The ProSeal Laryngeal Mask Airway in Prone Patients: A Retrospective Audit of 245 Patients

Combined segmental spinal epidural for major spine surgery: a case report

A woman in her mid-50s, hesitant about general anaesthesia due to a difficult airway, opted for neuraxial anaesthesia for L4 laminectomy with pedicle screw fixation (L3-L5). Preoperatively, she received 150 µg buprenorphine and 1 mg midazolam. In lateral position, a T8-T9 epidural catheter was placed, followed by segmental spinal anaesthesia (2.5 mL 0.5% hyperbaric bupivacaine+30 µg clonidine) at T10-T11. Prone positioning was executed using standard techniques. During the 6-7 hours surgery, three 7 mL epidural top-ups (2% lignocaine epinephrine) were administered at 90 min intervals. Haemodynamics remained stable with 2.5 L crystalloids, 350 mL packed red cells and three ephedrine doses (6 mg each). Sedation included 150 µg buprenorphine and two 1 mg midazolam doses. Postoperatively, she received epidural 0.25% bupivacaine for 2 days, systemic analgesics and was discharged on the sixth day.

A Comparison of a Standard Macintosh Blade Laryngoscope, Pentax-AWS Videolaryngoscope and Intubrite Videolaryngoscope for Tracheal Intubation in Manikins in Sitting and Prone Positions: A Randomized Cross-Over Study

Background: Intubation of a patient in different positions may be done not only in emergency settings, but also in routine anesthesia (e.g., prone position for lumbar spine surgery). Methods: The aim of the study was to compare the classic Macintosh blade laryngoscope with two videolaryngoscopes: the Pentax-AWS and the Intubrite in a simulated scenario of a manikin placed in a sitting and prone position. Additionally, intubation with the use of all three devices was performed in a standard supine position as the control group. The time of intubation and the pressure exerted on the tongue was assessed. The ANOVA Friedman (analysis of variance) and Wilcoxon with Bonferroni correction tests were used for statistical analysis. Results: The time of intubation in a prone position was significantly shorter for the Pentax-AWS videolaryngoscope compared to the Macintosh and the Intubrite. There were no significant differences in the obtained results of the evaluated devices in sitting and standard positions. The lowest pressure exerted on the tongue was with the Pentax-AWS, followed by the Intubrite and the Macintosh laryngoscopes. Conclusions: The use of the Pentax-AWS was associated with faster tracheal intubation, creating lower pressure on tongue when compared with standard Macintosh and Intubrite laryngoscopes in both prone and sitting positions.

Supraglottic airway device versus a channeled or non-channeled blade-type videolaryngoscope for accidental extubation in the prone position: A randomized crossover manikin study

BACKGROUND

It is very rare but challenging to perform emergency airway management for accidental extubation in a patient whose head and neck are fixed in the prone position when urgently turning the patient to the supine position would be unsafe. The authors hypothesized that tracheal intubation with a videolaryngoscope would allow effective airway rescue in this situation compared with a supraglottic airway device and designed a randomized crossover manikin study to test this hypothesis.

METHODS

The authors compared airway rescue performances of the 3 devices-the ProSeal laryngeal mask airway (PLMA; Teleflex Medical, Westmeath, Ireland) as a reference; the Pentax AWS (AWS; Nihon Kohden, Tokyo, Japan) as a channeled blade-type videolaryngoscope; and the McGRATH videolaryngoscope (McGRATH; Medtronic, Minneapolis, MN) as a nonchanneled blade type in a manikin fixed to the operating table in the prone position. Twenty-one anesthesiologists performed airway management on the prone manikin with the 3 devices, and the time required for intubation/ventilation and the success rates were recorded.

RESULTS

The median (range) intubation/ventilation times with the PLMA, AWS, and McGRATH were 24.5 (13.5-89.5) s, 29.9 (17.1-79.8) s, and 46.7 (21.9-211.7) s, respectively. There was no significant difference in intubation/ventilation times between the PLMA and AWS. The AWS permitted significantly faster tracheal intubation than did the McGRATH (P = 0.006). The success rates with the PLMA (100%) and AWS (100%) were significantly greater than that with the McGRATH (71.4%). Airway management performance of the PLMA and AWS was comparable between devices and better than that of the McGRATH in the prone position.

