Julie Rice

Cuffed endotracheal tubes in infants and children: Should we routinely measure the cuff pressure?

OBJECTIVE Over the past 5 years, there has been a change in the clinical practice of pediatric anesthesiology with a transition to the use of cuffed instead of uncuffed endotracheal tubes in infants and children. However, there are few studies evaluating the current practices of inflation of these cuffs and the intracuff pressures. METHOD There was no change dictated in clinical practice for these patients. During the first 30 min of the case, the pressure in the cuff was measured using a hand held manometer. Additional data collected included the patients demographic data (age, weight, and gender), the size of the ETT, whether nitrous oxide was in use, whether the patient was breathing spontaneously or undergoing positive pressure ventilation, and the type of anesthesia provider (resident, fellow, CRNA or SRNA). RESULTS The cohort for the study included 200 patients ranging in age from 1 month to 17 years and in weight from 3.5 to 99.1 kg. The average cuff pressure was 23 ± 22 cmH(2)O in the total cohort of 200 patients. The cuff pressure was ≥ 30 cmH(2)O in 47 of the 200 patients (23.5%). The average cuff pressure was significantly higher in patients who were 8 years of age or greater compared to younger patients. Additionally, there were significantly more patients with a cuff pressure ≥ 30 cmH(2)O in the ≥ 8 year old age group. Although no difference in the mean cuff pressure was noted when comparing staff anesthesia providers (pediatric anesthesiologist or CRNA) versus trainees (SRNA, anesthesiology resident, medical student or pediatric anesthesiology fellow), the incidence of significantly excessive cuff pressures (≥ 60 cmH(2)O) was higher in the trainee group versus the faculty group (12 of 99 versus 2 of 101, p<0.0001). CONCLUSIONS Using current clinical practice to inflate the cuff, a significant percentage of pediatric patients have an intracuff pressure greater than the generally recommended upper limit of 30 cmH(2)O.

Accuracy of Noninvasive and Continuous Hemoglobin Measurement by Pulse Co-Oximetry During Preoperative Phlebotomy

Background: In recent years, the continuous noninvasive hemoglobin measurement has been offered by devices using advanced pulse oximetry technology. Accuracy has been established in healthy adults as well as in surgical and intensive care unit patients but not in the setting of acute hemorrhage. In this study, we evaluated the accuracy of such a device in the clinical setting of preoperative phlebotomy thereby mimicking a scenario of acute blood loss. Methods: This prospective study included patients undergoing surgical repair of congenital heart disease (CHD) for whom preoperative phlebotomy was planned. Blood was removed after the induction of anesthesia and prior to the start of the surgical procedure. Replacement with crystalloid was guided by hemodynamic variables and cerebral oxygenation measured by near-infrared spectroscopy. Hemoglobin was measured by bedside whole blood analysis (total hemoglobin [tHb]) before and after phlebotomy, and concurrent measurements from the pulse co-oximeter (noninvasive, continuous, or spot-check testing of total hemoglobin [SpHb]) were recorded. Results: The study cohort included 45 patients ranging in age from 3 months to 50 years. Preoperative phlebotomy removed an average of 9.2 mL/kg of blood that was replaced with an average of 7.2 mL/kg of crystalloid. The pre- and postphlebotomy tHb values were 13.0 ± 1.9 and 12.4 ± 1.8 g/dL, respectively. The absolute difference between the tHb and SpHb (▵Hb) was 1.2 ± 0.1 g/dL. Bland-Altman analysis revealed a bias of 0.1 g/dL, a precision of 1.5 g/dL, and 95% limits of agreement of −2.8 to 3.1 g/dL. In 52.2% of the sample sets, the SpHb was within 1 g/dL of the actual hemoglobin value (tHb), and in 80% of the sample sets, the SpHb was within 2 g/dL. No variation in the accuracy of the deviation was noted based on the patient’s age, weight, or type of CHD (cyanotic versus acyanotic). Conclusion: The current study demonstrates that the accuracy of continuous, noninvasive hemoglobin measurement was not affected by acute blood loss simulated by preoperative phlebotomy. Although the device provided a clinically acceptable correlation with the actual hemoglobin value and offers the value of a continuous trend monitor, given the precision of the device, it does not appear that actual transfusion decisions can be based on the device alone.

Utility of screening questionnaire, obesity, neck circumference, and sleep polysomnography to predict sleep‐disordered breathing in children and adolescents

Polysomnography (PSG) remains the gold standard for diagnosing obstructive sleep apnea (OSA) and sleep‐disordered breathing in children. Yet, simple screening tools are needed as it is not feasible to perform PSG in all patients with possible OSA.

