Cricothyroidotomy catheters: an investigation of mechanisms of failure and the effect of a novel intracatheter stylet.

Emergency catheter cricothyroidotomy often fails. Case reports have concentrated on kinking and displacement of the catheter as the major causes. We investigated catheter tip penetration of the trachea. Using insertion angles of 90°, 75°, 60°, 45° and 30° we advanced 14 G intravenous catheters into fresh isolated sheep tracheas during high pressure oxygen insufflation. At all angles, the catheter tip became blocked by pushing into the mucosa with submucosal gas injection on one or more attempts. Full thickness rupture with extratracheal gas also occurred on insertions at 90° and 60°. We then tested a Luer-mounted prototype wire stylet which remains in situ during insufflation. Using the same methodology, the stylet was able to be placed and prevented blockage at all angles of insertion. Mucosal trauma and submucosal gas injection occurred on insertions at 90° and 75°. Our results should guide further stylet design.

Report from the 17th Annual Western Canadian Gastrointestinal Cancer Consensus Conference; Edmonton, Alberta; 11-12 September 2015.

The 17th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Edmonton, Alberta, 11-12 September 2015. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of gastric cancer.

Consensus statement: the 16th Annual Western Canadian Gastrointestinal Cancer Consensus Conference; Saskatoon, Saskatchewan; September 5-6, 2014.

The 16th annual Western Canadian Gastrointestinal Cancer Consensus Conference was held in Saskatoon, Saskatchewan, September 4-5, 2014. The Consensus Conference is an interactive, multidisciplinary event attended by health care professionals from across western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) involved in the care of gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

Symptomatic local anaesthetic toxicity and plasma ropivacaine concentrations after transversus abdominis plane block for Caesarean section.

BACKGROUND: The transversus abdominis plane (TAP) block involves injecting a large volume of local anaesthetic between the muscles of the abdominal wall. Plasma concentrations of ropivacaine after gynaecological laparotomy are potentially high enough to result in systemic toxicity, and there are pharmacokinetic reasons why pregnancy may increase susceptibility to local anaesthetic toxicity. METHODS: Adult female patients (n=30) undergoing elective Caesarean section under spinal anaesthesia received bilateral ultrasound-guided TAP blocks after wound closure (2.5 mg kg(-1) of ropivacaine diluted to 40 ml). Venous blood samples were collected at 10, 20, 30, 45, 60, 90, 120, 180 and 240 min following the block. Blood samples were assayed for total and free ropivacaine concentrations. Patients were assessed for symptoms of local anaesthetic toxicity. RESULTS: The mean [standard deviation (SD)] peak total concentration of ropivacaine occurred at 30 min post-injection and was 1.82 (0.69) µg ml(-1). The maximum detected concentration in any patient was 3.76 µg ml(-1) (at 10 min post-injection). Three patients reported symptoms of mild neurotoxicity, and the mean (SD) peak levels were elevated in these patients, 2.70 (0.46) µg ml(-1). CONCLUSIONS: TAP blocks can result in elevated plasma ropivacaine concentrations in patients undergoing Caesarean section, which may be associated with neurotoxicity.

Ultrasound-guided supra-inguinal fascia iliaca block: a cadaveric evaluation of a novel approach.

Existing descriptions of ultrasound-guided fascia iliaca block focus on injection of local anaesthetic inferior to the inguinal ligament, relying on supra-inguinal spread to block the lateral femoral cutaneous nerve in the iliac fossa. In this study, we explored injectate spread and nerve involvement in a cadaveric dye-injection model, using a supra-inguinal ultrasound-guided technique that places local anaesthetic directly into the iliac fossa. Bilateral injections of 20 ml 0.25% aniline blue dye were made in six unembalmed cadavers. The femoral nerve was stained by the dye in all twelve injections. The lateral femoral cutaneous nerve was stained bilaterally in five cadavers, but the nerve was absent on both sides in the sixth cadaver. The ilio-inguinal nerve passed into the iliac fossa over the iliacus muscle in eight of the hemi-pelvi and was stained in seven of these occasions. We have performed more than 150 blocks in patients using this approach without complications. Injection using this technique in cadavers leads to extensive fluid spread throughout the iliac fossa. In patients this approach may allow a lower volume block of the femoral nerve and lateral femoral cutaneous nerve while still injecting at a distance from the femoral nerve.

Plasma ropivacaine concentrations after ultrasound-guided transversus abdominis plane block.

