The Acute Effect of Chamomile Intake on Blood Coagulation Tests in Healthy Volunteers: A Randomized Trial.

BACKGROUND: Chamomile administration may have desirable effects in the perioperative setting. Current practice, however, discourages perioperative chamomile use due to a theoretical increase in bleeding. Therefore, we evaluated if chamomile acutely (within 4 h of ingestion) prolongs coagulation assays. METHODS: Eight healthy volunteers were randomized to receive 2 interventions in a crossover design: (a) single dose of chamomile extract capsule (500 mg) and (b) single dose of chamomile tea (3 g in 150 mL water). Interventions were separated at least 3 days apart from each other. Blood was sampled pre-ingestion, 2 h post-ingestion, and 4 h post-ingestion for each intervention. The primary outcome was the maximal change in prothrombin time (PT) before vs after each intervention. Secondary outcomes included changes in international normalized ratio, activated partial thromboplastin time, thrombin time, reptilase time, and fibrinogen levels. RESULTS: All 8 subjects completed the study. The average pre-ingestion PT values for tea and capsules were 11.9 (1.1) s and 12.0 (0.9) s, respectively. Tea significantly increased the average maximum PT by 0.7 (0.2) s (P = 0.0078). Extract capsules increased the maximum PT by 0.3 (0.2) s (P = 0.06). Neither PT prolongation met the predefined 10% threshold for clinical significance. No significant changes in secondary outcomes were observed. CONCLUSIONS: Chamomile tea ingestion prolongs PT. However, the clinical significance of this is unclear at this time and warrants further investigation. ClinicalTrials.gov Registration Number: NCT05272475.

Effect of chamomile intake on blood coagulation tests in healthy volunteers: a randomized, placebo-controlled, crossover trial.

BACKGROUND: Chamomile is consumed worldwide for enjoyment and its potentially desirable properties. Widespread patient resource websites, however, discourage preoperative chamomile intake, lest bleeding could worsen. This precaution, though, stems largely from indirect evidence in one case report. To evaluate if chamomile ingestion impacts coagulation assays via coumarin-like substances, we designed a randomized, placebo-controlled, crossover study. MATERIALS AND METHODS: Healthy volunteers were randomized to three interventions in a cross-over-design spanning 5 weeks per subject. Interventions included 7-day consumption of chamomile tea (3 tea bags × 3 times daily = 9 tea bags daily), a chamomile extract capsule (3 times daily), or a placebo capsule (3 times daily). A 7-day washout period elapsed between intervention periods. The primary outcome was the change in prothrombin time (PT) before vs. after each intervention. Secondary outcomes included changes in the international normalized ratio (INR), activated partial thromboplastin time (aPTT), thrombin time (TT), reptilase time (RT), and fibrinogen (FG) surrounding each intervention. RESULTS: All 12 enrolled subjects were randomized and completed the study. The primary outcome of PT change (mean ± SD) was similar across interventions (chamomile tea = - 0.2 ± 0.4 s, extract capsule = - 0.2 ± 0.4 s, and placebo capsule = 0.1 ± 0.5 s; p = 0.34). INR change was 0 s (p = 0.07) for each intervention. The aPTT, TT, RT, and FG, did not change significantly across interventions (p = 0.8, p = 0.08, p = 0.8, and p = 0.2 respectively). CONCLUSIONS: Chamomile intake by tea or capsule does not prolong PT. These findings challenge the notion to avoid perioperative chamomile intake in patients not taking warfarin. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05006378; Principal Investigator: Jonathon Schwartz, M.D.; Registered August 16, 2021.

Ability of the integrated pulmonary index to predict impending respiratory events in the early postoperative period.

BACKGROUND: In the early postoperative period, respiratory compromise is a significant problem. Standard-of-care monitoring includes respiratory rate (RR) and pulse oximetry, which are helpful; however, low SpO2 is often a late sign during decompensation. The FDA-approved Capnostream-20p monitor records four variables (SpO2, RR, End-tidal CO2, heart rate), which are combined by fuzzy logic into a single, unit-less value (range 1-10) called the integrated pulmonary index (IPI). No published studies have assessed the performance of a low IPI to predict impending respiratory events. METHODS: In this investigator-initiated study, adult patients undergoing general anesthesia were monitored with the Capnostream-20p monitor for up to 2 h during their recovery room stay. The study coordinator, who along with clinicians, was blinded to IPI values, recorded the time of any respiratory event, defined a priori as any one of eight respiratory-related interventions/conditions. The primary sensitivity endpoint (early detection success) was defined as at least 80% of events predicted by at least 2 consecutive low IPI (≤ 7) values within 2-15 min before an event occurred. Late detection was defined as low IPI values occurring with 2 min prior to or 2 min after the event occurred. DISCUSSION: Of 358 patients, ≥ 1 respiratory event occurred in 183 (51.1%) patients. Of 802 total events, 606 were detected early (within 2-15 min prior to the event), and 653 were detected either early or late. Therefore, the sensitivity for early detection was 75.6% (95% confidence interval [CI]: 72.6-78.5%), which differed significantly from the 80% sensitivity goal by 4.4% (p = 0.0016). Sensitivity for total success (early or late) was 81.4% (95% CI: 78.7-84.1%), which was significantly different from the 90% on time sensitivity goal by 8.6% (p < 0.0001). CONCLUSIONS: A low IPI was 75.6% sensitive for early detection (within 2-15 min) prior to respiratory events but did not achieve our preset threshold of 80% for success.