of the intercostobrachial nerve (ICBN) can be achieved under ultrasound (US) guidance using a small volume of local anesthetic. METHODS: Twenty-eight adult male volunteers were examined at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from November 2012 to September 2013. Intercostobrachial nerve blockade was performed using one ml of 2% lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head. RESULTS: The ICBN appears as a hyper-echoic structure. The nerve diameter was 2.3±0.28 mm, and the depth was 9±0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3±1.6 cm anteriorly; 6.2±2.9 cm posteriorly; 9.4±2.9 cm proximally; and 9.2±4.4 cm distally. Intercostobrachial nerve blockade using one ml of local anesthetic was successful in all cases. CONCLUSION: The present study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade.

Flying blind in anesthesia: A safety concern.

We describe two cases of sudden loss of display of all the monitors of Zeus anesthesia work station during operation, which is a major safety concern. Flying blind in anesthesia could be devastating. These cases attempt to highlight the need for greater vigilance by anesthesiologists and have implications for improvement in technology.

Common carotid artery surprise during percutaneous dilatational tracheostomy - A near miss, confirmed with ultrasound.

The practice of percutaneous dilatational tracheostomy (PDT) has gained popularity and acceptance due to the ease in acquiring its skill and low probability of complications. Nevertheless, PDT is associated with a few complications, some really life-threatening. We present a case of an abnormally located common carotid artery encountered during PDT in our intensive care unit. The procedure was electively posted, in an old patient chronically ventilated after a revived cardiac arrest. While identifying the landmarks on palpation pulsation was felt similar to arterial pulsation. This was confirmed using bedside portable ultrasonography and found to be the right common carotid artery forming a loop anterior to the trachea at the level of the third and fourth tracheal rings. The patient had a past history of thyroidectomy and this was suspected to be the primary reason for the altered course of the right common carotid artery.

Ultrasound gel-nerve contact: an experimental animal histologic study.

BACKGROUND: Ultrasound (US) regional nerve block requires the use of gel applied over the skin. With subsequent needle insertion, some of the gel may adhere either on the shaft or within the needle lumen and may be carried to the perineural structures or intraneurally. We performed this experimental animal study to investigate the effects of US gel contact on the nerve histologic structure. METHODS: Nine male beagle dogs were studied. Dogs 1 to 3 were the control group and dogs 4 to 9 were the study group. Bilateral posterior tibial nerves were dissected and exposed for the control group. Nerve specimens were obtained for histologic examination immediately for the first dog, at 24 hours for the second dog, and at 48 hours for the third dog followed by wound closure. For the study group, bilateral posterior tibial nerves were exposed, and 2 mL US gel was applied locally directly on the nerve, followed by wound closure. Nerve specimens were excised at 24 hours from one side and at 48 hours from the other side. Nerve specimens were examined by a neuropathologist for evidence of nerve inflammation. RESULTS: The control nerve specimens showed no significant pathology. Nerve specimens of the study group at the end of 24 hours of gel-nerve contact showed mild focal perineural inflammatory changes with clusters of polymorph leukocytes. At 48 hours, perineural moderate inflammatory changes with clusters of lymphocytes and macrophages were demonstrated in 2 animals. Long-term neurologic deficit in the form of limping was observed for all dogs. CONCLUSION: Histologic features after perineural exposure to US gel are rather nonspecific and likely of no clinical significance. However, further studies are needed to determine the effect of US gel injection on intraneural tissues.