Emergencies in obstetric anaesthesia: a narrative review.

We conducted a narrative review in six areas of obstetric emergencies: category-1 caesarean section; difficult and failed airway; massive obstetric haemorrhage; hypertensive crisis; emergencies related to neuraxial anaesthesia; and maternal cardiac arrest. These areas represent significant research published within the last five years, with emphasis on large multicentre randomised trials, national or international practice guidelines and recommendations from major professional societies. Key topics discussed: prevention and management of failed neuraxial technique; role of high-flow nasal oxygenation and choice of neuromuscular drug in obstetric patients; prevention of accidental awareness during general anaesthesia; management of the difficult and failed obstetric airway; current perspectives on the use of tranexamic acid, fibrinogen concentrate and cell salvage; guidance on neuraxial placement in a thrombocytopenic obstetric patient; management of neuraxial drug errors, local anaesthetic systemic toxicity and unusually prolonged neuraxial block regression; and extracorporeal membrane oxygenation use in maternal cardiac arrest.

Determining the effective pre-oxygenation interval in obstetric patients using high-flow nasal oxygen and standard flow rate facemask: a biased-coin up-down sequential allocation trial.

Using biased-coin sequential allocation, we sought to determine the effective time interval in 90% of healthy parturients to achieve a target endpoint end-tidal oxygen of ≥ 90% using standard flow rate facemask and high-flow nasal oxygen. Eighty healthy parturients were randomly assigned to standard facemask (n = 40) or high-flow nasal oxygen (n = 40) groups; half of the parturients in the high-flow nasal oxygen group also used a simple no-flow facemask to minimise air entrainment. The effective time interval for 90% of parturients to achieve the target endpoint for standard facemask was 3.6 min (95%CI 3.3-6.7 min), but could not be estimated for the high-flow nasal oxygen groups with or without an additional simple facemask, as eight minutes was insufficient to achieve the target endpoint for 55% and 92% of parturients, respectively. Furthermore, after three minutes, the target endpoint was reached by 71% in the standard facemask group vs. 0% in the high-flow nasal oxygen groups. After four minutes, the target endpoint was reached by 100% in the standard facemask, 80% in the high-flow nasal oxygen with simple facemask and 67% in the high-flow nasal oxygen groups. Beyond four minutes, there was no improvement in pre-oxygenation success using high-flow nasal oxygen. In conclusion, under the conditions of our study, the effective time interval for 90% of parturients to achieve an end-tidal oxygen ≥ 90% for standard flow rate facemask was estimated to be 3.6 min, but could not be estimated for high-flow nasal oxygen groups even after eight minutes.

High-flow nasal oxygen vs. standard flow-rate facemask pre-oxygenation in pregnant patients: a randomised physiological study.

High-flow nasal oxygen has been shown to provide effective pre-oxygenation and prolong apnoeic time during intubation attempts in non-pregnant patients. We aimed to compare pre-oxygenation using high-flow nasal oxygen (30-70 l.min-1 oxygen flow) via nasal prongs with standard 15 l.min-1 oxygen breathing via a tight-fitting facemask. Forty healthy parturients were randomly allocated to these two groups, and furthermore each patient underwent the selected pre-oxygenation method with both 3-min tidal volume breathing and 30s tidal breathing followed by eight vital capacity breaths. With 3-min tidal volume breathing, the respective estimated marginal means for high-flow nasal oxygen and standard flow rate facemask pre-oxygenation were 87.4% (95%CI 85.5-89.2%) and 91.0% (95%CI 89.3-92.7%), p = 0.02; with eight vital capacity breaths the estimated marginal means were 85.9% (95%CI 84.1-87.7%) and 91.8% (95%CI 90.1-93.4%, p < 0.0001). Furthermore, high-flow nasal oxygen did not reliably achieve a mean end-tidal oxygen concentration ≥ 90% compared with the standard flow rate facemask. In this physiological study, high-flow nasal oxygen pre-oxygenation performed worse than standard flow rate facemask pre-oxygenation in healthy term parturients.

