The Pro-Seal laryngeal mask airway

Airway Rescue with the ProSeal™ Laryngeal Mask Airway in the Intensive Care Unit

We report the successful use of the ProSeal™ laryngeal mask airway for airway rescue in a 41-year-old septic patient who could be neither intubated nor facemask ventilated. In principle, the ProSeal™ laryngeal mask airway offers advantages over the Classic LMA in this situation.

The anaesthesiologist in the intensive care unit

PURPOSE OF REVIEW

This review focuses on recent knowledge in areas of anaesthesia expertise which are indispensable to intensive care unit management, including airway management, vascular access, regional analgesia and the treatment of status asthmaticus and status epilepticus.

RECENT FINDINGS

Etomidate as the sole agent for intubation in the intensive care unit has a 90% success rate, while in a prehospital setting, the addition of succinylcholine to etomidate results in a 99% success rate. In determining successful intubation, capnography and laryngoscopic/fibreoptic visualization are superior to auscultation, while auscultation is as effective as the self-inflating bulb or transillumination with the lightwand. The dorsalis pedis artery is an effective alternative to radial artery cannulation, while arterial cannulation itself can result in major adverse effects if complications arise. Ultrasound guidance in the placement of central catheters results in an improved insertion success rate. Internal jugular and subclavian lines have similar risk of haemothorax or pneumothorax, while subclavian lines are associated with the lowest incidence of infection. Midazolam, thiopentone and propofol have all been found to be efficacious in terminating refractory status epilepticus, with thiopentone resulting in a lower incidence of breakthrough seizures or treatment failure but an increased incidence of hypotension. Inhalational anaesthesia using isoflurane or desflurane has also been found to be successful in refractory status epilepticus. In the management of status asthmaticus, limiting minute volume while tolerating hypercapnia and acidosis as well as the use of inhalational anesthesia have proven effective strategies in a number of refractory cases.

SUMMARY

The anaesthesiologist's unique knowledge and skills are ideally suited to the practical management of patients in a critical care setting as well as in the treatment of the critical phases of many illnesses.

Guided Insertion of the ProSeal Laryngeal Mask Airway Is Superior to Conventional Tracheal Intubation by First-Month Anesthesia Residents After Brief Manikin-Only Training

In the following pilot study, we compared conventional laryngoscope-guided tracheal intubation (tracheal intubation) and laryngoscope-guided, gum elastic bougie-guided ProSeal laryngeal mask airway insertion (guided ProSeal) for airway management by first-month anesthesia residents after brief manikin-only training. Five first-month residents with no practical experience of airway management were observed performing these techniques in 200 ASA I-II anesthetized, paralyzed adults. Each resident managed 40 patients, 20 in each group, in random order. The number of insertion attempts, effective airway time, ventilatory capability during pressure-controlled ventilation set at 15 cm H2O, airway trauma, and skill acquisition were studied. Data were collected by unblinded observers. Insertion was more frequently successful (100% versus 65%) and effective airway time was shorter (41 +/- 24 s versus 89 +/- 62 s) in the guided ProSeal group (both P < 0.0001). Expired tidal volume was larger (730 +/- 170 mL versus 560 +/- 140 mL) and end-tidal CO(2) lower (33 +/- 4 mm Hg versus 37 +/- 5 mm Hg) in the guided ProSeal group during pressure controlled ventilation (both P < 0.0001). Blood staining was more frequent on the laryngoscope (24% versus 2%; P < 0.0001) in the tracheal intubation group. There was evidence for skill acquisition in both groups. We conclude that laryngoscope-guided, gum elastic bougie-guided insertion of the ProSeal laryngeal mask airway is superior to conventional laryngoscope-guided tracheal intubation for airway management in terms of insertion success, expired tidal volume, and airway trauma by first-month anesthesia residents after brief manikin-only training. The guided ProSeal technique has potential for cardiopulmonary resuscitation by novices when conventional intubation fails.

Prevention of aspiration under general anesthesia by use of the size 2 1/2 ProSeal laryngeal mask airway in a 6-year-old boy: a case report

We report a case where use of the size 2 1/2 ProSeal laryngeal mask airway helped to prevent pulmonary aspiration of regurgitated gastric fluid. We describe the management of this case and discuss the potential advantages of this modified laryngeal mask airway for supraglottic airway management in pediatric patients.

The ProSeal laryngeal mask airway in children

BACKGROUND

The ProSeal (PLMA) is a new laryngeal mask device with a modified cuff to improve the seal and a drain tube to provide access to the gastrointestinal tract. We assessed the performance of the size 2 (which has no dorsal cuff) and size 3 (which has a dorsal cuff) in terms of insertion success, efficacy of seal, tidal volume, gas exchange, fiberoptic position, gastric tube placement and frequency of problems.

METHODS

Eighty children undergoing minor surgery were studied (n = 40, size 2 PLMA, weight 10-25 kg; n = 40, size 3 PLMA, weight >25-50 kg). Induction was with remifentanil and propofol. Insertion was with the introducer tool and by experienced users. Maintenance was with propofol or sevoflurane and pressure controlled ventilation.

