Short Communication: Lumbar Plexus Block versus Suprainguinal Fascia Iliaca Block to Provide Analgesia Following Hip and Femur Surgery in Pediatric-Aged Patients - An Analysis of a Case Series.

INTRODUCTION: For surgical procedures involving the hip and femur, various regional anesthetic techniques may be used to provide analgesia. Although there has been an increase in the use of lumbar plexus block (LPB), the technique may be time consuming and associated with complications. Suprainguinal fascia iliaca compartment block (FICB) is a potentially easier and safer alternative. The current study prospectively compares LPB with suprainguinal FICB. METHODS: This prospective, double-blinded, randomized, study included patients undergoing elective orthopedic procedures of the hip and/or femur. All study patients received general anesthesia with randomization to either an LPB or suprainguinal FICB using 0.5% ropivacaine with epinephrine and dexamethasone. Postoperative pain control was achieved with intravenous hydromorphone delivered by patient-controlled analgesia with scheduled acetaminophen and ketorolac. Outcome data included time to perform the block, perioperative opioid consumption, postoperative pain scores (VAS) and hospital length of stay. RESULTS: The study cohort included 15 patients between the ages of 7 and 16 years (LPB N = 7, FICB N = 8). The median block time was 6 minutes (IQR: 4.11) for the LPB group and 3 minutes (IQR: 3.6) for the FICB group (p = 0.107). Median postoperative pain scores were 4 (IQR: 0.6) for the LPB group and 2 (IQR: 0.5) for the FICB group (p = 0.032). There were no differences in the intraoperative or postoperative opioid and NSAID use between the two groups. DISCUSSION: The suprainguinal FICB provides analgesia that is at least as effective as a LPB following hip and femur surgery. Time to perform the block was shorter with the FICB due to the supine patient position and limited needle trajectory. Although we noted no adverse effects, the superficial needle trajectory of the FICB offers a less invasive approach and the potential for decreased risks of adverse effects.

Choosing endotracheal tube size in children: Which formula is best?

OBJECTIVES: Various formulae have been suggested to calculate the appropriate sized endotracheal tube in children. The current study prospectively compares three commonly used formulae for selection of cuffed endotracheal tubes in children. METHODS: Patients were randomized to one of three formulae (Duracher, Cole, or Khine) to determine the size of the cuffed endotracheal tube for endotracheal intubation. The fit of the tube was noted and intracuff pressure was measured using a manometer. The postoperative incidence of stridor, throat pain/soreness, and hoarseness was noted in the post-anesthesia care unit at 2, 4 and 24 h after the procedure. RESULTS: The study cohort included 135 patients less than or equal to 8 years, equally divided into three groups based on age, weight, and gender. There was no difference in the intracuff pressure, the volume required to seal the airway, or the number of times in which the intracuff pressure was greater than or equal to 20 or 30 cm H2O among the three groups. Six tube changes were required in the Cole group while no tube changes were required in the Duracher group (p < 0.05). The postoperative incidence of adverse events (throat pain, hoarseness, and stridor) at 0-2 h, 2-4 h, and 24 h was higher in the Cole group when compared to the Duracher group. CONCLUSION: When using an endotracheal tube with a polyurethane cuff, the Duracher formula provided the best estimate for choosing the correct size.

Evaluation of postoperative analgesia in pediatric patients after hip surgery: lumbar plexus versus caudal epidural analgesia.

