فصلنامه آنستزیولوژی و مراقبتهای ویژه ایران
سال بیست و نهم شماره 2 (پیاپی 58، تابستان 1386)

Heparin can induce a number of complications, including decreased number of platelets and inducing anti-platelet antibodies. This study was designed to compare these adverse effects between low molecular heparin and unfractionated heparin in patients diagnosed as deep vein thrombosis. In a clinical trial study, 124 cases diagnosed as deep vein thrombosis were divided randomly in 2 groups, 62 in each one. The first group was treated with enoxaparine and the 2nd treated with unfractionated heparin. Changes in platelet number and any new development of anti-platelet antibodies were assessed and compared between the groups. The cases in the 2 groups were compared regarding age, sex, and the platelet number. The decrease in platelet number was statistically significant in the unfractionated heparin while the 2nd group did not have any statistically significant decrease. The difference between the two groups was statistically significant regarding platelet count. The introduction of new anti-platelet antibody was significant in the unfractionated heparin group but not the enoxaparin group. None of the cases had a platelet number less than 100.000/ml. The study suggests that the enoxaparin is superior to unfractionated heparin regarding production of anti-platelet antibodies and decrease in platelet count. Serial platelet counts and the risk of thrombocytopenia should be considered when admininstering unfractionated heparin in deep vein thrombosis cases.

Postoperative nausea and vomiting (PONV) is frequent in patients undergoing general anesthesia. The incidence of PONV may be as high as 60-70%, and is influenced by various factors. P6, a Chinese meridian point is used for treatment of nausea and vomiting. To compare the efficacy of acupressure wrist bands and metoclopramide for the prevention of postoperative nausea and vomiting (PONV). One hundred fifty ASA I-II patients undergoing elective laparoscopic cholecystectomy were included in a randomized, prospective, double-blind and placebo-controlled study. Patients were divided into three groups of 50. Group I was the control; Group II received metoclopramide 0.2 mg/kg IV just prior to the end of anesthesia; in Group III acupressure wrist bands were applied at the P6 points. Acupressure wrist bands were placed inappropriately in Groups I and II. The acupressure wrist bands were applied 30 min prior to the induction of anesthesia and removed in the recovery room. Anesthesia was standardized. PONV, was evaluated separately as none, mild, moderate or severe within recovery room and two and six hrs after patient's arrival in the postanesthesia care unit and then 24 hrs after surgery by a blinded observer. If patients vomited more than once, they were given 0.2 mg/kg metoclopramide IV as the rescue antiemetIc. Results were analyzed by Z test. A p-value 0.05 was taken as significant. The incidence of PONV and the requirement of rescue medication were significantly lower in both the acupressure and metoclopramide groups during the first six hours. Acupressure at P6 causes a significant reduction in the incidence of PONV and the requirement for rescue medication in the first six hours following laparoscopic cholecystectomy, similar to that of metoclopramide given 0.2 mg/kg IV.

Pain is the most common side effects of ESWL for treatment of renal stones and opioids are well known agents for analgesia during this procedure. Remifentanil is a new opioid, and have a very short half life compare with other agents of this group, and its elimination is independent of kidney and liver function and is metabolized by unspecific tissue and blood esterases. The effect of this opioid on hemodynamic and quality of analgesia during ESWL is not well known. We compared the effect of two drugs of morphine sulfate and remifentanil on hemodynamic alteration and quality of analgesia during ESWL, using a randomized double blind clinical trial study on 70 ASA Class I or II, 15-45 years of age patients with renal stone candidated for ESWL. In group R (n=35) remifentanil was administered at bolus of 0.1 mg/kg during 30 seconds and infusion of 0.05 mg/kg/min until pain was tolerated and continuous infusion of 0.025 mg/kg/min. Morphine Was administered at 0.1 mg/kg bolus to group M (n=35) that received infusion of normal saline. We recorded mean blood pressure (MAP) and heart rate (HR) and arterial blood oxygen saturation (SpO2) of all patients before administering drug, before the prtocedure and each 5 minutes during the procedure, and intensity of pain was estimated by VRS (Verbal Rating Scale). Comparing D MAP, D HR, D SPO2 between two groups had no meaningful change. Mean of D VRS was meaningfully lower during ESWL in remifentanil group compare with morphine group (p< 0.05). In summary, remifentanil in dose of 0.025 mg/kg min provided a better analgesia compared with morphine sulfate and had adverse effect on hemodynamic of patients, so we concluded that: remifentanil can be an appropriate substitute for morphine sulfate.

