Postoperative respiratory state assessment using the Integrated Pulmonary Index (IPI) and resultant nurse interventions in the post-anesthesia care unit: a randomized controlled trial

Continuous Capnography for Early Detection of Respiratory Compromise During Gastroenterological Procedural Sedation and Analgesia

Gastroenterology nurses working across a variety of clinical settings are responsible for periprocedural monitoring during moderate to deep procedural sedation and analgesia (PSA) to identify signs of respiratory compromise and intervene to prevent cardiorespiratory events. Pulse oximetry is the standard of care for respiratory monitoring, but it may delay or fail to detect abnormal ventilation during PSA. Continuous capnography, which measures end-tidal CO2 as a marker of alveolar ventilation, has been endorsed by a number of clinical guidelines. Large clinical trials have demonstrated that the addition of continuous capnography to pulse oximetry during PSA for various gastroenterological procedures reduces the incidence of hypoxemia, severe hypoxemia, and apnea. Studies have shown that the cost of adding continuous capnography is offset by the reduction in adverse events and hospital length of stay. In the postanesthesia care unit, continuous capnography is being evaluated for monitoring opioid-induced respiratory depression and to guide artificial airway removal. Studies are also examining the utility of continuous capnography to predict the risk of opioid-induced respiratory depression among patients receiving opioids for primary analgesia. Continuous capnography monitoring has become an essential tool to detect early signs of respiratory compromise in patients receiving PSA during gastroenterological procedures. When combined with pulse oximetry, it can help reduce cardiorespiratory adverse events, improve patient outcomes and safety, and reduce health care costs.

Predictive value of diaphragmatic thickness fraction and integrated pulmonary index on extubation outcome in patients with severe acute pancreatitis

OBJECTIVE

This study was performed to explore the predictive value of the diaphragmatic thickness fraction (DTF) combined with the integrated pulmonary index (IPI) for the extubation outcome in patients with severe acute pancreatitis (SAP).

METHODS

This prospective study involved 93 patients diagnosed with SAP and treated with mechanical ventilation in our hospital from October 2020 to September 2023. The patients were divided into a successful extubation group (61 patients) and an extubation failure group (32 patients) based on the extubation outcomes. The predictive value of the DTF, IPI, and their combination for extubation failure was analyzed.

RESULTS

The DTF and IPI were independent risk factors for extubation failure in patients with SAP undergoing mechanical ventilation. In addition, the combination of the DTF and IPI showed predictive value for extubation failure in these patients.

CONCLUSION

The DTF and IPI hold predictive value for extubation failure in patients with SAP undergoing mechanical ventilation, and their combined use may improve the predictive efficiency.

Outcomes in patients receiving continuous monitoring of vital signs on general wards: A systematic review and meta-analysis of randomised controlled trials

Objective

The timely identification of deterioration on general wards is crucial to patient care with each hour of delay independently associated with increased risk of death. The introduction of continuous monitoring of patient vital signs on general wards, currently not standard care, may improve patient outcomes. Our aim was to investigate whether patients on general wards receiving continuous vital signs monitoring have better outcomes than patients receiving usual care.

Methods

Meta-analysis of randomised controlled trials comparing non-critical care patients receiving continuous monitoring of vital signs to usual care. We searched Medline, Embase, and Web of Science, and assessed risk of bias with version 2 of the Cochrane risk-of-bias tool for randomised trials. In addition to measures related to the early detection of deterioration, we planned to present all patient outcomes reported by the clinical trials included.

Results

We included seven trials involving 1284 participants. There were no statistically significant differences in the four outcomes pooled. Comparing continuously monitored to normal care, the pooled odds for hospital mortality, major event/complication, and HDU/ICU admission was 0.95 (95% CI 0.59-1.53, p = 0.84; 660 participants, 3 studies), 0.71 (95% CI 0.38-1.31, p = 0.27; 948 participants, 4 studies) and 0.82 (95% CI 0.25-2.67, p = 0.74; 655 participants, 4 studies), respectively. The mean difference for length of stay was 2.12 days lower (95% CI -5.56 to 1.32, p = 0.23; 1034 participants, 6 studies).

Conclusion

We found no significant improvements in outcomes for patients continuously monitored compared to usual care. Further research is needed to understand what modalities of continuous monitoring may influence outcomes and investigate the implications of a telepresence service and multi-parameter scoring system.

