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PubMed1990

Renal calcium and magnesium handling in experimental diabetes mellitus in the rat.

Metabolic and renal clearance techniques were used to examine kidney function in conscious and anesthetised streptozotocin diabetic rats. All diabetics showed an enhanced calcium and magnesium excretion compared to controls. However, the renal handling of these ions in relation to other electrolytes varied with different experiments. In non-infused conscious rats, the excretion of all ions was higher in diabetics, but the increased output of Ca2+ and Mg2+ was far greater than that of other electrolytes. In infused anesthetised diabetics only the outputs of Ca2+ and Mg2+ were significantly raised. This resulted from a significant reduction in the tubular reabsorption of both ions (% Ca2+ reabsorption: Controls 97.0 +/- 0.5; Diabetics 86.1 +/- 2.1; p less than 0.001). Insulin treatment reversed these changes. Major differences therefore exist in the renal handling of Ca2+ and Mg2+ in control and diabetic kidneys. Such differences do not simply parallel changes in the handling of other ions, and thus represent specific Ca2+ and Mg2+ lesions. Anesthetised infused diabetic rats also showed a reduced glomerular filtration rate and urine output compared to controls. Such differences may relate to an altered fluid balance in the two groups, different responses to surgery and anesthesia, or the degree of hyperglycemia in diabetic animals.

Animals↗

PubMed2002

Cyclooxygenase-2-selective inhibitors in the management of acute and perioperative pain.

Postsurgical pain is often undertreated. Opioids are frequently used in perioperative analgesia, but concern about side effects can result in administration of an inadequate dose for pain relief. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used increasingly for postoperative analgesia. The use of balanced analgesia-a combination of opioids, NSAIDs, and local anesthesia utilizing agents from other classes (eg, ketamine, clonidine)-improves the efficacy of pain relief and decreases risk of side effects. While lacking some of the troublesome side effects of opioids, nonselective NSAIDs may cause bleeding as a result of their inhibitory effects on COX-1. For this reason, COX-2-selective inhibitors (coxibs) are attractive opioid-sparing analgesic options in the perioperative setting. Factors in addition to side effects such as time to onset of action, duration of action, maximum pain relief, use of rescue medication, and other factors relevant to a given pain model are important in determining overall analgesic efficacy. Clinical studies show that COX-2-selective inhibitors are effective for the treatment of preoperative and postoperative pain and reduce postsurgical requirements for opioids. This evidence supports a role for COX-2-derived prostaglandins as key mediators of nociceptive pain and peripheral sensitization (hyperalgesia). Pain management in the perioperative setting and the role of COX-2-selective inhibitors in acute and postoperative pain are reviewed here.

Acute Disease↗

PubMed1990

[A study of hemodynamic effects during dental treatment under local anesthesia. Observation of parasympathetic activity based on the index of R-R interval variation in ECG].

Observing hemodynamic changes occurring during dental treatment performed under local anesthesia is very important. Although many reports on such changes have been made on the basis of blood pressure and heart rate indexes, few have been made on the basis of parasympathetic activity. This is a report of a study on observations of parasympathetic activity on the basis of the index of R-R interval variation in ECG. A multipurpose monitoring system was used to observe and record hemodynamic changes in 52 patients undergoing dental treatment under local anesthesia. In addition, parasympathetic activity was observed on the basis of the index of the coefficient of variation of the R-R interval in ECG (CVR-R = SD/MEAN x 100%). To evaluate R-R interval variations in ECG during dental treatment clearly, comparisons were made between subjects to whom atropine sulfate was administered (prior to treatment) and subjects to whom no drug was administered. In instances of which the subject experiences no unpleasant symptom (for instance, the fainting) during dental treatment, comparative examinations of R-R interval variations in ECG were made at various points during the course of therapy. In instances of which the fainting was induced, examinations of these variations were made during, before, and after the occurrence of the fainting. Results and Conclusions 1. In measuring R-R interval variations in ECG, maintaining stable heart rates and respiratory frequency and depth made it possible to evaluate parasympathetic activity during dental treatment. 2. Consistently low CVR-R values after administration of atropine sulfate clearly showed that patients treated in this way were in a state of parasympathetic blockade. 3. Patients to whom atropine sulfate was administered demonstrated higher values for systolic and diastolic blood pressure and for heart rate than controls: and their posttreatment recovery was slower. 4. Increasing age produced a correlative decrease in CVR-R during both the pretreatment rest period and immediately before treatment. 5. Systolic and diastolic blood pressure and heart rate increased at local anesthesia and maintained such levels until the end of treatment in no fainting cases, however, CVR-R increased just before the end of treatment. This finding leads to the assumption that, as a result of intensified sympathetic activity at the initial stage and the maintenance of this condition, parasympathetic activity increases just before the end of therapy to keep hemodynamic activity in balance.(ABSTRACT TRUNCATED AT 400 WORDS)

Anesthesia, Dental↗

PubMed1989

[Effect of isoproterenol on regional myocardial oxygen balance in dog hearts with coronary stenosis].

