Checklist for anesthesiological process: analysis of risks

BACKGROUND

Several methods are reported in the literature to analyze medically undesirable events during hospital care. Each method has several limitations, so no one has been defined as the standard tool to be able to detect failure during a medical process. The aim of this study was to compare an anesthesiological perioperative checklist with traditional Regional Incident Reporting (RIR) form in detecting and describing failures.

METHODS

We analyzed RIR number of reports, seriousness and contributing factors. We also analyzed anesthesiological checklist data for: number of reports, seriousness of incident, contributing factors and distribution in macro-phases.

RESULTS

We screened 2681 patients who underwent gynecological and obstetrical surgeries. RIR showed only the most harmful events in 0.4% of surgeries. Conversely, we recorded 135 failures with anesthesiological checklists (3.3%), of which 123 (91.1%) were solved. Categories of incident in checklists were: failures for medical device/equipment (N.=30, 22.2%), for treatment/procedures (N.=25, 18.5%), for clinical assessment (N.=22, 16.2%), for consent/communication (N.=19, 14%), for medication (N.=16, 11.8%) and for documentation (N.=8, 5.9%). Ninety-four failures (69.6%) resulted in no harm for the patient, 41 (30.3%) in reversible damage and there were no cases of permanent damage/death. Contributing factors in checklists were mainly related to team (43.7%), task factors (28.1%) and work environment (22.2%). Failures detected in macro-phases were related to: clinical assessment (31.8%), presurgical re-assessment (23.7%), preparation for anesthesia (30.3%), anesthesia conduction (8.8%) and awakening (5.1%).

CONCLUSION

An anesthesiological checklist compared with traditional RIR provided a more sensible and complete framework for incident analysis during the perioperative period in patients undergoing gynecological and obstetrical surgeries.

ITalian Observational Study of the management of mild-to-moderate Post-Operative Pain (ITOSPOP)

BACKGROUND

The multicenter observational ITalian Observational Study on the management of mild-to-moderate PostOperative Pain (ITOSPOP) was carried out in 24 hospitals to describe current postoperative pain management in Italy and the intensity of pain experienced by patients during the first 48 hours after surgery.

METHODS

Adult patients, after surgery expected to result in mild-moderate postoperative pain, underwent six evaluations. The primary endpoint was the level of organization and standardization of postoperative pain management. Secondary objectives included the intensity of postoperative pain, and an assessment of incident pain, postoperative analgesic and concomitant treatment administration.

RESULTS

Only 16.7% hospitals had an acute pain service and 41.7% hospitals applied a standardized protocol for postoperative pain management. The majority (>60%) of the 1952 patients monitored underwent all six assessments, >70% of which were performed by a physician. The proportion of patients with moderate pain decreased during the study period, but almost 10% of patients still experienced moderate pain at study end. Mild pain was reported by 50% of the patients for the entire study duration. At the final assessment, 5% of patients still presented with incident pain frequently interfering with daily activities. Most patients were treated with analgesics, but 20% of patients did not receive any pain medications despite experiencing pain.

CONCLUSION

The level of organization and standardization of postoperative pain management in Italian hospitals remains low. Postoperative analgesic treatment remained suboptimal and almost two-thirds of patients continued to experience pain.

The Helsinki Declaration on Patient Safety in Anesthesiology: a way forward with the European Board and the European Society of Anesthesiology

Anesthesiology, which includes anaesthesia, perioperative care, intensive care medicine, emergency medicine and pain therapy, is acknowledged as the leading medical specialty in addressing issues of patient safety, but there is still a long way to go. Several factors pose hazards in Anesthesiology, like increasingly older and sicker patients, more complex surgical interventions, more pressure on throughput, as well as new drugs and devices. To better design educational and research strategies to improve patient safety, the European Board of Anesthesiology (EBA) and the European Society of Anesthesiology (ESA) have produced a blueprint for patient safety in Anesthesiology. This document, to be known as the Helsinki Declaration on Patient Safety in Anesthesiology, was endorsed together with the World Health Organization (WHO), the World Federation of Societies of Anesthesiologists (WFSA), and the European Patients' Federation (EPF) at the Euroanaesthesia meeting in Helsinki in June 2010. It was signed by several Presidents of National Anesthesiology Societies as well as other stakeholders. The Helsinki Declaration on Patient Safety in Anesthesiology represents a shared European view of what is necessary to improve patient safety, recommending practical steps that all anesthesiologists can include in their own clinical practice. The Italian Society of Anaesthesia, Analgesia, Reanimation and Intensive Care (SIAARTI) is looking forward to continuing work on "patient safety" issues in Europe, and to cooperating with the ESA in the best interest of European patients.