Background:There continues to be focus on the value of regional and neuraxial anesthetic techniques when combined with general anesthesia to improve postoperative analgesia. The reported advantages include decreased postoperative opioid requirements, decreased medication-related adverse effects, decreased hospital length of stay, and increased patient satisfaction. Orthopedic procedures of the hip may be amenable to such techniques as there is significant postoperative pain with the requirement for hospital admission and the administration of parenteral opioids. Given the surgical site, various regional anesthetic techniques may be used to provide analgesia including caudal epidural anesthesia (CEA) or lumbar plexus blockade (LPB). Purpose: The objective of this study was to assess the effectiveness of LPB versus CEA as an analgesic thechnique for patients undergoing elective hip surgery from the opioid consumption and pain scores perspective. Patients and methods : The current study retrospectively reviews our experience with CEA and LPB for postoperative analgesia after hip surgery in the pediatric population. Regional anesthesia technique was reviewed as well as opioid requirements and pain scores. Results: The study cohort included 61 patients, 29 who received an LPB and 32 who received CEA. No difference was noted in the demographics between the two groups. Intraoperative opioid use was 0.7 (IQR: 0.5, 1.1) mg/kg of oral morphine equivalents (MEs) in the LPB group compared to 0.6 (IQR: 0.5, 0.9) in the CEA group (p=0.479). Postoperative opioid use over the first 48 hrs was 4 (IQR: 1, 6) mg/kg of oral ME in the LPB group, compared to 2 (interquartile range [IQR]: 1, 3) in the CEA group (p=0.103). Over the first 24 hrs after surgery, the median pain score in the LPB group was 5 (IQR: 1-6), compared to 3 (IQR: 0, 5) in the CEA group (p=0.014).Conclusion: These retrospective data suggest a modest postoperative benefit of CEA when compared to LPB following hip surgery in the pediatric population. Postoperative pain scores were lower in patients receiving CEA; however, no difference in the intraoperative or postoperative opioid requirements was noted between the two groups.

Intracuff pressure during one-lung ventilation in infants and children.

OBJECTIVE: We prospectively evaluated intracuff pressure (IP) during one-lung ventilation (OLV) to characterize potential risk associated with overinflation of the cuff used for OLV. DESIGN: Prospective observational study over a 2-year period, in infants and children undergoing thoracic surgery. The IPs of the tracheal and bronchial balloon were measured using a manometer and compared to a previously recommended threshold of 30 cmH2O. Data were compared by the device type used to achieve OLV. SETTING: Freestanding tertiary-care pediatric hospital. PARTICIPANTS: Patients ≤18 years of age undergoing thoracic procedures requiring OLV. INTERVENTIONS: Measurement of IP. MEASUREMENTS AND MAIN RESULTS: Thirty patients were enrolled (age 5 months-18 years) with a median weight of 28 kg. Median tracheal and bronchial IPs were 32 cmH2O (range: 11, 90) and 44 cmH2O (range: 10, 100), respectively. The tracheal and bronchial IPs exceeded 30 cmH2O in 13 of 20 patients (65%) and 21 of 30 patients (70%), respectively. CONCLUSIONS: IP was high and in excess of recommended levels in most children undergoing OLV. Continuous monitoring of IP may be indicated during OLV to address the risks involved and ensure the prevention of complications related to high IP. TYPE OF STUDY: Prospective comparative study. LEVEL OF EVIDENCE: Level II.

A comparison of supraglottic devices in pediatric patients.

BACKGROUND: When managing patients with a difficult airway, supraglottic airways (SGAs) have been used as rescue devices or to serve as a conduit for endotracheal intubation. The current study compares various clinical outcomes, including the bronchoscopic view of the glottis when using 2 SGAs, the Air-Q® laryngeal mask airway (LMA) and the i-gel® SGA, in pediatric patients. METHODS: Patients ≤18 years of age were prospectively randomized to receive either the Air-Q® LMA or the i-gel® SGA. Following SGA placement, a flexible fiberoptic bronchoscope was inserted through the SGA to visualize the glottis. Time taken to obtain the bronchoscopic view and place the SGA, and the ability to seal the airway at 20 cmH2O were compared. The bronchoscopic view obtained was graded as follows: 1) glottic aperture seen completely; 2) glottic aperture seen partially with visual obstruction <50%; 3) glottic aperture seen, but visual obstruction >50%; and 4) glottic aperture not seen. RESULTS: Fifty patients were enrolled and 48 (22/26 male/female) were included in the analysis. Median age was 13 years (IQR: 7, 16) and median weight was 49 kg (IQR: 25, 70). The Air-Q® LMA and i-gel® SGA groups did not differ in device placement time (median of 19 vs 21 seconds; 95% CI of difference in medians: - 2 to 7; P=0.331), the time to achieve fiberoptic view of the glottis (median of 25 vs 21 seconds; 95% CI of difference: - 9 to 8; P=0.489) or the grade of the bronchoscopic view of the airway. Eight Air-Q® and 6 i-gel® supraglottic devices sealed the airway at 20 cmH2O. DISCUSSION: The time required for successful placement of the SGA, the time required for bronchoscopic view, and the quality of bronchoscopic view through the Air-Q® LMA and the i-gel® SGA did not differ.