Effects of intravenous and intracoronary isoproterenol on oxygen balance in the regional myocardium as well as on coronary hemodynamics were investigated in eight dogs with coronary stenosis under droperidol-fentanyl anesthesia. From these observations, the effect of an increase in myocardial contractility per se on regional myocardial oxygen balance was deduced. After intravenous isoproterenol of 0.5 microgram.kg-1, oxygen tension at the regional subendocardium decreased (23.7--15.4 mmHg) although transmural blood flow increased (26.0--41.4 ml.min-1). Function of the whole heart improved; heart rate increased (85--161 beats.min-1); and aortic blood pressure decreased (94--60 mmHg). After intracoronary isoproterenol of 0.005 microgram.kg-1, oxygen tension at the regional subendocardium slightly but significantly increased (22.8--25.4 mmHg). Although transmural blood flow (27.6--36.6 ml.min-1) and cardiac function improved, heart rate (83--93 beats.min-1) and aortic blood pressure (106--104 mmHg) remained at the pre-isoproterenol level. The results suggest that oxygen balance at the regional subendocardium is deteriorated through tachycardia and hypotension and a vasodilatory effect is seen largely at the subepicardium after isoproterenol to the heart with coronary stenosis, and that an increase in myocardial contractility per se does not deteriorate the oxygenation at the subendocardium.

Animals↗

PubMed2000

Isoflurane alters the recirculatory pharmacokinetics of physiologic markers.

BACKGROUND: Earlier studies have demonstrated that physiologic marker blood concentrations in the first minutes after administration, when intravenous anesthetics exert their maximum effect, are determined by both cardiac output and its distribution. Given the reported vasodilating properties of isoflurane, we studied the effects of isoflurane anesthesia on marker disposition as another paradigm of altered cardiac output and regional blood flow distribution. METHODS: The dispositions of markers of intravascular space and blood flow (indocyanine green), extracellular space and free water diffusion (inulin), and total body water and tissue perfusion (antipyrine) were determined in four purpose-bred coonhounds. The dogs were studied while awake and while anesthetized with 1.7%, 2.6%, and 3.5% isoflurane (1.15, 1.7, and 2.3 minimum alveolar concentration, respectively) in a randomized order determined by a Latin square experimental design. Marker dispositions were described by recirculatory pharmacokinetic models based on very frequent early, and less frequent later, arterial blood samples. These models characterize the role of cardiac output and regional blood flow distribution on drug disposition. RESULTS: Isoflurane caused a significant and dose-dependent decrease in cardiac output. Antipyrine disposition was profoundly affected by isoflurane anesthesia, during which nondistributive blood flow was maintained despite decreases in cardiac output, and the balance between fast and slow tissue volumes and blood flows was altered. CONCLUSIONS: The isoflurane-induced changes in marker disposition were different than those the authors reported previously for halothane anesthesia, volume loading, or hypovolemia. These data provide further evidence that not only cardiac output but also its peripheral distribution affect early drug concentration history after rapid intravenous administration.

Anesthetics, Inhalation↗

PubMed2003

Effect of estradiol sulfamate (ES-J995) on affinity of hemoglobin for oxygen, cardiovascular function and acid-base balance in ovariectomized rats.