Usutu virus infection in a patient who underwent orthotropic liver transplantation, Italy, August-September 2009

We report a case of Usutu virus (USUV)-related illness in a patient that underwent an orthotropic liver transplant (OLT). Post transplant, the patient developed clinical signs of a possible neuroinvasive disease with a significant loss of cerebral functions. USUV was isolated in Vero E6 cells from a plasma sample obtained immediately before the surgery, and USUV RNA was demonstrated by RT-PCR and sequencing. This report enlarges the panel of emerging mosquito-borne flavivirus-related disease in humans.

Usutu virus infection in a patient who underwent orthotropic liver transplantation, Italy, August-September 2009

We report a case of Usutu virus (USUV)-related illness in a patient that underwent an orthotropic liver transplant (OLT). Post transplant, the patient developed clinical signs of a possible neuroinvasive disease with a significant loss of cerebral functions. USUV was isolated in Vero E6 cells from a plasma sample obtained immediately before the surgery, and USUV RNA was demonstrated by RT-PCR and sequencing. This report enlarges the panel of emerging mosquito-borne flavivirus-related disease in humans.

Use of recombinant factor IX and thromboelastography in a patient with hemophilia B undergoing liver transplantation: a case report

Hemophilia B is a congenital recessive disorder caused by deficiency of coagulation factor IX (FIX). Surgical procedures can be performed in patients with hemophilia using high-purity and/or recombinant FIX, which has been shown to be safe and effective in surgical hemostasis. Liver transplantation is the only potentially curative treatment available for these patients, providing a long-term phenotypic cure for hemophilia. End-stage liver disease together with hemophilia exposes patients to greater risks of bleeding complications during the perioperative period with consequent difficulties in managing coagulopathy. The limited experiences reported by different investigators and the various strategies for clotting factor replacement make it difficult to define a single approach with respect to the optimal dose and method of administering FIX to achieve perioperative hemostasis. The limits of plasma-based coagulation tests--prothrombin time, activated partial thromboplastin time--have made thromboelastography a valid alternative in this kind of surgery. It has been demonstrated to be a useful tool for real-time analysis of clot formation using a whole-blood assay format. Further, it accurately illustrates the clinical effects of procoagulant or anticoagulant interventions. In this article, we have described the usefulness of thromboelastography to monitor the ability of high-purity FIX supplementation to restore a normal coagulation state and to guide the perioperative administration of blood products in a successful orthotopic liver transplantation in a hemophilic patient with deficiencies of factors IX and X, presenting with hepatitis C virus-related cirrhosis and hepatocellular carcinoma.

Thymoglobulin-induced severe cardiovascular reaction and acute renal failure in a patient scheduled for orthotopic liver transplantation

Antithymocyte globulin (ATG) has been shown to be effective as a pretreatment immunosuppressive agent in liver transplantation because of the ability to wean tacrolimus monotherapy after 4 months in pretreated recipients. However, the use of ATG can be complicated by serious side effects. Reported side effects include severe cardiopulmonary reactions, adult respiratory distress syndrome and hematological disorders. We report a case of a patient with a medical history of cirrhosis scheduled for orthotopic liver transplantation that, during the operation, showed swelling, hyperthermia, tachycardia and hypotension after the administration of ATG. Acute renal failure (ARF) was another serious side effect that our patient developed during ICU stay; we ascribed the occurrence of ARF to the serum sickness disease triggered by the ATG administration. Only one case has been reported of ARF after ATG-therapy before our experience. Therefore, severe hyperthermia and signs of cardiovascular dysfunction early after the beginning of ATG administration should be carefully evaluated and may need to consider the immediate ATG therapy withdrawal to prevent ARF.

Wernicke's encephalopathy in a malnourished surgical patient: clinical features and magnetic resonance imaging

We report a clinical and neuroradiological description of a severe case of Wernicke's encephalopathy in a surgical patient. After colonic surgery for neoplasm, he was treated for a long time with high glucose concentration total parenteral nutrition. In the early post-operative period, the patient showed severe encephalopathy with ataxia, ophthalmoplegia and consciousness disorders. We used magnetic resonance imaging (MRI) to confirm the clinical suspicion of Wernicke's encephalopathy. The radiological feature showed hyperintense lesions which were symmetrically distributed along the bulbo-pontine tegmentum, the tectum of the mid-brain, the periacqueductal grey substance, the hypothalamus and the medial periventricular parts of the thalamus. This progressed to typical Wernicke-Korsakoff syndrome with ataxia and memory and cognitive defects. Thiamine deficiency is a re-emerging problem in non-alcoholic patients and it may develop in surgical patients with risk factors such as malnutrition, prolonged vomiting and long-term high glucose concentration parenteral nutrition.

