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.

A Survey of Dentist Anesthesiologists on Preoperative Intramuscular Sedation

OBJECTIVE

The induction of general anesthesia for children and patients with special needs frequently requires preinduction sedation, especially when anxiety and agitation lead to violent or combative behavior. In these situations, preoperative intramuscular (IM) sedation may facilitate patient transfer, intravenous cannulation, and/or mask induction. This survey aimed to capture data regarding the current preoperative IM sedation practices of dentist anesthesiologists.

METHODS

An electronic survey was distributed in 2020 to all members of the American Society of Dentist Anesthesiologists regarding the administration of preoperative IM sedation. It included questions about the demographics of respondents and their patients who require IM sedation, the most common drug regimens used, decision-making criteria regarding ketamine dosing, the intended level of sedation, sequence of anesthetic management following IM sedation, and observed outcomes.

RESULTS

A total of 193 responses (43%) were received; of those, 162 reported using preoperative IM sedation. Ketamine was included in 98.7% of reported IM drug regimens. The most common IM sedation regimen was combined ketamine and midazolam (median 2.5 mg/kg and 0.1 mg/kg, respectively). Of the respondents who use preoperative IM sedation, 87% reported using the same drug regimen in at least 80% of cases.

CONCLUSION

The most frequently reported drug regimen used by dentist anesthesiologists in North America for preoperative IM sedation was a combination of ketamine and midazolam.

Retrospective Comparison of Intramuscular Admixtures of Ketamine and Dexmedetomidine Versus Ketamine and Midazolam for Preoperative Sedation

Precooperative children and patients with intellectual disabilities often require intramuscular (IM) sedation prior to the induction of general anesthesia (GA). Ketamine is an effective preinduction sedative but can produce significant adverse side effects. Dexmedetomidine, a sedative with sympatholytic and analgesic properties, may provide advantages when used in combination with ketamine. This retrospective study evaluated the efficacy and safety of IM ketamine with dexmedetomidine for preoperative sedation. We conducted a chart review of all patients (n = 105) treated for dental rehabilitation who received either IM ketamine and dexmedetomidine (study group, n = 74) or IM ketamine and midazolam (control group, n = 31) prior to induction of GA. No significant difference (p = .14) was observed in the time interval from IM administration to operating room entry (median [interquartile range]) between the study and control groups (5 [4-8] vs 5 [2-7] minutes). Patients who received IM dexmedetomidine exhibited significantly lower mean arterial pressures throughout the induction (p = .004) and had lower heart rates (p = .01) throughout the intraoperative period compared with patients who did not receive dexmedetomidine. The combination of dexmedetomidine and ketamine may provide effective and safe IM sedation prior to the induction of GA.