Anna Missir

Vitreoretinal surgery (VRS) is one of the most widely performed precise procedures in ophthalmic surgery; the majority of cases are carried out under regional anaesthesia (RA) only. However, in specific situations (such as when the patient fails to cooperate with the operator for various reasons), general anaesthesia (GA), alone or in combination with GA (combined general–regional anaesthesia, CGR), is the only safe way to perform VRS. While monitoring the efficacy of an intraoperative rescue opioid analgesia (IROA) during surgery (assessing the adequacy of anaesthesia (AoA)) may be challenging, the surgical pleth index (SPI) is a useful tool for detecting the reaction to noxious stimuli and allows for the rational titration of opioid analgesics (AO) during surgery. The current study investigated the influence of the SPI-based titration of fentanyl (FNT) in combination with various pre-emptive analgesia (PA) techniques on intraoperative pain perception during various stages of VRS performed under AoA. A total of 176 patients undergoing VRS under GA were enrolled in the study. They were randomly assigned to one of the five following study arms: Group GA (control group)—patients who received general anaesthesia alone; Group PBB—GA with preprocedural peribulbar block (with 0.5% bupivacaine and 2% lidocaine); Group T—GA with preventive, topical 2% proparacaine; Group M—GA with a preprocedural intravenous infusion of 1.0 g of metamizole; and Group P—GA with a preprocedural intravenous infusion of 1.0 g of paracetamol. The whole procedure was divided in four stages: Stage 1 and 2—preoperative assessment, PA administration, and the induction of GA; Stage 3—intraoperative observation; Stage 4—postoperative observation. the SPI values were monitored during all stages. The occurrence of nociception (expressed as ∆SPI >15) during various manipulations in the surgical field was observed, as were cumulative doses of rescue analgesia, depending on the PA administered. During the course of VRS, rescue FNT doses varied depending on the stage of surgery and the group investigated. The majority of patients, regardless of their group allocation, needed complementary analgesia during trocar insertion, with Group GA patients requiring the highest doses. Likewise, the highest cumulative doses of IROA were noted during endophotocoagulation in Group GA. Preventive PBB and topical anaesthesia were proven to be most efficient in blunting the response to speculum installation, while topical anaesthesia and paracetamol infusion were shown to be more efficient analgesics during endophotocoagulation than other types used PA. In the performed study, none of the PA techniques used were superior to GA with FNT dosing under the SPI with respect to providing efficient analgesia throughout the whole surgery; there was a necessity to administer a rescue OA dose in both the control and investigated groups.

Vitreoretinal surgeries require the administration of general anesthesia (GA) in selected groups of patients. The administration of intraoperative rescue narcotic analgesia (IRNA) during GA poses the risk of postoperative nausea and vomiting (PONV). The surgical pleth index (SPI), a crucial component of the adequacy of anesthesia (AoA) guidance of GA, optimizes the intraoperative titration of IRNA. The current analysis evaluated the risk factors for the occurrence of PONV and the oculo-cardiac reflex (OCR) in patients undergoing pars plana vitrectomy (PPV) under AoA guidance. In total, 175 patients undergoing PPV were randomly allocated to receive either GA with SPI-guided IRNA administration using fentanyl alone or in addition to different preoperative analgesia techniques. Any incidence of PONV or OCR was recorded. Obesity, overweight, smoking status, motion sickness, postoperative intolerable pain perception, female gender, fluid challenge and arterial hypertension did not correlate with an increased incidence of PONV or OCR under AoA guidance. Diabetes mellitus, regardless of insulin dependence, was found to correlate with the increased incidence of PONV. The AoA regimen including SPI guidance of IRNA presumably created similar conditions for individual subjects, so no risk factors of the occurrence of PONV or OCR were found, except for diabetes mellitus. We recommend using AoA guidance for GA administration to reduce OCR and PONV rates.

Inadequate intraoperative analgesia causes the deterioration of the condition of the surgical field (CSF) as a result of hemodynamic instability. Analgesia monitors are used to guide remifentanil) infusion to optimize intraoperative analgesia. The main aim of the current randomized controlled trial was to investigate the potential advantages of intraoperative analgesia monitoring using surgical Pleth index (SPI)- or pupillometry (PRD)-guided remifentanil administration for managing the volume of total intraoperative blood loss (TEIBL), CSF, and length of operation (LOP) in comparison with the standard practice in patients undergoing endoscopic sinus surgery (ESS). The 89 patients in our study were grouped as follows: 30 patients were assigned to the general analgesia (GA) group, 31 patients were assigned to the SPI group, and 28 patients were assigned to the PRD group. The speed of remifentanil infusion was accelerated by 50% when SPI, PRD, or BSS were increased by >15 points, >5%, or >2, respectively, in adjacent groups until their normalization. The SPI group showed significantly lower TEIBL in comparison to the GA group (165.2 ± 100.2 vs. 283.3 ± 193.5 mL; p < 0.05) and a higher mean arterial pressure (MAP; 73.9 ± 8 vs. 69.2 ± 6.8 mmHg; p < 0.05). In the PRD group, a shorter LOP compared with the GA group was observed (63.1 ± 26.7 min vs. 82.6 ± 33.1 min; p < 0.05). It was noted that the PRD group had a lower total remifentanil consumption than the SPI group (1.3 ± 1.4 vs. 1.8 ± 0.9 mg; p < 0.05). In ASA I-III patients undergoing ESS, intraoperative monitoring based on state entropy and SPI values can optimize the CSF and reduce TEIBL, whereas monitoring based on state entropy and PRD measurements can optimize the cost effectiveness of anesthetic drugs and the use of the operation room.