Analysing breast tissue composition with MRI using currently available short, simple sequences.

AIM: To determine the most robust commonly available magnetic resonance imaging (MRI) sequence to quantify breast tissue composition at 1.5 T. MATERIALS AND METHODS: Two-dimensional (2D) T1-weighted, Dixon fat, Dixon water and SPAIR images were obtained from five participants and a breast phantom using a 1.5 T Siemens Aera MRI system. Manual segmentation of the breasts was performed, and an in-house computer program was used to generate signal intensity histograms. Relative trough depth and relative peak separation were used to determine the robustness of the images for quantifying the two breast tissues. Total breast volumes and percentage breast densities calculated using the four sequences were compared. RESULTS: Dixon fat histograms had consistently low relative trough depth and relative peak separation compared to those obtained using other sequences. There was no significant difference in total breast volumes and percentage breast densities of the participants or breast phantom using Dixon fat and 2D T1-weighted histograms. Dixon water and SPAIR histograms were not suitable for quantifying breast tissue composition. CONCLUSION: Dixon fat images are the most robust for the quantification of breast tissue composition using a signal intensity histogram.

Colonic prolapse after intersphincteric resection for very low rectal cancer: a report of 12 cases.

BACKGROUND: There are no published data concerning management of patients with exteriorized colonic prolapse (CP) after intersphincteric rectal resection (ISR) and side-to-end coloanal manual anastomosis (CAA) for very low rectal cancer. The aim of the present study was to report our experience in 12 consecutive cases of CP following ISR with CAA. METHODS: From 2006 to 2014, all patients with very low rectal cancer who developed CP after ISR and CAA were reviewed. Demographic and surgical data, prolapse symptoms and treatment were recorded. Postoperative morbidity, functional outcomes and results after prolapse surgery were recorded. RESULTS: Twelve out of 143 patients (8 %) who underwent ISR with side-to-end CAA for low rectal cancer presented CP: 7/107 ISR (7 %) with partial resection of the internal anal sphincter (IAS) and 5/36 ISR (14 %) with subtotal or total resection of the IAS (NS). CP was diagnosed after a median of 6 months (range 2-72 months) after ISR. All patients with CP suffered from pain and fecal incontinence. Median Wexner fecal incontinence score before surgery was 16.5 (range 12-20). Three patients refused reoperation. Nine patients underwent transanal surgery with prolapse resection (including colonic stump and side-to-end anastomosis) and new end-to-end CAA (with posterior myorraphy in 4 cases). After a median follow-up of 30 months (range 8-87 months), 3/9 patients (33 %) had CP recurrence: One with very poor function was treated by abdominoperineal resection and definitive stoma. The 2 others were successfully reoperated on transanally. Median Wexner fecal incontinence score after CP surgery was 9 (range 0-20). No CP recurrence was noted for the 6 other patients, and function improved in all cases. Thus, at the end of follow-up, 8/9 patients (89 %) had no recurrence after surgery. CONCLUSIONS: We believe surgery must be attempted in these patients who develop CP after ISR with CAA for very low rectal cancer in order to improve function and symptoms. A transanal approach with CP resection and new end-to-end anastomosis appeared to be safe and effective. Larger studies are needed to confirm our results.

What happens after R1 resection in patients undergoing laparoscopic total mesorectal excision for rectal cancer? A study in 333 consecutive patients.

