Effect of anaesthesia on respiratory function after major lower extremity surgery. A comparison between bupivacaine spinal analgesia with low-dose morphine and general anaesthesia

Effects of propofol, desflurane, and sevoflurane on respiratory functions following endoscopic endonasal transsphenoidal pituitary surgery: a prospective randomized study

Background

General anesthesia with intravenous or inhalation anesthetics reduces respiratory functions. We investigated the effects of propofol, desflurane, and sevoflurane on postoperative respiratory function tests.

Methods

This single-center randomized controlled study was performed in a university hospital from October 2015 to February 2017. Ninety patients scheduled for endoscopic endonasal transsphenoidal pituitary surgery were randomly categorized into either of these three groups: propofol (n = 30, the Group TIVA), desflurane (n = 30, the Group D) or sevoflurane (n = 30, the Group S). We analyzed the patients before, after, and 24 h following surgery, to identify the following parameters: forced expiratory volume in 1 second (FEV₁) %, forced vital capacity (FVC) %, FEV₁/FVC, and arterial blood gases (ABG). Furthermore, we also recorded the intraoperative dynamic lung compliance and airway resistance values.

Results

We did not find any significant differences in FEV₁ values (primary outcome) among the groups (P = 0.336). There was a remarkable reduction in the FEV₁ and FVC values in all groups postoperatively relative to the baseline (P < 0.001). The FVC, FEV₁/FVC, ABG analysis, compliance, and airway resistance were similar among the groups. Intraoperative dynamic compliance values were lower at the 1st and 2nd hours than those immediately after intubation (P < 0.001).

Conclusions

We demonstrated that propofol, desflurane, and sevoflurane reduced FEV₁ and FVC values postoperatively, without any significant differences among the drugs.

Single-blinded, randomised preliminary study evaluating the effects of 2 Hz electroacupuncture for postoperative pain in patients with total knee arthroplasty

OBJECTIVE

To explore the point-specific clinical effect of 2 Hz electroacupuncture (EA) in treating postoperative pain in patients undergoing total knee arthroplasty (TKA), METHODS: In a randomised, partially single-blinded preliminary study, 47patients with TKA were randomly divided into three groups: control group (CG, n=17) using only patient-controlled analgesia (PCA); EA group (EAG, n=16) with 2 Hz EA applied at ST36 (Zusanli) and GB34 (Yanglingquan) contralateral to the operated leg for 30 min on the first two postoperative days, also receiving PCA; and non-point group (NPG, n=14), with EA identical to the EAG except given 1 cm lateral to both ST36 and GB34. The Mann-Whitney test was used to show the difference between two groups and the Kruskal-Wallis test to show the difference between the three groups.

RESULTS

The time until patients first required PCA in the CG was 34.1±22.0 min, which was significantly shorter than the 92.0±82.7 min in the EAG (p<0.001) and 90.7±94.8 min in the NPG (p<0.001); there was no difference between the EAG and NPG groups (p>0.05). The total dosage of PCA solution given was 4.6±0.9 mL/kg body weight in the CG, 4.2±1.0 mL/kg in the EAG and 4.5±1.0 mL/kg in the NPG; there were no significant differences (p>0.05) among the three groups.

CONCLUSIONS

In this small preliminary study, EA retarded the first demand for PCA in comparison with no EA. No effect was seen on the total dosage of PCA required and no point-specific effect was seen.

Lung function after total intravenous anaesthesia or balanced anaesthesia with sevoflurane

BACKGROUND

We investigated the effects of total i.v. anaesthesia (TIVA) and balanced anaesthesia (BAL) with sevoflurane on postoperative lung function in patients undergoing surgery in the prone position.

METHODS

Sixty patients, aged 21-60 yr, undergoing elective lumbar disc surgery in the prone position were randomly allocated to undergo TIVA (propofol-remifentanil) or BAL (fentanyl-nitrous oxide-sevoflurane). Forced vital capacity (FVC), forced expiratory volume in 1 s, mid-expiratory flow (MEF 25-75), and peak expiratory flow were measured before and after general anaesthesia.

RESULTS

Both groups were similar with respect to patient characteristic data and preoperative lung function parameters. Irrespective of the type of anaesthesia administered, lung function parameters decreased after operation, with the decrease in FVC being greater after TIVA than after BAL with sevoflurane.

CONCLUSIONS

In patients emerging from general anaesthesia, postoperative reduction in FVC is greater after TIVA than after BAL with sevoflurane.