RESULTS

The first-time and overall insertion success rate was 84 and 100%, respectively. Oropharyngeal leak pressure was 31 +/- 5 cmH2O. There were no gastric or drain tube air leaks. Tidal volume and gas exchange was adequate in all patients, other than two brief episodes of hypoxia because of airway reflex activation. The vocal cords and epiglottis were visible in 99 and 80%, respectively, via the airway tube. The first-time and overall insertion success rate for gastric tube insertion was 87 and 100%, respectively. During maintenance, the PLMA was removed in one patient with airway reflex activation and another required epinephrine for bronchospasm. There were no differences in performance between the sizes 2 and 3 PLMA.

CONCLUSION

The PLMA is an effective airway device in children and isolates the glottis from the esophagus when correctly positioned. Despite the lack of a dorsal cuff, the performance of the size 2 was similar to the size 3 PLMA in the age groups tested.

Use of a ProSeal TM laryngeal mask airway for airway maintenance during emergency Caesarean section after failed tracheal intubation

We report the use of the ProSeal laryngeal mask airway to establish and maintain the airway during emergency Caesarean section when tracheal intubation had failed with conventional laryngoscopy and mask ventilation was difficult. The ProSeal laryngeal mask allowed controlled ventilation without gas leak and facilitated drainage of the stomach.

Aspiration of Gastric Contents During Use of a ProSeal??? Laryngeal Mask Airway Secondary to Unidentified Foldover Malposition

The primary function of the drain tube of the ProSeal laryngeal mask airway (PLMA) is to prevent aspiration of regurgitated stomach contents. We report a case of gastric aspiration with the PLMA during a laparoscopic cholecystectomy in a 64-yr-old healthy man secondary to an unidentified foldover malposition. It is imperative that the position and patency of the drain tube be verified in all patients with the PLMA.

IMPLICATIONS

We report a case of gastric aspiration with the ProSeal laryngeal mask during a laparoscopic cholecystectomy secondary to an unidentified foldover malposition. It is imperative that the position and patency of the drain tube be verified in all patients with the ProSeal laryngeal mask.

Use of the ProSeal Laryngeal Mask Airway to initiate ventilation during intensive care and subsequent percutaneous tracheostomy

The ProSeal Laryngeal Mask Airway is a supraglottic airway that aims to provide improved airway seal and separation of the gastrointestinal and respiratory tracts. We report two cases in which the ProSeal Laryngeal Mask Airway was used to initiate controlled ventilation in the intensive care unit and subsequently provide airway maintenance during percutaneous dilational tracheostomy. The first case involved a patient with a known difficult airway who had previously been impossible to intubate conventionally. In both cases, airway management and subsequent tracheostomy were performed without complication.

LMA-Classic and LMA-ProSeal are effective alternatives to endotracheal intubation for gynecologic laparoscopy

PURPOSE

To compare the laryngeal mask airways (LMA), LMA-Classic(TM) (LMA-C) and LMA-ProSeal(TM) (PLMA) with the endotracheal tube (ETT) with respect to pulmonary ventilation and gastric distension during gynecologic laparoscopy.

METHODS

We stratified 209 women, aged > or = 18 yr, ASA physical status I-III, by body mass index as non-obese (< or = 30 kg x m(-2)) or obese (> 30 kg x m(-2)) and randomized them to LMA-C/PLMA or ETT groups for airway management. Anesthesia was induced with propofol, fentanyl and succinylcholine or rocuronium. In the LMA-C/PLMA group we used a size 4 LMA-C in non-obese patients and size 4 or 5 PLMA in obese patients. In the ETT group we used a cuffed 7.0 mm ETT in all patients. Anesthesia was maintained with isoflurane in nitrous oxide and 30-50% oxygen, fentanyl and neuromuscular blockade with mechanical ventilation (tidal volume 10 mL x kg(-1)). The staff surgeon, blinded to the type of airway, scored stomach size on an ordinal scale 0-10 at initial insertion of the laparoscope and immediately before the conclusion of the surgical procedure.

RESULTS

There were no crossovers and no statistically significant differences between LMA-C/PLMA and ETT groups for SpO(2,) P(ET)CO(2) or airway pressure before or during peritoneal insufflation in short (< or = 15 min) or long (> 15 min) periods of peritoneal inflation. Differences between groups with respect to stomach size changes during surgery were not statistically significant.

CONCLUSION

A correctly placed LMA-C or PLMA is as effective as an ETT for positive pressure ventilation without clinically important gastric distension in non-obese and obese patients.

The ProSeal laryngeal mask in myasthenia gravis

This case describes the anaesthesia management of a patient with myasthenia gravis who required mastectomy with axillary lymph node clearance. After withholding medical therapy for the myasthenia preoperatively on the day of surgery, anaesthesia was maintained with halothane, nitrous oxide and a remifentanil infusion. Muscle relaxants were avoided, facilitated by the use of a ProSeal (Intravent, Orthofix, Maidenhead, United Kingdom) laryngeal mask airway for positive pressure ventilation. The ProSeal laryngeal mask airway is a new laryngeal mask device with a modified cuff and a drainage tube which has been shown to have advantages over older designs for use during positive pressure ventilation. The rationale for the management of this patient with myasthenia is discussed.