Gastric Point of Care Ultrasound in Adults: Image Acquisition and Interpretation

Over the past two decades, diagnostic point-of-care ultrasound (POCUS) has emerged as a rapid and non-invasive bedside tool for addressing clinical inquiries related to gastric content. One emerging concern pertains to patients about to undergo sedation and/or endotracheal intubation: the elevated risk of aspiration from the patient's stomach contents. Aspiration of gastric contents into the lungs poses a serious and potentially life-threatening complication. This occurs more frequently when the stomach is considered "full" and can be affected by the techniques employed for airway management, making it potentially preventable. To mitigate the risk of peri-procedural aspiration, two distinct medical specialties (anesthesiology and critical care medicine) have independently developed techniques to utilize ultrasonography for identifying patients requiring "full stomach" precautions. Due to these separate specialties, the work of each group remains relatively unfamiliar outside its respective field. This article presents descriptions of both techniques for gastric ultrasound. Furthermore, it explains how these approaches can complement each other when one of them falls short. Regarding image acquisition, the article covers the following topics: indications and contraindications, selection of the appropriate probe, patient positioning, and troubleshooting. The article also delves into image interpretation, complete with example images. Additionally, it demonstrates how one of the two techniques can be employed to estimate gastric fluid volume. Lastly, the article briefly discusses medical decision-making based on the findings of this examination.

Effectiveness of oral versus intravenous tranexamic acid in primary total hip and knee arthroplasty: a randomised, non-inferiority trial

BACKGROUND

Tranexamic acid (TXA) reduces rates of blood transfusion for total hip arthroplasty (THA) and total knee arthroplasty (TKA). Although the use of oral TXA rather than intravenous (i.v.) TXA might improve safety and reduce cost, it is not clear whether oral administration is as effective.

METHODS

This noninferiority trial randomly assigned consecutive patients undergoing primary THA or TKA under neuraxial anaesthesia to either one preoperative dose of oral TXA or one preoperative dose of i.v. TXA. The primary outcome was calculated blood loss on postoperative day 1. Secondary outcomes were transfusions and complications within 30 days of surgery.

RESULTS

Four hundred participants were randomised (200 THA and 200 TKA). The final analysis included 196 THA patients (98 oral, 98 i.v.) and 191 TKA patients (93 oral, 98 i.v.). Oral TXA was non-inferior to i.v. TXA in terms of calculated blood loss for both THA (effect size=-18.2 ml; 95% confidence interval [CI], -113 to 76.3; P<0.001) and TKA (effect size=-79.7 ml; 95% CI, -178.9 to 19.6; P<0.001). One patient in the i.v. TXA group received a postoperative transfusion. Complication rates were similar between the two groups (5/191 [2.6%] oral vs 5/196 [2.6%] i.v.; P=1.00).

CONCLUSIONS

Oral TXA can be administered in the preoperative setting before THA or TKA and performs similarly to i.v. TXA with respect to blood loss and transfusion rates. Switching from i.v. to oral TXA in this setting has the potential to improve patient safety and decrease costs.

Core outcome set for peripheral regional anesthesia research: a systematic review and Delphi study

BACKGROUND/IMPORTANCE

There is heterogeneity among the outcomes used in regional anesthesia research.

OBJECTIVE

We aimed to produce a core outcome set for regional anesthesia research.

METHODS

We conducted a systematic review and Delphi study to develop this core outcome set. A systematic review of the literature from January 2015 to December 2019 was undertaken to generate a long list of potential outcomes to be included in the core outcome set. For each outcome found, the parameters such as the measurement scale, timing and definitions, were compiled. Regional anesthesia experts were then recruited to participate in a three-round electronic modified Delphi process with incremental thresholds to generate a core outcome set. Once the core outcomes were decided, a final Delphi survey and video conference vote was used to reach a consensus on the outcome parameters.

RESULTS

Two hundred and six papers were generated following the systematic review, producing a long list of 224 unique outcomes. Twenty-one international regional anesthesia experts participated in the study. Ten core outcomes were selected after three Delphi survey rounds with 13 outcome parameters reaching consensus after a final Delphi survey and video conference.

CONCLUSIONS

We present the first core outcome set for regional anesthesia derived by international expert consensus. These are proposed not to limit the outcomes examined in future studies, but rather to serve as a minimum core set. If adopted, this may increase the relevance of outcomes being studied, reduce selective reporting bias and increase the availability and suitability of data for meta-analysis in this area.

