Jean Joris

Hemodynamic changes during laparoscopic cholecystectomy.

Hemodynamics during laparoscopic cholecystectomy under general anesthesia (isoflurane in N2O/O2 (50%)) were investigated in 15 nonobese ASA Class I patients by using invasive hemodynamic monitoring including a flow-directed pulmonary artery catheter. During surgery, intraabdominal pressure was maintained automatically at 14 mm Hg by a CO2 insufflator, and minute ventilation was controlled and adjusted to avoid hypercapnia. Hemodynamics were measured before anesthesia, after the induction of anesthesia, after tilting into 10° head-up position, 5 min, 15 min, and 30 min after peritoneal insufflation, and 30 min after exsufflation. Induction of anesthesia decreased significantly mean arterial pressure and cardiac index (CI). Tilting the patient to the head-up position reduced cardiac pre-load and caused further reduction of CI. Peritoneal insufflation resulted in a significant increase (±35%) of mean arterial pressure, a significant reduction (±20%) of CI, and a significant increase of systemic (±65%) and pulmonary (±90%) vascular resistances. The combined effect of anesthesia, head-up tilt, and peritoneal insufflation produced a 50% decrease in CI. Administration of increasing concentrations of isoflurane, via its vasodilatory activity, may have partially blunted these hemodynamic changes. These results demonstrate that laparoscopy for cholecystectomy in head-up position results in significant hemodynamic changes in healthy patients, particularly at the induction of pneumoperitoneum.

Intravenous lidocaine infusion facilitates acute rehabilitation after laparoscopic colectomy

Background:Intravenous infusion of lidocaine decreases postoperative pain and speeds the return of bowel function. The authors therefore tested the hypothesis that perioperative lidocaine infusion facilitates acute rehabilitation protocol in patients undergoing laparoscopic colectomy. Methods:Forty patients scheduled to undergo laparoscopic colectomy were randomly allocated to receive intravenous lidocaine (bolus injection of 1.5 mg/kg lidocaine at induction of anesthesia, then a continuous infusion of 2 mg · kg−1 · h−1 intraoperatively and 1.33 mg · kg−1 · h−1 for 24 h postoperatively) or an equal volume of saline. All patients received similar intensive postoperative rehabilitation. Postoperative pain scores, opioid consumption, and fatigue scores were measured. Times to first flatus, defecation, and hospital discharge were recorded. Postoperative endocrine (cortisol and catecholamines) and metabolic (leukocytes, C-reactive protein, and glucose) responses were measured for 48 h. Data (presented as median [25–75% interquartile range], lidocaine vs. saline groups) were analyzed using Mann–Whitney tests. P < 0.05 was considered statistically significant. Results:Patient demographics were similar in the two groups. Times to first flatus (17 [11–24] vs. 28 [25–33] h; P < 0.001), defecation (28 [24–37] vs. 51 [41–70] h; P = 0.001), and hospital discharge (2 [2–3] vs. 3 [3–4] days; P = 0.001) were significantly shorter in patients who received lidocaine. Lidocaine significantly reduced opioid consumption (8 [5–18] vs. 22 [14–36] mg; P = 0.005) and postoperative pain and fatigue scores. In contrast, endocrine and metabolic responses were similar in the two groups. Conclusions:Intravenous lidocaine improves postoperative analgesia, fatigue, and bowel function after laparoscopic colectomy. These benefits are associated with a significant reduction in hospital stay.

Pain after laparoscopic cholecystectomy : characteristics and effect of intraperitoneal bupivacaine

Although pain after laparoscopic cholecystectomy is less intense than after open cholecystectomy, some patients still experience considerable discomfort.Furthermore, the characteristics of post-laparoscopy pain differ considerably from those seen after laparotomy. Therefore, we investigated the time course of different pain components after laparoscopic cholecystectomy and the effects of intraperitoneal bupivacaine on these different components. Forty ASA physical status grade I-II patients were randomly assigned to receive either 80 mL of bupivacaine 0.125% with epinephrine 1/200,000 (n = 20) or the same volume of saline (n = 20) instilled under the right hemidiaphragm at the end of surgery. Intensity of total pain, visceral pain, parietal pain, and shoulder pain was assessed 1, 2, 4, 6, 8, 24, and 48 h after surgery. Analgesic consumption was also recorded. Patient data were similar in the two groups. In the saline group, visceral pain was significantly more intense than parietal pain at each time point; visceral and parietal pain were greater than shoulder pain during the first 8 h postoperatively. Intraperitoneal bupivacaine did not significantly affect any of the different components of postoperative pain. Analgesic consumption was similar in the two groups. This study demonstrates that visceral pain accounts for most of the pain experienced after laparoscopic cholecystectomy. Intraperitoneal bupivacaine is not effective for treating any type of pain after laparoscopic cholecystectomy. (Anesth Analg 1995;81:379-84)

