Manoj Kumar Upadhyay 1 , Geetesh Kumar 2 , Ajay Chaurasia 2 , Deepak Narang 3*
Author affiliations:
Abstract
Introduction: Endotracheal Intubation (ETI) is highest quality level for airway organization. LMA ProSeal™ (PLMA) insertion utilizing Gum Elastic Bougie (GEB) guidance, which has got 100% first attempt success rate, also requires laryngoscopy, hence nullifying its advantage of being a supraglottic airway device. We aimed to compare the hemodynamic responses associated with laryngoscopy assisted GEB guided PLMA placement with that of conventional endotracheal intubation.
Method: Hundred normotensive ASA1 or 2 patients of either sex (age 18 to 40yrs) undergoing general anesthesia for elective surgery included and evaluated for pressor response. Following a uniform premedication and standard anesthesia technique (thiopentone + vecuronium), either of airway was placed and pulse rate, (beats/min); Mean blood pressure, MAP (mmHg) (at Tb = base line, T0 = just before laryngoscopy and PLMA/ETT placement, T1 = 1min, T3 = 3min, T5 = 5 min, T7 = 7 min after placement).
Results: Patients demographics between the PLMA and ETT groups were similar. Following laryngoscopy and PLMA\ETT placement, both were associated with statistically significant increase in HR and MAP with respect to its basal value. Although it was less marked in case of PLMA Group, when comparison was made within individual Group. Duration of laryngoscopy and time of placement were longer in PLMA Group as compared to ETT Group (35.71 and 12.69 sec. vs 21.30 and 10.76 sec. respectively). ETT insertion was related with higher incidence of cough (p < 0.05), but similar for sore throat and hoarseness (p > 0.05).
Conclusion: Hence GEB guided PLMA method must be used as a reinforcement method in cases where standard insertion methods fall ineffective and in ineffectual tracheal intubation where the bougie is incidentally embedded into throat and quick control of the airway route is essential.
Key words: Gum elastic bougie; Laryngeal Mask Airway; Hemodynamics; Pressor response
Abbreviations: LMA – laryngeal mask airway; ETI – Endotracheal Intubation; GEB – Gum Elastic Bougie; ETT –Endotracheal tube; PLMA – Laryngeal Mask Airway ProSeal
Citation: Upadhyay MK, Kumar G, Chaurasia A, Narang D. Evaluation of gum elastic bougie guided Proseal laryngeal mask airway insertion technique. Anaesth. pain intensive care 2021;25(3):338–344. DOI: 10.35975/apic.v25i3.1531
Received: March 20, 2021; Reviewed: April 11, 2021; Accepted: May 11, 2021
Introduction
The laryngeal mask airway (LMA) is a supraglottic airway route tool, presented by Dr. Archie Brain in 1983. It fills the hole in airway route between tracheal intubation and utilization of the face mask. The main benefit of LMA over endotracheal tube (ETT) is that it avoids the use of laryngoscope to visualize and penetrate the laryngeal opening and hence produces less hemodynamic changes.1, 2
In the year 2000 a new version of LMA was introduced by the manufacturer named LMA ProSeal™ (PLMA), which incorporates another tube to allow second seal against upper esophageal sphincter giving continuity with the alimentary tract and isolating it from the airway.3 PLMA can achieve an additional effectual seal and facilitates gastrointestinal tube positioning without an expansion in straightforwardly estimated mucosal pressure.4,5
PLMA route is intended to be embedded utilizing either forefinger or introducer tool (IT) as described by the manufacturer.6 However, another new method of insertion has recently been described which involves the use of gum elastic bougie (GEB). The drain tube of PLMA is primed with bougie whose distal end is placed in the esophagus under laryngoscopic guidance. Then the PLMA is inserted digitally along palatopharyngeal curve and bougie removed.7 The authors claimed that GEB guided inclusion of PLMA has a higher first endeavor achievement rate as analyzed to other methods (GEB, 100%; digital 88%; IT 84%)8 and is linked with slight hemodynamic changes and a less prevalence of injury.7 The main cause of insertion difficulty with older techniques is disorder of PLMA sleeve on rear of the mouth and incompetent of the distal sleeve to arrive at the hypopharynx which is overcome by GEB guided technique.9
Laryngoscopy has been implicated as the main culprit for increase in pressor response due to stimulation of base of the tongue induced by the tip of its blade lifting the epiglottis.7 The most significant factor affecting the cardiovascular reaction is interval for laryngoscopy and powers applied during it.8,9
Hence this seems likely that laryngoscopic assisted PLMA placement with GEB guided technique might also have increased pressor response thus nullifying its advantage of being a supraglottic device. Keeping this in mind, it was proposed to study the difference in pressor responses with this technique of insertion of PLMA as against conventional placement of ETT which also requires laryngoscopy.
Methodology
100 normotensive patients of either sex having a place with ASA I or II, between 20-40 y old, booked to go through elective medical procedure, requiring general sedation were incorporated.