AIM: There are no studies on the respective influence of microscopic involvement at the circumferential (R1c) and the distal margin (R1d) of the surgical specimen on oncological results after laparoscopic mesorectal excision. METHOD: We studied 333 consecutive patients undergoing laparoscopic mesorectal excision for cancer. An R1 resection was defined a by a circumferential and/or distal margin of 1 mm or less. RESULTS: Forty (12%) patients had an R1 resection including R1c [n = 28 (70%)], R1d [n = 7 (18%)] or both [n = 5 (12%)]. After a mean of 28 (0-97) months, comparisons of R1 with R0 resection were as follows: mortality 10% and 4% (NS), overall recurrence 48% and 19% (P < 0.001), 2-year disease-free survival rate 51% and 76% (P < 0.001) and overall survival (OS) rate 91% and 96% (NS). For R1c patients mortality was 14% (4% for R0; P = 0.026), overall recurrence 46% (19% for R0; P = 0.028) and 2-year OS 88% (96% for R0; P = 0.025). No significant differences were found between R1d and R0. The metastatic recurrence rate was greater in R1c then R0 (29% vs 12%; P = 0.036) but not for R1d (14% vs 12%; NS). Locoregional recurrence rates of R1c (7%) and R1d (0%) were similar to R0 (4%). CONCLUSION: This study shows that the poorer prognosis observed after R1 resection for rectal cancer is due to circumferential rather than distal involvement. This is mainly related to a higher rate of metastatic recurrence.

Simultaneous real-time imaging of four-chamber and left ventricular outflow tract views using xPlane imaging capability of a matrix array probe.

OBJECTIVES: To determine the feasibility and reliability of using xPlane imaging to examine simultaneously the four-chamber and left ventricular outflow tract (LVOT) views in real time, to assess rotation angles from the four-chamber view to the LVOT view, and to investigate factors affecting the angles. METHODS: In 145 fetuses at 11-37 weeks' gestation, we visualized the four-chamber view in one of three cardiac positions: a subcostal view with the apex at the 3 or 9 o'clock position; an apical view with the apex at the 12 or 6 o'clock position; or a view with the fetal heart apex midway between these two positions. We then used the rotation function of xPlane imaging, using the four-chamber view as the reference plane, to visualize the LVOT view simultaneously in real time on the secondary image plane, on the right side of the split screen, by rotating a reference line from 0° with a rotation step of 5°. The rotation angle necessary for the first appearance of LVOT was recorded as the first rotation angle. The reference line was then rotated until the LVOT was just out of view, and this last rotation angle was recorded as the second rotation angle. The difference between these two angles was recorded as the angle span of the LVOT display. Reliability was assessed by intraclass correlation coefficient (ICC). RESULTS: Of the 145 fetuses examined, 29 had cardiac defects. Using xPlane imaging, the LVOT was visualized successfully after 14 weeks in 95.1% of cases. The first and second rotation angles varied significantly with cardiac position (P < 0.001); when the fetal heart was examined using a subcostal approach with the apex at the 3 or 9 o'clock position, the first rotation angle was smaller than that at the apical view for normal hearts (20° vs. 50°, P < 0.001). There was also a significant difference for the second rotation angle and for the angle span, between fetuses with and without normal LVOT (P = 0.038 and 0.006, respectively). Regarding intra- and interobserver reliability for measurement of first and second rotation angles, the ICCs were high (range, 0.847-0.980). CONCLUSION: Using xPlane imaging, it is feasible to examine simultaneously the four-chamber and LVOT views in real time, and measurement of the rotation angles between these two views is reproducible. The rotation angles depend on the position of the fetal heart, and the normality of the LVOT. Proposed algorithms for examination of the fetal heart with three-/four-dimensional ultrasonography may need to be adapted to optimize visualization of the standard planes.

The incidence of dry chlorhexidine gluconate transfer from skin to surgical gloves: a simulation and in vitro study.

