Vital sign monitoring with continuous pulse oximetry and wireless clinical notification after surgery (the VIGILANCE pilot study)—a randomized controlled pilot trial

Abstract Background Respiratory depression is a serious perioperative complication associated with morbidity and mortality. Recently, technology has become available to wirelessly monitor patients on regular surgical wards with continuous pulse oximetry and wireless clinician notification with alarms. When a patient’s SpO2 falls below a set threshold, the clinician is notified via a pager and may intervene earlier to prevent further clinical deterioration. To date, the technology has not been evaluated with a randomized controlled trial (RCT). Methods We designed a parallel-group unblinded pilot RCT of a wireless monitoring system on two surgical wards in an academic teaching hospital. Postsurgical patients with an anticipated length of stay of at least 1 day were included and randomized to standard care or standard care plus wireless respiratory monitoring for up to a 72-h period. The primary outcomes were feasibility outcomes: average patients recruited per week and tolerability of the system by patients. Secondary outcomes included (1) respiratory events (naloxone administration for respiratory depression, ICU transfers, and cardiac arrest team activation) and (2) system alarm types and details. The analysis of the outcomes was based on descriptive statistics and estimates reported using point (95% confidence intervals). Criteria for success of feasibility were recruitment of an average of 15 patients/week and 90% of the patients tolerating the system. Results The pilot trial enrolled 250 of the 335 patients screened for eligibility, with 126 and 124 patients entering the standard monitoring and wireless groups, respectively. Baseline demographics were similar between groups, except for slightly more women in the wireless group. Average patient recruitment per week was 14 95% CI [12, 16] patients. The wireless monitoring was quite tolerable with 86.6% (95% CI 78.2–92.7%) of patients completing the full course, and there were no other adverse events directly attributable to the monitoring. With regard to secondary outcomes, the respiratory event rate was low with only 1 event in the wireless group and none in the control group. The average number of alarms per week was 4.0 (95% CI, 1.6–6.4). Conclusions This pilot study demonstrated adequate patient recruitment and high tolerability of the wireless monitoring system. A full RCT that is powered to detect patient important outcomes such as respiratory depression is now underway. Trial registration ClinicalTrials.gov, Registration number NCT02907255, registered 7 September 2016—retrospectively registered

Postoperative B-type natriuretic peptide for prediction of major cardiac events in patients undergoing noncardiac surgery:systematic review and individual patient meta-analysis

BACKGROUND: It is unclear whether postoperative B-type natriuretic peptides (i.e., BNP and N-terminal proBNP) can predict cardiovascular complications in noncardiac surgery. METHODS: The authors undertook a systematic review and individual patient data meta-analysis to determine whether postoperative BNPs predict postoperative cardiovascular complications at 30 and 180 days or more. RESULTS: The authors identified 18 eligible studies (n = 2,051). For the primary outcome of 30-day mortality or nonfatal myocardial infarction, BNP of 245 pg/ml had an area under the curve of 0.71 (95% CI, 0.64-0.78), and N-terminal proBNP of 718 pg/ml had an area under the curve of 0.80 (95% CI, 0.77-0.84). These thresholds independently predicted 30-day mortality or nonfatal myocardial infarction (adjusted odds ratio [AOR] 4.5; 95% CI, 2.74-7.4; P <0.001), mortality (AOR, 4.2; 95% CI, 2.29-7.69; P <0.001), cardiac mortality (AOR, 9.4; 95% CI, 0.32-254.34; P <0.001), and cardiac failure (AOR, 18.5; 95% CI, 4.55-75.29; P <0.001). For greater than or equal to 180-day outcomes, natriuretic peptides independently predicted mortality or nonfatal myocardial infarction (AOR, 3.3; 95% CI, 2.58-4.3; P <0.001), mortality (AOR, 2.2; 95% CI, 1.67-86; P <0.001), cardiac mortality (AOR, 2.1; 95% CI, 0.05-1,385.17; P <0.001), and cardiac failure (AOR, 3.5; 95% CI, 1.0-9.34; P = 0.022). Patients with BNP values of 0-250, greater than 250-400, and greater than 400 pg/ml suffered the primary outcome at a rate of 6.6, 15.7, and 29.5%, respectively. Patients with N-terminal proBNP values of 0-300, greater than 300-900, and greater than 900 pg/ml suffered the primary outcome at a rate of 1.8, 8.7, and 27%, respectively. CONCLUSIONS: Increased postoperative BNPs are independently associated with adverse cardiac events after noncardiac surgery

The prognostic value of pre-operative and post-operative B-type natriuretic peptides in patients undergoing noncardiac surgery:B-type natriuretic peptide and N-terminal fragment of pro-B-type natriuretic peptide: a systematic review and individual patient data meta-analysis

OBJECTIVES: The objective of this study was to determine whether measuring post-operative B-type natriuretic peptides (NPs) (i.e., B-type natriuretic peptide [BNP] and N-terminal fragment of proBNP [NT-proBNP]) enhances risk stratification in adult patients undergoing noncardiac surgery, in whom a pre-operative NP has been measured. BACKGROUND: Pre-operative NP concentrations are powerful independent predictors of perioperative cardiovascular complications, but recent studies have reported that elevated post-operative NP concentrations are independently associated with these complications. It is not clear whether there is value in measuring post-operative NP when a pre-operative measurement has been done. METHODS: We conducted a systematic review and individual patient data meta-analysis to determine whether the addition of post-operative NP levels enhanced the prediction of the composite of death and nonfatal myocardial infarction at 30 and ≥180 days after surgery. RESULTS: Eighteen eligible studies provided individual patient data (n = 2,179). Adding post-operative NP to a risk prediction model containing pre-operative NP improved model fit and risk classification at both 30 days (corrected quasi-likelihood under the independence model criterion: 1,280 to 1,204; net reclassification index: 20%; p < 0.001) and ≥180 days (corrected quasi-likelihood under the independence model criterion: 1,320 to 1,300; net reclassification index: 11%; p = 0.003). Elevated post-operative NP was the strongest independent predictor of the primary outcome at 30 days (odds ratio: 3.7; 95% confidence interval: 2.2 to 6.2; p < 0.001) and ≥180 days (odds ratio: 2.2; 95% confidence interval: 1.9 to 2.7; p < 0.001) after surgery. CONCLUSIONS: Additional post-operative NP measurement enhanced risk stratification for the composite outcomes of death or nonfatal myocardial infarction at 30 days and ≥180 days after noncardiac surgery compared with a pre-operative NP measurement alone