Patient with a known or anticipated complicated airway, mouth starting < 2.5 cm, Body mass index > 35 kg/m, any patient with a history of regurgitation, known case of hypertension and ischemic heart disease.
In this forthcoming randomized preliminary, every one of the patients were inspected during the preoperative visit a day prior to surgery. Insights about the patient's clinical history, physical assessment, Mallampati score, mouth opening, and basic routine investigations were recorded. Notified consent was taken for patient's involvement in the examination. Each patient was continued fasting for six hours before booked season of a medical procedure and premedicated with tablet alprazolam 0.25 mg and tablet ranitidine 150 mg orally at bedtime and at two hours preoperatively. On arrival of the patient in the operating room, non-invasive blood pressure (NIBP), ECG and pulse oximetry were recorded using Siemens SC 5000 monitor. Basal readings of systolic (SBP) and Diastolic Blood Pressure (DBP), Heart Rate (HR) and arterial saturation of oxygen (SpO2) on air were noted. An intravenous line was started. Patients were then randomly assigned to either Group PLMA (n = 50) or Group ETT (n = 50).
Patient's head was placed on a 7 cm tall pad of and neck was flexed and head extended i.e. the standard sniffing position for intubation. After induction using sleep dose of thiopentone 4-6 mg/kg followed by 0.1 mg/kg vecuronium bromide patients were ventilated for 2 min via face mask using Bain’s breathing system.
For patients in PLMA Group, a well lubricated PLMA loaded with GEB with fully deflated cuff, size 3 for females or size 4 for males, was introduced using standard midline approach i.e., positioned the GEB 5-10 cm into the throat under direct laryngoscopic direction, advanced the PLMA against palatopharyngeal curve utilizing digital guidance when an associate held the curved end of bougie, withdrawing the bougie while holding the PLMA in position. Then the cuff was inflated with sufficient air to keep cuff pressure around 60 cmH2O. The correct placement of PLMA was judged clinically by the capacity to ventilate the patient without substantial leak at an air pressure of < 20 cmH2O and by auscultation of breath sounds.
.
.
For Group ETT patients, an appropriate size cuffed
ETT (size 7.0 mm / 7.5 mm ID for females and size 8.0 mm / 8.5 mm ID for males) was inserted using standard technique for intubation.
General anesthesia in both groups was administered with 0.5% halothane and 67% nitrous oxide in O2. Heart rate (HR), SBP, DNP, MAP and SpO2 were recorded at following time intervals;
Tb – Basal i.e. before start of induction of anesthesia
T0 – Just before PLMA or ETT insertion but after administration of thiopentone and vecuronium bromide
T1 – One minute after successful placement of PLMA/ETT
T3 – Three minutes after successful placement of PLMA/ETT
T5 – Five minutes after successful placement of PLMA/ETT
T7 – Seven minutes after successful placement of PLMA/ETT
Number of attempts, duration of laryngoscopy and time required for the proper placement of PLMA/ETT were recorded. Time required for successful placement was measured from the start of laryngoscopy to the confirmation of proper placement.
At the end of a surgical procedure, neuromuscular block was reversed with atropine 0.02 mg/kg and neostigmine 0.05 mg/kg. Any postoperative complexities like cough, sore throat, hoarseness of voice was noted.
Statistical Analysis: Parameters collected were compiled and analyzed utilizing matched and unmatched ‘t’ test, chi-square test and Fisher precise analysis. Data is presented as Mean ± SD or n (%).
Results
Demographic data of the patients are compared in Table 1. The differences were statistically not significant.
The comparative duration of laryngoscopy and time taken to successful placement of airway device in two groups is presented in Table 2. The difference was statistically highly significant (p < 0.001).
In Table 3 mean heart rates in both of the groups at all specified time interval is comparable except at one minute after airway insertion when the rise in the heart rate in Group B was significantly more than Group A.
The baseline (TB) systolic blood pressure (SBP) as well as blood pressure just before airway placement but after induction i.e (T0) were statistically equivalent in two groups (p > 0.05). However, at one minute and at 3 min after ETT/PLMA placement (T1) the rise in SBP was greater in Group B as compared to Group A (p < 0.001). The variation in rise in SBP in both the groups remained statistically significant till T3, after which it returned to near base line values (T5) or even low (T7) (Table 3).
.
.
The diastolic blood pressures (DBP) were statistically comparable in two groups (p > 0.05) at TB, T0 and at T7 (p > 0.05). However, following airway placement at T1 there was a greater rise in DBP in Group B as compared to Group A (p < 0.001). The difference in both groups remained statistically significant till T5 which ultimately touched base line at T7 (i.e. 7 min after airway placement) (p > 0.05) (Table 3).
MAP at baseline (TB) as well as just before airway placement (T0) were statistically comparable in two groups (p > 0.05). At T1 and T3 MAP registered a significant rise which was more marked in Group B.