Insertion of CVP catheters through internal jugular and subclavian veins has potentially dongerous complications like pneumothorax, arterial puncture, and nerve injury. Using peripherally inserted central catheters (PICC) devoids of these complications. To determine the optimum position of the tip of these catheters, intravenous ECG (IVECG) in used. In this study, we will try to find another technique just by measurement of skin surface distances. In 100 patients undergoing CABG, PICC were inserted using IVECG technique. The position of the catheter tip was determined by surgeon's palpation during operation. The data of the correctly positioned catheters were analysed by SPSS software and two formulae were obtained to measured distances of follow:Insertion length in right arm (cm) = [0.105 * height (cm)] + [0.661 * VJS (cm). Insertion length in left arm (cm) = [0.142 * height (cm)] + [0.599 * VJS (cm). VJS distance was measured between venipuncture site and sternal notch plus 1/3 of the sternal length. In another 40 patients PICC were inserted using the above formulae. The results of catheter insertion using two techniques of IVECG and skin surface measurements are depicted in the table. Position of the catheter tip within 2cm of the junction is an optimum place to measure CVP. There were no significant differences between the two techniques of IVECG and skin surface measurements (p=0.182). So using the above formulae is recommended when using IVECG has limitations or is impossible.

Both preoperative oral dextromethorphan (DM) and IV clonidine attenuates arterial blood pressure and heart rate increases during tourniquet inflation under general anesthesia. Effect of preoperative oral clonidine on these variables was not investig clinically, it seems that clonidine is more effective than DM in blunting of these responses. We designed this study to compare the effect of preoperative oral DM or clonidine on hemodynamic changes during tourniquet inflation in 75 patients undergoing lower limb surgery under general anesthesia. Patients were randomly assigned into three groups; DM (n = 25; DM 30 mg), clonidine (n = 25; clonidine 3 mg/kg), and control (n= 25; placebo) bgroups. Anesthesia was maintained with 1.2%-14% DM, clonidine, or placebo was given orally in a double-blinded fashion ninety minutes before induction of anesthesia. Systolic, diastolic, mean arterial blood pressure (SAP, DAP, MAP), and heart rate (HR) were measured at 0, 30, 45, 60 min after the start of tourniquet inflation, before tourniquet release (BTR), and 20 mins after tourniquet deflation. (20 ATR). SAP, DAP and MAP were significantly lower in the clonidine group compared with control after 45, 60 min tourniquet inflation and at BTR (p<0.05). Twenty minutes after deflation, DAP and MAP in the control group was still increased and significantly higher compared with the clonidine group. Development of more than a 30% increase in systolic arterial pressure during tourniquet inflation was more frequent in the control group than the other groups. Preoperative oral clonidine 3 mg/kg significantly prevented tourniquet-induced systemic arterial pressure in patients under general anesthesia better than oral DM.

