Stefano Veronese

Hemodynamic and Hormonal Stress Responses to Endotracheal Tube and ProSeal Laryngeal Mask Airway ™ for Laparoscopic Gastric Banding.

Background: The stress responses from tracheal intubation are potentially dangerous in patients with higher cardiovascular risk, such as obese patients. The primary outcome objective of this study was to test whether, in comparison with the endotracheal tube (ETT), the Proseal™ Laryngeal Mask Airway (PLMA™) (Laryngeal Mask Airway Company, Jersey, United Kingdom) reduces blood pressure and norepinephrine responses and the amounts of muscle relaxants needed in obese patients. Methods: We assessed hemodynamic and hormonal stress responses, ventilation, and postoperative recovery in 75 morbidly obese patients randomized to receive standardized anesthesia with either an ETT or the PLMA™ for laparoscopic gastric banding. Results: In repeated-measures ANOVA, mean arterial blood pressure and plasma norepinephrine were significantly higher in the ETT group than in the PLMA™ group. In individual pairwise comparisons, blood pressure rose higher in ETT than PLMA™ patients after insertion and removal of airway devices, and after recovery. In ETT compared with PLMA™ patients, plasma norepinephrine was higher after induction of carboperitoneum (mean ± SD, 534 ± 198 and 368 ± 147 and pg/ml, P = 0.001), after airway device removal (578 ± 285 and 329 ± 128 pg/ml, P < 0.0001), and after recovery in postanesthesia care unit (380 ± 167 and 262 ± 95 and pg/ml, P = 0.003). Compared with use of the ETT, the PLMA™ reduced cisatracurium requirement, oxygen desaturation, and time to discharge from both the postanesthesia care unit and the hospital. Conclusions: PLMA™ reduces stress responses and postoperative complaints after laparoscopic gastric banding.

Tetraplegia following thyroidectomy in a patient with spinal meningioma

Editor—A 42-yr-old, 80 kg male was undergoing elective total thyroidectomy. The patient had a history of arterial hypertension and Wolf–Parkinson–White syndrome, but had no neurological symptoms. Neck and neurological evaluations were normal. Anaesthesia was induced with propofol 2.5 mg kg and fentanyl 1 mg kg. After administration of rocuronium 0.6 mg kg, tracheal intubation was technically easy and did not require neck extension. Ventilation was set to a 30/70 oxygen/air mixture, volume control ventilation with inspiratory tidal volume of 10 ml kg, respiratory rate of 10 bpm, and inspiratory:expiratory ratio of 1:2. Anaesthesia was maintained with fentanyl 3 mg kg and desflurane at about 0.7 MAC as required to keep the arterial pressure and heart rate within 20% of baseline values. The patient was positioned supine with a pillow under his shoulders to facilitate neck extension. The uneventful surgical procedure lasted 90 min. Before wound closure, positive end-expiratory pressure 10 cm H2O for 20 s was applied to assess haemostasis. On awakening, the patient was able to obey commands by moving his eyes, but not to squeeze with his hand or move his limbs. Neurological assessment revealed flaccid areflexic tetraplegia and anaesthesia below C4 level, with intact cranial nerve function. The patient was assessed as Grade A Frankel classification. A magnetic resonance (MR) scan was performed urgently. Sagittal views of the cervicothoracic spine revealed spinal cord compression at C2–C5 level due to a ventrally located spinal meningioma and oedema of spinal cord (Fig. 1). The patient underwent immediate C2–C5 decompressive laminectomy. He was transferred to the intensive care unit. Tetraplegia remained unchanged throughout the postoperative course. Tracheostomy was performed on the fifth postoperative day. He was able to breathe spontaneously from the 14th postoperative day. He was transferred to neurological rehabilitation unit on the 18th postoperative day. Tetraplegia on awakening from anaesthesia after thyroidectomy represents an exceptional event. The most likely causes are spinal cord ischaemia, epidural haematoma, and spinal cord injury from direct compression or retraction. A posterior protrusion of the disc annulus or age-related pathologic processes, including osteophyte formation and ossification of the posterior longitudinal ligament, may lead to the compression of the spinal cord after an extension of the neck. Meningiomas are benign tumors arising from arachnoid cells and are mostly located in the intracranial compartment. Spinal meningiomas are rare and account for about 1.2% of all meningiomas and 25% of all spinal cord tumors. In our case, the spinal meningioma and the neck hyperextension that is usually required by this surgical procedure are the main factors involved in the genesis of the spinal cord injury. – 6 Neck hyperextension decreases the spinal canal length and increases its area, whereas the spinal cord is shortened. The shortening and folding of the spinal cord when the cervical spine is in extension may result in a relative increase in the ratio of spinal cord size to spinal canal lumen, despite the potential increase in the lumen. The meningioma, in this case, further reduced the space available for the spinal cord and determined a direct compression and the impairment of the perfusion of the spinal cord during the hyperextension period. The manipulation of the neck, 8 the increase in cerebrospinal fluid, and the venous pressures values 8 during the surgical procedure may have contributed to the injury. Neither systemic hypotension nor hypoxaemia occurred during anaesthesia. The pathophysiology of acute spinal cord injury is biphasic, consisting of a primary and secondary phase of injury. Compressive neural damage may have been the primary mechanical injury and this occurred rapidly. 9 10 The subsequent secondary injury phase would involve vascular dysfunction, oedema, ischaemia, excitotoxicity, electrolyte shifts, free radical production, and inflammation with release of proinflammatory cytokines (i.e. TNF-a and IL-b). The secondary injury phase began at the time of injury and was maintained by spinal cord compression.