At 5 and 7 min after airway placement (T5 and T7) MAP returned to near baseline reading in both groups, which was statistically not significant (p > 0.05) (Table 3).
As shown in Table 4, the frequency of cough was higher in Group B as compared to Group A, which was statistically significtant (p < 0.05). On the other hand, occurrence of sore throat and hoarseness did not achieve statistical significance (p > 0.05) at airway removal in both groups.
Discussion
In our study in Group A patients, PLMA was used as an airway device which was introduced using GEB technique following laryngoscopy.7 In Group B patients, ETT was introduced using conventional technique. Pressor reactions as a rise in HR, SBP, DBP and MAP were recorded and compared using chi-square, paired and unpaired ‘t’ tests.
Pressor response is a common occurrence following laryngoscopy and tracheal intubation due to sympathoadrenal response in the form of a rise in catecholamine concentration.7 Shribman et al. suggested that the main reason of sympathoadrenal response to tracheal intubation is the stimulation of upper airways by laryngoscope. He added that the introduction of tracheal tube through the vocal cords and inflating a cuff in the infraglottic area donate small added inspiration.10
To avoid pressor response to laryngoscopy, supraglottic devices have been introduced in anaesthesia practice which do not require laryngoscopy for their placement. One such device is PLMA, which has been used in this study.
Conventionally PLMA is placed using either index finger or introducer tool technique. However, Hawath et al. reported that the GEB aided placement of PLMA under laryngoscopic guidance is better than index finger or introducer tool technique. They suggested that GEB guides the tip of PLMA towards the hypopharynx and prevents its impaction at the back of the pharynx.11 He evaluated this new technique and concluded that it is associated with no difference in heart rate or blood pressure.7
In our study, however, laryngoscopic assisted GEB guided placement of PLMA was associated with considerable rise in MAP and HR. This difference might be because of differences in the method of induction in the two studies. While we used sleep dose of thiopentone and vecuronium bromide for induction of anesthesia in our patients, Howath et al. used midazolam, fentanyl and propofol. Midazolam and fentanyl used in their study are known to modulate the pressor response of laryngoscopy. Also use of propofol for induction of anesthesia is known to achieve greater fall in blood pressure in comparison with the use of thiopentone alone. Moreover, they also used lack of response to jaw thrust as an end point of induction, unlike our study where we used loss of eye lash reflex for the same. It is a known fact that lack of response to jaw thrust requires deeper planes of anesthesia as compared to loss of eyelash reflex which might explain milder pressor response in their study. This interpretation is in compliance with the analysis conducted by Yakaittis et al. which concluded that greater depth of anesthesia abolishes the tracheal and carinal reflexes which are responsible for the pressor response.12
In our study, the time duration of laryngoscopy and time of placement of PLMA/ETT were remarkably elevated in PLMA as compared to ETT Group (12.69 and 35.71 sec. vs 10.76 and 21.30 sec.) respectively. It is well known that hemodynamic response to laryngoscopy is proportional to the duration of laryngoscopy.13
In our study, basal hemodynamic values were equivalent in both the category. Following laryngoscopy and PLMA/ETT placement BP and HR elevated pointedly in both the groups. The rise in BP and HR following PMLA placement was significantly less marked than tracheal intubation (p < 0.05). Hence, it is evident from the above observations that, although duration of laryngoscopy was more in PLMA Group, pressor response was more in ETT Group. This interpretation is in compliance with the study conducted by Hassan et al. which states that laryngoscopy stimulates the proprioceptors at the base of tongue leading to stimulus reliant increase of pressor response and catecholamine concentration and subsequent orotracheal intubation recruits additional receptors that augment the hemodynamic and catecholamine responses to laryngoscopy.13
Our study is also in agreement to an evaluation carried out by Ganzouri et al. who compared the pressor responses of PLMA using index finger/introducer tool technique with those of endotracheal intubation. They concluded that endotracheal intubation is associated with significant pressor response, while it is minimal with the use of PLMA with standard technique.14 Similarly, Evan et al., while evaluating PLMA using index finger/introducer tool technique, observed minimal hemodynamic response to its insertion in their patients. On the other hand, laryngoscopic assisted PLMA guided placement of PLMA in our study was associated with significant pressor response.15 Two reasons can be elicited for this discrepancy of observation. One obvious reason is that we used laryngoscopic assisted GEB guided technique for PLMA placement, while Evan et al. used conventional index finger or introducer tool technique. Another reason is difference in method of induction in two studies. While we used sleep dose of thiopentone and vecuronium bromide for induction, Evan et al. also used fentanyl and propofol for induction of anesthesia in their study.
