Comparison of simultaneous and sequential administration of fentanyl-propofol for surgical abortion: a randomized single-blinded controlled trial

Propofol lipid emulsion (PLE) is a nanosized sedative, and it is used with a combination of salted antalgic prodrug, fentanyl citrate (FC). To illustrate the synergistic effect of mixing, we compared the sedation/analgesia resulting from simultaneous and sequential administration in surgically induced abortion (No. ChiCTR-IPC-15006153). Simultaneous group showed lower bispectral index, blood pressure, and heart rate, when cannula was inserted into the uterus. It also showed less frequency of hypertension, sinus tachycardia, movement, pain at the injection site, and additional FC. Therefore, premixing of PLE and FC enhanced the sedation and analgesia; stabilized the hemodynamics; lessened the incidence of movement and injection pain; and reduced the requirement of drugs.

Optimizing Outcomes for Mechanically Ventilated Patients in an Era of Endovascular Acute Ischemic Stroke Therapy

Endovascular mechanical thrombectomy is a new standard of care for acute ischemic stroke (AIS). The majority of these patients receive mechanical ventilation (MV), which has been associated with poor outcomes. The implication of this is significant, as most neurointerventionalists prefer general compared to local anesthesia during the procedure. Consequences of hemodynamic and respiratory perturbations during general anesthesia and MV are thought to contribute significantly to the poor outcomes that are encountered. In this review, we first describe the unique risks associated with MV in the specific context of AIS and then discuss evidence of brain goal-directed approaches that may mitigate these risks. These strategies include an individualized approach to hemodynamic parameters (eg, adherence to a minimum blood pressure goal and adequate volume resuscitation), respiratory parameters (eg, arterial carbon dioxide optimization), and the use of ventilator settings that optimize neurological outcomes (eg, arterial oxygen optimization).

Remifentanil and propofol undergo separation and layering when mixed in the same syringe for total intravenous anesthesia

BACKGROUND

Propofol and remifentanil can be combined to deliver total intravenous anesthesia (TIVA). Propofol and remifentanil are sometimes mixed in the same syringe. Since remifentanil is a solution and propofol is an emulsion, we hypothesized that they would separate over time when mixed in the same syringe.

METHODS

Nine 60-ml polypropylene syringes were prepared as follows: Group A: 1.25 ml of remifentanil solution (1 mg·ml(-1) ) was added to 48.75 ml of propofol (10 mg·ml(-1) ) in three syringes. Group B: 2.5 ml of remifentanil (1 mg·ml(-1) ) was added to 47.5 ml of propofol (10 mg·ml(-1) ) in three syringes. Group C: 5 ml of remifentanil (1 mg·ml(-1) ) was added to 45 ml of propofol (10 mg·ml(-1) ) in three syringes. The remifentanil lyophilized powder was reconstituted with sterile water and added to the propofol by injection through the port on the bottom of the syringe. The syringe was then inverted five times in succession to mix the drugs. The syringes were mounted in an upright vertical position (plunger on top, port on bottom) with wire on a pegboard. Samples of the mixture were taken from the bottom port (via a 3-way stopcock) and from the top of the syringe (via a stopcock on an 18-gauge needle placed 5 mm through the plunger) at the following time intervals (min) from baseline: T0, T10, T30, T60, T120, T180, T240, T300. Remifentanil and propofol were quantified using specific and validated HPLC/MS/MS assays with automated online sample preparation.

RESULTS

Concentrations of remifentanil were significantly greater at the top than the bottom of the syringes in groups A and B. Concentrations of propofol were significantly greater at the bottom than the top of the syringes in all groups.

CONCLUSION

Our data indicate that remifentanil solution and propofol emulsion are immiscible: remifentanil separates from propofol and rises to the top. Thus, concentrations of remifentanil and propofol delivered to patients from the same syringe during TIVA are not those expected and cannot be reliable. Remifentanil and propofol should be administered in separate syringes when used in combination for TIVA.