Oral administration of estradiol sulfamate (ES, prodrug of estradiol) leads to increased systemic and reduced hepatic effects than estradiol because ES is accumulated in erythrocytes. However, possible alterations of erythrocytic oxygen transport by intraerythrocytic ES accumulation has not been studied. Therefore, ovariectomized adult female rats (n = 58; body wt.) were randomly treated orally either with single doses (day 1) or multiple dose (days 1-4) with vehicle, with estradiol sulfamate (ES-J995, 1 mg x kg(-1) b.w.) or with estradiol (30 mg x kg(-1) b.w.). Under general anesthesia arterial blood pressure, heart rate, blood gases, and acid-base balance were measured. Hypoxia was performed by lowering the inspired fraction of oxygen from 0.35 to 0.12. In addition, individual oxygen dissociation curves and ES-J995 distribution in blood and plasma were estimated. ES-J995 was accumulated in erythrocytes by approximately 98% (P < 0.01), but oxygen transport capacity was not altered (P50: 35.6 +/- 1.0 mm Hg to 37.1 +/- 1.1 mm Hg). Blood gases and acid-base balance parameters were not altered after ES-J995 treatment under normoxic and hypoxic conditions. In conclusion, ES-J995 accumulation in erythrocytes does not alter the affinity of hemoglobin for oxygen nor any function which would indicate an impaired oxygen delivery to the body.

Acid-Base Imbalance↗

PubMed2001

Hemostatic alterations in patients with benign and malignant colorectal disease during major abdominal surgery.

We determined sensitive markers of coagulation and fibrinolysis in plasma of 20 patients with malignant colorectal disease as compared to 17 patients with benign colorectal disease. Thrombin/antithrombin III complex (TAT), soluble fibrin (SF), total fibrinogen and fibrin degradation products (TDP), plasminogen activator inhibitor type-1 (PAI-1), urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR) were measured preoperatively, starting anesthesia, during surgery and postoperatively. The purpose was to verify the supposed hypercoagulable state of cancer patients. In addition, we investigated whether the hemostatic alterations induced by general anesthesia and major abdominal surgery differed between the two groups. Patients with colorectal cancer showed initially an altered balance of hemostasis with a preponderance of procoagulant activity and fibrinolytic inhibition, as noted by marginally elevated TAT and PAI-1 plasma levels. The stimulus of anesthesia induction alone was sufficient to trigger not only activation of coagulation in these patients but also further activation of fibrinolysis and increased fibrinolytic inhibition. The marked activation of coagulation and fibrinolysis and enhanced fibrinolytic inhibition during surgery was more pronounced in patients with malignancy as compared to the control group. Postoperatively, a shift of the normal balance of hemostasis with a slight preponderance of fibrinolytic inhibition was observed, as evidenced by a marginally elevated PAI-1 plasma levels. The results of this study strengthen the hypothesis of a hypercoagulable state in patients with colorectal malignancy that may favor the development of thrombosis in this patient group.

Adult↗

PubMed1978

Cardiac function during induction and early anesthesia with methoxyflurane. An evaluation using systolic time intervals and pressure time indices.

In addition to the standard monitoring of heart rate and blood pressure, the Systolic Time Intervals were used to evaluate cardiac performance, and the Pressure Time Indices (tension time index = TTI; diastolic pressure time index = DPTI) were used to estimate myocardial oxygen balance. Twelve patients with known heart disease were studied during induction with thiopental, intubation, and early anesthesia with methoxyflurane. Cardiac performance diminished after thiopental; and during methoxyflurane it was reflected in increases in pre-ejection period (PEP) and the ratio PEP/LVET. Intubation resulted in a hyperactive state of the heart, as shown by maximal decreases in PEP and PEP/LVET. Myocardial oxygen balance--estimated from the supply/demand ratio (DPTI/TTI)--was impaired after thiopental. After intubation, DPTI/TTI decreased to its lowest value due to an excess of myocardial oxygen demand (TTI) over myocardial oxygen supply (DPTI), signifying a transitory underperfusion of the subendocardium. During methoxyflurane the oxygen balance was gradually restored towards control value. The Systolic Time Intervals and the Pressure Time Indices provided valuable information on cardiac function not available from standard monitoring alone.

Adult↗

PubMed2006

Brief review: coronary drug-eluting stents and anesthesia.