CONCLUSIONS

Considering that tracheal intubation can provide a more secure airway and more stable ventilation than the PLMA, re-intubation with a channeled blade-type videolaryngoscope such as the AWS may be a useful method of airway rescue for accidental extubation in patients in the prone position.

Evaluation of performance of Streamlined Liner of the Pharynx Airway™, Laryngeal Mask Airway-ProSeal and endotracheal tube in prone position: A prospective, randomised study

Background and Aims:

Airway used in prone position should be efficacious and safe. The Streamlined Liner of the Pharynx Airway (SLIPA™) and Laryngeal Mask Airway-ProSeal (PLMA) provide better airway seal and protection against aspiration. We planned to evaluate the performance of SLIPA™, PLMA and endotracheal tube (ETT) in prone position.

Methods:

114 adult patients undergoing elective surgery in prone position under general anaesthesia were randomised into Group-T (ETT), Group-S (SLIPA™) and Group-P (PLMA). Airways were inserted in supine position and patients turned prone subsequently. Airway characteristics, ventilatory parameters and complications were noted. One-way analysis of variance, Mann–Whitney U-test and Chi-square or Fisher's exact test were used.

Results:

Tidal volumes, peak airway pressure and compliance were comparable at all times. Leak pressure was significantly higher (P < 0.001) in Group-T (mean leak pressure = 40 cmH₂O) when compared to Group-S and Group-P at all the times of recording, and there was no significant difference between Group-S and Group-P. The number of patients requiring airway/neck manipulation in prone position was significantly higher (P < 0.001) in Group-S (19 [55.9%]) when the three groups were compared (none in Group-T) and in comparison with Group-P (5 [14.7%], P < 0.001). On airway removal, the incidence of complications and airway reaction was significantly higher in Group-T. Group-S had a significantly higher incidence of dysphagia at 2 h postoperatively.

Conclusion:

ETT was most efficacious. SLIPA™ and PLMA were efficacious, safe and less stimulating to the airway during removal. More patients required SLIPA™ airway/neck manipulation.

Laryngeal Mask Ventilation During Lumbar Spine Neurosurgery in Knee-Chest Position is Feasible

BACKGROUND

This study describes our experience with laryngeal mask (LM) inserted after anesthetic induction in patients already in knee-chest position for lumbar neurosurgery.

METHODS

Airway management (need for LM repositioning, orotracheal intubation because of failed LM insertion), anticipated difficult airway, and airway complications were registered. Statistics were compared between groups with the t test or the χ test, as appropriate.

RESULTS

A total of 358 cases were reviewed from 2008 to 2013. Tracheal intubation was performed in 108 patients and LM was chosen for 250 patients (69.8%). Intubated patients had a higher mean age and rate of anticipated difficult airway; duration of surgery was longer (P<0.001, all comparisons). LM insertion and anesthetic induction proved effective in 97.2% of the LM-ventilated patients; 7 patients (2.8%) were intubated because of persistent leakage. Incidences with airway management were resolved without compromising patient safety.

CONCLUSION

LM airway management during lumbar neurosurgery in knee-chest position is feasible for selected patients when the anesthetist is experienced.

Supraglottic Airway Devices: the Search for the Best Insertion Technique or the Time to Change Our Point of View?

In the crowded world of supraglottic airway devices (SADs), many papers compare the easiness of insertion based on the different endpoints of an operator's satisfaction: first pass success, ventilation effectiveness, complications and morbidity. Proseal LMA^™ (Laryngeal Mask Airway, Teleflex Medical, Dublin, Ireland) has been extensively studied because on one hand it has a steeper learning curve and more complex insertion when compared with other SADs and on the other hand many alternative techniques are available to facilitate insertion. This research is part of a larger body of studies exploring the issue that some devices are more difficult to insert because of many features related to sizing, constructive material, airway conduit and cuff design, performance and last but not least experience. Nevertheless, the biggest question might be the search for a systematic categorization of insertion difficulty features and identification of criteria allowing the choice for the best device and consequently for the best insertion technique. Given that, as a result of many intrinsic characteristics of the device we are using, insertion might become the secondary issue to be considered only after we clearly identify what makes it difficult, and to be counterbalanced on the results we expect from the device, performance we can achieve and degree of airway protection it could grant. The aim of this narrative review is to consider which factors might affect or condition SAD insertion difficulty and to try identifying some criteria addressing physicians pertaining to the use of SADs in clinical practice.

