Long-term continuous infusion of labetalol

Hemodynamic Safety of Continuous Infusion Labetalol Versus Esmolol Combination Therapies for Type B Aortic Dissections

BACKGROUND

Medical management for type B aortic dissections (TBADs) require aggressive blood pressure and heart rate control to minimize further dissection extension and to restore perfusion to vital organs. Current guidelines recommend β-blockers (BB) as first-line therapy, however do not differentiate an ideal agent for use.

OBJECTIVE

This study evaluated the hemodynamic safety of continuous infusion labetalol compared to esmolol combination (EC) therapies for TBADs.

METHODS

This single-center, retrospective analysis identified patients with a TBAD who received high dose continuous intravenous labetalol (HD-CIVL) or EC therapies. Patients who received HD-CIVL or EC therapies for a minimum of 2 hours, during which a minimum of 4 blood-pressure readings were recorded, were included. The primary end point was the incidence of hemodynamic instability with the use of HD-CIVL versus EC therapies.

RESULTS

A total of 20 patients receiving HD-CIVL and 22 patients receiving EC therapy were included in the analysis. Ten (50%) of patients receiving HD-CIVL and 7 (32%) of patients receiving EC therapies met the clinical definition of hemodynamic instability (P = .23). Patients experiencing hemodynamic instability were all due to hypotension, with one also being due to bradycardia. Over half the patients in both groups had discontinued therapy ( P = .06) and were administered bolus fluids (P = .27). Only one patient receiving HD-CIVL required vasopressor administration while none in the EC group (P = .48).

CONCLUSION

Our study suggests that HD-CIVL is associated with a nonstatistical significant higher incidence of hemodynamic instability compared to an EC regimen in TBADs. Further studies are warranted in this patient population.

Safety of high-dose intravenous labetalol in hypertensive crisis

Purpose

The study assesses the safety of high-dose intravenous (i.v.) labetalol in adults.

Methods

This is a retrospective administrative record review of 28 hospitals in one health care system, from October 2010 through October 2015. Patients were included if they received 300 mg of i.v. labetalol within a 24-hour period. Vital signs, adverse events and cumulative medication doses were obtained for up to 24 hours while on labetalol. Adverse events were defined as any systolic blood pressure measurement less than 90 mm Hg or heart rate less than 60 beats per minute.

Results

We analyzed the records of 188 patients who received i.v. labetalol at higher than the maximum recommended dose of 300 mg. The mean dose of labetalol was 996 mg (range 300 to 4465 mg). The cumulative labetalol dose was not associated with adverse safety outcomes (p = 0.428), although eighty-one patients (44.3%) experienced adverse events. Sixty-six patients (36.5%) developed bradycardia and 34 patients (18.6%) developed hypotension. Only five patients (2.7%) required a rescue agent for refractory adverse events.

Conclusion

A retrospective review of high-dose i.v. labetalol hydrochloride with doses greater than 300 mg in 24 hours observed a high rate of bradycardia and hypotension, but the study found that these events rarely caused clinically significant hemodynamic compromise and was not statistically associated with adverse events.

Comparing Labetalol and Nitroglycerine on Inducing Controlled Hypotension and Intraoperative Blood Loss in Rhinoplasty: A Single-Blinded Clinical Trial

Background

Uncontrolled bleeding during surgery is one of the main predisposing factors for failure of the surgeon and complications following rhinoplasty. The current study aimed at comparing the effects of nitroglycerine and labetalol on the induction of controlled hypotension and bleeding volume during septorhinoplasty.

Methods

The current randomized, controlled, clinical trial enrolled 60 patients candidate for septorhinoplasty at Firoozgar hospital in Tehran, Iran, in 2 equal groups receiving either 0.1 to 1 mcg/kg/minute nitroglycerine or 2 to 4 mg/minute labetalol to achieve a mean arterial blood pressure of about 60 to 65 mmHg. In case the targeted blood pressure was not achieved, isoflurane was added. Degree of bleeding was evaluated by the volume of suctioned blood and the blood remaining in surgical gauzes. Additionally, the surgeon's satisfaction with the surgical field was evaluated by a scoring system. The collected data were, then, compared between the study groups by the statistical methods.

Results

Based on the current study findings, systolic (P < 0.001), diastolic (P = 0.002), and the mean arterial blood pressures (P < 0.001) were significantly lower in the nitroglycerine group. Ninety percent of the patients in the labetalol group received isoflurane to achieve the targeted blood pressure defined as controlled hypotension. There was no significant difference between the groups regarding the volume of bleeding (P = 0.75); however, the surgeons were more satisfied with nitroglycerine than labetalol (P < 0.001).

Conclusions

It was concluded that nitroglycerine had a better effect, in comparison to labetalol, on inducing the controlled hypotension in septorhinoplasty.

Labetalol infusion for refractory hypertension causing severe hypotension and bradycardia: an issue of patient safety

Incremental doses of intravenous labetalol are safe and effective and, at times, such therapy may need to be augmented by a continuous infusion of labetalol to control severe hypertension. Continuous infusions of labetalol may exceed the recommended maximum daily dose of 300 mg on occasion. We report a case in which hypertension occurring after an abdominal aortic aneurysm repair, initially responsive to intermittent intravenous beta-blockade, became resistant to this therapy leading to the choice of an intravenous labetalol infusion as the therapeutic option. The labetalol infusion resulted in a profound cardiovascular compromise in this postoperative critically ill patient. While infusions of labetalol have successfully been used, prolonged administration in the intensive care unit requires vigilance and the establishment of a therapeutic rationale/policy for interventions, such as the ready availability of glucagon, beta-agonists, phosphodiesterase inhibitors, insulin, and vasopressin when severe cardiovascular depression occurs.