A Comparison of the Effects of Lung Protective Ventilation and Conventional Ventilation on Thermoregulation During Anaesthesia

Objective

During prolonged surgery, hypothermia is an unwanted condition that frequently develops and increases complication rates. It has been shown that positive end-expiratory pressure (PEEP) during mechanical ventilation reduces hypothermia development by providing earlier peripheral vasoconstriction. In the present study, an investigation was made of the effect of two different ventilation models on perioperative hypothermia development.

Methods

A total of 40 patients undergoing elective lumbar disc surgery were randomised to either the conventional group (Group C, n=20, tidal volume=10 mL kg^-1, PEEP=0 cm H₂O) or the lung protective ventilation group (Group P, n=20, tidal volume=6 mL kg^-1, PEEP=5 cm H₂O). Demographic data on gender, age, weight, height, preoperative-postoperative temperatures and haemodynamic values were recorded. The point where the forearm to fingertip skin temperature difference reached 0°C was determined as the peripheral vasoconstriction development. At this point, the core temperature was recorded as the thermoregulatory vasoconstriction threshold.

Results

Demographic characteristics of the patients and haemodynamic variables were similar between the groups. Preoperative and postoperative temperature gradients were not significantly different between the two groups (p=0.827). There was also no significant difference between the two groups in respect of the vasoconstriction threshold of the patients (p=0.432).

Conclusion

The study results showed that lung protective ventilation has no advantage in preserving the perioperative core temperature compared to conventional ventilation.

Does Listening to Music during Tonsillectomy Affect Sevoflurane Consumption?

OBJECTIVE

The aim of this study was to investigate the effect of listening to music on the consumption of an anesthetic agent as well as postoperative recovery and pain in children undergoing elective tonsillectomy.

MATERIALS AND METHODS

Fifty patients were randomized into those to whom music was played during surgery (group M) and a control group to whom music was not played (group C). The depth of anesthesia was provided by entropy levels of 50 ± 5 in both groups. Demographic characteristics and hemodynamic parameters were recorded perioperatively. The duration of surgery, sevoflurane consumption, eye opening time, and extubation time were also recorded. p < 0.05 was considered statistically significant.

RESULTS

Surgical pleth index values measured intraoperatively were statistically lower in group M than in group C. In the postanesthesia care unit children in the music group felt less pain than those in the control group according to the Wong-Baker Faces Pain Rating Scale (p = 0.035). The heart rates of the patients in the music group were statistically lower at 30 min intraoperatively and at the end of the procedure compared to the values of the control group (p = 0.015). The consumption of sevoflurane was lower in group M than in group C but the difference was not statistically significant. The need for additional fentanyl was significantly lower in group M than in group C.

CONCLUSION

In this study, the children exposed to music intraoperatively needed less analgesia during surgery, and reported less pain postoperatively, but there was no difference in sevoflurane requirements.

The Effect of Pressure-Controlled Ventilation and Volume-Controlled Ventilation in Prone Position on Pulmonary Mechanics and Inflammatory Markers

The aim of this present study is to compare the effect of pressure-controlled ventilation and volume-controlled ventilation on pulmonary mechanics and inflammatory markers in prone position. The study included 41 patients undergoing to vertebrae surgery. The patients were randomized into two groups: Group 1 received volume-controlled ventilation, while group 2 received pressure-controlled ventilation. The demographic data, pulmonary mechanics, the inflammatory marker levels just after the induction of anesthetics, at the 6th and 12th hours, and gas analysis from arterial blood samples taken at the beginning and the 30th minute were recorded. The inflammatory marker levels increased in both groups, without any significant difference among groups. Peak inspiratory pressure level was higher in the volume-controlled ventilation group. This study revealed that there is no difference regarding inflammatory marker levels between volume- and pressure-controlled ventilation.

Effects of N-acetyl cysteine on renal functions evaluated by blood neutrophil gelatinase-associated lipocalin levels in geriatric patients undergoing coronary artery bypass grafting

Objective:

Recent conflicting studies on the renal effects of N-acetyl cysteine (NAC) after cardiac surgery have been published. The aim of this study was to evaluate the renal effects of NAC using neutrophil gelatinase-associated lipocalin (NGAL) blood levels in elderly patients undergoing coronary artery bypass grafting (CABG).

Methods:

This randomized, double-blinded, placebo-controlled study was conducted among geriatric patients (>65 years) scheduled to undergo CABG. A total of 60 consecutive patients were randomly assigned to 2 groups. The first group received I.V. NAC (n=30) and the second group received placebo (n=30) at induction of anesthesia and then for 20 h. NGAL values were determined and conventional renal function tests were performed. Statistical analysis was performed using SPSS 17.0 (IL, Chicago, USA). A p value of <0.05 was considered statistically significant

Results:

Plasma creatinine levels at 24 h postoperatively were significantly higher in the placebo group than in the NAC group (1.41±0.63 vs. 1.13±0.35; p<0.05). The mean serum NGAL levels at 3 h postoperatively were higher in the placebo group than in the NAC group (104.94±30.51 vs. 87.82±25.18; p<0.05). NGAL levels were similar between the groups at all other measurement time points. Plasma creatinine levels of ≥1.5 mg/dL or >25% of the baseline value at any time during the study period were observed in 27% of patients in the NAC group and 37% of patients in the placebo group; the difference was statistically significant (p<0.05).

