Effectiveness and safety of cuff inflation technique over conventional method of Magill forceps for Nasotracheal intubation under direct laryngoscopy: Randomized controlled trial

The aim of the study is to compare the effectiveness and safety of cuff inflation technique over conventional method of Magill forceps for Nasotracheal intubation NTI under direct laryngoscopy.After taking permission from institutional ethical committee, patients of 18-60 years of either sex of ASA grade I and ll were divided into groups of 40 each. In group C, cuff inflation technique and in group M, Magill forceps technique was used for navigating the endotracheal tube from oropharynx to glottic opening to achieve intubation. Parameters observed were time required for intubation, attempts of intubation, injury occurring to oropharyngeal structures during intubation and hemodynamic parameters. Cuff of endotracheal tube was assessed postoperatively for any leaksAnalysis of the data for the various parameters was done using paired t-test for intra-group comparison and student t-test for intergroup comparison and chi-square test was used for qualitative (non parametric) data.There was no significant difference in demographic parameters, time required for intubation, number of attempts for intubation and hemodynamic parameters, but trauma to oropharyngeal structures was more in group M (8/40) compared to group C (0/40). (p≤0.05) Trauma to cuff of endotracheal tube was seen in group M (1/40) while none in group C (0/40) which was statistically not significant (p≤0.05).Thus, Cuff inflation technique can be used as an effective alternative to Magill forceps for oropharyngeal navigation of endotracheal tube under direct laryngoscopy guided nasotracheal intubation in patients with normal airways.

Abstract MP71: Impact Of 30 Versus 60 Second Time Interval Between Automated Office Blood Pressure Measurements On Measured Blood Pressure

Background: Guidelines advocate for the use of automated office-based blood pressure (AOBP) measurement to improve accuracy of blood pressure (BP) measurement in the outpatient clinical setting. Current recommendations include a 5-minute period of quiet rest prior to obtaining 3 readings, each separated by 1-2 minutes. As a result, AOBP requires a minimum of 7 minutes of rest time in addition to proper patient positioning plus cuff inflation and deflation, adding nearly 10 minutes to an office visit. Reducing this by even 1 minute has broad implications for the widespread use of AOBP. Methods: Patients from a single hypertension center underwent a 3-day evaluation that included a 24-hour ambulatory BP monitor (ABPM) and one of two, non-randomized, unattended AOBP protocols. Half of patients underwent 3 BP measurements separated by 30 seconds and the other half underwent 3 BP measurements separated by 60 seconds. All measurements were compared to the average awake-time BP from ABPM as well as the first AOBP measurement. Results: Among 102 patients, the average awake-time BP was 128.6±13.6/76.5±12.5 mmHg for the 30-second protocol and 132.5±15.6/77.7±12.2 mmHg among those who underwent the 60-second protocol . Mean BP was lower with the 2nd and 3rd AOBP measurement by -0.5/-1.7 mmHg and -1.0/-2.3 mmHg for the 60-second protocol versus -0.8/-2.0 mmHg and -0.7/-2.7 mmHg for the 30-second protocol ( Figure ). Differences between AOBP measurements (1st, 2nd, or 3rd) and awake-time ABPM were nearly identical across protocols. Conclusion: A 30-second interval between AOBP measurements was as accurate and reliable as a 60-second interval.

Modulation of Pulse Propagation and Blood Flow via Cuff Inflation—New Distal Insights

In standard critical care practice, cuff sphygmomanometry is widely used for intermittent blood pressure (BP) measurements. However, cuff devices offer ample possibility of modulating blood flow and pulse propagation along the artery. We explore underutilized arrangements of sensors involving cuff devices which could be of use in critical care to reveal additional information on compensatory mechanisms. In our previous work, we analyzed the response of the vasculature to occlusion perturbations by means of observations obtained non-invasively. In this study, our aim is to (1) acquire additional insights by means of invasive measurements and (2) based on these insights, further develop cuff-based measurement strategies. Invasive BP experimental data is collected downstream from the cuff in two patients monitored in the OR. It is found that highly dynamic processes occur in the distal arm during cuff inflation. Mean arterial pressure increases in the distal artery by 20 mmHg, leading to a decrease in pulse transit time by 20 ms. Previous characterizations neglected such distal vasculature effects. A model is developed to reproduce the observed behaviors and to provide a possible explanation of the factors that influence the distal arm mechanisms. We apply the new findings to further develop measurement strategies aimed at acquiring information on pulse arrival time vs. BP calibration, artery compliance, peripheral resistance, artery-vein interaction.

Assessing the accuracy of ultrasound measurements of tracheal diameter: an in vitro experimental study

Background Recent studies indicate that ultrasound can detect changes in tracheal diameter during endotracheal tube (ETT) cuff inflation. We sought to assess the accuracy of ultrasound measurement of tracheal diameter, and to determine the relationship between tracheal wall pressure (TWP), cuff inflation volume (CIV), and the degree of tracheal deformation. Methods Our study comprised two parts: the first included 45 porcine tracheas, the second 41 porcine tracheas. Each trachea was intubated with a cuffed ETT, which was connected to an injector and the manometer via a three-way tap. The cuff was inflated and the cuff pressure recorded before and after intubation. The tracheal diameter was measured using ultrasound. This included three separate measurements: outer transverse diameter (OTD), internal transverse diameter (ITD), and anterior tracheal wall thicknesses (ATWT). A precision electronic Vernier caliper was also used to measure tracheal diameter. We calculated TWP and the percentage change of tracheal diameter. The Bland–Altman method, linear regression, and locally weighted regression (LOESS) were used to analyze the data. Results There were strong correlation and agreement for OTD (r = 0.97, P < 0.001) and ITD (r = 0.90, P < 0.001) as measured by ultrasound and by precision electronic Vernier caliper, but a poor correlation for ATWT (r = 0.58, P < 0.001). There was a strong correlation between the percentage change of OTD (OTD%, r = 0.75, P < 0.001) and CIV, the percentage change of ITD (ITD%, r = 0.77, P < 0.001) and CIV, TWP (r = 0.75, P < 0.001) and CIV. And a strong correlation was also found between TWP and OTD% (r = 0.84, P < 0.001), TWP and ITD% (r = 0.84, P < 0.001). Conclusions Use of ultrasound to measure OTD and ITD is accurate, but is less accurate for ATWT. There is a close correlation between OTD%, ITD%, CIV and TWP.