Modifications of plasma concentrations of hormonal and tissue factors during mechanical ventilation with positive end-expiratory pressure

AIM

The aim of this study is to analyse if the decrease of cardiac performance due to positive end-expiratory pressure (PEEP) application, within low values applied in clinical practice (5 cm H(2)O) is able to trigger a response of the main endogenous factors which control and maintain the mean arterial pressure (MAP).

METHODS

This study was applied to 18 patients, admitted to the Intensive Care Unit (ICU) of the University Hospital of Modena, who underwent oro-tracheal intubation and mechanical ventilation. On admission, patients did not suffer from cardiac or lung disease. This study analyses plasma concentrations of epinephrine, norepinephrine, ET-1, NO metabolites, renin, aldosterone at 4 different times: before PEEP application, 60 minutes after the beginning of mechanical ventilation with PEEP, and respectively 30 and 60 minutes after withdrawal of PEEP. At the same time, MAP values and heart rate (HR) have been observed.

RESULTS

Results show an increase of epinephrine and norepinephrine after PEEP application and a decrease to basal values at PEEP withdrawal. All variations are statistically significant. After PEEP introduction, ET-1 showed an increased concentration, although it was not statistically significant, while a significant decreasing trend was observed after PEEP withdrawal. A significant increase of NO metabolite values has been observed together with the increase of ET-1, followed by a decrease to basal values after the withdrawal of PEEP. Concentrations of renin increased when PEEP was applied even though they were not significant and decreased significantly when PEEP was withdrawn. A similar trend was revealed by aldosterone even though it underwent constant significant variations.

CONCLUSION

The administration of PEEP produces an effective response of endogenous substances whose function is to maintain a proper tissue perfusion.

Intraoperative effects of combined versus general anesthesia during major liver surgery

AIM

The study compares the intraoperative effects of combined versus general anesthesia during major liver surgery.

METHODS

In this prospective randomized study, 70 patients were divided into 2 group of 35 subjects. Group A received general anesthesia (thiopentone, fentanyl, vecuronium, sevoflurane in a closed circuit) 15 minutes after placement of an epidural catheter (D9-D10) and induction of epidural anesthesia (6 ml 2% naropine). Continuous epidural infusion was initiated before surgical incision and continued with 0.2% naropine (7 ml/h) until the end of the operation. Group B received combined intraoperative anesthesia wit fentanyl doses according to hemodynamic parameters and 0.1 mg/kg morphine 30-4 minutes before cutaneous suture. Hemodynamic values were measured at base line (T0), and then at 15, 30, 60, 120 and 180 minutes after induction of general anesthesia (T1, T2, T3, T4 and T5, respectively). On recovery, patients were assessed for pain at rest and on movement reported on a visual analog scale; degree of motor blockade according to the Bromage scale; appearance of side effects; use af analgesic.

RESULTS

A statistically significant decrease in the mean arterial blood pressure (ABP) and heart rate (HR) was noted within each group at 15 minutes after induction of general anesthesia. Significant differences in ABP were found between the 2 groups at T1 to T5, whereas HR values were substantially similar. The mean intraoperative use of fentanyl was significantly higher in Group B than in Group A, as was that of vecuronium. Pain intensity on recovery in patients who received epidural anesthesia was lower both at rest and on movement; only the patients in Group B required additional analgesics. No motor blockade was observed in either group. Nausea and vomiting were more frequent in Group B; hypotension was more frequent in Group A.

CONCLUSION

The study confirms the safety of locoregional anesthesia in liver surgery, with good hemodynamic stability and absence of major side effects. The lower intraoperative use of opioids and muscle relaxants in patients who received epidural anesthesia confirms the neurovegetative protection this method provides. The data support the hypothesis that greater intraoperative use of opioids may be responsible for the higher incidence of side effects. Therefore, the intraoperative use of combined low-concentration anesthetic agents alone appears to offer a reasonable treatment option that provides adequate pain control at recovery from general anesthesia, with only minor side effects typically associated with analgesic (motor blockade) and opioids (nausea and vomiting). Given the complications associated with the technique, it should be performed by an expert anesthetist.