Current Practices Regarding Codeine Administration Among Pediatricians and Pediatric Subspecialists

Pharmacogenomic studies have revealed a wide variation in the metabolism of codeine to its active metabolite, morphine. A particular subset of patients, known as ultrarapid metabolizers, possesses multiple copies of the CYP2D6 gene responsible for codeine metabolism. This has been linked to serious morbidity and mortality in pediatric patients leading to considerable debate regarding the use of codeine for analgesia in the pediatric population. The current study surveyed the current practice of codeine prescription in pediatric health care providers from a single tertiary care pediatric hospital. Of the 298 responders, 43.3% (129 of 298) continue to prescribe codeine for pain management in children. The vast majority of codeine prescribers were primary health care providers (89.1%). Most of the primary care practitioners were in office-based (42.6%) or hospital-based (45.7%) group practices. There was no significant difference in codeine use based on years of experience. Given the risks associated with this practice, increased education targeting this group appears warranted.

Effect of cuffed and uncuffed endotracheal tubes on the oropharyngeal oxygen and volatile anesthetic agent concentration in children.

BACKGROUND Over the past 5 years, there has been a change in the clinical practice of pediatric anesthesiology with a transition to the use of cuffed instead of uncuffed endotracheal tubes (ETTs) in infants and children. As the trachea is sealed, one advantage is to eliminate the contamination of the oropharynx with oxygen which should be advantageous during adenotonsillectomy where there is a risk of airway fire. The current study prospectively assesses the oropharyngeal oxygen and volatile anesthetic agent concentration during adenotonsillectomy in infants and children. METHODS Following the induction of general anesthesia in patients scheduled for adenoidectomy, tonsillectomy or adenotonsillectomy, the trachea was intubated. The use of a cuffed or uncuffed ETT and the use of spontaneous (SV) or positive pressure ventilation (PPV) were at the discretion of the anesthesia team. The oxygen concentration was kept at 100% oxygen until the study was completed. Following placement of the mouth gag, the otolaryngolist placed into the oropharynx a small bore catheter, which was attached to a standard anesthesia gas monitoring device which sampled the gas at 150mL/min. The concentration of the oxygen and the concentration of the anesthetic agent in the oropharynx were measured for 5 breaths. RESULTS The cohort for the study included 200 patients ranging in age from 1 to 18 years. With the use of a cuffed ETT and either SV or PPV, the oxygen concentration in the oropharynx was 20-21% and the volatile agent concentration was 0% in all 118 patients. With the use of an uncuffed ETT and the administration of 100% oxygen, there was significant contamination of the oropharynx noted during both PPV and SV. The mean oxygen concentration was 71% during PPV with an uncuffed ETT and 65% during SV with an uncuffed ETT. In these patients, the oropharyngeal oxygenation concentration exceeded 30% in 73 of the 82 patients (89%). The oropharyngeal oxygen and agent concentration was greater when the leak around the uncuffed ETT was ≥10cmH(2)O versus less than 10cmH(2)O and when the leak around the uncuffed ETT was ≥15cmH(2)O versus less than 15cmH(2)O. CONCLUSIONS With the use of an uncuffed ETT and the administration of 100% oxygen, there was significant contamination of the oropharynx noted during both PPV and SV. The oropharyngeal concentration of oxygen is high enough to support combustion in the majority of patients. The use of a cuffed ETT eliminates oropharyngeal contamination with oxygen during the administration of anesthesia and may be useful in limiting the incidence of an airway fire.

Cuffed endotracheal tubes in infants and children: A technique to continuously measure the intracuff pressure

OBJECTIVES Various devices have been used to measure the intracuff pressure (CP) of an endotracheal tube at the time of inflation; however, no device has found widespread acceptance for the continuous monitoring of CP. We devised a simple method to continuously measure the CP using an invasive pressure monitoring setup (IPMS), which is used routinely in the operating room to monitor arterial or central venous pressures. The accuracy of the device was compared to those obtained from a commercially available and clinically used manometer (MM). METHODS Size 4.0, 5.0 and 6.0 mm ID cETTs were placed into one of 3 sizes of polyvinylchloride (PVC) tubes. The cuff of the cETT was inflated after inserting the cETT into the PVC pipes. After inflation, the CP was simultaneously checked using the MM and the IPMS. A total of 100 simultaneous (IPMS and MM) readings were obtained from each of the 3 sizes of cETT with the intracuff pressure randomly varying between 10 and 40 cmH₂O. Statistical analysis included a Bland-Altman comparison to determine the bias, mean, and 95% levels of agreement (LOA), and a linear regression analysis. RESULTS Linear regression analysis demonstrated an R(2) value of 0.988, 0.9899, and 0.9879 when comparing the pressure from the IPMS and MM from the 4.0, 5.0 and 6.0 mm cETT, respectively. CONCLUSIONS A standard IPMS can be used to continuously monitor intracuff pressure with the use of a cETT. Although various techniques can be used safely to avoid hyperinflation of the cuff, they provide only an instantaneous measure of the CP. The current technique allows for continuous monitoring of CP during prolonged cases or in other clinical scenarios when such monitoring is required.