Psychological approaches during conscious sedation. Hypnosis versus stress reducing strategies: a prospective randomized study

&NA; Stress reducing strategies are useful in patients undergoing surgery. Hypnosis is also known to alleviate acute and chronic pain. We therefore compared the effectiveness of these two psychological approaches for reducing perioperative discomfort during conscious sedation for plastic surgery. Sixty patients scheduled for elective plastic surgery under local anesthesia and intravenous sedation (midazolam and alfentanil upon request) were included in the study after providing informed consent. They were randomly allocated to either stress reducing strategies (control: CONT) or hypnosis (HYP) during the entire surgical procedure. Both techniques were performed by the same anesthesiologist (MEF). Patient behavior was noted during surgery by a psychologist, the patient noted anxiety, pain, perceived control before, during and after surgery, and postoperative nausea and vomiting (PONV). Patient satisfaction and surgical conditions were also recorded. Peri‐ and postoperative anxiety and pain were significantly lower in the HYP group. This reduction in anxiety and pain were achieved despite a significant reduction in intraoperative requirements for midazolam and alfentanil in the HYP group (alfentanil: 8.7±0.9 &mgr;g kg−1/h−1 vs. 19.4±2 &mgr;g kg−1/h−1, P<0.001; midazolam: 0.04±0.003 mg kg−1/h−1 vs. 0.09±0.01 mg kg−1/h−1, P<0.001). Patients in the HYP group reported an impression of more intraoperative control than those in the CONT group (P<0.01). PONV were significantly reduced in the HYP group (6.5% vs. 30.8%, P<0.001). Surgical conditions were better in the HYP group. Less signs of patient discomfort and pain were observed by the psychologist in the HYP group (P<0.001). Vital signs were significantly more stable in the HYP group. Patient satisfaction score was significantly higher in the HYP group (P<0.004). This study suggests that hypnosis provides better perioperative pain and anxiety relief, allows for significant reductions in alfentanil and midazolam requirements, and improves patient satisfaction and surgical conditions as compared with conventional stress reducing strategies support in patients receiving conscious sedation for plastic surgery.

Hemodynamic changes induced by laparoscopy and their endocrine correlates: effects of clonidine

OBJECTIVES We investigated endocrine correlates of the hemodynamic changes induced by carbon dioxide pneumoperitoneum (PNO). We then studied whether clonidine might modulate the hemodynamic changes induced by PNO by reducing release of catecholamines and vasopressin. BACKGROUND Both mechanical and neurohumoral factors contribute to the hemodynamic changes induced by carbon dioxide PNO. Several mediators have been proposed, but no study has correlated hemodynamic changes with changes in levels of these potential mediators. METHODS We conducted two studies, each including 20 healthy patients scheduled for elective laparoscopic cholecystectomy. In the first study serial measurements of hemodynamics (thermodilution technique) were done during laparoscopy and after exsufflation. Plasma concentrations of cortisol, catecholamines, vasopressin, renin, endothelin and prostaglandins were measured at the same time points. In the second study patients were randomly allocated to receive 8 microg/kg clonidine infused over 1 h or placebo before PNO. Hemodynamics and plasma levels of cortisol, catecholamines and vasopressin were measured during PNO and after exsufflation. RESULTS Peritoneal insufflation resulted in a significant reduction of cardiac output (18+/-4%) and increases in mean arterial pressure (39+/-8%) and systemic (70+/-12%) and pulmonary (98+/-18%) vascular resistances. Laparoscopy resulted in progressive and significant increases in plasma concentrations of cortisol, epinephrine, norepinephrine and renin. Vasopressin plasma concentrations markedly increased immediately after the beginning of PNO (before PNO 6+/-4 pg/ml; during PNO 129+/-42 pg/ml; p < 0.05). The profile of vasopressin release paralleled the time course of changes in systemic vascular resistance. Prostaglandins and endothelin did not change significantly. Clonidine significantly reduced mean arterial pressure, heart rate and the increase in systemic vascular resistance. Clonidine also significantly reduced catecholamine concentrations but did not alter vasopressin and cortisol plasma concentrations. CONCLUSIONS Vasopressin and catecholamines probably mediate the increase in systemic vascular resistance observed during PNO. Clonidine before PNO reduces catecholamine release and attenuates hemodynamic changes during laparoscopy.