Comparison of perioperative spirometric data following spinal or general anaesthesia in normal-weight and overweight gynaecological patients

BACKGROUND

There is limited data comparing the impact of spinal anaesthesia (SA) and general anaesthesia (GA) on perioperative lung function. Here we assessed the differences of these two anaesthetic techniques on perioperative lung volumes in normal-weight (BMI < 25) and overweight (BMI 25-30) patients using spirometry.

METHODS

We prospectively studied 84 consenting patients having operations in the vaginal region receiving either GA (n = 41) or SA (n = 43). Both groups (GA and SA) were further divided into two subgroups each (normal-weight vs. overweight). We measured vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), midexpiratory (MEF25-75) and peak expiratory flow rates (PEFR) at the preoperative assessment (baseline), after premedication, after effective SA, and 20 min, 1 h, 2 h and 3 h after the operation (last measurement after patient mobilization).

RESULTS

Premedication was associated with a small but significant decrease in lung volumes in direct correlation with BMI (-5%). Spinal anaesthesia resulted in a significant reduction in lung volumes in overweight as opposed to normal-weight patients. Postoperatively, lung volumes were significantly more reduced following GA than SA as indicated by differences in mean VC (SD) of -12 (6)% vs. -6 (5)% 20 min after the end of the operation in the normal-weight and -18 (5)% vs. -10 (5)% in the overweight patients. There was a significant impact of BMI on postoperative respiratory function, which was significantly more important in the GA group than in the SA group, and recovery of lung volumes was more rapid in the normal-weight patients than in the overweight patients, particularly in the SA group.

CONCLUSION

In gynaecological patients undergoing vaginal surgery, the impact of anaesthesia on postoperative lung function as assessed by spirometry was significantly less after SA than GA, particularly in overweight patients.

Transcutaneous electrical nerve stimulation for postoperative pain relief after total knee arthroplasty

Transcutaneous electrical nerve stimulation (TENS) has been used to treat chronic pain syndromes and has been reported to be of some utility in the treatment of postsurgical pain. A randomized, blinded, placebo-controlled trial was designed to evaluate the utility of TENS after total knee arthroplasty. Patients were randomly enrolled into patient-controlled anesthesia (PCA) alone, PCA plus TENS, or PCA plus sham TENS. The cumulative dose of morphine by PCA for each group was used as the end-point of the study. There was no significant reduction in the requirement for patient-controlled analgesia with or without TENS. We conclude that there is no utility for TENS in the postoperative management of pain after knee arthroplasty.

Impact of laryngeal mask airway and tracheal tube on pulmonary function during the early postoperative period

BACKGROUND

The tracheal tube (TT) produces reversible bronchoconstriction and increases pulmonary airway resistance compared to the laryngeal mask airway (LMA). The possible persistence of this effect in the postoperative period has not been studied. The aim of this study was to compare the early postoperative pulmonary function in healthy patients undergoing minor surgical procedures with the LMA or with the TT.

METHODS

Sixty patients scheduled for saphenous vein stripping under general anaesthesia were randomised to receive the LMA or the TT. Before anaesthesia and 20 min after LMA or TT removal, pulse oxymetry values (SpO(2)) were recorded and patients performed forced spirometry in the supine position.

RESULTS

Preoperative pulmonary function was normal in both groups. There were no differences between groups in the preoperative respiratory function test and SpO(2). Following surgery SpO(2), forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow (PEF) decreased in both groups. The FEV1/FVC did not change in either of the groups. In the TT group, compared to patients using the LMA, there was a greater relative decrease of SpO(2) (2.7 +/- 2.7% vs. 1.3 +/- 2.2%, P=0.017), FEV1 (17.6 +/- 12.2% vs. 8 +/- 17.4%, P=0.008), FVC (15.8 +/- 12.4% vs. 9 +/- 13.4%, P=0.023) and PEF (20.6% +/- 15.3% vs. 8.1 +/- 33.3%, P=0.033).

CONCLUSIONS

This study demonstrates greater early postoperative respiratory restrictive syndrome and lower arterial oxygen saturation following tracheal intubation compared to LMA use in patients without respiratory disease.

Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials

OBJECTIVES

To obtain reliable estimates of the effects of neuraxial blockade with epidural or spinal anaesthesia on postoperative morbidity and mortality.

DESIGN

Systematic review of all trials with randomisation to intraoperative neuraxial blockade or not.