Time to talk about work-hour impact on anesthesiologists: The effects of sleep deprivation on Profile of Mood States and cognitive tasks.

A physicians fatigue raises significant concerns regarding personal and patient safety. Effects of sleep deprivation on clinical performance and the quality of patient care are major considerations of todays health care environment.

Accuracy of the CNAP™ monitor, a noninvasive continuous blood pressure device, in providing beat-to-beat blood pressure readings in pediatric patients weighing 20–40 kilograms

During perioperative care, the continuous measurement of blood pressure (BP) provides superior physiologic monitoring to intermittent techniques. However, such monitoring requires placement of an intraarterial catheter, which may be time‐consuming or associated with adverse events and technical difficulty. A noninvasive, continuous BP monitoring device has been studied in the adult population. This study prospectively assesses its accuracy in pediatric patients, weighing 20–40 kg.

Accuracy of the CNAP monitor, a noninvasive continuous blood pressure device, in providing beat-to-beat blood pressure readings in the prone position

STUDY OBJECTIVE To assess the accuracy of a noninvasive continuous arterial pressure (CNAP) monitor in patients who are positioned prone in the operating room. DESIGN Prospective study. SETTING Operating room at a childrens hospital. PATIENTS 20 pediatric patients, aged 13.8 ± 2 years, and weight 63.7 ± 18.8 kg, scheduled for surgery in the prone position, and for which arterial catheter placement was planned. INTERVENTIONS Measurements were recorded with an arterial line (AL) and a new noninvasive continuous blood pressure (BP) monitor. MEASUREMENTS Systolic (SBP), diastolic (DBP), and mean arterial (MAP) pressure readings were captured from an arterial cannula and the CNAP device every minute during anesthesia. MAIN RESULTS The study cohort consisted of analysis of 4104 pairs of SBP, DBP, and MAP values, which showed an absolute difference between the AL and CNAP device readings of 7.9 ± 6.3 mmHg for SBP, 5.3 ± 4.3 mmHg for DBP, and 4.6 ± 3.9 mmHg for MAP. Bland-Altman analysis of MAP values showed a bias of 0.26 mmHg, with upper and lower limits of agreement of 12.18 mmHg and -11.67 mmHg, respectively. CNAP readings deviated from arterial values by ≤ 5 mmHg in 67% of MAP values, 59% of DBP values, and 43% of SBP readings. The difference was ≤ 10 mmHg for 94% of MAP readings, 90% of DBP values, and 73% of SBP readings. CONCLUSIONS During prone positioning, the CNAP monitor provided clinically acceptable accuracy for MAP values, similar to those reported in adults in the supine position.

Pain management following myringotomy and tube placement: Intranasal dexmedetomidine versus intranasal fentanyl

PURPOSE Despite the brevity of the procedure, bilateral myringotomy and tympanostomy tube placement (BMT) can result in significant postoperative pain and discomfort. As the procedure is frequently performed without intravenous access, non-parenteral routes of administration are frequently used for analgesia. The current study prospectively compares the efficacy of intranasal (IN) dexmedetomidine with IN fentanyl for children undergoing BMT. METHODS This prospective, double-blinded, randomized clinical trial included pediatric patients undergoing BMT. The patients were randomized to receive either IN dexmedetomidine (1 μg/kg) or fentanyl (2 μg/kg) after the induction of general anesthesia with sevoflurane. All patients received rectal acetaminophen (40 mg/kg) and the first 50 patients also received premedication with oral midazolam. Postoperative pain and recovery were assessed using pediatric pain and recovery scales, and any adverse effects were monitored for. RESULTS The study cohort included 100 patients who ranged in age from 1 to 7.7 years and in weight from 8.6 to 37.4 kg. They were divided into 4 groups with 25 patients in each group: (1) midazolam premedication+IN dexmedetomidine; (2) midazolam premedication+IN fentanyl; (3) no premedication+IN dexmedetomidine; and (4) no premedication+IN fentanyl. Pain scores were comparable when comparing groups 2, 3 and 4, but were higher in group 1 (midazolam premedication with IN dexmedetomidine). There was no difference in total time in the post-anesthesia care unit (PACU) or time from arrival in the PACU until hospital discharge between the 4 groups. The heart rate (HR) was significantly lower in group 3 when compared to the other groups at several different times after arrival to the PACU. No clinically significant difference was noted in blood pressure. CONCLUSION Following BMT, when no premedication is administered, there was no clinical advantage when comparing IN dexmedetomidine (1 μg/kg) to IN fentanyl (2 μg/kg). The addition of oral midazolam as a premedication worsened the outcome measures particularly for children receiving IN dexmedetomidine.