Braun et al. reported that using the standard technique, hemodynamic responses to PLMA insertion and classic LMA insertion were similar,16 Jung et al., while evaluating LMA in children, reported that when insertion of classic LMA using laryngoscopic guidance is associated with greater hemodynamic response as compared to, when inserted using index finger technique.17
It can be postulated from our study that laryngoscopy assisted GEB guided placement of PLMA is associated with pressor response, which is although lesser then laryngoscopy followed by intubation, but greater than PLMA when inserted using standard technique.
Conclusion
This study suggests that GEB primed laryngeal mask airway Proseal™ when placed under laryngoscopic guidance, is associated with pressor response in the form of an increase in pulse rate and blood pressure. However, this pressor reaction is of lesser magnitude and lasts for lesser duration as compared to laryngoscopy and intubation.
Conflict of interest
None declared by the authors.
Authors’ contribution
MKU: Conceived and designed the analysis, collected the data
GK: Collected the data, contributed data analysis tools
AC: Performed the analysis; manuscript writing
DN: Data analysis, literature search, reference search, manuscript editing
References
.
Author affiliations:
- Professor, Department of Anesthesiology and Critical Care, NC Medical College, Israna, Panipat, Haryana, India.
- Assistant Professor, Department of Anesthesiology and Critical Care, NC Medical College, Israna, Panipat, Haryana, India.
- Associate Professor, Department of Anesthesiology and Critical Care, NC Medical College, Israna, Panipat, Haryana, India.
Abstract
Introduction: Endotracheal Intubation (ETI) is highest quality level for airway organization. LMA ProSeal™ (PLMA) insertion utilizing Gum Elastic Bougie (GEB) guidance, which has got 100% first attempt success rate, also requires laryngoscopy, hence nullifying its advantage of being a supraglottic airway device. We aimed to compare the hemodynamic responses associated with laryngoscopy assisted GEB guided PLMA placement with that of conventional endotracheal intubation.
Method: Hundred normotensive ASA1 or 2 patients of either sex (age 18 to 40yrs) undergoing general anesthesia for elective surgery included and evaluated for pressor response. Following a uniform premedication and standard anesthesia technique (thiopentone + vecuronium), either of airway was placed and pulse rate, (beats/min); Mean blood pressure, MAP (mmHg) (at Tb = base line, T0 = just before laryngoscopy and PLMA/ETT placement, T1 = 1min, T3 = 3min, T5 = 5 min, T7 = 7 min after placement).
Results: Patients demographics between the PLMA and ETT groups were similar. Following laryngoscopy and PLMA\ETT placement, both were associated with statistically significant increase in HR and MAP with respect to its basal value. Although it was less marked in case of PLMA Group, when comparison was made within individual Group. Duration of laryngoscopy and time of placement were longer in PLMA Group as compared to ETT Group (35.71 and 12.69 sec. vs 21.30 and 10.76 sec. respectively). ETT insertion was related with higher incidence of cough (p < 0.05), but similar for sore throat and hoarseness (p > 0.05).
Conclusion: Hence GEB guided PLMA method must be used as a reinforcement method in cases where standard insertion methods fall ineffective and in ineffectual tracheal intubation where the bougie is incidentally embedded into throat and quick control of the airway route is essential.
Key words: Gum elastic bougie; Laryngeal Mask Airway; Hemodynamics; Pressor response
Abbreviations: LMA – laryngeal mask airway; ETI – Endotracheal Intubation; GEB – Gum Elastic Bougie; ETT –Endotracheal tube; PLMA – Laryngeal Mask Airway ProSeal
Citation: Upadhyay MK, Kumar G, Chaurasia A, Narang D. Evaluation of gum elastic bougie guided Proseal laryngeal mask airway insertion technique. Anaesth. pain intensive care 2021;25(3):338–344. DOI: 10.35975/apic.v25i3.1531
Received: March 20, 2021; Reviewed: April 11, 2021; Accepted: May 11, 2021
Introduction
The laryngeal mask airway (LMA) is a supraglottic airway route tool, presented by Dr. Archie Brain in 1983. It fills the hole in airway route between tracheal intubation and utilization of the face mask. The main benefit of LMA over endotracheal tube (ETT) is that it avoids the use of laryngoscope to visualize and penetrate the laryngeal opening and hence produces less hemodynamic changes.1, 2
In the year 2000 a new version of LMA was introduced by the manufacturer named LMA ProSeal™ (PLMA), which incorporates another tube to allow second seal against upper esophageal sphincter giving continuity with the alimentary tract and isolating it from the airway.3 PLMA can achieve an additional effectual seal and facilitates gastrointestinal tube positioning without an expansion in straightforwardly estimated mucosal pressure.4,5
PLMA route is intended to be embedded utilizing either forefinger or introducer tool (IT) as described by the manufacturer.6 However, another new method of insertion has recently been described which involves the use of gum elastic bougie (GEB). The drain tube of PLMA is primed with bougie whose distal end is placed in the esophagus under laryngoscopic guidance. Then the PLMA is inserted digitally along palatopharyngeal curve and bougie removed.7 The authors claimed that GEB guided inclusion of PLMA has a higher first endeavor achievement rate as analyzed to other methods (GEB, 100%; digital 88%; IT 84%)8 and is linked with slight hemodynamic changes and a less prevalence of injury.7 The main cause of insertion difficulty with older techniques is disorder of PLMA sleeve on rear of the mouth and incompetent of the distal sleeve to arrive at the hypopharynx which is overcome by GEB guided technique.9
Laryngoscopy has been implicated as the main culprit for increase in pressor response due to stimulation of base of the tongue induced by the tip of its blade lifting the epiglottis.7 The most significant factor affecting the cardiovascular reaction is interval for laryngoscopy and powers applied during it.8,9
Hence this seems likely that laryngoscopic assisted PLMA placement with GEB guided technique might also have increased pressor response thus nullifying its advantage of being a supraglottic device. Keeping this in mind, it was proposed to study the difference in pressor responses with this technique of insertion of PLMA as against conventional placement of ETT which also requires laryngoscopy.
