Intraoperative effects of an alveolar recruitment manoeuvre in patients undergoing laparoscopic colon surgery

INTRODUCTION

Pulmonary atelectasis is common in patients undergoing laparoscopic abdominal surgery under general anaesthesia, which increases the risk of perioperative respiratory complications. Alveolar recruitment manoeuvres (ARM) are used to open up the lung parenchyma with atelectasis, although the duration of their benefit has not been clearly established. The aim of this study was to determine the effectiveness of an ARM in laparoscopic colon surgery, the duration of response over time, and its haemodynamic impact.

METHODS

Twenty-five patients undergoing laparoscopic colon surgery were included. After anaesthetic induction and initiation of surgery with pneumoperitoneum, an ARM was performed, and then optimal PEEP determined. Respiratory mechanics and gas exchange variables, and haemodynamic parameters, were analysed before the manoeuvre and periodically over the following 90 min.

RESULTS

Three patients were excluded for surgical reasons. The alveolar arterial oxygen gradient went from 94.3 (62.3-117.8) mmHg before to 60.7 (29.6-91.0) mmHg after the manoeuvre (P < .05). This difference was maintained during the 90 min of the study. Dynamic compliance of the respiratory system went from 31.3 ml/cmH2O (26.1-39.2) before the manoeuvre to 46.1 ml/cmH2O (37.5-53.5) after the manoeuvre (P < .05). This difference was maintained for 60 min. No significant changes were identified in any of the haemodynamic variables studied.

CONCLUSION

In patients undergoing laparoscopic colon surgery, performing an intraoperative ARM improves the mechanics of the respiratory system and oxygenation, without associated haemodynamic compromise. The benefit of these manoeuvres lasts for at least one hour.

Gastric herniation due to rupture of diaphragmatic prosthesis in the postoperative period of pleuropneumonectomy due to mesothelioma: A complication to consider

Extrapleural pneumonectomy, usually associated with pericardial and diaphragmatic reconstruction with prosthetic material, is one of the surgical techniques used in the treatment of malignant pleural mesothelioma. Herniation of the abdominal viscera towards the thorax through the prosthetic material at the diaphragmatic level is a rare but potentially serious complication of these procedures, which must be diagnosed quickly for urgent repair. We present the case of a patient who presented with gastric herniation in the early postoperative period of a left pneumonectomy due to pleural mesothelioma. The clinical findings were mild, but supported by imaging tests, they confirmed the diagnostic hypothesis and facilitated the solution of the condition. Possible contributing factors are reviewed and the need for early diagnosis and treatment is emphasized to avoid ischemia of herniated abdominal viscera in the thoracic cavity, due to the risk of necrosis and contamination by fecaloid material.

Critical patients COVID-19 has changed the management and outcomes in the ICU after 1 year of the pandemic? A multicenter, prospective, observational study

OBJECTIVE

To compare the clinical characteristics, treatments, and evolution of critical patients with COVID-19 pneumonia treated in Intensive Care Units (ICU) after one year of pandemic.

METHODOLOGY

Multicenter, prospective study, which included critical COVID-19 patients in 9 ICUs in northwestern Spain. The clinical characteristics, treatments, and evolution of patients admitted to the ICU during the months of March-April 2020 (period 1) were compared with patients admitted in January-February 2021 (period 2).

RESULTS

337 patients were included (98 in period 1 and 239 in period 2). In period 2, fewer patients required invasive mechanical ventilation (IMV) (65% vs 84%, p < 0.001), using high-flow nasal cannulas (CNAF) more frequently (70% vs 7%, p < 0.001), ventilation non-invasive mechanical (NIMV) (40% vs 14%, p < 0.001), corticosteroids (100% vs 96%, p = 0.007) and prone position in both awake (42% vs 28%, p = 0.012), and intubated patients (67% vs 54%, p = 0.034). The days of IMV, ICU stay and hospital stay were lower in period 2. Mortality was similar in the two periods studied (16% vs 17%).

CONCLUSIONS

After 1 year of pandemic, we observed that in patients admitted to the ICU, CNAF, NIMV, use of the prone position, and corticosteroids have been used more frequently, reducing the number of patients in IMV, and the length of stay in the ICU and hospital stay. Mortality was similar in the two study periods.

[Critical patients COVID-19 has changed the management and outcomes in the ICU after 1 year of the pandemic? A multicenter, prospective, observational study]

Objective

To compare the clinical characteristics, treatments, and evolution of critical patients with COVID-19 pneumonia treated in intensive care units (ICU) after one year of pandemic.

Methodology

Multicenter, prospective study, which included critical COVID-19 patients in 9 ICUs in northwestern Spain. The clinical characteristics, treatments, and evolution of patients admitted to the ICU during the months of March-April 2020 (period 1) were compared with patients admitted in January-February 2021 (period 2).

