Michele Carron

Predictors of failure of noninvasive ventilation in patients with severe community-acquired pneumonia

PURPOSE The study aimed to investigate cardiorespiratory parameters potentially predictive of failure of noninvasive ventilation (NIV) in severe community-acquired pneumonia (CAP). PATIENTS AND METHODS Sixty-four consecutive patients with severe CAP entered the study and underwent NIV with a helmet. Arterial blood gases, Pao(2)/FIo(2), and oxygenation index (OI; mean airway pressure × FIo(2) × 100/Pao(2)) were determined before and after a 1-hour trial of NIV. RESULTS Noninvasive ventilation succeeded in 28 patients (43%) and failed in 36 patients (56%). Patients who avoided intubation had significantly (P < .05) shorter stays in ICU and lower rates of mortality in ICU and in hospital. Patients who failed NIV had higher Simplified Acute Physiology Score II at ICU admission (33 ± 11 versus 29 ± 9) and lower pH before NIV trial (7.37 versus 7.44). Furthermore, patients who required intubation failed to improve or worsened arterial blood gases during NIV trial and, by the end of the trial, had lower (P < .05) pH (7.34 versus 7.44) and Pao(2)/FiO(2) (177 versus 228) and higher OI (8.6 versus 5.0) and respiratory rate (28 versus 23 breaths/min). In a multivariate analysis, post-NIV to pre-NIV deltas of Pao(2)/FiO(2) and of OI were independent predictors of NIV failure, with OI delta being significantly more accurate. CONCLUSIONS Noninvasive ventilation failed in approximately half patients with severe CAP. Posttrial to pretrial deltas of Pao(2)/FiO(2) and OI may help to guide decision about endotracheal intubation.

Hemodynamic and Hormonal Stress Responses to Endotracheal Tube and ProSeal Laryngeal Mask Airway ™ for Laparoscopic Gastric Banding.

Background: The stress responses from tracheal intubation are potentially dangerous in patients with higher cardiovascular risk, such as obese patients. The primary outcome objective of this study was to test whether, in comparison with the endotracheal tube (ETT), the Proseal™ Laryngeal Mask Airway (PLMA™) (Laryngeal Mask Airway Company, Jersey, United Kingdom) reduces blood pressure and norepinephrine responses and the amounts of muscle relaxants needed in obese patients. Methods: We assessed hemodynamic and hormonal stress responses, ventilation, and postoperative recovery in 75 morbidly obese patients randomized to receive standardized anesthesia with either an ETT or the PLMA™ for laparoscopic gastric banding. Results: In repeated-measures ANOVA, mean arterial blood pressure and plasma norepinephrine were significantly higher in the ETT group than in the PLMA™ group. In individual pairwise comparisons, blood pressure rose higher in ETT than PLMA™ patients after insertion and removal of airway devices, and after recovery. In ETT compared with PLMA™ patients, plasma norepinephrine was higher after induction of carboperitoneum (mean ± SD, 534 ± 198 and 368 ± 147 and pg/ml, P = 0.001), after airway device removal (578 ± 285 and 329 ± 128 pg/ml, P < 0.0001), and after recovery in postanesthesia care unit (380 ± 167 and 262 ± 95 and pg/ml, P = 0.003). Compared with use of the ETT, the PLMA™ reduced cisatracurium requirement, oxygen desaturation, and time to discharge from both the postanesthesia care unit and the hospital. Conclusions: PLMA™ reduces stress responses and postoperative complaints after laparoscopic gastric banding.

Perioperative noninvasive ventilation in obese patients: a qualitative review and meta-analysis