Methodology
100 normotensive patients of either sex having a place with ASA I or II, between 20-40 y old, booked to go through elective medical procedure, requiring general sedation were incorporated.
Patient with a known or anticipated complicated airway, mouth starting < 2.5 cm, Body mass index > 35 kg/m, any patient with a history of regurgitation, known case of hypertension and ischemic heart disease.
In this forthcoming randomized preliminary, every one of the patients were inspected during the preoperative visit a day prior to surgery. Insights about the patient's clinical history, physical assessment, Mallampati score, mouth opening, and basic routine investigations were recorded. Notified consent was taken for patient's involvement in the examination. Each patient was continued fasting for six hours before booked season of a medical procedure and premedicated with tablet alprazolam 0.25 mg and tablet ranitidine 150 mg orally at bedtime and at two hours preoperatively. On arrival of the patient in the operating room, non-invasive blood pressure (NIBP), ECG and pulse oximetry were recorded using Siemens SC 5000 monitor. Basal readings of systolic (SBP) and Diastolic Blood Pressure (DBP), Heart Rate (HR) and arterial saturation of oxygen (SpO2) on air were noted. An intravenous line was started. Patients were then randomly assigned to either Group PLMA (n = 50) or Group ETT (n = 50).
Patient's head was placed on a 7 cm tall pad of and neck was flexed and head extended i.e. the standard sniffing position for intubation. After induction using sleep dose of thiopentone 4-6 mg/kg followed by 0.1 mg/kg vecuronium bromide patients were ventilated for 2 min via face mask using Bain’s breathing system.
For patients in PLMA Group, a well lubricated PLMA loaded with GEB with fully deflated cuff, size 3 for females or size 4 for males, was introduced using standard midline approach i.e., positioned the GEB 5-10 cm into the throat under direct laryngoscopic direction, advanced the PLMA against palatopharyngeal curve utilizing digital guidance when an associate held the curved end of bougie, withdrawing the bougie while holding the PLMA in position. Then the cuff was inflated with sufficient air to keep cuff pressure around 60 cmH2O. The correct placement of PLMA was judged clinically by the capacity to ventilate the patient without substantial leak at an air pressure of < 20 cmH2O and by auscultation of breath sounds.
.
.
For Group ETT patients, an appropriate size cuffed
ETT (size 7.0 mm / 7.5 mm ID for females and size 8.0 mm / 8.5 mm ID for males) was inserted using standard technique for intubation.
General anesthesia in both groups was administered with 0.5% halothane and 67% nitrous oxide in O2. Heart rate (HR), SBP, DNP, MAP and SpO2 were recorded at following time intervals;
Tb – Basal i.e. before start of induction of anesthesia
T0 – Just before PLMA or ETT insertion but after administration of thiopentone and vecuronium bromide
T1 – One minute after successful placement of PLMA/ETT
T3 – Three minutes after successful placement of PLMA/ETT
T5 – Five minutes after successful placement of PLMA/ETT
T7 – Seven minutes after successful placement of PLMA/ETT
Number of attempts, duration of laryngoscopy and time required for the proper placement of PLMA/ETT were recorded. Time required for successful placement was measured from the start of laryngoscopy to the confirmation of proper placement.
At the end of a surgical procedure, neuromuscular block was reversed with atropine 0.02 mg/kg and neostigmine 0.05 mg/kg. Any postoperative complexities like cough, sore throat, hoarseness of voice was noted.
Statistical Analysis: Parameters collected were compiled and analyzed utilizing matched and unmatched ‘t’ test, chi-square test and Fisher precise analysis. Data is presented as Mean ± SD or n (%).
Results
Demographic data of the patients are compared in Table 1. The differences were statistically not significant.
The comparative duration of laryngoscopy and time taken to successful placement of airway device in two groups is presented in Table 2. The difference was statistically highly significant (p < 0.001).
