Laryngeal tube, laryngeal mask airway and endotracheal tube in difficult intubation: a comparative study

Forty five patients, ASA physical status I and II were studied. They were scheduled for elective surgical procedures in supine or lithotomy positions, in which neuromuscular blockade was part of anesthetic technique and the use of laryngeal mask airway [LMA] was appropriate. They were classified as Mallampati class 3 or 4. Exclusion criteria included: cardiovascular, respiratory disorders, morbid obesity, esopilageal reflux, hiatus hernia, any contraindication of inhalatinn induction of anesthesia and diseases of the neck. The patients were randomly divided lhto tIlrbb groups, 15 patients each, according to the intubating device: Group I [n=15]: endotracheal tube [ETT] [Control group], Group II: [LMA] and Group III: laryngeal tube [LT]. Each patient received 0.2mg Atropine Sulfate, no other pre-medication was given. After pre-oxygenation, anesthesia was induced using Volatile Induction and Maintenance Anesthesia [VIMA], N2O:O, [1:1] in sevoflurane concentrations- increased from I MAC by I %, gradually, until there is loss of lash reflex, relaxation of jaw, absence of movement, and absent response to painful stimulus. ETT was inserted using the laryngoscope. The classic LMA was inserted according to the manufacturer's instruction manual. Size 3 was used in the females and size 4 for males. The LT was inserted according to manufacturer's instructions, size 3 was used for patients less than 155 cm, a size 4 for those between 155-180 cm, and size 5 for those taller than 180 cm. Systolic and diastolic arterial pressure [SAP, DAP], and heart rate [HR] were recorded; before induction, and before insertion of the ETT or airway device, and 1,5,10 and 15 min after airway cotablishment and before reversal of the residual muscle relaxant effect. Blood samples were collected before induction, 1,5,10 and 15 min after intubation or insertion of the airway device and just before extubation/removal of the device: to determine plasma epinephrine, norepinephrine and cortisol levels. There were no significant demographic differences between the three groups. The duration of insertion of the ETT was relatively the longest [29.2+/-11.7 sec], compared to the LT [17.7+/-4.6] which was the shortest. Airway pressure was 22.7+/-4.3 cm H20 in case of ETT, 17.6+/-8.1 in LMA and 29.3+/-5.1 in LT. Ventilation was excellent in case of ETT. In LMA, ventilation was excellent in 5 cases, it in 3, fair in 4 and poor in 3 patients. In case of LT [Group III], ventilation was excellent in 9 cases, good in 4, fair in I and poor in I patient. In EU, [GI], HR increased from 64.3+/-11.7 before induction to 97.1+/-9.4, and reached 101.5+/-8.7 just before extubation. In LMA it was 69.6+/-9.4 after introduction of device, compared to 62.9+/-9.1 in case of LT. just before removal of the device; HR in LMA was 81.6+/-17.4 and 83.2+/-11.2 in LT. In case of ETT there was an increase SBP. DBP tip to [143 +/- 19 and 93 +/- 15 mmHg] 1mm after intubation, [141+/-21 and 91+/-12 mmHg] before extubation respectively. This increase was higher than that detected with the insertion of LMA [127+/-12 and 74+/-11mmHg] and LT [115 +/-7 and 65 +/- 16 mmHg]. Just before removal of airway devices SBP and DBP reached [126+/-13 and 80+/-15 mmHg] with LMA and [119+/-15 and 73+/-14 mmHg]. The mean maximal epinephrine and norepinephrine plasma concentrations after insertion of the ETT [51.3+/- 23.3 and 248+/-83pg/mL] respectively. LMA [22.1+/- 11.2 and 163+/-63 pg/mL, respectively] and LT [23.1+/- 17.4 and 153+/- 67pg/mL, respectively]. Just before extubation they reached [81.4+/-22.5 and 363+/-82 pg/mL] in ETT group, [47.1+/-26.2 and 246+/-78 pg/mL] in LMA group and [43.6+/-24.6 and 233+/-66 pg/mL] in LT. Plasma cortisol reached up to 403+/-21 nmo/L 1 min after intubation in ETT, 342+/-19 nmo/L in LMA group, and 348+/-13 nmo/L in LT group. Just before extubation plasma cortisol was 613+/-41 nmo/L in ETT [Group I 363+/-23 nmo/L and 371+/-13 nmo/L in LMA and LT groups respectively

Evaluation of respiratory functions in morbid obesity during laparoscopic and open surgery: a comparative study

