The chasmogamous/cleistogamous (CH/CL) breeding system has evolved independently many times, but its ecological role has been studied in few species. In Triodanis perfoliata, we studied the natural ...phenology of flowering and seed set, how successful CH flowers were at setting seed, whether seed from CH and CL flowers differed in germination behavior, and whether plants derived from these two seed types differed in vigor. Most notably, we found that the later the CH flowers were produced, the fewer seed they successfully matured. In general the two seed types did not show differences in germination behavior, but for some maternal parents the two seed types differed. For these, the CL seed germinated less readily. Finally, there was some indication that plants from CL seed were not as vigorous as those from CH seed.
Raunkiaer's life-form designations were used to produce several spectra for the flora of a recently exposed mudflat located on the Scioto River, Delaware County, Ohio. These spectra contain a high ...percentage of hemicryptophytes, which confirms previous life-form studies of eastern North American floras. However, the high percentage of therophytes (annual plants) in the spectra of a mudflat flora has not previously been reported for this phytoclimatic region, and suggests that localized factors such as disturbance may play a significant role in the determination of life-forms in specific habitats. Altering Raunkiaer's method to include species abundance values had little impact on the resulting spectra calculated for the mudflat flora.
Postoperative delirium is common following cardiac surgery and may be affected by choice of analgesic and sedative.
To evaluate the effect of postoperative intravenous (IV) acetaminophen ...(paracetamol) vs placebo combined with IV propofol vs dexmedetomidine on postoperative delirium among older patients undergoing cardiac surgery.
Randomized, placebo-controlled, factorial clinical trial among 120 patients aged 60 years or older undergoing on-pump coronary artery bypass graft (CABG) surgery or combined CABG/valve surgeries at a US center. Enrollment was September 2015 to April 2018, with follow-up ending in April 2019.
Patients were randomized to 1 of 4 groups receiving postoperative analgesia with IV acetaminophen or placebo every 6 hours for 48 hours and postoperative sedation with dexmedetomidine or propofol starting at chest closure and continued for up to 6 hours (acetaminophen and dexmedetomidine: n = 29; placebo and dexmedetomidine: n = 30; acetaminophen and propofol: n = 31; placebo and propofol: n = 30).
The primary outcome was incidence of postoperative in-hospital delirium by the Confusion Assessment Method. Secondary outcomes included delirium duration, cognitive decline, breakthrough analgesia within the first 48 hours, and ICU and hospital length of stay.
Among 121 patients randomized (median age, 69 years; 19 women 15.8%), 120 completed the trial. Patients treated with IV acetaminophen had a significant reduction in delirium (10% vs 28% placebo; difference, -18% 95% CI, -32% to -5%; P = .01; HR, 2.8 95% CI, 1.1-7.8). Patients receiving dexmedetomidine vs propofol had no significant difference in delirium (17% vs 21%; difference, -4% 95% CI, -18% to 10%; P = .54; HR, 0.8 95% CI, 0.4-1.9). There were significant differences favoring acetaminophen vs placebo for 3 prespecified secondary outcomes: delirium duration (median, 1 vs 2 days; difference, -1 95% CI, -2 to 0), ICU length of stay (median, 29.5 vs 46.7 hours; difference, -16.7 95% CI, -20.3 to -0.8), and breakthrough analgesia (median, 322.5 vs 405.3 µg morphine equivalents; difference, -83 95% CI, -154 to -14). For dexmedetomidine vs propofol, only breakthrough analgesia was significantly different (median, 328.8 vs 397.5 µg; difference, -69 95% CI, -155 to -4; P = .04). Fourteen patients in both the placebo-dexmedetomidine and acetaminophen-propofol groups (46% and 45%) and 7 in the acetaminophen-dexmedetomidine and placebo-propofol groups (24% and 23%) had hypotension.
Among older patients undergoing cardiac surgery, postoperative scheduled IV acetaminophen, combined with IV propofol or dexmedetomidine, reduced in-hospital delirium vs placebo. Additional research, including comparison of IV vs oral acetaminophen and other potentially opioid-sparing analgesics, on the incidence of postoperative delirium is warranted.
ClinicalTrials.gov Identifier: NCT02546765.
Postoperative delirium is common in elderly cardiac surgery patients. It is multifactorial and is influenced by the patient's baseline status and the nature of the medical and surgical interventions ...that the patient receives. Some of these factors are potentially modifiable, including postoperative sedation and analgesia protocols. This study has been designed to evaluate the effectiveness of postoperative intravenous acetaminophen in conjunction with either dexmedetomidine or propofol in decreasing the incidence of delirium.
This is a prospective, randomized, placebo-controlled, double-blinded, factorial trial that includes patients who are at least 60 years old and who are undergoing cardiac surgeries involving cardiopulmonary bypass, including coronary artery bypass graft (CABG) and combined CABG/valve surgeries. Patients are randomly assigned to receive one of four postoperative analgesic-sedation regimens: (1) acetaminophen and dexmedetomidine, (2) acetaminophen and propofol, (3) dexmedetomidine and placebo, or (4) propofol and placebo. The primary outcome, incidence of delirium, will be assessed with the Confusion Assessment Method (CAM or CAM-ICU). The secondary outcome, postoperative cognitive decline, will be assessed with the Montreal Cognitive Assessment. Additional secondary outcomes, including duration of delirium, postoperative analgesic requirement, length of stay, and incidence of adverse events, will also be reported. Data will be analyzed in 120 randomly assigned patients who received at least one dose of the study medication(s) on a modified intention-to-treat basis.
This study has been approved by the institutional review board at Beth Israel Deaconess Medical Center, and the trial is currently recruiting. This study will systematically examine the implications of modification in postoperative sedative/analgesic protocols after cardiac surgery, specifically for short- and long-term cognitive outcomes. Any positive outcomes from this study could direct simple yet effective practice changes aimed to reduce morbidity.
ClinicalTrials.gov Identifier: NCT02546765 , registered January 13, 2015.
This 2007 symposium of the Canadian Association of University Surgeons brought together surgeons from a number of jurisdictions to discuss the challenges and opportunities that reduced physician work ...hours will bring to the care of the surgical patient. Dr. Brian Taylor, president of the association, underscored the need to find a balance between the benefits of diminished workloads/work hours and the loss of continuity of care. He opined that Canada needs to learn from our European colleagues’ experience. Dr. Per-Olof Nyström, professor of surgery, presented the modern Swedish model of surgical care, which had to be developed as a consequence of the European Union’s legal restrictions on the amount of time an individual surgeon may work. Sweden employs a team-based shared-care model driven by the individual surgeon’s expertise rather than the “village factory” model of the multiskilled, multitasking approach of surgical care more prevalent in Canada. Dr. Chris de Gara, secretary treasurer of the association, presented the evidence base for (and against) work-hour restrictions and how well-designed systems can ensure effective continuity of care. Dr. Stewart Hamilton illustrated how one such system for the delivery of the emergency general surgical services has evolved at the University of Alberta Hospital, which demonstrated its effectiveness in providing quality surgical continuity of care. Dr. Debrah Wirtzfeld underscored the importance of trainee lifestyle and how modern Web-based technologies can ensure reduced errors with the implementation of a “sign-out” system.
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