Effect of Nebulized Verapamil on Oxygenation in Chronic Obstructive Pulmonary Disease (COPD) Patients Admitted to the Intensive Care Unit

Abstract

Background: Many pharmacological and behavioral therapies have been investigated to improve oxygenation in the intensive care unit (ICU). In patients with chronic obstructive pulmonary disease (COPD), the purpose of therapy is to correct the ventilation perfusion (V/Q) mismatch. Agents, such as calcium blockers, can affect both ventilation and vasculature. The inhalation route allows a more rapid achievement of therapeutic effects with few systemic side effects. Therefore, the present study aimed to investigate the effect of nebulized verapamil on oxygenation in COPD patients.

Materials and methods: In this double-blind, randomized clinical trial, twenty hypoxic COPD patients, admitted to ICU, were treated with 10 mg of verapamil twice daily for three days. Also, twenty patients with COPD, who were matched in terms of age, sex, and severity of the disease, were enrolled in the control group and received nebulized normal saline. The oxygenation parameters were compared using an arterial blood gas (ABG) test before and after the intervention.

Results: The mean oxygen saturation was 91.2%±12.15 before verapamil inhalation, which increased to 95.75%±14.57 after receiving nebulized verapamil (P<0.05). Also, correction of blood pH, blood oxygen pressure, and oxygen ratio (PaO₂/FIO₂) were higher in patients receiving verapamil, compared to the control group. The length of hospital stay was similar in the two groups. During the first three days, 30% of patients in the verapamil group and 20% of patients in the control group were intubated.

Conclusion: Our results indicated that verapamil inhalation increased oxygen saturation and accelerated extubation in patients with COPD.

Keywords: Calcium Channel Blockers; Chronic Obstructive Pulmonary Disease; Oxygenation; Verapamil.

Figure 1.

The modification obtained in SO2 among verapamil vs. control group during three days of follow up. O2 saturation significantly increased after verapamil inhalation in all three days. B: before; A: after, 1-B: before first administration; 1-A: after first administration; 2-B: before second administration; 2-A: after second administration; 3-B: before third administration; 3-A: after third administration.

Figure 2.

The amount of changes obtained in the both study groups. After three days Pa O2 significantly changed in the verapamil group

Figure 3.

Changes rate in CO2 pressure among verapamil vs. saline patients. Base line PCO2 was not differing between groups. After the first verapamil inhalation PCO2 decreased significantly. B: before; A: after, 1-B: before first administration; 1-A: after first administration; 2-B: before second administration; 2-A: after second administration; 3-B: before third administration; 3-A: after third administration.

Figure 4.

The average modification of O2 saturation based on normalization of FIO2 within three days of administration. PF ratio indicated significant increase in the patients received verapamil.

Figure 5.

Effects of inhaled verapamil versus systemic verapamil. Aerosolized verapamil affects the both vascular as well as alveoli. Thus the well ventilated of well perfused regions result in correction of V/Q mismatch. While in systemic use, the impact of verapamil on vasculature network rather than pulmonary space would increase V/Q mismatch(22).