Early experiences with a porcine hepatocyte-based bioartificial liver in acute hepatic failure patients

Orthotopic liver transplantation (OLT) is the only effective therapeutic modality in severe acute hepatic failure (AHF). The scarcity of organs for transplantation leads to an urgent necessity for temporary liver support treatments in AHF patients. A hepatocyte-based bioartificial liver (BAL) is under investigation with the main purpose to serve as bridging treatment until a liver becomes available for OLT, or to promote spontaneous liver regeneration. We developed a novel radial-flow bioreactor (RFB) for three-dimensional, high-density hepatocyte culture and an integrated pumping apparatus in which, after plasmapheresis, the patient's plasma is recirculated through the hepatocyte-filled RFB. Two hundred thirty grams of freshly isolated porcine hepatocytes were loaded into the RFB for clinical liver support treatment. The BAL system was used 8 times in supporting 7 AHF patients in grade III-IV coma, all waiting for an urgent OLT Three patients with no history of previous liver diseases were affected by fulminant hepatic failure (FHF) due to hepatitis B virus, 3 by primary non-function (PNF) of the transplanted liver, and one by AHF due to previous abdominal trauma and liver surgery. Six out of 7 patients underwent OLT following BAL treatment(s), which lasted 6-24 hours. All patients tolerated the procedures well, as shown by an improvement in the level of encephalopathy, a decrease in serum ammonia, transaminases and an amelioration of the prothrombin time, with full neurological recovery after OLT Our initial clinical experience confirms the safety of this BAL configuration and suggests its clinical efficacy as a temporary liver support system in AHF patients.

[Life threatening asthma associated to severe pneumonia and acute myopathy]

A young male was transferred to our intensive care unit (ICU) from the intensive care unit of a local hospital where he was admitted for life-threatening asthma ten days before. As severe hypoxemia, we immediately started inhaled nitric oxide (iNO) that improved significantly pulmonary gas exchange. The first day after admission in our ICU, a chest computed tomography showed a three-lobar pneumonia and, therefore, a broad-spectrum antibiotic therapy was decided. iNO therapy was withdrawn 96 hours after the beginning because of a stable improvement of pulmonary gas exchange and a relative loss of efficacy. Five days after arrival in our ICU, sedative and neuromuscular blocking drugs initiated 15 days before were stopped and, after the awakening, the patient presented tetra-paresis. Muscle biopsy and electromyography indicated an acute myopathy that was probably caused by the association between large doses of steroids and neuromuscular blocking agents. In spite of an intensive physiotherapy program, the patient was extubated only 15 days after admission and he underwent non-invasive mechanical ventilation for further 7 days. The patient was discharged from our ICU 10 days after extubation with a good restore of muscle functioning which was complete two months later.

Delayed upper airway obstruction following a retropharyngeal haematoma after minor head trauma

The development of a retropharyngeal haematoma may occur rarely after major head, face or cervical spine injuries, and it is even less frequent following minor trauma. As these patients are commonly not intubated, a life-threatening upper airway obstruction may occur. We report the case of a man who experienced a late retropharyngeal haematoma with delayed, progressive upper airway obstruction after a minor frontal wound. After an emergency intubation a nuclear magnetic resonance highlighted the magnitude of the bleeding into the retropharynx accounting for the slow onset of the symptoms. Predisposing factors such as antithrombotic therapies and vascular lesions may enhance the risk of occurrence even after minor trauma. Hypotheses on how to identify this potentially fatal complication earlier are reported.

The hemodynamic and metabolic effects of tourniquet application during knee surgery

We evaluated the effects of tourniquet application on the cardiovascular system and metabolism in 10 young men undergoing knee surgery with general anesthesia. The duration of inflation was from 75 to 108 min. Heart rate, mean arterial pressure, cardiac index (CI) by pulse contour method, and systemic vascular resistance were measured before, during, and after tourniquet inflation. pH, PaO(2), PaCO(2), and lactate blood concentrations were also measured. VO(2) and VCO(2) were assessed every minute from tracheal intubation up to 15 min after tourniquet deflation and VO(2) in excess of the basal value over the 15 min after deflation (VO(2)exc) was calculated. Mean arterial pressure increased 26% (P: < 0.05) during inflation and returned to basal values after deflation. CI did not change immediately after inflation; although, thereafter, it increased 18% (P: < 0.05). Five minutes after deflation, CI further increased to a value 40% higher than the basal value. Therefore, systemic vascular resistance increased 20% suddenly after inflation (P: < 0.05) and decreased 18% after deflation (P: < 0.05). VO(2) and VCO(2) remained stable during inflation and increased (P: < 0.05) after deflation. VO(2)exc depended on duration of tourniquet inflation time (Tisch) (P: < 0.05). After deflation, PaCO(2) and lactate increased (P: < 0.05) while Tisch increased. We conclude that tourniquet application induces modifications of the cardiovascular system and metabolism, which depend on tourniquet phase and on Tisch. Whether these modifications could be relevant in patients with poor physical conditions is not known.