BACKGROUND: To prevent alcohol-based chlorhexidine from reaching the cerebrospinal fluid, it is recommended that the antiseptic solution be allowed to dry before skin palpation or puncture. However, no guidelines specify a drying time interval. Manufacturers recommend 3 min of air drying, based upon the isopropyl alcohol component. Therefore, to fill this knowledge gap, we designed a simulation study to investigate the incidence of primary chlorhexidine transfer from skin to gloves following three drying time intervals. We also investigated the incidence of secondary chlorhexidine transfer from gloves to another surface following one drying time interval. METHODS: An alcohol-based chlorhexidine antiseptic solution with dye, ChloraPrep®, was applied to the skin of the lumbar region of 20 volunteers. Cotton-tipped applicators wrapped in material from gloves were taken from the application area at 3, 4, 5, and 10 min following application. Transfer of chlorhexidine from skin to gloves, and gloves to another medium, was assessed through a chemical assay that produced a color change when chlorhexidine was present on the sample. RESULTS: The incidence of primary chlorhexidine transfer from skin to gloves at 3, 4 and 10 min following application was 99.5%, 99.4%, and 99.6%, respectively. The incidence of secondary chlorhexidine transfer from gloves to another surface was 68.9%. CONCLUSION: Gloves are routinely contaminated with chlorhexidine during central neuraxial blockade. The high incidence of secondary transfer in our simulation suggests a pathway by which chlorhexidine may gain access to the neuraxial space.

Impact of adherence goal awareness intervention on PDC in various settings: Does awareness help modify medication-taking behavior?

Background: Interventions to improve medication adherence in chronic conditions have shown limited success or sustainability. Previous data revealed that phone calls to patients regarding adherence goal awareness resulted in significant improvement in proportion of days covered (PDC). Objectives: The objective of this study was to explore specific pharmacist adherence interventions via phone in various practice settings. Methods: A prospective, randomized controlled study was conducted with patients who belonged to university-associated health care settings [ambulatory care, chain store, small health plan, and federally qualified health center (FQHC)]. At each site, patients with at least one chronic medication and a calculated PDC < 0.80 were randomized into control (n=115) and intervention (n=126) groups. Control groups (C) received usual pharmacy communication while intervention groups (X) were specifically called by a pharmacist to be informed of PDC goals and their commitment to adherence. PDC values were calculated 3 to 12 months for both groups the time of intervention, then compared with each patient's respective baseline/pre-PDC. Results: Data from a total of 241 patients were pooled to examine change in PDC. There was no significant difference between groups in baseline criteria or PDC. Comparing within groups, there were significant correlations between Pre- and Post-PDCs for the intervention group (X = 0.32 p < 0.05) alone. There were significant improvements from initial PDC to those calculated at the time of Post-intervention PDC within both groups, (C = 0.18 ± 0.28 p < 0.05) and (X = 0.16 ± 0.24, p < 0.05). Approximately 44% of all sampled patients reached their adherence goals (PDC ≥ 0.80) after 3-9 months. Conclusions: Results suggested that patient adherence behavior may improve after any call made by pharmacy staff. This communication and attention from the pharmacy may be enough for patients to consider their medication-taking habits without the need for discussing specific goals and importance of adherence.

Fructose Metabolism and Cardiac Metabolic Stress.

Cardiovascular disease is one of the leading causes of mortality in diabetes. High fructose consumption has been linked with the development of diabetes and cardiovascular disease. Serum and cardiac tissue fructose levels are elevated in diabetic patients, and cardiac production of fructose via the intracellular polyol pathway is upregulated. The question of whether direct myocardial fructose exposure and upregulated fructose metabolism have potential to induce cardiac fructose toxicity in metabolic stress settings arises. Unlike tightly-regulated glucose metabolism, fructose bypasses the rate-limiting glycolytic enzyme, phosphofructokinase, and proceeds through glycolysis in an unregulated manner. In vivo rodent studies have shown that high dietary fructose induces cardiac metabolic stress and functional disturbance. In vitro, studies have demonstrated that cardiomyocytes cultured in high fructose exhibit lipid accumulation, inflammation, hypertrophy and low viability. Intracellular fructose mediates post-translational modification of proteins, and this activity provides an important mechanistic pathway for fructose-related cardiomyocyte signaling and functional effect. Additionally, fructose has been shown to provide a fuel source for the stressed myocardium. Elucidating the mechanisms of fructose toxicity in the heart may have important implications for understanding cardiac pathology in metabolic stress settings.

A review of the Turned-down Onto Pericapsular-tissue Hemisectioned Amputated Toe (TOPHAT) flap for wound coverage during ray amputations of the toes.