PURPOSE: Anesthesiologists managing patients with drug-eluting stents (DES) face the challenge of balancing the risks of bleeding vs perioperative stent thrombosis (ST). This article reviews DES and the influence of antiplatelet medications related to their use. A perioperative management algorithm is suggested. Novel P2Y12 antagonists currently under investigation, including cangrelor and prasugrel are considered, as well as their potential role in modification of perioperative cardiovascular risks and management of patients with DES. SOURCE: A PubMed search of the relevant literature over the period 1985-2005 was undertaken using the terms "drug-eluting stent", "coronary artery stent", "bare metal stent", "antiplatelet medication", "aspirin", "clopidogrel." PRINCIPAL FINDINGS: Delayed re-endothelialization may render both sirolimus-eluting and paclitaxel-eluting stents susceptible to thrombosis for a longer duration than bare metal stents. Stent thrombosis may be associated with resistance to antiplatelet medication. In patients with a DES, a preoperative cardiology consultation is essential. Elective surgery should be postponed if the duration between DES placement and noncardiac surgery is less than six months. For semi-emergent procedures, both aspirin and clopidogrel should be continued during surgery unless clearly contraindicated by the nature of the surgery. If the risk of bleeding is high, then modification of antiplatelet medications should be considered on a case-by-case basis. CONCLUSION: A profound increase in the number of patients with DES requires anesthesiologists to be familiar with their associated antiplatelet medications, and strategies for risk modification of ST and possible hemorrhagic complications in the perioperative setting.

Anesthesia↗

PubMed2000

Effects of pneumoperitoneum on cardiac autonomic nervous activity evaluated by heart rate variability analysis during sevoflurane, isoflurane, or propofol anesthesia.

BACKGROUND: The effects of pneumoperitoneum on the activity of the cardiac autonomic nervous system have not been completely understood. METHODS: In this study, 45 unpremedicated adult patients who underwent laparoscopic cholecystectomy were anesthetized with either 3.5% sevoflurane, 2% isoflurane, or 8 mg/kg/h propofol (15 patients in each group). The status of cardiac autonomic nervous activity was evaluated by heart rate variability analysis three times: once when the patient was awake, once after induction of general anesthesia, and once after insufflation for pneumoperitoneum. Intra-abdominal pressure was maintained automatically at 10 mm Hg by a carbon dioxide (CO(2)) insufflator. For each measurement, electrocardiogram was recorded for 256 s and played back offline to detect R-R intervals. Power spectral analysis of heart rate variability was applied, and the low-frequency (LF, 0.04-0.15 Hz) and high-frequency (HF, 0.15-0. 40 Hz) bands of the spectral density of the heart rate variability were obtained from a power spectra of R-R intervals using the fast-Fourier transform algorithm. The HF/LF ratio also was analyzed. RESULTS: Measurements of heart rate variability in the three groups showed similar change. Although the power of HF, which represents parasympathetic nervous activity, did not change, the power of LF, which represents both sympathetic and parasympathetic nervous activity, decreased during the anesthetized stage and increased during the insufflated stage. The HF/LF ratio, which represents the balance of parasympathetic and sympathetic activity, increased after induction of general anesthesia, and decreased after insufflation. CONCLUSIONS: Our results suggest that pneumoperitoneum increases sympathetic cardiac activity. The choice of general anesthetic did not seem to have a major influence on the change in the cardiac autonomic nervous system after induction of pneumoperitoneum for laparoscopic cholecystectomy.

Adult↗

PubMed1994

[Anesthetic management of a patient with adrenocorticotropic hormone (ACTH) deficiency].

A 73 year old woman with ACTH deficiency was admitted to our hospital for gastrectomy. She had taken corticosteroid for 3 years. The day before surgery, she took 25 mg of hydrocortisone per os. Hydrocortisone 100 mg was administered intravenously 30 minutes before surgery, during and after surgery, and on the next day after surgery. Serum concentrations of ACTH and cortisol were measured 1 hour after the first administration of hydrocortisone 100 mg, 2 hours after the second and 15 hours after the third administration. The ACTH concentration was always lower than the lowest limit of detection. Cortisol concentrations were 140.0, 180.0 and 14.5 micrograms.dl-1 at each measurement. Serum concentration of aldosterone after the induction of anesthesia was lower than the normal range. Her hemodynamics were very stable and electrolytes balance was not disturbed with corticosteroid treatment during and after surgery.

Adrenocorticotropic Hormone↗

PubMed1996

[Anesthetic management of a patient with ornithine transcarbamylase deficiency].

A 6-year-old female with disturbance of consciousness (JCS: 3 points) due to hyperammonemia caused by ornithine transcarbamylase deficiency is presented. She underwent an emergency insertion of a catheter for peritoneal dialysis under general anesthesia. Anesthesia was induced by intravenous administration of thiamylal sodium and maintained with inhalation of sevoflurane and oxygen after tracheal intubation. One percent mepivacaine was infiltrated around the surgical field to diminish the dose of sevoflurane. The operation proceeded uneventfully, although her consciousness could not recover rapidly to the normal level during the emergence from anesthesia. Peritoneal dialysis was started immediately after the operation and her consciousness recovered to the normal level gradually during the following six days with decreasing plasma ammonia levels. Ten days later, extirpation of the peritoneal catheter was scheduled. The course of anesthesia and operation was uneventful using the same anesthetic method as with the former anesthesia. In the anesthetic management for a patient with ornithine transcarbamylase deficiency, we have to be careful about the nitrogen balance, which can be affected by the kind and doses of anesthetic drugs, to avoid hyperammonemia. From this point of view, local anesthesia combined with general anesthesia might be useful to prevent the serum ammonia level from increasing.