Conclusion:

In the present study, we found that I.V. NAC infusion in elderly patients undergoing CABG reduced the incidence of acute kidney injury as determined by blood NGAL and creatinine levels.

Effects of Parasternal Block on Acute and Chronic Pain in Patients Undergoing Coronary Artery Surgery

Background. Sternotomy causes considerable postoperative pain and postoperative pain management encompasses different analgesic regimens. In this study, we aimed to investigate the effect of peroperative parasternal block with levobupivacaine on acute and chronic pain after coronary artery bypass graft surgery. Materials and Methods. A total of 81 patients undergoing coronary artery bypass graft surgery were included in this study. Patients were randomly allocated by opening an envelope to receive either parasternal block with pharmacologic analgesia (group P; before sternal wire placement: sternotomy and mediastinal tube sites were infiltrated with local anesthetics) or pharmacologic analgesia alone (group C) for postoperative pain relief. All patients received intravenous tramadol with patient-controlled analgesia at the end of the surgery. Demographic characteristics, vital signs, tramadol consumption, analgesic intake, and intensity of pain with a visual analogue scale were recorded for each patient. Six months after surgery, the patients’ type of chronic pain was evaluated using the Leeds Assessment Neuropathic Symptoms and Signs pain scale questionnaire. Results. Patients who received parasternal block experienced less pain and needed less opioid analgesic (125.75 ± 28.9 mg in group P vs 213.17 ± 61.25 mg in group C) for 24 hours postoperatively ( P < .001). There was no significant difference in nociceptive and neuropathic pain between the groups. Conclusion. Parasternal block had a benefical effect on the management of postoperative acute pain and decreased opioid consumption after surgery but had no significant effect in chronic post surgical pain.

Effect of transversus abdominis plane block on cost of laparoscopic cholecystectomy anesthesia

Background

Use of transversus abdominis plane (TAP) block for postoperative analgesia is continuously increasing. However, few studies have investigated intraoperative effects of TAP block. We aimed to study the effects of TAP block in terms of cost-effectiveness and consumption of inhalation agents.

Material/Methods

Forty patients undergoing laparoscopic cholecystectomy were enrolled in this study. Patients were randomly divided into 2 groups: Group 1 (n=20) patients received TAP block and Group 2 (n=20) patients did not receive TAP block. Standard anesthesia induction was used in all patients. For the maintenance of anesthesia, fractional inspired oxygen (FIO2) of 50% in air with desflurane was used with a fresh gas flow of 4 L/min. All patients were monitored with electrocardiography and for peripheral oxygen saturation (SpO2), end-tidal carbon dioxide (ET), heart rate (HR), noninvasive mean blood pressure (MBP), and bispectral index (BIS). Bilateral TAP blocks were performed under ultrasound guidance to Group 1 patients. The BIS value was maintained at between 40 and 50 during the surgery. The Dion formula was used to calculate consumption of desflurane for each patient.

Results

There was no difference between the groups with respect to demographic characteristics of the patients. Duration of anesthesia, surgery time, and dosage of fentanyl were similar in the 2 groups. However, the cost and consumption of desflurane was significantly lower in Group 1.

Conclusions

Total anesthesia consumption was lower and the cost-effectiveness of anesthesia was better in TAP block patients with general anesthesia than in non-TAP block patients undergoing laparoscopic cholecystectomy.

Exploring for the safer ventilation method in laparoscopic urologic patients? Conventional or low tidal?

BACKGROUND

To study the effects of low tidal volume with positive end-expiratory pressure (PEEP) on arterial blood gases of patients undergoing laparoscopic urologic surgeries.

SUBJECTS AND METHODS

Eighty-six laparoscopic urologic patients were enrolled in this study. Patients were randomized into two groups according to the ventilatory settings. In the conventional group (Group C) (n=43), the tidal volume was 10 mL/kg, and the PEEP was set at 0 cm of H2O. In the low tidal volume with PEEP group (Group LP), the tidal volume was 6 mL/kg, with PEEP of 5 cm of H2O. In both groups total minute volume was 6 L/kg. Peak and plateau airway pressure (PPEAK and PPLAT, respectively) and arterial blood gases were recorded before pneumoperitoneum (PNP) (T1) and the first and third hour (T3) after PNP induction and also after extubation in the intensive care unit. Additionally, heart rate, mean arterial pressure, and peripheral O2 saturation of hemoglobin were recorded.

RESULTS

Heart rate, PPEAK, and PPLAT values were similar in both groups. Partial arterial O2 pressure values measured postoperatively were significantly higher in Group LP, whereas those measured before PNP induction were similar (P=.014 and P=.056, respectively). Compared with the baseline, partial arterial CO2 pressure values measured at T1 and at T3 after PNP induction were significantly higher in Group C than in Group LP (P<.001). The pH values of Group C at T1 and at T3 postoperatively were significantly lower than the values of Group LP (P<.001). Extubation times were significantly lower in Group LP.

CONCLUSIONS

The results of the present study suggest that low tidal volume with PEEP application may be a good alternative for preventing high CO2 levels and yielding better oxygenation and lower extubation times in patients undergoing prolonged laparoscopic urology.