Management of the Difficult Airway in the Pediatric Patient.

Loss of airway control in children, if not resolved quickly, will lead to devastating consequences. Successful management of the pediatric difficult airway, both anticipated and unanticipated, is facilitated by preprocedure assessment and preparation. Accessibility of and continued hands-on training with modern airway instruments, familiarization with difficult airway guidelines, and collaboration with multidisciplinary airway teams can aid in the management of the difficult pediatric airway. This review outlines the importance of airway assessment and advanced airway equipment for children. It also discusses difficult airway management techniques and algorithms for the management and rescue of the pediatric difficult airway.

Sugammadex to reverse neuromuscular blockade and provide optimal conditions for motor-evoked potential monitoring.

Sugammadex is a novel pharmacologic agent, which reverses neuromuscular blockade (NMB) via a mechanism that differs completely from acetylcholinesterase inhibitors. By encapsulating rocuronium, sugammadex can provide recovery of neuromuscular function even when there is a profound degree of NMB. We report anecdotal experience with the use of sugammadex to reverse NMB to facilitate intraoperative neurophysiological monitoring (motor evoked potentials) in an adolescent with scoliosis during posterior spinal fusion. Its potential application in this unique clinical scenario is discussed, and potential dosing schemes are reviewed.

Cuffed endotracheal tubes in children: the effect of the size of the cuffed endotracheal tube on intracuff pressure.

BACKGROUND: In children, the size of the cuffed endotracheal tube is based on various age-based formulas. However, such formulas may over or underestimate the size of the cuffed endotracheal tube. There are no data on the impact of different-sized cuffed endotracheal tubes (ETT) on the intracuff pressure in children. AIM: The current study measures intracuff pressure with different-sized cuffed ETT. METHOD: The study was conducted in an in vitro and in vivo phase. For the in vitro phase, 10 cuffed ETT of size 4.0, 4.5, and 5 mm internal diameter (ID) each were randomly placed inside a 1.0 cm ID plastic tube (mimicking the trachea), which was in turn connected to a 1 l test lung. After inflation of the cuff using the air leak test at a continuous positive airway pressure of 20 cmH2 O, the intracuff pressure was measured. The in vivo phase was conducted in 100 children (4-8 years) and were randomly divided into two groups to receive either a cuffed endotracheal tube based on the Khine formula (Group R) or a cuffed endotracheal tube that was a half-size (0.5 mm ID) smaller (Group S). Following the inflation of the cuff to seal the trachea, the intracuff pressure was measured. RESULTS: In the in vitro phase, the intracuff pressure was 45 ± 6, 23 ± 1, and 14 ± 6 cmH2 O with size 4.0, 4.5, and 5 mm ID cuffed ETT, respectively (F-test P < 0.001 for difference among three groups). In the in vivo phase, the mean intracuff pressure in Group R was 25 ± 19 cmH2 O vs 37 ± 35 cmH2 O in Group S (95% CI of difference: 1, 23; P = 0.039). CONCLUSION: If the cuffed endotracheal tube is too small, the trachea can still be sealed by inflating the cuff with additional air. However, this transforms the cuff from the intended high-volume, low-pressure cuff to an undesirable high-volume, high-pressure cuff.

The Effect of Transesophageal Echocardiography Probe Placement on Intracuff Pressure of an Endotracheal Tube in Infants and Children.