Registration

PROSPERO CRD42023458656.

The Use of End-Tidal CO2 and Integrated Pulmonary Index to Predict Postspinal Hypotension in Cesarean Section

Early diagnosis and treatment of postspinal hypotension (PSH) in obstetric anaesthesia reduces the risk of maternofetal complications. In this study, the effect of EtCO2 and the integrated pulmonary index (IPI) in predicting PSH was investigated. Patients scheduled for cesarean section under spinal anaesthesia were included. The Capnostream 35 respiratory monitor (Medtronic, Inc., Dublin, Ireland) was used for EtCO2 and IPI. PSH developed in 52 (63.4%) of the 82 patients. EtCO2 and IPI values decreased significantly compared with baseline values in patients who developed PSH. There were statistically significant differences in EtCO2 (p = 0.001) and the IPI change (p = 0.045) in patients who developed PSH compared with those who did not. It was found that the EtCO2 difference had an independent effect on predicting PSH (p < 0.05), whereas the IPI difference did not (p > 0.05). One unit decrease in EtCO2 from the baseline increased the risk of PSH by 3.3 times. ROC curve analysis showed that the magnitude of change in EtCO2 was diagnostic for predicting PSH (AUC: 0.90 (0.83-0.97; p < 0.001)). IPI showed no predictive value for postspinal hypotension in cesarean section. However, EtCO2 monitoring, which is non-invasive and real-time monitoring, can be used to predict postspinal hypotension.

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.

Identification and Prevention of Extubation Failure by Using an Automated Continuous Monitoring Alert Versus Standard Care

BACKGROUND

Postextubation monitoring helps identify patients at risk of developing respiratory failure. This study aimed to evaluate the effect of our standard respiratory therapist (RT) assessment tool versus an automated continuous monitoring alert to initiate postextubation RT-driven care on the re-intubation rate.

METHODS

This was a single-center randomized clinical trial from March 2020 to September 2021 of adult subjects who received mechanical ventilation for > 24 h and underwent planned extubation in the ICU. The subjects were assigned to the standard RT assessment tool or an automated monitoring alert to identify the need for postextubation RT-driven care. The primary outcome was the need for re-intubation due to respiratory failure within 72 h. Secondary outcomes included re-intubation within 7 d, ICU and hospital lengths of stay, hospital mortality, ICU cost, and RT time associated with patient assessment and therapy provision.

RESULTS

Of 234 randomized subjects, 32 were excluded from the primary analysis due to disruption in RT-driven care during the surge of patients with COVID-19, and 1 subject was excluded due to delay in the automated monitoring initiation. Analysis of the primary outcome included 85 subjects assigned to the standard RT assessment group and 116 assigned to the automated monitoring alert group to initiate RT-driven care. There was no significant difference between the study groups in re-intubation rate, median length of stay, mortality, or ICU costs. The RT time associated with patient assessment (P < .001) and therapy provided (P = .031) were significantly lower in the automated continuous monitoring alert group.

CONCLUSIONS

In subjects who received mechanical ventilation for > 24 h, there were no significant outcome or cost differences between our standard RT assessment tool or an automated monitoring alert to initiate postextubation RT-driven care. Using an automated continuous monitoring alert to initiate RT-driven care saved RT time. (ClinicalTrials.gov registration NCT04231890).

Respiratory monitoring of nonintubated patients in nonoperating room settings: old and new technologies

PURPOSE OF REVIEW

Postoperative mortality in the 30 days after surgery remains disturbingly high. Inadequate, intermittent and incomplete monitoring of vital signs in the nonoperating room environment is common practice. The rise of nonoperating room anaesthesia and sedation outside the operating room has highlighted the need to develop new and robust methods of portable continuous respiratory monitoring. This review provides a summary of old and new technologies in this environment.

RECENT FINDINGS

Technical advances have made possible the utilization of established monitoring to extrapolate respiratory rate, the increased availability and user friendliness of side stream capnography and the advent of other innovative systems. The use of aggregate signals wherein different modalities compensate for individual shortcomings seem to provide a reliable and artefact-free system.

SUMMARY

Respiratory monitoring is required in several situations and patient categories outside the operating room. The chosen modality must be able to detect respiratory compromise in a timely and accurate manner. Combing several modalities in a nonobtrusive, nontethered system and having an integrated output seems to give a reliable and responsive signal.