Is segmental epidural anaesthesia an optimal technique for patients undergoing percutaneous nephrolithotomy?

Background and Aims:

Neuraxial anaesthesia has recently become popular for percutaneous nephrolithotomy (PCNL). We conducted a study comparing general anaesthesia (GA) with segmental (T₆–T₁₂) epidural anaesthesia (SEA) for PCNL with respect to anaesthesia and surgical characteristics.

Methods:

Ninety American Society of Anesthesiologists Physical Status-I and II patients undergoing PCNL randomly received either GA or SEA. Overall patient satisfaction was the primary end point. Intraoperative haemodynamics, epidural block characteristics, post-operative pain, time to rescue analgesic, total analgesic consumption, discharge times from post-anaesthesia care unit, surgeon satisfaction scores and stone clearance were secondary end points. Parametric data were analysed by Student's t-test while non-parametric data were compared with Mann–Whitney U-test.

Results:

Group SEA reported better patient satisfaction (P = 0.005). Patients in group GA had significantly higher heart rates (P = 0.0001) and comparable mean arterial pressures (P = 0.24). Postoperatively, time to first rescue analgesic and total tramadol consumption was higher in Group GA (P = 0.001). Group SEA had lower pain scores (P = 0.001). Time to reach Aldrete's score of 9 was shorter in group SEA (P = 0.0001). The incidence of nausea was higher in group GA (P = 0.001); vomiting rates were comparable (P = 0.15). One patient in group SEA developed bradycardia which was successfully treated. Eight patients (18%) had hypertensive episodes in group GA versus none in group SEA (P = 0.0001). One patient in GA group had pleural injury and was managed with intercostal drain. Stone clearance and post-operative haemoglobin levels were comparable in both groups.

Conclusion:

PCNL under SEA has a role in selected patients, for short duration surgery and in expert hands.

Ease of insertion of the laryngeal mask airway in pediatric surgical patients: Predictors of failure and outcome

BACKGROUND

Laryngeal mask airway (LMA) is an useful alternative to endotracheal tube for airway management. The risk of life-threatening adverse respiratory events during its use is rare, but we need to know about the risk-adjusted prediction of its insertion failure requiring rescue tracheal intubation and its impact on patient outcome.

MATERIALS AND METHODS

Five hundred patients; 6 months to 12-year-old, American Society of Anesthesiologists I and II scheduled to undergo elective surgical procedures that require general anesthesia were included in this study. LMA was inserted after induction of anesthesia. The insertion conditions, intra, and postoperative events were recorded. Our primary outcome variable was trial success from the first time.

RESULTS

We recorded 426 cases (85.2%) of first trial success with clear airway compared to 46 case (9.2%) of second trial success (P ≤ 0.001). Predictors of failure of first attempt of LMA insertion include abnormal airway anatomy (91%), body weight <16 kg and age below 5 years (44%), the use of LMA size of 1 and 1.5 (3.8%), the intraoperative lateral position (3.8%).

CONCLUSION

The data obtained from this study support the use of the LMA as a reliable pediatric supraglottic airway device, demonstrating relatively low failure rates. Predictors of LMA failure in the pediatric surgical population should be independently considered.

TRIAL REGISTRATION

The study is registered in the Australian and New Zealand clinical trial registry with the allocated trial number: ACTRN12614000994684. Web address of trial: http://www.ANZCTR.org.au/A CTRN12614000994684.aspx.

Comparison of the I-gel laryngeal mask airway with the LMA-supreme for airway management in patients undergoing elective lumbar vertebral surgery

BACKGROUND

The single-use supreme-laryngeal mask airway (LMA) [corrected] has been reported to be suitable for airway management in the prone position. However, there are a limited number of cases using the I-gel in the prone position. In this study, we compared the clinical use of the 2 devices in adult patients undergoing elective lumbar vertebral surgery in the prone position.

MATERIALS AND METHODS

Two hundred and sixty-four consecutive patients scheduled for lumbar surgery in the prone position were randomized to receive either the I-gel or the LMA [corrected] for airway management. All I-gels and LMAs [corrected] were inserted in the supine position by experienced anesthesiologists using standard techniques. Time and number of attempts needed for insertion, quality of ventilation, airway peak pressure, airway seal pressure, fiberoptic view, and complications were compared between the 2 groups.