OBJECTIVES: To evaluate the effects of transesophageal echocardiography (TEE) probe insertion on the endotracheal cuff pressure (CP). DESIGN: Prospective observational study. SETTING: Single standing, not-for-profit pediatric hospital. PARTICIPANTS: A total of 80 pediatric patients (aged 6 days to 18.4 years) who underwent cardiac surgery and intraoperative TEE. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Following anesthesia induction and endotracheal intubation, the CP was recorded at 4 points: before the insertion of the TEE (P1), at TEE insertion (P2), during TEE examination (P3), and after the probe was advanced into the stomach (P4). Twenty patients were enrolled in each of the following age groups:<1 year of age; 1-4 years of age; 5-8 years of age; and 9-18 years of age. CP was compared between pairs of time points using paired t-tests, and differences in CP over time were compared among age groups using repeated-measures analysis of variance. CP at P1, P2, P3, and P4 was 18.7±11.6, 26.7±14.4, 22.3±12.4, and 20.6±12.6 cmH2O, respectively. Although CP significantly increased from P1 to P2 (p<0.001), there was no significant difference between P1 and P4 (95% CI; -0.3 to 4.1; p = 0.083). There was no significant difference in CP change based on the age of the patient. CONCLUSION: Following a transient increase in CP with TEE probe insertion, the CP returned to baseline after the tip of the TEE probe was advanced into the stomach. There was no variation among age groups in the magnitude of the CP change during the study.

Changes in intracuff pressure of cuffed endotracheal tubes while positioning for adenotonsillectomy in children.

BACKGROUND: When using cuffed endotracheal tubes (cETTs), changes in head and neck position can lead to changes in intracuff pressure. AIM: The aim of this study was to assess the combined effect of neck extension, shoulder roll placement, and Crowe-Davis retractor use during adenotonsillectomy on the intracuff pressure of cETTs in children. METHODS: Patients <18 years of age undergoing adenotonsillectomy under general anesthesia following the placement of a cETT were included in the study. After inflation of the cuff to seal the trachea, using the leak test, baseline intracuff pressure was recorded and then continuously monitored. After neck extension, placement of a shoulder roll, insertion of the Crow-Davis retractor, suspension from a Mayo stand, and positioning for surgery, the intracuff pressure was recorded again. RESULTS: The study cohort included 84 patients, ranging in age from 0.9 to 17 years (5.7 ± 3.9 years). In 46 patients (54.8%), the intracuff pressure increased from baseline after positioning for adenotonsillectomy. In 12 of these patients (14.3%), the intracuff pressure was >30 cm H2O. The intracuff pressure decreased in 28 patients (33.3%), while no change was noted in 10 patients (11.9%). Overall, the general trend was an increase in intracuff pressure from 15.9 ± 7.8 cm H2O to 18.9 ± 11.6 cm H2O. CONCLUSION: Both increases and decreases in the intracuff pressure may occur following positioning of the pediatric patient for adenotonsillectomy. An increase in intracuff pressure may result in a higher risk of damage to the tracheal mucosa. A decrease in the intracuff pressure can result in an air leak resulting in inadequate ventilation, increased risk of aspiration, and even predispose to airway fire if oxygen-enriched gases are used. Continuous intracuff pressure monitoring or rechecking the intracuff pressure after positioning for adenotonsillectomy may be indicated.

Oropharyngeal oxygen and volatile anesthetic agent concentration during the use of laryngeal mask airway in children.

BACKGROUND: The laryngeal mask airway is increasingly used as an airway adjunct during general anesthesia. Although placement is generally simpler than an endotracheal tube, complete sealing of the airway may not occur, resulting in contamination of the oropharynx with anesthetic gases. Oropharyngeal oxygen enrichment may be one of the contributing factors predisposing to an airway fire during adenotonsillectomy. The current study prospectively assesses the oropharyngeal oxygen and volatile anesthetic agent concentration during laryngeal mask airway use in infants and children. METHODS: Following the induction of general anesthesia and placement of a laryngeal mask airway, the oropharyngeal gas sample was obtained by placing a 14-gauge catheter attached to the gas sampling tube into the oropharynx above the laryngeal mask airway. The oropharyngeal concentration of the oxygen and the anesthetic agent were recorded for five breaths during both spontaneous ventilation (SV) and positive pressure ventilation (PPV). RESULTS: The study included 238 patients. The oropharyngeal concentration of sevoflurane was >50% of the inspired sevoflurane concentration during SV in 10 of 238 (4.2%) patients and during PPV in 135 of 238 (56.7%) patients. Similarly, during SV and PPV, the oropharyngeal oxygen concentration was >21% in 30 of 238 (12.6%) patients and in 188 of 238 (79%) patients, respectively. Significantly, we also noticed that the oropharyngeal oxygen concentration exceeded 50% in 5 of 238 (2.1%) patients during SV and in 139 of 238 patients (58.4%) patients during PPV. CONCLUSIONS: With the use of a laryngeal mask airway and the administration of 100% oxygen, there was significant contamination of the oropharynx during both PPV and SV. The oropharyngeal concentration of oxygen was high enough to support combustion in a significant number of patients. The use of a laryngeal mask airway does not ensure sealing of the airway and may be one risk factor for an airway fire during adenotonsillectomy.