BACKGROUND Perioperative noninvasive ventilation (NIV) has been proposed to reduce postoperative morbidity and improve perioperative outcomes in patients undergoing general anesthesia. Whether it is advantageous to apply NIV just before and after general anesthesia in obese patients has not been yet established. OBJECTIVES To perform a qualitative review and meta-analysis to assess the effectiveness and tolerability of perioperative NIV in obese patients. METHODS All studies in English language performed in clinical setting that compared the application of NIV with standard care just before and after induction of general anesthesia in obese adults (body mass index [BMI]≥35 kg/m(2)) were included. Data on oxygenation, respiratory function, complications, and outcomes were extracted. RESULTS Twenty-nine articles were selected and used in the qualitative review. Eleven studies including 768 patients were used for subsequent meta-analyses. Compared with standard preoxygenation, NIV was associated with a significant improvement in oxygenation (P<.0001) before tracheal intubation. Benefits in oxygenation (P<.0001), clearance of carbon dioxide (P<.0001), and pulmonary function testing (P<.0001) after general anesthesia were observed with NIV compared with standard care. Postoperatively, NIV was associated with a decreased risk of respiratory complications (relative risk [RR] = .33; 95% confidence interval [CI] .16-.66; P = .002), but not of reintubation after tracheal extubation (RR = .41; 95% CI .09-1.82]; P = .3657) and unplanned intensive care unit admission (RR = .43; 95% CI .16-1.15; P = .0937). NIV-related complications in obese patients were mainly due to intolerance and ranged from 7% to 28% of cases. NIV-related anastomotic leakage and adverse events were not reported. CONCLUSIONS Results from this review and meta-analysis suggest that NIV is well tolerated and effective in improving perioperative care in obese patients. The application of NIV before and after general anesthesia should be considered and promoted in relevant cases.

Bronchoscope-guided intubation through a Laryngeal Mask Airway Supreme in a patient with a difficult-to-manage airway.

We report a case of an obese patient who presented with laryngeal edema and difficult ventilation after failed attempts to intubate. A Laryngeal Mask Airway Supreme (LMA Supreme) reestablished the ventilation and allowed bronchoscope- guided intubation of the trachea. The case suggests that the LMA Supreme may be useful in patients with a difficult airway.

The use of sugammadex in obese patients

To the Editor, We read with great interest the paper by Le Corre et al. on recurarization after reversal of rocuronium-induced neuromuscular block (NMB) with sugammadex. The authors reported a case of respiratory failure in an obese patient requiring sedation and tracheal intubation in the postoperative period. This situation occurred despite initial reversal of NMB to a train-of-four (TOF) ratio [ 0.9 with sugammadex 1.74 mg kg. We congratulate the authors for successful management of this case, and we take this opportunity to underscore an important aspect of the perioperative management of NMB in obese patients. Upper airway obstruction (UAO) in obese patients, which may be caused by the residual effects of the neuromuscular blocking agents (NMBAs), may lead to upper airway collapse and respiratory impairment in the postoperative period. To avoid these complications, a recovery to a TOF ratio C 0.9 at the adductor pollicis muscle is generally recommended. However, there is evidence that upper airway dysfunction and partial UAO may occur in some individuals even with recovery of the TOF ratio to C 0.9. The pharyngeal muscles are particularly susceptible to the residual effects of NMBAs. The impairment of the integrity of the upper airway may put obese individuals at risk for upper airway collapse and increase the risk for postoperative respiratory complications. In our view, the recovery of a TOF ratio of 0.9 should be considered insufficient, particularly in obese patients who have a pharyngeal lumen reduced in size due to peripharyngeal fatty tissue deposition and are at increased risk of UAO. We recommend to wait until a TOF ratio of 1.0 has been attained before proceeding with tracheal extubation in obese patients and to consider this value the goal for an adequate recovery from NMB in this patient population. In our experience, sugammadex now represents the best pharmacological approach to reach the threshold of 1.0 quickly and to reduce the risk of postoperative UAO and its associated morbidity. To achieve this outcome, however, it is necessary to adjust the dose of sugammadex to the level of spontaneous recovery (i.e., 2 mg kg at reappearance of T1-T2) 3,4 and base sugammadex dosing on total body weight, despite some recent evidence of efficacy of doses calculated on ideal body weight. Using the correct use of sugammadex changes the intraoperative management of NMB, but it also reduces the risk of residual paralysis or recurarization in obese patients.

