Didem Dal

The efficacy of intravenous or peritonsillar infiltration of ketamine for postoperative pain relief in children following adenotonsillectomy.

Background : A few previous studies have suggested the efficacy of i.v. ketamine for postoperative pain relief in children after adenotonsillectomy, but none has investigated the efficacy of peritonsillar infiltration of ketamine in these children.

Ketamine sedation during spinal anesthesia for arthroscopic knee surgery reduced the ischemia-reperfusion injury markers.

We studied the effect of ketamine sedation on oxidative stress during arthroscopic knee surgery with tourniquet application by determining blood and tissue malonyldialdehyde (MDA) and hypoxanthine (HPX) levels. Thirty ASA I–II patients undergoing arthroscopic knee surgery with tourniquet were randomly divided into two groups. Spinal anesthesia induced with 12.5 mg bupivacaine was administered to all patients. In the ketamine group, after IV administration of 0.01 mg/kg midazolam, a continuous infusion of ketamine (0.5 mg · kg−1 · h−1) was used until the end of surgery whereas the placebo group received a volume-equivalent placebo infusion. Ramsey Sedation Scale (RSS) was used for assessing the sedation level. Venous blood and synovial membrane tissue samples were obtained before ketamine infusion, at 30 min of tourniquet ischemia, and at 5 min after tourniquet deflation for MDA and HPX measurements. Tissue MDA and HPX levels were significantly less in the ketamine group than the control group after reperfusion. RSS scores were higher in the ketamine group without any adverse effect. We conclude that ketamine sedation attenuates lipid peroxidation markers in arthroscopic knee surgery with tourniquet application.

A background infusion of morphine does not enhance postoperative analgesia after cardiac surgery

PurposeTo compare the effects of patient-controlled analgesia (PCA), with or without a background infusion of morphine on postoperative pain relief and stress response after cardiac anesthesia.MethodsWith University Ethics approval, 35 consenting adults undergoing elective open-heart surgery were randomly assigned preoperatively in a double-blind fashion to receive either morphine PCA alone (Group I, n = 15) or morphine PCA plus a continuous basal infusion (Group II, n = 14) for 44 hr postoperatively. Pain scores with visual analogue scale (VAS) at rest, deep inspiration and with cough, sedation scores, stress hormone levels [cortisol, adrenocorticotropin (ACTH) and growth hormone (GH)] and morphine consumption were assessed, and serum morphine levels were measured at four, 20, 28 and 44 hr after surgery. Adverse effects including nausea, vomiting, constipation, urinary retention and pruritus were noted. Total blood, fluid requirements, drainage and urinary output were recorded.ResultsPostoperative morphine consumption at 44 hr was less in Group I (29.43 ±12.57 mg) than in Group II (50.14 ±16.44mg), P = 0.0006. There was no significant difference between groups in VAS scores, GH levels, blood levels of morphine and adverse effects. While VAS scores, ACTH and GH levels decreased significantly in both groups, plasma cortisol levels increased significantly in Group I only at four hours. In Group II, ACTH and cortisol were higher at four and 44 hr respectively.ConclusionPCA with morphine effectively controlled postoperative pain after cardiac surgery. The addition of a background infusion of morphine did not enhance analgesia and increased morphine consumption.RésuméObjectifComparer les effets de l’analgésie autocontrôlée (AAC), avec ou sans une perfusion de morphine de base, sur l’analgésie postopératoire et la réaction de stress à la suite d’une anesthésle cardiaque.MéthodeNotre étude a été menée en double aveugle, avec l’accord du comité d’éthique de l’université, auprès de 35 adultes consentants devant subir une opération à cœur ouvert réglée. Les patients ont reçu, soit de la morphine en AAC seule (Groupe I, n = 15), soit de la morphine en AAC plus une perfusion de base continue (Groupe II, n = 14) pendant 44 h après l’opération. Nous avons évalué: la douleur, au repos, pendant l’inspiration profonde et la toux, selon une échelle visuelle analogique (EVA), la sédation, les niveaux d’hormones de stress [cortisol, les hormones adrénocortlcotropes (ACTH) et de croissance (GH)] et la consommation de morphine, ainsi que les niveaux sériques de morphine à quatre, 20, 28 et 44 h après l’opération. Les effets indésirables, incluant les nausées, les vomissements, la constipation, la rétention urinalre et le prurit ont été notés. Le sang total, les besoins liquidiens, le débit de drainage et la diurèse ont été enregistrés.RésultatsÀ 44 h, la consommation de morphine postopératoire était plus faible dans le Groupe I (29,43 ±12,57 mg) que dans le Groupe II (50,14 ±16,44 mg), P = 0,0006. Il n’y avait pas de différence Intergroupe significative des scores à I’EVA, des niveaux de GH, des niveaux sanguins de morphine et d’effets Indésirables. Les scores à I’EVA, les niveaux d’ACTH et de GH ont diminué slgnificativement dans les deux groupes, mais le cortisol plasmatique a augmenté de façon significative dans le Groupe I, à quatre heures seulement. Dans le Groupe II, l’ACTH et le cortisol étalent respectivement plus élevés à quatre et 44 h.ConclusionL’AAC avec de la morphine réduit efficacement la douleur postopératoire en cardiochirurgie, L’ajout d’une perfusion de base de morphine n’améliore pas l’analgésie, mais augmente la consommatlon de morphine.