IMPLICATIONS

The clinical effects of tourniquet application were evaluated in 10 young men undergoing knee surgery. Our data indicate that tourniquet application causes hemodynamic and metabolic changes which may become clinically relevant after a long period of tourniquet inflation, particularly in patients with concomitant cardiovascular diseases.

Elective transumbilical compared with standard laparoscopic cholecystectomy

OBJECTIVE

To compare the transumbilical technique of laparoscopic cholecystectomy with standard laparoscopic cholecystectomy.

DESIGN

Randomised open study.

SETTING

Teaching hospital, Italy.

SUBJECTS

90 patients who required elective cholecystectomy under general anaesthesia.

INTERVENTIONS

Standard laparoscopic cholecystectomy through 4 ports or transumbilical cholecystectomy through 2 ports.

MAIN OUTCOME MEASURES

Amount of pain and analgesia, cost, side effects, and cosmesis.

RESULTS

25 patients were excluded from analysis (8 in the standard group because relevant data were not recorded; and 17 in the transumbilical group in 4 of whom relevant data were not recorded, and 13 for technical reasons). 32 patients who had standard, and 25 who had transumbilical cholecystectomy had operative cholangiograms. There were no complications, no side effects, and no conversions to open cholecystectomy. Those who had transumbilical cholecystectomy had significantly lower pain scores (p<0.05) and required significantly less analgesia during the first 24 hours (p<0.05) than those who had standard laparoscopic cholecystectomy.

CONCLUSION

Once the learning curve has been completed, transumbilical cholecystectomy is possible without some of difficulties associated with standard laparoscopic cholecystectomy.

Maintenance of and recovery from anaesthesia in elderly patients. A clinical comparison between sevoflurane and isoflurane

BACKGROUND

The goal of this multicenter, prospective, randomized clinical investigation was to compare the clinical efficacy and safety of sevoflurane and isoflurane during the maintenance of and the recovery from general anaesthesia in elderly patients.

METHODS

With the approval of the Ethical Committee and the patient informed consent, 104 ASA physical status II-III patients, aged more than 65 years, were randomized in order to receive either isofluorane (n = 54) or sevoflurane (n = 50) as the main general anaesthetic. After an oral diazepam (0.1-0.2 mg kg-1) and intramuscular atropine (0.007-0.01 mg kg-1) premedication, anaesthesia was induced intravenously and then maintained by adjusting the end-tidal concentrations of the inhalation agent for the maintainance of cardiovascular stability. At the moment of the last skin suture the inhalational agents were discontinued and the neuromuscular block was reversed. The following times were recorded: time of extubation, time of eyes opening, time of command response and readiness for discharge. The occurrence of untoward event throughout the study was also recorded. Before surgery and 24 hr after the procedure, blood was collected in order to assess renal function.

RESULTS

No differences in demography, duration of surgery, exposure to the volatile anaesthetic, and renal function laboratory values were observed between the two groups. The time of extubation (median: 8 min versus 11 min, p < 0.01), emergence (median: 8.5 min versus 12.5 min, p < 0.01), command response (median: 10 min versus 15.5 min, p < 0.01), and suitability for discharge from the recovery area (median: 21 min versus 27.5 min, p < 0.01) were shorter in the sevoflurane group than in the isoflurane one. The success rate (absence of any event) during induction and maintenance periods was better in sevoflurane than isoflurane group (p < 0.02 and p < 0.001, respectively). Hypotension (systolic arterial blood pressure decrease > 30% of baseline values) was observed in 16 patients receiving isoflurane (29%) and only in 5 patients receiving sevoflurane (10%) (p < 0.02).

DISCUSSION

When used in elderly patients undergoing operations of intermediate duration, sevoflurane provides a more rapid emergence from anaesthesia with a faster fulfillment of discharging criteria, and a more stable cardiovascular homeostasis than isoflurane. Renal function also appears to be equally well preserved with both anaesthetics.