Supreme laryngeal mask airway for laparoscopic cholecystectomy in patient with severe pulmonary fibrosis

Editor—We report the anaesthetic management of a patient with severe pulmonary fibrosis for laparoscopic cholecystectomy using a Supreme laryngeal mask airway (SLMA). A 50-yr-old, 70 kg male was undergoing elective laparoscopic cholecystectomy for acute cholecystitis. The patient had severe pulmonary fibrosis due to occupational (stone and dust) exposure requiring oxygen therapy at home (Fig. 1). An epidural catheter was introduced in the sitting position at T8/9 intervertebral space with the tip of the catheter advanced 3 cm into the epidural space. A test dose with lidocaine 2% (2 ml) was injected through the catheter. The patient was then placed in the supine position and received a dose of levobupivacaine 0.25% (6 ml). Once sensory block to pinprick at T4–L1 was obtained, an infusion of levobupivacaine 0.25% at 4 ml h was administered. After induction of general anaesthesia with propofol 3 mg kg and remifentanil 1 mg kg over 30 s, the patient’s lungs were ventilated using a face mask for 2 min and then a size 4 SLMA was gently positioned at the first attempt. The SLMA cuff was inflated to and maintained at 60 cm H2O. Oropharyngeal leak pressure was 28 cm H2O. A flexible fibreoptic bronchoscope introduced through the SLMA confirmed adequate positioning. Ventilation was set to a 40/60 oxygen/air mixture, peak inspiratory pressure of 22 cm H2O generating an expiratory tidal volume (Vt) of 6 ml kg , ventilatory frequency of 10 bpm, and inspiratory:expiratory ratio of 1:1, without audible air leaks. Anaesthesia was maintained with infusion of propofol 6 mg kgmin and remifentanil 0.15 mg kg min. Neuromuscular block was produced using a single bolus of cisatracurium 0.1 mg kg administered at the beginning of surgical procedure. A 14 G Salem gastric tube was easily passed through the drainage tube of the SLMA. During the surgical procedure, pneumoperitoneum was set at an intra-abdominal pressure of 2 kPa. In order to maintain SpO2 .97% and Vt 6 ml kg 21 during pneumoperitoneum PEEP was increased to 4 cm H2O without audible air leaks. At the end of uneventful surgical procedure, the patient was transferred to the intensive care unit fully awake, free of nausea and pain, and haemodynamically stable with adequate gas exchange. He was discharged from the hospital on the sixth postoperative day. Pulmonary fibrosis is characterized by chronic inflammation of the alveolar wall which tends to destroy the lung architecture by consequent healing with progressively severe fibrosis. This leads to an increase in elastance and resistance of the respiratory system, hypoxaemia, and hypercapnia. Owing to the high risk of respiratory complications, regional block with maintenance of spontaneous ventilation is preferable. 2 Laparoscopic cholecystectomy was successfully performed under regional anaesthesia in some patients. 2 However, general anaesthesia remains the best choice to prevent pulmonary aspiration and respiratory embarrassment secondary to pneumoperitoneum. In patients with pulmonary fibrosis, lung protective ventilation is required to obtain the best oxygenation and avoid the risk of barotrauma and lung damage. 4 The laryngeal mask airway (LMA) seems to have advantages over the tracheal tube to reduce respiratory system resistance, 6 and the effectiveness of mechanical ventilation through LMA may be increased by the recourse to pressure-controlled ventilation. Moreover, Proseal LMA (PLMA) resulted in smoother emergence from anaesthesia and in lower frequency of postoperative nausea, vomiting, airway morbidity, and analgesic requirements than the tracheal tube. SLMA is a new, single-use, latex-free, LMA with gastric access that combines the desirable features of the Fastrach, Proseal, and Unique LMA devices that may be easily inserted without placing fingers in the patient’s mouth or that do not require an introducer tool for insertion and offers glottic seal pressures similar to the PLMA. Despite the fact that PLMA may be an effective alternative to tracheal VC (%)

Sugammadex for reversal of neuromuscular blockade: a retrospective analysis of clinical outcomes and cost-effectiveness in a single center.