Postoperative nausea and vomiting (PONV) is a very common side effect of intrathecal use of meperdine. Several drugs for preventing the PONV due to opioids are available currently; but none ofthem can be considered as gold standard. This study was designed to compare effects of haloperidol, metoclopramide and promethazine in preventing of PONV due to intrathecal use of meperidine. In a randomized clinical trial (RCT), effects of haloperidol, metoclopramide and promethazine in prventing PONV due to intrathecal use of meperidine were compared in 60 patients who had undergone orthopedic or urologic operations in Sina hospital from 2004 until 2006. In all patients spinal anesthesia protocol (100 mg lidocaine or 15 mg marcaine with 25 mg meperidine intrathecally) was the same. The patients were randomized to receive either haloperidol (2.5 mg IM, n=20) or metoclopramide (10 mg IM, n=20) or promethazine (25 mg IM, n=20). All the patients were evaluated for incidence of nausea and vomiting in definite intervals during first 24 hours after operation. The data were analyzed by SPSS with considering statistic level under 0.05. The prevalence of early nausea in haloperidol group (10%) was less in promethazine group (35%), and more in metoclopramide group (5%). Difference inearly nausea severity among study groups was statisitically significant (p=0.029). The prevalence of late nausea in study groups (5%) was the same, but severity of it was different. Only one patient in group had nausea in 12-24 hrs postoperation. The prevalence of early vomiting in haloperidol group (5%) was less in promethazine group (25%) (p=0.07) and the same in metoclopramide group (5%). The prevalence of late vomiting in haloperidol group (5%) was more in metoclopramide group (0) and the same in promethazine group (5%). None of patients in study groups had womiting in 12-24 hrs postoperation. For prevention of nausea and vomiting due to intrathecal meperidine in 0-4 hrs after initiation of surgery, metoclopramide and haloperidol are more effective than promethazine.

Induction of anesthesia and endotracheal intubation can have harmful effects on hemodynamic in hypertensive patients. In a single blind clinical trial study we compared alfentanil and remifentanil effects on hemodynamic parameters in hypertensive patients undergoing cataract surgery. 60 ASA class II patients were randomly allocated into two 30 patients group. One group received remifentanil 1 mg/kg bolus and 0.1 mg/kg/min infusion and the other group received 20 mg/kg of alfentanil bolus and 1 mg/kg/min infusion. Both groups underwent induction and endotracheal intubation with midazolam 0.1 mg/kg and cisatracurium 0.15mg/kg, MAP and PR were recorded before induction, after induction and intubation. The results were compared with t-test and p-value<0.05 was considered significant. 60 patients were allocated into two 30 patient groups. The average mean arterial pressure at the base time, after induction and after intubation 99.86, 87.76, 98.46 and in the remifentanil group and 98.16, 89.10 and 99.93 in the alfentanil group, respectively with no significant difference (p-value<0.05). The average heart rate at the base time, after induction, and after intubation was 61.10, 62.66 and 63.80 in the remifentanil group and 98.16, 89.10 and 98.46 in the alfentanil group. The difference between the two groups was not statistically signficant (p-value<0.05). We concluded that alfentanil and remifentanil in patients with controlled hypertension could not create significant changes in hemodynamic and sympathetic responses after induction of anesthesia and intubation.

The laryngeal mask airway (LMA) is a supraglotic airway device that can be used as a substitute for the standard endotracheal tube in emergency and difficult airway management. However, the use of LMA for elective surgical procedures is still controversial. In the most of published studies, ETCO2 and SpO2 monitoring were for assessment of adequacy of LMA placement. However, the most reliable method of evaluating ventilation and oxygenation is measurement of arterial oxygen partial pressure (PaO2) and arterial carbon dioxide partial pressure (PaCO2) directly from an arterial blood sample. The purpose of this descriptive cross-sectional study was to evaluate ventilation and oxygenation with ProSeal laryngeal mask airway (PLMA) during short-term elective gynecologic surgery in paralyzed anesthetized patients. 15 ASA class I-II women undergoing short-term elective gynecologic operations under general anesthsia were included to the study. After induction of standard general anesthesia an appropriate size of ProSeal LMA was inserted and controlled ventilation was established. Position of LMA was detected with ausculation of lungs and epigastric area. Before the end of surgery, arterial blood sample was withdrawn for blood gas analysis. First attempted insertion of PLMA was successful in all of the patients. The position of PLMA was good in 11, acceptable in 2 and suspected in 2 patients. PaO2, PaCO2 and SaO2 were in normal limits in all situations. Duration of anesthesia (>30 min and <30 min) had no effect on PaO2. We concluded that ventilation and oxygenation can be maintained through a PLMA during short-term gynecologic surgery under general anesthesia.