[Non-invasive evaluation of cardic output by analysis of peripheral pressure profile in patients recovering in intensive care]

BACKGROUND

The analysis of the arterial pulse contour obtained by means of a non-invasive device (Finapres) seems to be an ideal method to measure cardiac output (CO). An individual calibration factor (Z) dimensionally equal to aortic impedence is the necessary pre-requisite to calculate CO by pulse contour analysis. To verify the reliability of non-invasive pulse contour method, we compared the COs measured from Finapres tracings with those measured from thermodilution method in Intensive Care patients.

METHODS

In 9 patients undergoing cardiac and general surgery, CO was measured from thermodilution (COTD) within 24 hours of postoperative period (total of 67 measurements). During COTD measurements, Finapres tracings were recorded and then analysed to calculate CO by two different procedures. In the former (COA), Z was calculated from an algorithm which takes into account heart rate, mean arterial pressure and age of the patient. In the latter procedure (COB), Z was experimentally determined from the initial COTD measure and then updated for the hemodynamic conditions of the patient.

RESULTS

COTD ranged between 3.5 and 9.5 L.min-1 (mean value 5.53 +/- 1.29 L.min-1). The mean difference between COTD e COA was 0.485 +/- 1.537 L.min-1 and the mean percentage error was 25.1 +/- 14.5%. The experimental determination of Z reduced the mean difference and the mean percentage error between thermodilution and Finapres method to--0.002 +/- 1.056 L.min-1 and 15.5 +/- 11.0%, respectively. The regression line between COTD and COB turned out to be: COB = 0.68 + 0.88.COTD (r = 0.73).

CONCLUSIONS

The pulse contour analysis applied to Finapres tracing allows to calculate CO with reasonable accuracy in the intensive care patients. An initial experimental determination of Z is recommended to improve the accuracy of Finapres method.

[Postoperative epidural analgesia]

Epidural analgesia with local anesthetics and opioids is one of the most effective methods for postoperative pain control. In critical patients it seems to improve outcome as well as pain control. This technique works better when started in the intraoperative time. Epidural analgesia is safe on surgical wards if nursing staff is trained in managing epidural catheters and in early detection and treatment of major and minor side effects. Nursing staff cooperates with the Acute Pain Service doctors and nurses who are on call on a 24 hour basis. Many perspective and retrospective studies showed a very low incidence of major side effects with epidurals. So we can consider it safe and effective even if we consider its invasiveness.

[Anesthesiologic problems in patients with Launois-Bensaude-Madelung disease. Clinical case]

Authors report a Launoise-Bensaude-Madelung disease case, in a 64 year old man, admitted to a Plastic Surgical Department for obesity, dysphonia, dysphagia, dyspnea. Early symptoms appeared 20 years before Hospital admission. Lipomatous tissue occupied nape, mandible, neck and shoulders. Surgical exeresis of lipomatous tissue under general anesthesia needed for the patient. Neck movements and mouth opening were short (Mallampati Score = 4); a neck computed tomography showed a tracheal compression and right displacement. Tracheal intubation was considered difficult or impossible. Nose-tracheal intubation was performed using a pediatric fiberoptic instrument as guide for a small gauge tracheal tube. Tracheal stenosis required many attempts for correct nose-tracheal intubation. Fiberoptic instrument as guide for tracheal tube can be useful for patients with Launoise-Bensaude-Madelung disease, when tracheal intubation is considered difficult or impossible. Knowledge of fiberoptic tracheal intubation techniques is mandatory for anesthesiologists, allowing tracheal intubation in patients with anatomical variations of mouth or upper respiratory airways.

The effect of laparoscopic cholecystectomy on cardiovascular function and pulmonary gas exchange