RESULTS

No differences were observed in insertion time between groups. The I-gel required significantly more attempts at insertion (P<0.001). Airway seal pressure was lower in prone than in supine position in both groups (P<0.001). The I-gels provided a higher airway seal pressure ([28.4±5.4] vs. [24.8±4.6] cm H2O; P<0.001) in the prone position. There was no difference observed in fiberoptic view of the vocal cords between the 2 groups. The complication rate was low and was similar between the groups. There was little fluid in the mask of both the I-gel and the LMA [corrected] and the pH value was 6.8±0.7 versus 6.6±0.9, respectively.

CONCLUSIONS

The I-gel laryngeal mask airway can also be used safely in airway management of patients undergoing lumbar surgery in the prone position as well as the LMA [corrected].

Comparison of three supraglottic airway devices for airway rescue in the prone position: A manikin-based study

BACKGROUND

Accidental extubation during surgery in prone position can be life-threatening. Supraglottic airway devices (SAD) have been used successfully in such situations to rescue the airway. However, which SAD would be most appropriate in this setting has not been described in the literature.

AIMS

The aim of our study was to determine the most appropriate SAD for securing airway in a prone position during accidental extubation.

MATERIALS AND METHODS

In the study, Airway Trainer (Laerdal) manikin was used for studying insertion of three SADs; I-gel, Laryngeal Mask Airway ProSeal™ (PLMA) and LMA Classic™ (CLMA) in the prone position. Forty anesthesia resident doctors participated in this study. The time taken for insertion; ease of insertion and ventilation; bronchoscopic view; and insertion score were compared among the three groups.

RESULTS

The time taken for I-gel insertion was significantly lesser (12.89 ± 3.94 seconds) as compared to CLMA (17.07 ± 3.5 seconds) and PLMA (25 + 4.78 seconds). Least resistance was encountered in the insertion of I-gel, while maximum resistance was experienced in PLMA group (22.5% vs. 90%). The maneuver required for optimal positioning was observed in 27.5% of PLMA insertion, 2.5% in CLMA while no maneuver was required in any of the I-gel insertion. Ease of ventilation was comparable in all three SADs. The bronchoscopic view and insertion score were significantly higher with I-gel as compared to CLMA and PLMA.

CONCLUSION

All three SADs were successful as rescue devices during accidental extubation in the prone position. However, the ease of insertion was maximum with I-gel, followed by CLMA and PLMA.

A prospective study to evaluate and compare laryngeal mask airway ProSeal and i-gel airway in the prone position

Background:

Prone position is commonly used to provide surgical access to a variety of surgeries. In view of the advantages of induction of anesthesia in the prone position, we conducted a randomized study to evaluate and compare ProSeal laryngeal mask airway (LMA) and i-gel in the prone position.

Materials and Methods:

Totally, 40 patients of either sex as per American Society of Anesthesiologists physical status I or II, between 16 and 60 years of age, scheduled to undergo surgery in prone position were included in the study. After the patients positioned themselves prone on the operating table, anesthesia was induced by the standard technique. LMA ProSeal was used as an airway conduit in group 1 while i-gel was used in group 2. At the end of surgery, the airway device was removed in the same position.

Results:

Insertion of airway device was successful in first attempt in 16, and 17 cases in ProSeal laryngeal mask airway (PLMA) and i-gel groups, respectively. A second attempt was required to secure the airway in 4 and 3 patients in PLMA and i-gel groups, respectively. The mean insertion time was 21.8 ± 2.70 s for group 1 and 13.1 ± 2.24 s for group 2, the difference being statistically significant (P < 0.05). The mean seal pressure in group 1 was 36 ± 6.22 cm H₂ O and in group 2 was 25.4 ± 3.21 cm H₂ O. The difference was statistically significant (P < 0.05). 13 patients in group 1 had fiberoptic bronchoscopy (FOB) grade 1 while it was 6 for group 2. The remaining patients in both groups had FOB grade 2.

Conclusion:

Insertion of supraglottic airways and conduct of anesthesia with them is feasible in the prone position. The PLMA has a better seal while insertion is easier with i-gel.

Should we induce general anesthesia in the prone position?