STUDIES

141 trials including 9559 patients for which data were available before 1 January 1997. Trials were eligible irrespective of their primary aims, concomitant use of general anaesthesia, publication status, or language. Trials were identified by extensive search methods, and substantial amounts of data were obtained or confirmed by correspondence with trialists.

MAIN OUTCOME MEASURES

All cause mortality, deep vein thrombosis, pulmonary embolism, myocardial infarction, transfusion requirements, pneumonia, other infections, respiratory depression, and renal failure.

RESULTS

Overall mortality was reduced by about a third in patients allocated to neuraxial blockade (103 deaths/4871 patients versus 144/4688 patients, odds ratio=0.70, 95% confidence interval 0.54 to 0.90, P=0. 006). Neuraxial blockade reduced the odds of deep vein thrombosis by 44%, pulmonary embolism by 55%, transfusion requirements by 50%, pneumonia by 39%, and respiratory depression by 59% (all P<0.001). There were also reductions in myocardial infarction and renal failure. Although there was limited power to assess subgroup effects, the proportional reductions in mortality did not clearly differ by surgical group, type of blockade (epidural or spinal), or in those trials in which neuraxial blockade was combined with general anaesthesia compared with trials in which neuraxial blockade was used alone.

CONCLUSIONS

Neuraxial blockade reduces postoperative mortality and other serious complications. The size of some of these benefits remains uncertain, and further research is required to determine whether these effects are due solely to benefits of neuraxial blockade or partly to avoidance of general anaesthesia. Nevertheless, these findings support more widespread use of neuraxial blockade.

Influence of intrathecal morphine and naloxone intervention on postoperative ventilatory regulation in elderly patients

Thirty elderly patients undergoing major hip surgery under spinal analgesia were randomly allocated in a double-blind manner into three groups. The aim was to evaluate the influence of intrathecal morphine and postoperative naloxone infusion on the regulation of ventilation. The Bupivacaine Group received spinal analgesia with 20 mg bupivacaine intrathecally. The Morphine Group received spinal analgesia with 20 mg bupivacaine + 0.3 mg morphine intrathecally. The Naloxone Group received spinal analgesia with 20 mg bupivacaine + 0.3 mg morphine intrathecally + postoperative naloxone infusion intravenously (1 microgram/kg/h over 12 h, 0.25 micrograms/kg/h over the next 12 h). Evaluation of resting ventilation and the ventilatory responses to hypercarbia and hypoxaemia was made on three occasions: before surgery, and 8, and 24 h after the intrathecal injection. Intrathecal morphine had no significant effect on ventilatory regulation in elderly patients undergoing major hip surgery performed under bupivacaine spinal analgesia. Postoperative administration of opioids or sedatives after intrathecal morphine as well as postoperative blood loss associated with a fall in blood pressure appeared to increase the risk of developing respiratory depression. Naloxone infusion seemed to reduce the risk of developing respiratory depression. Furthermore, one third of the elderly had a poor response to hypoxaemia before surgery.

Does the anesthetic method influence the postoperative breathing pattern and gas exchange in hip surgery? A comparison between general and spinal anesthesia

We studied the effects of elective hip surgery, performed under either spinal (SA, n = 10) or general anesthesia (GA, n = 10), on breathing pattern and gas exchange. Measurements were made with respiratory inductive plethysmograph and indirect calorimetry in two positions before and after surgery. The method of anesthesia had no effect on the severity of postoperative hypoxemia. Reduced arterial oxygenation (PaO2; P less than 0.001, SA from 12.5 +/- 2.37 kPa to 10.5 +/- 1.38 kPa, GA from 12.5 +/- 2.95 kPa to 10.5 +/- 1.75 kPa) despite increased alveolar ventilation (P less than 0.01; from 2.30 +/- 0.37 l/min to 2.39 +/- 0.43 l/min in SA, 2.27 +/- 0.56 l/min to 2.57 +/- 0.35 l/min in GA) and reduced arterial carbon dioxide partial pressure (PaCO2; SA from 5.20 +/- 0.22 kPa to 4.95 +/- 0.33 kPa, P less than 0.01, GA from 5.07 +/- 0.36 kPa to 4.72 +/- 0.41 kPa, P less than 0.05) indicated maldistribution of ventilation and perfusion. Changes in breathing pattern and gas exchange and differences between the groups were minimal. Minute ventilation, tidal volume and mean inspiratory flow remained unchanged in both groups. The contribution of rib cage to tidal volume increased postoperatively in the supine position (P less than 0.001; SA from 32.6% +/- 10.3 to 46.3% +/- 7.5, GA from 36.5 +/- 16.4 to 48.5% +/- 15.4). CO2 production, oxygen consumption and energy expenditure remained unchanged. The postoperative changes in breathing pattern are related to the operation, not to the type of anesthesia and do not explain the alterations in gas exchange.