Results

337 patients were included (98 in period 1 and 239 in period 2). In period 2, fewer patients required invasive mechanical ventilation (IMV) (65% vs. 84%, P < .001), using high-flow nasal cannulas (CNAF) more frequently (70% vs. 7%, P < .001), ventilation non-invasive mechanical (NIMV) (40% vs. 14%, P < .001), corticosteroids (100% vs. 96%, P = .007) and prone position in both awake (42% vs. 28%, P = .012), and intubated patients (67% vs. 54%, P = .034). The days of IMV, ICU stay and hospital stay were lower in period 2. Mortality was similar in the two periods studied (16% vs. 17%).

Conclusions

After one year of pandemic, we observed that in patients admitted to the ICU, CNAF, NIMV, use of the prone position, and corticosteroids have been used more frequently, reducing the number of patients in IMV, and the length of stay in the ICU and hospital stay. Mortality was similar in the two study periods.

Postoperative lactate elevation as a marker of underlying acute mesenteric ischemia. Description of two cases

Serum lactate is a non-specific marker of tissue hypoperfusion. Elevated serum lactate is used in the differential diagnosis of acute intestinal ischemia. Although this practice is controversial, in the absence of other validated markers lactate is still used because of its high sensitivity. We present the cases of two patients who developed acute mesenteric ischemia as a post-surgical complication. The patients reported moderate abdominal pain -a non-specific symptom in the postoperative context- and tests showed progressively increasing serum lactate levels, which facilitated suspicion and subsequent diagnostic confirmation through an imaging test. These cases highlight the physiopathological importance of lactate elevation in the perioperative context and of performing a differential diagnosis of its possible causes, including mesenteric ischemia. Although the outcome was negative in the first case, early suspicion allowed us to make an effective diagnosis and administer appropriate treatment in the second patient.

Postoperative lactate elevation as a marker of underlying acute mesenteric ischemia. Description of two cases

Serum lactate is a non-specific marker of tissue hypoperfusion. Elevated serum lactate is used in the differential diagnosis of acute intestinal ischemia. Although this practice is controversial, in the absence of other validated markers lactate is still used because of its high sensitivity. We present the cases of two patients who developed acute mesenteric ischemia as a post-surgical complication. The patients reported moderate abdominal pain -a non-specific symptom in the postoperative context- and tests showed progressively increasing serum lactate levels, which facilitated suspicion and subsequent diagnostic confirmation through an imaging test. These cases highlight the physiopathological importance of lactate elevation in the perioperative context and of performing a differential diagnosis of its possible causes, including mesenteric ischemia. Although the outcome was negative in the first case, early suspicion allowed us to make an effective diagnosis and administer appropriate treatment in the second patient.

Late bilateral vocal cord palsy following endotracheal intubation due to COVID-19 pneumonia

Vocal cord paralysis is a rare but severe complication after orotracheal intubation. The most common cause is traumatic, due to compression of the recurrent laryngeal nerve between the orotracheal tube cuff and the thyroid cartilage. Other possible causes are direct damage to the vocal cords during intubation, dislocation of the arytenoid cartilages, or infections, especially viral infections. It is usually due to a recurrent laryngeal nerve neuropraxia, and the course is benign in most patients. We present the case of a man who developed late bilateral vocal cord paralysis after pneumonia complicated with respiratory distress due to SARS-CoV-2 that required orotracheal intubation for 11 days. He presented symptoms of dyspnea 20 days after discharge from hospital with subsequent development of stridor, requiring a tracheostomy. Due to the temporal evolution, a possible contribution of the SARS-CoV- 2 infection to the picture is pointed out.

National survey on thromboprophylaxis and anticoagulant or antiplatelet management in neurosurgical and neurocritical patients

OBJECTIVES

To determine the protocols used by Spanish anaesthesiologists for thromboprophylaxis and anticoagulant or antiplatelet drugs management in neurosurgical or neurocritical care patients.

MATERIAL AND METHODS

An online survey with 22 questions, with one or multiple options, launched by the Neuroscience Subcommittee of the Spanish Anaesthesia Society and available between June and October 2012.

RESULTS

Of the 73 hospitals included in the National Hospitals Catalogue, a valid response to the online questionnaire was received by 41 anaesthesiologists from 37 sites (response rate 50.7%). Only one response per site was used. A specific protocol was available in 27% of these centres. Mechanical thromboprophylaxis is used, intraoperatively or postoperatively, in 80%, and pharmacological treatment is used by 75% of respondents. Enoxaparin was the most frequent heparin used in craniotomy patients (78%). Craniotomies were performed maintaining acetylsalicylic acid treatment in patients with coronary stents and double anti-platelet treatment in a half of the centres.

CONCLUSIONS

Mechanical thromboprophylaxis is used more frequently than the pharmacological approach in neurosurgical or neurocritical populations in Spanish hospitals. Management of patients under previous anticoagulant treatment was highly heterogeneous among hospitals included in this survey. Previous antiplatelet treatment is modified depending on primary or secondary prescription.