Ammonia↗

PubMed1997

[Influence of fluid replacement on serum magnesium concentration and proper magnesium supplementation during general anesthesia].

We have studied the influence of fluid replacement on serum magnesium (Mg2+) concentrations, and studied proper Mg2+ supplementation during general anesthesia. Thirty eight patients undergoing elective surgery randomly received: Mg(2+)-free acetated Ringer solution (Group I, n = 15), acetated Ringer solution containing 0.5 mmol.l-1 of Mg2+ (Group II, n = 6), 1.0 mmol.l-1 of Mg2+ (Group III, n = 7), 2.0 mmol.l-1 of Mg2+ (Group IV, n = 6), or 4.0 mmol.l-1 of Mg2+ (Group V, n = 4). Measurements were made on serum and urine Mg2+ concentrations during anesthesia. In Group I, the serum Mg2+ concentrations decreased in correspondence with the water balance. It is suggested that dilution due to the fluid replacement induced the reduction in serum Mg2+ concentrations since the observed urine Mg2+ concentrations were negligible. In Group II-V, the reduction in serum Mg2+ concentrations was inhibited by Mg2+ supplementation, and the serum Mg2+ concentrations remained unchanged in Group IV. We conclude the Mg2+ supplementation is required during anesthesia when a large amount of fluid is infused.

Adolescent↗

PubMedDate not supplied

[Characteristics of anesthesia in children operated on for extrahepatic portal hypertension].

Portocaval shunting reliably preventing hemorrhages from esophagogastric veins is most often used in surgery for extrahepatic portal hypertension (EPH) in children. Difficulties of anesthesia for this intervention consists in essential alteration of volume bloodflow as a result of massive outflow of deposited blood to systemic circulation through the new bypass. This necessitates search for an adequate method of general anesthesia and variants of infusion therapy for surgical venous shunting in children with EPH. Sixty-eight children aged 1-15 years with the EPH syndrome were subjected to elective surgery under general analgesia (multicomponent balanced neuroanesthesia with evaluation of some hemodynamic and metabolic parameters). The proposed protocol of general anesthesia in combination with epidural analgesia by local anesthetics and promedole and infusion therapy in the hypervolemic hemodilution mode create the most favorable conditions for adaptation of hemodynamics to increased preloand.

Adolescent↗

PubMed2003

Randomized trial of different intraabdominal pressures and acid-base balance alterations during laparoscopic cholecystectomy.

BACKGROUND: Experimental and clinical studies document risks of acid-base balance alterations toward acidosis and hypercapnia during intraperitoneal carbon dioxide insufflation. The aim of this study was to assess the influence of different insufflation pressures on arterial blood gas changes and acid-base alterations during laparoscopic cholecystectomy and immediately postoperatively. METHODS: Thirty patients were randomized to receive either 10 or 15 mmHg insufflation pressure. Anesthesia was standardized for both groups. The following parameters of acid-base balance were recorded: pH, pCO2, pO2, base excess (BE), HCO3. Suitable data were analyzed by the Mann-Whitney U-test. RESULTS: Pneumoperitoneum with carbon dioxide caused a decrease in pH toward acidosis that was either respiratory or mixed in origin. There were no statistically significant differences in acid-base balance alterations between the two groups of patients. CONCLUSIONS: Carbon dioxide pneumoperitoneum causes alterations of the acid-base balance, mostly of respiratory or mixed type. Lowering of the insufflation pressure from 15 to 10 mmHg does not contribute to the elimination of acid-base balance alterations during laparoscopic cholecystectomy.

Abdominal Cavity↗

PubMed1977

[Electrolyte balance in major abdominal surgery. II. Observations under combined general and regional anaesthesia versus enflurane anaesthesia (author's transl)].