PURPOSE OF REVIEW

For patients requiring surgery in the prone position, an alternative to a traditional supine induction is allowing the patient to position themselves comfortably prone and inducing anesthesia in that position. The purpose of this review is to examine the current literature and evaluate the safety of induction of anesthesia in the prone position.

RECENT FINDINGS

The first randomized trial comparing induction in the supine vs. prone position for patients requiring spinal surgery was published earlier this year and reported a time-saving benefit. Multiple case series report the feasibility of this approach; however, the potential benefits of prone induction, namely a reduction in pressure injuries and avoidance of complications of the turn itself, remain unproven. Increased familiarity with prone insertion of supraglottic airways is a useful tool in case of accidental intraoperative extubation in a patient who is already prone. Potential disadvantages include loss of the airway during induction, reduced ability to manage adverse hemodynamic consequences of induction and restriction to use of a supraglottic airway.

SUMMARY

The reviewed literature shows that elective prone induction of anesthesia using supraglottic airways, in select patients, is feasible and associated with very low complication rates; however, there is insufficient evidence to suggest that this should be done routinely.

Airway management evolution - in a search for an ideal extraglottic airway device

Extraglottic airway devices (EADs) are commonly used equipment for airway maintenance during elective procedures under general anaesthesia. They may be used also in other indications such as conduit for tracheal intubation or rescue airway device in prehospital medicine. Current classifications of the EADs lack systematic approach and therefore classification according to the sealing sites and sealing mechanisms is suggested in this review article. Modern EADs are disposable, latex-free devices made of plastic materials most commonly from polyvinylchloride (PVC). The bowl of uncuffed sealers is manufactured from different materials such as thermoplastic elastomers or ethylene-vinyl-acetate co-polymer. EADs create various physical forces exerted on the adjacent tissues which may contribute to different sealing characteristic of particular device or to variable incidence of postoperative complications. Desired features of an ideal EAD involve easy insertion, high insertion success rate even by inexperienced users, protection against aspiration of gastric contents and low incidence of postoperative complications such as sore throat, hoarseness, cough or swallowing difficulties.

ProSeal laryngeal mask airway™ insertion in the prone position: Optimal utilization of operation theatre personnel and time?

BACKGROUND

Positioning an anesthetized patient prone is challenging with regard to manpower requirement, time to surgical readiness and airway management. The ProSeal laryngeal mask airway™ (PLMA) is emerging as a suitable alternative, both as a primary and a rescue airway device to the tracheal tube (TT) for patients undergoing surgery in the prone position.

MATERIALS AND METHODS

In this prospective randomized study, 70 patients scheduled to undergo pilonidal sinus excision in prone position were allocated to two groups of 35 patients each, depending on the position of the patient at induction and device placement: Group S (device placed while supine) and Group P (device placed while prone). We compared the manpower requirement, time to surgical readiness, efficacy and safety of the PLMA for airway management in the two groups.

RESULTS

The number of personnel [5 (4-6) vs. 3 (3-3); P < 0.001] required for positioning the patient and surgical readiness time (22.1 ± 3 vs. 5.9 ± 0.9 min; P < 0.001) was higher in group S. There was no difference between the two groups with regard to efficacy and safety of the PLMA. Incidence of blood on the PLMA cuff and sore throat was comparable in the two groups (P = 1.000).

CONCLUSION

We conclude that induction and placing the PLMA in the prone position by experienced users require fewer personnel and reduces surgical readiness time.

Failure of the Laryngeal Mask Airway Unique™ and Classic™ in the Pediatric Surgical Patient

Background:

Although predictors of laryngeal mask airway failure in adults have been elucidated, there remains a paucity of data regarding laryngeal mask airway failure in children.

Methods:

The authors performed a retrospective database review of all pediatric patients who received a laryngeal mask anesthetic at their institution from 2006 to 2010. Device brands were restricted to LMA Unique™ (Cardinal Health, Dublin, OH) and LMA Classic™ (LMA North America, San Diego, CA), and primary outcome was laryngeal mask failure, defined as any airway event requiring device removal and tracheal intubation. Potential risk factors were analyzed with both univariate and multivariate techniques and included medical history, physical examination, surgical, and anesthetic characteristics.