[Detection of a cerebral ischaemia episode during surgery by monitoring the brain tissue oxygen pressure]

The detection and treatment of cerebral ischaemia and tissue hypoxia for the prevention of secondary injury are the basic objectives during anaesthesia for neurosurgical procedures. The monitoring of the tissue oxygen pressure is direct and can enable potentially harmful situations to be detected in real time. Although it was initially used in neurocritical patients, its use has extended to surgical patients. We present the case of a patient subjected to surgical resection of a dural arteriovenous fistula in which the brain tissue oxygen pressure around the area of the lesion was monitored. The finding of an episode of cerebral tissue hypoxia during closure of the craniotomy determined the treatment of the patient. We highlight the possible use of this neuromonitoring for the rapid detection of regional cerebral hypoxia events in the peri-operative period of vascular neurosurgery, procedures that have a significant risk of, mainly ischaemic, hypoxia episodes.

[Questionnaire on the anaesthesiology treatment of patients subjected to posterior fossa neurosurgery]

OBJECTIVES

To find out, by means of a questionnaire, the procedures used by Spanish anaesthetists in peri-operative management of patients subjected to neurosurgery of the posterior cranial fossa.

MATERIAL AND METHODS

A closed-question type questionnaire was sent to Anaesthesiology Departments with a Neurosurgery Department on the participation of anaesthetists in the peri-operative treatment of patients subjected posterior fossa surgery.

RESULTS

The questionnaire was completed by 42 (57.5%) of the 73 national public hospitals with a Neurosurgery Department. The posterior fossa surgery was performed in the sitting position in 36 hospitals, although it was less frequently used than the lateral decubitus or prone decubitus position. There was little specific neurological monitoring, as well as little use of precordial and/or transcranial Doppler for detecting vascular air embolism. Nitrous oxide was used in less than 10% of the centres, and 15% avoided neuromuscular block when neurophysiological monitoring was used during the surgery. Cardiovascular problems were mentioned as being the most frequent in 29% of the centres, while in the post-operative period the most common complications were, cranial nerve déficit, airway oedema (23%), and post-operative vomiting (47%).

CONCLUSIONS

The results obtained from the questionnaire showed that the sitting position was less used than the prone position in posterior fossa surgery, and that neurophysiological monitoring is during surgery is hardly used.

[The role of recombinant activated factor VII in neuro- surgical and neurocritical patients]

Central nervous system haemorrhage is a severe pathology, as a small amount of bleeding inside the brain can result in devastating consequences. Haemostatic agents might decrease the consequences of intra- cranial bleeding, whichever spontaneous, traumatic, or anticoagulation treatment etiology. Proacogulant recombinant activated factor VII (rFVIIa) has been given after central nervous system bleeding, with an off-label indication. In this update, we go over the drug mechanism of action, its role in the treatment of central nervous system haemorrhage and the published evidences regarding this subject. We carried out a literature review concerning the treatment with rFVIIa in central nervous system haemorrhage, neurocritical pathologies and neurosurgical procedures, searching in MEDLINE and in clinical trials registry: http://clinicaltrials.gov (last review September 2010), as well as performing a manual analysis of collected articles, looking for aditional references. The results of randomized clinical trials do not support the systematic administration of rFVIIa for spontaneous intracranial cerebral haemorrhage. In other central nervous system related haemorrhages, the current available data consist on retrospective studies, expert opinion or isolated case reports.

[Neuroanesthesia for embolization of a ruptured cerebral aneurysm: clinical practice guidelines]

When the neuroanesthesia working group of the Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor surveyed Spanish anesthesiologists to learn the degree of their involvement in the diagnosis and treatment of spontaneous subarachnoid hemorrhage, a surprising finding was that anesthetists did not participate in endovascular repair of intracranial aneurysms when the procedure was carried out in an interventional radiology department. These interventions, which are considered minimally invasive and are performed outside the operating room, are not risk-free. Based on the survey results and a systematic review of the literature, the working group has provided practice guidelines for the perioperative management of anesthesia for endovascular repair of ruptured cerebral aneurysms. In our opinion, the diversity of practice in the hospitals surveyed calls for the application of practice guidelines based on consensus if we are to reduce variability in clinical and anesthetic approaches as well as lower the rates of morbidity and mortality and shorten the hospital stay of patients undergoing exclusion of an aneurysm.

[Neuroanesthetic management for surgical clipping of a ruptured cerebral aneurysm: clinical practice guidelines]

Subarachnoid hemorrhage due to spontaneous rupture of a cerebral aneurysm is associated with high rates of morbidity and mortality and requires multidisciplinary treatment. The debate on surgical vs endovascular treatment continues, although short-term clinical outcomes and survival rates are better after endovascular treatment. In Spain, a strong trend toward reduced use of clipping has been noted, and neuroanesthetists are less often called on to provide anesthesia in this setting. Our intervention, however, can be decisive. The neuroscience working group of the Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor has developed guidelines for managing anesthesia in these procedures. Based on a national survey and a systematic review of the literature, the recommendations emphasize the importance of ensuring appropriate intracranial conditions, treating complications, and taking steps to protect against cerebral hemorrhage.

