Pencil-point needle bevel direction influences ED50 of isobaric ropivacaine with fentanyl in spinal anesthesia for cesarean delivery: a prospective, double-blind sequential allocation study

BACKGROUND

There is little evidence on the influence of bevel direction of a pencil-point needle on the median effective dose (ED50) of isobaric ropivacaine and fentanyl in spinal anesthesia for cesarean delivery.

METHODS

In this prospective, double-blind, sequential allocation study, 82 parturients scheduled for elective cesarean delivery under combined spinal-epidural anesthesia were included. We sought to determine the median effective dose of intrathecal 0.75% isobaric ropivacaine plus fentanyl 15μg with two different bevel directions of a 26-gauge Whitacre needle using up-down sequential allocation. Parturients were randomly allocated to either Group Ce (needle aperture oriented in a cephalad direction) or Group Ca (aperture directed caudally). The initial dose was 0.75% ropivacaine 11.25mg plus fentanyl 15μg in both groups. Each dose was classified as effective if, after 15min and during the next 60min, there was inability to appreciate pin-prick as sharp at T4, a visual analogue pain score <2 and no requirement for an epidural rescue bolus.

RESULTS

Eighty patients were included in the analysis. The ED50 in group Ca was significantly higher (13.09mg, 95% CI 12.19-14.00) than in group Ce (10.10mg, 95% CI 9.54-10.65, P <0.001).

CONCLUSION

The orientation of the distal aperture of a 26-gauge Whitacre needle during induction of spinal anesthesia for cesarean delivery influences the ED50 of 0.75% ropivacaine.

Influence of LMA cuff pressure on the incidence of pharyngolaryngeal adverse effects and evaluation of the use of manometry during different ventilation modes: a randomized clinical trial

BACKGROUND

Pharyngolaryngeal discomfort is a significant complication following the use of laryngeal mask airway (LMA). The present study aimed to investigate the relation of LMA cuff pressure and the occurrence of pharyngolaryngeal discomfort during spontaneous ventilation (SV), pressure support (PSV) and pressure control ventilation (PCV).

METHODS

A hundred and twenty patients, ASA I-III, were included in this study. Originally the patients were divided into three groups: the 1st group was left to breath spontaneously, the 2nd group was placed under PSV while PCV was used in the 3rd group. Each group was divided into two subgroups: A) intervention group (maintaining cuff pressure at 60 cmH2O, measurement in 10 min intervals) and B) observation group (no intervention in cuff pressure, measurement in 10 min intervals). Anesthesia was induced with propofol and fentanyl and maintained with sevoflurane in air/oxygen. Patients were assessed 2 and 24 hours post-surgery, for sore throat, dysphonia or dysphagia.

RESULTS

A and B subgroup comparison at 24 hours revealed a statistically significant difference in the presence of pharyngolaryngeal discomfort in the PSV group (10% versus 55% respectively, P=0.006). Furthermore, when assessing the effect of maintaining a constant cuff pressure regardless of mode of ventilation, significantly fewer adverse effects were observed (8.3% vs. 35%, P=0.001) when compared to the non-intervention subgroup.

CONCLUSION

Maintaining LMA cuff pressure in values which do not exceed 60 cmH2O probably contributes in decreasing pharyngolaryngeal discomfort independently of ventilation mode. The ventilation mode which leads to the highest incidence of pharyngolaryngeal morbidity when cuff pressures are not closely monitored is PSV.

First experience of the use of the C-MAC PM videolaryngoscope in a clinical setting by anesthetic nurses: a comparison with anesthetists

BACKGROUND

The Storz C-MAC videolaryngoscope has been found to facilitate endotracheal intubation and to be easy to use by novice users. However, it has never been studied in those who will probably use it most, anesthetists and anesthetic nurses. The aim of the present study was to identify the number of attempts needed before the participants were able to intubate 2 consecutive patients within 30 seconds.

METHODS

Following a didactic session, 22 anesthetists and 21 anesthetic nurses were included in the study and attempted to intubate 184 patients with predicted easy laryngoscopy scheduled to undergo elective surgery. The number of attempts before achieving 2 consecutive successful intubations and time to intubation were recorded for both groups of participants. Perception of ease of use for the device was also recorded.