In Table 3 mean heart rates in both of the groups at all specified time interval is comparable except at one minute after airway insertion when the rise in the heart rate in Group B was significantly more than Group A.
The baseline (TB) systolic blood pressure (SBP) as well as blood pressure just before airway placement but after induction i.e (T0) were statistically equivalent in two groups (p > 0.05). However, at one minute and at 3 min after ETT/PLMA placement (T1) the rise in SBP was greater in Group B as compared to Group A (p < 0.001). The variation in rise in SBP in both the groups remained statistically significant till T3, after which it returned to near base line values (T5) or even low (T7) (Table 3).
| Table 3: Comparative duration of laryngoscopy and time to successful placement | ||||
| Parameter | Time | PLMA Group | ETT Group | p value |
| Heart rate | TB | 81.96 ± 12.21 | 85.26 ± 16.05 | > 0.05 |
| T0 | 87.92 ± 13.93 | 90.62 ± 10.58 | > 0.05 | |
| T1 | 96.30 ± 16.02 | 104.34 ± 13.10 | > 0.05* | |
| T3 | 92.08 ± 19.93 | 97.44 ± 11.39 | > 0.05 | |
| T5 | 84.46 ± 13.88 | 90.80 ± 11.60 | > 0.05 | |
| T7 | 80.14 ± 13.19 | 84.22 ± 9.36 | > 0.05 | |
| Systolic blood pressure | TB | 122.96 ± 12.97 | 124.22 ± 11.72 | > 0.05 |
| T0 | 108.64 ± 10.41 | 104.54 ± 11.56 | > 0.05 | |
| T1 | 135.52 ± 16.30 | 146.96 ± 14.36 | < 0.001** | |
| T3 | 123.74 ± 13.09 | 131.54 ± 13.99 | < 0.001** | |
| T5 | 122.26 ± 45.20 | 120.42 ± 12.51 | > 0.05 | |
| T7 | 113.80 ± 10.12 | 116.16 ± 12.41 | > 0.05 | |
| Diastolic blood pressure | TB | 78.32 ± 8.13 | 79.62 ± 7.81 | > 0.05 |
| T0 | 70.34 ± 3.45 | 67.98 ± 7.91 | > 0.05 | |
| T1 | 89.96 ± 14.13 | 97.56 ± 12.96 | < 0.001** | |
| T3 | 80.40 ± 10.25 | 87.12 ± 7.62 | < 0.001** | |
| T5 | 75.56 ± 8.86 | 79.20 ± 8.39 | > 0.05* | |
| T7 | 74.58 ± 8.13 | 76.48 ± 9.16 | > 0.05 | |
| Mean arterial pressure | TB | 93.20 ± 9.04 | 94.48 ± 8.48 | > 0.05 |
| T0 | 83.10 ± 7.65 | 80.16 ± 8.4 | > 0.05 | |
| T1 | 105.14 ± 14.45 | 114.03 ± 12.59 | > 0.05* | |
| T3 | 94.84 ± 10.62 | 101.92 ± 8.86 | > 0.05* | |
| T5 | 91.13 ± 18.38 | 92.94 ± 9.05 | > 0.05 | |
| T7 | 87.65 ± 8.17 | 89.70 ± 9.42 | > 0.05 | |
| Data given as Mean ± SD; *p (Significant); **p < 0.001 (highly significant) | ||||
| Table 4: Incidence of adverse effect in two groups at removal of airway | |||
| Adverse effect | PLMA Group | ETT Group | p value |
| Sore throat | 1 (2) | 2 (4) | > 0.05 |
| Cough | 5 (10) | 13 (26) | < 0.05* |
| Hoarseness | 0 | 1 (2) | > 0.05 |
| Data given as Mean ± SD; *p (Significant) | |||
The diastolic blood pressures (DBP) were statistically comparable in two groups (p > 0.05) at TB, T0 and at T7 (p > 0.05). However, following airway placement at T1 there was a greater rise in DBP in Group B as compared to Group A (p < 0.001). The difference in both groups remained statistically significant till T5 which ultimately touched base line at T7 (i.e. 7 min after airway placement) (p > 0.05) (Table 3).
MAP at baseline (TB) as well as just before airway placement (T0) were statistically comparable in two groups (p > 0.05). At T1 and T3 MAP registered a significant rise which was more marked in Group B.
At 5 and 7 min after airway placement (T5 and T7) MAP returned to near baseline reading in both groups, which was statistically not significant (p > 0.05) (Table 3).
As shown in Table 4, the frequency of cough was higher in Group B as compared to Group A, which was statistically significtant (p < 0.05). On the other hand, occurrence of sore throat and hoarseness did not achieve statistical significance (p > 0.05) at airway removal in both groups.
Discussion
In our study in Group A patients, PLMA was used as an airway device which was introduced using GEB technique following laryngoscopy.7 In Group B patients, ETT was introduced using conventional technique. Pressor reactions as a rise in HR, SBP, DBP and MAP were recorded and compared using chi-square, paired and unpaired ‘t’ tests.