[Neurologic complications of subarachnoid hemorrhage due to intracranial aneurysm rupture]

The high rates of morbidity and mortality after subarachnoid hemorrhage due to spontaneous rupture of an intracranial aneurysm are mainly the result of neurologic complications. Sixty years after cerebral vasospasm was first described, this problem remains unsolved in spite of its highly adverse effect on prognosis after aneurysmatic rupture. Treatment is somewhat empirical, given that uncertainties remain in our understanding of the pathophysiology of this vascular complication, which involves structural and biochemical changes in the endothelium and smooth muscle of vessels. Vasospasm that is refractory to treatment leads to cerebral infarction. Prophylaxis, early diagnosis, and adequate treatment of neurologic complications are key elements in the management of vasospasm if neurologic damage, lengthy hospital stays, and increased use of health care resources are to be avoided. New approaches to early treatment of cerebral lesions and cortical ischemia in cases of subarachnoid hemorrhage due to aneurysm rupture should lead to more effective, specific management.

[Systemic complications of subarachnoid hemorrhage from spontaneous rupture of a cerebral aneurysm]

Systemic complications secondary to subarachnoid hemorrhage from an aneurysm are common (40%) and the mortality attributable to them (23%) is comparable to mortality from the primary lesion, rebleeding, or vasospasm. Although nonneurologic medical complications are avoidable, they worsen the prognosis, lengthen the hospital stay, and generate additional costs. The prevention, early detection, and appropriate treatment of systemic complications will be essential for managing the individual patient's case. Treatment should cover major symptoms (headache, nausea, and dizziness) and ambient noise should be reduced, all with the aim of achieving excellence and improving the patient's perception of quality of care.

[Subarachnoid hemorrhage: epidemiology, social impact and a multidisciplinary approach]

Cerebrovascular disease, whether ischemic or hemorrhagic, is a worldwide problem, representing personal tragedy, great social and economic consequences, and a heavy burden on the health care system. Estimated to be responsible for up to 10% of mortality in industrialized countries, cerebrovascular disease also affects individuals who are still in the workforce, with consequent loss of productive years. Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident that leads to around 5% of all strokes. SAH is most often due to trauma but may also be spontaneous, in which case the cause may be a ruptured intracranial aneurysm (80%) or arteriovenous malformation or any other abnormality of the blood or vessels (20%). Although both the diagnosis and treatment of aneurysmal SAH has improved in recent years, related morbidity and mortality remains high: 50% of patients die from the initial hemorrhage or later complications. If patients whose brain function is permanently damaged are added to the count, the percentage of cases leading to severe consequences rises to 70%. The burden of care of patients who are left incapacitated by SAH falls to the family or to private and public institutions. The economic cost is considerable and the loss of quality of life for both the patient and the family is great. Given the magnitude of this problem, the provision of adequate prophylaxis is essential; also needed are organizational models that aim to reduce mortality as well as related complications. Aneurysmal SAH is a condition which must be approached in a coordinated, multidisciplinary way both during the acute phase and throughout rehabilitation in order to lower the risk of unwanted outcomes.

[Perioperative treatment of a man receiving a left-lung transplant combined with coronary revascularization without use of extracorporeal circulation: with a brief review of pathophysiology and the literature]

Patients with significant coronary artery disease were once traditionally rejected as candidates for lung transplants because of higher risk of morbidity and mortality. We report the case of a man who received a left lung transplant and coronary revascularization without extracorporeal circulation in a combined surgical procedure after being diagnosed with significant coronary disease during the preoperative study for acceptance as a candidate for lung transplantation. We review the history of such combination procedures, which are changing clinicians' attitudes as to appropriate therapeutic approaches to take for complex patients. We also discuss the possible advantages of performing surgery without extracorporeal circulation. To our knowledge, this is the first report of a combined procedure that took place in a Spanish hospital.

[Fraudulent pain research: a hurt so deep nothing can alleviate it]

Untruthfulness in research is reprehensible. Dr Scott S. Reuben, an anesthesiologist at Baystate Medical Center in Springfield, Massachusetts in the United States, a leader and pioneer in the field of multimodal analgesia, has been accused of fraud, specifically of having falsified results in at least 21 manuscripts published over a period of 15 years. This may come to be seen as one of the largest-scale and longest-running acts of medical research fraud ever. Apart from fabricated data, it seems the author committed other acts of misconduct. His coauthors have not been accused of wrongdoing, as they allege their names were falsely appended to the manuscript. The editors of the 2 most implicated journals, Anesthesiology and Anesthesia & Analgesia, have published editorials retracting the papers they judge to be fraudulent. Because Dr Reuben is a major figure in postoperative multimodal analgesia, many studies by other authors whose hypotheses have emerged from findings announced in the discredited papers may also now be considered contaminated by association. The definitions of scientific misconduct and the procedures for pursuing offenders vary greatly from country to country, creating a certain degree of uncertainty about how to proceed when we confront this problem. Beyond any possible legal liability that might arise, there are the questions of how fraud might affect patients' health or the medical knowledge base. Although the concept of multimodal analgesia may continue to be defended, we cannot be absolutely sure of its benefits without carrying out new clinical trials to repair the damage done by this act of misconduct.