INTRODUCTION: Exposure of the adjacent Metatarsal-Phalangeal Joint (MTPJ) commonly occurs after application of Topical Negative Pressure Wound Therapy (TNPWT) for a ray amputation wound. This is due to mechanical soft tissue erosion or trauma to the adjacent digital artery from direct pressure effect. This results in toe gangrene requiring a ray amputation and ultimately a larger wound bed. We describe the use of the Turned-down Onto Pericapsular-tissue Hemisectioned Amputated Toe (TOPHAT) flap - a filleted toe flap to protect the adjacent MTPJ capsule combined with a novel Negative Pressure Wound Therapy with instillation and dwell-time (NPWTi-d) dressing technique. The flap protects the adjacent joint capsule and reduces the wound burden whilst allowing the wound to benefit from TNPWT, thereby accelerating wound healing. MATERIAL AND METHODS: A retrospective review was conducted of patients with toe gangrene requiring ray amputation that underwent the TOPHAT flap on in our institution from 2019 and 2020. Complications such as wound dehiscence, hematoma, flap necrosis and secondary infection were recorded. Other outcomes recorded were time taken to final skin grafting and time taken for complete wound epithelialization. RESULTS: 9 patients underwent treatment with the TOPHAT flap. 2 patients had flap necrosis. 7 patients progressed to definitive skin coverage with skin grafting. One patient subsequently had progressive arterial disease despite successful skin grafting and required above knee amputation. The mean time to final skin grafting and complete wound epithelialization was 49.5 days and 107.5 days respectively. All patients were satisfied with the outcomes and were able to return to their pre-morbid function. CONCLUSIONS: The TOPHAT flap has a consistent vascular supply that provides durable soft tissue coverage. It is a robust and easily reproducible technique to accelerate wound healing after ray amputations even in patients with peripheral vascular disease.

Peripartum management of a parturient with type 1C (clearance) von Willebrand disease.

Peripartum replacement of factor VIII and von Willebrand factor is not usually required in type 1 von Willebrand disease, as the levels of endogenous factors tend to increase to within the normal range as a physiological change of pregnancy. However, there is wide heterogeneity of genotypes and phenotypes associated with type 1 von Willebrand disease. Here, we describe the anesthetic management of a parturient with type 1C von Willebrand disease, a subtype characterized by decreased plasma von Willebrand factor survival.

Clinical impact of a pharmacist-physician co-managed programme on hyperlipidaemia management in Hong Kong.

OBJECTIVE: The study aimed to investigate the clinical impact of pharmacist-physician co-managed programme on the management of hyperlipidaemia. METHODS: The study was a prospective randomized controlled trial. Adult patients were selected if: (i) they were taking one or more lipid-lowering agents with a valid lipid panel before their next follow up; (ii) had a baseline lipid profile within the previous 6 months; (iii) their lipid panel did not reach the targeted low-density lipoprotein-cholesterol (LDL-C) goal based on the National Cholesterol Education Programme Adult Treatment Panel III. Pharmacists interviewed patients in the intervention group for 15-30 min to provide consultation on the drug regimen and lifestyle modifications. A telephone follow-up every 4 weeks and a follow-up interview on the date of the physician visit were scheduled. Patients in the control group received routine conventional care. The primary outcome measurement was the change in lipid panel between baseline and at the end of study. RESULTS: One hundred and eighteen patients were recruited to the study [58 patients in intervention group (mean age 63 +/- 10 years old) and 60 in control group (mean age 61 +/- 12 years old)]. Starting with similar baseline levels, the end of study LDL-C and total cholesterol levels for the intervention and control groups were LDL-C: 2.80 +/- 0.89 mmol/L and total cholesterol 4.75 +/- 1.08 mmol/L vs. LDL-C: 3.24 +/- 0.78 mmol/L and total cholesterol 5.18 +/- 0.93 mmol/L, respectively. The differences were statistically significant (P < 0.0015). CONCLUSION: The study showed that a pharmacist-physician co-managed programme for hyperlipidaemic patient was effective in getting more patients to reach their target lipid levels.