BACKGROUND: The transversus abdominis plane block is a novel technique involving injection of local anaesthetic between the internal oblique and the transversus abdominis muscles of the abdominal wall. It is possible that injection of a large dose of local anaesthetic into a relatively vascular plane may result in toxic concentrations. One previously published study examined plasma lidocaine concentrations after transversus abdominus plane block and showed potentially toxic plasma concentrations. Although ropivacaine is most commonly used for this technique, plasma concentrations of ropivacaine after this block have not been reported previously. METHODS: Adult female patients undergoing elective open gynaecological surgery received bilateral ultrasound-guided transverse abdominal plane blocks before surgical incision (3 mg kg(-1) of ropivacaine diluted to 40 ml). Venous blood was collected each 15 min for the first hour, each 30 min for the second hour, and then at 3, 4, 12, and 24 h post-block. RESULTS: Twenty-eight patients were recruited. The mean (sd) peak total ropivacaine concentration occurred 30 min post-injection and was 2.54 (sd 0.75) µg ml(-1). The highest measured concentration was 4.00 µg ml(-1), also 30 min post-injection. Mean total concentrations remained above 2.20 µg ml(-1) for up to 90 min post-injection. The mean unbound peak venous concentration was 0.14 (0.05) µg ml(-1), and the peak was 0.25 µg ml(-1). CONCLUSIONS: Transversus abdominus plane block using 3 mg kg(-1) of ropivacaine produces venous plasma concentrations that are potentially neurotoxic, although broadly consistent with plasma levels found after injection at other comparable sites.

Canadian guidelines on the management of colorectal peritoneal metastases.

Modern management of colorectal cancer (crc) with peritoneal metastasis (pm) is based on a combination of cytoreductive surgery (crs), systemic chemotherapy, and hyperthermic intraperitoneal chemotherapy (hipec). Although the role of hipec has recently been questioned with respect to results from the prodige 7 trial, the role and benefit of a complete crs were confirmed, as observed with a 41-month gain in median survival in that study, and 15% of patients remaining disease-free at 5 years. Still, crc with pm is associated with a poor prognosis, and good patient selection is essential. Many questions about the optimal management approach for such patients remain, but all patients with pm from crc should be referred to, or discussed with, a pm surgical oncologist, because cure is possible. The objective of the present guideline is to offer a practical approach to the management of pm from crc and to reflect on the new practice standards set by recent publications on the topic.

Prophylactic total gastrectomy (PTG) for hereditary diffuse gastric cancer (HDGC): the Newfoundland experience with 23 patients.

BACKGROUND: Hereditary diffuse gastric cancer (HDGC) results from truncating mutations of the CDH1 (E-cadherin) gene. It is an autosomal dominant cancer susceptibility syndrome with a lifetime risk of diffuse gastric cancer (DGC) of 60-80%, with a mean age of onset of 37 years. There exists no adequate screening test for DGC. Early intramucosal diffuse/signet-ring cell carcinomas have been found in prophylactic total gastrectomy (PTG) specimens following normal preoperative endoscopy. Total gastrectomy has been advocated on a prophylactic basis. The aim of this study was to report our experience with PTG in 23 patients from the Canadian province of Newfoundland and Labrador. This is the largest series worldwide. METHODS: A retrospective study of consecutive patients undergoing PTG for HDGC was performed. All patients were confirmed to have a truncating mutation of the CDH1 gene. RESULTS: Twenty-three patients underwent PTG between February 2006 and November 2008. Major complications were found in 4/23 patients (17%), with no mortality. Two of 23 patients (9%) had positive mucosal biopsies on preoperative EGD. Twenty-two of 23 patients (96%) had evidence of diffuse/signet-ring carcinoma on final standardized pathological evaluation. Therefore, 21/23 (91%) were not picked up by preoperative EGD screening. CONCLUSIONS: PTG can be performed in patients with HDGC with a low rate of serious complications. Methods of reconstruction incorporating a pouch reservoir and preservation of the postgastric branches of the vagus nerves need to be explored. More refined penetrance estimates, effective screening protocols, and long-term psychological and functional outcomes following PTG require organized multicenter collaborative efforts.

Determination of spread of injectate after ultrasound-guided transversus abdominis plane block: a cadaveric study.

BACKGROUND: The transversus abdominis plane (TAP) block is a new regional anaesthesia technique that provides analgesia after abdominal surgery. It involves injection of local anaesthetic into the plane between the transversus abdominis and the internal oblique muscles. The TAP block can be performed using a landmark technique through the lumbar triangle or with ultrasound guidance. The goal of this anatomical study with dye injection into the TAP and subsequent cadaver dissections was to establish the likely spread of local anaesthesia in vivo and the segmental nerve involvement resulting from ultrasound-guided TAP block. METHODS: An ultrasound-guided injection of aniline dye into the TAP was performed for each hemi-abdominal wall of 10 unembalmed human cadavers and this was followed by dissection to determine the extent of dye spread and nerve involvement in the dye injection. RESULTS: After excluding one pilot specimen and one with advanced tissue decomposition, 16 hemi-abdominal walls were successfully injected and dissected. The lower thoracic nerves (T10-T12) and first lumbar nerve (L1) were found emerging from posterior to anterior between the costal margin and the iliac crest. Segmental nerves T10, T11, T12, and L1 were involved in the dye in 50%, 100%, 100%, and 93% of cases, respectively. CONCLUSIONS: This anatomical study shows that an ultrasound-guided TAP injection cephalad to the iliac crest is likely to involve the T10-L1 nerve roots, and implies that the technique may be limited to use in lower abdominal surgery.