[Survey of anesthesiologists' practice in treating spontaneous aneurysmal subarachnoid hemorrhage]

OBJECTIVES

To evaluate the participation of Spanish anesthesiology departments in the management of patients hospitalized for spontaneous aneurysmal subarachnoid hemorrhage.

MATERIAL AND METHODS

Chiefs of anesthesiology departments of hospitals listed in the Spanish National Catalog of Hospitals of the Ministry of Health and Consumer Affairs were sent a questionnaire with 30 items covering protocols for the management of patients with spontaneous aneurysmal subarachnoid hemorrhage. Items asked about the participation of anesthesiologists during both admission and the perioperative period.

RESULTS

The questionnaire was sent to 132 hospitals, of which 18 (13.6%) responded. Forty-six percent of anesthesiology departments do not participate in the initial resuscitation. Only 4 reported having a protocol for treating these patients. The initial diagnosis was reportedly made by cranial computed tomography in all cases. Endovascular treatment was the most common procedure reported (66%) and it was given within the first 48 hours (66%). Basic monitoring was used more than nervous system monitoring. Total intravenous anesthesia was used for craniotomy in 53% of the hospitals and for endovascular treatment in 64%. Complications reported most often were vasospasm (100%) and hydrocephalus (69%).

CONCLUSIONS

Even though few questionnaires were returned, the results reveal scarce use of protocols for the treatment of spontaneous aneurysmal subarachnoid hemorrhage by anesthesiologists. It was also evident that the participation of anesthesiology department staff in the treatment of this condition takes place almost exclusively in the intraoperative period and that the use of nervous system monitoring is scarce. Endovascular treatment is increasing in our practice settings.

[Sedation in surgical procedures using regional anesthesia in adult patients: results of a survey of Spanish anesthesiologists]

OBJECTIVE

To analyze the frequency and methods of sedation used in the context of regional anesthesia in adults by means of a national survey.

MATERIAL AND METHODS

We carried out a survey of participants at the courses of an anesthesiology training organization (Fundación Europea de Enseñanza en Anestesiología), held in Spain in 2006. The survey questionnaires asked about indications for sedation used during surgery under regional anesthesia as well as the form of administration, follow-up, and complications.

RESULTS

A total of 375 questionnaires were sent out and 185 responses were received (49.3%). Sedation is always used to accompany regional anesthesia by 69.2% of the respondents; 13.5% of them discuss the technique to be used with the patient and come to an agreement. The same type of sedation, regardless of the regional block performed, is used by 49.2% of respondents, and 64.3% use a scale to evaluate the level of sedation. The most favored sedation technique is continuous infusion, followed by target controlled infusion and boluses on demand. The most commonly used technique is sedation with bolus injections. Sixty percent use a single agent and 38.9% use combinations. The most commonly reported adverse effects are variability of patient response (53.5%) and respiratory complications (27%). In cases of ineffective regional blockade, 49.2% of those surveyed switch to general anesthesia.

CONCLUSIONS

Sedation is very often used to complement regional anesthesia in adult patients. Even though continuous infusion is considered to be the most appropriate form of administration, the most commonly used form is injection of boluses. Sedation with a single drug is used more frequently than drug combinations. Variability of individual response is the complication most commonly reported by the respondents.

[Haloperidol or droperidol with dexamethasone for antiemetic prophylaxis in laparoscopic cholecystectomy]

OBJECTIVES

To compare haloperidol to droperidol, both with dexamethasone, for antiemetic prophylaxis in elective laparoscopic cholecystectomy.

MATERIAL AND METHODS

Prospective, randomized double-blind trial enrolling 75 ASA 1-2 patients who received anesthesia with propofol and remifentanil. After induction, 8 mg of intravenous dexamethasone was administered. After surgery, depending on group assignment, patients received 10 microg x kg(-1) of intravenous haloperidol (n = 25), 10 microg x kg(-1) of droperidol (n = 25), or physiologic saline solution (n = 25). Outcomes recorded were episodes of nausea or vomiting in the postoperative period (first 6 hours and/or 6-24 hours), requirement for antiemetic agents, morphine consumption, pain assessed on a visual analog scale, level of sedation, and adverse effects.

RESULTS

Five patients in the haloperidol group, 6 in the droperidol group, and 13 in the control group experienced an episode of nausea or vomiting in the 24-hour postoperative period (P < .05 between the active treatment groups and the control group). One patient in the haloperidol group, 6 in the droperidol group, and 8 in the control group reported nausea in the first 6 hours (P < .05). Three patients in the haloperidol group, 1 in the droperidol group, and 8 in the control group reported nausea in the later postoperative period (6-24 hours) (P < .05, droperidol vs control). Three patients in the haloperidol group, 1 in the droperidol group, and 7 in the control group experienced late vomiting (P < .05, droperidol vs control).