Pressor response is a common occurrence following laryngoscopy and tracheal intubation due to sympathoadrenal response in the form of a rise in catecholamine concentration.7 Shribman et al. suggested that the main reason of sympathoadrenal response to tracheal intubation is the stimulation of upper airways by laryngoscope. He added that the introduction of tracheal tube through the vocal cords and inflating a cuff in the infraglottic area donate small added inspiration.10
To avoid pressor response to laryngoscopy, supraglottic devices have been introduced in anaesthesia practice which do not require laryngoscopy for their placement. One such device is PLMA, which has been used in this study.
Conventionally PLMA is placed using either index finger or introducer tool technique. However, Hawath et al. reported that the GEB aided placement of PLMA under laryngoscopic guidance is better than index finger or introducer tool technique. They suggested that GEB guides the tip of PLMA towards the hypopharynx and prevents its impaction at the back of the pharynx.11 He evaluated this new technique and concluded that it is associated with no difference in heart rate or blood pressure.7
In our study, however, laryngoscopic assisted GEB guided placement of PLMA was associated with considerable rise in MAP and HR. This difference might be because of differences in the method of induction in the two studies. While we used sleep dose of thiopentone and vecuronium bromide for induction of anesthesia in our patients, Howath et al. used midazolam, fentanyl and propofol. Midazolam and fentanyl used in their study are known to modulate the pressor response of laryngoscopy. Also use of propofol for induction of anesthesia is known to achieve greater fall in blood pressure in comparison with the use of thiopentone alone. Moreover, they also used lack of response to jaw thrust as an end point of induction, unlike our study where we used loss of eye lash reflex for the same. It is a known fact that lack of response to jaw thrust requires deeper planes of anesthesia as compared to loss of eyelash reflex which might explain milder pressor response in their study. This interpretation is in compliance with the analysis conducted by Yakaittis et al. which concluded that greater depth of anesthesia abolishes the tracheal and carinal reflexes which are responsible for the pressor response.12
In our study, the time duration of laryngoscopy and time of placement of PLMA/ETT were remarkably elevated in PLMA as compared to ETT Group (12.69 and 35.71 sec. vs 10.76 and 21.30 sec.) respectively. It is well known that hemodynamic response to laryngoscopy is proportional to the duration of laryngoscopy.13
In our study, basal hemodynamic values were equivalent in both the category. Following laryngoscopy and PLMA/ETT placement BP and HR elevated pointedly in both the groups. The rise in BP and HR following PMLA placement was significantly less marked than tracheal intubation (p < 0.05). Hence, it is evident from the above observations that, although duration of laryngoscopy was more in PLMA Group, pressor response was more in ETT Group. This interpretation is in compliance with the study conducted by Hassan et al. which states that laryngoscopy stimulates the proprioceptors at the base of tongue leading to stimulus reliant increase of pressor response and catecholamine concentration and subsequent orotracheal intubation recruits additional receptors that augment the hemodynamic and catecholamine responses to laryngoscopy.13
Our study is also in agreement to an evaluation carried out by Ganzouri et al. who compared the pressor responses of PLMA using index finger/introducer tool technique with those of endotracheal intubation. They concluded that endotracheal intubation is associated with significant pressor response, while it is minimal with the use of PLMA with standard technique.14 Similarly, Evan et al., while evaluating PLMA using index finger/introducer tool technique, observed minimal hemodynamic response to its insertion in their patients. On the other hand, laryngoscopic assisted PLMA guided placement of PLMA in our study was associated with significant pressor response.15 Two reasons can be elicited for this discrepancy of observation. One obvious reason is that we used laryngoscopic assisted GEB guided technique for PLMA placement, while Evan et al. used conventional index finger or introducer tool technique. Another reason is difference in method of induction in two studies. While we used sleep dose of thiopentone and vecuronium bromide for induction, Evan et al. also used fentanyl and propofol for induction of anesthesia in their study.
Braun et al. reported that using the standard technique, hemodynamic responses to PLMA insertion and classic LMA insertion were similar,16 Jung et al., while evaluating LMA in children, reported that when insertion of classic LMA using laryngoscopic guidance is associated with greater hemodynamic response as compared to, when inserted using index finger technique.17
It can be postulated from our study that laryngoscopy assisted GEB guided placement of PLMA is associated with pressor response, which is although lesser then laryngoscopy followed by intubation, but greater than PLMA when inserted using standard technique.
Conclusion
This study suggests that GEB primed laryngeal mask airway Proseal™ when placed under laryngoscopic guidance, is associated with pressor response in the form of an increase in pulse rate and blood pressure. However, this pressor reaction is of lesser magnitude and lasts for lesser duration as compared to laryngoscopy and intubation.
Conflict of interest
None declared by the authors.