Hemodynamic changes, pulmonary CO2 elimination (VECO2) and gas exchange were evaluated during laparoscopic cholecystectomy. An algorithm to calculate inspired ventilation (VI) needed to maintain constant PaCO2 was also developed. In 12 ASA physical status I patients undergoing laparoscopic cholecystectomy, heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), and systemic vascular resistance index (SVRI) were measured by the analysis of a radial artery pressure profile before, during, and after CO2 insufflation. Alveolar-arterial oxygen pressure gradient (P(A-a)O2), physiological and alveolar ventilatory dead space fractions (VDphys/VT; VDalv/VT), and PaCO2 were measured as well. VECO2 was assessed every minute in the patients maintained in the head-up position. HR did not significantly change during pneumoperitoneum, whereas MAP showed a transient increase (24.9%; P < 0.05) after CO2 insufflation. CI remained stable during pneumoperitoneum, but increased (25.0%; P < 0.05) after deflation. As a consequence, SVRI transiently increased after CO2 insufflation and decreased by 15.8% (P < 0.05) 5 min after deflation. P(A-a)O2 increased slightly (P < 0.05) with increased anesthesia time. VDphys/VT and VDalv/VT did not change after pneumoperitoneum onset, but VDalv/VT decreased after CO2 deflation (13.4%; P < 0.05). VECO2 increased (decreased) after a monoexponential time course during (after) CO2 insufflation in 8 of 12 patients. The mean time constants (t) of the monoexponential functions were 26.3 and 15.4 min during and after pneumoperitoneum. A monoexponential time course was shown also by PaCO2 during CO2 insufflation (tau = 27.8 min). Finally, the VI needed to maintain PaCO2 at a selected value could be calculated by the following algorithm: VI = [0.448.(1-e(-t/tau) + 2.52].(VA.PaCO2.713)-1, where VA corresponds to alveolar ventilation and t must be chosen according to the pneumoperitoneum phase. We conclude that CO2 insufflation in the abdominal cavity does not induce significant changes in cardiopulmonary function in ASA physical status I patients. The algorithm proposed seems to be a useful tool for the anesthesiologists to maintain constant PaCO2 during all surgical procedures.

Preemptive analgesia: intraperitoneal local anesthetic in laparoscopic cholecystectomy. A randomized, double-blind, placebo-controlled study

BACKGROUND

A controversy exists over the effectiveness and clinical value of preemptive analgesia. Additional studies are needed to define the optimum intensity, duration, and timing of analgesia relative to incision and surgery.

METHODS

One hundred twenty patients undergoing laparoscopic cholecystectomy under general anesthesia plus topical peritoneal local anesthetic or saline were studied. Local anesthetic (0.5% bupivacaine with epinephrine) or placebo solutions were given as follows: immediately after the creation of a pneumoperitoneum (blocking before surgery), and at the end of the operation (blocking after surgery). Patients were randomly assigned to one of four groups of 30 patients each. Group A (placebo) received 20 ml 0.9% saline both before and after surgery, group B received 20 ml 0.9% saline before surgery and 20 ml local anesthetic after surgery, group C received 20 ml local anesthetic both before and after surgery, group P received 20 ml local anesthetic before and 20 ml 0.9% saline after surgery. Pain was assessed using a visual analog scale and a verbal rating scale at 0, 4, 8, 12, and 24 h after surgery. Metabolic endocrine responses (blood glucose and cortisol concentrations) and analgesic requirements also were investigated.

RESULTS

Pain intensity (visual analog and verbal rating scales) and analgesic requirements were significantly less in the group receiving bupivacaine after surgery compared to placebo. However, in the groups receiving bupivacaine before surgery, both pain intensity and analgesic consumption were less than in the group receiving bupivacaine only after surgery. Blood glucose and cortisol concentrations 3 h after surgery were significantly less in groups receiving bupivacaine before surgery.

CONCLUSIONS

The results indicate that intraperitoneal local anesthetic blockade administered before or after surgery preempts postoperative pain relative to an untreated placebo-control condition. However, the timing of administration is also important in that postoperative pain intensity and analgesic consumption are both lower among patients treated with local anesthetic before versus after surgery.

The effects of intraperitoneal local anesthetic on analgesic requirements and endocrine response after laparoscopic cholecystectomy: a randomized double-blind controlled study

This randomized double-blind placebo-controlled study was designed to evaluate the effects on postoperative pain of the local anesthetic, 0.5% bupivacaine with epinephrine, sprayed hepatodiaphragmatically under the surgeon's direct view during laparoscopic cholecystectomy. Metabolic endocrine responses to surgery (glucose and cortisol) and nonsteroidal anti-inflammatory drug requirements were investigated, as well as the presence of nausea, vomiting, and sweating. Local anesthetics or placebo solutions were given as follows. Immediately following the creation of a pneumoperitoneum, surgeons sprayed the first 20 mL of solution (S1), and an additional 20 mL of solution (S2) was sprayed at the end of the operation. Patients were classified into three groups (14 patients per group). Group A received 20 mL of saline during both S1 and S2, group B received 20 mL of saline during S1 and 20 mL of bupivacaine during S2, and group C received 20 mL of bupivacaine during both S1 and S2. The degree of postoperative pain was assessed using the visual analogue scale (VAS) and the verbal rating scale (VRS) on arrival in the recovery room and subsequently at time intervals of 4 h, 8 h, 12 h, and 24 h. The results of this study indicate a significant decrease of postoperative pain in patients treated with local anesthetic. VAS and VRS pain scores, as well as respiratory rate and analgesic requirements, were significantly lower in group C. The postoperative plasma cortisol level in group C was significantly lower than in groups A and B.

