Knowledge and practice of tracheal tube cuff pressure monitoring: a multicenter survey of anaesthesia and critical care providers in a developing country

Background Tracheal tubes are routinely used during anaesthesia and in the intensive care unit. Subjective monitoring of cuff pressures have been reported to produce consistently inappropriate cuffs pressures, with attendant morbidity. But this practice of unsafe care remains widespread. With the proliferation of intensive care units in Nigeria and increasing access to surgery, morbidity relating to improper tracheal cuff pressure may assume a greater toll. We aimed to evaluate current knowledge and practice of tracheal cuff pressure monitoring among anaesthesia and critical care providers in Nigeria. Methods This was a multicenter cross-sectional study conducted from March 18 to April 30, 2021. The first part (A) was conducted at 4 tertiary referral hospitals in Nigeria by means of a self-administered questionnaire on the various cadre of anaesthesia and critical care providers. The second part (B) was a nation-wide telephone survey of anaesthesia faculty fellows affiliated to 13 tertiary hospitals in Nigeria, selected by stratified random sampling. Results Only 3.1% (6/196) of the care providers admitted having ever used a tracheal cuff manometer, while 31.1% knew the recommended tracheal cuff pressure. The nationwide telephone survey of anaesthesia faculty fellows revealed that tracheal cuff manometer is neither available, nor has it ever been used in any of the 13 tertiary hospitals surveyed. The ‘Pilot balloon palpation method’ and ‘fixed volume of air from a syringe’ were the most commonly utilized method of cuff pressure estimation by the care providers, at 64.3% and 28.1% respectively in part A survey (84.6% and 15.4% respectively, in the part B survey). Conclusion The use of tracheal cuff manometer is very limited among the care providers surveyed in this study. Knowledge regarding tracheal cuff management among the providers is adjudged to be fair, despite the poor practice and unsafe care.

Vasodilatation Measurement Using Finger Vascular Images by Near-Infrared Light and Comparison with RH-PAT

Examination of vascular endothelial function can help infer atherosclerosis progression. This study investigated whether vascular visualization by near-infrared (NIR) light can detect vasodilatation after cuff pressure release of the upper arm and what the correlation is between the brightness decrease ratio (R1) corresponding to vasodilation and the reactive hyperemia index (RHI). We obtained finger vascular images of 53 male subjects by photographing NIR light (wavelength 850 nm) transmitted through the middle phalanx of the middle finger with a charge-coupled device camera. The upper arm was compressed for 10 min using a cuff (200 mmHg), and vascular images before and after cuff compression release were obtained. We analyzed the finger vascular images by NIR light and digital pulse volume using endothelial peripheral arterial tonometry (Endo-PAT). We also calculated the average brightness of each vascular image. Using only the data of the ischemic finger, R1 was defined using the average brightness just before cuff release and the minimum average brightness after cuff release. The brightness of vascular images of the ischemic finger decreased after cuff release probably because of vasodilation. We found significant correlation between R1 and the RHI (r = 0.52; P < 0.001). R1 in the lowest RHI quartile was significantly smaller compared to the highest and second-highest RHI quartiles (P < 0.05). Vascular visualization by NIR light can detect vasodilation after cuff release. This is significantly correlated with the RHI on Endo-PAT.

Intraoperative Evaluation of Effects of Different Gas Mixtures (Oxygen 100%, O2 50%:N2O 50%, Air on Cuff Pressure of PLMA (Proseal LMA)

Introduction:- we study the intra operative evaluation of different gas mixture(oxygen 100%, O2 50%:N2O 50%, AIR on cuff pressure of PLMA. Aims and Objectives:- To study intracuff pressure changes and the change in final volume of gas mixture during inflation and deflation during intraoperative period and postoperative complications. Material and Methods:- This double blind, prospective Study was conducted in Department of Anaesthesiology, Maharishi Markandeshwar Institute of Medical Sciences and Research, Mullana, Ambala following approval from institutional ethical committee and written informed patient consent. The sample size of 120 patient aged 18 to 60 years, belonging to ASA physical status 1 and 2 undergoing surgery in general anesthesia with PLMA as airway device divided into three group on the basis of PMLA cuff gas mixture:-Group O - oxygen 100%, Group ON - Nitrous 50%: Oxygen 50%, Group A – Air. Results and Conclusion:- Combination of N2O and O2 resulted in decreased intracuff pressure and air lead to a slight increase in intracuff pressure with O2 providing relatively stable cuff pressures. Keywords: PLMA,100% Oxygen, Air, Oxygen 50% N2O 50%, Air.