Atropine sulfate for treatment of bradycardia in a patient with morbid obesity: what may happen when you least expect it

A 74-year-old morbidly obese man was scheduled for surgical repair of an incisional ventral hernia. Anaesthesia was induced with propofol and fentanyl, and maintained with desflurane. A second dose of fentanyl 0.2 mg, given before starting surgery, resulted in sinus bradycardia and mild decrease of arterial blood pressure. Atropine sulfate 0.5 mg was administered. One minute later, the ECG rhythm on the monitor changed to third degree atrioventricular block with a ventricular response rate of 40 beats/min associated with marked hypotension. Isoproterenol 0.02 mg reverted the atrioventricular block to sinus rhythm. Cardiac enzymes and ECG ruled out acute myocardial ischaemia. The surgical procedure and the recovery from anaesthesia were uneventful. The patient was discharged from the hospital on the fifth postoperative day. For the treatment of bradycardia atropine sulfate should be adjusted at least to lean body weight in order to avoid paradoxical heart rate response in patients with obesity.

Recovery profiles of general anesthesia and spinal anesthesia for chemotherapeutic perfusion with circulatory block (stop-flow perfusion)

BACKGROUND:Chemotherapeutic stop-flow perfusion is a new investigational treatment for locally advanced cancers that is usually performed under general anesthesia (GA), and, less frequently, under spinal anesthesia (SA). We designed this clinical trial to compare the clinical profiles of GA and SA for stop-flow perfusion. METHODS:Anesthesia and recovery times, scores on visual analog scales for postoperative pain, and postoperative nausea and vomiting, and admission to the postanesthesia care unit were measured in 40 cancer patients who randomly received either GA with propofol, nitrous oxide/sevoflurane, and fentanyl, or SA with bupivacaine hydrochloride for lower limb or pelvic stop-flow perfusion. RESULTS:GA and SA did not differ in times to achieve home readiness or patient satisfaction. Compared with GA, SA significantly (P < 0.05) reduced anesthesia times (34 vs 16 min), postoperative visual analog scale scores for pain (5 vs 0) and nausea (8 vs 2), and the number of admissions to the postanesthesia care unit (9 vs 0). CONCLUSIONS:For stop-flow perfusion, GA and SA are both effective, but SA provides faster recovery, superior analgesia, and less postoperative nausea and vomiting in the immediate postoperative period.

Low-dose ketamine with clonidine and midazolam for adult day care surgery.