The intraprocedural immobilization of selected subsets of patients undergoing pars plana vitrectomy (PPV) requires the performance of general anesthesia (GA), which entails the intraoperative use of hypnotics and titration of opioids. The Adequacy of Anesthesia (AoA) concept of GA guidance optimizes the intraoperative dosage of hypnotics and opioids. Pre-emptive analgesia (PA) is added to GA to minimize intraoperative opioid (IO) usage. The current additional analysis evaluated the advantages of PA using either COX-3 inhibitors or regional techniques when added to AoA-guided GA on the rate of presence of postoperative nausea and vomiting (PONV), oculo-emetic (OER), and oculo-cardiac reflex (OCR) in patients undergoing PPV. A total of 176 patients undergoing PPV were randomly allocated into 5 groups: (1) Group GA, including patients who received general anesthesia alone; (2) Group T, including patients who received preventive topical analgesia by triple instillation of 2% proparacaine 15 min before induction of GA; (3) Group PBB, including patients who received PBB; (4) Group M, including patients who received PA using a single dose of 1 g of metamizole; (5) Group P, including patients who received PA using a single dose of 1 g of acetaminophen. The incidence rates of PONV, OCR, and OER were studied as a secondary outcome. Despite the group allocation, intraoperative AoA-guided GA resulted in an overall incidence of PONV in 9%, OCR in 12%, and OER in none of the patients. No statistically significant differences were found between groups regarding the incidence of OCR. PA using COX-3 inhibitors, as compared to that of the T group, resulted in less overall PONV (p < 0.05). Conclusions: PA using regional techniques in patients undergoing PPV proved to have no advantage when AoA-guided GA was utilised. We recommend using intraoperative AoA-guided GA to reduce the presence of OCR, and the addition of PA using COX-3 inhibitors to reduce the rate of PONV.

In patients undergoing colonoscopy procedures (CPs), inadequate dosing of hypnotic drugs (HD) and opioid analgesics (OA) during intravenous sedoanalgesia (ISA) may lead to intraprocedural awareness with recall (IAwR), intraprocedural (IPP) and postprocedural pain (PPP), as well as postoperative nausea and vomiting (PONV). The aim of this study was to evaluate whether the titration of HD and OA based on the observance of changing values of state entropy (SE) and surgical pleth index (SPI) (adequacy of anesthesia—AoA), state entropy alone, or standard practice may reduce the number of adverse events. One hundred and fifty-eight patients were included in the final analysis. The rate of IAwR and IPP was statistically more frequent in patients from the C group in comparison with the AoA and SE groups (p < 0.01 and p < 0.05, respectively). In turn, the rate of PPP, PONV, and patients’ and operators’ satisfaction with ISA between groups was not statistically significant (p > 0.05). Changes in hemodynamic parameters, demand for HD, and OA were statistically significant, but of no clinical value. In patients undergoing CPs under ISA using propofol and FNT, as compared to standard practice, intraprocedural SE monitoring reduced the rate of IAwR and IPP, with no influence on the rate of PPP, PONV, or patients’ and endoscopists’ satisfaction. AoA guidance on propofol and FNT titration, as compared to SE monitoring only, did not reduce the occurrence of the aforementioned studied parameters, imposing an unnecessary extra cost.

Background and Objectives: Although vitreoretinal surgery (VRS) is most commonly performed under regional anaesthesia (RA), in patients who might be unable to cooperate during prolonged procedures, general anaesthesia (GA) with intraprocedural use of opioid analgesics (OA) might be worth considering. It seems that the surgical pleth index (SPI) can be used to optimise the intraprocedural titration of OA, which improves haemodynamic stability. Preventive analgesia (PA) is combined with GA to minimise intraprocedural OA administration. Materials and Methods: We evaluated the benefit of PA combined with GA using SPI-guided fentanyl (FNT) administration on the incidences of PIPP (postprocedural intolerable pain perception) and haemodynamic instability in patients undergoing VRS (p < 0.05). We randomly assigned 176 patients undergoing VRS to receive GA with SPI-guided FNT administration alone (GA group) or with preventive topical 2% proparacaine (topical anaesthesia (TA) group), a preprocedural peribulbar block (PBB) using 0.5% bupivacaine with 2% lidocaine (PBB group), or a preprocedural intravenous infusion of 1.0 g of metamizole (M group) or 1.0 g of paracetamol (P group). Results: Preventive PBB reduced the intraprocedural FNT requirement without influencing periprocedural outcomes (p < 0.05). Intraprocedural SPI-guided FNT administration during GA resulted in PIPP in 13.5% of patients undergoing VRS and blunted the periprocedural effects of preventive intravenous and regional analgesia with respect to PIPP and haemodynamic instability. Conclusions: SPI-guided FNT administration during GA eliminated the benefits of preventive analgesia in the PBB, TA, M, and P groups following VRS.