Effect of low-dose N-acetyl-cysteine infusion on tourniquet-induced ischaemia-reperfusion injury in arthroscopic knee surgery.

Background:  Temporary occlusion of blood flow is used during arthroscopic knee surgery in order to provide a bloodless surgical field. The resulting ischaemia‐reperfusion causes lipid peroxidation, which contributes to tissue injury. The aim of the study was to investigate the effect of low‐dose n‐acetyl cysteine (NAC) infusion on oxidative stress by determining malondialdehyde (MDA) levels during arthroscopic knee surgery.

The efficacy of ketamine for the treatment of postoperative shivering.

BACKGROUND:There are few reports on the utility of ketamine for the prevention of postoperative shivering. We thus established the efficacy of two doses of ketamine compared with meperidine for the treatment of postoperative shivering. METHODS:This is a prospective, randomized double-blind study involving 90 ASA I–II patients after general anesthesia. Patients with shivering grade 3–4 were allocated to receive either meperidine 25 mg, ketamine 0.5 mg/kg, or ketamine 0.75 mg/kg IV. Shivering and side effects were monitored at set time intervals. RESULTS:Shivering grades for the first 4 min after treatment were lower in the ketamine groups; however, nystagmus and feeling like “walking in space” was experienced with both doses of ketamine. CONCLUSION:Ketamine 0.5–0.75 mg/kg is more rapid than meperidine (25 mg) for the reduction of postoperative shivering, but the side effect profile may limit its usefulness.

Induced hypotension for tympanoplasty: a comparison of desflurane, isoflurane and sevoflurane

Background and objectives: This prospective, randomized, double-blinded study was designed to compare the effects of desflurane, isoflurane and sevoflurane when combined with remifentanil for induced hypotension on surgical conditions and operative field during tympanoplasty. Methods: Sixty patients undergoing tympanoplasty were enrolled in the study. The patients were randomized into three groups of 20 each to receive the inhalation anaesthetics desflurane, isoflurane or sevoflurane. Propofol 2 mg kg−1 was administered for induction of anaesthesia in all groups. All patients received a continuous infusion of remifentanil which was titrated between 0.2 and 0.5 μg kg−1 min−1 to achieve a mean blood pressure (BP) of 60-70 mmHg. Nitroglycerine was infused if this BP could not be achieved. Arterial pressures were recorded continuously throughout the operation. Surgical conditions were assessed every 20 min by the blinded surgeon using a six-point category scale (0-5). Results: One patient in the desflurane group and two patients in isoflurane group required nitroglycerine to maintain desired mean BP. Sustained controlled hypotension was sufficient in all of the groups throughout surgery. Category scale scores were ⩽3 throughout the study, except one patient in the sevoflurane group who had a score of 4 at the 60th minute of the operation. No difference was found among groups when haemodynamic parameters and surgical category scale scores were compared. There were no postoperative respiratory and circulatory complications. Conclusion: Desflurane, sevoflurane or isoflurane combined with remifentanil provided adequate induced hypotension and similar operating conditions and any of them could be safely and equally used in anaesthesia for tympanoplasty.