Authors’ contribution
MKU: Conceived and designed the analysis, collected the data
GK: Collected the data, contributed data analysis tools
AC: Performed the analysis; manuscript writing
DN: Data analysis, literature search, reference search, manuscript editing
References
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- Ganong WF. The autonomic nervous system (Review of Medical Physiology) 1987;ed. 13th. p(183-8).
- McCoy EP, Mirakheir RK, McCloskey BV. A comparision of the stress response to laryngoscopy – The Macintosh versus the McCoy blad. Anaesthesia. 1995;50:943-6. [PubMed] [Free Full Text] DOI: 1111/j.1365-2044.1995.tb05924.x
- Brimacombe J, Keller C, Judd DV. Gum elastic bougie guided insertion of the ProsealTM laryngeal mask airway is superior to the digital and introducer tool techniques. Anaesthesiology. 2004;100:25-9. [PubMed] [Free Full Text] DOI: 1097/00000542-200401000-00008
- Howath A, Brimacombe J, Keller C. Gum elastic bougie-guided insertion of the proseal laryngeal mask airway: a new technique. Anaesth Intensive Care. 2002 Oct;30(5):624-7. [PubMed] [Free Full Text] DOI: 1177/0310057X0203000514
- Proseal LMA. Instruction Manual. Henley-on-Thames: The Laryngeal Mask Airway Company Ltd.; 2000.
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- Brimacombe J, Keller C. The proseal laryngeal mask airway, a randomised, cross over study with the standard laryngeal mask airway in paralyzed, anesthetized patients. Anesthesiology. 2000;93:104-9. [PubMed] [Free Full Text] DOI: 1097/00000542-200007000-00019
- Brain AIJ, Verghese C, Strube PJ. The LMA ‘Proseal’– a laryngeal mask with an oesophageal vent. Br J Anaesth. 2000;84:650-4. [PubMed] [Free Full Text] DOI: 1093/bja/84.5.650
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- Brain AI. The laryngeal work –a new concept in airway management. Br J Anaesth. 1983;55:801-4. [PubMed] [Free Full Text] DOI: 1093/bja/55.8.801
- Yakaitis RW, Blitt CD, Angiul JP. End tidal halothane concentration for endotracheal intubation. Anesthesiology. 1977;47:386-8. [PubMed] [Free Full Text] DOI: 10.1097/00000542-197901000-00017
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- Ganzouri AE, Avramov MN, Budac S, Moric M, Tuman KJ. Proseal laryngeal mask airway versus endotracheal tube: Ease of insertion, hemodynamic responses and emergence characteristics: Anaesthesiology 2003; 99: A571 (Abstract). [Free Full Text]
- Evans NR, Gardner SV, James MFM, King JA. Roux P, Bennett P, et al. The Proseal laryngeal mask: results of a descriptive trial with experience of 300 cases. Br J Anaesth. 2002;88(4):534-9. [PubMed] [Free Full Text] DOI: 10.1093/bja/88.4.534
- Braun U, Zerbst M, Fulle Krug B, Gentzel I, Hempel V, Leier M, et al. A comparison of the proseal laryngeal mask to the standard laryngeal mask on anaesthetized, non-relaxed patients. Anasthesiol Intensivmed Notfallmed Schmerzther. 2002;37(12):727-33. [PubMed] [Free Full Text] DOI: 10.1055/s-2002-35911
- Jung KW, Cho CK, Yang HS. Clinical investigation of laryngeal mask airway in children (Korean). Korean J Anesthesiol. 1993; 26(4): 763-9.
| LMA-PROSEAL™ USAGE OVERVIEW
Preparation • Fully deflate the LMA-ProSeal™ to a high vacuum immediately before it is sterilized • Do not allow water to enter the LMA-ProSeal™ • Carry out the performance tests before each use Insertion • Ensure correct deflation of the LMA-ProSeal™ before attempting insertion • Use one of the recommended insertion techniques; do not use non-recommended techniques • Do not use excessive force to insert the LMA-ProSeal™ • If using the LMA-ProSeal™ Introducer, always remove it from the LMA-ProSeal™ after insertion and before inflation • Use sufficient lubricant to prevent the mask folding backwards during insertion Inflation and positioning • Inflate to a "just seal" pressure. Do not inflate to more than 60cm H2 0 intracuff pressure • Check for correct placement of the LMA-ProSeal™ by gentle lung inflation • If gas leaks through the drain tube, the device must be repositioned more deeply • If there is obstruction to lung inflation, remove the device and reinsert • Ensure the bite-block is between the teeth Oro-gastric tube • Do not pass an oro-gastric tube when there is either airway obstruction or an inadequate seal • Do not pass an oro-gastric tube when there is known or suspected esopharyngeal damage • Do not cool or refrigerate an oro-gastric tube before use Reuse • Do not use the LMA-ProSeal™ more than 40 time Credits: Copyright© The Laryngeal Mask Company Limited, 2000 |