Objective The aim of the study is to evaluate the clinical and economic impact of introducing a rocuronium–neostigmine–sugammadex strategy into a cisatracurium–neostigmine regimen for neuromuscular block (NMB) management. Methods We conducted a retrospective analysis of clinical outcomes and cost-effectiveness in five operating rooms at University Hospital of Padova. A clinical outcome evaluation after sugammadex administration as first-choice reversal drug in selected patients (rocuronium–sugammadex) and as rescue therapy after neostigmine reversal (rocuronium–neostigmine–sugammadex) compared to control was performed. A cost-analysis of NMB management accompanying the introduction of a rocuronium–neostigmine–sugammadex strategy into a cisatracurium–neostigmine regimen was carried out. To such purpose, two periods were compared: 2011–2012, without sugammadex available; 2013–2014, with sugammadex available. A subsequent analysis was performed to evaluate if sugammadex replacing neostigmine as first choice reversal drug is cost-effective. Results The introduction of a rocuronium–neostigmine–sugammadex strategy into a cisatracurium–neostigmine regimen reduced the average cost of NMB management by 36%, from €20.8/case to €13.3/case. Patients receiving sugammadex as a first-choice reversal drug (3%) exhibited significantly better train-of-four ratios at extubation (P<0.001) and were discharged to the surgical ward (P<0.001) more rapidly than controls. The cost-saving of sugammadex as first-choice reversal drug has been estimated to be €2.9/case. Patients receiving sugammadex as rescue therapy after neostigmine reversal (3.2%) showed no difference in time to discharge to the surgical ward (P=0.44) compared to controls. No unplanned intensive care unit (ICU) admissions with rocuronium–neostigmine–sugammadex strategy were observed. The potential economic benefit in avoiding postoperative residual curarization (PORC)-related ICU admission in the 2013–2014 period was estimated at an average value of €13,548 (€9,316–€23,845). Conclusion Sugammadex eliminated PORC and associated morbidities. In our center, sugammadex reduced the costs of NMB management and promoted rapid turnover of patients in operating rooms, with total cost-effectiveness that counteracts the disadvantages of its high cost.

Comparison of invasive and noninvasive positive pressure ventilation delivered by means of a helmet for weaning of patients from mechanical ventilation

PURPOSE The effectiveness of noninvasive positive pressure ventilation delivered by helmet (H-NPPV) as a weaning approach in patients with acute respiratory failure is unclear. PATIENTS AND METHODS We randomly and evenly assigned 64 patients intubated for acute respiratory failure to conventional weaning with invasive mechanical ventilation (IMV) or H-NPPV. The primary end point was a reduction in IMV duration by 6 days between the 2 groups. Secondary end points were the occurrence of ventilator-associated pneumonia and major complications, duration of mechanical ventilation and weaning, intensive care unit and hospital length of stay, and survival. RESULTS The mean duration of IMV was significantly reduced in the H-NPPV group compared with the IMV group (P<.0001), without significant difference in duration of weaning (P=.26) and total ventilatory support (P=.45). In the H-NPPV group, the incidence of major complications was less than the IMV group (P=.032). Compared with the H-NPPV group, the IMV group was associated with a greater incidence of VAP (P=.018) and an increased risk of nosocomial pneumonia (P=.049). The mortality rate was similar between the groups, with no significant difference in overall intensive care unit (P=.47) or hospital length of stay (P=.37). CONCLUSIONS H-NPPV was well tolerated and effective in patients who were difficult to wean.

Sugammadex after the Reappearance of Four Twitches during Train-of-four Stimulation: Monitoring and Dose Considerations