Perioperative anxiety and postoperative behavioural disturbances in children : comparison between induction techniques

Background and objective: This study was designed to determine if subhypnotic propofol reduces postoperative behavioural disturbances in children undergoing sevoflurane induction compared with intravenous propofol induction for elective adenoidectomy and tonsillectomy. Methods: Following Ethics Committee approval and parental informed consent, ASA I–II, 120 children (2–10 yr) were recruited. Parents were not allowed to accompany their child. Unpremedicated children were randomly allocated to groups receiving inhalation induction with sevoflurane, 2–2.5 mg kg−1 intravenous propofol induction or inhalation induction with sevoflurane followed by subhypnotic dose of propofol (1 mg kg−1). Anaesthesia was maintained with 2–4% sevoflurane, O2 and N2O. Anxiety on arrival to operating theatre, at anaesthesia induction and 30 min after emergence was assessed. Parents completed a state–trait anxiety inventory test preoperatively and a post hospitalization behaviour questionnaire a week later to assess childrens postoperative behavioural disturbances. Kruskal–Wallis test, Wilcoxon signed rank sum test, Bonferronis test, Paired t‐test, t‐test, Pearson and Spearmans rank correlation test, χ2‐test were used for statistical analysis. Results: The anxiety level at induction was high in all groups (P < 0.05). There was no difference between groups in respect to anxiety at other measurement times. A relation between preoperative anxiety level and postoperative behavioural disturbances was determined (P < 0.05). Some behavioural disturbances as nightmare/night fear and desire of sleeping with parents were rarely seen in intravenous propofol induction group (P < 0.05). Conclusion: Addition of subhypnotic dose of propofol to sevoflurane induction did not reduce the incidence of postoperative behavioural disturbances.

The effect of ketamine on acute muscular ischaemia reperfusion in rats.

Background and objective: The aim of this study was to investigate any possible protective effect of ketamine in acute muscular ischaemia and reperfusion injury by measuring malondialdehyde using thiobarbituric acid assay in rats. Methods: Twelve female Wistar albino rats were anaesthetized with chloral hydrate and randomly assigned into two groups to receive ketamine 1 mg kg−1 min−1 or saline infusion. Blood and gastrocnemius muscle samples were obtained 10 min after onset of infusion, before ischaemia. Then, femoral arteries were clamped for 30 min. Blood and muscle samples were obtained at the 30th minute of ischaemia and 10 min after reperfusion. Results: Muscle malondialdehyde concentrations were 27.88 ± 2.45, 27.62 ± 3.98 before ischaemia, 32.10 ± 4.19, 30.77 ± 2.73 in the 30th minute of ischaemia and 44.34 ± 2.45, 34.83 ± 2.78 after reperfusion in saline and ketamine‐treated rats, respectively (nmol g−1, mean ± SD). The muscle malondialdehyde level after reperfusion was lower in ketamine‐treated rats compared to saline group (P < 0.002). Plasma malondialdehyde levels were 3.77 ± 0.16, 3.78 ± 0.18 before ischaemia, 3.81 ± 0.25, 4.00 ± 0.86 at the 30th minute of ischaemia and 4.00 ± 0.53, 3.94 ± 0.95 after reperfusion, respectively, in saline and ketamine‐treated rats (μmol L−1, mean ± SD). The effect of ketamine on muscular malondialdehyde was not observed in concurrent plasma malondialdehyde levels. Conclusion: Ketamine was found to attenuate acute ischaemia‐reperfusion injury in muscle tissue in rats (muscular protective). Ketamine may attenuate lipid peroxidation in muscle tissue in tourniquet‐requiring manoeuvres.

