Effects of nitroglycerin versus labetalol on peripheral perfusion during deliberate hypotension for sinus endoscopic surgery: a randomized, controlled, double-blinded trial

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.

Does preoperative administration of hypotensive agents affect the quality of the surgical field during endoscopic sinus surgery? A triple-blind randomized controlled trial

PURPOSE

Endoscopic sinus surgery (ESS) is a surgical procedure widely used in the treatment of various sinonasal conditions. Excessive bleeding during ESS leads to potentially major complications. The primary aim of this trial was to explore any different effects of bisoprolol and nifedipine on the intraoperative surgical field. In addition, the correlations regarding surgical field state, total blood loss (TBL), mean arterial pressure (MAP), and heart rate (HR) were also examined.

METHODS

A prospective, triple-blinded, randomized, placebo-controlled trial was conducted, including 72 patients between 18 and 65 years of age who underwent ESS. As an indicator of the worst state of the intraoperative surgical field, the Boezaart scale score was used, as evaluated by two surgeons. Appropriate statistical analysis was conducted to explore score comparisons across groups and correlations between vital signs, bleeding, and the operative field state.

RESULTS

No statistically significant difference was found among different intervention groups regarding the worst state of the surgical field (p = 0.367 > 0.05). The Boezaart scale score was positively correlated with TBL (rxy = 0.619, p = 0.000 < 0.001) and MAP (rxy = 0.259, p = 0.028 < 0.05). Furthermore, MAP was positively correlated with HR (rs = 0.254, p = 0.32 < 0.05).

CONCLUSION

Our study demonstrates that preoperative administration of bisoprolol and nifedipine does not affect the worst state of the operative field. However, vital signs seem to either directly or indirectly affect bleeding and operative field state, and agents affecting them are worth exploring further.

Effect of perioperative magnesium sulfate and labetalol infusion on peripheral perfusion and postoperative pain in nasal surgery: a randomized controlled trial

BACKGROUND

Maintenance of adequate peripheral perfusion during controlled hypotension is necessary for patient safety and improved surgical outcomes during controlled hypotension in nasal surgery. The hypothesis of this study was to investigate the effect of perioperative magnesium sulfate and labetalol infusion on peripheral perfusion and postoperative pain in patients undergoing nasal surgery.

METHODS

A total of 50 patients were randomly assigned into two equal groups in this double-blind clinical study: the magnesium sulfate group; received 40 mg/kg loading dose of intravenous (IV) magnesium sulfate followed by 10-15 mg/kg/h continuous IV infusion and the labetalol group; received 0.25 mg/kg loading dose of IV labetalol followed by 0.5-1 mg/kg/h continuous IV infusion to achieve a mean arterial blood pressure (MABP) of = 55-65 mmHg. The primary outcome was to compare the effect of perioperative magnesium sulfate and labetalol infusion on peripheral perfusion during nasal surgery. The secondary outcomes were the assessment of serum lactate, postoperative pain, time to the first call for pethidine (rescue analgesic) and total pethidine consumption.

RESULTS

PPI was comparable between the groups at baseline, intubation, and 5 min. In contrast, magnesium sulfate group had a significantly higher PPI than the labetalol group. The magnesium sulfate group had a significantly higher MABP and heart rate compared to labetalol group. The time to reach the target MABP was significantly prolonged in magnesium sulfate than the labetalol group [21.6 ± 1.7 vs 6.9 ± 1.5] min. VAS scores were significantly lower for 2 hs postoperatively in the magnesium sulfate group than the labetalol group. The time to first call of pethidine was significantly prolonged in the magnesium sulfate group compared to the labetalol group [113.1 ± 5.2 vs 28.2 ± 1.5] min.

CONCLUSIONS

Magnesium sulfate maintains wider PPI and offers better postoperative pain relief compared to labetalol during induced hypotension in nasal surgery.

TRIAL REGISTRATION

Institutional review board approval (ref: 6601/20-12-2020).

CLINICALTRIAL

gov (ref: NCT04688203 , date of registration: 29 -12-2020).

Plethysmographic Peripheral Perfusion Index: Could It Be a New Vital Sign?

The plethysmographic peripheral perfusion index (PPI) is a very useful parameter with various emerging utilities in medical practice. The PPI represents the ratio between pulsatile and non-pulsatile portions in peripheral circulation and is mainly affected by two main determinants: cardiac output and balance between sympathetic and parasympathetic nervous systems. The PPI decreases in cases of sympathetic predominance and/or low cardiac output states; therefore, it is a useful predictor of patient outcomes in critical care units. The PPI could be a surrogate for cardiac output in tests for fluid responsiveness, as an objective measure of pain especially in un-cooperative patients, and as a predictor of successful weaning from mechanical ventilation. The PPI is simple to measure, easy to interpret, and has continuously displayed variables, making it a convenient parameter for detecting the adequacy of blood flow and sympathetic-parasympathetic balance.