Spread of injectate after ultrasound-guided subcostal transversus abdominis plane block: a cadaveric study.

Ultrasound-guided transversus abdominis plane (TAP) block can be performed using a subcostal technique. This technique was simulated using dye injection in cadavers in order to determine segmental nerve involvement and spread of injectate using either single or multiple-injection techniques. Dye most commonly spread to affect T9 and T10 nerves with the single injection technique and T9, T10 and T11 with multiple injections. The median (IQR [range]) spread of dye was 60 (36-63 [32-78]) cm(2) using the single-injection technique and 90 (85-96 [72-136]) cm(2), in the multiple-injection technique, and this difference was statistically significant (p = 0.003). These results indicate that ultrasound-guided subcostal TAP block will involve nerve roots T9, T10 and T11 and that a multiple-injection technique may block more segmental nerves and increase spread of injectate.

Report from the 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Saskatoon, Saskatchewan; 28-29 September 2018.

The 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference was held in Saskatoon, Saskatchewan, 28-29 September 2018. This interactive multidisciplinary conference is attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancers. In addition, invited speakers from other provinces participate. Surgical, medical, and radiation oncologists, and allied health care professionals participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancers.

Intravascular catheters-an ultrasound imaging based observational study of position and function.

Peripheral intravenous and intra-arterial catheters often block with movement of the limb in which they are inserted. Although the cause of this blockage is commonly attributed to a valve or other structure within the vein, evidence for this is lacking. We used ultrasound to assess the cause of blockage on movement, and degree of tip movement, of 62 venous and 21 radial arterial catheters. In both venous and arterial catheters, blockage was predominantly caused by impingement of the catheter on the vessel wall, with catheter kinking and spasm of the vessel also seen. Mean potential tip movement was 12.3 mm and 5.7 mm in hand and forearm venous catheters respectively and 9.5 mm in radial artery catheters. There was a significantly lower rate of blockage for forearm (20%) compared to dorsal hand venous catheters (83%, P <0.001) and 52% of radial artery catheters showed damping and blockage on wrist flexion. This study emphasises the advantages of placement of venous catheters in the straight veins of the forearm.

Comparison of extent of sensory block following posterior and subcostal approaches to ultrasound-guided transversus abdominis plane block.

Transversus abdominis plane block provides postoperative analgesia following abdominal surgery by targeting thoracolumbar nerves between the internal oblique and transversus abdominis muscles. Posterior and subcostal approaches using ultrasound guidance have been described. However there have been inconsistent results in relation to the extent of the sensory block. This observational study evaluated the distributions of sensory block following either a posterior or subcostal approach and the quality of analgesia achieved. Following ethics committee approval, 50 patients undergoing minimally invasive and major abdominal surgery were recruited. A total of 81 transversus abdominis plane blocks were performed preoperatively under real-time ultrasound guidance. Postoperatively, patients received multimodal analgesia including morphine via patient-controlled pumps. Ninety-eight percent of patients had some degree of demonstrable sensory block and the dermatomal spread differed between posterior and subcostal approaches (P < 0.001). The posterior approach produced a median sensory block of three dermatomal segments (interquartile range 2 to 4), the most cephalad being T10 (interquartile range T9 to T10), while the subcostal approach blocked a median of four segments (interquartile range 3 to 5), the most cephalad being T8 (interquartile range T7 to T9, P < 0.001). Maximum dermatomal block distribution was observed at 30 minutes and usually regressed by 24 hours. Median cumulative morphine consumption was 40.8 mg (interquartile range 17 to 50 mg) at 24 hours. Median pain scores at rest and with coughing were 20 (interquartile range 10 to 35) and 50 (interquartile range 29 to 67) respectively at 24 hours. The posterior approach appears to be more appropriate for lower abdominal surgery and the subcostal approach better suited to upper abdominal surgery. Whichever approach is used, transversus abdominis plane block is only one component of a multimodal analgesic technique.

Venous embolism of diathermy evolved gases complicating endometrial ablation using glycine irrigant.

A case is reported of venous gas embolism in a 44-year-old woman undergoing hysteroscopic endometrial ablation using glycine irrigation without gas insufflation. The postulated source of gases are the vapour and combustion products produced by the diathermy.

An application of immunocytology to the analysis of the cell kinetics of upper respiratory and digestive tract squamous carcinoma.

An antinucleoside immunofluorescence technique (ANIF) facilitated evaluation of labeling index (LI) from frozen sections of 36 upper respiratory and digestive tract squamous cancers (URDTS) from a group of 35 patients. There were 35 URDTS of the larynx, oral cavity, or pharynx and the LIs of this population ranged from 0-39.4%, (mean, 14.7%); 6% of URDTS (2 of 36) were not assessable by ANIF. The administration of nontherapeutic radioactive materials, the establishment of cell cultures, and perturbations in cell growth implicit in the removal of tumor from host prior to assessment are unnecessary in the application of this technique.