Thirty morbidly obese patients, with body mass index [BMI] >40 kg/m2, ASA physical status II and III, were randomly divided into two equal groups, 15 patients each: GI [n = 15] was scheduled for laparoscopic surgery and GII [n = 15] was scheduled for open upper abdominal surgery. Their preoperative pulmonary function tests showed the following averages: FVC 85.10% +/- 3.21%, FEV1s 83.12% +/- 6.08% and FEF 25-75 was 88.76% +/- 7.22% of the normal predicated values [S0]. The spirometric data were repeated after 24 hr [S24] and 72 hr [S72]. Blood gas measurements during spontaneous respiration at room air before surgical intervention including an arterial oxygen tension [PaO2] of 76.49 +/- 7.64 mmHg, arterial carbon dioxide tension [PaCO2] of 37.73 +/- 2.04 and pH of 7.40 +/- 0.02. All measurements were performed with the patient in supine position at five time points. The measurements were arterial blood gases [ABG], alveolar-arterial oxygen difference calculated as an index of pulmonary shunt and arterial to end-tidal CO2 tension difference [delta P] calculated as an index of physiological dead space. The lung/chest wall compliance as well as the maximal and minimal resistance of the total respiratory system were investigated. In GI [laparoscopy], PaCO2, ETCO2, P [A-a] O2, alveolar-arterial oxygen difference and arterial to end-tidal CO2 tension difference and resistance showed a significant rise after CO2 peritoneal insufflation. All measurements returned to normal values by the end of surgery. In GII [open surgery], those measurements did not show any considerable change. The postoperative pulmonary functions showed a marked reduction in both groups but to a lesser degree in GI. However, GI returned to normal by the 3rd postoperative day

Cardiovascular and hematological consequences of transurethral resection of the prostate [a clinical and experimental study]

A saline prostate extract was prepared from the prostatic tissue obtained during benign transurethral resection of the prostate [TURP] from several surgical specimens. Forty-eight adult male cats were studied. They were assigned into two main groups: Group A [n = 24] in which the cats were heparinized during the experimental procedure for measuring the blood pressure, ECG and serum Na; group B [n = 24] in which the cats were not heparinized and hemoglobin, hematocrit, platelet count, prothrombin time [Pt] and concentration [PC], activated partial thromboplastin [APTT], fibrinogen and fibrinogen degradation product [FDP] were measured at 0, 60, 90 and 120 minutes post infusion. Each of groups A and B were further subdivided into subgroups [six cats each] according to infusion: group 1C, saline 15 ml [control for group 1]; group 1, saline prostate extract 15 ml; group 2C, saline 0.5 L/kg [control for group 2]and group 2, glycine 0.5 L/kg. A 90-minute infusion interval was selected for the model to correspond with the maximal infusion period that occurred clinically. Twenty-five patients ASA class I or II were prospectively randomized to undergo TURP under spinal anesthesia. All patients had symptomatic benign prostatic hyperplasia. In conclusion, the experimental work proved that infusion of prostate tissue extract resulted in no statistical or clinical changes in MBP, HG, or ECG; so, it was suggested that glycine is responsible for the cardiovascular changes during TUR syndrome. On the other hand, infusion of prostatic tissue extract resulted in coagulation defects which may contribute to postoperative morbidity. However, the exact mechanism of coagulopathy still needs further investigations to be more specified. Meanwhile, because TURP is one of the most popular urology surgeries in elderly patients all over the world, a care must be taken especially when the size of the gland is over 30-35 g and the duration of surgery is more than 40 minutes

comparison between auditory evoked potential index and bispectral index as a monitor of depth of anesthesia

In a trial to evaluate bispectral index [BIS] and auditory evoked potential index [AEP index] as monitors of depth of sedation and anesthesia in comparison with hemodynamics, 45 patients ASA I and II were studied. They were randomly divided into three groups, 15 patients each. They were all scheduled for elective, non-cardiac, non-neurological surgery with a lower abdominal incision not more than 5 cm long. Group I received general anesthesia [GA] using sevoflurane in 100% oxygen. Group II received general anesthesia [GA] using sevoflurane in nitrous oxide [oxygen 50%] and group III received combined general anesthesia [GA] using sevoflurane in 100% oxygen and epidural anesthesia. In this preliminary study, it was found that the value of hemodynamic monitoring as a monitor of depth of anesthesia was unreliable. Bispectral index and auditory evoked potential index are satisfactory monitors regarding the depth of sedation. While, AEP index was the more reliable monitor regarding the response to surgical stimulation. It is important to notice that during the use of balanced anesthesia, one single monitor is not enough to guarantee a good satisfactory depth of anesthesia