CONCLUSIONS

Either haloperidol or droperidol in combination with dexamethasone is more effective than dexamethasone alone for antiemetic prophylaxis after laparoscopic cholecystectomy.

Less postoperative nausea and vomiting after propofol + remifentanil versus propofol + fentanyl anaesthesia during plastic surgery

BACKGROUND

The effect of different opioids on postoperative nausea and vomiting (PONV) has not been conclusively determined yet, thus the aim of this study was to compare the incidence of PONV in propofol-anaesthetized patients receiving either fentanyl or remifentanil as opioid supplement.

METHODS

Sixty ASA physical status I and II patients scheduled for plastic surgery gave their written informed consent for this prospective, randomized, double-blind study. Anaesthesia was induced with propofol, rocuronium and fentanyl (n = 30; 2 microg kg(-1)) or remifentanil (n = 30; 1 microg kg(-1)). After tracheal intubation, anaesthesia was maintained with propofol, oxygen in air and an infusion of the opioid studied, which was modified according to clinical criteria. Baseline postoperative analgesia was achieved with intravenous propacetamol + metamizol. Intravenous morphine was given if visual analogic scale (VAS) for pain was > or = 4 (scale 0-10) and metoclopramide was administered if a patient presented > or = 2 PONV episodes (nausea or vomiting) in less than 30 min. Postoperatively (2, 12 and 24 h), we registered VAS, rescue morphine consumption, number of patients with episodes of PONV and number of patients requiring metoclopramide. P < 0.05 was considered significant.

RESULTS

There were no significant differences between groups in the demographic parameters, ASA physical status, propofol dose, VAS, and rescue morphine requirements. Fourteen patients in the fentanyl group and four in the remifentanil group presented PONV episodes 2-12 h postoperative hours' interval; (P < 0.05). Ten patients in the fentanyl group and four in the remifentanil group presented vomiting episodes in the same period (P < 0.05); and eight patients in the fentanyl group and one in the remifentanil group required metoclopramide; (P < 0.05). The number of postoperative PONV episodes were low, both in the 0-2-h period (n = 2 vs. n = 1, fentanyl and remifentanil, respectively) and in the 12-24-h period (n = 3 vs. n = 1).

CONCLUSION

Propofol + fentanyl anaesthesia resulted in a higher incidence of PONV and requirements of antiemetic drugs in the period between 2 and 12 postoperative hours compared with propofol + remifentanil, in patients undergoing plastic surgery.

[Fat embolism syndrome after surgery to replace the femoral stem of a hip prosthesis]

A 66-year-old woman developed hemodynamic instability, oliguria, prostration, fever, and coagulopathy 4 hours after surgery to replace the femoral stem component of a hip prosthesis under a combined subarachnoid-epidural block. Dyspnea and tachypnea developed, and a petechial rash appeared 24 hours later. The diagnosis was fat embolism after other possible causes were ruled out. Supplementary oxygen, fluid replacement therapy, and inotropic support were started. The patient's condition improved and she was discharged from the postoperative recovery unit 5 days after admission. Although fat embolism usually appears in young men after large bone fractures, it should be considered when symptoms consistent with this diagnosis arise in patients who have undergone orthopedic surgery so that appropriate treatment can be started early.

[Fentanyl or remifentanil to potentiate a single dose of rocuronium in patients anesthetized with propofol with evaluation by accelerometry]

OBJECTIVE

To compare the increase in potency of a single dose of rocuronium during anesthesia with propofol combined with either fentanyl or remifentanil.

PATIENTS AND METHODS

Forty patients scheduled for plastic surgery were distributed in 2 groups of 20 according to the opioid drug assigned: fentanyl or remifentanil. Induction with propofol was accomplished by computer-controlled infusion, with response measured in the adductor pollicis muscle. After calibration, a dose of 0.6 mg/Kg of rocuronium was infused. Anesthesia was maintained with propofol, oxygen in air, and an equipotent dose of either fentanyl or remifentanil, which was modified to maintain heart rate and systolic arterial pressure within 30% above or below baseline levels. Patient characteristics recorded were age, sex, height, weight, ASA class, type of surgery, and the propofol and opioid doses consumed. Intubation conditions and time to onset of action of rocuronium (T1), of recovery of the first response in a train of four (RT1), and of recovery of 25% of the first response or clinical duration.

RESULTS

The groups were statistically similar in terms of demographic variables, type of surgery, propofol and opioid consumption, intubation conditions, and rocuronium T1 and RT1. Clinical duration of anesthesia was longer (p<0.05) in the remifentanil group (33.1 +/- 10 minutes) than in the fentanyl group (27.1 +/- 7.4 minutes).

CONCLUSIONS

Remifentanil administered in combination with propofol for anesthesia does not affect time of onset of a single dose of 0.6 mg/Kg dose of rocuronium, but clinical duration of anesthesia is longer with remifentanil and propofol than with the fentanyl and propofol combination. The surgical and intubation conditions achieved with both combinations are adequate and similar.