Epidural versus general anesthesia for infrainguinal arterial reconstruction

A prospective evaluation of 213 consecutive infrainguinal bypass procedures was performed to determine the effect of anesthesia technique on the postoperative complication rate. Limb salvage was the indication for surgery in 92% of cases. No significant differences were observed in age, sex, indication for surgery, presence of cardiovascular and pulmonary risk factors, American Society of Anesthesiologists classification, or Goldman scores between patients receiving epidural anesthesia and those receiving general endotracheal anesthesia. Epidural anesthesia was used for 96 procedures and general endotracheal anesthesia was used in 117 cases. Cardiac complications for the epidural anesthesia and general endotracheal anesthesia groups, respectively, included a mortality rate of 5% versus 3%, nonfatal infarctions in 6% versus 7%, and reversible cardiac events in 14% versus 16%. A high-risk subgroup of 69 patients (American Surgical Association classes IV and V or Goldman score greater than 10 points) also had no significant difference in outcome between epidural anesthesia and general endotracheal anesthesia. Major noncardiac complications occurred in an additional 8% of each group. Regional and general anesthesia therefore produce equivalent cardiovascular risk for infrainguinal arterial reconstruction. These results suggest that indicated operations should not be postponed or avoided for patients either requiring or requesting general anesthesia. Furthermore, other investigations of cardiac risk in vascular surgery do not require a uniform anesthetic technique for valid interpretation of results.

A prospective study of risk factors and cardiopulmonary complications associated with anaesthesia and surgery: risk indicators of cardiopulmonary morbidity

The aims of this study were: 1) to describe the frequency and type of cardiopulmonary complications, 2) to identify factors significantly associated with cardiovascular and pulmonary complications associated with anaesthesia and surgery, and 3) to estimate the total risk of cardiopulmonary complications for an anaesthetic when a combination of risk factors is present. Seven thousand three hundred and six anaesthetized patients undergoing gastrointestinal, urological, gynaecological, and orthopaedic surgery were included in the study; 6.3% (1:16) had one or more cardiovascular complications requiring intervention associated with anaesthesia and surgery, and 4.8% (1:21) had pulmonary complications. The total incidence of patients with one or more complications associated with anaesthesia and surgery was 9.4% (1:11). Based on logistic regression analyses, our data indicate that the following patient categories constitute high risk patients with regard to cardiovascular complications: patients aged greater than or equal to 70 years, patients with a history of ischaemic heart disease (IHD) with previous myocardial infarction less than 1 year, a history of chronic heart failure (CHF), and in patients admitted to major surgery. The extent of pulmonary complications following anaesthesia and surgery was significantly correlated to patients aged greater than or equal to 70 years, preoperative chronic obstructive lung disease (COLD), major surgery, and to general anaesthesia involving muscle relaxants. Attempts to estimate the cardiopulmonary complications which may accompany anaesthesia and surgery provided important information about the anaesthetic course and outcome. With our model it seems possible to distinguish between very different levels of cardiopulmonary risk in the anaesthetic patient.

Continuous epidural anesthesia and postoperative epidural narcotics in vascular surgery

A combination epidural technique using local anesthetics intraoperatively and morphine postoperatively is shown to offer many advantages. These benefits include inhibition of the surgical stress response, decreased cardiorespiratory depression, decreased blood loss, decreased intubation and pulmonary infection, decreased thromboembolism, decreased hyperglycemic and hypertensive response, nitrogen sparing, a stable resting metabolic rate, prevention of immunosuppression, simplification of cerebral status monitoring, and earlier ambulation and hospital discharge. The main disadvantage in patients undergoing vascular procedures is the risk of epidural hematoma. A review of the literature confirms the extreme rarity of this risk and, in view of the emerging benefits, argues for reconsideration of epidural technique in vascular patients. The addition of epidural morphine to this combined technique affords a postoperative pain-free continuum unmatched by any other method. This significantly decreased pain stress in cardiac patients increases safety and comfort. In conclusion, epidural anesthesia and postoperative epidural narcotics provide a safe and reliable method of management for patients undergoing vascular procedures.