A Lousy Reason for Surgery Cancellations.

Cancellation of surgery has significant adverse impact on patients, health care providers, and their associated facilities. Although head lice infestation has not been shown to be associated with adverse surgical outcomes, it often prompts case cancellation by surgical and anesthesia personnel. The purpose of our study was to evaluate the extent and impact of surgery cancellations due to head lice infestation. In our study, a total of 9 patients were cancelled over a 3-year period. Although there is no direct evidence to show that head lice infestation poses a risk to surgical outcomes, the possibility of underlying secondary bacterial infection at the skin excoriation site is often the concern in these patients. This study offers the first investigation into the impact of head lice infections on operating room cancellations, which may prove to be a potential source of intervention to prevent cancellations.

An in vitro and in vivo validation of a novel color-coded syringe device for measuring the intracuff pressure in cuffed endotracheal tubes.

BACKGROUND: The clinical practice of pediatric anesthesiology has changed with a transition to the use of cuffed endotracheal tubes (ETTs) in infants and children. The monitoring of intracuff pressure has been suggested as one means to limit the potential for damage to the tracheal mucosa. The current study evaluates the accuracy of a novel, color-coded syringe device which provides three zones (green, clear, and red) to estimate the intracuff pressure. METHOD: The study was conducted in two phases. Phase 1 was an in vitro study where cuffed ETTs of sizes 4.0 mm, 5.0 mm and 6.0 mm ID were placed into polyvinylchloride tubing of appropriate sizes. A manometer and the syringe device were simultaneously attached to measure the intracuff pressure at the middle of the 3 different zones on the device (red, clear, and green). Phase 2 was an in vivo study where the syringe device and the manometer were simultaneously attached to the pilot balloon to measure the intracuff pressure and the corresponding zone on the color-coded syringe following endotracheal intubation. Statistical analysis included a descriptive reporting of the mean ± SD, median, range, and 95% confidence intervals (CI) of the actual intracuff pressure readings at the three zones of the syringe device during both its in vitro and in vivo use. RESULTS: For phase 1 of the study, the 95% CI for the green, clear, and red zones were 21.5-21.8, 29.2-29.5, and 46.5-47.4 cmH2O respectively. This correlated well with the manufacturer reported values of 20-30, 30-40, and 40-60 cmH2O for the 3 zones (green, clear, and red respectively). Phase 2 of the study included 200 patients ranging in age from 0.1 to 21.8 years (6.7 ± 5.1 years) and in weight from 4.0 to 129.1 kilograms (29.4 ± 23.3 kgs). The size of the ETTs ranged from 3.0 to 7.0 mm ID. The intracuff pressure measured by the manometer ranged from 4 to 65 cmH2O (27.6 ± 9.7 cmH2O). The 95% CI for the green, clear, and red zones were 20.5-21.7, 27.7-29.1, and 41.2-46.5 cmH2O respectively. There was no significant differences noted when comparing different patient ages or sizes of ETT. CONCLUSION: The current study demonstrates a clinically acceptable correlation between the zones on this novel, color-coded syringe device and the actual measurement of the intracuff pressure obtained by a manometer for both in vitro and in vivo use. This device is a simple, reliable, portable and affordable method to monitor intracuff pressure.

Effect of dexmedetomidine on the QT interval in pediatric patients undergoing general anesthesia.