Hemodynamic changes and catecholamine release during laparoscopic adrenalectomy for pheochromocytoma

UNLABELLED We investigated hemodynamics and plasma catecholamine concentrations in eight consecutive patients undergoing laparoscopic adrenalectomy for suspected pheochromocytoma. The same anesthesia protocol was used in all patients: a continuous infusion of sufentanil 0.5 microg x kg(-1) x h(-1) and isoflurane 0.4% (end-tidal) in 50% N2O/O2. Systolic arterial pressure was maintained between 120 and 160 mm Hg by adjusting an infusion of nicardipine, a calcium-channel blocker, while tachycardia (>100 bpm) was treated by 1-mg boluses of atenolol. Hemodynamics (thermodilution technique) and plasma catecholamine concentrations were measured before surgery, after the induction of anesthesia, after turning the patient to the lateral position, during pneumoperitoneum, during tumor manipulation, after adrenalectomy, and at the end of surgery. Two events resulted in significant catecholamine release: creation of the pneumoperitoneum and adrenal gland manipulation. As a consequence, a twofold increase in cardiac output was recorded. Adjustments of nicardipine infusion (2-6 microg x kg(-1) x min(-1)) minimized changes in mean arterial pressure. Beta-adrenergic blockade was necessary in six patients. In conclusion, laparoscopic adrenalectomy for pheochromocytoma results in marked catecholamine release during pneumoperitoneum and tumor manipulation. Titration of a nicardipine infusion allowed easy and quick control of the hemodynamic aberrancies related to these processes. IMPLICATIONS Pneumoperitoneum during laparoscopy, now used for adrenalectomy, may complicate anesthetic management of patients with pheochromocytoma. In this study, laparoscopic adrenalectomy was associated with catecholamine release during the creation of pneumoperitoneum and tumor manipulation. Adjustments of a nicardipine infusion readily attenuated the subsequent hemodynamic aberrancies.

Clonidine and ketanserin both are effective treatment for postanesthetic shivering

Background:Although meperidine is an effective treatment of postanesthetic shivering, its mechanism of action remains unknown. Investigation of other drugs might help clarify the mechanisms by which shivering can be controlled. Accordingly, we investigated the efficacy of clonidine, an α2-adrenergic agonist, and ketanserin, a 5-hydroxytryptamine antagonist, in treating postanesthetic shivering. Methods:First, 54 patients shivering after general anesthesia were allocated randomly to receive an intravenous bolus of saline, 150 µg clonidine, or 10 mg ketanserin. A second study explored the dose-dependence of clonidine. Forty shivering patients were given saline or clonidine, 37.5, 75, or 150 µg. Results: The duration of shivering was significantly shorter in those given clonidine (2.1 ± 0.9 min) than in the other two groups and shorter in the ketanserin group (4.3 ± 0.9 min) than in the saline group (12.0 ± 1.6 min). Clonidine and ketanserin significantly decreased systolic arterial blood pressure when compared to saline. Core rewarming was significantly slower in the clonidine group. In the second study, 37.5 µg clonidine was no more effective than saline. Two minutes after treatment, 150 µg obliterated shivering in all patients. Five minutes after treatment, all patients given 75 µg had stopped shivering. Systolic arterial pressure and heart rate decreased significantly in patients given 75 and 150 µg clonidine. Conclusions:Clonidine (150 µg) and ketanserin (10 mg) both are effective treatment for postanesthetic shivering. The effect of clonidine on shivering is dose-dependent: whereas 37.5 µg had no effect, 75 µg clonidine stopped shivering within 5 min.

High-dose aprotinin reduces blood loss in patients undergoing total hip replacement surgery

BackgroundAprotinin, a proteinase inhibitor, has been reported to reduce blood loss significantly during cardiac surgery. The mechanisms of this effect remain unclear. We studied the effect of aprotinin on blood loss and transfusion requirement during total hip replacement. Potential mechanisms of action and side effects also were investigated. MethodsForty patients scheduled for primary total hip replacement were randomized to receive, in double-blind fashion, either aprotinin given as a bolus of 2 X 104 kallikrein inactivator units (KIU) followed by an infusion of 5 X 105 KIU/h until the end of surgery or an equivalent volume of normal saline. Anesthesia and surgical techniques were standardized and systematic deep venous thrombosis prophylaxis was used. Peri- and postoperative blood loss and transfusion were measured. Fibrinolysis, coagulation pathways, and platelet function were assessed. Renal and hepatic function as well as the incidence of deep venous thrombosis also were assessed. ResultsAprotinin reduced total blood loss from 1,943 ± 700 ml to 1,446 ± 514 ml (P < 0.05). This reduction of blood loss occurred during surgery (P < 0.05) and postoperatively (P < 0.001). Total amounts of blood transfused were 3.4 ± 1.3 units/patient in the control group and 1.8 ± 1.2 units/patient in the aprotinin group (P < 0.001). The activated partial thromboplastin time was significantly prolonged by aprotinin immediately after surgery, at 50.6 ± 12.4 versus 32.3 ± 4.6 s in control patients (P < 0.001), but results of the other coagulation tests were not different between the two groups. No side effects were observed in the aprotinin group. The incidence of deep venous thrombosis in the two groups was not significantly different. ConclusionsThe use of high-dose aprotinin during total hip replacement results in a reduction in both blood loss and the amount of blood transfused. Aprotinins mode of action, however, remains to be elucidated.