[Hypertriglyceridemic pancreatitis and pregnancy]

A 33-year-old secundipara with a history of gestational diabetes and familial hypertriglyceridemia exacerbated during her previous pregnancy was admitted in the 36th week of gestation with diffuse abdominal pain, vomiting, low-grade fever, and general malaise. A blood sample had a lipemic, milky-pink appearance and plasma concentrations were as follows: triglycerides 2173 mg/dL, cholesterol 320 mg/dL, amylase 801 U/L, lactate dehydrogenase 650 U/L, creatinine 1.5 mg/dL, glucose 380 mg/dL, and left-shifted white cells. Acute pancreatitis was diagnosed and owing to signs of fetal distress, a cesarean was performed under light general anesthesia with propofol, succinylcholine, and sevoflurane. After the umbilical cord was cut, rocoronium and fentanyl were administered. The neonate was healthy and the patient's condition evolved favorably with conservative treatment. The incidence of pancreatitis during pregnancy is low but related morbidity and mortality are high. The usual cause is biliary tract disease, although rare metabolic alterations such as hyperlipidemia may occasionally act as the trigger. Early diagnosis and treatment are the keys to successful surgery and postoperative recovery.

The effects of isoflurane and desflurane on intracranial pressure, cerebral perfusion pressure, and cerebral arteriovenous oxygen content difference in normocapnic patients with supratentorial brain tumors

BACKGROUND

Desflurane is a volatile anesthetic agent with low solubility whose use in neurosurgery has been debated because of its effect on intracranial pressure and cerebral blood flow. The purpose of this study was to determine the variations on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) as well as on cerebral arteriovenous oxygen content difference (AVDo(2)) in normocapnic patients scheduled to undergo removal of supratentorial brain tumors with no evidence of mass effect during anesthesia with isoflurane or desflurane.

METHODS

In 60 patients scheduled to undergo craniotomy and removal of supratentorial brain tumors with no evidence of midline shift, anesthesia was induced with intravenous fentanyl, thiopental, and vecuronium and was maintained with 60% nitrous oxide in oxygen. Patients were assigned to two groups randomized to receive 1 minimum alveolar concentration isoflurane or desflurane for 30 min. Heart rate, mean arterial pressure, intraparenchymal ICP, and CPP were monitored continuously. Before and after 30 min of continuous administration of the inhaled agents, AVDo(2) was calculated.

RESULTS

There were no significant differences between groups in heart rate, mean arterial pressure, ICP, and CPP. ICP measurements throughout the study did not change within each group compared to baseline values. Mean arterial pressure decreased significantly in all patients compared to baseline values, changing from 105 +/- 14 mmHg (mean +/- SD) to 85 +/- 10 mmHg in the isoflurane group and from 107 +/- 11 mmHg to 86 +/- 10 mmHg in the desflurane group (P < 0.05 in both groups). CPP also decreased within each group compared with baseline values, changing from 95 +/- 15 mmHg to 74 +/- 11 mmHg in the isoflurane group and from 95 +/- 16 mmHg to 74 +/- 10 mmHg in the desflurane group (P < 0.05 in both groups). Cerebral AVDo(2) decreased significantly in both groups throughout the study, changing from 2.35 +/- 0.77 mm to 1.82 +/- 0.61 mm (mmol/l) in the isoflurane group (P < 0.05) and from 2.23 +/- 0.72 mm to 1.94 +/- 0.76 mm in the desflurane group (P < 0.05), without differences between groups.

CONCLUSIONS

The results of this study indicate that there are no variations on ICP in normocapnic patients undergoing removal of supratentorial brain tumors without midline shift, as they were anesthetized with isoflurane or desflurane. CPP and cerebral AVDo(2) decreased with both agents.

[Transfusion needs during intraoperative and immediate postoperative periods in arthroplasty of the hip and knee]

OBJECTIVES

To determine the factors associated with immediate perioperative transfusion requirements of hip or knee arthroplasty patients who have not been enrolled in a blood salvage program.

PATIENTS AND METHODS

This prospective study collected demographic (age, sex, weight, height, etc.), physiological (hemoglobin levels, coagulation times, preoperative platelet counts, etc.), clinical history and anesthetic and surgical data (type of anesthesia, surgical diagnosis, duration of procedure) in 112 patients undergoing orthopedic surgery: 19 cases of primary knee arthroplasty, 77 cases of hip arthroplasty and 16 replacements of hip arthroplasty. Logistic regression analysis of the aforementioned variables was performed to search for factors related to transfusional needs during and after hip arthroplasty or after knee arthroplasty, which was performed with a tourniquet applied to render intraoperative transfusion unnecessary.

