Optimizing Tourniquet Pressure in Upper Extremity Surgery.

Background: Pneumatic tourniquet is an effective tool to achieve hemostatic control of the surgical field in upper extremity (UE) operations. Elevated pressures have been associated with adverse effects despite various methods of pressure determination. We aim to demonstrate the usage of reduced tourniquet pressures and examine factors associated with achieving reduced pressures. Methods: A prospective study was conducted (2016-2018) at a Level 1 Trauma Center and an Outpatient Surgical Center, totaling 226 operations, involving a reduction of cuff pressures over time from a standard baseline of limb occlusion pressure for UE operations. Results: A gradual reduction of pressures was successfully achieved with a mean pressure of 187 mmHg and average time of tourniquet application being 25 minutes. We found chronological surgical number and patient BMI to be significantly associated with tourniquet pressure (p < 0.05). 4.5% of cases resulted in breakthrough bleeding, but did not reliably occur with any pressure thresholds, patient demographics, or operative factors (p > 0.05, for all). Conclusions: Reduced tourniquet pressures can mitigate complications associated with tourniquet use. Our research shows reduced pressures are successful in maintaining field visibility and we encourage an adoption of pressures below 200 mm Hg in most procedures that require a tourniquet.

Insight into the sulfur metabolism of Desulfurella amilsii by differential proteomics.

Many questions regarding proteins involved in microbial sulfur metabolism remain unsolved. For sulfur respiration at low pH, the terminal electron acceptor is still unclear. Desulfurella amilsii is a sulfur-reducing bacterium that respires elemental sulfur (S0 ) or thiosulfate, and grows by S0 disproportionation. Due to its versatility, comparative studies on D. amilsii may shed light on microbial sulfur metabolism. Requirement of physical contact between cells and S0 was analyzed. Sulfide production decreased by around 50% when S0 was trapped in dialysis membranes, suggesting that contact between cells and S0 is beneficial, but not strictly needed. Proteome analysis was performed under the aforementioned conditions. A Mo-oxidoreductase suggested from genome analysis to act as sulfur reductase was not detected in any growth condition. Thiosulfate and sulfite reductases showed increased abundance in thiosulfate-reducing cultures, while rhodanese-like sulfurtransferases were highly abundant in all conditions. DsrE and DsrL were abundantly detected during thiosulfate reduction, suggesting a modified mechanism of sulfite reduction. Proteogenomics suggest a different disproportionation pathway from what has been reported. This work points to an important role of rhodaneses in sulfur processes and these proteins should be considered in searches for sulfur metabolism in broader fields like meta-omics.

Autologous breast reconstruction with the inchworm flap in an obese woman.

Breast cancer may particularly occur in the obese female population. Although mastectomy can be a life-saving procedure, it frequently leaves soft tissue defects and deformities that can be psychologically and esthetically upsetting to the patient. A number of reconstructive methods have been utilized including prosthetic implants, TRAM flaps, and latissimus dorsi myocutaneous flaps. We present an obese woman who underwent a novel method of post-mastectomy breast reconstruction using a staged lateral chest wall fasciocutaneous advancement flap which we term the 'inchworm flap'. The patient had good outcome with no complications. In a select group of obese patients who have redundant lateral chest wall soft tissue following mastectomy, this technique can be a successful means of recreating the breast mound using autologous tissue.

Fulminant infection and toxic shock syndrome caused by Streptococcus pyogenes.

Two patients presented to the Emergency Department (ED) with features of toxic shock syndrome, including hypotension, acute respiratory distress syndrome (ARDS), renal and hepatic insufficiency and disseminated intravascular coagulation (DIC). Computed tomography (CT) scan identified the source of infection in one patient. At laparotomy, pelvic peritonitis and massive edema of the pelvic retroperitoneal tissue was found. The other patient had myonecrosis of the forearm necessitating amputation. Intra-operative cultures of tissue in each case yielded Streptococcus pyogenes, Group A. These patients were treated early with clindamycin and intensive supportive care as well as surgery, and both made a full recovery. Because of the necessity of early recognition of the varied presentation of these infections, the clinical features as well as essential interventions are emphasized. We review the pathophysiology of invasive Group A streptococcal infection to increase awareness of these uncommon but fulminant and often lethal infections.