Posttransplantation lymphoproliferative disorders in bone marrow transplant recipients are aggressive diseases with a high incidence of adverse histologic and immunobiologic features

Posttransplantation lymphoproliferative disorders (PT-LPDs) occurring in T-cell depleted (TCD) allogeneic bone marrow transplant recipients seem to be different from those that arise in solid organ recipients in their early development, the high incidence of extensive dissemination at presentation, and their aggressive course and high fatality rate. We report a series of 10 patients with PT-LPDs after TCD allogeneic bone marrow transplant. We studied the correlation between the morphology of the lesions; their clonality based on immunoglobulin (Ig) heavy chain gene rearrangement analysis and immunohistochemistry; their proliferative activity as measured by immunoperoxidase staining for the proliferating cell nuclear antigen (PCNA) and the presence of p53 gene product overexpression. Histologically, our cases corresponded to the two morphologic categories of polymorphic B-cell lymphoma (PBCL, seven cases) and malignant lymphoma immunoblastic (ML-IB, three cases). Ig light-chain staining showed monoclonality in a minority of the cases, whereas Ig gene rearrangement analysis by polymerase chain reaction revealed B-cell clonality in three of seven cases of PBCL and in all three cases of ML-IB. The Epstein-Barr virus (EBV) genome, the expression of EBV latent membrane protein or both were found in all 10 specimens. High proliferative activity (PCNA > or = 66%) was found in all cases, with a mean PCNA value of 56% in PBCL and 84% in ML-IB. Five specimens were p53+ (two of seven PBCL and three of three ML-IB). Two of four PBCL cases resolved with the administration of donor leukocytes. All of the remaining patients died of the PT-LPD within a short time from admission. Our results show that the PT-LPDs after TCD bone marrow transplantation are characterized by a high frequency of high-grade histologic subtypes, frequent monoclonality, high proliferative activity, frequent overexpression of p53 gene product, and poor prognosis. These characteristics observed in only a minority of cases of PT-LPDs occurring after solid organ transplantation may account for the less aggressive clinical behavior observed in those diseases.

Hypoplastic myelodysplastic syndromes can be distinguished from acquired aplastic anemia by CD34 and PCNA immunostaining of bone marrow biopsy specimens

Hypoplastic myelodysplastic syndromes (h-MDSs) are difficult to distinguish from acquired aplastic anemia (AA) because of the considerable clinical, cytologic, and histologic similarities between these two disorders. Recent studies have suggested that the bone marrow (BM) in AA is characterized by a decreased number of CD34+ cells and reduced expression of proliferating cell nuclear antigen (PCNA), features that have not been associated with MDS. To determine the potential importance of these markers in the differential diagnosis of hypoplastic BM disorders, we immunostained 50 BM biopsy specimens of cytogenetically characterized cases of AA (27) and h-MDS (23). Immunohistochemical staining for CD34 was performed with QBEND10 (Vector, Burlingame, Calif), a monoclonal antibody (MoAb) reactive in routinely processed specimens, while PCNA was assessed by the PC10 MoAb (Dako, Carpinteria, Calif) using a microwave over-based antigen retrieval technique. Bone marrow specimens of h-MDS cases showed statistically higher values of PCNA and CD34 than did those of the AA cases: mean values (+/- SD) of CD34-positive cells in h-MDS, 0.94% +/- 1.1; AA, 0.04% +/- 0.1 (P = .0002); PCNA-positive cells in h-MDS, 43.59% +/- 13.3; AA, 14.80% +/- 6.4 (P < .0001). Our study confirms that AA is characterized by low expression of PCNA in BM and reduced CD34 frequency compared with h-MDS and supports the concept of an early deficiency of stem cells in the former disorder. The results also illustrate how immunostaining permits a simple distinction of these conditions in routinely processed BM biopsy specimens.

A lyophilized hemoglobin control prepared from stroma-free hemolysates

We prepared a stable lyophilized hemoglobin control from human erythrocytes by removing stroma with calcium and Ficoll. Addition of polyhydroxy compounds enhanced reconstitution and stability. The lyophilized product was stable during one year of use in a service laboratory. Accelerated aging studies demonstrated the potential of up to two years of stability, with methemoglobin increasing at a projected rate of approximately 6% per year. Reconstituted, the control gave reproducible values for at least five days when refrigerated.

A lyophilized hemoglobin control prepared from stroma-free hemolysates

We prepared a stable lyophilized hemoglobin control from human erythrocytes by removing stroma with calcium and Ficoll. Addition of polyhydroxy compounds enhanced reconstitution and stability. The lyophilized product was stable during one year of use in a service laboratory. Accelerated aging studies demonstrated the potential of up to two years of stability, with methemoglobin increasing at a projected rate of approximately 6% per year. Reconstituted, the control gave reproducible values for at least five days when refrigerated.

A lyophilized hemoglobin control prepared from stroma-free hemolysates

We prepared a stable lyophilized hemoglobin control from human erythrocytes by removing stroma with calcium and Ficoll. Addition of polyhydroxy compounds enhanced reconstitution and stability. The lyophilized product was stable during one year of use in a service laboratory. Accelerated aging studies demonstrated the potential of up to two years of stability, with methemoglobin increasing at a projected rate of approximately 6% per year. Reconstituted, the control gave reproducible values for at least five days when refrigerated.