Anesthetic management of a strabismus patient with phenylketonuria.

intubation or a nasopharyngeal airway for inhalation anesthesia during the intubation procedure. Pulling out the tongue with Magill forceps (6) and jaw thrust obviously made it easier to pass the fiberscope behind the base of the tongue. The gentle cricoid pressure made it possible to reach the laryngeal inlet with the tip of the scope. The key points in managing the difficult airway in our patient were to maintain spontaneous respiration and to have experience in orotracheal fiberoptic intubation. Eva Nilsson M D D E A A* Leif Ingvarsson M D P h D† Erik Isern M D‡ *Department of Anaesthesiology, †Department of ENT-surgery, University Hospital of Malmö, Sweden and ‡Department of Anaesthesiology, University Hospital of Trondheim, Norway

Cardiac arrest in a patient with Larsen syndrome under sevoflurane anesthesia

SIR—We read with interest the report of Morishima et al. who reported three consecutive general anesthetics using sevoflurane in the same patient with Larsen syndrome (1). We would like to report a child with Larsen syndrome who had a cardiac arrest and died during spinal surgery under sevoflurane anesthesia. A 6 year old, 20 kg boy with Larsen syndrome was scheduled for spinal surgery to treat progressive kyphoscoliosis. The patient was examined by the Department of Pediatric Cardiology and they reported, LVEDD: 43 mmHg, LVESD: 31.5, EF: 53%, TR:I-III (RVSP: 50–55 mmHg) MR: I, MVP, AVP, TVP by echocardiography. Anesthesia was induced and maintained with nitrous oxide, oxygen, and sevoflurane at concentrations of 8 and 1.5%, respectively. We did not have trouble with intubation. The larynx was easily seen and intubated with a 5.5 mm reinforced tracheal tube. We administered fentanyl 40 lg (2 lgÆkg) for analgesia at the beginning of the surgery. After induction, a second 16G intravenous canula, a femoral central catheter and arterial line were placed. The patient was then turned prone on a Gardner frame with padded supports for the pelvic and thoracic area. We used controlled ventilation during the operation. Before the skin incision and throughout the procedure, the mean arterial pressure (MAP) was maintained at 60–70 mmHg. Four hours into the procedure, as the blood loss was 320 ml and we had given 200 ml packed-red cells, there was an abrupt fall in the systolic blood pressure from 90 to 48 mmHg. At the same time, the electrocardiogram changed, with T-wave inversion and abrupt fall in heart rate, from 110 to 40 bÆmin. Within 30 s of initial decrease in blood pressure, the patient became asystolic and had no palpable pulse. There was no response to an initial dose of epinephrine (0.5 mg) and atropine (0.5 mg). The patient was turned supine and cardiopulmonary resuscitation was started. We gave three additional doses of epinephrine and sodium bicarbonate (50 mmol each). CPR was maintained for 2 h but no cardiac rhythm returned so attempts were abandoned. The blood loss was not so large as to cause to hypovolemia. We believe that the sudden hypotension and bradycardia was caused by a cardiac complication of Larsen syndrome. We think that patients with Larsen syndrome associated with cardiac problems may not tolerate procedures such as spinal surgery in the prone position even with sevoflorane which has less myocardial depression than other inhalational anesthetic agents. Fatma Sar ıcaoğlu , M D Didem Dal , M D Faculty of Medicine, Department of Anesthesiology and Reanimation, Hacettepe University School of Medicine, Ankara, Turkey (email: fatmasaricao@yahoo.com)