BACKGROUND: Recent years have seen an increase in the use of dexmedetomidine in pediatric patients presenting for surgical procedures. However, only a limited number of studies have evaluated its effects on the QT interval in this patient group. To address this lack of knowledge, we have evaluated the effects of dexmedetomidine on the QT interval in children receiving sevoflurane anesthesia. METHODS: This study was a prospective case-control study in which pediatric patients presenting for anesthetic care were divided into two groups--the dexmedetomidine (D) and control (C) groups. Three electrocardiograms (ECGs) were obtained on each patient, including a baseline ECG (T1) prior to anesthetic induction and an ECG after the induction of anesthesia with sevoflurane (T2). In group D, the third ECG was obtained 2 min after the administration of dexmedetomidine, which in turn was started immediately after the T2 ECG reading (T3D); in group C, it was obtained 2 min after the T2 reading (T3C). Statistical analysis was performed using analysis of variance to compare the QT intervals at the three time points outlined above. RESULTS: A total of 50 patients were recruited to the study, ranging in age from 1 to 16 [mean 7.9 ± 4.1 (SD) years]. There were 25 patients in group C and 25 in group D. There were no statistical differences in the demographics between the 2 groups. In group C, the QTc was noted to increase progressively with the administration of sevoflurane (T3C vs. T1; P = 0.006). In group D, following the administration of dexmedetomidine, there was a significant decrease in the QTc relative to the post-induction value [436 ± 25 (T2) vs. 418 ± 17 ms (T3D); P < 0.01]. CONCLUSION: A progressive lengthening of the QTc interval following the administration of sevoflurane was observed in the control group. In the dexmedetomidine group, there was a significant shortening of the QTc interval following the administration of dexmedetomidine compared to the length of the post-induction QTc interval and when compared to the control group.

Changes in intracuff pressure of a cuffed endotracheal tube during surgery for congenital heart disease using cardiopulmonary bypass.

BACKGROUND: With the development of newer polyurethane cuffed endotracheal tubes (cETTs), there has been a shift in clinical practice among pediatric anesthesiologists. Despite improvements in design, excessive inflation of the cuff can still compromise tracheal mucosal perfusion. Several perioperative factors can affect the intracuff pressure (CP), and there is no consensus on safe CP in pediatric patients undergoing repair of congenital cardiac disease (CHD) utilizing cardiopulmonary bypass (CPB). In the current study, the CP was continuously monitored in pediatric patients undergoing surgery for CHD. METHODS: After IRB approval, this observational study was conducted on pediatric patients who underwent repair of CHD using CPB with a cETT in place. After anesthetic induction and endotracheal intubation, the cuff was inflated using the air leak technique while maintaining a continuous positive airway pressure of 20 cmH2 O. After inflation, the CP was continuously monitored throughout the procedure. In addition, temperature and mean arterial pressure (MAP) were also recorded. RESULTS: The study included 33 patients who ranged in age from 1 month to 15.3 years. Their weight ranged from 4.0 to 83.6 kg. Six patients were excluded from the analysis due to the need to add or remove air from the cuff, leaving 27 patients for data analysis for cuff pressure over time. The baseline CP at the time of inflation was 16.1 ± 7.6 cmH2 O. With the use of CPB and initiation of hypothermia, when compared to the baseline, the CP decreased by -0.7 ± 5.8 cmH2 O at 35-37°C, -9.1 ± 8.4 cmH2 O at 31-33°C, -7.8 ± 6.2 cmH2 O at 27-29°C, and -11.1 ± 6.0 cmH2 O at <27°C. With rewarming, the CP increased back to the baseline level (-3.5 ± 7.0 cmH2 O). CONCLUSION: There was a significant decrease in the CP during CPB and associated hypothermia. This may offer some protection for mucosal perfusion during CPB which is usually associated with lower than normal MAP. However, the decrease in the CP may compromise the tracheal seal which may not offer the intended protection for the airway from aspiration.

Neuraxial anesthesia in the presence of clinical anticoagulation: what are our options for pediatric patients?

The use of local anesthesia combined with general anesthesia to provide effective perioperative analgesia continues to increase in the pediatric population. Although neurological complications resulting from peridural hemorrhage following placement of neuraxial blockade is extremely rare in the absence of co-morbid conditions, the consequences can be devastating. Therefore, caution should be exercised, especially in patients receiving antithrombotic or thrombolytic therapy. We present two patients who received unplanned anticoagulation therapy perioperatively following placement of an epidural catheter for postoperative analgesia. Potential concerns with anticoagulation therapy in patients with epidural catheters are discussed and suggestions for the care of such patients are presented.

