The main finding of this feasibility trial was that PCS was safe and generated good operating conditions during the procedures. In addition, PCS with propofol and alfentanil for SVP implantation resulted in low self-reported pain perception and high patient satisfaction. To the best of our knowledge, no prior study has examined PCS with propofol and alfentanil in the context of SVP implantation.
Safety for procedural sedation is crucial and has been addressed in several guidelines [7, 8]. The concept of PCS was first described in 1989 . Since then, the use of PCS has been described in several clinical settings and with different sedative and analgesic regimens . PCS with propofol is regarded as a safe technique that reduces the risk of oversedation compared to CCS . PCS with propofol and alfentanil has been used for procedural sedation in gynecological and endoscopic settings. However, data regarding respiratory safety are contradictory. PCS with a combination of propofol and alfentanil was shown to facilitate completion of gynecological operative procedures compared to propofol alone; however, respiratory status was compromised. In contrast, it was found to have no respiratory adverse effects in the setting of endoscopic retrograde cholangiopancreatography [10, 11]. In the present trial, alfentanil at 0.025 mg/dose was associated with limited episodes of bradypnea in four patients, without oxygen desaturation or the need for mechanical ventilation, suggesting that it is safe regarding respiratory adverse events. No AE´s related to heart rate and blood pressure were registered.
Opioids play a crucial role in the relief of procedural pain. Preprocedural buccal administration of fentanyl as well as short-acting intravenous remifentanil has been shown to decrease patients’ pain perception during SVP implantation [12, 13]. In the present trial, the overall perception of pain was low, and 80% of the patients experienced pain of 3 or less on the 11-point NRS during SVP implantation. Furthermore, the satisfaction with pain management was high. This trial suggests a somewhat lower degree of pain perception in SVP implantation with PCS than with LA only.
Interestingly, self-administered doses varied substantially, ranging from 0-27 ml, suggesting large inter-individual differences in sedative and analgesic requirements. This is consistent with previous findings in which PCS with midazolam and fentanyl were used for tunneled venous access . More than a third of eligible patients declined participation, as they considered sedation for a presumably minor procedure unnecessary or wanted to drive their vehicles home after discharge. This not only generated selection bias, but might reflect patients’ varying needs for sedation and analgesia, as mentioned above. The challenge lies in identifying patients according to their sedative needs before the procedure begins. As suggested earlier, the likely determinants for self-administered anxiolytics seem to be the patient’s own assessment of his or her needs in a shared decision-making process . A preoperative consultation might therefore suffice to clarify the patient’s needs and to agree on an individualized analgesic strategy.
Patient satisfaction with care and staff contact was very high. Patient satisfaction is challenging to quantify, and patient-related experience measures (PREM) are key to providing good patient-centered clinical care and allowing comparison of clinical routines . Unfortunately, no appropriate validated questionnaire for sedation in minor procedures (such as central venous access) exists, leading to the pragmatic approach of using established methods, though not validated, to facilitate comparison .
The present trial has limitations that must be mentioned. First, with a small sample size, rare adverse events were likely missed. However, the primary goals of the trial were to assess PCS during SVP implantation and to provide guidance for future trials. Second, the lack of a validated PREM for central venous access insertion limits proper tools for measuring patient satisfaction and comparison with other studies, which must be addressed in the future.