Results:

Of the 11,910 anesthesia cases performed in the study, 102 cases (0.86%) experienced laryngeal mask failure. Common presenting features of laryngeal mask failures included leak (25%), obstruction (48%), and patient intolerance such as intractable coughing/bucking (11%). Failures occurred before incision in 57% of cases and after incision in 43%. Independent clinical associations included ear/nose/throat surgical procedure, nonoutpatient admission status, prolonged surgical duration, congenital/acquired airway abnormality, and patient transport.

Conclusions:

The findings of the study support the use of the LMA Unique™ and LMA Classic™ as reliable pediatric supraglottic airway devices, demonstrating relatively low failure rates. Predictors of laryngeal mask airway failure in the pediatric surgical population do not overlap with those in the adult population and should therefore be independently considered.

Routine intubation in the prone position

BACKGROUND

Tracheal intubation in the prone position has previously been reported only as a necessity in a very few emergency situations. It emerged at our clinic as a routine after invention of a test aimed at pinpointing a painful motion segment in patients with chronic low back pain who were candidates for lumbar fusion operation.

MATERIAL AND METHODS

During a 6-year period 247 consecutive patients were treated at our clinic, 91 men and 156 women, mean age 42.8 years, range 25.3-62.8. Classification of the pharyngeal structures according to Mallampati et al. was done the day before surgery, and grading of visualization of the glottis as described by Cormack and Lehane was done during intubation, with the aim of revealing factors of importance for the possibility of performing tracheal intubation in the prone position.

RESULTS

The large majority of patients classified preoperatively as Mallampati class 1 had Cormack and Lehane grade 1 at laryngoscopy, although some patients had grades 2, 3, and 4. Most problems with intubation in the prone position were anticipated among those classified preoperatively as Mallampati class 3, but tracheal intubation in the prone position was still possible in 21 of the 23 patients in this group. In all, tracheal intubation in the prone position was successful in 244 of the 247 patients (98.8%).

CONCLUSION

Routine tracheal intubation in the prone position can be performed effectively by experienced anaesthesiologists, but this requires continuous training and good support from the anaesthesiology staff.

i-gel™ supraglottic airway in clinical practice: a prospective observational multicentre study

BACKGROUND

The i-gel™ supraglottic airway device has been studied in randomized controlled studies, but it has not been evaluated in a large prospective patient cohort. Therefore, we performed this prospective multicentre observational study to evaluate success rates, airway leak pressure, risk factors for i-gel failure, and adverse events.

METHODS

With Ethics Committee approval and waiver of patients' consent, data about anaesthesia providers, patient characteristics, and the performance of the i-gel were recorded in five independent hospitals in Switzerland over a period of 24 months. We analysed success rates, leak pressures, adverse events, and risk factors for failure.

RESULTS

Data from 2049 i-gel uses were analysed. Patients' mean age was 47 (range 6-91) yr. The primary i-gel success rate without changing size was 93%; the overall success rate was 96%. Insertion was deemed very easy or easy in 92%. The mean airway leak pressure was 26 (8) cm H(2)O. The mean anaesthesia time was 67 (42) min. Risk factors associated with i-gel failure were males (P<0.001), impaired mandibular subluxation (P=0.01), poor dentition (P=0.02), and older age (P<0.01). Adverse events recorded were laryngeal spasms (n=25, 1.2%), blood stained airway devices (n=79, 3.9%), transient nerve damage (n=2, 0.1%), one case of transient vasovagal asystole, and one glottic haematoma.

CONCLUSIONS

The i-gel is a reliable supraglottic airway device failing in <5% and providing high airway leak pressures. Males, impaired mandibular subluxation, poor dentition, and older age are risk factors associated with primary device failure. Serious adverse events are rare.