Evaluation of microbial contamination on cuff syringe, cuff pressure gauge, and their surroundings in the operating room

Background Some institutions reuse cuff syringes and do not periodically sterilize cuff pressure gauges. Pathogenic bacterial contamination of such equipment may increase the probability of pathogen transmission to patients during anesthetic procedures. Therefore, microbial contamination on cuff syringes, cuff pressure gauges, and their surroundings was assessed in the operating rooms of a university-affiliated tertiary care hospital in Japan. Methods This study was conducted between April and May 2019 in 14 operating suites at a hospital. The following sites in each operating suite were sampled: cuff syringe (inner/outer components), outer components of cuff pressure gauge, cuff syringe and cuff pressure gauge storage drawers, and computer mice. The swabs were directly streaked onto agar plates and incubated. Then, the bacterial species were identified using mass spectrometry. Results The highest bacterial isolation was observed in computer mice, followed by the outside of cuff pressure gauges and the drawers of cuff pressure gauges (92.9, 78.6, and 64.3%, respectively). Most of the identified bacteria belonged to the Bacillus species, with colonization rates of 85.7, 57.1, and 57.1% on computer mice, cuff pressure gauges, and cuff pressure gauge storage drawers, respectively. Coagulase-negative Staphylococcus was found in 35.7% of the specimens and was more prevalent on computer mice (71.4%), followed by on cuff pressure gauges (64.3%). Conclusion Anesthesiologists should be aware of the possible pathogen contamination risk from cuff syringes, cuff pressure gauges, or associated equipment and take appropriate infection control measures to minimize the risk of pathogenic transmission.

Deep learning-based robust automatic non-invasive measurement of blood pressure using Korotkoff sounds

This paper proposes a method that automatically measures non-invasive blood pressure (BP) based on an auscultatory approach using Korotkoff sounds (K-sounds). There have been methods utilizing K-sounds that were more accurate in general than those using cuff pressure signals only under well-controlled environments, but most were vulnerable to the measurement conditions and to external noise because blood pressure is simply determined based on threshold values in the sound signal. The proposed method enables robust and precise BP measurements by evaluating the probability that each sound pulse is an audible K-sound based on a deep learning using a convolutional neural network (CNN). Instead of classifying sound pulses into two categories, audible K-sounds and others, the proposed CNN model outputs probability values. These values in a Korotkoff cycle are arranged in time order, and the blood pressure is determined. The proposed method was tested with a dataset acquired in practice that occasionally contains considerable noise, which can degrade the performance of the threshold-based methods. The results demonstrate that the proposed method outperforms a previously reported CNN-based classification method using K-sounds. With larger amounts of various types of data, the proposed method can potentially achieve more precise and robust results.

Pepsin A in Tracheal Secretions From Patients Receiving Mechanical Ventilation

Background In patients in the intensive care unit (ICU) receiving mechanical ventilation, aspiration of gastric contents may lead to ventilator-associated events and other adverse outcomes. Pepsin in pulmonary secretions is a biomarker of microaspiration of gastric contents. Objectives To evaluate the association between tracheal pepsin A and clinical outcomes related to ventilator use. Methods A subset of 297 patients from a larger clinical trial on aspiration of oral secretions in adults receiving mechanical ventilation consented to have pepsin A measured in their tracheal aspirate samples. A concentration ≥6.25 ng/mL indicated a positive result. Abundant microaspiration was defined as pepsin A in ≥30% of samples. Statistical analyses included analysis of variance, analysis of covariance, and χ2 tests. Results Most patients were White men, mean age 59.7 (SD, 18.8) years. Microaspiration was found in 43.8% of patients (n = 130), with abundant microaspiration detected in 17.5% (n = 52). After acuity was controlled for, patients with tracheal pepsin A had a longer mechanical ventilation duration (155 vs 104 hours, P &lt; .001) and ICU stay (9.9 vs 8.2 days, P = .04), but not a longer hospital stay. Conclusions Microaspiration of gastric contents occurred in nearly half of patients and was associated with a longer duration of mechanical ventilation and a longer stay in the ICU. Additional preventative interventions beyond backrest elevation, oropharyngeal suctioning, and management of endotracheal tube cuff pressure may be needed. Also, the timing of pepsin measurements to capture all microaspiration events requires additional exploration.