RESULTS

Overall, anesthetic nurses required more attempts before achieving 2 consecutive successful intubations (5.9 +/- 3.24 vs 2.73+/- 1.67, p < 0.0005). They also had significantly more failures until 2 consecutive successful intubations were achieved, compared to anesthetists (4.1 +/- 2.8 vs 1.32 +/- 1.25, p < 0.0005). A significantly higher percentage of anesthetic nurses required more than 3 attempts before achieving 2 consecutive intubations (75% vs 36%, p = 0.016). Regarding the intubation time, no significant differences were recorded between specialties. Anesthetic nurses assessed the C-MAC as easier to use than anesthetists did.

CONCLUSIONS

This is the first clinical study assessing the use of the C-MAC videolaryngoscope by inexperienced anesthetists and anesthetic nurses indicating that it is easy to learn and to use in their hands.

Quality of life and pre-operative anxiety level in patients scheduled to undergo thoracic surgery

PURPOSE

Increased preoperative anxiety levels may lead to adverse outcomes. We aimed at assessing the relationship between quality of life (QoL) and preoperative anxiety level during the 4-week preoperative period in patients scheduled to undergo thoracic surgery and we tried to identify patients who could benefit from preoperative supportive measures.

METHODS

One hundred patients comprised the study population (52 men and 48 women) out of the initial 136, who were scheduled to undergo thoracic surgery. Mean age was 56±15 years (±SD). After obtaining informed consent, participants were asked to answer a questionnaire, through a personal interview, 12 to 15 h prior to their scheduled thoracic operation. The questionnaire included questions on demographics and incorporated the State Anxiety Inventory (STAI) and SF-36 scales.

RESULTS

Female patients (p=0.023), unemployed patients (p=0.01) and patients that were scheduled for a mediastinoscopy (p=0.001) experienced increased anxiety level. Lower scores in several parameters related to the QoL were found to be associated with increased anxiety level. Limitations in patients' ability to work or to perform other everyday activities as a result of mental health problems (p=0.006), low vitality (p<0.001), bad general mood (p<0.001), deteriorated general health (p<0.001) and general mental health (p<0.001) were associated with preoperative anxiety. No differences were found in anxiety level among lung cancer and non-lung cancer patients.

CONCLUSION

This study showed an inverse proportional correlation between preoperative QoL and anxiety during the 4-week period prior to thoracic surgery. Appropriate pharmaceutical and psychological support may improve patients' anxiety level.

Macintosh and Glidescope® performance by Advanced Cardiac Life Support providers: a manikin study

BACKGROUND

The aim of the present study was to assess whether the use of the Glidescope® would improve the success rates and the duration of intubation attempts during airway management when compared to direct laryngoscopy in Advanced Cardiac Life Support (ACLS) providers with no prior experience in videolaryngoscopy.

METHODS

This cross-over randomized study involved 44 ACLS providers. The educational session for the participants included a brief presentation of the equipment and a demonstration of the Glidescope®. All intubations were performed using a 7.5-mm endotracheal tube on an adult manikin. A size 3 Macintosh blade and a standard Glidescope® adult blade were used. Glidescope® videolaryngoscope was used. The primary endpoints were: duration of each endotracheal intubation attempt and success rate for each device. A secondary endpoint was the perception of ease of use with each device. Each participant was asked to assess the ease of use of each device using a visual analogue scale (0=extremely difficult and 10=extremely easy).

RESULTS

No statistically significant difference was observed in the time required to successful intubation of the trachea with the Macintosh laryngoscope and the Glidescope®. However, significantly fewer intubation attempts were required with the Glidescope® compared to the Macintosh laryngoscope. In addition, most candidates found that using the videolaryngoscope was easy.

CONCLUSION

This study demonstrated that the Glidescope® videolaryngoscopy performed at least as well as conventional laryngoscopy in ACLS providers. Although simpler ventilation techniques should be applied first during critical airway management, this study suggests that, when intubation is needed, videolaryngoscopy cna be helpful.