508 February 2014 In Reply: In his letter to the Editor, Dr. Carron raises two important issues referring to the published data by Pongrácz et al.1 evaluating low doses of sugammadex to reverse rocuroniuminduced neuromuscular blockade (NMB) after the reappearance of four twitches during train-of-four (TOF) stimulation. First, Dr. Carron emphasizes the importance of having considered a TOF fade ratio of 1.0 or greater as an adequate reversal in our study, unlike 0.9 or greater used by other investigators. Indeed, to date in all published studies investigating sugammadex, the primary outcome parameter was a nonnormalized TOF ratio of 0.9. However, a recorded TOF fade ratio of 0.9 does not equal full recovery of the NMB, because after sugammadex the TOF ratios regularly reach a final value of 1.0 or greater. Therefore, we considered a To the Editor: I read with great interest the article by Pongrácz et al.1 evaluating the appropriate dose of sugammadex to reverse neuromuscular blockade (NMB) after the reappearance of four twitches during train-of-four (TOF) stimulation. It is a welcome addition to previous studies that have demonstrated the superiority of sugammadex over anticholinesterases in completely, safely, and quickly reversing rocuroniuminduced NMB of any magnitude.1,2 This study raises two important issues, which deserve comment. To my knowledge, this is the first clinical trial that has considered a TOF ratio of 1.0, instead of 0.9 or greater, as the goal for reversal of NMB.1 A TOF ratio of 0.9 or greater may not indicate full recovery, as this ratio can be associated with impaired neuromuscular transmission,3 inhibition of the hypoxic–ventilatory response, and upper airway or pharyngeal dysfunction.4 Acceleromyography studies have confirmed the potential for inadequate reversal at a TOF ratio of 0.9 or greater, leading to the recommendation that a TOF ratio of 1.0 or greater be used to confirm complete recovery from NMB.2,4 With the introduction of sugammadex into clinical practice, obtaining a TOF ratio of 1.0 or greater is now a relatively easy goal to achieve, and it is hoped that future research and clinical practice will follow the example shown by Pongrácz et al.1 by insisting on the use of this ratio as the goal for NMB reversal. Although Pongrácz et al.1 found that 1.0 mg/kg was sufficient to achieve a TOF of 1.0 after the reappearance of four twitches on TOF stimulation, I have some concern to recommend it as the optimal dose of sugammadex in this situation. A dose of sugammadex is just sufficient to liberate approximately 30% of the postjunctional nicotinic receptors, a condition necessary for the complete reversal.5 So, even with complete reversal of NMB by sugammadex, up to 70% of the postjunctional nicotinic receptors may remain occupied by steroidal neuromuscular-blocking agent.5 Therefore, a larger dose of sugammadex, such as 2 mg/kg, may be more appropriate, as it will create a greater rocuronium tissue to plasma concentration gradient, thereby causing more free rocuronium molecules to move into the circulation, where they are promptly encapsulated.5 Reducing the number of postjunctional nicotinic receptors occupied by rocuronium may reduce the risk of recurarization6 and the neuromuscular-blocking effects of agents that decrease acetylcholine release,5 thus further improving patient safety.4–6 With its unique mechanism of action, proven efficacy in reversing NMB, fast onset of action, and minimal adverse effects, sugammadex has become an important tool in modern-day anesthesia practice.2,4,5 By using a TOF ratio of 1.0 or greater as the goal for NMB reversal and administering the most appropriate dose for the degree of blockade, full potential of sugammadex for improving patient care and safety may be achieved.

Anesthesia for urgent sequential ventriculoperitoneal shunt revision and cesarean delivery

Many women with cerebrospinal shunts are now reaching the childbearing age and may face risks from shunt malfunction during pregnancy. We report on a case of a 35-year-old primigravida at 36 weeks of gestation who was admitted to our hospital because of headache and cognitive and visual disturbances. At 13 years of age the patient had had a ventriculoperitoneal shunt for hydrocephalus related to an aqueduct stenosis. A computerized tomography scan of the brain showed moderate ventricular dilatation likely resulting from a malfunctioning shunt. On the second day after admission her level of consciousness and neurologic condition suddenly worsened and a second brain scan showed further enlargement of the ventricular system. After multidisciplinary consultation, it was decided to proceed with urgent sequential shunt revision and cesarean delivery. Anesthetic considerations included the risk of difficult airway, rising intracranial pressure and conflicting demands between neurological and obstetrical procedures (such as deep versus low-dose anesthesia). General anesthesia was provided with an oxygen/air mixture (50/50%), i.v. fentanyl (5 microg/kg total dose) and i.v. propofol infusion (4-6 mg kg(-1) h(-1)). Surgical procedures were carried out without complications and both mother and infant were doing well at a 6-month follow-up. An interdisciplinary approach allowed two urgent sequential operations to be performed with a unique anesthetic regimen and excellent maternal and fetal outcome.