Tracheal lesion during shoulder surgery: a case report and systemic review of the literature

Pneumomediastinum (PNM) and pneumothorax (PNX) are documented complications of arthroscopic shoulder surgery (ATS). Plexus anesthetic block and tracheal lesions during endotracheal intubation are hypothesized to be the underlying risk factors; however, the actual evidence supporting this hypothesis is scarce.A case of bilateral laterocervical emphysema, subcutaneous edema, and signs of PNM after ATS performed under general anesthesia and supra-scapular nerve block is presented. An up-to-date systematic review of PNM/PNX during orthopedic surgery was performed, involving six databases: PubMed (1996–present), Embase (1974–present), Scopus (2004–present), SpringerLink (1950–present), Ovid Emcare (1995–present), and Google Scholar (2004–present).Twenty-five case studies met the eligibility criteria. In 24 cases, the patient underwent general anesthesia and orotracheal intubation; in 9 of these, a plexus anesthetic block was also performed. One case involved ATS under plexus anesthetic block only. In 10 cases, the diagnostic finding was PNM. In 5 cases, the diagnostic finding was associated with PNX. PNX was detected in 17 cases. In 2 cases, SE was found in the absence of any evidence of either PNM or PNX. A tracheal lesion was identified in 3 cases.Endotracheal intubation and loco-regional anesthesia are not the only predisposing risk factors at play in the pathogenesis of PNM/PNX. Rather, multi-factorial pathogenesis seems more probable, necessitating that specific attention is paid during ATS to the change in patient position on the operating bed, to any slipping of the endotracheal tube, to patient monitoring whilst under the drapes, and to the cuff pressure. PROSPERO registration number: CRD42021260370.

Retention of knowledge on blood pressure measurement among medical students within preparation for primary accreditation

Aim. To assess the retained knowledge of sixth year medical students on noninvasive blood pressure (BP) measurement.Material and methods. The study included 148 6th year medical students. According to the curriculum, in the fall semester, students studied the procedure of BP measurement according to checklists developed based on ROSOMED. In the spring semester, as part of the preparation course for accreditation, the retained knowledge of students was assessed. A completed skill was assessed at 1 point, not completed — 0 points. Thus, each student can score a maximum of 50 points. The teacher assessed the manipulations during their performing by filling in the checklist items for each student.Results. None of the students completed the full range of manipulations. The number of completed skills ranged from 15 (30%) to 49 (98%) and averaged 33 points on the checklist (66%). In addition, 74% of students (n=109) completed more than half of the required skills. Almost the only item completed by all students (99%, n=146) was a greeting, which was comparable with self-presentation (92%, n=136) and identification of a patient’s personal data (surname and first names) (80%, n=118). The rest of checklist items was performed in the range from 39% (n=57) for “remeasurement of BP on the other hand” to 87% (n=129) for “finding a radial pulse”. Thus, the average fulfillment rate was 67% (n=99). There were following most common mistakes in BP measurement: 39% of students did not measure a patient’s upper arm diameter and did not select the cuff size; every second student (51%) placed the phonendoscope diaphragm under the cuff; 40% of students reduced the cuff pressure with inadequate rate.Conclusion. The retention of knowledge on measuring BP within six months after a detailed analysis and passing a test remains insufficient, but comparable with foreign studies. The data obtained indicate the need for additional trainings both using simulators and in conditions closer to real ones, including with simulated patients.

Intraoperative Measurement of Endotracheal Tube Cuff Pressure and Its Change During Surgery in Correlation With Recurrent Laryngeal Nerve Palsies, Hoarseness, and Dysphagia After Anterior Cervical Discectomy and Fusion: A Prospective Randomized Controlled Trial

Study Design Prospective randomized controlled trial. Objectives Adjustment of endotracheal tube cuff pressure (ETCP) in anterior cervical discectomy and fusion (ACDF) may influence the incidence of complications such as recurrent laryngeal nerve palsy (RLNP), hoarseness, and dysphagia. Methods The prospective randomized controlled trial was designed to investigate the influence of ETCP on the incidence of postoperative complications. All eligible patients underwent vocal cord examination before and after ACDF and were randomized into a control group (CG) and intervention group (IG). Endotracheal tube cuff pressure was passively monitored in CG, and in IG, it was maintained at 20 mmHg. Outcomes were evaluated during hospitalization and during follow-up. Results A total of 98 patients were randomized, each group consisted of 49 patients. Statistical analysis showed that gender and age did not influence the incidence of complications. In CG, duration of retractor placement and extent of approach significantly impacted the occurrence of complications. The incidence of postoperative RLNP was 8.2% in IG and 12.2% in CG, hoarseness and dysphonia were present in 18.4% in IG and in 37.5% in CG, and dysphagia in 20.8% in IG and in 22.5% in CG. Hoarseness was significantly present more in CG ( P = .018). Only one patient from CG presented with RLNP after 1 year, the remaining nine patients spontaneously recovered. Conclusions Unregulated ETCP can lead to a significantly higher incidence of hoarseness; however, its improvement rate is 100%. The early postoperative complication rate was higher in CG, and after one year, 1 patient had RLNP and 1 patient had dysphagia.