Epidural anesthesia impairs both central and peripheral thermoregulatory control during general anesthesia.

BackgroundThe authors tested the hypotheses that: (1) the vasoconstriction threshold during combined epidural/general anesthesia is less than that during general anesthesia alone; and (2) after vasoconstriction, core cooling rates during combined epidural/general anesthesia are greater than those during general anesthesia alone. Vasoconstriction thresholds and heat balance were evaluated under controlled circumstances in volunteers, whereas the clinical importance of intraoperative thermoregulatory vasoconstriction was evaluated in patients. MethodsFive volunteers were each evaluated twice. On one of the randomly ordered days, epidural anesthesia (&OV0312;T9 dermatomal level) was induced and maintained with 2-chloroprocaine. On both study days, general anesthesia was induced and maintained with isoflurane (0.7% end-tidal concentration), and core hypothermia was induced by surface cooling and continued for at least 1 h after fingertip vasoconstriction was observed. Patients undergoing colorectal surgery were randomly assigned to combined epidural/enflurane anesthesia (n = 13) or enflurane alone (n = 13). In appropriate patients, epidural anesthesia was maintained by an infusion of bupivacaine. The core temperature that triggered fingertip vasoconstriction identified the threshold. ResultsIn the volunteers, the vasoconstriction threshold was 36.0 ± 0.2° C during isoflurane anesthesia alone, but significantly less, 35.1 ± 0.7° C, during combined epidural/isoflurane anesthesia. Cutaneous heat loss and the rates of core cooling were similar 30 min before vasoconstriction with and without epidural anesthesia. In the 30 min after vasoconstriction, heat loss decreased 33 ± 13 W when the volunteers were given isoflurane alone, but only 8 ± 16 W during combined epidural/isoflurane anesthesia. Similarly, the core cooling rates in the 30 min after vasoconstriction were significantly greater during combined epidural/isoflurane anesthesia (0.8 ± 0.2° C/h) than during isoflurane alone (0.2 ± 0.1° C/h). In the patients, end-tidal enflurane concentrations were slightly, but significantly, less in the patients given combined epidural/enflurane anesthesia (0.6 ± 0.2% vs. 0.8 ± 0.2%). Nonetheless, the vasoconstriction threshold was 34.5 ± 0.6° C in the epidural/enflurane group, which was significantly less than that in the other patients, 35.6 ± 0.8° C. When the study ended after 3 h of anesthesia, patients given combined epidural/enflurane anesthesia were 1.2° C more hypothermic than those given general anesthesia alone. The rate of core cooling during the last hour of the study was 0.4 ± 0.2° C/h during combined epidural/enflurane anesthesia, but only 0.1 ± 0.3° C/h during enflurane alone. ConclusionsThese data indicate that epidural anesthesia reduces the vasoconstriction threshold during general anesthesia. Furthermore, the markedly reduced rate of core cooling during general anesthesia alone illustrates the importance of leg vasoconstriction in maintaining core temperature.

Pneumothorax During Laparoscopic Fundoplication: Diagnosis and Treatment with Positive End-Expiratory Pressure

Pneumothorax can develop during laparoscopy, particularly during laparoscopic fundoplication, since the left parietal pleura is exposed and can be torn during dissection in the diaphragmatic hiatus.Such an event will result in specific pathophysiologic changes, since CO2, under pressure in the abdominal cavity, will pass into the pleural space. The aim of this study was to document the pathophysiologic changes induced by pneumothorax, and to evaluate the benefit of positive end-expiratory pressure (PEEP) to treat pneumothorax. Forty-six ASA physical status I and II patients scheduled for laparoscopic fundoplication were monitored extensively; heart rate, mean arterial pressure, endtidal CO2 (PETCO2), oxygen saturation of hemoglobin (SpO2), minute ventilation, tidal volume, dynamic total lung thorax compliance, and airway pressures were recorded. In 25 patients, oxygen uptake, CO2 elimination and arterial blood gases were also measured. Pneumothorax was diagnosed in seven patients. It resulted in the following pathophysiologic changes: decrease in total lung thorax compliance, increase in airway pressures, and increase in CO2 absorption. Consequently, PaCO2 and PETCO2 also increased. SpO2, however, remained normal. The use of PEEP largely corrected these respiratory changes. None of these pneumothoraces required drainage. These data suggest that pneumothorax is common during laparoscopic fundoplication. Early diagnosis is possible by simultaneous monitoring of PETCO2, total lung thorax compliance, and airway pressures. Finally, treatment with PEEP provides an alternative to chest tube placement when pneumothorax is secondary to passage of peritoneal CO2 into the interpleural space. (Anesth Analg 1995;81:993-1000)