SUBMUCOSAL DISSECTION OF THE RETROPHARYNGEAL SPACE DURING NASAL INTUBATION.

Various complications have been reported with nasal endotracheal intubation including bleeding, epistaxis, bacteremia, damage to intranasal structures, and even intracranial penetration. We present two cases that required general anesthesia for dental surgery. Submucosal dissection of the retropharyngeal tissues occurred during attempted nasal endotracheal intubation. Previous reports of this complication are reviewed, treatment strategies presented, and potential maneuvers to prevent this complication suggested.

Changes in intracuff pressure of a cuffed endotracheal tube during prolonged surgical procedures.

BACKGROUND: With the introduction of redesigned cuffed endotracheal tubes (ETTs), there has been an increasing trend toward their use in pediatric patients. Despite improvements in design, an unintended and prolonged hyperinflation of the cuff can compromise tracheal mucosal perfusion. The current study prospectively monitors changes in intracuff pressure continuously in pediatric patients undergoing prolonged surgical procedures. METHODS: The study was conducted on pediatric patients who were scheduled to undergo prolonged surgical procedures (more than 4h) with a cuffed ETT. After placement of the cuffed ETT, the cuff was inflated using the air-leak test with a CPAP of 20cmH2O in the anesthesia circuit. After inflation, the inflating port of the pilot balloon was connected to the transducer of the invasive pressure monitoring device using our previously described technique to continuously measure the intracuff pressure. Measurements were recorded every 15min for the first 1h, and then every 30min throughout the surgical procedure. RESULTS: The study cohort included 30 patients who ranged in age from 1.2 to 17.6 years and in weight from 9.4 to 113.4kg. There were 16 boys and 14 girls. The size of the cuffed ETT ranged from 3.5mm to 8.0mm ID. The baseline intracuff pressure at the time of inflation was 17.6±8.8cmH2O. The absolute change in the intraoperative intracuff pressure when compared to the baseline intracuff pressure ranged from -25.8 to +16.3cmH2O. In 9 patients (30%), the decrease of the intracuff pressure was ≥10cmH2O. In 6 patients (20%), the increase of the intracuff pressure was ≥10cmH2O. In 5 of 30 patients (17%), the absolute intracuff pressure was greater than 30cmH2O at least once intraoperatively. In no patient, did the intracuff pressure remain the same as the baseline throughout the procedure. CONCLUSION: We noted significant variations in the intracuff pressure during prolonged surgical procedures. These unintended changes, both increases and decreases, may impact the perioperative course of patients. Our study suggests the need for continuously monitoring intracuff pressure if a cuffed ETT is used in children for prolonged surgical procedures.

An in vitro and in vivo validation of a novel monitor for intracuff pressure in cuffed endotracheal tubes.

BACKGROUND: The clinical practice of pediatric anesthesiology has changed with increasing use of cuffed endotracheal tubes (cETTs) in infants and children. To limit the risk of tracheal mucosal damage, regular monitoring of intracuff pressure (CP) is necessary. This study evaluates the efficacy and accuracy of a novel syringe device that provides a digital readout of the CP. METHODS: The study was conducted in two phases. In phase 1, an in vitro study, cETTs of sizes 4.0, 5.0, and 6.0 mm ID were placed into polyvinylchloride tubing of appropriate sizes. The cuffs were then inflated, and the CP was measured simultaneously using the syringe device and a manometer. In phase 2, an in vivo study on 200 pediatric patients, the syringe device and the manometer were simultaneously attached to the pilot balloon to measure the CP following endotracheal intubation. Statistical analysis included linear regression analysis and Bland-Altman comparison. RESULTS: Linear regression analysis of the in vitro study demonstrated an R2 value of 0.9989. Bias and precision were -1.92 ± 0.62 with 95% level of agreement (LOA) ranging from -3.13 to -0.72. For the in vivo study, the linear regression analysis demonstrated an R2 value of 0.9943. The bias and precision were -0.53 ± 0.68 with 95% LOA ranging from -1.86 to 0.81. CONCLUSION: The study has demonstrated clinically acceptable correlation between the CPs obtained from the standard manometer and the syringe device both in vitro and in vivo. This device is a simple, reliable, portable, and affordable method to monitor CP.