EDITOR: The ideal anaesthetic for day-surgery procedures should give quick recovery without pain, nausea or vomiting and ensure a rapid return to preoperative mental state with rapid discharge and patient satisfaction. Ketamine was introduced into clinical practice nearly 40 yr ago but its use has declined. It nevertheless remains in regular use in certain surgical disciplines, e.g. paediatrics, plastic and burn surgery, during emergencies or during short diagnostic procedures. However, when administered to adult patients as the sole anaesthetic it frequently causes emergence reactions characterized by anxiety and hallucinations. A number of agents, including midazolam and clonidine, have been used to reduce or prevent these reactions. The aim of the present study was to test whether the combination of low-dose ketamine with midazolam, clonidine and ketorolac but without opioid administration, could provide adequate anaesthesia for interventions with low-to-medium pain potential performed on a day-surgery basis. This included breast surgery, laparoscopy, superficial excision of minor lesions, thoracoscopy, appendicectomy and proctological surgery. Five hundred patients, (172 males and 328 females) ASA Grade I–II, were enrolled in the study. All gave written, informed consent and were instructed in the use of the visual analogue scale (VAS). Overall mean age was 53.9 (SD 12.2) yr and mean weight 76.1 (SD 22.5) kg. Sedation was assessed using the Observer’s Assessment of Alertness/Sedation Scale (OAA/S) [1] and cognitive function was assessed with the Mini Mental State Examination [2]. The Profile of Mood State was used to assess mood [3]. Heart rate (HR), respiratory rate, oxygen saturation and arterial pressure were measured before and during surgery and for 1 h afterwards. Before induction of anaesthesia with propofol 2 mg kg 1, patients were given atropine 0.01 mg kg 1, midazolam 0.03– 0.05 mg kg 1 and ketamine 0.4 mg kg 1 all intravenously (i.v.). All patients received nitrous oxide 65% in oxygen. Muscle relaxation was obtained with suxamethonium (1.0–1.5 mg kg 1) or vecuronium (0.1 mg kg 1) for tracheal intubation and maintained with vecuronium. After tracheal intubation patients were given clonidine 150 μg i.v. If depth of anaesthesia was not adequate (blood pressure, BP or HR 20% of the preinduction values, lacrimation and sweating) patients were given ketamine 0.4– 0.6 mg kg 1 (maximum total dose 1 mg kg 1) or bolus injections of propofol 0.5 mg kg 1. The last ketamine administration was at least 1 h before the end of surgery. Ketorolac 30 mg and dexamethasone 8 mg were administered i.v. 30 min before wound closure. Total dose of ketamine used was 0.6 (SD 0.2) mg kg 1. At the end of the procedure, neuromuscular block was reversed using neostigmine, nitrous oxide was discontinued and the interval from this time to eye opening was recorded. Overall mean duration of surgery and anaesthesia were 121.4 (SD 60.1) min and 146.4 (SD 63.5) min, respectively. Time from discontinuation of nitrous oxide to eye opening was 176.9 (SD 106.1) s. Immediately after extubation and every 10 min thereafter, VAS scores for pain, sleepiness and nausea, OAA/S, and Aldrete score [4] were measured. In the first postoperative hour, ketorolac 0.3–0.6 mg kg 1 was administered if VAS for pain was 30. Patients were discharged from the recovery room when two consecutive Aldrete scores were 9 and all VAS scores were 30. At this time, the Profile of Mood State and Mini Mental State examination were repeated and patients were asked whether they felt strange or disoriented. Vital signs, nausea, pain, sleepiness and readiness for discharge from the hospital were assessed at 2, 3 and 4 h from the end of surgery. Patients were judged ‘ready for discharge’ (even if not actually dismissed from the hospital) when they had stable vital signs: no nausea, were oriented, able to ambulate unassisted Correspondence to: Carlo Ori, Dipartimento di Farmacologia ed Anestesiologia, Sezione di Anestesiologia e Rianimazione, Università degli Studi di Padova, via C. Battisti, 267 35121 Padova, Italy. E-mail: carloori@unipd.it; Tel: 39 0498213090; Fax: 39 0498754256