[Effects of age, body weight, and ventilatory pattern on the difference between arterial and end-tidal PCO2]

OBJECTIVE

To evaluate the effects of physiological ventilatory patterns on P(a-ET)CO2 gradient and on the alveolar dead space production during controlled mechanical ventilation.

DESIGN

Prospective and experimental comparison among three different ventilatory settings in three different groups of subjects.

SETTING

General surgery's operating-theatre in university hospital.

PATIENTS

Twenty-eight patients subdivided randomly in 3 groups differing for ventilatory setting. I group: constant tidal volume (VC = 8 ml.kg-1) and 3 different respiratory frequencies (f = 10, 12 and 14 breaths.min-1); II group: constant ventilation (112 ml.kg-1) but VC and f modified in three different ways; III group: inspiratory volume was set to give an end-tidal PCO2 (PETCO2) of about 35 mmHg. The cases were subdivided, on the basis of P(a-ET)CO2 distribution, in three groups: group with values larger than mean plus 1 standard deviation, group with values between +/- 1 standard deviation and group with values lower than mean minus 1 standard deviation. Moreover in two homogeneous groups for age.

INTERVENTIONS

General surgery but not important because measures were performed before surgical manoeuvres.

MEASUREMENTS AND MAIN RESULTS

Anthropometrical data (age and body weight), PaCO2, PETCO2, heart rate, invasive arterial pressure, ventilatory parameters and airway pressure were collected for every subject and ventilatory setting; arterial to end-tidal difference P(a-ET)CO2 and P(a-ET)CO2.PaCO2(-1) were calculated during data analysis. The P(a-ETFCO2 and P(a-ET)CO2.PaCO2(-1) values were not significantly different among the three different ventilatory patterns both in the first and in the second group. P(a-ET)CO2 values were significantly correlated with age, body weight and airway pressure. These parameters were correlated significantly also with P(a-ET)CO2.PaCO2(-1) values.

CONCLUSIONS

Ventilatory setting, used in a normal physiological range, don't affect P(a-ET)CO2 difference during mechanical ventilation. Age, body weight and airway pressure of the patient must be considered to obtain a correct value of PaCO2 by the measure of PETCO2.

[Effectiveness of regional anesthesia for loco-regional carotid surgery. Retrospective review of 147 interventions]

The Authors present a retrospective review that compares general anesthesia with regional anesthesia performed during carotid endarterectomy surgery. The study includes 147 procedures, performed on 144 patients: 76 had general anesthesia and 71 had regional anesthesia. After emphasizing the importance of conscience preservation during regional anesthesia to allow a simple and secure monitoring of the patient's neurologic functions, the Authors point out the decrease of peri- and postoperative accidents, whether neurologic or not, obtained with regional anesthesia. Another essential advantage of this technique is the possibility to insert the transitory shunt only when objectively necessary, ulteriorly reducing neurologic complications. Cervical plexus block is primarily indicated for high risk patients with instable neurologic simptomatology, severe stenosis of the contralateral carotid, coronary heart disease. The technique has proved to be of easy execution, safe and well accepted by the patient and the surgeon.

[The analgesic treatment of the surgical patient]

An effective treatment of postoperative pain can achieve a better postop course especially in high risk patients. Pain is unacceptable when it can be relieved and, beside all it causes vasoconstriction, hypertension, tachycardia, fluid retention and pulmonary hypoventilation. A correct use of both narcotic drugs and NSAIDs are sufficient in most cases. In high risk patients, mainly after thoracic and upper abdominal procedures, insertion of a peridural catheter for drug administration can be very useful. The authors discuss the therapeutic possibilities according mainly to their experience.

[Effects of extracorporeal circulation and hypothermia on cellular immune activity in patients undergoing heart surgery]

Aspecific cellular reactivity was assessed in patients who underwent open heart surgery. The authors conclude that depressed PMN activity measured as O2- production is not linked to anaesthesiological procedures, hemodilution and hypothermia. No conclusive reports are possible on the role of pulmonary reinfusion or plasmatic and cellular mechanism of depression.