The influence of positive end-expiratory pressure on surgical field conditions during functional endoscopic sinus surgery

Hypotensive Levels on Endoscopic Sinus Surgery Visibility: A Randomized Non-Inferiority Trial

OBJECTIVE

Optimization of endoscopic sinus surgery (ESS) conditions is a common focus of interest for otolaryngologists and anesthesiologists. Relying on hypotension alone to achieve a bloodless field may not without risks. We sought to determine whether ESS is feasible in the context of moderate hypotension.

METHODS

This randomized non-inferiority trial enrolled 96 adult patients who were to undergo ESS. The patients were divided into two groups: Controlled hypotension group (n = 48, MAP reduction to 55-65 mmHg, minimum of 60% of baseline blood pressure) or Individualized hypotension group (n = 48, MAP reduction to 75-80% of baseline blood pressure). All participants were placed in 10° reverse Trendelenburg position during ESS, and cottonoid patties dammed with epinephrine was recommended to clear the operative field of bleeding. The two groups were compared according to Boezaart grading scale (BS) score, estimated blood loss, blood loss rate, arterial lactate level and postoperative recovery.

RESULTS

Both levels of intraoperative hypotension (62.2 ± 2.3 mmHg vs. 74.0 ± 2.8 mmHg) provided acceptable surgical conditions with no difference in mean BS scores [2.00 (1.88-2.33) vs. 2.00 (1.85-2.45), p = 0.926]. The 95% CI for median value differences in mean BS scores is lower than the preset non-inferiority margin. There were no differences in blood loss rate and estimated blood loss between two groups (p > 0.05) Postoperative arterial lactate and Ramsay sedation scores were significantly different between the two groups (p < 0.05).

CONCLUSIONS

In ESS, both levels of intraoperative hypotension, combined with position adjustment and low-concentration adrenaline to constrict nasal mucosal blood vessels, provided acceptable surgical conditions.

LEVEL OF EVIDENCE

2 Laryngoscope, 134:569-576, 2024.

Positive End-Expiratory Pressure in Rhinoplasty Surgery; Risks and Benefits

Aims

The aim of this study is to evaluate the effect of Positive End Expiratory Pressure (PEEP) on surgical field bleeding and its respiratory and hemodynamic consequences in rhinoplasty surgeries.

Materials and methods

This single-blind clinical trial performed in Amir Al-Momenin university Hospital in 2018. Seventy cases of rhinoplasty surgery patients Enrolled and were randomized into two groups; intervention (PEEP = 5) and comparison group (PEEP = 0). Surgical field bleeding and arterial oxygen saturation pulmonary dynamics and hemodynamic parameters were evaluated during operation and in post anesthesia care unit. Data were analyzed by SPSS software using descriptive and analytical statistics.

Results

PEEP applying had no negative effect on surgical bleeding as well as surgeon satisfaction, heart rate and blood pressure were similar in two groups. Pulmonary dynamics and oxygenation were stable and within normal values in all cases. The mean peak airway pressure was 17.87 ± 2.24 in the PEEP group and 16.08 ± 3.37 in the ZEEP group (P = 0.029).

Conclusion

applying low level PEEP during anesthesia improved recovery oxygen saturation but had no negative effects on the patient`s hemodynamics, and did not aggravate bleeding and visual clarity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03854-7.

Adequacy of Anesthesia and Pupillometry for Endoscopic Sinus Surgery

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.

Nitrous oxide anesthetic versus total intravenous anesthesia for functional endoscopic sinus surgery

BACKGROUND

Functional endoscopic sinus surgery is a common procedure for sinonasal disease, frequently performed in the outpatient setting. General anesthesia maintained with total intravenous anesthesia (TIVA) with propofol has been shown to give superior surgical conditions compared to inhaled anesthetics. This study evaluated the effects of TIVA versus a predominantly nitrous oxide (N₂ O)-based anesthetic with a low-dose propofol and remifentanil infusion on sinus surgery.

METHODS

Patients were randomized to either a N₂ O-based (nitrous oxide with propofol and remifentanil) or TIVA (propofol and remifentanil without nitrous oxide) group. The surgeon was blinded to the anesthetic technique. Surgical field grading was performed in real time by the otolaryngologist every 15 minutes with the Boezaart grading system.

RESULTS

There were no statistically significant differences between the Boezaart scores, duration of surgery, or estimated blood loss between the two anesthetic techniques. However, the use of N₂ O provided a statistically significant, 38% reduction in time from surgery end to extubation. The TIVA group had significantly decreased mean and median pain scores in the post-anesthesia care unit (PACU). There was no difference in the rate of postoperative nausea and vomiting between the two groups.

CONCLUSION

A N₂ O-based anesthetic for functional endoscopic sinus surgery provides similar intraoperative and postoperative conditions when compared to TIVA, while being superior in terms of time to extubation. Although the TIVA group had significantly decreased pain scores, this did not lead to a decrease in pain medicine received in the PACU, and there was no difference between groups in time to discharge.

LEVEL OF EVIDENCE

1b Laryngoscope, 130:E299-E304, 2020.

Anesthesia for functional endoscopic sinus surgery

PURPOSE OF REVIEW

The present article summarizes anesthetic techniques used during functional endoscopic sinus surgery to decrease bleeding and aid in creating a clear surgical field. The applicable physiology behind these anesthetic techniques is reviewed with emphasis on the effect on bleeding and the surgical field. Deliberate hypotension, reverse Trendelenburg positioning, regional anesthesia, and cerebral monitoring are discussed.

RECENT FINDINGS

There are mixed data as to whether traditional inhalation anesthesia or total intravenous anesthesia is superior with respect to better surgical fields and decreased blood loss. A review of the literature tends to favor total intravenous anesthesia. Cerebral oximetry and transcranial Doppler ultrasound are emerging techniques to monitor cerebral perfusion during deliberate hypotension.

SUMMARY

Total intravenous anesthesia using propofol and remifentanil is the current favored technique for producing deliberate hypotension during endoscopic sinus surgery due to its hemodynamic stability and smooth rapid emergence.

Impact of Controlled Induced Hypotension on Cognitive Functions of Patients Undergoing Functional Endoscopic Sinus Surgery

Background

Controlled induced hypotension guarantees less blood loss and better visibility of the surgical site. The impact of hypotension on post-operative cognitive functions is still being discussed. The objective of this study was to evaluate the effects of controlled induced hypotension on the cognitive functions of patients undergoing functional endoscopic sinus surgery (FESS).

Material/Methods

We allocated 47 patients with a good grade of preoperative cognitive functions evaluated with the Mini-Mental State Examination to 3 groups (1 – mild hypotension, 2 – intermediate hypotension, 3 – severe hypotension) according to the degree of mean intraoperative arterial pressure compared with preoperative blood pressure. Cognitive functions were evaluated preoperatively, 6 h, and 30 h postoperatively with standardized tests: the Stroop Test, Trail Making Test (TMT), and Verbal Fluency Test (VFT). A decrease in the test results and increase in the number of mistakes made were considered an impairment of cognitive functions.

Results

A total of 47 patients (group 1 – mild hypotension – 15, group 2 – intermediate hypotension – 19, group 3 – severe hypotension – 13) were included in the study. A significant decrease was observed in all the 3 groups after Stroop A test 6h postoperatively but it improved 30h postoperatively, without differences between the groups. Neither a significant decrease in the test results nor an increase in the number of mistakes was noted for Stroop B tests, TMT A&B tests and VFT.

Conclusions

The degree of controlled intraoperative hypotension during FESS did not influence the results of psychometric tests.