In 20 patients undergoing selective proximal vagotomy using a combination of methohexitone-nitrous oxide-pancuronium-anesthesia and intercostal block, and in 33 patients undergoing large abdominal surgical procedures under enflurane anesthesia, we found a mean decrease in serum potassium after the start of anesthesia of 0.25 mval/l which was maintained during the time of anaesthesia and operation. In spite of an unchanged potassium balance we noted a reduction in red cell potassium in both groups by about 7 mval/l. Serum sodium decreased by about 6 mval/l and base-excess by a mean of 2 mval/l. In both groups we found a nearly indentical and strong correlation between sodium infused and retained. In conclusion changes of serum potassium, serum sodium, base excess, red cell potassium and of sodium and potassium balance are typical of those occurring during large abdominal surgical procedures and the infusion regimen applied. They are, however, not influenced by the type of anaesthesia.

Abdomen↗

PubMed1993

[Effects of clonidine vs trinitroglycerin on myocardial oxygen balance and on pulmonary gas exchange after myocardial revascularization].

The authors examined the effects of clonidine, a preferential alpha-adrenergic agonist, upon myocardial oxygen balance and pulmonary function during the perioperative period in patients undergoing CABG surgery. Anesthesia was provided by fentanyl infusion reaching the final dose of 100 micrograms.kg.min-1 in 10 minutes before skin incision. Ten patients received clonidine 0.125 mg intravenously after induction of anesthesia; a group of 10 patients was managed identically except for nitroglycerin infusion during the pre-CPB period, in order to keep the aortic pressure in the normal range. Intergroup differences in hemodynamics, respiratory data, rewarming time, post-operative ST-tract pattern and enzyme values were evaluated. Results are suggestive (in the clonidine group) for ameliorating myocardial oxygen balance by reducing oxygen consumption indexes (systolic aortic pressure, cardiac index, rate pressure product) and increasing coronary blood flow [coronary perfusion pressure (p < 0.01)] at the end of the surgery and intensive care. Global oxygen consumption reduction, recorded in the clonidine group patients, the oxygen available being unchanged, ameliorated the total oxygen balance mainly after sternotomy (p < 0.05) and at the end of bypass (p < 0.05). Cardiac index was greater during the awakening and rewarming period in intensive care and the ventilatory/perfusion ratio was improved, allowing a minor minute ventilation required in clonidine group patients, specially during admission to intensive care.

Clonidine↗

PubMed2002

Pathogenesis of CO(2) pneumoperitoneum-induced metabolic hypoxemia in a rabbit model.

STUDY OBJECTIVE: To investigate the effects of carbon dioxide (CO(2)) pneumoperitoneum-induced changes in blood gases, acid-base balance, and oxygen homeostasis in rabbits. DESIGN: Prospective, randomized, controlled study (Canadian Task Force classification I). SETTING: University training and teaching center. SUBJECTS: Twenty-six adult female New Zealand white rabbits. INTERVENTION: Anesthesia and pneumoperitoneum. MEASUREMENTS AND MAIN RESULTS: In anesthetized rabbits arterial blood gases, acid-base balance, oxygenation values, and lactate concentrations were assayed during 2 hours. Spontaneous breathing, superficial and optimal ventilation without pneumoperitoneum, and with pneumoperitoneum at low (6 mm Hg) and higher (10 mm Hg) insufflation pressures were compared. The CO(2) pneumoperitoneum profoundly affected blood gases, acid-base balance, and oxygen homeostasis. Carboxemia with increasing end-tidal CO(2) and partial pressure of CO(2) (p <0.001), acidosis with decreasing pH (p <0.001), and base deficiency with decreasing actual base excess (p <0.001), standard base excess and standard bicarbonate and acid excess with increasing hydrogen bicarbonate (p <0.05 and <0.01) were found. Desaturation (p <0.01) with decreasing oxyhemoglobin p <0.05) and hemoglobin oxygen affinity (p <0.01) were also found. Carboxemia with acidosis was more pronounced with higher (p <0.01) than with lower (p >0.05) intraperitoneal pressures, and also with spontaneous breathing (p <0.05) and superficial ventilation (p <0.001) than with optimal ventilation, resulting in metabolic hypoxemia. CONCLUSION: In superficially ventilated and spontaneously breathing rabbits, CO(2) pneumoperitoneum profoundly affected blood gases, acid-base balance, and oxygen homeostasis, resulting in metabolic hypoxemia. With optimal ventilation and low intraperitoneal pressure carboxemia, respiratory acidosis, and changes in oxygen metabolism were minimal.

Acid-Base Equilibrium↗