RESULTS

The variables that increased the risk of transfusion during surgery were duration of procedure exceeding 120 min (OR 15.24; p = 0.01) and loss of over 500 ml of blood during surgery (OR 11.4; p = 0.02). The variables associated with perioperative transfusion were loss of over 500 ml in the postanesthetic recovery room (OR 12.6; p < 0.0001), hypotensive episodes during recovery (OR 11.7; p = 0.0001), prosthetic replacement (OR 6.33; p = 0.005), height < 160 cm (OR 5.03; p = 0.02), preoperative hemoglobin level < 13.5 g/dl (OR 4.97; p = 0.02), and surgery for reasons other than osteoarthritis (arthritis, pathological fractures, etc.) (OR 4.60; p = 0.04). Variables associated with transfusion of over two units of packed red cells were a history of neoplastic disease unrelated to arthroplasty (OR 378.67; p = 0.005), prosthetic replacement (OR 49.71; p = 0.009), diabetes (OR 36.49; p = 0.02) and a hypotensive event while in the postanesthetic recovery room (OR 29.12; p = 0.02).

CONCLUSION

These results suggest that certain modifiable factors increase the risk of blood transfusion in knee and hip arthroplasty. Specifically, they are duration of surgery, intra- and postoperative bleeding, preoperative hemoglobin level and instances of perioperative hypotension. Other factors outside our control are height or patient clinical history.

[Ventilation in prone decubitus in a patient with respiratory distress during heart surgery]

Acute respiratory failure and adult respiratory distress syndrome are serious complications after heart surgery and are associated with a high mortality rate. We report the case of a 50-year-old man who developed severe respiratory distress after heart surgery with extracorporeal circulation and for whom oxygenation was possible with ventilation in prone decubitus position only after other therapeutic measured had failed. The physiological bases of ventilation in prone decubitus position, as well as the indications and contraindications of the technique are discussed. Early treatment, which is fundamental for managing these patients, facilitates a favorable outcome as is illustrated by the case we report.

[Preloading with 500 ml of Hartmann's solution lessens the incidence and severity of hypotension and reduces the need for ephedrine after epidural anesthesia in ambulatory patients]

INTRODUCTION

Fluid preloading to prevent hypotension after epidural anesthesia has been widely questioned, although few studies have been performed in outpatients.

OBJECTIVE

To evaluate the incidence and severity of hypotension, and the need for vasoactive agents after epidural anesthesia in outpatients who did or did not receive fluid preloading.

PATIENTS AND METHODS

Forty patients under 55 years of age (ASA I and II) undergoing general surgery on an outpatient basis were assigned randomly to two groups of 20 according to whether they were to receive loading with Hartmann's solution or not before epidural anesthesia. All received a similar epidural dose of 2% mepivacaine. Hypotension was defined as a decrease of 20% in systolic or mean blood pressure in comparison with baseline, or absolute pressures of < 90 and 60 mmHg, respectively. Hypotension was treated with 5 mg boluses of ephedrine.

RESULTS

Fourteen patients in the non-preloading group and 5 in the preloading group developed hypotension (p < 0.05). Hypotensive episodes were fewer in patients receiving preloading fluids (0.5 +/- 1.2 versus 2.0 +/- 2.4; p < 0.05). The ephedrine dose required was higher in non-preloaded patients than in preloaded ones (10.0 +/- 12.2 versus 2.6 +/- 6.3 mg; p < 0.05). Time until presentation of hypotension was longer for non-preloaded patients.

CONCLUSIONS

For patients undergoing outpatient surgery, fluid preloading with 500 ml of Hartman's solution decreases both the incidence and severity of hypotension, as well as the need for vasoactive drugs after epidural anesthesia.

[Prolonged neuromuscular block after a single dose of vecuronium in a patient with undiagnosed polyneuropathy and steroid myopathy]

We report the case of a patient who had been receiving long-term corticoid therapy with undiagnosed polyneuropathy and steroid-related myopathy before experiencing prolonged neuromuscular blockade (lasting longer than 4 hours) after administration of a single dose of 0.08 mg/kg of vecuronium. Neuromuscular function was monitored by accelerometry with four-stimuli series. Many of the circumstances present in this case -such as prior administration of succinylcholine, the use of an inhaled anesthetic, kidney insufficiency and cyclosporin therapy- have been associated with increased duration of blockade induced by neuromuscular blockers, although durations reported have been shorter than that experienced by our patient. After electromyography and muscle biopsy, polyneuropathy and steroid-related myopathy were diagnosed. We conclude that neuromuscular blockers should be administered with extreme caution to patients with polyneuropathy and those undergoing long-term corticoid therapy, in order to prevent prolonged neuromuscular blockade.

[Epidural abscess secondary to the implantation of a thoracic catheter]

Spinal compression related to the formation of an epidural abscess after epidural blockade is a rare but serious complication. We report the case of a male patient in whom a thoracic epidural catheter was implanted to provide analgesia after trauma involving fracture ribs. The patient developed an epidural abscess within one week of implantation. Delay in diagnosis led to persistent neurogenic bladder symptoms in spite of aggressive treatment. We review causal factors, mechanisms of formation, pathogenesis, diagnosis and management, as well as possible relation between injury and abscess formation. We also emphasize the importance of adequate vigilance as well as rapid diagnosis and adoption of therapeutic measures in order to avoid permanent sequelae such as paresis, sensory deficits or mechanical sphincter dysfunction.