Effect of head rotation on cerebral blood velocity in the prone position

Background. The prone position is applied to facilitate surgery of the back and to improve oxygenation in the respirator-treated patient. In particular, with positive pressure ventilation the prone position reduces venous return to the heart and in turn cardiac output (CO) with consequences for cerebral blood flow. We tested in healthy subjects the hypothesis that rotating the head in the prone position reduces cerebral blood flow. Methods. Mean arterial blood pressure (MAP), stroke volume (SV), and CO were determined, together with the middle cerebral artery mean blood velocity (MCA V_mean) and jugular vein diameters bilaterally in 22 healthy subjects in the prone position with the head centered, respectively, rotated sideways, with and without positive pressure breathing (10 cmH₂O). Results. The prone position reduced SV (by 5.4 ± 1.5%; P < 0.05) and CO (by 2.3 ± 1.9 %), and slightly increased MAP (from 78 ± 3 to 80 ± 2 mmHg) as well as bilateral jugular vein diameters, leaving MCA V_mean unchanged. Positive pressure breathing in the prone position increased MAP (by 3.6 ± 0.8 mmHg) but further reduced SV and CO (by 9.3 ± 1.3 % and 7.2 ± 2.4 % below baseline) while MCA V_mean was maintained. The head-rotated prone position with positive pressure breathing augmented MAP further (87 ± 2 mmHg) but not CO, narrowed both jugular vein diameters, and reduced MCA V_mean (by 8.6 ± 3.2 %). Conclusion. During positive pressure breathing the prone position with sideways rotated head reduces MCA V_mean ~10% in spite of an elevated MAP. Prone positioning with rotated head affects both CBF and cerebrovenous drainage indicating that optimal brain perfusion requires head centering.

Results of Radiofrequency Ablation of the Small Saphenous Vein in the Supine Position

Objectives: To report the results of a novel approach using supine positioning for radiofrequency ablation (RFA) of the small saphenous vein (SSV) with combined ablation of the great saphenous vein (GSV). Methods: Over a 24-month period, we identified patients with symptomatic SSV incompetence. Access to the SSV was accomplished by ultrasound-guided venipuncture with the patient in the supine position. Results: Small saphenous vein ablation was performed on 27 limbs in 26 patients. Median follow-up was 94 days (interquartile range [IQR] 26, 171). Mean clinical–etiologic–anatomic–pathophysiologic (CEAP) score was 3.5 ± 1.3. Small saphenous vein ablation was performed in conjunction with GSV ablation in 17 patients and with phlebectomy in 14 patients. Postoperative ultrasound was performed after 26 of 27 procedures. The SSV was sealed in all 26 cases. Two patients (8%) had a deep venous thrombosis (DVT). Conclusions: The SSV can be effectively sealed by RFA from the supine position and combined SSV/GSV ablation can be carried out in a single setting.

Tracheal intubation in the prone position with an intubating laryngeal mask airway following posterior spine impaled knife injury

A prone position is not a standard position for anesthesia induction and associated with problems like difficult mask fit, impairment of orotracheal intubation by direct laryngoscopy, and reduction of pulmonary compliance. However anesthetic management of trauma victims presenting with penetrating posterior lumbar spine injury requires airway securement and induction of anesthesia in the prone position to avoid further neurological impairment. We herein present the first reported case of an adult trauma patient presented with an impaled knife protruding out of lower back, who underwent endotracheal intubation with an intubating laryngeal mask airway under general anesthesia in the prone position. Our experience indicates that this technique would be easier and less risky compared to direct laryngoscopy or awake fiber optic intubation and might be considered in an emergency situation.

[Experience with the proseal laryngeal mask in ventriculoperitoneal shunting]

OBJECTIVE

To describe the use, utility, safety, and effectiveness of the Proseal laryngeal mask for airway management in patients undergoing ventriculoperitonea shunting.

PATIENTS AND METHODS

We retrospectively reviewed the records of all patients in whom the Proseal laryngeal mask was used during ventriculoperitoneal shunting between January 2006 and October 2009. Patient demographic characteristics, airway assessments, type of anesthesia, quality of ventilation, and perioperative complications were recorded.

RESULTS

Of the 43 patients included, 8 (18.6%) had at least 1 difficult airway criterion. We were able to insert the Proseal laryngeal mask in all patients. Ventilation was optimal in 39 (91%) patients, with maintenance of end-expiratory carbon dioxide pressures between 35 and 40 mm Hg and airway pressures above 25 cm H2O throughout the procedures. Air leaks developed in 3 cases (7%) when the patient was placed in a lateral-cervical position for surgery; these patients required orotracheal intubation before surgery could begin. Mean duration of surgery was 53 minutes. Awakening occurred without incident in all cases.

CONCLUSIONS

The Proseal laryngeal mask is useful for airway management in patients undergoing ventriculoperitoneal shunting. Due to the forced position of the neck, however, it may be necessary to reposition the mask or even proceed to orotracheal intubation in some cases. As is the case for other advanced uses, experience with the device is necessary. Material for managing a difficult airway should be on hand.

