Breathing with fins: do the pectoral fins of larval fishes play a respiratory role?

Convective water flow across respiratory epithelia in water-breathing organisms maintains transcutaneous oxygen (O2) partial pressure (Po2) gradients that drive O2 uptake. Following hatch, larval fishes lack a developed gill and the skin is the dominant site of gas transfer, yet few studies have addressed the contribution of convective water flow to cutaneous O2 uptake in larvae. We hypothesized that the pectoral fins, which can generate water flow across the skin in larvae, promote transcutaneous O2 transfer and thus aid in O2 uptake. In zebrafish (Danio rerio), the frequency of pectoral fin movements increased in response to hypoxia at 4 days postfertilization (dpf), but the response was blunted by 15 dpf, when the gills become the dominant site of O2 uptake, and was absent by 21 dpf. In rainbow trout (Oncorhynchus mykiss), Po2 measured at the skin surface of ventilating larvae was lower when the pectoral fins had been surgically removed, directly demonstrating that fins contribute to convective flow that dissipates cutaneous Po2 boundary layers. Lack of pectoral fins compromised whole animal O2 consumption in trout during hypoxia, but this effect was absent in zebrafish. Overall, our findings support a respiratory role of the pectoral fins in rainbow trout, but their involvement in zebrafish remains equivocal.

Red blood cell transfusion in adult palliative care: a systematic review.

BACKGROUND: The risks and benefits of red blood cell (RBC) transfusion in palliative care patients remain poorly understood. We reviewed the literature to summarize available information on RBC transfusion in this population. STUDY DESIGN AND METHODS: We searched electronic databases (MEDLINE, Embase, PsycINFO, CINAHL) from inception through September 2016 to identify studies reporting data on palliative patients receiving RBC transfusion. Original studies that assessed RBC transfusion as an intervention and reported at least one clinical outcome were included. Study characteristics, results on transfusion-related outcomes, and authors' conclusions on the value of transfusion in palliative patients were abstracted and reported. RESULTS: We identified 1839 studies, of which 137 were selected for data extraction and 13 were included (11 case series, one prospective cohort, and one retrospective cohort). Nine studies addressed symptom relief following transfusion using subjective symptom scales, of which eight (89%) indicated some degree of short-term benefit and one study (11%) showed no benefit. Posttransfusion survival was reported in four studies-one demonstrated prolonged survival in patients receiving RBC transfusion; three had no comparison group. Other outcomes reported included hemoglobin values posttransfusion in four studies and adverse events following transfusion in three studies. CONCLUSIONS: In palliative care, RBC transfusion may provide symptom relief and improve subjective well-being, though the duration and magnitude of this effect, and transfusion-associated risks specific to this population remain unclear. Currently, no high quality evidence exists to support or guide the use of RBC transfusion in this population. Moreover, the clinical heterogeneity within the palliative population limits the interpretation of most studies.

Perioperative protocols in ambulatory breast reconstruction: A systematic review.

INTRODUCTION: Recent studies have successfully employed perioperative protocols and Enhanced Recovery After Surgery (ERAS) protocols to promote and increase the range of breast reconstruction procedures performed in ambulatory settings. This systematic review aims to identify the common perioperative protocol items associated with successful ambulatory breast reconstruction. METHODS: A systematic review of electronic databases (Ovid Medline, EMBASE, and Cochrane) was conducted. Studies that described the perioperative care protocol for postmastectomy breast reconstruction in ambulatory settings (discharge within 24 h) were included. Two reviewers independently screened the literature and extracted the data. Risk of bias was assessed with the National Heart, Lung, and Blood Institute quality tool. The perioperative protocol details, type of reconstruction, information regarding patient selection criteria, successful discharge rates, and complication rates were extracted. RESULTS: Twelve studies were included in the systematic review, with 1484 patients undergoing ambulatory breast reconstruction with a well-defined perioperative protocol. Sixteen perioperative items were identified. The most discussed items were preoperative counseling (11/12), preoperative and intraoperative multimodal analgesia (11/12), and postoperative analgesia (10/12). Our recommendation includes two new items and seven modified items compared to previous ERAS guidelines. Overall, the mean number of items was 9.22 in same-day discharge and 6.75 in 24-h discharge (P = 0.169). 78.4% of the patients (1123 of 1433) were successfully discharged within 24 h. No studies identified an increase in readmission or complications with ambulatory discharge. CONCLUSION: Sixteen core items were defined for a successful perioperative ERAS protocol for 24-h discharge breast reconstruction. Implementing perioperative protocols can facilitate under-24-h discharge for alloplastic and autologous surgery.