Patients diagnosed with cancer experience anxiety and stress, which can often interfere with sleep. A patient survey gave out 65 aromasticks (personal inhalers) over a 13-week period to cancer patients at a cancer center in the UK. Two essential oil blends were used, either a combination of bergamot Citrus aurantium var. bergamia (Risso) and sandalwood Santalum austrocaladonicum, or frankincense Boswellia carterii (Birdw.), mandarin Citrus reticulata (Blanco), and lavender L. angustifolia. At least a one point improvement on the Likert Scale Measuring Sleep Quality was shown by 64% of patients, and 94% of participants who used the aromasticks said they would continue to do so. (5)
College students with self-reported sleep issues saw more improved sleep with nightly lavender L. angustifolia essential inhalation for five nights and sleep hygiene practices than the students who used sleep hygiene practices alone. The effects continued to be seen at the two-week follow up interview. (3)
Lowering Nausea and Vomiting
Several studies have been published showing good results for reducing nausea and vomiting with essential oil inhalation.
Inhalation of ginger Zingiber officinale (Roscoe) essential oil was shown to lower nausea and vomiting in adult post-operative patients. (7) However, when a blend of ginger Z. officinale, lavender L. angustifolia, peppermint Mentha xpiperita (L.), and spearmint Mentha spicata (L.) essential oil was used via inhalation to relieve nausea and vomiting in post-operative children, there was no statistical difference between aromatherapy and the saline placebo group. (6)
In a study assessing the effectiveness of ginger Z. officinale essential oil to relieve chemotherapy induced nausea and vomiting in breast cancer patients, researchers found nausea was relieved in the acute phase, but not for the duration of the five-day treatment. Also, the aromatherapy group reported better global health status and improvement in appetite loss. (8)
Lemon Citrus limon (Risso) essential oil was shown to lower nausea and vomiting of pregnant women over a four-day treatment period. The women in the aromatherapy group were encouraged to inhale the provided lemon C. limon essential oil at the first signs of nausea. (9)
Situational Stress and Anxiety
One of the primary focuses in research on essential oil inhalation has been around situational stress and anxiety.
Test Anxiety in Students
An Iranian study showed inhaling tuberose Polianthes tuberosa (L.) essential oil on a handkerchief for 15 minutes lowered anxiety in seventh-grade students while taking an exam, compared to the control group who inhaled saline solution. (10)
Pre-Operative and Post-Operative Patients
Several studies have shown aromatherapy inhalation lowers anxiety in patients about to undergo, or recovering from, different types of surgery. However, the results of these studies do show mixed results, which underlines the need for more research to better understand which factors affect aromatherapy outcomes.
Chest tube removal after cardiac surgery is a painful procedure which also causes anxiety. Lavender L. angustifolia essential oil inhalation, as well as a combination of lavender L. angustifolia essential oil inhalation and cold application, lowered pain and anxiety levels during the procedure and 15 minutes afterwards. (12) Inhalation of 2 drops of lavender L. angustifolia essential oil for 20 minutes lowered anxiety and cortisol levels in open heart surgery candidates. (11)
However, another study had coronary bypass patients inhale a 2% lavender L. angustifolia solution for three days post-surgery. Anxiety was lowered in the aromatherapy group, but there was no statistical difference between the aromatherapy and control groups. (14)
Inhalation of bitter orange Citrus aurantium (L.) essential oil prior to a bone marrow aspiration procedure for patients with chronic myeloid leukemia lowered anxiety, blood pressure, and cardiac and respiratory frequency. The effects in the aromatherapy group were more effective than the diazepam and control groups. (13)
However, a placebo-controlled, double-blind study did not find any statistical differences in the pain levels of children and adolescents undergoing stem cell infusion after bergamot C. aurantium var. bergamia essential oil inhalation. Also, nausea and anxiety levels were greater in the aromatherapy group one hour post procedure. The researchers felt perhaps a follow-up study would examine cutaneous aromatherapy applications and compare results. (17)
Lavender L. angustifolia and clary sage Salvia sclarea (L.) essential oils were both examined for lowering anxiety in female patients with urinary incontinence about to undergo a urodynamic exam. Interestingly, while both inhalation with clary sage S. sclarea or lavender L. angustifolia essential oil lowered respiratory rate, lavender essential oil tended to increase blood pressure in the situation, while clary sage S. sclarea lowered it. Based on these results, the researchers felt clary sage S. sclarea was more effective at lowering anxiety during the exam than lavender L. angustifolia. (16)
Night-shift Medical Staff
The anxiety level of nurses was shown to be lowered, over several days, by wearing a vial of 3% lavender L. angustifolia essential oil on the right chest of their uniforms during their shift. (15) Another study showed a 30-minute rest with lavender essential oil inhalation at the end of their shift improved the effects seen on endothelial function of night shift medical staff. (18)
Pregnancy, Labor and Delivery, and Post-Partum
The use of aromatherapy to support mothers during pregnancy, labor and deliver, and post-partum has been an important and increasing topic of discussion. Research focusing on establishing safe and effective best-practices guidelines is important. Several studies have focused on the effects of aromatherapy inhalations.
A pilot study evaluated the effects of aromatherapy inhalation and aromatherapy M hand technique on post-partum depression with a combination of rose Rosa damascena (Mill.) and lavender L. angustifolia essential oils in a 2% dilution. Participants received 15-minute aromatherapy sessions twice a week for four consecutive weeks. While there was a difference between the aromatherapy and control groups at the beginning of the study, at the mid-point and end of the study, the aromatherapy groups had significant improvements over the control group on the Edinburgh Postnatal Depression Scale (EPDS) and Generalized Anxiety Disorder Scale (GAD-7). (19)
Another study also evaluated aromatherapy support for post-partum depression using inhalations with 3 drops lavender L. angustifolia essential oil every eight hours for three weeks beginning right after delivery. Participants received routine care, and were followed-up with by telephone using the 21-item Depression, Anxiety, and Stress Scale and the Edinburgh Stress, Anxiety, and Depression Scale. At the two-week, one-month, and three-month check in points, all aromatherapy participants showed lowered mean stress, anxiety, and depression scores as compared to the control group. (20)