Comparison of the LMA Supreme™ with the LMA Proseal™ for airway management in patients anaesthetized in prone position

BACKGROUND

The laryngeal mask airway (LMA) has been successfully used in patients in the prone position either for rescue or elective airway management. The reusable Proseal™ LMA (PLMA) and the single use Supreme™ LMA (SLMA) have been reported to be suitable for this purpose but few comparative data are available. In this study, we compared the clinical use of both devices in adult patients anaesthetized in the prone position.

METHODS

One hundred and twenty patients undergoing surgery in the prone position were randomized to receive either the PLMA or the SLMA for airway management. Patients positioned themselves in the prone position and after pre-oxygenation, anaesthesia was induced using a target-controlled i.v. infusion of propofol and remifentanil. All PLMAs and SLMAs were inserted by experienced anaesthetists using a guided and a standard technique respectively. Ease of facemask ventilation, time and number of attempts needed for insertion, quality of ventilation, airway seal pressure, fibreoptic view, and complications were compared.

RESULTS

There were no differences between groups in insertion time or first attempt success (100% vs. 98%). The PLMA required fewer manipulations (3% vs. 15%; P=0.02) to achieve effective ventilation and provided a higher seal pressure (mean [sd] 31 [4] vs. 27 [4] cm H2O; P<0.01). The fibrescopic view of the vocal cords was similar, although easier to achieve with the PLMA. The complication rate was low and similar between the groups. Blood was present on masks in 7% vs. 8% and sore throat in 3% vs. 5% of patients with the PLMA and SLMA, respectively.

CONCLUSIONS

Airway management in patients anaesthetized in the prone position was efficient with both devices, although the PLMA required fewer manipulations and achieved a higher seal pressure.

Detection, frequency and prediction of problems in the use of the proseal laryngeal mask airway in children

OBJECTIVES

Our objective was to assess the use of several tests of ProSeal LMA (PLMA) position and function that had been previously published but not studied in the pediatric population in a wide variety of clinical cases.

BACKGROUND

The PLMA is widely used in pediatric anesthesia practice but complication rates have only been studied in small series while tests of function suggested for adults have not been studied at all.

METHODS

We prospectively collected data, after placement of the PLMA by the digital method, on depth of insertion (DOI), 'suprasternal notch' test, 'chest pressure test', leak pressure, maximum minute ventilation (MMV), resting minute ventilation (RMV), success rate of insertion and success rate of passage of a gastric tube. Perioperative complication rates were recorded.

RESULTS

A total of 222 cases were analyzed, 47 were laparoscopic or open abdomen, 15 nonsupine. Ages were 2 months to 20 years and weight 5.4-116 kg. Two hundred seven (91%) were placed successfully at first attempt and 100% at third attempt. One hundred fifty-four of 156 (99%) gastric tubes were placed successfully. Four patients had signs of inadequate ventilation. All of these had MMV/RMV ratios <2. A total of nine had MMV/RMV ratio <2. Eight had DOI score < or =2.

CONCLUSIONS

The PLMA can be used in a large variety of cases with a high degree of success. Clinical tests described for adults, such as MMV/RMV ratio and DOI are also associated with complications in the pediatric population.

Lower intracuff pressure of laryngeal mask airway in the lateral and prone positions compared with that in the supine position

We compared the intracuff pressure (ICP) of a laryngeal mask airway (LMA) in the lateral and prone positions with that in the supine position. One hundred and eight patients, weighing 50-70 kg, scheduled for elective orthopedic and plastic surgery, were assigned to three groups, based on their body position during surgery. General anesthesia was induced and then a size 4 deflated LMA was inserted in each patient in the supine (group 1; n = 42), lateral (group 2; n = 45), or prone position (group 3; n = 21). The LMA cuff was inflated with 15 ml of air. Anesthesia was maintained without nitrous oxide, and the ICP was measured until LMA removal in the supine position. ICP in groups 2 and 3 was significantly lower than that in group 1 from immediately after insertion to the end of surgery. After surgery, turning from the lateral (group 2) or prone (group 3) position to the supine position significantly raised the ICP. Because the ICP is related to the seal pressure of the LMA and postoperative pharyngolaryngeal morbidity, we recommend evaluating and adjusting the ICP appropriately in each body position.